Focus unit; M_II

For technicians and partly for sales managers!

 

 

These instructions describe the procedures to install and adjust the focus unit for Pannoramic MIDI _II type scanners (M_II).

To help resolve problems with the focus unit a hardware description of the implemented components and adjustment procedures are added.

 

 

The focus unit is designed to fulfill the following tasks

·       Holding the objectives Plan-APOCHROMAT 20x/0.8 and Plan-APOCHROMAT 40x/0.95 in the center of the focus range (realized by the objective changer)

·       Focusing of tissues during the scan process on slides with a slide thickness of 0.95 ~ 1.20mm  (done by the focusing part)

·       Concentrating the illumination light to the field of view (FOV) during brightfield scan procedures (done by the condenser).

·       Insuring a dark background during fluorescent scan procedures (realized by the mechanical shutter)

·       Exchanging the objective magnification between two scan sessions; BF or FL (realized by the objective changer)

 

General

Functional overview

            Principle of focusing

Components and construction

Shutter mechanics

            Principle of shutter mechanics

            Hardware limits and shutter on or off

Adjustment procedures

            Adjust the ex-center position

            Find the hardware limits

            Mount the objective

            Adjust the objective position

            Adjust the condenser position

Dismount or mount the focus unit

 

 

·        For safety regulations regarding human health and scanner functionality please refer to:   Precautions

 

 

 

 

                   Focus unit

 

Modifications since summer 2016

 

Main improvements

  • The slide thickness may be now 1.2mm max; therefore
  • The motor resolution is now 400full-steps or 6400micro-steps/revolution.
  • More details can be found in Improvements_2016

 

          Stepper motors

 

 

 

 

General

 

 

 

 

The described focus unit is a component of the Pannoramic scanner family and contains the following main parts:

·       The focusing part  (driven by the focus stepper motor)

·       The objective with mounting into the objective changer disc

·       The condenser with its position fixing

·       The focusing mechanics (Ex-center, 4:1 divider, Focus pin)

·       The shutter mechanics (Shutter arm, shutter wire, shutter guide)

·       The objective changer unit holds the objectives and allows a consecutive use of different magnifications between two scan sessions.

 

 

The focus unit gives the possibility of focusing the FOV (field of view, seen by the scan camera by 1 exposure) automatically during the scan process of the sample.

 

The unit was developed for the use of objectives of the following types:

 

Plan-APOCHROMAT 20x/0.8      and     Plan-APOCHROMAT 40x/0.95

 

The objective type “Plan-Apochromat” contains several, special chromatically and spherically corrections and delivers so an image of very high color trueness with very small spherical aberration.

 

If the mechanical dimensions do not exceed the size of the Plan-APOCHROMAT 40x0.95 type objective, the mechanical mounting is identical and the focus distance of the objective to the tissue is not closer then 0.25mm, other kind of objectives can be used also but it is strongly not recommended!

 

·       Always check with 3DHISTECH first when a different objective type should be used!

 

The shutter mechanics covers the condenser and this way, during fluoresce scan sessions, the bright field illumination path is broken. The two commands, condenser cover off and condenser cover on are identical with the physical lower and upper limits of the focus unit.

 

 

The exchange of the focus unit is possible

            - If the stepper motor or its electronics for the focus unit is faulty

            - If the shape of any part is deformed or a part is broken.

            - If the focus unit has any fault and you are unable to fix it.

 

 

Requirements                                                                                  

 

Attention        Do not mix the versions of SlideScanner.exe and SlideScannerService.exe! Always use these programs with the same version number. Otherwise the SlideScannerService.exe program could produce unwanted results and SlideScanner.exe does not work correctly or even freeze!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Focus unit with objective changer

 

 

The focus unit with objective changer is developed for Pannoramic SCAN_II and MIDI_II scanners, based on the focus unit of the P250 and is implemented since summer 2016.

·      Connect the cable DOG-1 of the MIDI to the connector “OC control” and connect the cable STG-4 “Turret control” to the turret unit.

 

 

Features

 

The user is able to use different magnifications consecutively for the brightfield and the fluorescent scan procedure likewise,

 

·      Without manual objective exchange.

·      Without objective position adjustments.

·      Without additional optical and illumination adjustments.

·      Exchange of the objective is software controlled and possible between 2 slide scan sessions.

 

Once, the objective settings are defined in the dialog “Microscope Settings” these must not be changed or modified until the objective(s) will be exchanged physically to another type .

 

          Objective changer”; “Configure the scanner”, “Service Program

 

 

 

 

 

 

 

 

 

 

 

 

                   Functional overview

 

Physically, the focus position is defined by the distance of the objective to the tissue. If the tissue is in the focus of the objective, a sharp picture is seen by the camera. Because the tissues are different from each other in thickness and the thickness can change inside the same tissue also, the focus position must be checked and corrected always, during scanning.

 

Furthermore, if the slide will be changed, the specimen holder must be moved away from the objective to avoid collision.

 

If the shutter is changed from shutter off to shutter on, the specimen holder is moved to a position where the focus pin is not in connection with the specimen holder.

During all these actions, except focusing, the objective must be protected against touching and the focus pin as well as the 4:1 divider must be protected against overstraining. This is realized by the focus unit, with the different positions of the focus pin and the positions of the specimen holder; mounted on the X-Y-stage.

 

 

Working distances

As you can see, the gaps between cover slip and objective are very small, especially if the objective Plan-APOCHROMAT 40x/0.95 is used.

The worst case for focusing is defined by the parameters of the 40x objective.

 

Objective position

 

Because the objective in Pannoramic type scanners is mounted in the nominal focus position, we have to move the tissue toward the objective or away from it to find the real focus. It is very important, that the objective position is adjusted well; otherwise, if the objective focus position does not match the focus range, offered by the focus pin movement range, a sharp camera image can never be produced. 

 

          Carl Zeiss GmbH:    Plan-APOCHROMAT 20x/0.8 and Plan-APOCHROMAT 40x/0.95

 

                                               Objectives from Carl Zeiss          Product information, stored

 

 

 

 

                   40x objective

On the scale of the 40x objective, the nominal thickness of the cover slip should be selected.

 

  • If the real thickness of the cover slip differs from the selected value, the quality of the scanned FOV may be reduced!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Objective position

In Pannoramic type scanners the objective is mounted into the middle of the focus range, offered by the movement limits of the focus pin during focusing.

 

  • Because in MIDI_II  scanners the objective position is defined by use of fitting rings, the objective position adjustment is not longer required; the correct objective position is defined during mounting the objectives.

 

 

    Mount the objectives”. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Principle of focusing

 

The slide is hold in the specimen holder. To achieve a parallel movement of the slide in relation to the objective, the specimen holding mechanics contains a parallelogram. This guarantees the position of the tissue to be always perpendicular to the optical axis (parallel to the objective pupil). The specimen holder has a mechanical preload, so the slide has always a connection to the focus pin during scanning.

 

The focus pin is moved by a stepper motor via an ex-center and an 4:1 divider. The resolution of the stepper motor with 6400 steps per revolution, the characteristics of the ex-center and the 4:1 divider allows a very fine resolution of the focus steps and so tissue focusing.

 

Remark

The part, shown with "Compression spring" is replaced by the "Connection spring" and the "Triangle connection".

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Focusing algorithm

 

The focus position of the FOV is found, if the camera sees a sharp image. To reach this, the scan camera takes images in different positions of the entire focus range and the software finds the best focus range. When this range is found the real focus position is found by iteration of the interval.

 

Stepper motor

In opposite to the DESK, MIDI and SCAN, the focus motor of MIDI_II has a resolution of 6400µ-steps/revolution.

 

Home1,2

The Home position of the entire mechanics is situated inside the focus range. The option Home1,2 will never be executed during normal scan operations and is used during system integration only or before  the ex-center fixing bolt will be tightened (if mechanical adjustments are done on the ex-center). In this case, the mounting of the ex-center starts after a Home1,2 execution. This solution is important for protecting the 40x objective.

 

 

          Specimen holders”, “Parallelogram”, “Stepper motor

 

 

 

 

 

 

 

                                      Hardware limits; shutter on and off

  By the use of two shutter arms, one for shutter on, the other for shutter off operation, the hardware limits could be held inside the direction limit for Home1 (less then 3200 steps in each direction). The hardware limits will be reached only during shutter on (CondenserCoverOn = BF light path closed, fluoresce scan) or the shutter off (CondenserCoverOff = BF light path opened, brightfield scan) procedure. To prevent the touching of the 40x objective during the shutter on procedure, the action is executed at a special specimen holder position, where the focus pin is guaranteed between the specimen holder and the slide. This position is X= 27000 steps and Y=18000 steps. This way, the specimen holder practically does not move, during the ex-center crosses the upper peak of the sine wave, because there is no connection between focus pin and slide or specimen holder. Please take this into account if you are working with the service program!!

          How to define hardware limits

 

 

 

 

 

 

 

                   Focus range

In earlier developed scanner systems (DESK, MIDI, SCAN) the step number of the stepper motor was identical with the actual focus position and this was displayed by the software. The focus range in these systems is 800 steps and the positions of the ex-center in relation to the displayed focus range is identical; the physical number of steps is the same as the displayed focus position in the software.

 

Because the resolution of the motor is increased by twice (1 revolution of the motor axle is done in 6400µ-steps), the focus range is now 1600 steps, in the MIDI_II.

Because the focus range is physically counted from -300 steps to +1300 steps, and negative numbers as focus position are unusual, the entire focus range is shifted in the software to the focus range from 1050 to 2650; add to the physical step number 1350. 

 

In the Pannoramic MIDI_II:    SW focus position = HW stepper motor position + 1350.

 

 

          Hardware limits and shutter on or off

 

 

 

 

 

 

 

                      Nominal focus position

 

Because the adjustment of the objective position is no longer required, the nominal focus position is also constant and defined by the used objective position (inserted fitting ring thicknesses). 

 

          Check / adjust the objective position

 

 

 

 

 

 

 

 

 

Scan area

 

 The scan area defines the part of the slide on which the tissue, scanned by the scan camera, is expected to be. The entire scan area is captured by the preview camera in three sections and is shown in the preview area of the program SlideScanner.exe.

The scan area is limited by the mechanical construction of the specimen holder and should be defined as large as possible; it is not defined in relation to the cover slip.

In all cases, the specimen holder should never be touched by the focus pin or the objective! In other words, the scan area is that area of the slide, on which the focus pin and the objective (especially 40x magnification) can be moved seemingly during scanning the tissues, without touching the specimen holder.

 

 

 

Exchange of the objective

 

Because the focus unit is equipped with an objective changer unit, a physical objective exchange procedure is no longer required.

 

          Objective mounting

 

 

 

Specimen holders

 

 Because the physical holding of the slide is different in all three scanner types, the scan area values are different also and they vary from scanner to scanner of the same type also (mechanical tolerances).

In all cases, the scan area values of X-min, X-max, Y-min and Y-max are set just before the focus pin or the objective touches the specimen holder. The accuracy of the limits is 100 steps.

 

The slide is hold by the specimen holder on the longer, lower edge and with a slide clamp on its upper edge, on the barcode area; see the red lines on the right. As you can see, the definition of the limits X-min and Y-max are critical. X-max and Y-min are given by the maximal usable slide size and are not critical; they could be the slide edge.

 

          Specimen holder”, “Areas of the slide”, “Scan area” and “Define the scan area

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Configure the Scanner

 

 

·      Since the software version 1.18 the MIDI and SCAN type scanners requiring configuration parameters.

 

 

[Microscope];                                                                                  MIDI_II

SerialNumber=PMIDI-04xxxx;                                                     Serial number of the scanner

MicroscopeType=3DMic10;                                                      MIDI_II; 

ScanCameraType= ;                                                                      not used, not defined here

PreviewCameraType=CVrmc_m8_pPro;                                  Preview camera type

BarcodeReaderType=PreviewCamera;                                     Barcode capturing is done by the preview camera

LoaderType=SL_1Mag_12Slide_Sensor_Horizontal3;     Slides are hold in the tray with 12 bays and slide sensor used; MIDI_II

CameraChangerType=CC_None;                                             Camera_chancher_VT not present

ReflectorTurretType = RT_3DH_10Pos_Belt;                          Belt driven RTU present

BrightfieldLightSourceType = RGBLedLight;                     FOV Brightfield illumination done by RGB BF-illumination

ObjectiveChangerType=OC_2Pos;                                        Objective changer type with 2 objective positions present

ObjectGuideXYZType = OGXYZ_1.2mm;                              The specimen holder can hold slides with a thickness of 1.2mm maximal

FlashUnitType=NoFlashUnit                                                      Flash illumination unit not present

NDFilterType=ND_None;                                                             ND filter unit not present

PreviewLightType=PreviewLightUnitType_Type3;                 Preview illumination BF only

PowerSwitchBoardType=PowerSwitchBoard_None;             Power distribution and switch electronics not present

 

Following sections and parameters are also implemented

 

[Focus]
NoFocusPinOnTheObjectHolderX=26000
NoFocusPinOnTheObjectHolderY=18000

 

 

[ObjectiveChanger]
ObjectiveChangerTimeout=7000

 

          If MIDI OC:                MicroscopeConfiguration.txt

 

                        Handling the *.ini files”; “Service Program

 

 

 

 

 

 

 

 

 

Components; construction

 

Stepper motor

Ex-center and focus plate

Focus plate and 4:1 divider

4:1 divider and focus pin

Objective mounting

Cover tube

Condenser and mounting

 

 

 

 

 

 

                   Stepper motor

 

The stepper motor of the focus unit has a resolution of 3200 steps and drives:

·       via the ex-center, the focus mechanics (see “Principle of focusing”) and

·       via the shutter arm, the mechanical shutter (see “Principle of shutter mechanics”).

 

The forward direction of the motor’s axle is clock wise, CW (the software inverts the real direction). The command and status relevant information for the focus unit like step number and direction; go to Home1,2 or go to shutter on or shutter off are received from the stepper motor’s electronics via the cable STX-3 (X stands for the actual hardware version and depends on the scanner type also).

 

·       The address of the focus motor in S_M_D is always 05.

 

·       The parts and units of the stepper motors need neither maintenance nor mechanical adjustments.

 

          Stepper motor implementation”, “Addresses”, “Cabling of addressable units” and “USB-controller cabling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Ex-center and focus plate

 

The motor axle of the stepper motor rotates the ex-center on which the focus plate is mounted and this moves the 4:1 divider.

 

·       The ex-center position is correct, if 1600 focus steps are moved and the shutter arm stays in the middle of the slot. If this condition is not met, please adjust the ex-center position more precise (maximal tolerance is 10steps).

 

·       The bearing of the 4:1 divider and the ball-headed pin of the focus plate eliminates the unwanted left and right movement.

 

 

 

Attention

The mounting bolts of the focus plate should not be loosened; here the position of the focus plate and so the position of the 4:1 divider and the position of the focus pin is adjusted!

Because the movement range of the focus pin is very small, the adjustment of the focus pin position is delicate; the focus plate mounting bolts position must not be altered.

 

·       The adjustment of the focus pin position can not be done in the field!

 

 

 

 

 

 

 

 

 

 

 

                   Focus plate and 4:1 divider

 

The connection between focus plate and divider is realized with a ball-headed joining because the ex-center does an up-down and additionally a left-right movement.

 

·       The Connection spring with the triangle connection ensures a hysteresis-free connection.

 

Furthermore, on the ex-center mounting the shutter arm is situated for the shutter off and on operation and defines so in the same time, together with the shutter wire the hardware limit for the focus unit.

 

 

                   4:1 divider and focus pin

 

On the other end of the 4:1 divider the focus pin is realized. The focusing of the tissue is done by moving the focus pin (and so the tissue) toward or away from the objective. Because the focus pin touches the slide always during focusing, the distance of the slide with tissue to the objective is modified until the focus position is found. The mechanical construction allows a focus pin movement of 0.288mm around the nominal focus position during focusing (focus range from 1050 – 2650steps).

The increased focus pin movement is required, because the slide thickness is increased and may be 1.2mm.

 

 

 

 

 

 

 

 

 

                   Objective mounting

 

The objective disc contains 2 drillings with M27 thread, so the objective can be mounted directly.

The distance of the objective to the focus pin (the objective position) is adjusted by using fitting rings between the objective mounting surface and the objective disc surface.

 

The nominal distance is 0.3mm.

By using and combining fitting rings of different thicknesses, the objective position can be adjusted individual (not recommended!).

 

If the objective was removed, please insert the 20x objective into the mounting with the marker again, the objective position was adjusted with this condition.

 

 

          Working distances” and “Exchange the objective SCAN, MIDI, DESK

 

Carl Zeiss GmbH:    Plan-APOCHROMAT 20x/0.8 and Plan-APOCHROMAT 40x/0.95

 

                                               Objectives from Carl Zeiss          stored PDF-file; Product information

 

 

 

 

 

 

 

Set of objective fitting rings

 

Name                          SHIMS SET FOR M27 OBJECTIVE

Article number      AC-OBJ-SHM-0100

Content                   Nominal objective position is reached if the thickness of the fitting ring is 0.3mm!

 

                   2x     0.3mm; already implemented

                   4x     0.1mm

                   2x     0.05mm

 

By using and combining appropriate fitting ring thicknesses the distance of the objective to the tissue can be adjusted in steps of 0.05mm.

                                                                                                                                                                

·      Please use always the same distance of the objective to the tissue on both objectives!

·      Because the Objective distance is already adjusted (with the fitting rings of 0.3mm), the implemented fitting rings are not found in the set, delivered with the scanner!

 

 

 

 

 

 

 

 

 

                   Mount the objectives

 

Important

Principally, the objective position is already adjusted during the system integration process and modification of the objective position should be done only in exceptions;

 

modification is strongly not recommended!

·      If the objective(s) are dismounted, please leave the fitting ring(s) on the objective (to avoid a mismatch)!

·      Always drive the 20x objective into the marketed position, see above!

·      Always drive in the objective until it stops!

 

The focus position of both objectives is found in the nominal focus position for the appropriate slide thickness within a tolerance of ±50 focus steps!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Dummy objective

If the option 40x magnification is not used, the dummy objective is implemented in the objective position 2.

This way, a weight displacement of the objective disc will be avoid.

  • If a weight displacement of the objective disc would occur, the form-fit mechanism would not work correctly and the objective may be misaligned in the optical axis.

 

 

 

 

Mount the 20x objective always into the position 1 and the 40x or dummy objective into the position 2.

  • Because in all systems always a 20x objective is used (the 40x objective is optional) the start-up procedure of the software calibrates the system with the 20x objective.
  • Furthermore, all the optical and preview adjustments are based on the 20x objective.

 

  • The objective positions 1 and 2 are decided, if the drive unit will be mounted; see also “Check / Set the working position 1”

 

Remark

Since the software version 1.16 the BF scan session may be executed with the 20x or the 40x objective likewise.

 

See also:       Upgrade to the software version 1.16” and “What is new” “Brightfield scan with the 40x objective

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The software setup of the objectives is done in the dialog “Microscope settings”, there will be defined if the 40x objective is present or not.

 

          Pannoramic_250_1.15_User's_Guide_EN_Rev1_FINAL.pdf

 

 

Remark

In the dialog “Microscope settings”, any objective (20x or 40x) can be set to any position (objective position 1 or 2), but we recommend the use of the objective 20x in the position 1 and the 40x or dummy objective in the position 2, because some adjustments (e.g. the preview calibration procedure) requires the existence of the 20x objective in the position 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Cover tube

 

·    The image path cover tube exists in two versions; depending on the existence of the turret unit, whether the shorter or the longer tube is used.

·    The shorter cover tube is mounted directly onto the objective nut, in opposite of the objective.

·    The longer cover tube is used if the turret unit is not implemented and is mounted into the camera tube mounting; on the opposite side of the camera tube.

·    The image path cover tube is used in the SCAN and the MIDI only; in the DESK a cover tube is not required.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Condenser

The condenser concentrates the incoming light to the field of view (FOV).

Because the size of the illuminated part of the tissue is critical, the condenser position can be adjusted; the focus position is 10.9mm nominal.

 

    Condenser              Wikipedia

                  condenser position adjustment.

 

·    Maintenance is not required

 

 

 

 

 

 

 

 

 

 

 

 

Condenser and mounting

In the DESK and the MIDI, in opposite to the SCAN, the condenser is arranged in vertical position. In this case, if the mounting bolt is loosened and the condenser is driven out of the mounting, the condenser may fall out of the mounting and might damage the illumination mirror of the DESK or the MIDI.

 

 

Important

·       Please protect the illumination mirror by inserting a slide between scanner plate and focus unit if the fixing bolt will be loosened or protect the condenser otherwise against falling out.

·       In the adjusted condenser position, the condenser housing looks only a little bit over the mounting.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Shutter mechanics

 

 

 

 

 

The mechanical shutter is implemented as a part of the focus unit and the shutter guide is situated between condenser and 4:1 divider.

 

During fluorescent scan the shutter must be closed and insures so a dark background. Other, unwanted fluorescent materials (e.g. painting, optics) can not reflect the fluorescent light or can not fluoresce and so they will not disturb the fluorescent view.

 

During bright field illumination the shutter must be fully open to ensure a bright and evenly illumination of the FOV.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Principle of shutter mechanics

 

The shutter has only two usable states, shutter on and shutter off. These positions are identical with the hardware limits of the focus unit; in these positions the bright field illumination (the condenser) should be fully opened or fully covered respectively. All other possible positions of the shutter are not defined, therefore faulty positions and not allowed during the scan process.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

If the shutter wire is touched by the shutter arm, the torsion is transmitted via the shutter wire to the slider of the shutter guide. The slider brings so the shutter guide into the proper position.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Shutter arm position

 

During rotation of the stepper motor axle in direction to the negative limit of the focus unit, the shutter wire will be touched by the shutter arm and is so moved to the shutter off state (bright field illumination allowed). If the stepper motor axle is rotated in direction to the positive limit, the other shutter arm will touch the shutter wire from the opposite direction and moves so the shutter guide to the shutter on position (bright field illumination disabled).

In practice it means, that the shutter wire together with the shutter arms is the limiter of the focus mechanics and with this limiter the shutter on and shutter off option is realized.

 

·       During focusing the shutter wire will never be touched by the shutter arm.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Adjustment procedures

 

 

The following procedures are described especially for Pannoramic SCAN. In Pannoramic MIDI the adjustments are logically identical, but some terms like “up, down, top, bottom, left, right, horizontal and vertical” differ. Please take this into account if you are adjusting the MIDI. The term “SMD_II” stands for SCAN_II, MIDI_II and DESK_II.

 

 

 

                   Adjust the ex-center position

 

This adjustment must be done only if the ex-center was dismounted or the fixing bolt was loosened. With this adjustment the focus position is set to be +500steps nominal.

Because in this position the fixing bolt can not be loosened or tightened, we use the focus stepper motor position of 2100 steps for this adjustment.

 

 

1.      Loosen the ex-center fixing bolt so, that the ex-center can be rotated and moved on the motor axle.

 

2.      With the service program set the focus unit to Home1,2.

 

3.      Go forward to the focus motor position 2100 steps.

 

4.      Bring the ex-center into the vertical position (the shutter arms shows up and down; use the slot of the focus plate mounting to find the proper position. Before you are tighten the ex-center fixing bolt please check the position of the shutter arm in relation to the shutter wire (hook) also. The shutter arm should touch the shutter wire nearly in the middle of the hook. To reach this, shift the ex-center in proper position on the motor axle and tighten the fixing bolt.

 

 

 

 

 

 

 

 

 

Attention

 

 A small gap between motor mounting surface and ex-center mounting should exist, otherwise, if the ex-center mounting rubs on the motor mounting surface, the focus unit may lost rotor movements and so the scanned tissue may be out of focus or blurry, even if the focus rotor direction had changed.

 

5.      Go to the positions Home1,2.

 

6.      Go forward to the focus motor position +2100steps.

 

7.      In this position the shutter arms should showing exactly up and down. A deviation of max. 10 steps from the vertical direction is allowed. If the deviation is too much, repeat the adjustment from step 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Find the hardware limits for the focus unit

 

This procedure must be done only if the ex-center was dismounted or its fixing bolt was loosened. Before the following procedure is done, the previous adjustment “Adjust the ex-center position” should be correct.

 

          Hardware limits; shutter on and off

 

 

 

 

Find the negative limit

 

8.      With the service program set the focus unit to Home1,2.

 

9.      Go forward to the focus motor position -1750 steps.

 

10.  Go backward +1750 steps.

 

11.  Press Home1 (only). There should be not more then +-2 steps difference to Home1.

If there are more steps lost, decrease the actual number of steps by 10 and repeat from step 8. In the steps 9 and 10 use the actual number of steps!

 

12.  If there are not more then 2 steps difference to Home1, increase the number of steps by 10 and repeat from step 8. In the steps 9 and 10 use the actual number of steps!

 

13.  The negative limit is found correctly if the motor movement has no steps lost and the actual number of steps, increased by 10 would produce lost steps.

The found negative limit can differ by more ten steps from unit to unit. The reasons are the tolerances of the components and the used position of the ex-center in relation to the motor axle.

 

14.   Update the parameter value of the parameter “FocusDeviceMin” with the found number of the actual steps in the file “MicroscopeConfiguration.ini” section [HardwareLimits].

 

15.  Update the parameter value of the parameter “CondenserCoverOff” with the found value in the file “MicroscopeConfiguration.ini” section [Focus].

 

 

 

 

 

 

Find the positive limit

16.  With the service program set the focus unit to Home1,2.

 

17.  Go forward to the focus motor position +2750 steps.

 

18.  Go backward 2750 steps.

 

19.  Press Home1 (only). There should be not more then +-2 steps difference to Home1.

If there are more steps lost, decrease the actual number of steps by 10 and repeat from step 16. In the steps 17 and 18 use the actual number of steps!

 

20.  If there are not more then 2 steps difference to Home1, increase the number of steps by 10 and repeat from step 16. In the steps 17 and 18 use the actual number of steps!

 

21.   The positive limit is found correctly if the motor movement has no steps lost and the actual number of steps, increased by 10 would produce lost steps.

The found positive limit can differ by more ten steps from unit to unit. The reasons are the tolerances of the components and the used position of the ex-center in relation to the motor axle.

22.  Update the parameter value of the parameter “FocusDeviceMax” with the found value in the file “MicroscopeConfiguration.ini” section [HardwareLimits].

 

23.  Update the parameter value of the parameter “CondenserCoverOn” with the found value in the file “MicroscopeConfiguration.ini” section [Focus].

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Dismount; mount the focus unit

 

 

 

 

                   Focus unit mounting

The mounting of the focus unit with objective changer is realized with dovetail; the unit is hold by a dovetail fixing clamp.

 

  • Rotate the screw driver clockwise to open (loosen) the dovetail clamp.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Dismount the focus unit

 

  • Make sure, that the X-Y-Stage is not in the X-home position, because in this position the focus unit can not be removed.

 

1.      With the service program go forward to the position 10,000 steps in +X direction (3 revolutions of the motor axle).

 

2.      Disconnect the bus cables DOG-1 of the objective changer and STG-4 of the turret stepper motor.

 

3.      Disconnect the cable of the focus motor.

 

4.      Loosen the fixing bolt of the focus unit mounting; turn the screw driver clockwise!

 

5.      Remove the entire focus and objective changer unit by pulling the unit backward.

 

            Watch Video:           Remove focus unit (M_II)

 

Remark

The focus unit can be removed without removing other units!

 

                   Mount the focus unit

 

6.      Insert the focus unit with objective changer into the dove tail of the scanner plate until the physical limit is reached; take care on the objectives.

 

7.      Tighten the fixing bolt of the focus unit mounting; turn the screw driver counter clockwise!

 

8.      Connect the bus cables DOG-1 of the objective changer and STG-4 of the turret stepper motor.

 

9.      Connect the cable of the focus motor.

 

            Watch Video:           Mount focus unit (M_II)

 

 

 

 

 

 

 

 

 

 

 

 

Objective changer part

 

 

The objective changer part of the focus unit consists of:

 

 

Important

The drive unit can be separated from the objective changer mechanics unhesitatingly, but do not remove the objective changer mechanics from the focus part; see Align the objective into the optical axisfirst!

 

 

 

 

 

            Watch Video:           Objective changer; assembling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Functional overview and construction

 

The following chapters, concerning the objective changer are true for the “MIDI with objective changer” (3Dmic10) and “SCAN with objective changer” (3Dmic11) also.

 

 

                   Drive unit (top view)

 

The transport disc is rotated by the DC motor; always in the mathematical positive direction, if we are looking onto the objectives (during normal work).

The transport disc moves the transport pins situated in the transport holes, by a half revolution.

Just before the working position of the objective is reached, the DC motor will be switched off by the appropriate sensor and the final movement, into the exact working position (into the optical axis), is done by the form-fit mechanism.

 

  • The transport disc can be rotated manually, but do it carefully!
  • The unit does not need maintenance or adjustments.

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Electronics cover

The spacer in the electronics cover keeps a distance between cover and PCB and avoids so a shortcut in the electronics.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Drive unit (from beneath)

 

  • The control electronics get its information via the cable DOG-1 and the bus connector; the bus is prolonged to the turret unit via the cable STG-4.

 

 

  • The objective changer type is defined in the file “MicroscopeConfiguration.ini” in the section:

 

[Microscope]

.

.

.

ObjectiveChangerType=OC_2Pos

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Objective changer mechanics

 

  • The objective disc holds the objectives and is driven by the fitting pins.
  • The form-fit arm, together with the ball bearing of the fitting pin guarantees the proper and constant objective position in the light path, even if the objective has been exchanged.
  • The objective position can be adjusted by the help of fitting rings.
  • The unit mounting of the objective changer mechanics should not be loosened or removed, because the working position of the objective in relation to the optical axis is adjusted here;

 

 

    Align the objective”.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Objective position sensors

 

 

As mentioned above, on the top of the transport disc two permanent magnets are situated; the distance to each other is exactly 180 degrees (not shown correctly).

Just before the working position of the objective is arrived and the dead point of the form-fit mechanism is even crossed, the permanent magnet arrives over the sensor and stops so the movement of the transport disc.

 

  • Each objective (position) has its own sensor and its own permanent magnet also; the positions are named as “Objective position 1” and “Objective position 2”.
  • In the objective position 1 always the 20x objective has to be mounted; in the objective position 2 the dummy objective or the 40x objective is situated.
  • The objective positions 1 and 2 of the objective disc are decided, if the drive unit will be mounted; see also “Mount the objective changer drive unit”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Adjustable permanent magnet position

 

 

In scanners, manufactured since June 2013, the position of the permanent magnet is adjustable.

 

With this solution, and by adjusting the magnet position, the dead point of the form-fit mechanism can be always reached surely.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Position of permanent magnet

·      If one permanent magnet position is moved backward (or forward) the permanent magnet in the opposite position should be moved also backward (or forward) by the same distance!

·      To reach a correct adjustment, the distance of the permanent magnets to each other has to be always 180º!!

 

 

With this solution, and by adjusting the magnet position, the dead point of the form-fit mechanism can be always crossed surely.

 

          “Adjust permanent magnet position”

 

Watch video:                        P250_Objective change

 

 

·      If one permanent magnet position is moved backward (or forward), the permanent magnet in the opposite position should be moved also backward (or forward) by the same distance!

·      To reach a correct adjustment, the distance of the permanent magnets to each other has to be always 180º!!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Adjust permanent magnet position

 

With the service program rotate the Transport Disc in forward direction.

If the motor is switched off, the form-fit mechanics should act and the final objective position should be reached surely.

Otherwise, a small gap should also exist between transport hole and transport pin, if the objective stays in the optical axis.

 

Check this behavior in both objective positions several times with the service program!

 

Watch video:                        P250_Objective change

 

 

·      If one permanent magnet position is moved backward, the permanent magnet in the opposite position should be moved also backward by the same distance!

·      To reach a correct adjustment, the distance of the permanent magnets to each other has to be always 180º!!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Objective disc

The objective disc realizes the exchange of the objective between two slide scanning sessions.

 

If the transport disc (not shown) rotates by a half revolution, the objective disc will be rotated also as long as the connection between transport hole and objective fitting pin exists. The force of the form-fit mechanism is defined by its spring and this holds so the objective (the ball bearing of the fitting pin) always in the proper position until a new objective change command is executed.

 

 

·       The objective disc can be rotated manually in any direction to reach the required objective position.

·       The form-fit mechanism should always fix the objective position; otherwise, the optical axis will be incorrect!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Form-fit mechanism

 

The form-fit mechanism acts in the transport disc’s stop position; the final objective position (the real working position) will be reached and the fitting pins will be disconnected from the transport holes.

The force of the spring as well as the shape of the form-fit arm guaranties always the proper and constant position of the objective in relation to the optical axis.

 

 

    Align the objective

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The disc is always driven in direction from the spring to the mounting of the form-fit arm; the reason for this is the shape of the form-fit arm.

The use of ball bearings on essential, important mountings guarantees the proper position of the objective in the image path.

 

If the ball bearing of the fitting pin arrives to the form-fit arm, and the dead point of the form-fit mechanism is even crossed, the transport wheel stops the movement and the ball bearing of the fitting pin will be locked in the shape of the form-fit arm by the force of the spring.

 

 

 

 

The transport hole of the transport wheel moves the objective disc with the help of the objective fitting pin until the appropriate magnet arrives over its sensor. This position is so defined, that the dead point of the form-fit mechanism is even crossed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Objective mounting

The objective disc contains 2 drillings with M27 thread, so the objective can be mounted directly.

The distance of the objective to the focus pin (the objective position) is adjusted by using fitting rings between the objective mounting surface and the objective disc surface.

 

The nominal distance is 0.3mm.

By using and combining fitting rings of different thicknesses, the objective position can be adjusted individual; but this is strongly not recommended for Plan_APOCHROMAT type objectives.

 

If the objective was removed, please insert the 20x objective into the mounting with the marker again, the objective position was adjusted with this condition.

 

 

 

 

 

 

 

 

 

 

 

 

 

Set of objective fitting rings

Name:                         SHIMS SET FOR M27 OBJECTIVE

Article number:     AC-OBJ-SHM-0100

 

Content:                  Nominal objective position is reached if the thickness of the fitting ring is 0.3mm!

 

                   2x     0.3mm; already implemented

                   4x     0.1mm

                   2x     0.05mm

 

By using and combining appropriate fitting ring thicknesses the distance of the objective to the tissue can be adjusted in steps of 0.05mm.

 

·      Please use always the same distance of the objective to the tissue on both objectives!

·      Because the Objective distance is already adjusted (with the fitting rings of 0.3mm), the implemented fitting rings are not found in the set, delivered with the scanner!

 

 

 

 

 

 

 

 

 

                   Mount the objectives

 

Important

 

Principally, the objective position is already adjusted during the system integration process and modification of the objective position should be done only in exceptions; modification is strongly not recommended!

·      If the objective(s) are dismounted, please leave the fitting ring(s) on the objective (to avoid a mismatch)!

·      Always drive the 20x objective into the marketed position, see above!

·      Always drive in the objective until it stops!

 

The focus position of both objectives is found in the nominal focus position for the appropriate slide thickness within a tolerance of ±50 focus steps!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Dummy objective

 

If the option 40x magnification is not used, the dummy objective is implemented in the objective position 2.

This way, a weight displacement of the objective disc will be avoid; mainly used in SCAN and P250-type scanners.

  • If a weight displacement of the objective disc would occur, the form-fit mechanism would not work correctly and the objective may be misaligned in the optical axis.

 

 

 

 

Mount the 20x objective always into the position 1 and the 40x or dummy objective into the position 2.

  • Because in all systems (M_II, S_II) always a 20x objective is used (the 40x objective is optional) the start-up procedure of the software calibrates the system with the 20x objective.
  • Furthermore, all the optical and preview adjustments are based on the 20x objective.

 

  • The objective positions 1 and 2 are decided, if the drive unit will be mounted; see also “Check / Set the working position 1”

 

Remark

Since the software version 1.16 the BF scan session may be executed with the 20x or the 40x objective likewise.

 

          Upgrade to the software version 1.16” and “What is new” “Brightfield scan with the 40x objective

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The software setup of the objectives is done in the dialog “Microscope settings”, there will be defined if the 40x objective is present or not.

 

 

          Pannoramic_250_1.15_User's_Guide_EN_Rev1_FINAL.pdf

 

 

Remark

In the dialog “Microscope settings”, any objective (20x or 40x) can be set to any position (objective position 1 or 2), but we recommend the use of the objective 20x in the position 1 and the 40x or dummy objective in the position 2, because some adjustments (e.g. the preview calibration procedure) requires the existence of the 20x objective in the position 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

Setup and define the implemented objectives

 

 

 

 

If the objective(s) are implemented and the program “SlideScanner.exe” finished the start up procedure, select the option “Microscope Settings” in the menu “Options”.

 

  • The setup of the objective(s) is done mostly together with the install of the present cameras.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In the dialogue “Base Settings” the implemented objectives are selected and parameterized.

 

By default

  • Select the type “Plan-Apochromat” (1) and the magnification of 20x (2) in the objective position 1
  • Select the type “Plan-Apochromat” (3) and the magnification of 40x (4) in the objective position 2.

§         If there is only a 20x objective implemented into the scanner, select “<none>” (3) in the objective position 2.

 

Remark

Of course, the dialogue accepts any kind of magnification in any objective position, but in the MIDI_II the 20x objective should be always in the objective position 1 because this is the default objective and some adjustment procedures (e.g. the preview calibration process) uses the 20x objective in the objective position 1!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Mount the objective

 

·       To exchange the objective, please see  Objective mounting

 

                   Adjust the objective position

 

This adjustment assumes that the focus mechanics is fully adjusted.

 

·       Adjustment of the objective position in no longer required.

·       The position of the Plan-APOCHROMAT type objective is already adjusted by the use of the fitting ring of 0.3mm in each objective position!

·       In exceptions the objective position might be adjusted with the delivered fitting rings of the set.

 

Important

Adjustment of the objective distance to the tissue might be required if another objective type is used (other than Plan-APOCHROMAT)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                            Adjust the condenser position

 

The adjustment of the condenser is important for the bright, uniform and optimal illumination of the FOV. This reduces so the exposure time of the camera and increases the quality of the scanned tissue. If the objective position was modified, the correctness of the condenser position has to be checked again!

 

·       This adjustment assumes that the entire focus unit is adjusted and the correct objective position is found; this should be always the last adjustment of the focus unit.

 

See also:       Condenser and mounting

 

1.      Create a live view with the scan camera in the focus tab and set the focus motor position to 1600 steps.

 

2.      With the preview positioning tool  find a “clean” FOV outside the tissue and inside the cover slip, without dust.

 

3.      Loosen the condenser’s fixing bolt.

 

 

4.      Rotate the condenser toward to the objective, to find the start position for the adjustment; the brightness will increase.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5.      Rotate the condenser in opposite direction and look at the live view. Beware of the condenser cover (mechanical shutter), don’t close it and don’t bend it. You will see two surfaces (from the diffuser) coming into focus (see “Condenser 1 and 2”). While rotating the condenser you can also observe that the brightness decreases.

 

 

 

6.      After the second surface just disappeared (Condenser 2) and the live image is smooth and bright (“Condenser position”), stop moving the condenser and tighten its fixing bolt (the image was done with previously adjusted illumination. If you are starting the adjustment, the figure “Condenser position” might be is not so smooth).

 

 

 

 

7.      If the brightness decreased too much, repeat from step 3.

 

 

 

 

 

 

 

 

 

 

 

Check the shutter closed position

·    During a fluorescent FOV is visible on the screen as a live view, switch on and off the bright field illumination several times with the service program. If the shutter is in proper position the brightness of the view must not change.

 

 

 

Check the shutter open position

 

·    During LUT-adjustment the FOV is visible on the screen as a live view. Try to bring the shutter wire manually more into the shutter off position (the -300 limit) and observe the screen. If the shutter is in proper position the view of the LUT adjustment must not change.

 

Remark

·      If the illumination path is partially cut by the incorrect shutter position, an evenly illumination of the FOV will never be reached! This is true for all scanner types.

 

 

 

 

 

 

 

 

 

 

 

 

 

Align the objective into the optical axis

 

 

 

 

Attention

The alignment of the objective position to the optical axis is already done and finished; this is not a usual adjustment.

 

The following calibration should be done only, if the objective changer unit mounting was loosened, altered or the objective changer unit was separated and reassembled to the focus unit; so the optical axis will not be strait.

 

  • The following procedure will be used to fit the objective (position) into the optical axis correctly.
  • In any cases, check the alignment first, before starting the adjustment.
  • Check the correct working of the form-fit mechanics also.

 

Remark

The aligning procedure is advised and described for the 20x objective and the objective position 1.

If the 20x objective position is equipped with an objective nut using Whitworth thread, you can use unhesitatingly the 40x objective position to align the objective changer unit!

 

 

 

 

 

 

 

 

 

                   Alignment tools

 

The alignment is done mechanically; the objective pupil position (represented by the drilling of the objective aligner) will be fit into the optical axis by the help of the condenser aligner pin. During this fitting operation the objective changer unit mounting is barely loosened (except you are checking the correctness of the alignment). The unit mounting bolts will be tightened, if both adjustment tools fitting easily and the form-fit mechanics fix the objective position correctly.

 

  • In all cases, the lock nut of the objective mounting nut as well as the objective aligner should be fully tightened during the aligning procedure.
  • The alignment tools can also be used to check the objective position alignment if the objective changer unit mounting is tightened!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   Check the alignment

 

1.      With the service program set the objective changer into the default position by pressing the radio button “Sensor 1” and the button “Forward” of the tab “Objective changer”; the objective 20x should be in the working position.

2.      Disconnect the cables of the objective changer and the stepper motor cables.

3.      Remove the entire focus unit with the objective changer.

4.      Remove the drive unit.

5.      Rotate the objective disc manually by about a ¼ revolution and remove the 20x objective; do not loosen the lock nut or the objective mounting nut; otherwise the objective position has to be adjusted again!

6.      Drive the objective aligner into the objective mounting of the 20x objective until it stops.

7.      Mark the condenser position (e.g. with a pen), then remove the condenser.

8.      Make sure, the mechanical shutter is open.

9.      Insert the condenser aligner into the condenser mounting.

10. If the condenser aligner moves easily in / out in the condenser mounting (if it would falling out by gravity) and the form-fit mechanics fix the objective position correctly, the adjustment is correct.

11. If the condenser aligner can not be inserted or moves strong, the objective is misaligned; execute the aligning procedure.

12. If the aligning result is acceptable, remove the condenser aligner and mount the condenser again (until the previously signaled position).

13. Remove the objective aligner and mount the 20x objective again.

14. Put the 20x objective into the working position manually and mount the drive unit.

15. Mount the entire focus unit with objective changer and connect the cables.

16. With the service program check the functionality of the focus unit and the objective changer unit as well, the 20x objective have to be in the working position if ‘Sensor 1” was selected.

17. Check or adjust the objective position.

18. Check the focus position

19. Check or adjust the condenser position.

 

 

 

 

 

 

                   Aligning procedure

1.      With the service program set the objective changer into the default position by pressing the radio button “Sensor 1” and the button “Forward” of the tab “Objective changer”; the objective 20x should be in the working position.

2.      Disconnect the cables of the objective changer and the stepper motor cables.

3.      Remove the entire focus unit with the objective changer.

4.      Dismount the drive unit.

5.      Rotate the objective disc manually by about a ¼ revolution and remove the 20x objective; do not loosen the lock nut or the objective mounting nut; otherwise the objective position has to be adjusted again!

6.      Drive the objective aligner into the objective mounting of the 20x objective until it stops.

7.      Mark the condenser position (e.g. with a pen), then remove the condenser.

8.      Loosen the unit mounting bolts of the entire objective changer unit so, that the unit becomes barely moveable.

9.      Make sure, the mechanical shutter is open.

10. Insert the condenser aligner into the condenser mounting and adjust the entire objective changer unit position in relation to the focus unit.

11. If the condenser aligner moves easily in / out in the condenser mounting (if it would falling out by gravity) and the form-fit mechanics fix the objective position correctly, the unit mounting bolts should be tightened.

12. Check the easily movement of the condenser aligner in the condenser mounting again; hereby the form-fit mechanics should fix the objective position correctly also.

13. If the condenser aligner moves strong, repeat this procedure from step 8.

14. If the aligning result is acceptable, remove the condenser aligner and mount the condenser again (until the previously signaled position).

15. Remove the objective aligner and mount the 20x objective again.

16.  Put the 20x objective into the working position manually and mount the drive unit.

17. Mount the entire focus unit with objective changer and connect the cables.

18. With the service program check the functionality of the focus unit and the objective changer unit as well, the 20x objective have to be in the working position if the radio button “Sensor 1” and the button “Forward” of the tab “Objective changer” was pressed.

19. Check / adjust the objective position.

20. Check the focus position

21. Check / adjust the condenser position.