JP2019132607A - Spectrometer - Google Patents

Abstract

To provide a spectrometer that can be downsized as compared with a spectrometer using a diffraction grating.SOLUTION: A spectrometer 1 comprises: a light-receiving element 110 and a wavelength selection filter unit 200. The light-receiving element 110 includes a pixel region 112 in which a plurality of pixels 111 are arranged. The wavelength selection filter unit 200 is arranged in the pixel region 112 and includes a plurality of wavelength selection filters 210, 220, 230, 240, 250 and 260. Each of the wavelength selection filters 210 to 260 has such a transmission wavelength characteristic that the transmission wavelength changes continuously or stepwise from one end to the other end in a first direction. The wavelength selection filter unit 200 has such a transmission wavelength characteristic that, while the wavelength selection filters 210 to 260 are arranged in a row in the first direction so that the respective ends in the first direction of the wavelength selection filters 210-260 come in contact with each other, the transmission wavelength changes continuously from one end to the other end.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a spectrometer.

  Patent Document 1 describes a spectroscope that separates incident light using a diffraction grating. A spectroscope using a diffraction grating separates incident light by utilizing the fact that the diffraction angle varies depending on the wavelength.

JP 2011-202971 A

  In a spectroscope using a diffraction grating, it is necessary to increase the distance from the diffraction grating to the light receiving element in order to separate and detect the incident light that has been dispersed. Therefore, in a spectroscope using a diffraction grating, downsizing of the spectroscope is a problem.

  An object of this invention is to provide the spectrometer which can be reduced in size compared with the spectrometer using a diffraction grating.

  The present invention includes a light receiving element having a pixel region in which a plurality of pixels are arranged, and a wavelength selection filter unit that is arranged on the pixel region and has a plurality of wavelength selection filters. The wavelength selection filter unit has a transmission wavelength characteristic in which a transmission wavelength changes from one end portion in the first direction toward the other end portion, and each wavelength selection filter unit has each end portion in the first direction of the wavelength selection filter. In a state where the wavelength selective filters are arranged in a line in the first direction so that the end faces of the wavelength selective filters are in contact with each other, from one end of the wavelength selective filter unit in the first direction to the other end A spectrometer having a transmission wavelength characteristic in which the transmission wavelength continuously changes is provided.

  According to the spectroscope of the present invention, the size can be reduced as compared with a spectroscope using a diffraction grating.

It is an exploded view which shows the structural example of the spectrometer of 1st Embodiment. It is a side view which shows the structural example of the spectrometer of 1st Embodiment. It is a top view which shows the structural example of a wavelength selection filter unit. It is a side view which shows the structural example of a wavelength selection filter. It is a side view which shows the structural example of a wavelength selection filter. It is a top view which shows the state which arranged the some wavelength selection filter which comprises a wavelength selection filter unit in 1 row. It is a figure which shows the relationship between each wavelength selection filter and a transmission wavelength in the state shown to FIG. 5A. It is a top view which shows the prior art example of the cutting method of the transparent substrate in which the some wavelength selection filter is formed. It is a side view which shows the prior art example of the cutting method of the transparent substrate in which the some wavelength selection filter is formed. It is a flowchart for demonstrating the production method of a wavelength selection filter unit. It is a top view which shows one Example of the cutting method of the transparent substrate in which the some wavelength selection filter is formed. It is a side view which shows one Example of the cutting method of the transparent substrate in which the some wavelength selection filter is formed. It is a top view which shows one Example of the cutting method of the transparent substrate in which the some wavelength selection filter is formed. It is a side view which shows one Example of the cutting method of the transparent substrate in which the some wavelength selection filter is formed. It is a side view which shows the structural example of the spectrometer of 2nd Embodiment. It is a side view which shows the structural example of the spectrometer of 3rd Embodiment. It is a side view which shows the structural example of the spectrometer of 4th Embodiment.

[First Embodiment]
A configuration example of the spectrometer according to the first embodiment will be described with reference to FIGS. 1, 2, 3, 4A, 4B, 5A, and 5B. As shown in FIG. 1 or FIG. 2, the spectrometer 1 includes a light receiving device 100, a wavelength selection filter unit 200, and an optical element 300.

  The light receiving device 100 includes a base 101, a plurality of terminals 102, a control element 103, and a light receiving element 110. The plurality of terminals 102, the control element 103, and the light receiving element 110 are fixed to the base 101. The control element 103 and the light receiving element 110 are connected to a plurality of terminals 102.

  The control element 103 controls the light receiving element 110 based on a control signal input from at least one of the plurality of terminals 102 from the outside. The control element 103 is an arithmetic element such as an IC (Integrated Circuit).

  The light receiving element 110 includes a pixel region 112 in which a plurality of pixels 111 are arranged in a first direction (for example, the X direction) and a second direction (for example, the Y direction) orthogonal to the first direction. The light receiving element 110 photoelectrically converts light (incident light) incident on the pixel region 112 for each pixel 111 to generate a light reception signal.

  The light receiving element 110 is a semiconductor element such as a complementary metal oxide semiconductor (CMOS), a charge-coupled device (CCD), or a photodiode array. The light receiving element 110 outputs a light reception signal to the control element 103. The control element 103 processes the received light signal and outputs it to the outside via at least one of the plurality of terminals 102.

  The wavelength selection filter unit 200 is disposed on the pixel region 112 of the light receiving element 110. The wavelength selection filter unit 200 may be disposed in contact with the pixel region 112 or may be disposed separately. FIG. 2 shows a state where the wavelength selection filter unit 200 is in contact with the pixel region 112.

  The wavelength selection filter unit 200 includes a plurality of wavelength selection filters 210, 220, 230, 240, 250, and 260. Each of the wavelength selection filters 210, 220, 230, 240, 250, and 260 has an elongated shape including a longitudinal direction (first direction) and a short direction (second direction). The second direction, which is the short direction, is orthogonal to the first direction, which is the long direction. 1 and 3, six wavelength selection filters 210, 220, 230, 240, 250, and 260 are shown, but the number of wavelength selection filters is not limited to this, and is arbitrary. Can be set to

  As shown in FIG. 1 or FIG. 3, the wavelength selection filter unit 200 includes wavelength selection filters 210, 220, 230, 240, 250, and 260 arranged in the short direction. The longitudinal end surfaces EF211, EF212, EF221, EF222, EF231, EF232, EF241, EF242, EF251, EF252, EF261, and EF262 of the wavelength selective filters 210, 220, 230, 240, 250, and 260 are cut surfaces. is there.

  FIG. 1 shows a state in which the wavelength selection filter unit 200 is arranged so that the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260 is the X direction. The wavelength selection filter unit 200 may be arranged so that the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260 is the Y direction.

  The wavelength selection filters 210, 220, 230, 240, 250, and 260 have different transmission wavelength characteristics. As shown in FIG. 3, the wavelength selection filter 210 is a linear variable filter that selects and transmits light in the wavelength range of λa to λb (λa <λb) according to the position in the longitudinal direction, which is a predetermined direction. .

  The wavelength selection filter 210 has a transmission wavelength characteristic in which the transmission wavelength changes from λa to λb continuously or stepwise from one end 211 in the longitudinal direction to the other end 212. Therefore, the wavelength selection filter 210 can separate light in the wavelength range of λa to λb for each wavelength or wavelength band according to the position or range in the longitudinal direction.

  The wavelength selection filter 220 is a linear variable filter that selects and transmits light in the wavelength range of λb to λc (λb <λc) according to the position in the longitudinal direction, which is a predetermined direction. The wavelength selection filter 220 has a transmission wavelength characteristic in which the transmission wavelength changes from λb to λc continuously or stepwise from one end 221 in the longitudinal direction toward the other end 222. Therefore, the wavelength selection filter 220 can separate the light in the wavelength range of λb to λc for each wavelength or wavelength band according to the position or range in the longitudinal direction.

  The wavelength selection filter 230 is a linear variable filter that selects and transmits light in the wavelength range of λc to λd (λc <λd) according to the position in the longitudinal direction, which is a predetermined direction. The wavelength selection filter 230 has a transmission wavelength characteristic in which the transmission wavelength changes from λc to λd continuously or stepwise from one end 231 in the longitudinal direction toward the other end 232. Therefore, the wavelength selection filter 230 can separate the light in the wavelength range of λc to λd for each wavelength or wavelength band according to the position or range in the longitudinal direction.

  The wavelength selection filter 240 is a linear variable filter that selects and transmits light in the wavelength range of λd to λe (λd <λe) according to the position in the longitudinal direction, which is a predetermined direction. The wavelength selection filter 240 has a transmission wavelength characteristic in which the transmission wavelength changes from λd to λe continuously or stepwise from one end 241 in the longitudinal direction to the other end 242. Therefore, the wavelength selection filter 240 can separate light in the wavelength range of λd to λe for each wavelength or wavelength band according to the position or range in the longitudinal direction.

  The wavelength selection filter 250 is a linear variable filter that selects and transmits light in the wavelength range of λe to λf (λe <λf) according to the position in the longitudinal direction, which is a predetermined direction. The wavelength selection filter 250 has a transmission wavelength characteristic in which the transmission wavelength changes continuously or stepwise from λe to λf from one end 251 in the longitudinal direction toward the other end 252. Therefore, the wavelength selection filter 250 can separate light in the wavelength range of λe to λf for each wavelength or wavelength band according to the position or range in the longitudinal direction.

  The wavelength selection filter 260 is a linear variable filter that selects and transmits light in the wavelength range of λf to λg (λf <λg) according to the position in the longitudinal direction, which is a predetermined direction. The wavelength selection filter 260 has a transmission wavelength characteristic in which the transmission wavelength changes from λf to λg continuously or stepwise from one end 261 in the longitudinal direction toward the other end 262. Therefore, the wavelength selection filter 260 can separate light in the wavelength range of λf to λg for each wavelength or wavelength band according to the position or range in the longitudinal direction.

  A configuration example of the wavelength selection filters 210, 220, 230, 240, 250, and 260 will be described with reference to FIGS. 4A and 4B.

  As shown in FIG. 4A, the wavelength selection filters 210, 220, 230, 240, 250, and 260 each include a transparent substrate 270 and a dielectric multilayer film 280. The dielectric multilayer film 280 has a laminated structure in which dielectric films 281 having different refractive indexes are alternately laminated. With respect to the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260, each dielectric film 281 has a material parameter such as a film thickness or a material continuously changing.

  4A and 4B show a case where the film thickness of each dielectric film 281 changes continuously with respect to the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260. FIG. 4A and 4B are schematic diagrams in which the wavelength selection filters 210, 220, 230, 240, 250, and 260 are enlarged in the thickness direction in order to make the change in the thickness of each dielectric film 281 easier to understand. FIG.

  Each material parameter is set to be different depending on the wavelength selection filters 210, 220, 230, 240, 250, and 260. Thereby, the wavelength selection filters 210, 220, 230, 240, 250, and 260 have the above transmission wavelength characteristics. The wavelength selection filter unit 200 is desirably disposed so that the dielectric multilayer film 280 faces the pixel region 112.

  As shown in FIG. 4B, the wavelength selection filters 210, 220, 230, 240, 250, and 260 are dielectric multilayers on the surface of the transparent substrate 270 opposite to the surface on which the dielectric multilayer film 280 is formed. The dielectric multilayer film 282 having the same stacked structure as the film 280 may be formed.

  By forming the dielectric multilayer film on both surfaces of the transparent substrate 270, the stress of one dielectric multilayer film 280 with respect to the transparent substrate 270 can be offset by the other dielectric multilayer film 282. As a result, the warp in the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260 due to the one dielectric multilayer film 280 can be reduced by the other dielectric multilayer film 282.

  In FIG. 1, the wavelength selection filters 210, 220, 230, 240, 250, and 260 are shown in a state where the dielectric multilayer films 280 and 282 are omitted. In FIG. 2, the dielectric multilayer films 280 and 282 are shown in a simplified manner.

  The transmission wavelength characteristics of the wavelength selection filter unit 200 will be described with reference to FIGS. 5A and 5B.

  FIG. 5A shows a state in which the wavelength selection filters 210, 220, 230, 240, 250, and 260 are arranged in a line. Specifically, in FIG. 5A, the end surface EF212 of the wavelength selection filter 210 and the end surface EF221 of the wavelength selection filter 220 are in contact, and the end surface EF222 of the wavelength selection filter 220 and the end surface EF231 of the wavelength selection filter 230 are in contact. Indicates the state.

  5A further shows that the end face EF232 of the wavelength selection filter 230 and the end face EF241 of the wavelength selection filter 240 are in contact, the end face EF242 of the wavelength selection filter 240 and the end face EF251 of the wavelength selection filter 250 are in contact, and the wavelength The state where the end surface EF252 of the selection filter 250 and the end surface EF261 of the wavelength selection filter 260 are in contact with each other is shown.

  That is, FIG. 5A shows the wavelength selective filters 210, 220, 230, 240, 250 so that the end faces of the longitudinal ends of the wavelength selective filters 210, 220, 230, 240, 250, and 260 are in contact with each other. , And 260 are arranged in a line in the longitudinal direction. FIG. 5B shows the relationship between the transmission wavelengths of the wavelength selection filters 210, 220, 230, 240, 250, and 260 in the state shown in FIG. 5A.

  When the wavelength selection filters 210, 220, 230, 240, 250, and 260 are arranged in a line as shown in FIG. 5A, the wavelength selection filter unit 200 has one end in the longitudinal direction as shown in FIG. 5B. The transmission wavelength is from λa (first transmission wavelength) to λg (second transmission wavelength) from the end 211 of the wavelength selection filter 210 corresponding to λ toward the end 262 of the wavelength selection filter 260 corresponding to the other end. Transmission wavelength characteristics that continuously change to (wavelength).

  Therefore, the wavelength selection filter unit 200 having the wavelength selection filters 210, 220, 230, 240, 250, and 260 functions as a linear variable filter having a transmission wavelength characteristic in which the transmission wavelength continuously changes from λa to λg. .

  As shown in FIGS. 6A and 6B, when a dielectric multilayer film 280 is formed on one transparent substrate 270 and a plurality of wavelength selection filters 210, 220, 230, 240, 250, and 260 are formed, the wavelength The selection filters 210, 220, 230, 240, 250, and 260 are formed in succession.

  FIG. 6B shows a case where the film thickness of each dielectric film 281 changes continuously with respect to the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260. FIG. 6B is a schematic diagram in which the wavelength selection filters 210, 220, 230, 240, 250, and 260 are enlarged in the thickness direction in order to make it easy to understand the change in the film thickness of each dielectric film 281. .

  When the transparent substrate 270 is cut in the Y direction to separate the wavelength selection filters 210, 220, 230, 240, 250, and 260, the wavelength selection filters 210, 220, 230, 240, 250, In addition, the end portions 212, 221, 222, 231, 232, 241, 242, 251, 252, and 261 of 260 and the vicinity thereof are cut.

  Therefore, when the wavelength selective filter unit 200 is produced using the wavelength selective filters 210, 220, 230, 240, 250, and 260 produced by the cutting method shown in FIGS. 6A and 6B, the transmission wavelength shown in FIG. 5B is obtained. Characteristics cannot be obtained.

  Therefore, an embodiment of a method for manufacturing the wavelength selective filter unit 200 will be described with reference to the flowchart shown in FIG. 7 and FIGS. 8A, 8B, 9A, and 9B. The operator forms the dielectric multilayer film 280 on the plurality of transparent substrates 271 and 272 as shown in FIG. 8A, FIG. 8B, FIG. 9A, or FIG. 9B in step S1 of the flowchart shown in FIG. Accordingly, a plurality of wavelength selection filters 210, 220, 230, 240, 250, and 260 are continuously formed on the plurality of transparent substrates 271 and 272, respectively.

  8B and FIG. 9B show a case where the film thickness of each dielectric film 281 changes continuously with respect to the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260. Yes. 8B and 9B, the wavelength selection filters 210, 220, 230, 240, 250, and 260 are enlarged in the thickness direction so that the change in the thickness of each dielectric film 281 can be easily understood. FIG. Note that the operator may form the dielectric multilayer film 282 on the surface of the transparent substrate 270 opposite to the surface on which the dielectric multilayer film 280 is formed.

  In step S2, the operator, as shown in FIG. 8A or 8B, ends 211 and 212 of the wavelength selection filter 210, ends 231 and 232 of the wavelength selection filter 230, and an end 251 of the wavelength selection filter 250. And the cutting position is adjusted so that the cutting surface is located at 252 and the transparent substrate 271 is cut in the Y direction.

  Therefore, the end faces EF211, EF212, EF231, EF232, EF251, and EF252 in the longitudinal direction of the wavelength selection filters 210, 230, and 250 are cut surfaces. The end portions 221 and 222 of the wavelength selection filter 220 and the vicinity region thereof, the end portions 241 and 242 of the wavelength selection filter 240 and the vicinity region thereof, and the end portions 261 and 262 of the wavelength selection filter 260 and the vicinity region thereof are cut off. Is done.

  Further, the operator can produce a plurality of wavelength selection filters 210, 230, and 250 from one transparent substrate 271 by cutting the transparent substrate 271 in the X direction.

  In step S3, the operator, as shown in FIG. 9A or 9B, ends 221 and 222 of the wavelength selection filter 220, ends 241 and 242 of the wavelength selection filter 240, and an end 261 of the wavelength selection filter 260. And the cutting position is adjusted so that the cutting surface is located at 262, and the transparent substrate 272 is cut in the Y direction.

  Therefore, the end faces EF221, EF222, EF241, EF242, EF261, and EF262 in the longitudinal direction of the wavelength selection filters 220, 240, and 260 are cut surfaces. Note that the end portions 211 and 212 of the wavelength selection filter 210 and the vicinity region thereof, the end portions 231 and 232 of the wavelength selection filter 230 and the vicinity region thereof, and the end portions 251 and 252 of the wavelength selection filter 250 and the vicinity region thereof are cut off. Is done.

  Furthermore, the operator can produce a plurality of wavelength selection filters 220, 240, and 260 from one transparent substrate 272 by cutting the transparent substrate 272 in the X direction.

  In step S4, the operator combines the wavelength selection filters 210, 230, and 250 produced in step S2 with the wavelength selection filters 220, 240, and 260 produced in step S3. The wavelength selective filter unit 200 having the transmission wavelength characteristic shown in FIG. 5B can be manufactured.

  As shown in FIG. 1 or FIG. 2, the optical element 300 is disposed on the wavelength selection filter unit 200. The optical element 300 may be disposed in contact with the wavelength selection filter unit 200 or may be disposed separately. FIG. 2 shows a state where the optical element 300 is in contact with the wavelength selective filter unit 200.

  The optical element 300 makes incident light parallel light. For example, the optical element 300 can be configured to have a plurality of optical fibers or rod lenses to make incident light parallel light. The optical element 300 is not limited to this as long as the incident light can be converted into parallel light.

  Incident light converted into parallel light by the optical element 300 is split by the wavelength selection filter unit 200 for each wavelength or wavelength band. Incident light dispersed by the wavelength selection filter unit 200 is incident on the corresponding pixel 111.

  By bringing the optical element 300, the wavelength selection filter unit 200, and the light receiving element 110 into contact with each other, the optical path length of incident light that has been converted into parallel light by the optical element 300 can be shortened. As a result, the light transmitted through the wavelength selection filter unit 200 can be incident on the target pixel 111 with high accuracy.

  For example, the wavelength selection filters 210, 220, 230, 240, 250, and 260 correspond to 100 pixels 111 arranged in the X direction in the pixel region 112 in the longitudinal direction, and each in the short direction. Will be described with respect to the case where the pixel region 112 corresponds to 20 pixels 111 arranged in the Y direction.

  The wavelength selection filter 210 allows light of different wavelengths to enter the 100 pixels 111 arranged in the X direction. On the other hand, light of the same wavelength is incident on 20 pixels 111 arranged in the Y direction.

  The control element 103 can set the number of pixels in the X direction (m) and the number of pixels in the Y direction (n). When the number of pixels in the Y direction is set to 20 according to the length in the Y direction of the wavelength selection filter 210 (n = 20), the control element 103 sets the 20 pixels 111 arranged in the Y direction. select. Further, the control element 103 adds the light reception signals generated by the selected 20 pixels 111.

  The control element 103 outputs the added light reception signal to the outside via at least one of the plurality of terminals 102. By adding the light reception signals of the 20 pixels 111, the signal level of the output signal can be increased.

  Signal processing for adding the light reception signals of the 20 pixels 111 is effective when the amount of incident light is small. The control element 103 may output the light reception signals generated by the selected 20 pixels 111 without adding them, and may add the light reception signals outside.

  For example, when the number of pixels in the Y direction is set to 4 (n = 4), the control element 103 sets the four pixels 111 in the center of the 20 pixels 111 arranged in the Y direction. select. The four pixels 111 in the central part are located in the central part of the wavelength selection filter 210 in the short direction. Further, the control element 103 adds only the received light signals of the four selected pixels 111.

  The control element 103 outputs the added light reception signal to the outside via at least one of the plurality of terminals 102. The control element 103 may output the light reception signals generated by the four selected pixels 111 to the outside without adding them, and may add the light reception signals outside.

  By adding only the light reception signals of the pixel 111 at the center, the influence of crosstalk due to unnecessary light from the wavelength selection filter 220 adjacent to the wavelength selection filter 210 can be reduced. Detection accuracy can be improved by signal processing in which only the light reception signals of the pixel 111 at the center are added.

  The signal processing in the wavelength selection filters 220, 230, 240, 250, and 260 is the same as the signal processing in the wavelength selection filter 210.

  In the spectrometer 1, the wavelength selection filter unit 200 having the wavelength selection filters 210, 220, 230, 240, 250, and 260 has a transmission wavelength characteristic in which the transmission wavelength continuously changes from λa to λg. Function as.

  In the spectroscope 1, the wavelength selection filter unit 200 that functions as a linear variable filter separates incident light, and therefore the wavelength selection filter unit 200 can be disposed in the vicinity of the pixel region 112 of the light receiving element 110. Therefore, according to the spectroscope 1, it can be reduced in size compared with the spectroscope using a diffraction grating. Further, in the spectrometer 1, the wavelength selection filter unit 200 can be disposed in contact with the pixel region 112 of the light receiving element 110.

  In the spectrometer 1, the control element 103 can set the number of pixels in the X direction and the Y direction. The control element 103 sets the number of pixels large when the amount of incident light is small, sets the number of pixels small when improving the detection accuracy, and adds only the light reception signal of the pixel 111 at the center. . That is, according to the spectroscope 1, the signal processing of the light reception signal generated for each pixel 111 can be executed according to the purpose.

[Second Embodiment]
A configuration example of the spectrometer of the second embodiment will be described with reference to FIG. FIG. 10 corresponds to FIG. In order to make the explanation easy to understand, the same components as those of the spectrometer 1 of the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 10, the spectrometer 2 includes a light receiving device 100, a wavelength selection filter unit 200, and optical elements 300 and 400. The light receiving device 100 includes a base 101, a plurality of terminals 102, a control element 103, and a light receiving element 110. The plurality of terminals 102, the control element 103, and the light receiving element 110 are fixed to the base 101. The control element 103 and the light receiving element 110 are connected to a plurality of terminals 102. The light receiving element 110 has a pixel region 112 in which a plurality of pixels 111 are arranged in the X direction and the Y direction.

  The optical element 300 (first optical element) converts incident light into parallel light. Incident light converted into parallel light by the optical element 300 enters the wavelength selection filter unit 200. The wavelength selection filter unit 200 includes wavelength selection filters 210, 220, 230, 240, 250, and 260. The wavelength selection filters 210, 220, 230, 240, 250, and 260 each include a transparent substrate 270 and a dielectric multilayer film 280.

  The dielectric multilayer film 280 is formed on the surface of the transparent substrate 270 that faces the optical element 400. The wavelength selection filters 210, 220, 230, 240, 250, and 260 have a configuration in which a dielectric multilayer film 282 is formed on the surface of the transparent substrate 270 opposite to the surface on which the dielectric multilayer film 280 is formed. It is good.

  Incident light is split by wavelength selection filter unit 200 for each wavelength or wavelength band. Incident light split by the wavelength selection filter unit 200 enters the optical element 400.

  The optical element 400 (second optical element) is disposed in the gap between the wavelength selection filter unit 200 and the light receiving element 110. The optical element 400 may be disposed in contact with the wavelength selection filter unit 200 and the light receiving element 110, or may be disposed separately. FIG. 10 shows a state where the optical element 400 is in contact with the wavelength selection filter unit 200 and the light receiving element 110.

  The optical element 400 has the same function as the optical element 300. That is, the optical element 400 makes incident light parallel light. For example, the optical element 400 can have incident light as parallel light by having a configuration including a plurality of optical fibers or rod lenses. The optical element 400 is not limited to this as long as the incident light can be converted into parallel light.

  Incident light split by the wavelength selection filter unit 200 and converted into parallel light by the optical element 400 is incident on the corresponding pixel 111 of the pixel region 112 of the light receiving element 110.

  The control element 103 controls the light receiving element 110 based on a control signal input from at least one of the plurality of terminals 102 from the outside. The light receiving element 110 photoelectrically converts the light incident on the pixel region 112 for each pixel 111 to generate a light reception signal.

  The light receiving element 110 outputs a light reception signal to the control element 103. The control element 103 processes the received light signal and outputs it to the outside via at least one of the terminals 102. The control element 103 of the spectrometer 2 performs the same signal processing as the control element 103 of the spectrometer 1.

In the spectroscope 2, the wavelength selection filter unit 200 including the wavelength selection filters 210, 220, 230, 240, 250, and 260 has a transmission wavelength characteristic in which the transmission wavelength continuously changes from λa to λg. Function as.
It works.

  In the spectroscope 2, the wavelength selection filter unit 200 that functions as a linear variable filter divides incident light, so that the wavelength selection filter unit 200 can be disposed in the vicinity of the pixel region 112 of the light receiving element 110. Therefore, the spectroscope 2 can be downsized as compared with a spectroscope using a diffraction grating.

  In the spectrometer 2, the control element 103 can set the number of pixels in the X direction and the Y direction. The control element 103 sets the number of pixels large when the amount of incident light is small, sets the number of pixels small when improving the detection accuracy, and adds only the light reception signal of the pixel 111 at the center. . That is, according to the spectroscope 2, signal processing of the light reception signal generated for each pixel 111 can be executed according to the purpose.

  According to the spectroscope 2, the incident light split by the wavelength selection filter unit 200 is converted into parallel light by the optical element 400, so that it can be accurately incident on the target pixel 111.

[Third Embodiment]
A configuration example of the spectrometer of the third embodiment will be described with reference to FIG. FIG. 11 corresponds to FIG. 2 and FIG. In order to make the explanation easy to understand, the same components as those of the spectrometers 1 and 2 of the first and second embodiments are denoted by the same reference numerals.

  As shown in FIG. 11, the spectroscope 3 includes a light receiving device 100, a wavelength selection filter unit 200, and optical elements 300 and 500. The light receiving device 100 includes a base 101, a plurality of terminals 102, a control element 103, and a light receiving element 110. The plurality of terminals 102, the control element 103, and the light receiving element 110 are fixed to the base 101. The control element 103 and the light receiving element 110 are connected to a plurality of terminals 102. The light receiving element 110 has a pixel region 112 in which a plurality of pixels 111 are arranged in the X direction and the Y direction.

  The optical element 300 makes incident light parallel light. Incident light converted into parallel light by the optical element 300 enters the wavelength selection filter unit 200. The wavelength selection filter unit 200 includes wavelength selection filters 210, 220, 230, 240, 250, and 260. The wavelength selection filters 210, 220, 230, 240, 250, and 260 each include a transparent substrate 270 and a dielectric multilayer film 280.

  The dielectric multilayer film 280 is formed on the surface of the transparent substrate 270 that faces the optical element 500. The wavelength selection filters 210, 220, 230, 240, 250, and 260 have a configuration in which a dielectric multilayer film 282 is formed on the surface of the transparent substrate 270 opposite to the surface on which the dielectric multilayer film 280 is formed. It is good.

  Incident light is split by wavelength selection filter unit 200 for each wavelength or wavelength band. Incident light separated by the wavelength selection filter unit 200 enters the optical element 500.

  A plurality of microlenses 501 are formed on the surface of the optical element 500 that faces the pixel region 112 of the light receiving element 110. In other words, the optical element 500 includes a plurality of microlenses 501 that face the pixel region 112. An area where one microlens 501 is formed corresponds to an area where, for example, 20 pixels 111 are arranged in the X direction and the Y direction in the pixel area 112, respectively.

  The optical element 500 makes incident light parallel light. The plurality of microlenses 501 focus the incident light that has been converted into parallel light by the optical element 500 onto the pixel region 112. Incident light dispersed by the wavelength selection filter unit 200 is converged for each wavelength band by the plurality of microlenses 501 and enters the corresponding pixels 111 of the pixel region 112 of the light receiving element 110.

  The control element 103 controls the light receiving element 110 based on a control signal input from at least one of the plurality of terminals 102 from the outside. The light receiving element 110 photoelectrically converts the light incident on the pixel region 112 for each pixel 111 to generate a light reception signal.

  The light receiving element 110 outputs a light reception signal to the control element 103. The control element 103 processes the received light signal and outputs it to the outside via at least one of the plurality of terminals 102. The control element 103 of the spectrometer 3 performs the same signal processing as the control element 103 of the spectrometer 1.

  In the spectroscope 3, the wavelength selection filter unit 200 including the wavelength selection filters 210, 220, 230, 240, 250, and 260 is a linear variable filter having a transmission wavelength characteristic in which the transmission wavelength continuously changes from λa to λg. Function as.

  In the spectroscope 3, the wavelength selection filter unit 200 that functions as a linear variable filter divides incident light, so that the wavelength selection filter unit 200 can be disposed in the vicinity of the pixel region 112 of the light receiving element 110. Therefore, the spectroscope 3 can be downsized as compared with a spectroscope using a diffraction grating.

  In the spectroscope 3, the control element 103 can set the number of pixels in the X direction and the Y direction. The control element 103 sets the number of pixels large when the amount of incident light is small, sets the number of pixels small when improving the detection accuracy, and adds only the light reception signal of the pixel 111 at the center. . That is, according to the spectroscope 3, the signal processing of the light reception signal generated for each pixel 111 can be executed according to the purpose.

  According to the spectroscope 3, incident light separated by the wavelength selection filter unit 200 can be accurately incident on the target pixel 111 for each wavelength band by the plurality of microlenses 501.

  According to the spectroscope 3, incident light dispersed by the wavelength selection filter unit 200 is converged by the plurality of microlenses 501 and enters the target pixel 111. Accordingly, the signal level of the light reception signal generated by the target pixel 111 can be increased, which is effective when the amount of incident light is small. Further, according to the spectroscope 3, crosstalk caused by incident light in a wavelength band near the target wavelength band entering the target pixel 111 can be prevented by the plurality of microlenses 501.

[Fourth Embodiment]
A configuration example of the spectrometer of the fourth embodiment will be described with reference to FIG. FIG. 12 corresponds to FIG. 2, FIG. 10, and FIG. In addition, in order to make explanation easy to understand, the same reference numerals are given to the same components as the spectrometers 1 to 3 of the first to third embodiments.

  As shown in FIG. 12, the spectroscope 4 includes a light receiving device 100, a wavelength selection filter unit 200, and an optical element 300. The light receiving device 100 includes a base 101, a plurality of terminals 102, a control element 103, and a light receiving element 110. The plurality of terminals 102, the control element 103, and the light receiving element 110 are fixed to the base 101. The control element 103 and the light receiving element 110 are connected to a plurality of terminals 102. The light receiving element 110 has a pixel region 112 in which a plurality of pixels 111 are arranged in the X direction and the Y direction.

  The optical element 300 makes incident light parallel light. Incident light converted into parallel light by the optical element 300 enters the wavelength selection filter unit 200. The wavelength selection filter unit 200 includes wavelength selection filters 210, 220, 230, 240, 250, and 260. The wavelength selection filters 210, 220, 230, 240, 250, and 260 each include a transparent substrate 270 and a dielectric multilayer film 280.

  The dielectric multilayer film 280 is formed on the surface facing the pixel region 112 of the light receiving element 110. The wavelength selection filters 210, 220, 230, 240, 250, and 260 have a configuration in which a dielectric multilayer film 282 is formed on the surface of the transparent substrate 270 opposite to the surface on which the dielectric multilayer film 280 is formed. It is good.

  Incident light is split by wavelength selection filter unit 200 for each wavelength or wavelength band. Incident light dispersed by the wavelength selection filter unit 200 is incident on the corresponding pixel 111 of the pixel region 112 of the light receiving element 110.

  In the pixel region 112 of the light receiving element 110, microlenses 113 are formed corresponding to the respective pixels 111. Incident light dispersed by the wavelength selection filter unit 200 is focused by the microlens 113 and enters the corresponding pixel 111.

  The control element 103 controls the light receiving element 110 based on a control signal input from at least one of the plurality of terminals 102 from the outside. The light receiving element 110 photoelectrically converts the light incident on the pixel region 112 for each pixel 111 to generate a light reception signal.

  The light receiving element 110 outputs a light reception signal to the control element 103. The control element 103 processes the received light signal and outputs it to the outside via at least one of the plurality of terminals 102. The control element 103 of the spectrometer 4 performs the same signal processing as the control element 103 of the spectrometer 1.

  In the spectrometer 4, the wavelength selection filter unit 200 including the wavelength selection filters 210, 220, 230, 240, 250, and 260 is a linear variable filter having a transmission wavelength characteristic in which the transmission wavelength continuously changes from λa to λg. Function as.

  In the spectroscope 4, the wavelength selection filter unit 200 that functions as a linear variable filter divides incident light, so that the wavelength selection filter unit 200 can be disposed in the vicinity of the pixel region 112 of the light receiving element 110. Therefore, the spectroscope 4 can be downsized as compared with a spectroscope using a diffraction grating.

  In the spectroscope 4, the control element 103 can set the number of pixels in the X direction and the Y direction. The control element 103 sets the number of pixels large when the amount of incident light is small, sets the number of pixels small when improving the detection accuracy, and adds only the light reception signal of the pixel 111 at the center. . That is, according to the spectroscope 4, the signal processing of the light reception signal generated for each pixel 111 can be executed according to the purpose.

  In the spectroscope 4, the incident light dispersed by the wavelength selection filter unit 200 is focused by the microlens 113 and is incident on the center of the corresponding pixel 111. Thereby, the detection accuracy of the target pixel 111 can be improved.

  In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change variously.

  In the spectrometers 1 to 4 according to the first to fourth embodiments, the wavelength selection filter unit 200 is arranged so that the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260 is the X direction. However, the wavelength selection filter unit 200 may be arranged such that the longitudinal direction of the wavelength selection filters 210, 220, 230, 240, 250, and 260 is the Y direction.

  The positional relationship of the wavelength selection filters 210, 220, 230, 240, 250, and 260 is not limited to the configuration of the wavelength selection filter unit 200 of the spectrometers 1 to 4 of the first to fourth embodiments. You may arrange arbitrarily.

  In the spectroscope 1 according to the first embodiment, the wavelength selection filters 210, 220, 230, 240, 250, and 260 are manufactured using the plurality of transparent substrates 271 and 272, but the invention is not limited to this. For example, after the wavelength selection filters 210, 220, 230, 240, 250, and 260 are formed on one transparent substrate 270, the transparent substrate 270 is cut into a plurality of transparent substrates 271 and 272, and the transparent substrate 271 is cut. The wavelength selective filters 210, 230, and 250 may be manufactured, and the wavelength selective filters 220, 240, and 260 may be manufactured from the cut transparent substrate 272.

1, 2, 3, 4 Spectrometer 110 Light receiving element 111 Pixel 112 Pixel region 113,501 Micro lens 200 Wavelength selection filter unit 210, 220, 230, 240, 250, 260 Wavelength selection filter 300, 400, 500 Optical element

Claims (2)

A light receiving element having a pixel region in which a plurality of pixels are disposed;
A wavelength selection filter unit disposed on the pixel region and having a plurality of wavelength selection filters;
With
Each wavelength selection filter has a transmission wavelength characteristic in which the transmission wavelength changes from one end portion in the first direction toward the other end portion,
In the state where the wavelength selection filters are arranged in a row in the first direction such that the end faces of the end portions in the first direction of the wavelength selection filter are in contact with each other. A spectrometer having a transmission wavelength characteristic in which a transmission wavelength continuously changes from one end of the wavelength selective filter unit in the first direction to the other end. The spectroscope according to claim 1, wherein each of the end faces of the plurality of wavelength selection filters is a cut surface.

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