JP2010066006A - Automatic slicer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic slicer capable of making favorable sliced pieces while reducing time for cutting blades to swing without cutting to improve working efficiency by accurately and promptly adjusting the relative position between a travelling plane of blade edges of the cutting blades and a surface of an embedding block. <P>SOLUTION: A sensor 20 detects a position of a surface of the embedding block B when a stage 12 moves to a Z direction by a moving means and an embedding block B blocks a laser beam L so that a light receiving section 22 has come not to receive the laser beam L. A beam diaphragm 25 for narrowing a beam diameter of the laser beam L emitted from a light projecting section 21 is placed between the light projecting section 21 and the embedding block B. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic slicing apparatus.

2. Description of the Related Art Conventionally, a microtome (automatic slicing device) is generally known as a device for producing a sliced piece sample used for physics and chemistry experiments and microscopic observation. The thin slice specimen is obtained by fixing a thin slice having a thickness of several μm (for example, 3 μm to 5 μm) on a substrate such as a slide glass. The thin slice is prepared by slicing an embedding block in which a biological sample is embedded with an embedding agent into the above-described thickness. The embedded block is prepared by replacing a biological sample taken out of a human body or a laboratory animal and fixed in formalin with paraffin, and then solidifying the periphery with paraffin to produce a block.
In order to obtain a thin slice by the automatic slicing device, first, the embedding block is set on the stage of the automatic slicing device, and rough cutting is performed to cut the thickness to about 10 μm with a cutting blade. By this rough cutting, the surface of the embedding block is smoothed, and the embedded biological sample that is the object of the experiment or observation is exposed on the surface (hereinafter referred to as surface exposure). After the rough cutting is finished, main cutting is performed by slicing the embedded block to a thickness of 3 μm to 5 μm to obtain a thin slice to be a thin slice specimen.

  By the way, in order to obtain a thin slice with a uniform thickness from the above-mentioned embedding block, first, the embossing block is obtained by slicing irregularities and inclined surfaces formed on the surface layer portion of the embedding block in the above-described roughing process. Therefore, it is necessary to smooth the surface of the surface and perform the surface projection. In order to perform the chamfering of the embedding block, first, the relative position between the surface layer of the embedding cassette set on the stage and the cutting edge of the cutting blade of the microtome is adjusted. When the relative position between the cutting edge and the surface of the embedding block is determined, the surface of the embedding block is sliced by reciprocating the cutting edge along the surface of the stage. The Thereafter, with the cutting blade operated, the stage is gradually raised to continuously perform thin cutting, and the surface of the embedding block can be smoothed to perform chamfering.

  Moreover, when chamfering the embedding block, the relative position between the surface layer of the embedding cassette and the running surface of the cutting edge of the cutting blade is important. If the surface layer of the embedding cassette and the running surface of the cutting edge of the cutting blade wrap too much, the thin slice to be sliced becomes thick and the biological sample may be cut along with a desired cross section. On the other hand, if the cutting blade is operated from a position where the relative position between the surface layer of the embedding block and the running surface of the cutting edge of the cutting blade is too far away, the cutting blade will remain idle for a long time, and the surface of the embedding block will be thinly cut. Since it takes a long time to be performed, there is a problem that work efficiency is poor.

Therefore, in Patent Document 1, for example, an embedding block is placed on a tiltable stage, and a reference surface supported via a load cell is pressed against the sample surface of the embedding block. A configuration is disclosed in which the sample surface is held in a state parallel to the reference surface.
Further, for example, in Patent Document 2, a line sensor having a light receiving unit and a light projecting unit is provided, and the amount of light shielded by the embedding block is calculated from the change in the amount of laser light received by the light receiving unit. A configuration for detecting the position (height and inclination angle) is disclosed.
Japanese Patent No. 3565005 JP 2008-76251 A

  However, the configuration of Patent Document 1 described above is unsanitary because the reference surface is directly pressed against the sample surface of the embedding block. Moreover, there is a possibility that the biological sample embedded in the embedding block may be affected. Specifically, there is a possibility that paraffin loss or destruction in which the biological sample is embedded or tissue block of the biological sample may be caused by pressing the embedded block.

10 and 11 are explanatory diagrams showing a conventional method for detecting the position of an embedded block using a line sensor as in Patent Document 2 described above, and FIG. 10 is a case where the surface layer portion of the embedded block is a flat surface. FIG. 11 shows a case having an inclined surface.
As shown in FIG. 10, when the surface layer portion of the embedding block 100 is a flat surface, the laser light emitted from the light projecting unit 101 of the sensor when the sensor and the embedding block are brought closer to each other. L ′ is partially shielded by the surface layer portion of the embedding block 100. As a result, the light amount (beam width) D1 of the laser light L ′ emitted from the light projecting unit 101 and the light amount D2 of the laser light L ′ received by the light receiving unit 102 of the sensor change (D1> D2). As a result, the position of the embedding block 100 can be detected, and the relative position between the embedding block 100 and a cutting blade (not shown) can be adjusted.
On the other hand, as shown in FIG. 11, for example, when the inclined surface 103 is formed on the surface layer portion of the embedding block 100 ′, the laser light L ′ incident on the surface layer portion of the embedding block 100 ′ Reflected by the inclined surface 103 without being shielded by '. The light receiving unit 102 receives the laser light that has traveled straight from the light projecting unit 101 and the laser light reflected by the inclined surface 103. As a result, there is little change between the light amount D1 ′ of the laser light L ′ emitted from the light projecting unit 101 and the light amount D2 ′ of the laser light L ′ received by the light receiving unit 102 of the sensor. Since it cannot be detected, the exact height of the embedding block 100 ′ cannot be detected, and the embedding block 100 ′ cannot be stopped at a predetermined position.

  That is, in the configuration of Patent Document 2, there is a possibility that the laser beam reflected on the surface of the embedding block may be received by the light receiving unit, and the exact shielding amount shielded by the embedding block cannot be detected. There is a problem that an error occurs between the shielding amount and the detected shielding amount. In addition, since the line sensor has a relatively wide laser width, it cannot detect a minute change in the amount of light, and the accuracy of the height adjustment of the embedded block is insufficient.

  Therefore, the present invention has been made in view of such circumstances, and is good by accurately and quickly adjusting the relative position between the running surface of the cutting edge of the cutting blade and the surface layer of the embedding block. Provided is an automatic slicing device that can take out a thin slice and improve the working efficiency by reducing the idle time of the cutting blade.

In order to solve the above problems, the present invention provides the following means.
An automatic slicing device according to the present invention is an automatic slicing device for slicing an embedded block in which a biological sample is embedded, and a stage having a mounting surface parallel to an XY plane on which the embedded block is mounted. A cutting blade that travels along the XY plane and slices the surface layer of the embedding block in parallel with the XY plane; and a moving unit that moves the stage in the Z direction orthogonal to the XY plane; A sensor for detecting the position of the surface of the embedding block in the Z direction, the sensor emitting a laser beam along the XY plane, and the embedding in the optical path of the laser beam And a light receiving portion that receives the laser light emitted from the light projecting portion, and the sensor moves the stage in the Z direction by the moving means, and Bro When the laser beam is shielded and the light receiving unit stops receiving the laser beam, the position of the surface of the embedded block is detected, and the gap between the light projecting unit and the embedded block is detected. A beam stop for reducing the beam diameter of the laser light emitted from the light projecting unit is disposed.

According to this configuration, the beam diameter emitted from the light projecting unit can be reduced by disposing the beam stop for reducing the beam diameter of the laser light emitted from the light projecting unit between the light projecting unit and the embedding block. Can be small. That is, laser light is used as the light emitted from the light projecting unit, and a beam stop is disposed to reduce the beam diameter so that the light with the small laser diameter passes through the surface of the embedding block. Become. Therefore, when the embedding block is moved by the moving means and the embedding block is interposed between the light projecting unit and the light receiving unit, the laser beam is immediately shielded. Can be detected.
This makes it possible to detect the position of the embedding block without touching the embedding block, unlike the conventional case, thereby preventing the loss or destruction of the embedding agent in which the biological sample is embedded and the tissue collapse of the biological sample. be able to.
In addition, since the beam diameter is smaller than the conventional configuration using a line sensor, the laser beam can be shielded almost simultaneously when the embedded block crosses the laser beam. As a result, reception of reflected light reflected on the surface of the embedding block can be suppressed, and the top portion of the surface layer portion of the XY plane of the embedding block can be detected with high accuracy. Can be small.
Therefore, since the relative position between the running surface of the cutting edge of the cutting blade and the surface layer of the embedding block can be adjusted accurately and quickly, a thin slice of uniform thickness can be obtained from the beginning of cutting, and cutting It is possible to improve the working efficiency by shortening the blade swing time.

Further, in the automatic slicing device according to the present invention, the beam diameter of the laser light when passing through the central portion on the surface in the Z direction of the embedded block is set to 50 μm or more and 1000 μm or less. It is said.
Setting the beam diameter to less than 50 μm is not preferable because in addition to the effect that the diffraction of the laser beam spreads at the beam stop, the amount of received light may be reduced and affected by disturbance light. On the other hand, when the beam diameter is set to be larger than 1000 μm, when the laser beam is received by the light receiving unit, as described above, the laser beam reflected by the surface of the embedding block is large, and the light amount of the laser beam detected by the light receiving unit is very small. It is not preferable because it cannot detect a change.
On the other hand, by setting the beam diameter when passing through the central portion of the surface in the Z direction to the embedded block to 50 μm or more and 1000 μm or less, it is possible to suppress the diffraction of the laser beam and Therefore, when the embedded block is interposed between the light projecting unit and the light receiving unit, the laser beam is immediately shielded. At this point, the position of the embedded block is Can be detected. Therefore, it becomes possible to detect the surface position of the embedding block with high accuracy.

In the automatic slicing device according to the present invention, the embedding block is formed in a rectangular shape when viewed from the Z direction, and the light projecting unit and the light receiving unit are sandwiched between the embedding blocks. It is characterized by being arranged on an extension of a diagonal line on the surface in the Z direction of the buried block.
When the surface of the embedding block is uniformly inclined, the top is located at the corner (the end of the diagonal line). Then, the top part of an embedding block can be detected reliably by arrange | positioning a light projection part and a light-receiving part on the extended line of the diagonal in the Z direction surface of an embedding block. In addition, the position in the Z direction on a line that combines not only one direction (for example, the X direction) but also another direction (for example, the Y direction) orthogonal to one direction in the surface layer portion of the embedded block can be detected. The top of the embedded block in the surface layer portion in the Z direction can be detected with high accuracy. Therefore, the position adjustment of the embedding block can be performed with high accuracy.

Moreover, the automatic slicing device according to the present invention is characterized in that the pair of sensors are arranged on a pair of diagonal lines on the surface in the Z direction of the embedding block.
According to this configuration, the height of the top of the embedding block can be detected more reliably by arranging the pair of sensors on each pair of extension lines on the surface in the Z direction of the embedding block. A thin slice with a uniform thickness can be obtained, and a highly accurate surface can be obtained.

Further, in the automatic slicing device according to the present invention, a divergence angle limiting diaphragm for regulating a divergence angle of the laser beam received by the light receiving unit is disposed between the light receiving unit and the embedded block. It is characterized by that.
According to this configuration, even when the divergence angle of the laser beam is expanded by the diffusion of the laser beam or the reflection on the surface of the embedding block, only the laser beam in a predetermined range can be supplied to the light receiving unit. Therefore, erroneous detection of laser light can be reliably prevented. As a result, the position of the embedded block can be detected with higher accuracy.

In the automatic slicing device according to the present invention, the sensor is in an ON state in a state where the light receiving unit receives the laser light, while the embedded block shields the laser light and receives the light. The moving means first moves the stage from a reference position to a first position where the sensor is turned off, and then moves the stage. The sensor is moved from the first position to a second position where the sensor is turned on between the reference position and the first position, and then the stage is moved from the second position to the second position and the second position. The stage is moved to a target position where the sensor is in an OFF state with respect to the first position, and the moving speed of the stage between the second position and the target position is between the reference position and the first position. Of the above Is characterized in that it is set slower than the moving speed of the over-di.
By the way, in order to reliably detect the moment when the laser beam is shielded by reducing the beam diameter, the stage must be moved at a relatively low speed. Therefore, it may take time to adjust the position of the embedded block.
On the other hand, according to the configuration of the present invention, first, the stage is moved at a relatively high speed to the first position where the sensor crosses the optical path of the laser beam and the sensor is turned off, and then the sensor is turned on again. The position of the stage is once returned to the second position. Thereby, the stage and the cutting blade can be relatively moved at a relatively high speed from the reference position to the second position close to the target position.
Thereafter, the stage is relatively moved at a relatively low speed from the second position to the target position where the sensor is again turned off. As a result, since the section where the stage is moved at a relatively low speed is a section between the second position and the target position, the stage is relatively moved compared to the case where the entire section from the reference position to the target position is moved at a low speed. The section moved at low speed can be shortened. Therefore, even if the beam diameter is reduced, the position of the embedded block can be adjusted accurately and quickly.

According to the automatic slicing device according to the present invention, by disposing a beam stop for reducing the beam diameter of the laser light emitted from the light projecting unit between the light projecting unit and the embedding block, from the light projecting unit. The diameter of the emitted beam can be reduced. That is, laser light is used as the light emitted from the light projecting unit, and a beam stop is disposed to reduce the beam diameter so that the light with the small laser diameter passes through the surface of the embedding block. Become. Therefore, when the embedding block is moved by the moving means and the embedding block is interposed between the light projecting unit and the light receiving unit, the laser beam is immediately shielded. Can be detected.
This makes it possible to detect the position of the embedding block without touching the embedding block, unlike the conventional case, thereby preventing the loss or destruction of the embedding agent in which the biological sample is embedded and the tissue collapse of the biological sample. be able to.
In addition, since the beam diameter is smaller than the conventional configuration using a line sensor, the laser beam can be shielded almost simultaneously when the embedded block crosses the laser beam. As a result, reception of reflected light reflected on the surface of the embedding block can be suppressed, and the top portion of the surface layer portion of the XY plane of the embedding block can be detected with high accuracy. Can be small.
Therefore, since the relative position between the running surface of the cutting edge of the cutting blade and the surface layer of the embedding block can be adjusted accurately and quickly, a thin slice of uniform thickness can be obtained from the beginning of cutting, and cutting It is possible to improve the working efficiency by shortening the blade swing time.

Next, embodiments of the present invention will be described with reference to the drawings.
(Automatic slicing device)
FIG. 1 is a perspective view showing an embedding block.
As shown in FIG. 1, the automatic slicing apparatus 10 (see FIG. 2) slices an embedded block B in which a biological sample S is embedded with an embedding agent N with a predetermined rake angle (see FIG. 2). For example, it is an apparatus that smoothes the surface of the embedding block B by slicing it to about 10 μm and exposes an embedded biological sample that is an object of experiment or observation to the surface. Thus, by cutting the embedded block B with the rake angle θ attached, the cutting resistance can be reduced and smoother cutting can be performed.

  The embedding block B is obtained by substituting the water in the formalin-fixed biological sample S with paraffin, and further solidifying the periphery in a block shape (cuboid shape) with an embedding agent N such as paraffin. As a result, the biological sample S is embedded in paraffin. In addition, the biological sample S is, for example, a tissue such as an organ extracted from a human body, a laboratory animal, or the like, and is appropriately selected in the medical field, the pharmaceutical field, the food field, the biological field, or the like. In the present embodiment, the embedding block B is described as being fixed on a cassette K formed in a box shape.

2 and 3 are schematic configuration diagrams of the automatic slicer, FIG. 2 is a side view, and FIG. 3 is a plan view.
As shown in FIGS. 2 and 3, the automatic slicing apparatus 10 according to the present embodiment has a stage 12 having a placement surface 11 on which the cassette K to which the embedding block B is fixed is placed parallel to the horizontal plane (XY plane). A cutting blade 13 for cutting the surface layer portion of the embedding block B, a moving means (not shown) such as a piezoelectric element for relatively moving the stage 12 in the Z direction orthogonal to the mounting surface 11 of the stage 12, and the Z direction 2 includes a sensor 20 that detects the position (height) of the embedding block B and a control unit (not shown) that comprehensively controls the automatic slicing device 10.

  The stage 12 is configured to be movable in the Z direction by the operation of the moving means controlled by the control unit, and the upper surface thereof constitutes a placement surface 11 on which the cassette K is placed. The mounting surface 11 is configured so that the surface direction thereof coincides with the horizontal direction (XY plane), and the cassette K can be held horizontally with the embedding block B facing upward. Therefore, by adjusting the height of the stage 12 (Z direction), the thickness of the thin slice sliced by the cutting blade 13 can be adjusted. The stage 12 shown in FIGS. 2 and 3 is located at the lower end position in the Z direction, that is, the initial position (reference position) of the stage 12. The stage 12 is a multi-axis stage 12 in which the rotation about the Z axis and the inclination about the X axis and the Y axis can be freely adjusted, and the posture of the embedding block B can be freely adjusted. It is possible to control and set the direction and inclination of the embedding block B to a desired state.

  The cutting blade 13 is a long magnetic cutting blade 13 whose one end is a cutting edge 13a, and has a predetermined rake angle with respect to an XY plane parallel to the mounting surface 11 obliquely above the stage 12. Arranged in a state. Specifically, it is located above the stage 12 in the initial position in the Z direction and on the side of the stage 12 in the X direction on the XY plane. Moreover, the cutting blade 13 extends in a direction in which the longitudinal direction intersects one side of the surface in the Z direction of the stage 12 (embedded block B).

  The cutting blade 13 is configured to be able to reciprocate in a state (a direction along the short direction of the cutting blade 13) at a predetermined angle with respect to the X axis on the XY plane by a driving means (not shown) such as a motor. (See arrow in FIG. 3). At this time, during the reciprocating movement of the cutting blade 13, the cutting edge 13 a of the cutting blade 13 travels in parallel with the surface direction (XY plane) of the mounting surface 11 of the stage 12. It is a running surface of the blade edge 13a. That is, the traveling surface of the blade edge 13a is parallel to the surface direction of the mounting surface 11, and when the surface layer of the embedding block B exists on the traveling surface of the blade edge 13, the embedding placed on the mounting surface 11 is performed. The block B is sliced parallel to the XY plane. At this time, since it extends in a direction intersecting with the longitudinal direction of the cutting blade 13 and one side along the Y direction of the stage 12, the cutting edge enters from the corner of the XY plane of the embedding block B at the time of cutting. It has become.

  The stage 12 described above incorporates a moving means such as a piezoelectric element (not shown) therein, and is height-controlled so as to rise by a certain amount in the vertical Z direction when a voltage is applied. At this time, the stage 12 is controlled to rise by a certain amount (for example, about 10 μm) every time the cutting blade 13 reciprocates once. As a result, the embedding block B moves upward in the Z direction as the cutting blade 13 moves, and is cut by the cutting blade 13. At this time, since the height is controlled by the stage 12, the surface is sliced to a predetermined thickness. The surface layer portion of the embedding block B can be sliced one after another by the reciprocating movement of the cutting blade 13 and the rising of the stage 12 synchronized with the reciprocating movement. The moving means may be constituted by a motor or the like.

  Here, the sensor 20 is disposed in a state that is offset downward from the traveling surface of the cutting blade 13 in the Z direction by a predetermined distance, and a light projecting unit 21 that emits the laser light L along the XY plane, and the Z direction. A light receiving unit 22 that receives the laser light L emitted from the light projecting unit 21 is disposed on the optical path of the laser light L with the embedded block B interposed therebetween. That is, the light projecting unit 21 and the light receiving unit 22 are disposed between the cutting blade 13 and the mounting surface 11 of the stage 12 at the initial position in the Z direction, and sandwich the mounting surface 11 in plan view. Is arranged. Specifically, the light projecting unit 21 and the light receiving unit 22 are arranged on diagonal lines on the surface in the Z direction of the embedding block B with the placement surface 11 in between.

  Therefore, the laser light L emitted from the light projecting unit 21 is configured to pass on a diagonal line on the surface in the Z direction of the embedding block B. The sensor 20 is in an ON state in a state where the laser light L emitted from the light projecting unit 21 is received by the light receiving unit 22, while the laser light L is shielded by the embedding block B, and the light receiving unit 22 is laser light. In a state where L is not received, the OFF state is set, and the position of the surface of the embedding block B in the Z direction is detected. As the laser emitted from the light projecting unit 21, a laser composed of an infrared laser having a relatively small beam diameter and a small divergence angle is preferably used.

  A beam stop 25 is disposed on the exit end side on the optical path of the laser light L, that is, between the light projecting unit 21 and the stage 12 in plan view. The beam stop 25 is for reducing the beam diameter of the laser light L emitted from the light projecting unit 21, and includes a shielding plate 25 a that shields the laser light L, and a laser light emitted from the light projecting unit 21. It is composed of a minute opening 25b through which L passes.

  In the beam stop 25, the laser beam L is preferably reduced so that the beam diameter D when passing through the central portion (intersection of diagonal lines) of the surface of the embedded block B in the Z direction is 50 μm or more and 1000 μm or less. If the beam diameter D is less than 50 μm, in addition to the effect that the diffraction of the laser beam L spreads in the opening 25b, the amount of received light may be reduced and affected by disturbance light, which is not preferable. On the other hand, when the beam diameter D is larger than 1000 μm, when the laser beam L is received by the light receiving unit 22, the laser beam reflected by the surface of the embedding block B is large as described above, and the divergence angle (radiation angle) of the laser beam L is large. ) Is enlarged, and a minute change in the light amount of the laser light L detected by the light receiving unit 22 cannot be detected. On the other hand, by setting the beam diameter when passing through the central portion of the surface in the Z direction of the embedded block B to 50 μm or more and 1000 μm or less, diffraction of the laser beam L can be suppressed, and the embedded block Since the detection of the reflected light on the surface of B can be prevented, the laser light L is immediately shielded when the embedded block B is interposed between the light projecting unit 21 and the light receiving unit 22. At the time, the surface position of the embedded block B can be detected.

  On the other hand, a divergence angle limiting diaphragm 26 is disposed on the incident end side on the optical path of the laser light L, that is, between the light receiving unit 22 and the stage 12 in plan view. The divergence angle limiting diaphragm 26 is configured to reduce the beam diameter of the laser light L to be equal to the above-described beam diameter before the laser light L emitted from the light projecting unit 21 is received by the light receiving unit 22. The divergence angle limiting diaphragm 26 includes a shielding plate 26a that shields the laser light L and a minute opening 26b through which the laser light L passes. Thus, in order to adjust the beam diameter as described above when entering the embedding block B and when receiving light to the light receiving unit 22, the laser divergence angle, beam diameter, envelope, It can be adjusted by setting parameters such as the distance between the light projecting unit 21 and the light receiving unit 22 from the center of the buried block B, the positions of the beam diaphragm 25 and the divergence angle limiting diaphragm 26, and the diameters of the openings 25b and 26b. .

(Embedded block height detection method)
Next, an embedded block height detection method (stage height adjustment method) will be described. FIG. 4 is a flowchart showing a method for detecting the height of an embedded block. 5-7 is explanatory drawing which shows the position detection method of an embedding block.
As shown in FIGS. 2 and 4, first, in step S <b> 1, the high-speed search of the stage 12 is started in a state where the cassette K in which the embedding block B is fixed is placed on the placement surface 11 of the stage 12. Specifically, the moving means is actuated by an instruction from the control unit to raise the stage 12 from the initial position upward in the Z direction at a high speed. The “high speed” in step S1 is a speed that is about 2 to 5 times faster than the ascending speed of the stage 12 during a low-speed search described later.

  Next, in step S2, it is determined whether or not the sensor 20 is in an ON state. The ON state of the sensor 20 is a state where the laser light L emitted from the light projecting unit 21 is detected by the light receiving unit 22. On the other hand, the OFF state of the sensor 20 means that the stage 12 is raised and the embedding block B vertically crosses the optical path of the laser light L emitted from the light projecting unit 21, thereby shielding the laser light L and receiving it. In this state, the laser beam L cannot be detected by the unit 22. That is, it is determined whether or not the embedding block B protrudes upward in the Z direction from the XY plane that is the passage surface of the laser light L.

When the determination result in step S2 is “YES”, that is, when the laser beam L is not shielded by the embedding block B, the surface layer portion of the embedding block B is from the XY plane that becomes the passage surface of the laser beam L. Judged to be below in the Z direction. In this case, the stage 12 is continuously raised in the Z direction, and the flow of step S2 is repeated until the embedding block B crosses the laser beam L.
On the other hand, when the determination result in step S2 is “NO”, that is, as shown in FIG. 5, the embedded block B crosses the laser beam L and shields the laser beam L so that the embedded block B It is determined that the projection protrudes upward in the Z direction from the XY plane serving as a passage surface of the. Then, the process proceeds to step S3.

  Next, in step S3, the moving means is stopped by an instruction from the control unit to stop the high speed search of the stage 12. At this time, the embedding block B is at the highest upper end position (second position) in the Z direction. Note that this upper end position is a position where the stage 12 has stopped after the OFF state is detected by the sensor 20 during the high-speed search. Specifically, the XY plane in which the embedding block B serves as the passage surface of the laser beam L. It is a position protruding about 0.5 mm from the top in the Z direction.

  In step S4, the moving means is restarted by an instruction from the control unit, and the stage 12 is again lowered by a predetermined amount in the Z direction from the upper end position (see FIG. 5). Specifically, as shown in FIG. 6, when the amount of protrusion from the XY plane, which is the surface through which the laser beam L of the embedded block B passes, is about 0.5 mm, the stage 12 is moved about 1 mm from the upper end position. Lower in the direction. Thereby, the laser beam L emitted from the light projecting unit 21 reaches the light receiving unit 22 again, and the sensor 20 is turned on again. Note that the position in the Z direction of the stage 12 at this time is a lowered position (second position) between the initial position (see FIG. 2) and the upper end position (see FIG. 5).

  Next, in step S5, a low-speed search of the stage 12 is started by an instruction from the control unit. Specifically, as shown in FIG. 7, the moving means is operated to move the stage 12 again upward in the Z direction from the above-described lowered position (see FIG. 6). The low speed search is preferably suppressed to about 1/2 to 1/5 of the rising speed in the high speed search in step S1 described above.

  Next, in step S6, as in step S2 described above, it is determined whether or not the sensor is in an ON state.

  By the way, the surface layer portion of the embedding block B before performing chamfering (rough cutting) may have irregularities and inclined surfaces, and it is difficult to detect the top portion of the surface layer portion of the embedding block. Specifically, as shown in FIG. 11, when the inclined surface 103 is formed on the surface layer portion of the thin-cut embedding block 100 ′, the laser light L ′ incident on the surface layer portion of the embedding block 100 ′ Reflected by the inclined surface 103 without being shielded by the buried block 100 ′. As the laser light L ′ received by the light receiving unit 102, the laser light traveling straight from the light projecting unit 101 and the laser light reflected by the inclined surface 103 are received. As a result, there is little change between the light amount D1 ′ of the laser light L ′ emitted from the light projecting unit 101 and the light amounts D2 and ′ of the laser light L ′ received by the light receiving unit 102 of the sensor, and the change in the accurate light amount is small. Therefore, the exact height of the embedding block 100 ′ cannot be detected, and the embedding block 100 ′ cannot be stopped at a predetermined position.

8 and 9 are explanatory views showing the relationship between the embedding block and the sensor, FIG. 8 shows a case where the surface layer portion of the embedding block is a flat surface, and FIG. 9 shows a case where it has an inclined surface. .
As shown in FIG. 8, when the surface layer portion of the embedding block B is a flat surface, when the stage 12 (see FIG. 2) is raised, the laser light L emitted from the light projecting unit 21 of the sensor 20. Is shielded by the surface layer portion of the embedding block B. Thereby, the laser beam L is not detected by the light receiving unit 22 by the light receiving unit 22, and the sensor 20 is turned off.

  On the other hand, as shown in FIG. 9, when the inclined surface 50 is formed on the surface layer portion of the embedding block B, the stage 12 rises and the top 50a of the inclined surface 50 of the embedding block B is the light of the laser beam L. I'm on the street. Thereby, the laser beam is shielded by the top 50a. On the other hand, when the inclined surface 50 enters the optical path of the laser light L, the laser light L is reflected by the inclined surface 50, so that the divergence angle of the laser light L is expanded. At this time, since the divergence angle limiting diaphragm 26 is disposed between the light receiving unit 22 and the embedding block B, the laser light L reflected by the inclined surface 50 is shielded by the shielding plate 26 a and goes to the light receiving unit 22. It has been blocked from reaching. That is, only the laser beam L having a small divergence angle linearly traveling from the light projecting unit 21 is incident on the light receiving unit 22. Therefore, when the laser beam L is blocked by the top 50a, the laser beam is blocked and the sensor 20 is turned off.

When the determination result in step S6 is “YES”, that is, when the laser beam L is not shielded by the embedded block B, the surface layer portion of the embedded block B is on the XY plane that becomes the passage surface of the laser beam L. It is determined that it is below in the Z direction. In this case, the stage 12 is continuously raised at a low speed, and the flow of step S6 is repeated until the embedding block B crosses the laser beam L.
On the other hand, when the determination result in step S6 is “NO”, that is, the embedded block B crosses the laser beam L and shields the laser beam L so that the surface layer portion of the embedded block B It is determined that it has reached the XY plane. Then, the process proceeds to step S7.

In step S7, the moving means is stopped by an instruction from the control unit to stop the low speed search of the stage 12. Thereby, the stage 12 can be stopped at the target position.
Finally, in step S8, the stage 12 is moved by the gap between the sensor 20 and the cutting blade 13. That is, as described above, the XY plane serving as the traveling surface of the cutting edge 13a of the cutting blade 13 and the XY plane serving as the passing surface of the laser light L are offset in advance in the Z direction by a predetermined distance. The position where the height is raised is the cutting position of the embedding block B. In addition, it is preferable to set the cutting position of this embodiment below the Z direction about 30 micrometers from the running surface of the blade edge | tip 13a. When the cutting position is made to coincide with the traveling surface of the blade edge 13a, when an error occurs in the height adjustment of the stage 12, the thin slice to be sliced at the first reciprocation (start of cutting) becomes thick and has a desired cross section. There is a risk of cutting. On the other hand, if the cutting start position is set to a position that is too far away from the running surface of the blade edge 13a, it takes a long time for the cutting blade 13 to be idle for a long time until the surface layer of the embedding block B is sliced. On the other hand, the cutting start position is set about 30 μm below the running surface of the blade edge 13a, so that the surface layer portion of the embedding block B is moved after the cutting blade 13 is reciprocated about 3 times (about 3 times of air vibration). Start slicing. Thereby, while being able to start thin cutting reliably from the top part 50a of the embedding block B, while suppressing the thickness of a thin slice at the start of cutting, the time to start cutting can be shortened.

As described above, in this embodiment, the beam stop 25 that restricts the beam diameter of the laser light L emitted from the light projecting unit 21 is disposed between the light projecting unit 21 and the embedding block B.
According to this configuration, the beam stop 25 that restricts the beam diameter of the laser light L emitted from the light projecting unit 21 of the sensor 20 is disposed between the light projecting unit 21 and the embedding block B. The diameter of the beam emitted from the portion 21 can be reduced. That is, the laser beam is used as the light emitted from the light projecting unit 21, and the beam aperture 25 is disposed to reduce the beam diameter, so that the focused light having a small laser diameter passes through the surface of the embedding block B. It will be. Therefore, when the height of the embedding block B is adjusted, the laser light L is immediately shielded when the embedding block B is interposed between the light projecting unit 21 and the light receiving unit 22. The position of the embedding block B can be detected. Thereby, unlike the conventional case, the position of the embedding block B can be detected without touching the embedding block B. Therefore, the defect or destruction of the embedding agent N in which the biological sample S is embedded, the tissue of the biological sample Collapse can be prevented.
Further, since the beam diameter is smaller than that of the conventional configuration using the line sensor, the laser beam L can be shielded almost simultaneously when the embedded block B crosses the laser beam. Thereby, while being able to suppress the reception of the reflected light reflected on the surface (for example, inclined surface 50) of the embedding block B, detecting the top part in the surface layer part of the XY plane of the embedding block B with high precision. Therefore, the detection error by the sensor 20 can be reduced.
Accordingly, since the relative position between the running surface of the cutting edge 13a of the cutting blade 13 and the surface layer of the embedding block B can be adjusted accurately and quickly, a thin slice having a uniform thickness can be obtained from the beginning of cutting. , High-precision surface measurement becomes possible. In addition, the idle time of the cutting blade 13 can be shortened to improve work efficiency.

  Further, since the divergence angle limiting diaphragm 26 that restricts the divergence angle of the laser beam L received by the light receiving unit 22 is disposed, the diffusion of the laser beam L and the surface of the embedding block B (for example, the inclined surface 50) are arranged. Even when the divergence angle of the laser beam L is increased by reflection, only the laser beam L in a predetermined range can be supplied to the light receiving unit 26. Therefore, erroneous detection of the laser light L can be reliably prevented. Thereby, the position detection of the embedding block B can be performed with higher accuracy.

  By the way, when the surface of the embedding block B inclines uniformly, the top part 50a is located in a corner | angular part (end part of a diagonal). Therefore, by arranging the light projecting unit 21 and the light receiving unit 22 on the extension of the diagonal line in the XY plane of the embedding block B, the top 50a of the embedding block B can be reliably detected. In addition, the position in the Z direction on a line that combines not only one direction (for example, the X direction) but also another direction (for example, the Y direction) orthogonal to one direction in the surface layer portion of the embedded block B can be detected. Therefore, the top part (for example, top part 50a) in the surface layer part of the XY plane of the embedding block B can be detected with high accuracy. Therefore, the position adjustment of the embedding block B can be performed with high accuracy.

Further, in order to reliably detect the moment when the laser beam is shielded by reducing the beam diameter, the stage and the cutting blade must be relatively moved at a relatively low speed. Therefore, it may take time to adjust the position of the embedded block.
On the other hand, according to the present embodiment, first, the stage 12 is moved at a relatively high speed (high speed search) to the upper end position where the sensor crosses the optical path of the laser light L and the sensor is in the OFF state, and then the sensor again. The stage 12 is once returned to the lowered position where becomes ON. Thereby, the stage 12 and the cutting blade 13 can be moved at a relatively high speed to a lowered position where the stage 12 and the cutting blade 13 are brought closer to each other than the initial position.
Thereafter, the stage 12 is moved at a relatively low speed from the lowered position to the target position where the sensor 20 is again turned off. As a result, the section in which the low speed search is performed is a section between the descending position and the target position, and therefore the section in which the stage 12 is moved at a relatively low speed as compared with the case where the section from the initial position to the target position is moved at a low speed. Can be shortened. Therefore, even when the beam diameter is reduced, the position adjustment of the embedded block B can be performed accurately and quickly.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, a configuration has been described in which a pair of sensors including a light projecting unit and a light receiving unit are arranged on one diagonal line in the XY plane with an embedding block interposed therebetween. It is also possible to employ a configuration in which a pair of sensors is used to arrange the embedded blocks on a pair of diagonal lines in the XY plane. Thereby, since the height of the top part of the embedding block can be detected more reliably, a thin slice with a more uniform thickness can be obtained, and a highly accurate surface can be obtained.

In the above-described embodiment, the stage is adjusted at a high speed by raising the stage at a high speed to a position where the embedding block crosses the laser beam, and returning to the lower end position. Not limited to this, the stage height may be adjusted when the stage is lowered. That is, the stage can be lowered at a low speed from the upper end position where the laser beam is shielded, and the position where the detection of the laser beam is started again by the light receiving unit can be determined as the target position of the stage.
Moreover, although the above-mentioned embodiment demonstrated the case where the embedding block B was mainly rough-cut, it is applicable also when performing the main cutting which slices the embedding block B to the thickness of 3 micrometers-5 micrometers very thinly. It is.

It is a perspective view which shows an embedding block by the automatic slicing apparatus in embodiment of this invention. It is a schematic block diagram of the automatic slicing device in embodiment of this invention. It is a schematic block diagram of the automatic slicing device in embodiment of this invention. It is a flowchart which shows the position detection method of the embedding block in embodiment of this invention. It is a schematic block diagram of the automatic slicing device equivalent to FIG. 3, and is explanatory drawing which shows the position detection method of the embedding block. It is a schematic block diagram of the automatic slicing device equivalent to FIG. 3, and is explanatory drawing which shows the position detection method of the embedding block. It is a schematic block diagram of the automatic slicing device equivalent to FIG. 3, and is explanatory drawing which shows the position detection method of the embedding block. It is explanatory drawing which shows the relationship between the embedding block and a sensor in case the surface layer part of an embedding block is a flat surface. It is explanatory drawing which shows the relationship between the embedding block and a sensor in case the surface layer part of an embedding block has an inclined surface. It is explanatory drawing which shows the position detection method of the conventional embedding block using the line sensor in case the surface layer part of an embedding block is a flat surface. It is explanatory drawing which shows the position detection method of the conventional embedding block using the line sensor in case the surface layer part of an embedding block has an inclined surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Automatic slicing device 11 ... Mounting surface 12 ... Stage 13 ... Cutting blade 20 ... Sensor 21 ... Light emission part 22 ... Light-receiving part 25 ... Beam aperture 26 ... Divergence angle restriction aperture B ... Embedded block L ... Laser beam N … Embedding agent S… biological sample

Claims (6)

In an automatic slicing device for slicing an embedded block in which a biological sample is embedded,
A stage having a placement surface parallel to the XY plane on which the embedding block is placed;
A cutting blade that runs along the XY plane and slices the surface layer of the embedding block in parallel with the XY plane;
Moving means for moving the stage in a Z direction orthogonal to the XY plane;
A sensor for detecting the position of the surface of the embedding block in the Z direction,
The sensor is arranged with a light projecting unit that emits laser light along the XY plane, and the laser light that is arranged on the optical path of the laser light with the embedding block interposed therebetween and emitted from the light projecting unit. A light receiving portion for receiving light,
The sensor includes the embedded block when the stage is moved in the Z direction by the moving unit, the embedded block shields the laser light, and the light receiving unit stops receiving the laser light. Detect the position of the surface of the
An automatic slicing device, wherein a beam stop for reducing a beam diameter of the laser light emitted from the light projecting unit is disposed between the light projecting unit and the embedding block.   2. The automatic slicing device according to claim 1, wherein a beam diameter of the laser light when passing through a central portion of the surface in the Z direction of the embedded block is set to 50 μm or more and 1000 μm or less. The embedded block is formed in a rectangular shape when viewed from the Z direction,
The said light projecting part and the said light-receiving part are arrange | positioned on the extended line of the diagonal line in the surface of the said Z direction of the said embedding block on both sides of the said embedding block. 2. The automatic slicing device according to 2.   4. The automatic slicing apparatus according to claim 3, wherein the pair of sensors are arranged on a pair of diagonal lines on the surface in the Z direction of the embedding block.   5. A divergence angle limiting diaphragm for restricting a divergence angle of the laser beam received by the light receiving unit is disposed between the light receiving unit and the embedded block. The automatic slicer according to any one of the above. The sensor is in an ON state when the light receiving unit is receiving the laser light, while the embedded block is blocking the laser light and the light receiving unit is not receiving the laser light. It becomes OFF state
The moving means is
First, the stage is moved from a reference position to a first position where the sensor is in an OFF state,
Next, the stage is moved from the first position to a second position where the sensor is in an ON state between the reference position and the first position,
Next, the stage is moved from the second position to a target position where the sensor is in an OFF state between the second position and the first position,
The moving speed of the stage from the second position to the target position is set slower than the moving speed of the stage from the reference position to the first position. The automatic slicing device according to any one of claims 5 to 6.

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