JP4222759B2 - Magnification imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus for imaging a minute specimen that generates excitation light having different wavelengths in accordance with light in a plurality of different wavelength regions and converting it into an electrical signal.
[0002]
[Prior art]
In a color image reading apparatus such as an image scanner, three color filters that can be switched are arranged to perform color separation with a color filter placed in an optical path between an imaging lens and an image sensor. Here, when a color image is read, the image is read by switching among three color filters that can be switched.
[0003]
In the prior art, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-32214, the thickness of a photoelectric conversion chip-like color filter is changed in a color image sensor to adjust the optical path length for each color. In this way, a countermeasure against chromatic aberration is known. However, this method may be available when the wavelength of the light source is limited, but it is inconvenient when the wavelength must be changed according to the target subject. In the case of a linear sensor, since a filter is formed for each line, this forming process requires about 3 to 4 processes. However, when trying to apply such a method for adjusting the filter thickness for each color to a two-dimensional sensor, for example, arranging the filters in a zigzag arrangement for each pixel is a placement process for the number of pixels. The process takes a very long time, becomes a fine process, and is hardly practical. Therefore, it is necessary to perform adjustment so that chromatic aberration does not occur in the lens system placed in front of the area image sensor.
[0004]
[Problems to be solved by the invention]
However, a technique for eliminating chromatic aberration by designing a combination of a plurality of lenses having different refractive indexes in such a lens system has a complicated structure and a high cost.
[0005]
In addition, since the lens system placed in front of such an image sensor constitutes an objective lens, the image sensor unit and the lens can be interchanged for use with different magnifications depending on the type of subject. It needs to be configured and is inferior in cost. Furthermore, if a switching filter is configured in the lens system (lens unit), it is fatal in terms of cost and it is difficult to ensure light shielding. On the other hand, when the illuminance of the subject is sufficient to some extent as in a normal optical camera, it is possible to increase the depth of focus that is allowable for the optical focus position error by narrowing the luminous flux from the subject, When an image pickup device with a magnifying optical system such as this device is used to precisely pick up an object with a weak light amount, the aperture depth cannot be used, so the depth of focus becomes extremely small, and it is essential to adjust the focus position for each light receiving wavelength range. is there. In addition, since the size of the specimen that is the subject is very small (micron order), if the focal length remains deviated depending on each wavelength region, an accurate outline of the specimen cannot be grasped in the imaging data.
[0006]
In addition, in an ordinary optical camera, there is a configuration in which an infrared cut filter is inserted between the image sensor and the lens unit, but two filters are configured in a relatively large area (at least the area of the image sensor). The volume of the filter structure increases because it must be slid and switched. If the actuator is not shielded from light, the light shielding property in the gap between the filter members will be deteriorated. Furthermore, if a filter is placed on the subject side of the light source's irradiation surface, the irradiation light will be scattered and stray light received at the filter edge, etc., and even a very weak light will be imaged. .
[0007]
The present invention provides an imaging apparatus capable of adjusting a different optical path length in a wavelength region with a simple mechanism in imaging weak excitation light from a subject having a plurality of different wavelength regions.
[0008]
[Means for Solving the Problems]
For this reason, the present invention is an image pickup apparatus that picks up an image of a minute subject that emits light at a wavelength different from the wavelength of the irradiated light according to the irradiated light in at least two wavelength regions, and converts the image into an electrical signal. A stage, light source means for illuminating a surface on which the subject is loaded, light switching means for switching irradiation light emitted from the light source means to light beams of a plurality of different wavelength regions, and light beams of the plurality of different wavelength regions Lens means for condensing light from the subject irradiated by the image sensor, an image sensor for converting the two-dimensional image light collected by the lens means into an electrical signal, and the illumination light of the lens means and the light source means Two or more filter means arranged in the optical path between the light emitting position and the light switching means by the light switching means, and the two or more filters At least one of the stages Place on top of By switching the wavelength region of the irradiation light. Arise In response to changes in the focal length of the lens means The focal position coincides with the light receiving surface of the image sensor. An enlargement imaging apparatus comprising: an optical path length adjusting means for adjusting an optical path length between the stage and the image sensor.
[0009]
With the above configuration, the magnifying imaging apparatus according to the present invention can adjust the optical path length that is different in the wavelength region with a simple mechanism even when imaging weak excitation light from a subject having a plurality of different wavelength regions. The light from the subject with different wavelengths is adjusted to an appropriate optical path by using different light sources, and a sharp image that is not blurred is acquired even when imaging with severe depth of focus is performed due to the magnification imaging device. Made it possible. .
[0010]
The magnifying image pickup device further includes a moving unit that supports the two or more filter units and moves the filter unit in a direction intersecting a light receiving direction of the lens unit. The two or more filter means are made of materials having different thicknesses or different refractive indexes.
[0012]
The light source means of the present invention includes at least two or more rod-shaped light beam means, and the light beam means includes a light emitting element that emits a specific wavelength and a light converging means that converges light from the light emitting element. It has the structure which irradiates a light beam from the other end different from the end which installed the said light emitting element of this light means.
[0013]
When the irradiation light of at least two wavelength regions is composed of irradiation light of two wavelength regions of ultraviolet light and green light, the optical path length adjusting means is a filter means corresponding to the green light irradiation light. It is placed on top of each other .
[0014]
by this, The two Different wavelength regions Received the irradiation light In imaging weak excitation light from a subject, the optical path lengths that differ in the wavelength region can be adjusted with a simple mechanism.
[0015]
Here, the lens means is arranged so that its optical axis coincides with an orthogonal line passing through the upper surface of the central portion of the stage, and has a connection portion that can be switched or replaced by an enlargement system that enlarges the size of the subject. Further, the optical path length adjusting means can be replaced.
[0017]
Here, the exposure time controlled by the exposure control means is 0.2 seconds or more.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Prior to describing the details of the imaging apparatus, a technical background relating to a sample to be imaged by the imaging apparatus will be described.
(1) Technical background of the imaging device
In the imaging apparatus, a resin receptor is prepared in the membrane part of the membrane kit including the specimen to be counted. In addition to this, there are film-type film kits as sample collection kits, but such kit forms will be developed more in the future. Since the illuminance of the light emitted from the bacteria to be imaged is extremely low, it cannot be understood unless the exposure is increased by performing continuous exposure for a certain period of time.
[0019]
However, since the resin color of the receptor is not a perfect black body, the level increases with the image of bacteria. As a result, the contrast between the background portion and the bacterial portion in the finally acquired entire image has a very low S / N. Therefore, if the subsequent image processing is performed without imposing a burden, a malfunction will be caused. In addition, white noise processing for superposing a low-cost configuration is superimposed even when processing of weak signals is involved. Therefore, it is necessary to sharpen the bacterial image before image processing by appropriately performing background correction. Besides such background removal, the irradiation light for emitting light is extremely brighter than the excitation light, so this irradiation light must be appropriately cut and used.
[0020]
(2) Explanation of bacteria that emit excitation light of a specific wavelength
The background is a film having a resinous specimen-containing body or an adhesive layer for adhering bacteria. Both are colored as dark as possible in order to efficiently obtain excitation light from bacteria (with good contrast). However, it is not completely black but a dark gray level, and when it is irradiated with light, reflected light is generated.
[0021]
In this bacterial device, the inspection is not performed with the reflected light of the irradiated light, but a special chemical solution is contained in the bacteria, and ultraviolet light or green light is irradiated in this state. In response to the ultraviolet light or green light, excitation light is generated from bacteria containing the chemical solution. Specifically, as shown in FIGS. 8A and 8B, when ultraviolet light having a wavelength of 370 nm (NSHU 590) is irradiated, bacteria emit excitation light (exposure 1) at a wavelength of 461 nm. When green light having a wavelength of 525 nm (NSPG500S) is irradiated, excitation light (exposure 2) is generated at a wavelength of 617 nm.
[0022]
FIG. 8C shows the spectral characteristics of the filter. In addition to the weakness of the excitation light with respect to the irradiation light, the wavelengths of the irradiation light must be cut in the optical path for receiving light because the wavelengths are close to each other.
[0023]
For this reason, ultraviolet light is irradiated with a cut filter having a characteristic of abruptly decaying from 360 nm, so that the transmittance becomes 0% at a point of about 400 nm. Moreover, the light source NSPG 500S has almost no power at the 400 nm point. For this reason, excitation light (exposure 1) having a dominant wavelength of 461 nm can be appropriately acquired by inserting a filter that transmits a wavelength band of 420 nm or more, called L42, on the light receiving side. This excitation light is generated together with live and dead bacteria.
[0024]
Similarly, the green side uses a filter. For green light, a band-pass filter BP535 that transmits light in a band from 450 nm to 550 nm is attached to the green light source (536 nm). The light source NSPG 500S emits light in a wavelength band from 450 nm to 650 nm, but the base is cut by the bandpass filter described above. A filter called O58 that transmits a band of 580 nm or more is inserted on the light receiving side. Excitation light (exposure 2) having a dominant wavelength of 617 nm can be obtained. This excitation light is generated only for dead bacteria.
[0025]
As described above, the excitation light from the specimen can be acquired, but the wavelength range through which each passes is naturally left. Although the irradiation light source is filtered, the amount of light source is extremely large. In particular, the green light source has about 2000 lux on the specimen irradiation surface.
[0026]
For this reason, in spite of performing the cut filter processing as described above, only the excitation light cannot be picked up, and since the excitation light is weak, an exposure time of about 2 seconds is required, and a maximum of 255 decompositions as a background level is required. Sometimes it rises about 128. Since the number of pumping light outputs is 10 in this, it is preferable to remove the background level for subsequent image recognition.
[0027]
Embodiments of an imaging apparatus according to the present invention will be described below in detail with reference to the drawings.
[0028]
In this apparatus, a color image is not acquired at the same time, but a monotone image is acquired for two wavelengths by switching color filters. The object is irradiated with irradiation light (ultraviolet light and green light) of two different wavelengths from two pairs of light sources. In other words, all pixels have the same wavelength color at a certain acquisition timing, and the difference in optical path length for each wavelength is constant unless the lens system is changed. It is. However, in future developments, if the lens can be replaced for the purpose of optimizing the magnification as the number of types of imaging objects increases, the amount of optical path length correction will change and the adjustment means will have to be replaced. Needless to say.
[0029]
From this relationship, the subject, the switching filter, the lens unit, and the image sensor are configured in this order, and the switching filter has a configuration in which the thickness of each of the two different wavelength filters is changed.
[0030]
FIG. 1 is a side view of the entire imaging apparatus 1, and the main components are a stage 2 for placing a subject to be examined and an operation for placing a subject (specimen) on the stage 2. A front cover 5 that opens and closes, a light source unit 4 that irradiates light to the subject, and two-dimensional image light from the subject that has been irradiated by the light source unit 4 and emits excitation light from the reagent. The lens unit 3 for converting the image data into the image data, the filter moving unit 23 that supports a plurality of filters and moves to switch the filters in accordance with the switching of light emission, and further, when the specimen is placed on the previous stage 2 It comprises a stage moving unit 9 for moving the position from the above operability.
[0031]
FIG. 2 is a plan view of the light source unit 4 as viewed from above. The stage 2 is irradiated with light from the light source unit 4. The light source unit 4 includes four rod light sources 6a, a rod light source 6b, a rod light source 6c, and a rod light source 6d. Each rod light source 6 is attached to one mounting flange 51 so that the convergence position of each irradiation light is positioned on the optical axis of the lens means.
[0032]
Each rod light source 6 includes substrates 50a, 50b, 50c, and 50d at end portions, and light emitting diodes are respectively disposed on the substrate toward the inside of the rod. The rod light source 6a and the rod light source 6b emit light having the same wavelength (ultraviolet light having a wavelength of 370 nm) and work as a pair.
[0033]
The rod light source 6c and the rod light source 6d emit light having the same wavelength (green light having a wavelength of 525 nm) and work as a pair. As described above, the reason why the light is placed at the target position is to complement each other to make the irradiated surface substantially uniform. The pair of the rod light source 6a and the rod light source 6b and the pair of the rod light source 6c and the rod light source 6d do not light simultaneously and do not need to be orthogonal.
[0034]
With this configuration, the rod pair irradiates the irradiation stage with the imaging means disposed on the upper side so that the same illuminance is obtained at the same wavelength obliquely from the two positions symmetrical to the stage on the side of the imaging means. The projection area matches the stage so that there is no uneven illumination. Furthermore, if irradiation with light of a third different wavelength is necessary, a third pair of rod light sources may be added.
[0035]
Furthermore, U380 filters, which are cut filters for cutting off the skirt portions that are obstructed in the respective light emission distributions, are disposed in the rod light sources 6a and 6b. A BP535 filter is disposed in the rod light sources 6c and 6d to sharpen the light emission distribution.
[0036]
Samples to be examined for bacteria are fixed on a sample instrument called a membrane kit 40 that can be hydrated after the object is stirred with the reagent in the solution, or when the sample is directly collected by the film kit 41 having an adhesive surface There is. Furthermore, differently shaped fusers may be considered. As described above, since an enlarged image is formed on the image sensor by forming an enlarged image, the distance to the subject is extremely severe because the focal depth is small.
[0037]
For this reason, the stage 2 has three adjustment points, and adjusts not only the height adjustment but also the level. The fitting part (not shown) of the lens unit (camera) 3 with respect to the frame has a long hole so that it can be adjusted roughly so that it can be adjusted at these adjustment points. .
[0038]
FIG. 3 shows an example in which the membrane kit 40 is mounted on the stage 2 of the imaging apparatus. FIG. 4 shows a view in which the film kit 41 is mounted on the stage 2 of the imaging apparatus.
[0039]
Since the membrane kit 40 has the measuring part 40b on the upper part of the collar part 40a, the membrane kit 40 is higher than the collar part 40a. On the other hand, the film kit 41 is on a film and does not have such a height. On the other hand, since the lens unit 3 is a magnifying optical system and a solid contour shape is important for counting the number of subjects, the focal depth of imaging is extremely narrowed. Therefore, the height of the imaging surface must be the same between the two kits.
[0040]
In order to adjust the height, when the film kit 41 is mounted, the intermediate plate 42 is used to support the film. That is, since the stage 2 has a hole 20a for inserting the membrane kit, if the film is loaded as it is, the center will sink downward and a desired focal position cannot be obtained.
[0041]
FIG. 5 shows an example of a control block of the present apparatus. The operator instructs the data processing apparatus to start measurement. The instructed data processing apparatus sends a measurement start command to the imaging apparatus 1. The control unit 81 that has received the measurement start command via the interface 80 transmits measurement instruction data to the exposure control unit 82. The control means 81 has a filter moving means 23.
[0042]
The exposure control means 82 transmits exposure instruction data controlled for each rod light source 6 based on the instruction data received from the control means 81 to the irradiation means 83. The irradiation unit 83 that has received the exposure data performs irradiation for a predetermined number of times with respect to the specimen on the stage with light of a specific wavelength region for a predetermined exposure time. Then, the exposure time is controlled at least 0.2 seconds or more. At this time, the control means 81 adjusts the exposure time by controlling the transfer clock and / or reset pulse of the photoelectric conversion means 84.
[0043]
Further, when the control unit 81 needs to move the filter unit 55 based on the exposure instruction data instructed to each rod light source 6, the irradiation instruction data transmitted to the irradiation unit 83, and the current position of the filter unit 55. The filter moving unit 23 is instructed to move.
[0044]
Excitation light from the specimen on the stage 2 that emits light by irradiation light is collected by the lens unit 3 and transmitted to the photoelectric conversion unit 84. The photoelectric conversion means 84 transmits the received two-dimensional image signal to the A / D converter 85 for conversion into binary image data, and the A / D converter 85 sends the digitally converted data to the frame memory 86 as measurement data. Send. When the irradiation ends, the frame memory 86 transmits the accumulated data to the control means 81.
[0045]
Here, the optical path length adjustment mechanism in the present invention will be described.
[0046]
The stage 2 is positioned below the light emitting end opposite to the substrate mounting to which the light from the light source unit 4 is transmitted. A lens unit 3 is provided above the light emitting end, and a filter unit 55 that advances and retreats in parallel with the surface of the stage 2 is positioned between the lens unit 3 and the light emitting end. The filter unit 55 is provided with an L42 filter 55a that cuts light in a wavelength band below 420 nm and a 058 filter 55b that cuts light in a wavelength band below 580 nm (shown in FIGS. 1 and 2). .
[0047]
By being positioned above the light emitting end, light emission is prevented from directly hitting the filter. This is in view of the object that no scattered light is generated from an edge of a filter or stray light or the like and no obstacle is caused to light reception.
[0048]
Although it is conceivable to configure a switching filter in the lens unit, the point that it must be shielded from light becomes a difficult point and increases costs. Furthermore, as described above, there is a demerit in the case where the lens is configured to be replaceable.
[0049]
FIG. 6 shows a perspective view of the filter moving means 23. The filter moving unit 23 includes a driving unit 90 that gives a drive for moving the support frame 96 and the filter unit 55 in parallel with the surface of the stage 2, and a drive rod 91 that transmits the driving force of the driving unit 90 to the filter unit 55. The support frame 96 and a spring 92 that is locked to the drive lot 91 and biases the drive rod 91 toward the stage 2 side.
[0050]
When it is determined that the movement of the filter unit 55 is necessary due to the light source switching, the control unit 81 instructs the driving unit 90 of the filter moving unit to move the filter unit 55. The driving means 90 drives the filter unit 55 to advance and retract in parallel with the surface of the stage 2 via the driving rod 91.
[0051]
The filter unit 55 is formed with a guide hole 93 that guides the movement, and guides the movement direction and position so as not to deviate from the specified position. FIG. 6 shows a state where the L42 filter 55a that cuts a wavelength of 420 nm or less has moved to the imaging position. When the light source unit 4 emits green light, the driving unit 90 performs driving for movement, moves the filter unit 55 in the direction A of the arrow, and cuts light in the wavelength band below 580 nm. To the imaging position.
[0052]
By the way, the focal length of the lens 3a varies depending on the wavelength. For example, the green light received by the O58 filter 55b that cuts the wavelength band below 580 nm is shorter than the focal length of the ultraviolet light received by the L42 filter 55a that cuts the wavelength band of the lens 3a of 420 nm or less.
[0053]
Therefore, the light received by the 058 filter 55b that cuts the wavelength band below 580 nm is in front of the image sensor 96. An image in which this light reaches the image sensor 96 is in a so-called out-of-focus state. Therefore, in order to properly adjust the focal position, it is necessary to adjust (exchange) the position of the lens 3a, adjust the position of the image sensor 96, or adjust the subject position.
[0054]
Furthermore, the imaging apparatus 1 is an magnifying optical system, and unless the depth of focus is strictly observed, the contour extraction of an individual cannot be performed cleanly. Since it is a release exposure system, there is little background noise, and even when edge-coordinated image processing is performed, the original image quality is sufficiently required.
[0055]
Therefore, in the present invention, in order to adjust the focal length, one of the filters of the filter unit 55 is provided with the optical path length adjusting means 95 for adjusting the optical path length.
[0056]
FIG. 7 shows a configuration diagram of the subject 100, the filter unit 55, and lens means (lens unit 3).
[0057]
7A shows a focal position where the lens 3a is focused through the filter 55b in order to receive the excitation light from the subject 100. FIG. The focal position X is a focal position when excitation light (461 nm) from the subject 100 irradiated with ultraviolet light is received, and the focal position coincides with the light receiving surface of the image sensor 96. The focal position Y is a focal position when excitation light (617 nm) from the subject 100 irradiated with green light is received, and the focal position Y is in front of the light receiving surface of the image sensor 96.
[0058]
Thus, in order to solve the focal position shift due to the difference in the wavelength of light from the object to be read, as shown in FIG. 7B, the difference in optical path length (chromatic aberration) is appropriately adjusted even when irradiation light is changed. In order to complement, an optical path length adjusting means exchangeable with a filter and a separate member is provided for adjusting the optical path length.
[0059]
In the example of FIG. 7B, when excitation light (617 nm) from green light is received, an optical path length adjustment member 95 is placed on the filter 55b. In this example, the optical path length adjusting member is the adjusting glass 95.
[0060]
The excitation light from the subject 100 is refracted by the adjustment glass 95, and the optical path length is adjusted. By this adjustment, the focal position of the image passing through the lens 3a coincides with the light receiving surface of the image sensor 96. With the adjustment glass 95, the optical path length is adjusted, and it is possible to obtain precise light having a focal length for light of different wavelength regions from the subject.
[0061]
In this way, the optical path length adjusting means adjusts the focal position by overlapping the adjusting glass 95 on a predetermined filter. The filter unit 55 is moved by the filter moving unit 23 in accordance with an instruction from the control unit 81 based on information on the exposure unit, information on the irradiation unit, and information on the current filter type.
[0062]
In the imaging apparatus 1 according to the present invention, the subject 100 is mounted by moving the stage 2 to the front cover 5 opening position, opening the front cover 5 (shown in FIG. 1), and mounting the subject 100. In addition, since the apparatus can be operated from above the filter unit 55 during maintenance, the apparatus can be easily maintained even if dust adheres to the filter. In addition, since the filter unit 55 is provided in the space between the stage 2 and the lens unit 3 and the filter is positioned above the light emission position of the light source, it is necessary to enlarge the apparatus in order to provide the filter moving means 23. There is no. Furthermore, it can be said that the configuration is optically stable.
[0063]
Supplementally, there is a handling of the positional relationship of upper and lower in the description, but this is for convenience, and it is the same configuration to place the device diagonally or configure a horizontal device. Needless to say.
[0064]
Thus, the imaging apparatus according to the present invention can adjust the optical path lengths that are different in the wavelength region with a simple mechanism when imaging weak excitation light from a subject having a plurality of different wavelength regions, and thus has a small size. This makes it possible to precisely image the specimen without increasing noise light.
Further, by configuring the filter at such a position, the optical path length can be easily readjusted even when the filter is replaced to change the magnification of the lens.
[Brief description of the drawings]
FIG. 1 is a side view of an imaging apparatus with an optical path length adjusting unit according to the present invention.
FIG. 2 is a diagram mainly showing the periphery of a light source when the imaging apparatus of FIG. 1 is viewed from above.
3A is a plan view and FIG. 3B is a cross-sectional view in which a membrane kit is mounted on the stage of the imaging apparatus.
FIG. 4 shows a) a plan view and (b) a cross-sectional view in which a film kit is mounted on the stage of the imaging apparatus.
FIG. 5 is a control block diagram of the imaging apparatus.
FIG. 6 is a perspective view of filter moving means.
FIG. 7 is a configuration diagram of a subject, a filter unit, and a lens unit.
FIG. 8 is a diagram illustrating characteristics of a reagent, a light source, and a filter.
[Explanation of symbols]
1 Imaging device
2 stages
3 Lens unit (lens means)
4 Light source unit
5 Front cover
6 Rod light source
23 Filter moving means
40 membrane kit
41 Film kit
50 substrates
55 Filter unit
55a L42 filter
55b 058 filter
81 Control means
82 Exposure control means
83 Irradiation means
84 Photoelectric conversion means
85 A / D converter
86 frame memory
90 Drive means
95 Optical path length adjusting means
96 Image sensor

Claims (7)

An imaging device that images a minute subject that emits light at a wavelength different from the wavelength of the irradiation light according to the irradiation light in at least two wavelength regions, and converts the image to an electrical signal,
A stage to load the subject,
Light source means for illuminating the surface of the stage loaded with the subject;
Light switching means for switching the irradiation light emitted by the light source means to a plurality of light beams of different wavelength regions;
Lens means for condensing light from a subject illuminated by light rays of the plurality of different wavelength regions;
An image sensor for converting the two-dimensional image light collected by the lens means into an electrical signal;
Two or more filter means arranged in an optical path between the lens means and a position of emitting light emitted from the light source means, and switched according to switching of light rays by the light switching means;
A focal position on the light receiving surface of the image sensor corresponding to a change in the focal length of the lens means, which is arranged on at least one of the two or more filter means and is generated by switching the wavelength region of the irradiation light. an optical path length conversion means for but adjusting said stage to match the optical path length between the image sensor,
A magnifying imaging apparatus comprising:   The magnifying imaging apparatus according to claim 1, further comprising a moving unit that supports the two or more filter units and moves the filter unit in a direction intersecting a light receiving direction of the lens unit. The two or more filter means include
The magnifying imaging apparatus according to claim 1, wherein each of the magnifying imaging apparatuses is made of a material having a different thickness or refractive index. The irradiation light in the at least two wavelength regions is composed of irradiation light in two wavelength regions of ultraviolet light and green light,
The magnification imaging apparatus according to claim 1, wherein the optical path length adjustment unit is placed on a filter unit corresponding to the green light irradiation light.   The magnification imaging apparatus according to claim 1, further comprising an exposure control unit that controls an exposure time of the image sensor.   The magnification imaging apparatus according to claim 5, wherein an exposure time controlled by the exposure control unit is 0.2 seconds or more.   The light source means includes at least two rod-shaped light beam means, and the light beam means includes a light emitting element that emits a specific wavelength and a light converging means that converges light from the light emitting element. The magnification imaging apparatus according to claim 1, wherein the light beam is irradiated from the other end different from the end where the light emitting element is installed.

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