JP2009025362A - Microscope image capturing apparatus and microscope system - Google Patents

Abstract

【Task】
Conventionally, the resolution of the microscope optical system and the resolution of the image sensor do not necessarily match, so that the optical performance of the microscope optical system cannot be fully utilized, the image quality of the observation image is deteriorated, or unnecessary pixels are read out to read out time. There was a problem such as becoming longer.
[Solution]
In the present invention, an image sensor composed of pixels arranged in a two-dimensional matrix that converts light imaged by a microscope optical system into an image signal, and an enlargement / reduction controller that reads an image signal of a desired pixel from the image sensor A microscope image capturing apparatus comprising: a camera processing unit that converts an image signal read from the image sensor by the enlargement / reduction control unit into digital image data; and a display unit that displays an observation image processed by the camera processing unit In the above, a matching adjustment unit is provided that varies the resolution of the observation image read from the image sensor by the enlargement / reduction control unit according to the optical resolution of the microscope optical system.
[Selection] Figure 1

Description

  The present invention relates to a microscope image pickup apparatus and a microscope system that take a microscope image by performing enlargement or reduction.

  2. Description of the Related Art Conventionally, in an image capturing apparatus that captures an image using an image sensor, a partial readout unit (hereinafter referred to as ROI) selects an arbitrary area from all pixel areas of the image sensor and reads out pixel signals of the selected area. It is like that. Further, the thinning-out reading unit reads out image signals of arbitrary pixels from all the pixels of the image pickup device, and reads out every other pixel, for example. Such partial reading means and thinning-out reading means have been used to increase the frame rate of an image to be displayed because there are fewer image signals to be read than all pixels.

Further, in a microscope system for enlarging and reducing an observation image, an optical zoom unit using an optical system having a zoom lens that can move back and forth along the optical axis, and an electronic zoom unit that controls an image signal by a control circuit It was supposed to be realized by. A zoom motor for moving the zoom lens back and forth and a motor drive circuit for driving the zoom motor are connected to the optical zoom means, and the zoom lens is moved back and forth along the optical axis by the rotation of the zoom motor. By moving, the focal length of the optical system is changed. For example, if the focal length of the optical system is increased, the enlargement operation is performed, and if the optical system is shortened, the reduction operation is performed. The electronic zoom means is realized by an electronic zoom means connected to an output terminal of an amplifier that amplifies an image signal output from the image sensor, and an electronic zoom control circuit that controls the electronic zoom means. The magnification is selected and the image is enlarged or reduced (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 03-141327

  However, the ROI and the thinning-out reading means according to the above-described conventional technique are techniques for imaging an arbitrary area and increasing the frame rate for displaying an image. For this reason, in order to perform the enlargement operation, it is necessary to perform the image signal read from the image sensor only with the electronic zoom means, and there is a problem that the image quality deteriorates.

  In addition, when zooming in or out using an optical zoom unit, the image quality is less degraded than that of an electronic zoom unit, but the resolution of the microscope optical system changes depending on the zoom position, so it does not necessarily match the resolution of the image sensor. There was a problem of not doing. For example, when the resolution of the microscope optical system is higher than the resolution of the image sensor, the performance of the microscope optical system cannot be fully utilized, and a sample image can be taken only with a low resolution. Conversely, when the resolution of the imaging device is higher than the resolution of the microscope optical system, an image signal of a pixel that is not necessary is read out, and there is a problem that it takes time to read out.

  An object of the present invention is to match the resolution of a microscope optical system and an image sensor, and to use a ROI or a thinning readout method as a means for enlarging or reducing an observation image. It is an object of the present invention to provide a microscope image capturing apparatus and a microscope system capable of enlarging or reducing an observation image without deterioration.

  A microscope image pickup apparatus according to the present invention includes an image pickup element including pixels arranged in a two-dimensional matrix that converts light imaged by a microscope optical system into an image signal, and an image signal of a desired pixel from the image pickup element. A read control unit, an image processing unit that converts an image signal read from the image sensor by the read control unit into digital image data, a display unit that displays an observation image processed by the image processing unit, and the microscope According to another aspect of the present invention, there is provided a matching adjustment unit that changes a method of reading an observation image read from the image sensor according to an optical resolution of the optical system.

In particular, the matching adjustment unit defines the pixel pitch d [m] (d is a natural number) of the image sensor using the optical resolution limit value δ [m] (δ is a real number) of the microscope optical system by the following equation. ,
d ≒ 1/2 ・ δ
The number of pixels p [pixel] (p is a natural number) of the image sensor is defined by the following equation using the pixel pitch d and the imaging area φ [m] of the microscope optical system,
p ≒ (φ / √2) / d
An integer value obtained by rounding down the decimal point of the number of pixels p obtained by the above equation is used as the number of pixels of the observation image read out from the image sensor by the readout control unit.

  The microscope optical system further includes a zoom optical system and a zoom magnification detection unit that detects a magnification of the zoom optical system, and the matching adjustment unit is configured to detect the magnification of the zoom optical system detected by the zoom magnification detection unit. The optical resolution of the microscope optical system corresponding to is obtained, and the resolution of the observation image read from the image sensor is varied by the readout control unit according to the optical resolution of the microscope optical system.

  Further, a pixel shifting mechanism for shifting an incident position of light incident on the image sensor from the microscope optical system is further provided, and the matching adjustment unit is configured such that an image area size of the image sensor is equal to or larger than an observation area size of the microscope optical system. When the pixel pitch of the image sensor is larger than the resolution of the microscope optical system, the pixel shift operation is performed a plurality of times using the pixel shift mechanism according to the optical resolution of the microscope optical system, and the readout control is performed. The unit generates an observation image by combining a plurality of images read from the image sensor for each of the plurality of pixel shifting operations.

  In particular, the pixel shifting mechanism is configured by a mechanism for tilting a parallel plate glass disposed between the microscope optical system and the imaging device.

  Alternatively, a mirror reflector moving mechanism that reflects light incident from the microscope optical system and changes a position incident on the image sensor is further provided, and the matching adjustment unit includes the optical resolution of the microscope optical system and the image sensor. When the imaging area size of the imaging device is smaller than the observation area size of the microscope optical system, the observation area of the microscope optical system is divided into a plurality of regions using the mirror reflector moving mechanism. The reading control unit may generate an observation image by combining a plurality of images read from the image sensor divided into the plurality of regions.

  In particular, the enlargement / reduction processing unit does not read out all pixels of the image sensor.

  In the microscope system according to the present invention, in the microscope system including the microscope optical system in the microscope image capturing apparatus, the microscope optical system includes an objective lens and an imaging lens, and forms an image of a specimen. An image optical system is used, and the image pickup device picks up an image of the sample as a subject.

  In the present invention, an enlarged / reduced image with little deterioration in image quality can be obtained even when the observation image is enlarged or reduced using an ROI or thinning readout means. Also, even when performing an enlargement or reduction operation using the optical zoom means, the image signal is read from the image sensor so that the resolution of the observation image is optimized according to the change in the resolution of the microscope optical system depending on the zoom position. The readout time is short, and an observation image without image quality deterioration can be obtained even if enlargement or reduction is performed.

Hereinafter, embodiments of a microscope image pickup apparatus and a microscope system according to the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram of a microscope system 100 according to the first embodiment. The microscope system 100 includes a microscope optical system (microscope) 101 and a microscope image capturing apparatus 102.

  The microscope 101 includes a first objective lens 152, a second objective lens 153, an imaging lens (projection lens) 154, and a microscope control unit 155 from the specimen (subject) 151 side. Light incident from the specimen 151 is guided to the imaging lens 154 via the first objective lens 152 and the second objective lens 153, and the imaging lens 154 connects the specimen image to the imaging element 103 of the microscope image imaging apparatus 102. Image. Further, the microscope control unit 155 outputs the limit value of the optical resolution of the microscope 101 to the MPU 105. The limit value of the optical resolution will be described in detail later.

  The microscope image capturing apparatus 102 includes an image sensor 103, an image processing unit 104, an MPU (microprocessor) 105, a system bus 106, an image memory 107, a display unit 108, an operation unit 109, and an enlargement / reduction control unit. 110.

  The light imaged on the light receiving surface of the image sensor 103 by the imaging lens 154 of the microscope 101 is converted into an image signal and output to the image processing unit 104. At this time, the enlargement / reduction processing unit 110 selects a pixel to be read from the image sensor 103 to the image processing unit 104. For example, based on a command from the MPU 105, image signals are read from every pixel of the image sensor 103 arranged in a two-dimensional matrix every other pixel, or an image signal in a predetermined area in the image area of the image sensor 103 is read. read out.

  The image processing unit 104 performs gain control and noise removal of the image signal read from the image sensor 103, performs A / D conversion to digital image data, performs color correction, and outputs the result to the MPU 105. The MPU 105 stores the image data received from the image processing unit 104 as an observation image in the image memory 107 via the system bus 106. At the same time, an observation image is displayed on the display unit 108 via the system bus 106.

  The operation unit 109 is provided with a zoom button or the like, and gives an instruction to the MPU 105 to enlarge or reduce the observation image displayed on the display unit 108.

  Next, the relationship between the imaging area of the imaging device 103 in the microscope system 100 and the image area (effective area) of the microscope 101 will be described. Here, for the sake of easy understanding, as shown in FIG. 2, the imaging area 251 of the imaging device 103 of the microscope image imaging apparatus 102 is square, and the imaging area 251 is inscribed in the circular image area 252 of the microscope 101. The case of arranging will be described. In FIG. 2, for example, if φ = 20 [mm] as the diameter of the image area 252 of the general microscope 101, the length of one side necessary for the image sensor 103 is φ / √2 [mm] = 14. 14 [mm]. On the other hand, since the pixel pitch of a general 5M class (2560 × 1920) pixel image sensor is about 3.4 [μm], the diameter of a circle circumscribing the imaging area 253 of the 5M class image sensor is about 10 [mm]. Thus, the diameter of the image area 202 of the microscope 101 is significantly smaller than 20 [mm]. Next, the pixel pitch (resolution) and the number of pixels of the image sensor 103 necessary when the diameter φ of the image area of the microscope 101 is 20 mm will be described.

  The limit value δ [m] of the optical resolution of the microscope 101 in the microscope system 100 is expressed by (Expression 1) using the wavelength λ [m] of light and the numerical aperture (NA) of the second objective lens of the microscope. .

δ = 0.61 · (λ / NA) (Formula 1)
Here, when λ = 0.55 μm and NA = 0.05, δ = 6.71 μm from (Equation 1).
At this time, the pixel pitch d [m] (d is a natural number) necessary for the image sensor 103 is obtained by (Expression 2).

d ≒ 1/2 · δ (Formula 2)
Here, if the pixel pitch d satisfies d ≦ 1/2 · δ, the resolution of the observation image photographed by the image sensor 103 is equal to or higher than the optical resolution of the microscope 101. It is preferable that the pixel pitch d is a value in the vicinity of (1/2 · δ) as shown in Equation 2). In the above example, since δ = 6.71 μm, the pixel pitch d is 3.36 μm. However, for easy understanding, the pixel pitch d is 3 μm in this embodiment.

  On the other hand, as described with reference to FIG. 2, when the diameter φ of the image area of the microscope 101 is 20 mm, the number of pixels p (pixel) of the image sensor 103 is obtained by (Expression 3).

p = (φ / √2) / d (Formula 3)
When d = 3 μm and φ = 20 mm are substituted, the number of pixels p required by the image sensor 103 is p = 4714 (pixel) when an integer value obtained by rounding down the decimal point is taken. This corresponds to a 22 Mpixel class image sensor, and is a size that allows a sufficient observation of the diameter φ20 mm of the image area of the microscope 101. Moreover, since the resolution of the image sensor 103 is higher than the limit value of the optical resolution of the microscope 101, the optical performance of the microscope 101 can be sufficiently reproduced.

  As described above, in the microscope system 100 according to the present embodiment, the imaging element 103 in which the optical resolution of the microscope 101 and the resolution of the imaging element 103 of the microscope image imaging apparatus 102 are substantially equal is used.

  Next, the enlargement / reduction operation of the microscope image pickup apparatus 102 will be described. As described above, since the optical resolution of the microscope 101 and the resolution of the image pickup device 103 of the microscope image pickup apparatus 102 are substantially equal, the observation image is enlarged by the pixel of the region to be enlarged of the image pickup device 103. This can be realized by reading out the image signal of ROI. On the contrary, the reduction of the observation image can be realized by performing thinning readout from all the pixels of the image sensor 103. This is shown in FIG. Note that the resolution of the display unit 108 is 471 × 471 [pixel]. The imaging area 401 of the imaging device 103 has 4714 × 4714 [pixel], and has a resolution equivalent to the optical resolution of the microscope 101.

  In FIG. 3, when the entire specimen image 402 projected on the imaging area 401 is displayed on the display unit 108, it is read out to 1/10 from all pixels (4714 × 4714 [pixel]) of the imaging element 103. By reducing the size, it is possible to display an observation image having a resolution that matches the resolution (471 × 471 [pixel]) of the display unit 108. Conversely, when the portion indicated by the dotted line 403 of the sample image 402 projected on the imaging area 401 is enlarged, the portion indicated by the dotted line 403 of the portion to be enlarged from all the pixels (4714 × 4714 [pixel]) of the imaging element 103 is indicated. By performing ROI readout of the pixel image signal, the observation image can be enlarged and displayed at a resolution that matches the resolution (471 × 471 [pixel]) of the display unit 108.

  As described above, since the optical resolution of the microscope 101 and the resolution of the image sensor 103 of the microscope image capturing apparatus 102 are substantially equal, the image quality of the observation image enlarged and displayed on the display unit 108 does not deteriorate.

Next, processing of the entire microscope system 100 in the first embodiment will be described using the flowcharts of FIGS. 4 and 5. 4 and 5 are operated by a program stored in advance in the MPU 105. First, a matching logic process for matching the optical resolution of the microscope 101 of the microscope system 100 according to the present embodiment with the resolution of the observation image read from the imaging element 103 of the microscope image imaging apparatus 102 will be described using the flowchart of FIG. To do.
(Step S201) The matching logic processing of the microscope system 100 is started.
(Step S202) The MPU 105 reads the resolution δ1 of the image sensor 103. The value of the resolution δ1 may be stored in the MPU memory at the time of manufacture.
(Step S203) The MPU 105 reads the limit value δ2 of the optical resolution of the microscope 101 from the microscope control unit 155.
(Step S204) The MPU 105 reads the resolution of the display unit.
(Step S205) The MPU 105 compares the resolution δ1 of the image sensor 103 with the limit value δ2 of the optical resolution of the microscope 101. If δ1≈δ2, the process proceeds to step S207, and if δ1 <δ2, the process proceeds to step S206. As described above, the image sensor 103 used in the microscope system 100 has a resolution substantially equal to the minimum optical resolution limit value that can be used in the microscope 101. Therefore, there is no case where δ1> δ2. Further, δ1 <δ2 is large when the second objective lens of the microscope 101 is replaced, or when the optical zoom lens as described in the second embodiment is used. This is the case.
(Step S206) The MPU 105 resets the resolution δ1 of the image sensor 103 with the resolution when the thinning readout is performed at a predetermined thinning rate (initial thinning rate) so that δ1≈δ2. For example, in the case of δ1 = 3 μm and δ2 = 9 μm, the resolution of 9 μm when the thinning readout is performed at the thinning rate of 1/3 is reset as δ1. In order to improve the sensitivity, the number of binning pixels to be combined into one pixel by combining image signals of a plurality of pixels may be set. For example, in the case of δ1 = 3 μm and δ2 = 9 μm, the number of binning pixels is 9 pixels of 3 pixels in the vertical direction and 3 pixels in the horizontal direction.
(Step S207) The MPU 105 determines whether enlargement is instructed by the zoom button of the operation unit 109 or reduction is instructed. In the case of enlargement, the process proceeds to step S208. In the case of reduction, the process proceeds to step S209.
(Step S <b> 208) The MPU 105 instructs the enlargement / reduction control unit 110 according to the enlargement magnification instructed by the operation unit 109 to partially read (ROI) a portion to be enlarged from the image sensor 103. When δ1 is reset in step S206, partial reading is performed by thinning out the enlarged portion at the initial thinning rate obtained in step S206 so that image signals of unnecessary pixels are not read out.
(Step S209) The MPU 105 instructs the enlargement / reduction control unit 110 according to the reduction magnification instructed by the operation unit 109, and reads out the portion to be reduced from the image sensor 103. If δ1 is reset in step S206, reading is performed by further thinning out the portion to be reduced at the initial thinning rate obtained in step S206 so that image signals of unnecessary pixels are not read out.
(Step S210) The MPU 105 delivers the image signal read from the image sensor 103 to a display system process for displaying the image signal on the display unit 108 as an observation image.
(Step S211) The MPU 105 determines whether or not the user has set to save the observation image using the operation unit 109, and proceeds to step S212 if it is to be saved, and proceeds to step S213 if it is not to be saved.
(Step S212) The MPU 105 stores the image signal read from the image sensor 103 in the image memory 107 via the system bus 106 as an observation image.
(Step S213) The matching logic process is terminated and the process proceeds to a display process.
(Step S214) The matching logic process is terminated.

  In step S211, the process of storing the observation image in the image memory 107 and the process of shifting to the display system are branched, but the process is stored in the image memory 107 and the display system process described below is performed. It doesn't matter if you do.

Next, processing of the display system of the microscope system 100 according to the present embodiment will be described using the flowchart of FIG.
(Step S215) The processing of the display system of the microscope system 100 is started.
(Step S216) The number of vertical and horizontal pixels of the observation image read from the image sensor 103 is read.
(Step S217) The number of vertical and horizontal pixels on the display screen of the display unit 108 is read.
(Step S218) The number of vertical and horizontal pixels of the observation image read from the image sensor 103 is compared with the number of vertical and horizontal pixels of the display screen of the display unit 108. If the number of pixels is not equal, the process proceeds to step S219. If the number of pixels is equal, the process proceeds to step S220.
(Step S219) The vertical and horizontal pixel numbers of the observation image read from the image sensor 103 are adjusted so as to be equal to the vertical and horizontal pixel numbers of the display screen of the display unit 108. Here, it is assumed that the number of vertical and horizontal pixels of the display screen of the display unit 108 is equal to or less than the number of vertical and horizontal pixels of the observation image read from the image sensor 103.
(Step S220) An observation image is displayed on the display screen of the display unit.
(Step S221) The processing of the display system is terminated.
In the matching logic processing described with reference to FIG. 4, the maximum value of the number of pixels of the image signal read from the image sensor 103 may be limited in advance by the number of pixels on the display screen of the display unit 108.

  As described above, the microscope system 100 according to the present embodiment is set so that the optical resolution of the microscope 101 and the resolution of the image sensor 103 of the microscope image capturing apparatus 102 are substantially equal to each other. Even when the image is enlarged, the quality of the displayed observation image does not deteriorate.

In addition, since only the image signals of necessary pixels are read from the image sensor 103 in accordance with the number of pixels on the display screen of the display unit 108, it is possible to perform high-speed processing without useless reading time.
(Second Embodiment)
Next, a microscope system 100b according to the second embodiment will be described. FIG. 6 is a block diagram of the microscope system 100b. The microscope system 100b includes a microscope optical system (microscope) 101b and a microscope image capturing device 102b.

  The microscope 101b differs from the microscope 101 of FIG. 1 of the first embodiment in that an optical zoom lens 156 is provided. 1 denote the same components as those in FIG. The microscope control unit 155 changes the zoom position of the optical zoom lens 156 according to a command from the MPU 105 of the microscope image pickup apparatus 102b, and informs the MPU 105 of the current zoom position. As described above, in the present embodiment, the optical zoom lens 156 enlarges and reduces the specimen image formed on the imaging element 103 of the microscope image imaging apparatus 102b from the specimen 151.

  In the microscope image pickup apparatus 102b, when the user operates the optical zoom button of the operation unit 109 to give an instruction for zooming in or zooming out, the MPU 105 issues a command to the microscope control unit 155 of the microscope 101b and the optical zoom lens 156. Move the zoom position to the zoom in or zoom out side.

  Here, the relationship between the optical zoom lens and the optical resolution will be described. In general, when the zoom of the optical zoom lens is changed, the limit value of the optical resolution of the microscope 101b is also changed. For example, the numerical aperture when the second objective lens is viewed from the light receiving surface of the image sensor 103 is larger when zoomed out and reduced than when zoomed in and zoomed in. The resolution limit value δ is smaller when zoomed out and reduced than when zoomed in and enlarged.

  As described above, the MPU 105 of the microscope image capturing apparatus 102b can know the limit value δ of the optical resolution of the microscope 101b based on the zoom position of the optical zoom lens 156 input from the microscope control unit 155. If the limit value δ of the optical resolution of the microscope 101b is known, the pixel pitch d necessary for the observation image taken by the image sensor 103 can be obtained from (Equation 2) described in the first embodiment. Furthermore, when the pixel pitch d is obtained, the number of pixels p of the image sensor 103 is obtained from (Equation 3) described in the first embodiment.

  The pixel pitch d required for the observation image photographed by the image sensor 103 in the present embodiment is set to be approximately equal to the limit value of the optical resolution of the microscope 101b when zoomed out to the maximum. Therefore, even when zoomed in, the resolution of the imaging element 103 of the microscope image pickup apparatus 102 does not become smaller than the limit value of the optical resolution of the microscope 101b, so that the optical performance of the microscope 101b can always be sufficiently reproduced. .

  Next, an operation when the optical zoom lens 156 of the microscope 101b captures an image of the specimen 151 at an arbitrary zoom position will be described. When the optical zoom lens 156 of the microscope 101b is stopped at an arbitrary zoom position, the MPU 105 captures the zoom position from the microscope control unit 155. The limit value of the optical resolution of the microscope 101b is obtained from the captured zoom position, and the number of thinned pixels of the image signal read from the image sensor 103 is obtained. For example, if the limit value of the optical resolution of the microscope 101b at an arbitrary zoom position is ½ of the limit value of the optical resolution of the microscope 101b when zoomed out to the maximum, the imaging element 103 The number of pixels to be thinned out to be read is also halved. Here, since the limit value of the optical resolution of the microscope 101b at an arbitrary zoom position is halved, the resolution of the observation image hardly changes even when all the pixels are read from the image sensor 103, and the area is 4 Since it is doubled, it takes four times the readout time by simple calculation.

As described above, the microscope system 100b according to the present embodiment makes the optical resolution of the microscope 101b substantially equal to the resolution of the observation image read from the image sensor 103 of the microscope image capturing apparatus 102b. Similarly, the image quality of the observation image enlarged and displayed on the display unit 108 does not deteriorate. In addition, since the optimum number of pixels to be thinned out of the image signal read from the image sensor 103 is obtained according to the zoom position of the optical zoom lens 156 of the microscope 101b, it is not necessary to read out the image signal of unnecessary pixels, and the reading time is reduced. Can be shortened.
(Third embodiment)
Next, a microscope system 100c according to the third embodiment will be described. FIG. 7 is a block diagram of the microscope system 100c. The microscope system 100c includes a microscope optical system (microscope) 101c and a microscope image capturing device 102c.

  The microscope 101c differs from the microscope 101b of FIG. 6 of the second embodiment in that a parallel flat glass 157 and a pixel shift control unit 158 are provided. The imaging device 103c of the microscopic image capturing apparatus 102c of this embodiment has the same imaging area size as the imaging device 103 of the first and second embodiments, but has a pixel pitch of 1/2 and a resolution of A low one is used. 6 denote the same components as those in FIG. The parallel flat glass 157 is disposed between the imaging lens 154 and the image sensor 103c. Further, the pixel shift control unit 158 changes the inclination of the parallel flat glass 157 back and forth and left and right in accordance with a command from the MPU 105 of the microscope image capturing apparatus 102c.

  If the parallel flat glass 157 has a certain inclination θ with respect to the optical axis, the refraction action when the light enters the glass and the refraction action when the light exits the glass cause the light in the optical axis direction. It is known that the incident position and the outgoing position are deviated. That is, by tilting the parallel flat glass 157 with respect to the optical axis in the four directions of front, rear, left and right of the image sensor 103c, the position of the sample image formed on the image sensor 103c by the imaging lens 154 is on the image sensor 103c. It will be shifted back and forth and left and right.

  Next, the optical resolution of the microscope 101c and the resolution of the image sensor 103c of the microscope image capturing apparatus 102c will be described. As described above, the image pickup device 103c of the microscope image pickup apparatus 102c of the present embodiment has the same image pickup area size as the image pickup device 103 of the first and second embodiments, but the pixel pitch is 1. Therefore, if the sample image is taken as it is, the optical performance of the microscope 101c cannot be sufficiently reproduced.

  For example, FIG. 8A is a diagram depicting 8 × 8 pixels at a pixel pitch that provides a resolution substantially equal to the optical resolution of the microscope 101c. However, since the image pickup element 103c of the microscope image pickup apparatus 102c of the present embodiment has a pixel pitch of ½, for example, the pixels A1, B1, C1, and D1 are picked up as one pixel, so A1 and B1 The information of the pixels C1 and D1 cannot be separated, and the image quality of the observation image is deteriorated due to the optical resolution of the microscope 101c.

  Therefore, in this embodiment, the 8 × 8 pixel image signal in FIG. 8A is read in four steps. For example, the first time is centered on the pixels A1, A2, A3, and A4 as shown in FIG. 8B, and the second time is centered on the pixels B1, B2, B3, and B4 as shown in FIG. 8C. The third time is centered on the pixels C1, C2, C3, and C4 as shown in FIG. 8D, and the fourth time is centered on the pixels D1, D2, D3, and D4 as shown in FIG. 8E. Read each. Here, the reading position is changed by the pixel shift control unit 158 changing the inclination of the parallel flat glass 157 in accordance with the command from the MPU 105 as described above. In addition, since the pixel pitch of the image sensor 103c is coarse, for example, when the image is taken centering on the pixel D1, information on peripheral pixels (A1, B1, A3, C3, A4, B2, A2, C1) of the pixel D1 is also obtained. Although slightly included, by performing image processing such as difference and differentiation, the resolution of the observation image can be increased in a pseudo manner.

As described above, the microscope system 100c according to the present embodiment can substantially equalize the optical resolution of the microscope 101c and the resolution of the observation image read from the image sensor 103c of the microscope image capturing apparatus 102c. Similar to the embodiment, the image quality of the observation image enlarged and displayed on the display unit 108 hardly deteriorates. In addition, since the imaging element 103c can use components having a resolution lower than the optical resolution of the microscope 101c, the cost can be reduced compared to the first and second embodiments.
(Fourth embodiment)
Next, a microscope system 100d according to the fourth embodiment will be described. FIG. 9 is a block diagram of the microscope system 100d. The microscope system 100d includes a microscope optical system (microscope) 101d and a microscope image capturing device 102d.

  The microscope 101d is different from the microscope 101b of FIG. 6 of the second embodiment in that a reflection mirror 159 and a mirror control unit 160 are provided. In addition, the image pickup device 103d of the microscope image pickup apparatus 102d of the present embodiment is the same as the image pickup device 103 of the first and second embodiments but has a pixel pitch of ¼. is doing. 6 denote the same components as those in FIG. The reflection mirror 159 is disposed between the imaging lens 154 and the image sensor 103d. Further, the mirror control unit 160 moves the reflection mirror 159 in accordance with a command from the MPU 105 of the microscope image capturing apparatus 102d, and changes the position projected on the image sensor 103d.

  The optical resolution of the microscope 101d and the resolution of the imaging device 103d of the microscope image pickup apparatus 102d are almost equal, and the optical performance of the microscope 101c can be sufficiently reproduced. However, the size of the imaging area of the imaging device 103d is microscopic. Since there is only a quarter of the image area of the scope 101d, the entire image area cannot be photographed. This is shown in FIG. In FIG. 10A, the imaging area 302 of the imaging device 103d can only capture a part of the image area 301 of the microscope 101d.

  Therefore, in this embodiment, the image area 301 of the microscope 101d in FIG. For example, the first time is taken in the upper left of the image area 301 as shown in FIG. 10B, the second time is taken in the upper right of the image area 301 as shown in FIG. 10C, and the third time is shown in FIG. As shown in d), the lower left of the image area 301 is photographed, and the fourth time, the lower right of the image area 301 is photographed as shown in FIG. Here, as described above, the shooting position of the image area 301 is changed by the mirror control unit 160 moving the reflection mirror 159 back and forth and right and left in accordance with an instruction from the MPU 105. It should be noted that the images shot in four steps are combined at each shooting position and stored in the image memory 107 as one sample image.

  Thus, in the microscope system 100d according to the present embodiment, the optical resolution of the microscope 101d and the resolution of an observation image that is captured and combined multiple times with the imaging element 103d of the microscope image imaging device 102d are substantially equal. Therefore, as in the first and second embodiments, the image quality of the observation image enlarged and displayed on the display unit 108 based on the combined observation image is hardly deteriorated. In addition, the imaging element 103d has a resolution that is substantially equal to the optical resolution of the microscope 101d, but can use parts with an imaging area smaller than the image area, so that the cost can be reduced compared to the first and second embodiments. Can be achieved.

1 is a block diagram of a microscope system 100 according to a first embodiment. 3 is an explanatory diagram illustrating a relationship between an imaging area of an imaging element 103 and an image area of a microscope 101. FIG. It is explanatory drawing which shows the expansion / contraction operation | movement of the microscope image imaging device. It is a flowchart which shows a matching logic process. It is a flowchart which shows the process of a display system. It is a block diagram of the microscope system 100b which concerns on 2nd Embodiment. It is a block diagram of the microscope system 100c which concerns on 3rd Embodiment. 8 is an explanatory diagram for explaining an operation of a pixel shift control unit 158. FIG. It is a block diagram of microscope system 100d concerning a 4th embodiment. 6 is an explanatory diagram for explaining an operation of a mirror control unit 160. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Microscope system 101 ... Microscope 102 ... Microscope image pick-up device 103 ... Imaging element 104 ... Image processing part 105 ... MPU
106: System bus 107 ... Image memory 108 ... Display unit 109 ... Operation unit 110 ... Enlargement / reduction control unit 151 ... Sample 152 ... First objective lens 153 ... First 2 objective lens 154 ... imaging lens

Claims (8)

An image sensor comprising pixels arranged in a two-dimensional matrix for converting light imaged by a microscope optical system into an image signal;
A read control unit that reads out an image signal of a desired pixel from the image sensor;
An image processing unit that converts an image signal read from the image sensor by the read control unit into digital image data;
A display unit for displaying an observation image processed by the image processing unit;
A microscope image pickup apparatus, comprising: a matching adjustment unit that changes a method of reading an observation image read from the image pickup device according to an optical resolution of the microscope optical system. In the microscope image pickup device according to claim 1,
The matching adjustment unit
The pixel pitch d [m] (d is a natural number) of the image sensor is defined by the following equation using the optical resolution limit value δ [m] (δ is a real number) of the microscope optical system,
d ≒ 1/2 ・ δ
The number of pixels p [pixel] (p is a natural number) of the image sensor is defined by the following equation using the pixel pitch d and the imaging area φ [m] of the microscope optical system,
p ≒ (φ / √2) / d
A microscope image capturing apparatus, wherein an integer value obtained by rounding down the decimal point of the number of pixels p obtained by the above equation is used as the number of pixels of an observation image read out from the image sensor by the readout control unit. In the microscope image pickup device according to claim 1 or 2,
The microscope optical system further includes a zoom optical system, and a zoom magnification detector that detects the magnification of the zoom optical system,
The matching adjustment unit obtains the optical resolution of the microscope optical system corresponding to the magnification of the zoom optical system detected by the zoom magnification detection unit, and the read control unit determines the optical resolution of the microscope optical system according to the optical resolution of the microscope optical system. A microscope image pickup device characterized in that the resolution of an observation image read out from an image pickup device is varied. In the microscope image pickup device according to any one of claims 1 to 3,
A pixel shifting mechanism for shifting the incident position of light incident on the image sensor from the microscope optical system;
The matching adjustment unit, when the imaging area size of the imaging element is equal to or larger than the observation area size of the microscope optical system and the pixel pitch of the imaging element is larger than the resolution of the microscope optical system, the optical resolution of the microscope optical system In response to the above, a plurality of pixel shifting operations are performed using the pixel shifting mechanism,
The reading control unit generates an observation image by combining a plurality of images read from the imaging element for each of the plurality of pixel shifting operations. In the microscope image pickup device according to claim 4,
The said pixel shift mechanism is comprised by the mechanism which inclines the parallel plate glass arrange | positioned between the said microscope optical system and the said image pick-up element. The microscope image imaging device characterized by the above-mentioned. In the microscope image pickup device according to any one of claims 1 to 3,
A mirror reflector moving mechanism that reflects light incident from the microscope optical system and changes a position incident on the image sensor;
The matching adjustment unit, when the optical resolution of the microscope optical system is equal to the pixel pitch of the imaging element and the imaging area size of the imaging element is less than the observation area size of the microscope optical system, Dividing the observation area of the microscope optical system into a plurality of regions using a plate moving mechanism,
The reading control unit generates an observation image by combining a plurality of images read out from the imaging element in the plurality of regions. In the microscope image pickup device according to any one of claims 1 to 6,
The magnification / reduction processing unit does not read out all the pixels of the imaging device, and the microscope image imaging device. In the microscope system including the microscope optical system in the microscope image pickup device according to any one of claims 1 to 7,
The microscope optical system includes an objective lens and an imaging lens, and is composed of an imaging optical system that forms an image of a specimen.
The microscope system, wherein the imaging device captures an image of the specimen as a subject.

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