JP2009122482A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of enabling pleasant image observation by reducing occurrences of faults and reducing unnecessary adjustment of projection light. <P>SOLUTION: The projector 10 for projecting projection light includes: a detection lens system 12, which is a detection means for detecting a moving body present around the projector 10, and infrared camera 13; a determining means for determining whether the moving body detected by the detecting means is a target for the adjustment of an quantity of light, where the projection light enters a projection area, a quantity of projection light which requires adjustment is assumed as a target for the adjustment of a quantity of light; and a light quantity adjusting means for adjusting the quantity of projection light in response to the detection of the detecting means that the moving body determined as the target for the adjustment of the quantity of light by the determining means has moved into the area around the projection area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector, and more particularly to a technology of a projector that projects laser light.

  In recent years, a technique using a laser light source as a light source of a projector has been proposed. Laser light sources have been developed as light sources for projectors with higher output and more colors. Compared with UHP lamps conventionally used as projector light sources, laser light sources have advantages such as high color reproducibility, instant lighting, and long life. Equipment that uses a laser light source may cause a problem that affects the eyes when the laser light directly enters the eyes of a person. Therefore, a technique for reducing the occurrence of such a problem in a projector that uses a laser light source. Has been proposed. For example, Patent Document 1 proposes a technique for monitoring a monitoring area around a projection area with a camera. When there is a point different from the initial state in the video captured by the camera, the light amount of the laser light is reduced or the output of the laser light is stopped, assuming that a moving body that has moved enters the monitoring area.

JP 2005-31527 A

  The projector is assumed to be used in all situations. Not only when a person enters the monitoring area, but, for example, an object other than a person may enter the monitoring area. In addition, when there is a change in brightness in the monitoring area for some reason, an image captured by the camera may change from the initial state. In such a case, the light amount of the projection light may frequently be adjusted until it is not necessary to reduce the light amount of the projection light or stop the output of the projection light. If unnecessary adjustment of the amount of projection light is frequently made, comfortable image viewing is hindered. Thus, according to the conventional technique, there arises a problem that it is difficult to view a comfortable image. The present invention has been made in view of the above-described problems, and provides a projector that can reduce the occurrence of problems and reduce unnecessary adjustment of the amount of projection light, thereby enabling comfortable image viewing. Objective.

  In order to solve the above-described problems and achieve the object, a projector according to the present invention is a projector that projects projection light, and a detection unit that detects a moving body existing around the projector, and the projection light reaches If the entry target for adjusting the light quantity of the projection light projected from the projector when entering the projection area to be adjusted is set as the light quantity adjustment target, it is determined whether or not the moving body detected by the detecting means corresponds to the light quantity adjustment target. The light quantity of the projection light is adjusted according to the detection means and the detection means detecting that the moving body determined to be the light quantity adjustment target by the determination means has moved to the projection peripheral area around the projection area. And a light amount adjusting means.

  The light quantity of the projection light is obtained only when the moving body that is the object of light quantity adjustment moves to the projection peripheral region by determining in advance by the judgment means whether the moving body detected by the detection means corresponds to the light quantity adjustment target. Can be adjusted. For this reason, even if there is a change in the image captured by the detection means, it is possible to reduce unnecessary adjustment of the projection light when it is not necessary to reduce the amount of projection light or stop the output of projection light. As a result, it is possible to obtain a projector that can reduce the occurrence of problems and can reduce the unnecessary adjustment of the projection light to allow comfortable image viewing.

  As a preferred aspect of the present invention, it is desirable that the detection means captures an image of the moving body captured by the detection lens system. Thereby, the moving body existing around the projector can be detected.

  As a preferred aspect of the present invention, it is desirable that the horizontal angle of view of the detection lens system is 180 degrees or more and 360 degrees or less. Thereby, the periphery of the projector can be monitored in a wide range, and a moving body that can move to the projection peripheral area can be detected.

  Moreover, as a preferable aspect of the present invention, it is desirable that the detection means includes an infrared light detection unit that detects infrared light. Thereby, it is possible to detect the moving body and to determine whether or not the detected moving body corresponds to the light amount adjustment target. In particular, it is possible to easily identify the person who is the object of light quantity adjustment.

  Moreover, as a preferable aspect of the present invention, it is desirable that the detection means has a visible light detection unit that detects visible light. Thereby, it is possible to detect the moving body and to determine whether or not the detected moving body corresponds to the light amount adjustment target.

  In addition, as a preferable aspect of the present invention, a polarization separating unit that separates the first polarized light in the first vibration direction and the second polarized light in the second vibration direction substantially orthogonal to the first vibration direction, The visible light detection unit includes a first polarization detection unit that detects the first polarization separated by the polarization separation unit, and a second polarization detection unit that detects the second polarization separated by the polarization separation unit, Preferably, the determination unit determines whether or not the moving object falls under a light amount adjustment target based on a difference between a detection result by the first polarization detection unit and a detection result by the second polarization detection unit. Thereby, it is possible to detect a highly reflective member that is a light quantity adjustment target, and it is possible to reduce the occurrence of problems that may occur due to projection light reflected by the highly reflective member.

  Moreover, as a preferable aspect of the present invention, the wavelength separation unit that separates visible light and infrared light is included, and the polarization separation unit separates the visible light separated by the wavelength separation unit, and the infrared light detection unit It is desirable to detect the infrared light separated by the wavelength separation unit. Thereby, the mobile body detectable by the infrared light detection unit and the highly reflective member can be monitored simultaneously.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a state in which projection light is projected by the projector 10 according to the first embodiment of the present invention. The projector 10 is a front projection type projector that projects projection light onto a screen 11 and observes an image by observing light reflected by the screen 11. The projector 10 projects the projection light modulated according to the image signal onto the screen 11. The detection lens system 12 is provided on the outer surface of the projector 10.

  FIG. 2 shows a schematic configuration of the projector 10. The R light source unit 21R is a light source unit that emits red light (hereinafter referred to as “R light”) that is laser light. The G light source unit 21G is a light source unit that emits green light (hereinafter referred to as “G light”) that is laser light. The light source unit for B light 21B is a light source unit that emits blue light (hereinafter referred to as “B light”) that is laser light. The R light source unit 21R, the G light source unit 21G, and the B light source unit 21B include, for example, a semiconductor laser.

  The R light spatial light modulation device 22R is a spatial light modulation device that modulates the R light from the R light source unit 21R according to an image signal. The R light modulated by the R light spatial light modulator 22R enters the cross dichroic prism 23. The G light spatial light modulator 22G is a spatial light modulator that modulates the G light from the G light source unit 21G according to an image signal. The G light modulated by the G light spatial light modulator 22G is incident on a surface of the cross dichroic prism 23 different from the surface on which the R light is incident. The B light spatial light modulator 22B is a spatial light modulator that modulates the B light from the B light source unit 21B in accordance with an image signal. The B light modulated by the B light spatial light modulator 22B is incident on a surface of the cross dichroic prism 23 different from the surface on which the R light is incident and the surface on which the G light is incident.

  The cross dichroic prism 23 has two dichroic films 24 and 25 arranged substantially orthogonal to each other. The first dichroic film 24 reflects R light and transmits G light and B light. The second dichroic film 25 reflects B light and transmits R light and G light. The cross dichroic prism 23 combines R light, G light, and B light incident from different directions. The projection lens 26 projects the light synthesized by the cross dichroic prism 23. The R light spatial light modulation device 22R, the G light spatial light modulation device 22G, and the B light spatial light modulation device 22B are, for example, transmissive liquid crystal display devices. As the transmissive liquid crystal display device, for example, a high temperature polysilicon TFT liquid crystal panel (HTPS) can be used. The projector 10 may use an optical system for expanding and shaping the irradiation area and making the light amount distribution uniform for each color light.

  FIG. 3 shows a configuration for detecting a moving object. The moving body is an object that can enter the projection area by movement, for example, a person. The detection lens system 12 and the infrared light camera 13 function as detection means for detecting a moving body existing around the projector 10. The detection lens system 12 includes, for example, a 360 degree lens having a horizontal angle of view of 360 degrees. The infrared light camera 13 is an infrared light detection unit that detects infrared light. The infrared light camera 13 includes a plurality of light receiving elements (not shown) that convert incident infrared light into electronic signals. As the infrared light camera 13, for example, a CCD or CMOS sensor combined with a filter that blocks visible light and transmits infrared light can be used. The infrared camera 13 captures an image of the moving body captured by the detection lens system 12.

  FIG. 4 illustrates the projection area AR1 and the projection peripheral area AR2. The projection area AR <b> 1 is an area where the projection light projected from the projector 10 to the screen 11 reaches in the space between the projector 10 and the screen 11. The projection peripheral area AR2 is an area around the projection area AR1. In the present embodiment, the projection peripheral area AR2 is set so as to surround four sides of the projection area AR1. Thereby, the moving body that moves toward the projection area AR1 always passes through the projection peripheral area AR2 before entering the projection area AR1. Note that the projection peripheral area AR2 is not limited to being set so as to surround the four sides of the projection area AR1, but may be set at least at any position around the projection area AR1. The projection peripheral area AR2 may be set at a position where there is a high possibility that a person will enter the vicinity of the projection area AR1, for example, on the left and right of the projection area AR1.

  FIG. 5 illustrates the monitoring area of the infrared light camera 13 when the projector 10 and the periphery of the projector 10 are looked down from above. The monitoring area of the infrared camera 13 in the horizontal direction is set to a range of 360 degrees with the detection lens system 12 as the center. The projection area AR <b> 1 and the projection peripheral area AR <b> 2 are included in the monitoring area of the infrared camera 13. The infrared light camera 13 detects a moving body existing in the monitoring area. The monitoring area of the infrared light camera 13 in the vertical direction can be set to a position higher than the position where the projector 10 is disposed.

  FIG. 6 shows a block configuration for controlling the amount of projection light. The control unit 30 includes a CPU (Central Processing Unit) 34 and a memory 35, and functions as a computer. The memory 35 includes a flash ROM (Read Only Memory) or the like. The control unit 30 controls the driving of the projector 10 by operating the CPU 34 according to the control program stored in the memory 35. The image signal conversion unit 31 converts an image signal input from an external device or the like into a format that can be processed by the image signal processing unit 32. The image signal converter 31 converts the image signal based on the control by the controller 30. The image signal converter 31 converts, for example, an image signal input as an analog signal into a digital signal.

  The image signal processing unit 32 performs various image quality adjustment processes on the image signal converted by the image signal conversion unit 31. The processing for image quality adjustment includes, for example, resolution conversion for converting the resolution to match the number of pixels of each color light spatial light modulator 22R, 22G, 22B, brightness adjustment, contrast adjustment, sharpness adjustment, and the like. The spatial light modulation driving unit 33 drives the color light spatial light modulation devices 22R, 22G, and 22B based on the image signal processed by the image signal processing unit 32. The light source driving unit 36 drives each color light source unit 21R, 21G, 21B based on the control by the control unit 30.

  The imaging processing unit 37 processes an image captured by the infrared light camera 13. The imaging processing unit 37 recognizes the presence / absence of the moving object in the monitoring region and the position of the moving object based on the change in the infrared light based on the video in the initial state stored in advance. The imaging processing unit 37 functions as a determination unit that determines whether the moving body detected by the infrared light camera 13 corresponds to the light amount adjustment target. The light quantity adjustment target is an entry target that should adjust the light quantity of the projection light projected from the projector 10 when entering the projection area AR1. Since the projection light may directly enter the human eye, it may cause a problem that affects the eye, and thus the person corresponds to the light quantity adjustment target. The imaging processing unit 37 determines whether the moving body is a person based on the size and shape of the range in which the infrared light changes.

  When the moving body is not detected by the infrared light camera 13, the control unit 30 controls the light source units 21R, 21G, and 21B for each color light as usual. When the moving body is detected by the infrared light camera 13, the imaging processing unit 37 determines whether or not the moving body corresponds to a light amount adjustment target. When it is determined that the light quantity adjustment target is not applicable, the control unit 30 controls the color light source units 21R, 21G, and 21B as usual. When it is determined that the moving body corresponds to the light amount adjustment target and it is confirmed that the moving body has not moved to the projection peripheral area AR2, the control unit 30 performs the light source units 21R and 21G for each color light. , 21B is controlled as usual.

  When the infrared light camera 13 detects that the moving body determined to be a light amount adjustment target has moved to the projection peripheral area AR <b> 2, the light source driving unit 36 controls each color light source based on the control of the control unit 30. The power supply to the units 21R, 21G, and 21B is stopped. The output of the projection light is stopped by stopping the power supply to the color light source units 21R, 21G, and 21B. As described above, the control unit 30 performs projection in response to the detection by the infrared light camera 13 that the moving body that has been determined as the light amount adjustment target in the imaging processing unit 37 has moved to the projection peripheral area AR2. It functions as a light amount adjusting means for adjusting the amount of light. When a moving body that is determined to fall under the light amount adjustment target moves to the projection peripheral area AR2, the control unit 30 stops the output of the projection light and does not cause a problem even if it enters the light amount adjustment target. The amount of projection light may be reduced. By stopping the output of the projection light before the moving body enters the projection area AR1 or reducing the amount of the projection light, it is possible to prevent a situation in which strong projection light is incident on the moving body. Can be effectively reduced.

  When the moving body detected by the infrared light camera 13 corresponds to the light amount adjustment target by the imaging processing unit 37 in advance, the moving body as the light amount adjustment target moves to the projection peripheral area AR2. Only the amount of projection light can be adjusted. For this reason, even if there is a change in the image captured by the infrared light camera 13, it is possible to reduce unnecessary adjustment of the projection light when it is not necessary to reduce the amount of the projection light or stop the output of the projection light. Can do. As a result, it is possible to reduce the occurrence of defects and reduce the unnecessary adjustment of the projection light, thereby enabling a comfortable image viewing.

  The control unit 30 is not limited to the case where the light amount of the projection light is adjusted by controlling the light source units 21R, 21G, and 21B for each color light. The controller 30 may adjust the light amount of the projection light by controlling the spatial light modulators 22R, 22G, and 22B for each color light. For example, the output of the projection light can be stopped by expressing the lowest gradation in all pixels. The projector 10 may be provided with a shielding unit capable of shielding the projection light, and may stop the output of the projection light by controlling the shielding unit using the control unit 30.

  The detection lens system 12 is not limited to one having a 360 degree lens. The detection lens system 12 only needs to have a lens having a horizontal angle of view of 180 degrees or more and 360 degrees or less. The detection lens system 12 can capture the image of the moving body in a range of at least 180 degrees centered on the projection area AR1, thereby enabling monitoring of the periphery of the projector 10 in a wide range and moving to the projection peripheral area AR2. It is possible to detect moving objects that may The detection lens system 12 may include a fisheye lens.

  The projector 10 may use a visible light camera instead of the infrared light camera 13. The visible light camera is a visible light detection unit that detects visible light. By determining whether or not the moving body is a person based on the size and shape of the range in which visible light changes, it is not necessary to reduce the amount of projection light or stop the output of projection light. In this case, unnecessary adjustment of the projection light can be reduced.

  FIG. 7 shows a schematic configuration of a characteristic part of the projector according to the second embodiment of the invention. The projector of the present embodiment is characterized in that the amount of projection light can be adjusted when a mirror, which is a highly reflective member, moves to the projection peripheral area AR2. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. When the highly reflective member enters the projection area AR1, the projection light may travel from the projection area AR1 toward a person other than the projection area AR1. Applicable.

  The dichroic mirror 43 is disposed at a position where light from the detection lens system 12 enters. The dichroic mirror 43 reflects infrared light from the detection lens system 12 and transmits visible light. The dichroic mirror 43 functions as a wavelength separation unit that separates visible light and infrared light from the detection lens system 12. The infrared light camera 13 is disposed at a position where infrared light reflected by the dichroic mirror 43 is incident. The infrared light camera 13 detects the infrared light reflected by the dichroic mirror 43.

  The visible light that has passed through the dichroic mirror 43 enters the polarization beam splitter 44. The polarization beam splitter 44 is configured by bonding two triangular prisms. A polarization separation film 45 is formed on the joint surface of the two triangular prisms. The polarization separation film 45 transmits the first polarized light and reflects the second polarized light. The first polarized light is linearly polarized light in the first vibration direction, for example, p-polarized light. The second polarized light is linearly polarized light having a second vibration direction substantially orthogonal to the first vibration direction, for example, s-polarized light. The polarization beam splitter 44 functions as a polarization separation unit that further separates the visible light separated by the dichroic mirror 43 into a first polarization and a second polarization.

  The first polarized light that has passed through the polarization beam splitter 44 enters the first visible light camera 41. The first visible light camera 41 functions as a first polarization detection unit that detects the first polarized light separated by the polarization beam splitter 44. The second polarized light reflected by the polarization beam splitter 44 enters the second visible light camera 42. The second visible light camera 42 functions as a second polarization detection unit that detects the second polarized light separated by the polarization beam splitter 44. Both the first visible light camera 41 and the second visible light camera 42 are visible light detection units that detect visible light. The first visible light camera 41 and the second visible light camera 42 include a plurality of light receiving elements (not shown) that convert incident visible light into electronic signals. As the first visible light camera 41 and the second visible light camera 42, for example, a CCD or a CMOS sensor can be used. The detection lens system 12, the infrared light camera 13, the first visible light camera 41, and the second visible light camera 42 function as a detection unit that detects a moving body existing around the projector 10.

  FIG. 8 shows a block configuration for controlling the amount of projection light. The control unit 30 adjusts the amount of projection light using the detection result from the infrared camera 13 as in the case of the first embodiment. The imaging comparison unit 47 processes images captured by the first visible light camera 41 and the second visible light camera 42. The imaging comparison unit 47 determines whether the moving body is a highly reflective member based on the difference between the detection result by the first visible light camera 41 and the detection result by the second visible light camera 42. The imaging processing unit 37 and the imaging comparison unit 47 function as a determination unit that determines whether or not the moving body corresponds to a light amount adjustment target.

  Usually, the reflected light reflected by the highly reflective member is biased in the polarization component. The deviation of the polarization component increases as the reflectance of the reflecting member that reflects the light increases. When visible light whose polarization component is not biased is captured by the detection lens system 12, the image captured by the first visible light camera 41 and the image captured by the second visible light camera 42 match. . When there is no difference between the detection result by the first visible light camera 41 and the detection result by the second visible light camera 42, the imaging comparison unit 47 monitors the first visible light camera 41 and the second visible light camera 42. It is determined that there is no highly reflective member in the region. When the imaging comparison unit 47 determines that there is no highly reflective member, the control unit 30 controls the color light source units 21R, 21G, and 21B as usual.

  When visible light whose polarization component is biased is captured by the detection lens system 12, the image captured by the first visible light camera 41 and the image captured by the second visible light camera 42 do not match. A place will arise. When there is a difference between the detection result by the first visible light camera 41 and the detection result by the second visible light camera 42, the imaging comparison unit 47 determines that a highly reflective member exists in the monitoring area. In addition, the imaging processing unit 37 recognizes the position of the highly reflective member based on the position of the portion that does not match between the image captured by the first visible light camera 41 and the image captured by the second visible light camera 42. To do.

  While it is confirmed that the highly reflective member has not moved to the projection peripheral area AR2, the control unit 30 controls the color light source units 21R, 21G, and 21B as usual. When the first visible light camera 41 and the second visible light camera 42 detect that the highly reflective member has moved to the projection peripheral area AR <b> 2, the light source driving unit 36 uses the control unit 30 for each color light. The power supply to the light source units 21R, 21G, and 21B is stopped. In this way, by using the first visible light camera 41 and the second visible light camera 42, it is possible to detect a highly reflective member that is a light amount adjustment target, and a problem that may occur due to projection light reflected by the highly reflective member. Can be reduced.

  Even if the polarization component bias is detected, if the degree of the bias is low, it is determined that the reflection member has a low reflectance, so that even if the reflection member moves to the projection peripheral area AR2, the projection light The amount of light can be made normal. As a result, it is possible to adjust the light amount of the projection light only when it is necessary to reduce the light amount of the projection light or stop the output of the projection light. Furthermore, it is good also as adjusting the degree which reduces the light quantity of projection light according to the bias | inclination of a polarization component. Thereby, the adjustment amount of the light quantity of projection light can be made into the minimum, and generation | occurrence | production of a malfunction can be reduced effectively.

  The projector may omit the infrared light camera 13 and use the first visible light camera 41 and the second visible light camera 42 to determine in the imaging comparison unit 47 whether or not the moving body is a person. . By determining whether or not the moving body is a person based on the size and shape of the range in which the visible light changes, it is not necessary to reduce the amount of projection light or stop the output of projection light. In this case, unnecessary adjustment of the projection light can be reduced.

  The projectors of the above embodiments may be configured to use a solid light source other than a laser light source, a light emitting diode element (LED), or the like. The projector is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The projector is not limited to a configuration including a spatial light modulator for each color light. The projector may be configured to modulate two or three or more color lights with one spatial light modulator. The projector is not limited to the case where the spatial light modulator is used. The projector may be a laser scanning projector that scans the laser light from the light source device by scanning means such as a galvanometer mirror and displays an image on the irradiated surface. The projector may be a slide projector that uses a slide having image information. Further, the projector is not limited to a projector that is used in combination with a reflective screen that reflects projection light, and may be used in combination with a transmission screen that transmits projection light.

  As described above, the projector according to the present invention is suitable for displaying an image using laser light.

FIG. 3 is a diagram illustrating a state in which projection light is projected by the projector according to the first embodiment. FIG. 2 is a diagram illustrating a schematic configuration of a projector. The figure which shows the structure for detecting a moving body. The figure explaining a projection area and a projection peripheral area. The figure explaining the monitoring area | region of an infrared-light camera. The figure which shows the block structure for controlling the light quantity of projection light. FIG. 6 is a diagram illustrating a schematic configuration of a characteristic part of a projector according to a second embodiment. The figure which shows the block structure for controlling the light quantity of projection light.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Projector, 11 Screen, 12 Detection lens system, 13 Infrared camera, 21R R light source part, 21G G light source part, 21B B light source part, 22R R spatial light modulator, 22G G Spatial light modulation device for light, 22B spatial light modulation device for B light, 23 cross dichroic prism, 24 first dichroic film, 25 second dichroic film, 26 projection lens, AR1 projection area, AR2 projection peripheral area, 30 control unit, 31 Image signal conversion unit, 32 Image signal processing unit, 33 Spatial light modulation driving unit, 34 CPU, 35 Memory, 36 Light source driving unit, 37 Imaging processing unit, 41 First visible light camera, 42 Second visible light camera, 43 Dichroic mirror, 44 Polarization beam splitter, 45 Polarization separation film, 47 Imaging comparator

Claims (7)

A projector that projects projection light,
Detecting means for detecting a moving object existing around the projector;
When the entry target to adjust the light amount of the projection light projected from the projector when entering the projection area where the projection light reaches is a light amount adjustment target, the moving body detected by the detection means is the light amount adjustment. A determination means for determining whether or not the target is applicable,
The light amount of the projection light is adjusted in response to the detection means detecting that the moving body, which has been determined by the determination means as being subject to the light amount adjustment target, has moved to the projection peripheral area around the projection area. And a light amount adjusting means for adjusting.   The projector according to claim 1, wherein the detection unit captures an image of the moving body captured by a detection lens system.   The projector according to claim 2, wherein a horizontal angle of view of the detection lens system is 180 degrees or more and 360 degrees or less.   The projector according to claim 1, wherein the detection unit includes an infrared light detection unit that detects infrared light.   The projector according to claim 1, wherein the detection unit includes a visible light detection unit that detects visible light. A polarization separation unit that separates the first polarized light in the first vibration direction and the second polarized light in the second vibration direction substantially orthogonal to the first vibration direction;
The visible light detection unit includes a first polarization detection unit that detects the first polarization separated by the polarization separation unit, and a second polarization detection unit that detects the second polarization separated by the polarization separation unit. Have
The determination means determines whether or not the moving object falls under the light amount adjustment target based on a difference between a detection result by the first polarization detection unit and a detection result by the second polarization detection unit. The projector according to claim 5. It has a wavelength separation part that separates visible light and infrared light,
The polarization separation unit separates the visible light separated by the wavelength separation unit,
The projector according to claim 6, wherein the infrared light detection unit detects the infrared light separated by the wavelength separation unit.

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