JP2014123071A - Light uniformization coupler for spectrum sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently guide light received through an inlet to an outlet while uniformizing it.SOLUTION: A light uniformization coupler for a spectrum sensor forms a through-hole inner surface which is a light guide part stretching from the inlet of an optical guide side to the outlet of an optical system side by a reflection mirror, and sets the shape and the size of the reflection mirror so as to satisfy all three conditions, namely, a first condition that the ratio of an emitted light amount from the outlet full surface to an incident light amount from the inlet full surface is equal to or higher than a first predetermined ratio, a second condition that even when the incident position of the incident light at the inlet is changed, the fluctuation width of the ratio of the incident light amount incident at each incident position to the exist light amount from the outlet full surface is equal to or lower than a second predetermined ratio of a ratio when the exit light amount shows a maximum value, and a third condition that even when the incident position of the incident light at the inlet is changed, the minimum value of the exit light amount at a fluctuating outlet center position is equal to or higher than a third predetermined ratio of the maximum value.

Description

  The present invention relates to a light homogenizing and coupling device for a spectrum sensor that receives light from a measurement object side at an incident port and guides it to an output port on the sensor side with a spectrum sensor that measures optical characteristics.

  2. Description of the Related Art Conventionally, a spectrum sensor that measures the optical characteristics of paper sheets irradiates the paper sheets with light, and generates a spectrum from light reflected by the paper sheets or light transmitted through the paper sheets. The spectrum is acquired by imaging an interference fringe generated by an optical system including a prism or the like with an imaging element such as a CCD. Since the imaged spectrum changes according to the optical characteristics of the paper sheet to be measured, the optical characteristics of the paper sheet can be evaluated based on the characteristics obtained from the spectrum. In order to accurately measure the spectrum, it is necessary to guide the light from the paper sheet to a prism or the like in a uniform state without causing uneven brightness.

  As a technique for guiding light while making light uniform, for example, there is Koehler illumination. In Koehler illumination, the light collected by the condenser lens is made uniform by the projection lens using two lenses, a condenser lens and a projection lens. In addition, for example, as in Patent Document 1, there is a technique for condensing and guiding light from a light source by a light condensing unit in which a plate material having a reflective layer is formed into a cylindrical shape.

JP 2004-163624 A

  However, the prior art related to Koehler illumination requires the use of a plurality of lenses, and thus there is a problem that the structure becomes complicated and the manufacturing cost increases. Further, according to the conventional technique according to Patent Document 1, the structure can be simplified and the manufacturing cost can be suppressed. However, when this technique is applied to a small-sized spectrum sensor, the output indicating the ratio of the output light quantity to the incident light quantity is shown. There is a problem that the efficiency is lowered and the sensor performance is affected.

  Specifically, the light condensing unit disclosed in Patent Document 1 is used in a projector apparatus that projects an image on a screen, and light from a light source is directly incident on an incident port. Further, the size of the emission port is large and the emission efficiency does not become a problem. In contrast, spectrum sensors that measure the optical properties of paper sheets use reflected light or transmitted light from paper sheets as incident light, so the amount of incident light is lower than when light from a light source is directly incident. Get smaller. Further, in a spectrum sensor that is smaller in size than the projector device, the width of the exit port may be only a few millimeters, and the amount of emitted light is further reduced. If a sufficient amount of emitted light cannot be obtained at the exit, the sensor performance of the spectrum sensor is degraded, and the optical characteristics of the measurement object cannot be measured accurately. For this reason, in order to combine optical components with a small spectrum sensor, there is a need for a technique that can obtain a sufficient amount of emitted light to measure optical characteristics while making the light uniform and suppressing the occurrence of uneven brightness. It was.

  The present invention has been made in order to solve the above-described problems caused by the prior art, and receives light from a measurement object at an entrance and efficiently guides the light to the exit on the sensor side while making the light uniform. An object of the present invention is to provide a light uniformizing and coupling device for a spectrum sensor.

  In order to solve the above-described problems and achieve the object, the present invention provides a light guide for receiving light from a paper sheet, an optical system unit for generating a spectrum from light received by the light guide, and A spectrum sensor having a sensor unit for imaging the generated spectrum, wherein the light guide and the optical system unit are optically coupled to each other. A reflection mirror that forms an inner surface of the through hole from the incident port on the side to the emission port on the optical system side, and the shape and size of the reflection mirror is the entire surface of the emission port with respect to the amount of incident light from the entire surface of the incident port The first condition in which the ratio of the amount of light emitted from the light source is equal to or greater than a first predetermined ratio, even if the incident position of incident light at the incident port is changed, the incident light amount incident at each incident position and the emission from the entire surface of the outlet Ratio to light intensity A second condition in which the fluctuation range is equal to or less than a second predetermined ratio of the ratio when the amount of emitted light has a maximum value, and the center position of the emission port that varies even if the incident position of incident light at the incident port is changed. The minimum value of the amount of emitted light at is set so as to satisfy all of the third conditions that are equal to or greater than a third predetermined ratio of the maximum value.

  In the present invention, the first predetermined ratio is set to 30%, the second predetermined ratio is set to 30%, and the third predetermined ratio is set to 50%.

  Moreover, the present invention is characterized in that, in the above invention, the reflecting mirror forms a truncated pyramid shape with the entrance and the exit having a smaller area than the entrance as a bottom.

  Moreover, the present invention is the above invention, wherein the angle between the vertical surface passing through the center in the width direction of the entrance and the two side surfaces in the width direction of the truncated pyramid shape is 13.5 degrees or less, The angle between the vertical plane passing through the center in the height direction of the entrance and the two side surfaces of the truncated pyramid shape in the height direction is 4.6 degrees or less.

  According to the present invention, in the light uniformizing and coupling device for a spectrum sensor used in a small spectrum sensor, the shape and size of the reflection mirror that forms the inner surface of the through hole from the entrance to the exit are Even if light of a predetermined ratio or more is emitted from the exit and the incident position at the entrance changes, the total amount of emitted light does not fluctuate by more than the prescribed ratio and the minimum value of the emitted light at the center of the exit is the maximum value. Since it is set so as to be a predetermined ratio or more, the light from the paper sheet received by the light guide is incident from the entrance, and the amount of light is sufficient to obtain the optical characteristics of the paper sheet while making it uniform. Light can be emitted toward the optical system unit.

FIG. 1 is a diagram for explaining a schematic structure of a spectrum sensor including a light homogenizing / combining device for a spectrum sensor according to the present embodiment. FIG. 2 is a diagram for explaining the progress of light inside the light homogenizing / combining device for a spectrum sensor according to the present embodiment. FIG. 3 is a perspective view showing an appearance of the light uniformizing and combining device for a spectrum sensor according to the present embodiment. FIG. 4 is a diagram for explaining the inner surface shape of the light uniformizing and combining device for a spectrum sensor according to the present embodiment. FIG. 5 is a diagram for explaining the relationship between the incident position of light at the entrance and the intensity distribution of light emitted from the exit in the light homogenizing / combining device for a spectrum sensor according to this embodiment. FIG. 6 is a diagram for explaining the relationship between the incident light amount and the emitted light amount when the distance from the incident port to the output port is changed in the light homogenizing / combining device for a spectrum sensor according to the present embodiment. FIG. 7 is a diagram for explaining the structure of a light homogenizing / combining device for a spectrum sensor. FIG. 8 is a diagram showing a different structure example of a spectrum sensor including a light homogenizing and combining device for a spectrum sensor.

  Exemplary embodiments of a light uniformizing and combining device for a spectrum sensor according to the present invention will be explained below in detail with reference to the accompanying drawings. In the following, a case will be described as an example in which a light guide for receiving light from a paper sheet and an optical system unit are optically coupled by using a light uniformizing and coupling device for a spectrum sensor. In the following description, the light homogenizing and coupling device for a spectrum sensor is referred to as an “optical coupling device”.

  First, an outline of the structure of a spectrum sensor 100 in which the optical coupling device 1 according to the present embodiment is used will be described with reference to FIG. The spectrum sensor 100 includes a light guide 10, an optical coupling device 1, an optical system unit 20, and a sensor unit 30, and converts light indicating the optical characteristics of the paper sheet 3 into an electrical signal. It has a function of outputting to an external signal processing unit. For example, as shown in FIG. 1C, the spectrum sensor 100 irradiates light on the paper sheet 3 from the light source 2 and reflects the light reflected from the paper sheet 3 into 16 light receiving units of the light guide 10. Light is received by 212a to 212p.

  As shown in FIGS. 1A and 1B, the light guide 10 is formed of four light guide plates 10a to 10d formed of a transparent member such as an acrylic resin. The light guide plate 10a has four light receiving portions 212a to 212d provided so as to face the paper sheet 3, and the light receiving portions 212a to 212d have the same height from the paper sheet 3 as X. They are arranged at equal intervals in one row in the axial direction. The light received by the four light receiving parts 212a to 212d is guided in the X-axis direction while being totally reflected inside, and is emitted from the emission part 212q toward the optical system part 20. The other light guide plates 10b to 10d have the same function. As shown in FIG. 1B, in the state where the four light guide plates 10a to 10d are arranged so that the end portions on the optical coupling device 1 side are aligned in the Y-axis direction, each of the 16 light receiving portions 212a to 212p. Are arranged at equal intervals in one row in the X-axis direction. As shown in FIG. 1B, by transporting the paper sheet 3 in the Y-axis direction on the transport path 4, the entire surface of the paper sheet is received by the light receiving portions 212a to 212p arranged in a line in the X-axis direction. Can be measured. Light emitted from the four light guide plates 10 a to 10 d becomes incident light to the optical coupling device 1.

  Although not shown in the figure, the optical system unit 20 includes a cut filter for cutting light of a predetermined wavelength, a diffusion plate for diffusing light, a polarizing plate and a prism for generating interference fringes, and interference fringes. A lens for focusing on the sensor unit 30 that captures the image is included.

  Although not shown, the sensor unit 30 includes a CCD, which is an image sensor for imaging the interference fringes generated by the optical system unit 20, a substrate for controlling the CCD, and the like. Light from the paper sheet 3 is received by the light guide 10, an interference fringe is generated from the light by the optical system unit 20, and the interference fringe is imaged by the sensor unit 30.

  The spectrum sensor 100 is used in, for example, a paper sheet identification device that identifies the paper sheet 3. In the paper sheet identification device, for example, a process of generating a distribution map indicating the frequency of incident light and its intensity characteristic from the signal output from the sensor unit 30 to identify the type, authenticity, etc. of the paper sheet 3 is performed. Done.

  Next, details of the optical coupling device 1 according to the present embodiment will be described. The optical coupling device 1 has a function of guiding light emitted from the light guide 10 to the optical system unit 20. FIG. 2 is a diagram for explaining how light travels inside the optical coupling device 1. In the optical coupling device 1, the area of the exit (right side of the drawing) that is the opening on the sensor unit 30 side is smaller than the entrance (left side of the drawing) that is the opening on the light guide 10 side. The inner surface of the light guide portion connecting the light exit and the exit is formed by a reflection mirror. Light that has entered the light guide from the entrance of the optical coupling device 1 travels while being reflected by the reflection mirror on the inner surface of the light guide without reaching the outside of the light guide.

  As shown in FIG. 2, the light incident from the point 41 of the entrance port as shown by the broken line is reflected by the reflection mirror on the inner surface and exits from the exit port. On the other hand, as shown by the solid line from the point 42 at the entrance, the light incident on the inner surface is repeatedly reflected by the reflection mirror, and then returns to the exit without reaching the exit. As described above, light incident from the incident port of the optical coupling device 1 is emitted from the emission port toward the optical system unit 20 depending on the incident position and angle, and returned to the incident port as return light. This return light causes a decrease in emission efficiency. Since the amount of return light generated varies depending on the structure of the optical coupling device 1, it is necessary to realize the emission efficiency necessary for the measurement of the optical characteristics with the structure of the optical coupling device 1 as appropriate. In order to perform identification processing of the paper sheet 3 by the spectrum sensor 100, it is desirable that the emission efficiency is 30% or more.

  Next, a specific structure of the optical coupling device 1 that can be used for the small spectrum sensor 100 and can obtain an emission efficiency of 30% or more will be described. FIG. 3 is a perspective view showing the appearance of the optical coupling device 1. As shown in FIG. 3, the optical coupling device 1 has a through hole from the light guide 10 side to the optical system unit 20 side, and this through hole serves as a light guide unit for guiding incident light. Four reflection mirrors 111 to 114 are used on the inner surface of the light guide unit so as to reflect incident light. That is, it is a through-hole having two truncated pyramid-shaped bottoms as openings, and four side surfaces in the hole are formed by four reflecting mirrors 111 to 114.

  FIG. 4 is a diagram illustrating the shape of the light guide unit formed by the four reflection mirrors 111 to 114 in the optical coupling device 1. FIG. 4A illustrates the size of the light guide unit. FIGS. 4B and 4C show a cross-sectional view perpendicular to the Y axis and a cross-sectional view perpendicular to the Z axis, respectively, including the light guide. As shown in FIG. 4A, the entrance 101 and the exit 102, which are openings, each have a rectangular shape of 22 mm long × 15 mm wide and 18 mm long × 3 mm wide. The sizes of the entrance 101 and the exit 102 are set so as to satisfy the conditions described later. The ridgeline length H (mm) is also determined so that the emission efficiency is 30% or more, which will be described later.

  FIG. 5 is a diagram illustrating the intensity distribution of the emitted light at the exit 102 when the light source is placed at a different position at the entrance 101 of the optical coupling device 1 shown in FIG. As shown in the left diagram of FIG. 5A, a position 201 near the center of the entrance 101, a position 202 that is the center in the Y-axis direction but hits the end in the Z-axis direction, and the Y-axis direction and the Z-axis direction. The position of the light source is set to each of the positions 203 that are both ends. As shown in the right figure of FIG. 5A, the distribution of the emission intensity in the Z-axis direction up to the position of 18 mm at the upper end with the lower end of the emission port 102 set to 0 (zero) mm is shown in FIG. ). As shown in FIG. 5B, in the distribution curve 301 of the emission intensity when the light source is the center position 201, the emission intensity is almost uniform, and a high emission intensity can be obtained. In the distribution curve 302 when the light source is moved to the end in the Z-axis direction with the center position in the Y-axis direction being distributed, the distribution of the emission intensity is almost uniform, but compared with the case where the center position 201 is the light source. The emission intensity is lowered. Further, in the distribution curve 303 in the case where the light source is set at the upper corner position 203 of the incident port 101, a high emission intensity can be obtained in the vicinity of Z = 18 mm as in the case where the central position 201 is used as the light source. The emission intensity decreases, and the emission intensity becomes substantially 0 (zero) at the position of Z = 0 (zero) mm in FIG.

  Thus, the intensity distribution of the light emitted from the exit port 102 varies greatly depending on the position of the light incident from the entrance port 101. Therefore, three conditions are set for the relationship between the light incident from the incident port 101 and the light emitted from the output port 102, and the structure of the optical coupling device 1 is designed to satisfy all these conditions.

  First, the first condition is that the emission efficiency indicating the ratio of the light amount emitted from the entire exit port 102 to the light amount incident from the entire entrance port 101 is 30% or more. This first condition is that the amount of emitted light sufficient to measure the optical properties of the paper sheet 3 is obtained with respect to the amount of incident light.

  Next, as shown in FIG. 5, even if the position of the light source at the entrance 101 is changed, the fluctuation range of the amount of light obtained from the entire exit port 102 is the maximum value among the amounts of light obtained at all the entrance positions. The second condition is that it is within 30% of the quantity of light indicating That is, this is a condition for a change in the light obtained from the entire exit port 102 when the position of the light incident from the entrance port 101 changes. As shown in FIG. 5 (b), the second condition is that when the output intensity distribution curves 301 to 303 at the respective incident positions are obtained and the integral value, which is the amount of emitted light, is calculated from each distribution curve, the integration is performed. The condition is that the difference between the distribution curve 301 showing the maximum value and the distribution curve 303 showing the minimum value is within 30% of the maximum value. FIG. 5 shows the intensity distribution of the emitted light when the amount of incident light is the same. In other words, the ratio of the emitted light amount to the incident light amount is the maximum value and the minimum value. The condition is that the difference in fluctuation is within 30% of the maximum value.

  Furthermore, as shown in FIG. 5, even if the position of the light source at the entrance 101 is changed, the amount of light obtained at the center of the exit 102 shows the maximum value among the amounts of light obtained at all the entrance positions. The third condition is that the light quantity is 50% or more. That is, this is a condition for a change in the light obtained from the center position of the exit port 102 when the position of the light incident from the entrance port 101 changes. As shown in FIG. 5B, the third condition is that the distribution curves 301 to 303 of the emission intensity at each incident position are obtained, and the distribution curve 301 in which the emission intensity at the position of Z = 9 mm shows the maximum value. Assuming that the value is Smax, the value on the distribution curve 303 where the emission intensity at the position of Z = 9 mm is the minimum value is 50% or more of Smax.

  The second condition and the third condition are based on the condition that in addition to obtaining a sufficient amount of emitted light, uniform light can be obtained without greatly changing the amount of emitted light depending on the position of incident light. In the example of FIG. 5, the positions of the light source are the three positions 201 to 203 shown in FIG. 5A, and the distribution curves 301 to 303 of the obtained emitted light are shown in FIG. The conditions were explained using the results shown in FIG. However, in actually determining whether or not each of the first condition to the third condition is satisfied, light from the light source is set at 32 locations (circular shape in the figure) shown in FIG. The determination is performed with the diffusion angle of 60 degrees.

  If all the conditions from the first condition to the third condition are satisfied, the light emitted from the emission port 102 is uniformed and becomes light without unevenness of brightness, and this light is emitted toward the optical system unit 20. The optical characteristics of the paper sheet 3 can be measured and used for the paper sheet 3 identification process.

  FIG. 6 is a diagram illustrating an example of a result of verifying the first condition and the second condition. As shown in FIG. 6A, the incident position of light is set at the incident position 204 at the center of the incident port 101 where the amount of light emitted from the emission port 102 is maximum, and at the corner of the incident port 101 where the amount of emitted light is minimum. The incident position 205 is set. In FIG. 6B, the horizontal axis is the length of the ridge line H (mm), and the vertical axis indicates the emission efficiency when light is incident from the incident position 204 and the emission efficiency when light is incident from the incident position 205. And the ratio of these emission efficiencies. In FIG. 6B, the left vertical axis indicates the output efficiency at each of the incident positions 204 and 205, and the right vertical axis indicates the ratio (%) of the output efficiency.

  When the center of the entrance 101 is the entrance position 204, the longer the ridge line H, that is, the greater the distance from the entrance 101 to the exit 102, the greater the distance from the light source, and thus the emission efficiency decreases. On the other hand, when the corner of the entrance 101 is the entrance position 205, the longer the ridge line H is, the more the light travels in the X-axis direction while being reflected by the reflecting mirrors 111 to 114 on the inner surface of the light guide. Since the amount of light reaching 102 increases, the emission efficiency is improved. As shown in FIG. 6B, by setting the length of the ridge line H to H = 15 mm or more, the first condition is satisfied at both the incident positions 204 and 205, and the emission efficiency is 30% or more. Further, by setting the length of the ridge line H to H = 25 mm or more, the emission efficiency at the incident position 205 with respect to the emission efficiency at the incident position 204 shows a value of 70% or more. That is, when the same amount of light is incident from the incident positions 204 and 205, the variation in the amount of emitted light is within 30% of the amount of light at the incident position 205 where the amount of emitted light is maximum, so that the second condition is satisfied.

  Further, if the length of the ridge line H shown in FIG. 6A is H = 25 mm, the third condition is satisfied with each of the 32 positions shown in FIG. From the above results, it is possible to satisfy all the conditions of the first condition to the third condition by setting the length of the ridge line H to H = 25 mm or more.

  That is, as shown in FIG. 4, in the optical coupling device 1 in which the light guide portion is formed by the four reflection mirrors 111 to 114, the length of the ridge line H in the drawing is set to H = 25 mm, The light incident on 101 can be emitted from the emission port 102 while being made uniform, and a sufficient amount of emitted light can be obtained to measure the optical characteristics of the paper sheet 3. In addition, a small optical coupling device 1 having a vertical, horizontal, and depth of 30 mm or less can be realized and used for a small spectrum sensor 100 as shown in FIG.

  FIG. 7 is a diagram illustrating the structure of the optical coupling device 1 that satisfies all of the first to third conditions described above. 7A is a structure of the light guide unit of the optical coupling device 1, FIG. 7B is a side view of the light guide unit viewed from the Y-axis direction, and FIG. 7C is a side view of the light guide unit in the Z-axis direction. The top view seen from is shown. FIG. 7D shows a mathematical expression showing the relationship between the width α1 of the entrance 101 and the width α2 of the exit 102 when all the conditions are satisfied, and the height β1 of the entrance 101 and the height of the exit 102. And a mathematical expression showing the relationship with β2. Here, L shown in FIG. 7D is the distance between the entrance 101 and the exit 102, and the angle θα is the angle between the XZ plane and the reflection mirror 111 (113) on the side of the light guide section, and the angle θβ. Is the angle between the XY plane and the reflecting mirror 112 (114) on the side of the light guide. As shown in FIG. 7B, the height direction center line of the entrance port 101 and the height direction center line of the exit port 102 coincide with each other, and as shown in FIG. The line and the center line in the width direction of the exit port 102 coincide. By forming the reflection mirrors 111 to 114 on the respective side surfaces of the light guide so that the angle θα is 13.5 degrees or less and the angle θβ is 4.6 degrees or less, all the conditions of the first condition to the third condition are satisfied. It can be set as the structure which satisfy | fills. In addition, as above-mentioned, the light guide part has the magnitude | size formed in the small optical coupling apparatus 1 whose length, width, and depth are all 30 mm or less.

  The structure of the spectrum sensor 100 using the optical coupling device 1 is not limited to that shown in FIG. FIG. 8 shows different structural examples of the spectrum sensor 100. As shown in FIG. 8, the size of the spectrum sensor 100 in the X-axis direction can be reduced by using the light guide unit 5 that bends the light traveling direction from the light guide 10 toward the optical coupling device 1 by 90 degrees. It becomes possible. In this case, the light guide unit 5 may be formed by extending the light emitting unit 212q side of the light guide 10 and bending it 90 degrees, or an optical fiber connecting between the light guide 10 and the optical coupling device 1. It may be formed by a bundle or the like. The angle at which the light traveling direction is bent is determined according to the size of the spectrum sensor 100 and the space in which it is installed, and is not limited to 90 degrees.

  As described above, according to the present embodiment, even when the size of the entrance 101 on the light guide 10 side formed in accordance with the paper sheet 3 is different from the size of the exit 102 on the optical system unit 20 side, These can be optically coupled by the optical coupling device 1. In addition, light received from the light receiving portions 212 a to 212 p of the light guide 10 is incident from the incident port 101 while the optical coupling device 1 is a small device having a length, width, and depth of several tens of millimeters according to the spectrum sensor 100. The light quantity sufficient to measure the optical characteristics of the paper sheet 3 and perform the identification process can be emitted from the emission port 102 toward the optical system unit 20.

  As described above, the present invention is a small-sized spectrum sensor for measuring optical characteristics of paper sheets and the like, and the light guide side entrance and the optical system side exit are different in size. This is a useful technique for optically coupling the two.

DESCRIPTION OF SYMBOLS 1 Optical coupling apparatus 2 Light source 3 Paper sheets 4 Conveyance path 5 Light guide part 10 Light guide 10a-10d Light guide plate 20 Optical system part 30 Sensor part 100 Spectrum sensor 101 Incident opening 102 Outlet openings 111-114 Reflection mirrors 212a-212p Light receiving part 212q emitting part

Claims (4)

A spectrum sensor having a light guide for receiving light from paper sheets, an optical system for generating a spectrum from light received by the light guide, and a sensor for imaging the generated spectrum, A light uniformizing and coupling device for a spectrum sensor that optically couples between the light guide and the optical system unit,
A reflection mirror that forms an inner surface of the through hole from the light guide side incident port to the optical system side emission port;
The shape and size of the reflecting mirror are
A first condition in which the ratio of the amount of light emitted from the entire surface of the exit port to the amount of light incident from the entire surface of the entrance port is equal to or greater than a first predetermined ratio;
Even when the incident position of the incident light at the incident port is changed, the fluctuation range of the ratio between the incident light amount incident at each incident position and the emitted light amount from the entire surface of the exit port is when the emitted light amount shows the maximum value. A second condition that is less than or equal to a second predetermined ratio of the ratio, and a third value that is a minimum value of the output light quantity at the center position of the output port that varies even if the incident position of the incident light at the input port is changed. A light uniformizing and coupling device for a spectrum sensor, characterized in that it is set so as to satisfy all the conditions of the third condition which is a predetermined ratio or more.   2. The light uniformizing and coupling device for a spectrum sensor according to claim 1, wherein the first predetermined ratio is set to 30%, the second predetermined ratio is set to 30%, and the third predetermined ratio is set to 50%.   3. The light uniformizing and coupling device for a spectrum sensor according to claim 1, wherein the reflection mirror forms a truncated pyramid shape with the entrance and the exit having a smaller area than the entrance as a bottom surface. 4.   The angle between the vertical plane passing through the width direction center of the entrance and the two side surfaces of the truncated pyramid shape in the width direction is 13.5 degrees or less, and passes through the height direction center of the entrance. The light uniformizing and coupling device for a spectrum sensor according to claim 3, wherein an angle between the vertical surface and each of the two side surfaces in the height direction of the truncated pyramid is 4.6 degrees or less. .

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