JP2011048285A - Multichannel spectrum light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: output light beams with a plurality of wavelengths are not simultaneously output with one unit of a spectrum light source device using micromirrors. <P>SOLUTION: The multichannel spectrum light source device includes: a light source to emit light source light extending over a prescribed wavelength region; a slit to transmit a portion of the light source light; a wavelength dispersion element to conduct wavelength dispersion of the light source light; a modulation element to make one or more specified regions, selected from a plurality of split regions resulting from a two-dimensional split of a flat region irradiated with the light source light along a direction corresponding to a wavelength dispersion direction and a direction vertical thereto, reflect or transmit the light source light differently from other regions; and a control section to guide the light source light to each of a plurality of output regions corresponding to the vertical direction by controlling the specified regions of the modulation element. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a multi-channel spectrum light source device.

  Conventionally, as described in Patent Document 1, for example, a tunable light source that is irradiated with illumination light having a desired selected spectrum is known. In addition to the tunable light source shown here, for example, a light source device using a micromirror array device as a modulation element is known. In the micromirror array device, a plurality of micromirrors are two-dimensionally arranged, and the reflection direction of each micromirror can be controlled in two directions.

Special table 2007-506485 gazette

  A conventional spectrum light source device using a micromirror array device uses one side of a two-dimensionally arranged micromirror as a wavelength dispersion direction for wavelength selection, and an effective reflection area in the other side. The amount of light was attenuated by adjusting. Therefore, one device can have only one output channel. That is, a plurality of different spectrum output lights could not be output at the same time.

  In order to solve the above problems, a multi-channel spectrum light source device according to the first aspect of the present invention includes a light source that emits light source light over a predetermined wavelength region, a slit that allows a part of the light source light to pass through, and a light source light. One selected from a wavelength dispersion element that performs wavelength dispersion and a plurality of divided regions that are two-dimensionally divided along a direction corresponding to the wavelength dispersion direction and a direction orthogonal to the direction corresponding to the wavelength dispersion direction. By controlling the modulation element that reflects or transmits the light source light so that two or more specific areas are different from the other areas, and the specific area of the modulation element, each of the light sources has a plurality of output areas corresponding to orthogonal directions. And a controller for guiding light.

  The above summary of the invention does not enumerate all necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a conceptual diagram explaining the principle of the spectrum light source device by a 1st layout. It is a conceptual diagram explaining the principle which outputs the wavelength of (lambda) 1 in the spectrum light source device by a 2nd layout. It is a conceptual diagram explaining the principle which outputs the wavelength of (lambda) 2 in the spectrum light source device by a 2nd layout. 1 is a schematic configuration diagram of a multi-channel spectrum light source device according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating an imaging relationship in the optical system of the multi-channel spectrum light source device according to the first embodiment. It is a figure which shows the passage mode of the chief ray of each light beam channel of the multichannel spectrum light source device which concerns on Example 1. FIG. 6 is a schematic configuration diagram of a multi-channel spectrum light source device according to Embodiment 2. FIG. FIG. 6 is a diagram illustrating an imaging relationship in an optical system of a multi-channel spectrum light source device according to a second embodiment. It is a figure which shows the passage state of the chief ray of each light beam channel of the multichannel spectrum light source device which concerns on Example 2. FIG. 6 is a schematic configuration diagram of a multi-channel spectrum light source apparatus according to Embodiment 3. FIG. 6 is a schematic configuration diagram of a multi-channel spectrum light source device according to Embodiment 4. FIG.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  First, prior to specific description of the present embodiment, the principle of the spectrum light source device according to the present embodiment will be described. FIG. 1 is a conceptual diagram illustrating the principle of the spectrum light source device according to the first layout.

  Of the irradiation region 1101 irradiated by the light source that emits light over a certain wavelength region, the slit light 1103 that passes through the slit 1102 reaches the diffraction grating 1104 that is a wavelength dispersion element. The diffraction grating 1104 reflects and disperses light having various wavelengths mixed at an angle corresponding to the wavelength. As the diffraction grating 1104, for example, a reflection type planar grating is used, and the groove shape on the surface thereof is formed such that the wavelength in the reflection direction is defined according to the reflection angle with respect to the incident angle of incident light. ing. Therefore, when the slit light 1103 enters the diffraction grating 1104, the slit light 1103 is diffracted on the surface, and is reflected and dispersed as diffracted light having a characteristic wavelength in the direction corresponding to the reflection angle.

  The slit light 1103 includes, for example, a first reflected light 1105 that is reflected light having a wavelength λ1, a second reflected light 1106 that is reflected light having a wavelength λ2, and a third reflected light 1107 that is reflected light having a wavelength λ3, as illustrated. To disperse. Each reflected light is dispersed in the direction of the reflective liquid crystal element array 1108. Since the first reflected light 1105, the second reflected light 1106, and the third reflected light 1107 are slit lights, the first reflected light 1105, the second reflected light 1110, and the third reflected light 1107 of the reflective liquid crystal element array 1108 are slit-shaped. To reach. Each region has a strip shape in the row direction in the planar region of the reflective liquid crystal element array 1108, and n1 × n2 (n1 and n2 are both natural numbers, and n1 is in the row direction) reflective liquid crystal elements. Correspond. In the figure, for convenience, three wavelengths are shown, but the dispersed wavelengths may be continuously changed.

  The reflective liquid crystal element array 1108 includes a plurality of reflective liquid crystal elements that are two-dimensionally arranged. In each liquid crystal element, the amount of retardation given to incident light by the control unit is changed independently. Be controlled. Specifically, in the planar region irradiated with the light source light, one or more selected from a plurality of divided regions that are two-dimensionally divided along a direction corresponding to the wavelength dispersion direction and a direction orthogonal thereto. Each reflective liquid crystal element is independently controlled so that the polarization state of a specific region differs from the polarization state of other regions. Thereby, the light source light reflected by the specific area of the reflective liquid crystal element array 1108 has a polarization state different from that of the light source light reflected by the other area. For example, it is the same as that used for a liquid crystal projector.

  The control unit drives the reflective liquid crystal element in the specific region where the light of the wavelength to be output reaches, and reflects the polarization state of the specific region so that it is different from the changed state of the other regions. In the figure, the reflective liquid crystal element corresponding to a part of the first region 1109, which is the region irradiated with the first reflected light 1105 having the wavelength λ1, is driven to change the polarization state of the wavelength λ1 to the polarization of another wavelength. Different from the state. The polarization direction of the polarizing element disposed in the vicinity of the reflective liquid crystal element array 1108 and on the reflection optical path side is determined so as to transmit only the light in the polarization state reflected in the specific region. Accordingly, only the light source light having the wavelength λ1 reaches the output optical system 1113 as the output light 1112, and the spectrum light source device functions as a light source that outputs light having only the selected wavelength λ1. Further, if the first region 1109 is divided into a plurality of regions in a direction orthogonal to the wavelength dispersion direction, the number of channels can be increased. In the figure, a state in which light source light having a wavelength λ1 is output to one channel corresponding to the left end is shown.

  Similarly, by driving a reflective liquid crystal element corresponding to the second region 1110 as the specific region and making the polarization state of the wavelength λ2 different from the polarization state of other wavelengths, it is possible to output light of only the wavelength λ2. If the reflective liquid crystal element corresponding to the third region 1111 is driven as the specific region and the polarization state of the wavelength λ3 is different from the polarization state of other wavelengths, the light of only the wavelength λ3 can be output. Thus, the spectrum light source device can independently output light of an arbitrary wavelength to a plurality of channels according to the region selected by the reflective liquid crystal element array 1108.

  FIG. 2 is a conceptual diagram illustrating the principle of outputting a wavelength of λ1 in the spectrum light source device according to the second layout. The light source 1201 emits light source light 1210 over a predetermined wavelength region. Here, white light is emitted. The light source light 1210 forms an irradiation region 1211 that irradiates light in a planar region that is a reflection surface on the reflective liquid crystal element array 1202.

  The reflective liquid crystal element array 1202 is a device similar to the reflective liquid crystal element array 1108 described above. In FIG. 2, the control unit drives the reflective liquid crystal element belonging to the first region 1203 having a strip shape in the row direction, and changes the polarization state of the light source light 1210 irradiated to a part of the first region 1203. This is different from the polarization state of the light source light 1210 irradiated to other regions. The polarization direction of the polarizing element disposed in the vicinity of the reflective liquid crystal element array 1202 and on the reflection optical path side is determined so as to transmit only the light in the polarization state reflected in the specific region. Accordingly, only the light source light reflected by a part of the first region 1203 is incident on the light receiving surface of the diffraction grating 1206 at the first angle as the white reflected light 1213.

  The diffraction grating 1206 is the same element as the diffraction grating 1104 described above. Therefore, when the white reflected light 1213 is incident on the diffraction grating 1206, it is diffracted on the surface thereof and reflected as diffracted light having a characteristic wavelength in the direction corresponding to the reflection angle. For example, the incident light is dispersed so as to include diffracted light 1223 having a wavelength λ1 in the red region, diffracted light 1224 having a wavelength λ2 in the green region, and diffracted light 1225 having a wavelength λ3 in the blue region.

  The diffracted light reflected and dispersed by the diffraction grating 1206 is directed toward the slit 1207. At this time, the slit 1207 is positioned relative to the diffraction grating 1206 and has a fixed slit opening. Therefore, only the diffracted light having a specific wavelength among the diffracted light can pass through the slit opening. In FIG. 2, the diffracted light 1223 having the wavelength λ1 can pass through the slit opening.

  The output optical system provided in the spectrum light source device is positioned relative to the slit 1207 and installed. Specifically, the diffracted light passing through the slit opening of the slit 1207 is most preferably installed so as to enter the output optical system. For example, it is preferable that the diffracted light is incident perpendicular to the incident surface of the output optical system and near the center.

  Next, a case where output light having a wavelength of λ2 different from λ1 is output will be described. FIG. 3 is a conceptual diagram illustrating the principle of outputting a wavelength of λ2 in the spectrum light source device according to the second layout. The same elements as those in FIG. 2 are denoted by the same reference numerals and description thereof is omitted.

  In the case of outputting output light having a wavelength of λ2, the control unit drives a reflective liquid crystal element belonging to a part of the second region 1204 which is a strip shape in the row direction, and irradiates the second region 1204. The polarization state of the light source light 1210 is different from the polarization state of the light source light 1210 irradiated to other regions. The polarization state of the selected specific region is the same whether a partial region of the first region 1203 is selected or a partial region of the second region 1204 is selected. Therefore, here, only the light source light reflected by a part of the second region 1204 passes through the polarizing element as white reflected light 1214. The white reflected light 1214 transmitted through the polarizing element is incident on the light receiving surface of the diffraction grating 1206 at the second angle.

  The diffraction grating 1206 is positioned relative to the reflective liquid crystal element array 1202. Therefore, the white reflected light 1214 enters the reflecting surface of the diffraction grating 1206 in the same manner as the white reflected light 1213, but the incident angle is different. That is, the light is incident on the light receiving surface of the diffraction grating 1206 at a second angle instead of the first angle. As described above, the groove shape on the surface of the diffraction grating 1206 is such that the wavelength in the reflection direction is defined according to the reflection angle with respect to the incident angle of the incident light incident from the direction of the reflective liquid crystal element array 1202. As a result, the diffractive action of the white reflected light 1214 is shifted in comparison with the case of the white reflected light 1213 because the incident angle is different.

  The slit 1207 is positioned relative to the diffraction grating 1206, and the diffracted light that can pass through the slit opening is only that reflected at a predetermined angle with respect to the diffraction grating 1206. In the case of FIG. 2, since the direction of dispersion is shifted compared to the case of FIG. 1, the diffracted light 1233 with the wavelength λ1 in the red region, the diffracted light 1234 with the wavelength λ2 in the green region, and the diffracted light with the wavelength λ3 in the blue region. Of 1235, only the diffracted light 1234 passes through the slit opening of the slit 1207, and diffracted light of other wavelengths is blocked by the slit 1207.

  In other words, the first region 1203 is defined as the corresponding region of the reflective liquid crystal element array 1202 in which the output light having the wavelength λ1 is output from the slit opening of the slit 1207, and similarly, the second region corresponding to the wavelength λ2 is the second. Region 1204 is defined. Therefore, since the wavelength of the output light to be output corresponds to the strip region of the reflective liquid crystal element array 1202, the control unit drives and controls the reflective liquid crystal element in the corresponding strip region, so that output light of an arbitrary wavelength can be obtained. Can be output. Further, if the corresponding wavelength region is divided into a plurality of regions in the direction orthogonal to the chromatic dispersion direction, the number of channels can be increased. FIG. 2 shows a state in which the output light having the wavelength λ1 is output from the first channel corresponding to the right end, and FIG. 3 shows a state in which the output light having the wavelength λ2 is output from the third channel corresponding to the left end.

  Furthermore, in the second layout, the diffracted light passing through the slit opening of the slit 1207 is at a constant angle regardless of the output light of any wavelength, so that the diffracted light is input to the output optical system. Ideally incident. If the diffracted light can be incident perpendicularly to the incident surface of the output optical system and in the vicinity of the center, the output light of the spectrum light source device is less likely to have uneven wavelength distribution angles and uneven color distribution, which is uneven intensity distribution depending on the wavelength.

  A specific embodiment to which the principle described so far is applied will be described below with reference to the drawings.

Example 1
FIG. 4 is a schematic configuration diagram of the multi-channel spectrum light source apparatus according to the first embodiment. This embodiment conforms to the first layout described above. The light source 101 is a xenon lamp, and includes a concave mirror 1012 that projects an image of the arc 1011, an aperture stop 1013, and a light source positive lens 1014. The wavelength distribution in the visible light range emitted by the xenon lamp is close to the wavelength distribution of sunlight. The heat ray reflective filter 102 is installed according to the amount of heat generated by the light source 101 or the like. In particular, when the output light does not require a heat ray wavelength region, a heat ray reflection filter 102 having a predetermined spectral characteristic is installed to reduce the heat load of the subsequent optical system and the like. The light source 101 and the heat ray reflective filter 102 constitute the light source unit 1.

  The slit 301 includes a slit opening that can change the slit width by mechanical driving or the like. The arc 1011 forms an image across the maximum slit width of the slit 301. The first positive lens system 302 collimates the divergent light beam from the slit 301. The collimated light beam is linearly polarized by passing through the first polarizing filter 201. The direction of linearly polarized light of the first polarizing filter 201 is set in accordance with the direction of transmission through the polarizing beam splitter 202, and the light beam that has passed through the first polarizing filter 201 is transmitted through the polarizing beam splitter 202. The first polarizing filter 201 is not an essential element, but if the first polarizing filter 201 is installed, high-purity linearly polarized light can be created over a wide wavelength range by the action of the polarizing beam splitter 202. There is a slight amount of polarized light component in the direction orthogonal to the polarization direction transmitted through the first polarizing filter 201 as leakage light. Most of the leaked light component cannot be transmitted through the polarization beam splitter 202 but is reflected and absorbed by the trap 204.

  The light beam that has passed through the polarizing beam splitter 202 passes through the second positive lens system 303 to form an image of the slit 301. A stray light blocking diaphragm 304 is installed at the image plane position. That is, the surface of the slit 301 and the surface of the stray light blocking diaphragm 304 are in the relationship between the object plane and the image plane. The stray light blocking diaphragm 304 includes a rectangular opening in which an image of the slit 301 is not formed even when the slit width of the slit 301 is maximum. Although the stray light blocking stop 304 is not an essential element, it has a function of removing stray light and improves the S / N ratio of output light.

  Next, the divergent light beam from the stray light blocking diaphragm 304 is collimated by the third positive lens system 305 and guided to the diffraction grating 306. The divergent light beam reaching the diffraction grating 306 is diffracted on the surface thereof, and is reflected and dispersed as diffracted light having a specific wavelength in the direction corresponding to the reflection angle. As the diffraction grating 306, for example, a reflection type planar grating is used. The reflected and dispersed light beam passes through the fourth positive lens system 307 to form a spectrum image of the light source light on the light receiving surface 401 of the reflective liquid crystal element array 4. The formed spectrum image is also an image of the slit 301.

  The slit 301, the first positive lens system 302, the second positive lens system 303, the stray light blocking diaphragm 304, the third positive lens system 305, the diffraction grating 306, and the fourth positive lens system 307 constitute the wavelength dispersion system 3. The wavelength dispersion system 3 is optically designed so that astigmatism falls within a predetermined range, and has a predetermined resolution performance not only in the wavelength dispersion direction but also in a direction orthogonal thereto. If an optical system is configured using a refractive lens, it is relatively easy to keep astigmatism within a predetermined range. As an example of the wavelength dispersion element, in addition to the reflection type planar grating, other types of gratings such as a transmission type can be used, and a wavelength dispersion prism can also be used.

  The reflective liquid crystal element array 4 is arranged such that the light receiving surface 401 is the spectrum image plane of the wavelength dispersion system 3. The driver 5 drives the plurality of reflective liquid crystal elements included in the unit wavelength region and the region corresponding to the output channel in accordance with an instruction from the control unit. Specifically, the column direction along the arrow 402 corresponds to the wavelength dispersion direction, and each region corresponds to a unit wavelength region. The direction along the arrow 403, which is the direction orthogonal to the chromatic dispersion direction, corresponds to the output channel to be output. In the figure, it is shown that the area is defined in a 4 × 4 matrix shape. For example, unit wavelengths whose center wavelengths are λ1, λ2, λ3, and λ4 in the direction of the arrow 402 in order from the left column to the right column. The first channel 701, the second channel 702, the third channel 703, and the fourth channel 704, which will be described later, correspond in the direction of the arrow 403 in order from the upper row to the lower row. Therefore, the driver 5 drives a plurality of reflective liquid crystal elements included in a plurality of regions corresponding to the output channels on the light receiving surface 401 so that desired spectrum light is output for each output channel.

  Each of the plurality of reflective liquid crystal elements included in the selected region is made elliptically polarized by independently providing retardation to the incident linearly polarized light by driving the driver 5. The light beam reflected by the reflective liquid crystal element array 4 again enters the wavelength dispersion system 3 and is subjected to a multiplexing action, and forms a slit 301 image in the stray light blocking diaphragm 304 again. Next, the light is collimated by the second positive lens system 303 and enters the polarization beam splitter 202.

  Only the linearly polarized light component in the direction reflected by the polarization beam splitter 202 goes to the output positive lens system 6 through the second polarizing filter 203. The light beam reflected by the specific area selected on the light receiving surface 401 of the reflective liquid crystal element array 4 is elliptically polarized, and when incident on the polarization beam splitter 202, polarized light components orthogonal to each other at a predetermined ratio are reflected light. And transmitted light. Accordingly, the transmitted light component of the light beam reflected by the specific region and the light beam reflected by the region other than the specific region are transmitted through the polarization beam splitter 202 and again to the light source unit 1 via the first polarization filter 201. Return. The first polarizing filter 201, the polarizing beam splitter 202, the second polarizing filter 203, and the trap 204 constitute the polarization branching optical system 2. As shown in the figure, the polarization branching optical system 2 is in a relationship included in the wavelength dispersion system 3.

  The light beam that has passed through the output positive lens system 6 forms an image of the slit 301 on its image plane, which is also a conjugate image of the light receiving surface 401. Therefore, on this surface, the light beam having the selected unit wavelength is output as output light to the selected channel position. A plurality of output optical transmission devices are installed according to this channel. In the figure, each of a first channel 701, a second channel 702, a third channel 703, and a fourth channel 704 is an output optical transmission device and constitutes an output optical system 7. For example, a liquid light guide is employed as the output light transmission device. The liquid light guide has the property of being homogenized and output from the other end while the light beam input to one end is repeatedly reflected inside. Moreover, since it is flexible, it is preferable when the output light is guided to the irradiation target. The chromatic dispersion system 3 is optically designed so that astigmatism is within a predetermined range, and only reflected light from a region on the light receiving surface 401 is incident on each channel, and crosstalk occurs. It is considered not to occur.

  FIG. 5 is a diagram illustrating an imaging relationship in the optical system of the multi-channel spectrum light source device according to the first embodiment. As shown in the figure, the output light emitted as the arc 1011 image reaches the output optical system 7 in order of incidence of the slit 301, the stray light blocking stop 304, the light receiving surface 401, the stray light blocking stop 304, and the output optical system 7. It can be seen that the images are formed immediately before each end face.

  FIG. 6 is a diagram illustrating how the chief rays pass through the light flux channels of the multi-channel spectrum light source apparatus according to the first embodiment. The figure shows, as a representative example, a chief ray of a light beam that passes through the aperture center of the aperture stop 1013 as a principal ray and is condensed at the center of each channel of the output optical system 7. As can be seen, the optical system is designed so that each principal ray converges on the polarization beam splitter 202 and the diffraction grating 306 in both the forward path and the return path in the optical path that reciprocates between the polarization branching optical system 2 and the wavelength dispersion system 3. ing. Further, the optical design is such that any principal ray of incident light and reflected light with respect to the light receiving surface 401 is perpendicular to the light receiving surface 401. Of course, it is desirable that the incident light principal ray in the reflective liquid crystal element is perpendicular to the liquid crystal surface. In addition, it is designed such that the principal rays of each other are parallel when entering the output optical system 7. Accordingly, each of the output optical transmission devices is arranged in parallel.

  The multi-channel spectrum apparatus configured as described above can obtain a plurality of independent output channels with one apparatus. Therefore, for example, it is possible to easily create colors having slightly different values on a chromaticity diagram, for example, using only one device, and to confirm the difference visually.

(Example 2)
FIG. 7 is a schematic configuration diagram of a multi-channel spectrum light source apparatus according to the second embodiment. This embodiment conforms to the second layout described above. The light source unit 1 includes a light source 101 and a heat ray reflective filter 102 as in the first embodiment. An image of the xenon lamp arc 1011 is formed on the incident end face of the rod glass 801, and is output from the exit end face to the illumination optical system 802. The rod glass 801 has, for example, a quadrangular prism shape, and has an effect of making the light intensity distribution of light passing through the inside uniform. As a material of the rod glass 801, quartz glass excellent in heat resistance and transmittance is suitable.

  The light beam emitted from the illumination optical system 802 travels toward the reflective liquid crystal element array 4. The illumination optical system 802 includes a first group optical system 8021, an aperture stop 8022, and a second group optical system 8023, and is optically designed to be telecentric with respect to the light receiving surface 401 of the reflective liquid crystal element array 4. . The rod glass 801 and the illumination optical system 802 constitute a uniform optical system 8.

  Between the illumination optical system 802 and the light receiving surface 401, a first polarizing filter 201 and a polarizing beam splitter 202 are installed in order of the optical path, and the light incident on the light receiving surface 401 is converted into linearly polarized light in a predetermined direction. The first polarizing filter 201 is not an essential element, but if the first polarizing filter 201 is installed, high-purity linearly polarized light can be created over a wide wavelength range by the action of the polarizing beam splitter 202. There is a slight amount of polarized light component in the direction orthogonal to the polarization direction transmitted through the first polarizing filter 201 as leakage light. Most of the leaked light component cannot be transmitted through the polarization beam splitter 202 but is reflected and absorbed by the trap 204.

  In the reflective liquid crystal element array 4, the light receiving surface 401 receives a light beam transmitted through the polarization beam splitter 202. The luminous flux at this stage has not been split yet, and is white light. The driver 5 drives the plurality of reflective liquid crystal elements included in the unit wavelength region and the region corresponding to the output channel in accordance with an instruction from the control unit. Specifically, the column direction along the arrow 402 corresponds to the wavelength dispersion direction, and each region corresponds to a unit wavelength region. The direction along the arrow 403, which is the direction orthogonal to the chromatic dispersion direction, corresponds to the output channel to be output. In the figure, it is shown that the area is defined in a 4 × 4 matrix shape. For example, unit wavelengths whose center wavelengths are λ1, λ2, λ3, and λ4 in the direction of the arrow 402 in order from the left column to the right column. Corresponding to the region, the first channel 701, the second channel 702, the third channel 703, and the fourth channel 704 correspond in the direction of the arrow 403 in order from the upper row to the lower row. Accordingly, the driver 5 drives a plurality of reflective liquid crystal elements included in a plurality of regions corresponding to the output channels on the light receiving surface 401 so that desired spectrum light is output for each output channel.

  Each of the plurality of reflective liquid crystal elements included in the selected region is made elliptically polarized by independently providing retardation to the incident linearly polarized light by driving the driver 5. The light beam reflected by the reflective liquid crystal element array 4 enters the polarization beam splitter 202 again.

  Only the linearly polarized light component in the direction reflected by the polarization beam splitter 202 goes to the output positive lens system 6 through the second polarizing filter 203. The light beam reflected by the specific area selected on the light receiving surface 401 of the reflective liquid crystal element array 4 is elliptically polarized, and when incident on the polarization beam splitter 202, polarized light components orthogonal to each other at a predetermined ratio are reflected light. And transmitted light. Accordingly, the transmitted light component of the light beam reflected by the specific region and the light beam reflected by the region other than the specific region are transmitted through the polarization beam splitter 202 and again to the light source unit 1 via the first polarization filter 201. Return. The first polarizing filter 201, the polarizing beam splitter 202, the second polarizing filter 203, and the trap 204 constitute the polarization branching optical system 2.

  The light beam transmitted through the second polarizing filter 203 is collimated by the fourth positive lens system 307 and enters the diffraction grating 306. The divergent light beam reaching the diffraction grating 306 is diffracted on the surface thereof, and is reflected and dispersed as diffracted light having a specific wavelength in the direction corresponding to the reflection angle. As the diffraction grating 306, for example, a reflection type planar grating is used. The reflected and dispersed light beam passes through the third positive lens system 305 to form a spectrum image of the light source light in the slit 301. By the action of the third positive lens system 305 and the fourth positive lens system 307, the slit 301 surface and the light receiving surface 401 are in a conjugate relationship. Therefore, when viewed from the slit 301 side, a wavelength dispersion image of the slit 301 is formed on the light receiving surface 401, but the wavelength light forming the image of the slit 301 at the reflection position among the light beams reflected by the light receiving surface 401. It can be said that only can pass through the slit opening of the slit 301.

  The slit 301, the third positive lens system 305, the fourth positive lens system 307, and the diffraction grating 306 constitute the wavelength dispersion system 3. The wavelength dispersion system 3 is optically designed so that astigmatism falls within a predetermined range, and has a predetermined resolution performance not only in the wavelength dispersion direction but also in a direction orthogonal thereto. If an optical system is configured using a refractive lens, it is relatively easy to keep astigmatism within a predetermined range. As an example of the wavelength dispersion element, in addition to the reflection type planar grating, other types of gratings such as a transmission type can be used, and a wavelength dispersion prism can also be used.

  Further, a conjugate image of the slit 301 is formed by the output positive lens system 6. The output positive lens system 6 forms an image of the slit 301 in a telecentric manner. The image plane of the output positive lens system 6 is also a conjugate image of the light receiving surface 401. Therefore, on this surface, the light beam having the selected unit wavelength is output as output light to the selected channel position. A plurality of output optical transmission devices are installed according to this channel. In the figure, each of a first channel 701, a second channel 702, a third channel 703, and a fourth channel 704 is an output optical transmission device and constitutes an output optical system 7. For example, a liquid light guide is employed as the output light transmission device. The liquid light guide has the property of being homogenized and output from the other end while the light beam input to one end is repeatedly reflected inside. Moreover, since it is flexible, it is preferable when the output light is guided to the irradiation target. The chromatic dispersion system 3 is optically designed so that astigmatism is within a predetermined range, and only reflected light from a region on the light receiving surface 401 is incident on each channel, and crosstalk occurs. It is considered not to occur.

  FIG. 8 is a diagram illustrating an imaging relationship in the optical system of the multi-channel spectrum light source device according to the second embodiment. As shown in the figure, the output light emitted from the light source 101 forms an image on each of the light receiving surface 401, the slit 301, and the output optical system 7 immediately before the incident end surface by the time it reaches the output optical system 7. I understand.

  FIG. 9 is a diagram illustrating a principal beam passing state of each light beam channel of the multi-channel spectrum light source device according to the second embodiment. The figure shows, as a representative example, a chief ray of a light beam that passes through the aperture center of the aperture stop 1013 as a principal ray and is condensed at the center of each channel of the output optical system 7. As can be seen from the drawing, in the polarization splitting optical system 2, the respective principal rays are parallel to the optical axis, and the principal rays of the incident light and the reflected light with respect to the light receiving surface 401 are perpendicular to the light receiving surface 401. Is designed. Of course, it is desirable that the incident light principal ray in the reflective liquid crystal element is perpendicular to the liquid crystal surface. In addition, it is designed such that the principal rays of each other are parallel when entering the output optical system 7. Accordingly, each of the output optical transmission devices is arranged in parallel.

  The multi-channel spectrum apparatus configured as described above can obtain a plurality of independent output channels with one apparatus. Therefore, for example, it is possible to easily create colors having slightly different values on a chromaticity diagram, for example, using only one device, and to confirm the difference visually. Further, this layout is more preferable because the diffracted light is incident on the incident surface of the output optical system 7 perpendicularly and near the center.

  In the above embodiment, the reflective liquid crystal element array 4 is used as the modulation element. The reflective liquid crystal element array 4 controls the ratio of the orthogonal component of the reflected light incident on the polarization beam splitter 202 by controlling individual reflective liquid crystal elements included in a strip region corresponding to a certain unit wavelength region and channel. The light intensity can be adjusted by control. That is, if the orthogonal linearly polarized light components are increased so as to be reflected more by the polarization beam splitter 202, the output light intensity increases. Such a method is called a gradation modulation method. The light intensity of the output light can be adjusted by adjusting the orthogonal component ratio over the entire specific region by the gradation modulation method.

  The light intensity adjustment includes a time modulation method and an area modulation method in addition to the gradation modulation method described above. In the time modulation method, reflection liquid crystal elements included in a strip region corresponding to a certain unit wavelength region and channel are subjected to elliptical polarization by providing retardation to linearly polarized light incident within a unit time. Is repeated at a predetermined ratio to adjust the output light intensity. That is, the ratio of the orthogonal components of the reflected light incident on the polarizing beam splitter 202 is changed by continuous driving of the individual reflective liquid crystal elements.

  In the area modulation method, the number of reflective liquid crystal elements included in a strip area corresponding to a certain unit wavelength region and channel is changed between an element that makes an incident linearly polarized light and makes it elliptically polarized, and a device that does not. This adjusts the output light intensity. That is, the ratio of the orthogonal components of the reflected light incident on the polarizing beam splitter 202 is changed according to the area ratio of the reflective liquid crystal element that provides retardation. In the multi-channel spectrum devices of the first embodiment and the second embodiment using the reflective liquid crystal element array 4, relatively good results are obtained in the gradation modulation method and the time modulation method.

(Example 3)
FIG. 10 is a schematic configuration diagram of a multi-channel spectrum light source apparatus according to the third embodiment. In this embodiment, a micromirror array 9 is used instead of the reflective liquid crystal element array 4 in the second embodiment shown in FIG. The micromirror array 9 can be similarly applied in that the light source light that irradiates the light receiving surface of the modulation element is selected two-dimensionally along the arrows 902 and 903. The optical system is the same as the second embodiment shown in FIG. 7 except that the polarization splitting optical system 2 is eliminated.

  For the light amount modulation, a time modulation method is adopted. That is, when light amount modulation is performed for a unit wavelength region of a certain output channel, a plurality of micromirrors existing in a region on the micromirror array light receiving surface 901 corresponding to the unit wavelength region of the output channel are driven at the same time. Specifically, it is alternately directed to the two directions of the output optical path side and the discard optical path side, and the integrated value of the time directed to the output optical path side within a predetermined unit time and the time directed to the discard optical path side By adjusting the ratio with the integral value, the output amount of the wavelength light corresponding to the rectangular aperture image is controlled. According to this method, the light amount attenuation modulation in the region on the light receiving surface 901 of the micromirror array is made uniform, and it is difficult to cause a wavelength difference in the light intensity distribution on the output channel entrance aperture surface.

  In addition, the light intensity of the output light can be adjusted by the area modulation method. In the case of the area modulation method, micromirrors included in a certain unit wavelength region and channel are output by changing the number of angles set in the direction of the output optical system 7 and the number of angles set in the waste optical path side. Adjust the light intensity. That is, the ratio of the reflected light reflected to the output optical system 7 is changed according to the area ratio of the micromirror. However, the time modulation method is preferable in that the light amount attenuation modulation in the region on the micromirror array light receiving surface 901 is made more uniform, and the difference in wavelength of the light intensity distribution on the output channel incident aperture surface is less likely to occur. .

Example 4
FIG. 11 is a schematic configuration diagram of a multi-channel spectrum light source device according to the fourth embodiment. In this embodiment, a transmissive liquid crystal element array 41 is used instead of the reflective liquid crystal element array 4 in the second embodiment shown in FIG. The transmissive liquid crystal element array 41 can be similarly applied in that the light source light for irradiating the light receiving surface of the modulation element is selected two-dimensionally. The transmissive liquid crystal element array 41 includes a plurality of transmissive liquid crystal elements arranged two-dimensionally, and each liquid crystal element has an independent amount of retardation given to transmitted light via the driver 5 by the control unit. Controlled to change. The optical system is the same as the second embodiment shown in FIG. 7 except that the polarization splitting optical system 2 is eliminated.

  When the transmissive liquid crystal element array 41 is used, the third polarizing filter 414 is provided before and after the transmissive liquid crystal element array 41 in place of the polarization branching optical system 2 that is installed when the reflective liquid crystal element array 4 is used. And a fourth polarizing filter 415 is provided. The light source light from the homogenizing optical system 8 is linearly polarized by the third polarizing filter 414 and then enters the transmissive liquid crystal element array 41. In the transmitted light that is transmitted through the transmissive liquid crystal element array 41 and is elliptically deflected, only the linearly polarized component that can pass through the fourth polarizing filter 415 is projected in the direction of the wavelength dispersion system 3.

  The driver 5 drives the plurality of transmissive liquid crystal elements included in the unit wavelength region and the region corresponding to the output channel in accordance with an instruction from the control unit. Specifically, the column direction along the arrow 412 corresponds to the wavelength dispersion direction, and each region corresponds to a unit wavelength region. A direction along arrow 413 that is a direction orthogonal to the chromatic dispersion direction corresponds to an output channel to be output. In the figure, it is shown that the area is defined in a 4 × 4 matrix, but for example, unit wavelengths whose center wavelengths are λ1, λ2, λ3, and λ4 in the direction of the arrow 412 in order from the left column to the right column. Corresponding to the region, the first channel 701, the second channel 702, the third channel 703, and the fourth channel 704 correspond in the direction of the arrow 413 in order from the upper row to the lower row. Therefore, the driver 5 drives a plurality of transmissive liquid crystal elements included in a plurality of regions corresponding to the output channels on the light receiving surface 411 so that desired spectrum light is output for each output channel. The modulation method is the same as that of the reflective liquid crystal element array 4.

  The multi-channel spectrum apparatus configured as described above can obtain a plurality of independent output channels with one apparatus. Therefore, for example, it is possible to easily create colors having slightly different values on a chromaticity diagram, for example, using only one device, and to confirm the difference visually.

  In each of the above embodiments, the reflective liquid crystal element array 4, the micromirror array 9, and the transmissive liquid crystal element array 41 are divided into 4 × 4 regions. For example, a mask for clearly dividing the divided area may be provided on the light receiving surface 401, the light receiving surface 901, or the light receiving surface 411. By providing such a mask, crosstalk can be avoided in the output optical system 7. The same effect can be obtained even if a dead zone for discarding the light source light is set in the element between the divided regions instead of providing a mask. That is, in the reflective liquid crystal element array 4 and the transmissive liquid crystal element array 41, a dead zone region that does not have the same polarization state as the polarization state of the specific region is provided at the boundary of the divided regions. In the case of the micromirror array 9, a dead zone region that does not have the micromirror angle of the specific region is provided at the boundary between the divided regions.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Light source part, 2 Polarization splitting optical system, 3 Wavelength dispersion system, 4 Reflective type liquid crystal element array, 5 Driver, 6 Output positive lens system, 7 Output optical system, 8 Uniformation optical system, 9 Micro mirror array, 41 Transmission type Liquid crystal element array, 101 light source, 102 heat ray reflective filter, 201 first polarizing filter, 202 polarizing beam splitter, 203 second polarizing filter, 204 trap, 301 slit, 302 first positive lens system, 303 second positive lens system, 304 Stray light blocking diaphragm, 305 third positive lens system, 306 diffraction grating, 307 fourth positive lens system, 401 light receiving surface, 402, 403 arrow, 411 light receiving surface, 412, 413 arrow, 414 third polarizing filter, 415 fourth polarized light Filter, 701 1st channel, 702 2nd channel, 703 3rd channel 704, fourth channel, 801 rod glass, 802 illumination optical system, 901 light receiving surface, 902, 903 arrow, 1011 arc, 1012 concave mirror, 1013 aperture stop, 1014 light source positive lens, 1101 irradiation area, 1102 slit, 1103 slit light DESCRIPTION OF SYMBOLS 1104 Diffraction grating, 1105 First reflected light, 1106 Second reflected light, 1107 Third reflected light, 1108 Reflective liquid crystal element array, 1109 First region, 1110 Second region, 1111 Third region, 1112 Output light, 1113 Output optical system, 1201 light source, 1202 reflective liquid crystal element array, 1203 first region, 1204 second region, 1206 diffraction grating, 1207 slit, 1210 light source light, 1211 irradiation region, 1213, 1214 white reflected light, 1223, 1224 1225 diffracted light, 1233,1234,1235 diffracted light, 8021 first group optical system, 8022 aperture stop, 8023 second group optical system

Claims (20)

A light source that emits light source light over a predetermined wavelength region;
A slit that allows a portion of the light source light to pass through;
A wavelength dispersion element for wavelength-dispersing the light source light;
In the planar region irradiated with the light source light, one or more specific regions selected from a plurality of divided regions that are two-dimensionally divided along a direction corresponding to the wavelength dispersion direction and a direction perpendicular thereto. A modulation element that reflects or transmits the light source light differently from other regions;
A multi-channel spectrum light source device comprising: a control unit that guides the light source light to a plurality of output regions corresponding to the orthogonal directions by controlling the specific region of the modulation element. The modulation element is a reflective liquid crystal element array that reflects and modulates the light source light so that the polarization state of the specific region is different from the polarization state of other regions,
2. The multi-channel spectrum light source according to claim 1, further comprising a polarization beam splitter that reflects a polarization component in a predetermined direction and transmits a polarization component in another direction out of the light source light reflected by the reflective liquid crystal element array. apparatus.   The control unit according to claim 2, wherein when the intensity of the output light is adjusted, the control unit performs control by adjusting a ratio of applying the modulation action per unit time in the specific region and a ratio of not giving the modulation action. Channel spectrum light source device.   The output optical transmission device provided with two or more back | latter stages rather than the reflective side of the said polarization beam splitter so that it may arrange | position corresponding to the direction orthogonal to the dispersion direction wavelength-dispersed by the said wavelength dispersion element. A multi-channel spectrum light source device according to claim 1.   The light source light emitted from the light source passes through the slit and the polarization beam splitter, is wavelength-dispersed by the wavelength dispersion element, is reflected by the reflective liquid crystal element array, and then passes again through the wavelength dispersion element. The light source light, the slit, the wavelength dispersion element, and the reflective liquid crystal so that the light source light that has reached the polarization beam splitter and reflected by the polarization beam splitter is incident on any of the output light transmission devices. The multi-channel spectrum light source apparatus according to claim 4, wherein an element array, the polarization beam splitter, and the output light transmission device are arranged.   The multi-channel spectrum light source device according to claim 5, further comprising a first polarizing filter that transmits only a linearly polarized light component in a predetermined direction of the light source light between the slit and the polarizing beam splitter.   7. The multi-channel spectrum light source device according to claim 5, further comprising a second polarizing filter that transmits only a linearly polarized light component in a predetermined direction of the light source light between the polarization beam splitter and the output light transmission device.   The light source light emitted from the light source passes through the polarization beam splitter, is reflected by the reflective liquid crystal element array, reaches the polarization beam splitter again, and is further reflected by the polarization beam splitter. Is wavelength-dispersed by the wavelength-dispersing element, and the light source light, the slit, and the wavelength so that a part of the wavelength-distributed light source light passes through the slit and enters one of the output light transmission devices. The multi-channel spectrum light source apparatus according to claim 4, wherein a dispersion element, the reflective liquid crystal element array, the polarization beam splitter, and the output light transmission device are arranged.   The multi-channel spectrum light source device according to claim 8, further comprising a first polarizing filter that transmits only a linearly polarized light component in a predetermined direction of the light source light between the light source and the polarization beam splitter.   The multi-channel spectrum light source device according to claim 8 or 9, further comprising a second polarizing filter that transmits only a linearly polarized light component in a predetermined direction of the light source light between the polarizing beam splitter and the wavelength dispersion element.   11. The multichannel spectrum light source device according to claim 2, further comprising a mask that divides the plurality of divided regions from each other in the vicinity of a light receiving surface of the reflective liquid crystal element array.   The multi-channel spectrum according to any one of claims 2 to 11, wherein the reflective liquid crystal element array includes a dead zone region that does not have the same polarization state as the polarization state of the specific region at a boundary of the plurality of divided regions. Light source device.   2. The multi-channel spectrum light source device according to claim 1, wherein the modulation element is a micromirror array that is set so that a micromirror angle of the specific region is different from a micromirror angle of another region.   The said control part, when adjusting the intensity | strength of output light, controls by adjusting the ratio per unit time set to the same angle as the micromirror angle of said other area | region in the said specific area | region. A multi-channel spectrum light source device according to claim 1.   The multi-channel spectrum light source device according to claim 13 or 14, further comprising a mask that divides the plurality of divided regions from each other in the vicinity of a light receiving surface of the micromirror array.   The multichannel spectrum light source device according to any one of claims 13 to 15, wherein the micromirror array includes a dead zone region that does not have a micromirror angle of the specific region at a boundary between the plurality of divided regions.   2. The multi-channel spectrum according to claim 1, wherein the modulation element is a transmissive liquid crystal element array that transmits the light source light with a modulation action so that a polarization state of the specific region is different from a polarization state of another region. Light source device.   The control unit according to claim 17, wherein when the intensity of the output light is adjusted, the control is performed by adjusting a rate at which the modulation action per unit time is given and a rate at which the modulation effect is not given in the specific region. Channel spectrum light source device.   The multi-channel spectrum light source device according to claim 17 or 18, further comprising a mask that divides the plurality of divided regions from each other in the vicinity of a light receiving surface of the transmissive liquid crystal element array.   The multi-channel spectrum according to any one of claims 17 to 19, wherein the transmissive liquid crystal element array includes a dead band region that does not have the same polarization state as the polarization state of the specific region at a boundary between the plurality of divided regions. Light source device.

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