JP2008300106A - Lighting system, projector, and monitor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of effectively utilizing light advancing in a direction other than the direction of an illumination object from a diffractive optical element, stopping the emission of light at the occurrence of an abnormality of a light source, and supplying light having stable luminous energy, and a projector and a monitor device using the lighting system. <P>SOLUTION: This lighting system includes: the light source 12R emitting light; the diffractive optical element 13R diffracting the light from the light source 12R, and advancing the diffracted light to a lighting object; and a shade 21 arranged to be able to shade the light from the light source 12R. The shade 21 shades at least a part of the light from the light source 12R according to a detection result by a light detection part 23 detecting the light advancing in a direction other than the direction of the lighting object from the diffractive optical element 13R. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lighting device, a projector, and a monitor device, and more particularly to a technology of a lighting device using a laser light source.

  In recent years, a technique using a laser light source as a light source of a projector has been proposed. Laser light sources have been developed as light sources for projectors with higher output and more colors. Compared with UHP lamps conventionally used as projector light sources, laser light sources have advantages such as high color reproducibility, instant lighting, and long life. A diffractive optical element can be used in an illumination device that uses a laser light source. The diffractive optical element can simultaneously perform shaping and enlargement of the illumination area and equalization of the light amount distribution in the illumination area by diffracting the laser light. By adopting a configuration that fulfills a plurality of functions by the diffractive optical element, the illumination device can be configured with a small number of parts, and the optical system can be easily downsized and space-saving. For example, Patent Document 1 proposes a technique of an illumination device that uses a diffractive optical element.

JP 2007-33576 A

  When the zero-order light and the diffracted light are simultaneously incident on the illumination area, the zero-order light and the diffracted light may overlap to make only a part of the illumination area bright. On the other hand, by making the area other than the area where the zero-order light is incident an illumination area, it is easy to make the light quantity distribution uniform. For example, the diffractive optical element can be configured to form an illumination region using + 1st order diffracted light. It is extremely difficult for a diffractive optical element to have a configuration in which only desired diffracted light is emitted due to design convenience and manufacturing errors of the diffractive optical element. Even when the diffractive optical element forms an illumination region with + 1st order diffracted light, for example, zeroth order light and −1st order diffracted light are generated. Such light other than the desired diffracted light is usually shielded by the light absorbing member. In addition, assuming that the output of the laser light source has increased significantly due to some abnormality or the traveling direction of the laser light has shifted significantly, the lighting device should immediately stop emitting laser light in response to these abnormalities. Is desired. Furthermore, it is desirable that the illumination device can supply a stable amount of light regardless of fluctuations in the output of the laser light source. The present invention has been made in view of the above, and can effectively use light traveling in a direction other than the direction of the illumination target from the diffractive optical element, can stop light emission when an abnormality occurs in the light source unit, and It is an object of the present invention to provide an illumination device capable of supplying a stable amount of light, a projector using the illumination device, and a monitor device.

  In order to solve the above-described problems and achieve the object, an illumination device according to the present invention includes a light source unit that emits light, and a diffractive optical element that diffracts light from the light source unit and advances diffracted light toward an illumination target. And a shielding part provided so as to shield light from the light source part, and the shielding part is a detection result by a light detection part that detects light traveling in a direction other than the direction of the illumination target from the diffractive optical element. Accordingly, at least part of the light from the light source unit is shielded.

  By detecting the light traveling in a direction other than the direction of the illumination target by the light detection unit, the light traveling in the direction other than the direction of the illumination target can be effectively used. When the light intensity is significantly increased or the light traveling direction is shifted due to an abnormality in the light source unit, the detection result of the light detection unit varies. By driving the shielding unit according to the detection result, the lighting device can shield light when an abnormality occurs in the light source unit. Furthermore, the illumination device can adjust the amount of light by shielding part of the light from the light source unit against fluctuations in the output of the light source unit. As a result, it is possible to effectively use light traveling in a direction other than the direction of the illumination target from the diffractive optical element, stop the emission of light when an abnormality occurs in the light source unit, and supply a stable amount of light Can be obtained.

  Moreover, as a preferable aspect of the present invention, it is desirable that the light detection unit detects zero-order light traveling from the diffractive optical element in a direction other than the direction of the illumination target. Thereby, the zero order light traveling in a direction other than the direction of the illumination target from the diffractive optical element can be effectively used.

  As a preferred aspect of the present invention, it is desirable that the light detection unit detects diffracted light traveling in a direction other than the direction of the illumination target from the diffractive optical element. Thereby, diffracted light traveling in a direction other than the direction of the illumination target from the diffractive optical element can be effectively used.

  Moreover, as a preferable aspect of the present invention, it is desirable to have an abnormality notification unit that notifies the occurrence of abnormality in the light source unit according to the detection result by the light detection unit. Thereby, the situation which a malfunction reaches to the member and human body which comprise an illuminating device can further be suppressed.

  Moreover, as a preferable aspect of the present invention, it is desirable that the light detection unit detects a light amount distribution of light traveling in a direction other than the direction of the illumination target from the diffractive optical element. Thereby, it is possible to accurately detect the occurrence of an abnormality that shifts the direction of light.

  Furthermore, a projector according to the present invention includes the above-described illumination device, and displays an image using light from the illumination device. By using the lighting device, light can be used effectively, light emission can be stopped when an abnormality occurs in the light source unit, and a stable amount of light can be supplied. Accordingly, it is possible to obtain a projector that can effectively use light, can stop light emission when an abnormality occurs in the light source unit, and can display an image with stable brightness.

  Moreover, as a preferable aspect of the present invention, the lighting device includes a first lighting device that supplies first color light, a second lighting device that supplies second color light, and a third lighting device that supplies third color light, A first spatial light modulation device that modulates first color light from the first illumination device according to an image signal, and a second spatial light modulation that modulates second color light from the second illumination device according to an image signal Device, a third spatial light modulator that modulates third color light from the third illumination device according to an image signal, and first color light that travels in a direction other than the direction of the first spatial light modulator from the first illumination device Detecting second color light traveling in a direction other than the direction of the second spatial light modulator from the second illumination device and third color light traveling in a direction other than the direction of the third spatial light modulator from the third illumination device. It is desirable to have a light detection unit. By making it possible to detect the first color light, the second color light, and the third color light by the light detection unit, the projector can reduce the number of components compared to the case where the light detection unit is provided for each lighting device.

  Furthermore, a projector according to the present invention includes a lighting device having a light source unit that emits light, a diffractive optical element that diffracts light from the light source unit, and a space that modulates light from the lighting device according to an image signal. A spatial light modulator, and the spatial light modulator is controlled according to a detection result by a light detection unit that detects light traveling in a direction other than the direction of the spatial light modulator from the diffractive optical element. And By controlling the spatial light modulation device according to the detection result of the light detection unit, light can be shielded when there is an abnormality in the light source unit. In addition, a stable light amount can be obtained regardless of fluctuations in the output of the light source unit. Furthermore, a spatial light quantity change can be reduced. Accordingly, it is possible to obtain a projector that can effectively use light, can stop light emission when an abnormality occurs in the light source unit, and can display an image with stable brightness.

  As a preferred aspect of the present invention, it is desirable that the light detection unit detects zero-order light that travels in a direction other than the direction of the spatial light modulator from the diffractive optical element. Thereby, the zero order light traveling in a direction other than the direction of the illumination target from the diffractive optical element can be effectively used.

  As a preferred aspect of the present invention, it is desirable that the light detection unit detects diffracted light traveling in a direction other than the direction of the spatial light modulator from the diffractive optical element. Thereby, diffracted light traveling in a direction other than the direction of the illumination target from the diffractive optical element can be effectively used.

  Moreover, as a preferable aspect of the present invention, it is desirable that the light detection unit detects a light amount distribution of light traveling in a direction other than the direction of the spatial light modulator from the diffractive optical element. Thereby, control for reducing the spatial light quantity change is possible.

  Moreover, as a preferable aspect of the present invention, the lighting device includes a first lighting device that supplies first color light, a second lighting device that supplies second color light, and a third lighting device that supplies third color light, The spatial light modulation device includes: a first spatial light modulation device that modulates the first color light from the first illumination device according to an image signal; and a second color light from the second illumination device that is modulated according to the image signal. And a third spatial light modulation device that modulates the third color light from the third illumination device according to the image signal, and the light detection unit is connected to the first space from the first illumination device. First color light traveling in a direction other than the direction of the light modulation device, second color light traveling in a direction other than the direction of the second spatial light modulation device from the second illumination device, and third spatial light modulation device from the third illumination device It is desirable to detect the third color light traveling in a direction other than the first direction. By making it possible to detect the first color light, the second color light, and the third color light by the light detection unit, the projector can reduce the number of components compared to the case where the light detection unit is provided for each lighting device.

  Moreover, as a preferable aspect of the present invention, it is desirable to have a color separation unit that separates the first color light, the second color light, and the third color light traveling to the light detection unit. By using the color separation unit, the amount of light for each color light can be detected. Thereby, the spatial light modulator for each color light can be controlled based on the detection result for each color light.

  Furthermore, a monitor device according to the present invention includes the above-described illumination device and an imaging unit that captures an image of a subject illuminated by light from the illumination device. By using the lighting device, light can be used effectively, light emission can be stopped when an abnormality occurs in the light source unit, and a stable amount of light can be supplied. Accordingly, it is possible to obtain a monitor device that can effectively use light, can stop emission of light when an abnormality occurs in the light source unit, and can capture a subject with stable brightness.

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

  FIG. 1 shows a schematic top configuration of a projector 10 according to a first embodiment of the invention. The projector 10 is a front projection type projector that appreciates an image by projecting light onto a screen (not shown) and observing the light reflected by the screen. The projector 10 includes a red (R) light illumination device 11R, a green (G) light illumination device 11G, and a blue (B) light illumination device 11B. The R light illumination device 11 </ b> R is a first illumination device that supplies R light that is first color light. The G light illumination device 11G is a second illumination device that supplies G light that is second color light. The B light illumination device 11 </ b> B is a third illumination device that supplies B light that is third color light. The projector 10 displays an image using the R light from the R light illumination device 11R, the G light from the G light illumination device 11G, and the B light from the B light illumination device 11B.

  The R light illumination device 11R includes an R light source unit 12R. The R light source unit 12R is a light source unit that emits laser light, and includes, for example, a semiconductor laser. The diffractive optical element 13R diffracts the R light from the R light source unit 12R and advances the diffracted light to the R light spatial light modulator 15R that is the illumination target of the R light illumination device 11R. The diffractive optical element 13R forms a rectangular illumination pattern with a uniform light amount distribution on the incident surface of the R light spatial light modulator 15R. The diffractive optical element 13R performs shaping and enlargement of the illumination area, and uniformizing the light amount distribution in the illumination area. The field lens 14 collimates the light from the diffractive optical element 13R. The R light spatial light modulation device 15R is a first spatial light modulation device that modulates R light according to an image signal, and is a transmissive liquid crystal display device. The R light from the R light spatial light modulator 15 </ b> R enters the cross dichroic prism 16.

  The G light illumination device 11G includes a G light source unit 12G. The G light source unit 12G is a light source unit that emits laser light, and includes, for example, a semiconductor laser. The diffractive optical element 13G diffracts the G light from the G light source unit 12G and advances the diffracted light to the G light spatial light modulator 15G that is the illumination target of the G light illumination device 11G. The diffractive optical element 13G forms a rectangular illumination pattern with a uniform light amount distribution on the incident surface of the G light spatial light modulator 15G. The diffractive optical element 13G performs shaping and enlargement of the illumination area and uniformizing the light amount distribution in the illumination area. The field lens 14 collimates the light from the diffractive optical element 13G. The G light spatial light modulation device 15G is a second spatial light modulation device that modulates G light according to an image signal, and is a transmissive liquid crystal display device. The G light from the G light spatial light modulator 15G is incident on a different surface of the cross dichroic prism 16 from the surface on which the R light is incident.

  The B light illumination device 11B includes a B light source 12B. The B light source unit 12B is a light source unit that emits laser light, and includes, for example, a semiconductor laser. The diffractive optical element 13B diffracts the B light from the B light source unit 12B and advances the diffracted light to the B light spatial light modulator 15B that is the illumination target of the B light illumination device 11B. The diffractive optical element 13B forms an illumination pattern with a rectangular shape and a uniform light amount distribution on the incident surface of the B light spatial light modulator 15B. The diffractive optical element 13B performs shaping and enlargement of the illumination area and equalizing the light amount distribution in the illumination area. The field lens 14 collimates the light from the diffractive optical element 13B. The B light spatial light modulation device 15B is a third spatial light modulation device that modulates B light according to an image signal, and is a transmissive liquid crystal display device. The B light from the B light spatial light modulator 15B is incident on a surface of the cross dichroic prism 16 different from the surface on which the R light is incident and the surface on which the G light is incident.

  As the diffractive optical element, for example, a computer generated hologram (CGH) can be used. As the transmissive liquid crystal display device, for example, a high temperature polysilicon TFT liquid crystal panel (HTPS) can be used. Each of the color light source units 12R, 12G, and 12B may be configured to use a wavelength conversion element that converts the wavelength of the laser light from the semiconductor laser, for example, a second harmonic generation (SHG) element. Each of the color light source units 12R, 12G, and 12B may include a semiconductor laser pumped solid state (DPSS) laser, a solid laser, a liquid laser, and a gas laser instead of the semiconductor laser.

  The cross dichroic prism 16 has two dichroic films 17 and 18 arranged substantially orthogonal to each other. The first dichroic film 17 reflects R light and transmits G light and B light. The second dichroic film 18 reflects B light and transmits R light and G light. The cross dichroic prism 16 combines the R light, the G light, and the B light incident from different directions and emits them in the direction of the projection lens 19. The projection lens 19 projects the light combined by the cross dichroic prism 16 toward the screen.

  FIG. 2 shows a schematic side configuration of the R light illumination device 11R. FIG. 3 illustrates the traveling direction of light emitted from the diffractive optical element 13R. FIG. 4 illustrates an illumination pattern formed by the diffractive optical element 13R. The diffractive optical element 13R uses the + 1st order diffracted light L + 1 indicated by a solid line to form an illumination pattern having a rectangular shape and a uniform light amount distribution. In addition, the diffractive optical element 13R generates zero-order light L0 indicated by a one-dot chain line and −1st-order diffracted light L-1 indicated by a broken line. Zero-order light is light that is not diffracted by the diffractive optical element 13R but is transmitted through the diffractive optical element 13R as it is. The −1st order diffracted light L-1 is diffracted light that travels substantially symmetrically with the + 1st order diffracted light L + 1 with respect to the zeroth order light L0.

  As shown in FIG. 2, the R light spatial light modulator 15R is provided at a position where the + 1st-order diffracted light L + 1 collimated by the field lens 14 is incident. The zero-order light L0 and the −1st-order diffracted light L-1 from the diffractive optical element 13R travel in directions other than the direction of the R light spatial light modulator 15R. By causing the zero-order light L0 to travel in a direction other than the direction of the spatial light modulator for R light 15R, unevenness such that only the portion where the zero-order light L0 and the + 1st-order diffracted light L + 1 overlap in the illumination region becomes brighter is generated. This makes it easy to make the light quantity distribution uniform.

  The photodiode (PD) 23 is provided at a position where the zero-order light L0 from the diffractive optical element 13R is incident. The PD 23 is a light detection unit that detects the zero-order light L0 that travels in a direction other than the direction of the R light spatial light modulation device 15R from the diffractive optical element 13R. At a position where the −1st order diffracted light L-1 from the diffractive optical element 13R is incident, a light absorbing portion 22 that absorbs the −1st order diffracted light L-1 is provided. The light absorption part 22 is comprised using the light absorptive resin member, for example.

  The shielding unit 21 is provided between the R light source unit 12R and the diffractive optical element 13R so as to shield light from the R light source unit 12R. The shielding unit 21 shields light from the R light source unit 12 </ b> R according to the detection result by the PD 23. For example, the shielding unit 21 can be freely opened and closed by adopting the same configuration as a diaphragm used in an optical device. In addition, the shielding unit 21 may use a mechanism capable of switching between passage and shielding of light by moving the light shielding member. The light emitting diode (LED) 24 is an abnormality notification unit that notifies the occurrence of abnormality in the R light source unit 12R by emitting light according to the detection result by the PD 23. The G light illumination device 11G and the B light illumination device 11B have the same configuration as the R light illumination device 11R.

  FIG. 5 shows a block configuration for controlling the projector 10. The control unit 34 includes a CPU (Central Processing Unit) 35 and a memory 36, and functions as a computer. The memory 36 includes a flash ROM (Read Only Memory) or the like. The control unit 34 controls the driving of the projector 10 by operating the CPU 35 according to the control program stored in the memory 36. The image signal conversion unit 31 converts an image signal input from an external device or the like into a format that can be processed by the image signal processing unit 32. The image signal converter 31 converts the image signal based on the control by the controller 34. The image signal converter 31 converts, for example, an image signal input as an analog signal into a digital signal.

  The image signal processing unit 32 performs various image quality adjustment processes on the image signal converted by the image signal conversion unit 31. The processing for image quality adjustment is, for example, resolution conversion for converting the resolution so as to match the number of pixels of the color light spatial light modulators 15R, 15G, and 15B, brightness adjustment, contrast adjustment, sharpness adjustment, and the like. The spatial light modulation driver 33 drives the color light spatial light modulators 15R, 15G, and 15B based on the image signal processed by the image signal processor 32. The light source driving unit 37 drives the light source units 12R, 12G, and 12B for each color light based on the control by the control unit 34.

  Further, the control unit 34 controls the shielding unit 21 and the LED 24 based on the detection result by the PD 23. When each of the color light source units 12R, 12G, and 12B is operating normally, the PD 23 detects zero-order light with a light amount within a predetermined range. When the PD 23 detects a laser beam having a predetermined amount of light, the shielding unit 21 is fully opened and allows the laser beam to pass through, as shown in FIG. While the laser light of a predetermined amount of light is detected, the light from each color light source unit 12R, 12G, 12B is emitted without being shielded by the shielding unit 21. Further, the LED 24 keeps a light-off state.

  On the other hand, for example, when the PD 23 detects a laser beam with a light amount exceeding a predetermined range, the control unit 34 changes the shielding unit 21 to a closed state. As a result, the laser beams from the color light source units 12R, 12G, and 12B are shielded by the shielding unit 21. The projector 10 closes the shielding unit 21 of each color light illumination device 11R, 11G, 11B when a laser beam having a light amount exceeding a predetermined range is detected for at least one of the color light illumination devices 11R, 11G, 11B. Can be configured. Thereby, the projector 10 immediately stops the emission of laser light when an abnormality occurs in at least one of the light source units 12R, 12G, and 12B for each color light.

  The control unit 34 turns on the LED 24 when a laser beam having a light amount exceeding a predetermined range is detected. The user can recognize whether or not an abnormality has occurred in each of the color light source units 12R, 12G, and 12B, depending on whether or not the LED 24 is lit. The projector 10 can be configured to turn on the LED 24 when a laser beam having a light amount exceeding a predetermined range is detected for at least one of the illumination devices 11R, 11G, and 11B for each color light. Accordingly, the projector 10 immediately turns on the LED 24 when an abnormality occurs in at least one of the light source units 12R, 12G, and 12B for each color light.

  When the output of each of the color light source units 12R, 12G, and 12B is remarkably increased, it is necessary to reliably avoid a situation in which the projector 10 and the human body are damaged by a laser beam that is stronger than usual. When the amount of light detected by the PD 23 is remarkably increased, the laser beam is shielded by the shielding unit 21, so that the laser beam can be used for the occurrence of an abnormality that increases the output of the light source units 12 R, 12 G, and 12 B for each color light. Can be stopped. In addition, by notifying the user of the abnormality of the light source units 12R, 12G, and 12B for each color light by the LED 24, the user can take some measures for the abnormality at an early stage. Thereby, it is possible to further suppress the situation where the projector 10 and the human body are in trouble. The shielding unit 21 is preferably configured to be opened when current is supplied to the shielding unit 21 and to be closed when current supply is stopped. Thereby, it is possible to control the laser beam to be shielded against any trouble.

  In addition to the above, for example, even when the traveling direction of the laser light emitted from the light source units 12R, 12G, and 12B for each color light is significantly shifted, it is assumed that the projector 10 and the human body are in trouble. The fact that the traveling direction of the laser light has shifted significantly means that the amount of zero-order light detected by the PD 23 is significantly reduced even though the laser light is emitted from the color light source units 12R, 12G, and 12B. Can be recognized. When the zero-order light is not detected in the PD 23, the laser light is shielded by the shielding part 21, so that the advancing direction of the laser light from the light source parts 12R, 12G, 12B for each color light is significantly shifted. The laser light emission can be stopped with respect to the generation. Also in this case, by notifying the user of the abnormality of the light source units 12R, 12G, and 12B for each color light by the LED 24, it is possible to further suppress the situation in which the projector 10 and the human body are in trouble.

  The shielding unit 21 may be configured to adjust the amount of laser light by shielding part of the laser light from the light source units 12R, 12G, and 12B for each color light. The shielding unit 21 has a configuration similar to that of a diaphragm used in an optical device, so that the amount of laser light can be adjusted according to the size of the opening region. For example, when the amount of zero-order light detected by the PD 23 increases, the shielding unit 21 is controlled to narrow the opening area of the shielding unit 21 according to the amount of increase in the amount of zero-order light. By adjusting the amount of light in the shielding unit 21 according to the amount of zero-order light detected by the PD 23, a stable amount of laser light is supplied regardless of fluctuations in the output of the light source units 12R, 12G, and 12B for each color light. it can. The adjustment of the amount of laser light from each color light source unit 12R, 12G, 12B is performed for each color light using the PD 23 provided in each color light illumination device 11R, 11G, 11B.

  It is extremely difficult for a diffractive optical element to have a configuration in which only desired diffracted light is emitted due to design convenience and manufacturing errors of the diffractive optical element. When the PD 23 detects laser light traveling in a direction other than the direction of the spatial light modulators 15R, 15G, and 15B for each color light, it travels in a direction other than the direction of the spatial light modulators 15R, 15G, and 15B for each color light. Laser light can be used effectively. As a result, it is possible to effectively use light traveling in a direction other than the direction of the illumination target from the diffractive optical element, to enable light emission to be stopped when an abnormality occurs in the light source unit, and to display a stable brightness image. Play.

  The abnormality notifying unit is not limited to the LED 24, and other light emitting means for generating light may be used. The abnormality notification unit is not limited to the light emitting unit. The abnormality notification unit may be, for example, a sound generation unit that generates sound, such as a buzzer or a speaker. The sound generation means notifies the abnormality by generating sound. Further, the abnormality generating unit may have both a light emitting unit and a sound generating unit.

  The projector 10 may detect the −1st order diffracted light L-1 by the PD 23 or may detect higher order diffracted light such as second order diffracted light. In this embodiment, the emission of light is stopped not only when there is an abnormality in the light source unit or when there is an output change, but also when there is an abnormality such as misalignment, dropout or breakage of the diffractive optical elements 13R, 13G, 13B. be able to. Furthermore, the projector 10 of the present embodiment may be configured to control the spatial light modulation device in accordance with the detection result by the PD 23.

  FIG. 6 illustrates a configuration for controlling the spatial light modulation device in accordance with the detection result by the PD 23. Here, the R light illumination device 11 </ b> R is illustrated and described. In the block configuration shown in FIG. 5, the control unit 34 controls the image signal processing unit 32 based on the detection result by the PD 23. The image signal processing unit 32 converts the image signal in accordance with control by the control unit 34.

  When the amount of light detected by the PD 23 is remarkably increased, or when the traveling direction of the laser light is significantly shifted, each color light spatial light modulator 15R, 15G, 15B performs image signal processing according to the control of the control unit 34. The emission of the modulated light is stopped by the processing of the unit 32. Further, when there is a change in the output of each color light source unit 12R, 12G, 12B, each color light spatial light modulator 15R, 15G, 15B is adjusted according to the amount of zero-order light detected by the PD 23. Emits modulated light of high intensity. Also in this case, the emission of light can be stopped when an abnormality occurs in the light source unit, and a stable amount of light can be supplied.

  FIG. 7 illustrates a projector according to a second embodiment of the present invention, and illustrates a schematic side configuration of the R light illumination device 40R. The present embodiment is characterized by having a CMOS (Complementary Metal Oxide Semiconductor) sensor 42 for detecting the −1st order diffracted light L-1. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The illumination device for G light and the illumination device for B light have the same configuration as the illumination device for R light 40R. The CMOS sensor 42 is a light detection unit that detects −1st-order diffracted light L-1 that is diffracted light traveling in a direction other than the direction of the R light spatial light modulator 15R from the diffractive optical element 13R.

  A field lens 41 is provided in the optical path between the diffractive optical element 13R and the CMOS sensor. The field lens 41 collects the −1st order diffracted light L-1 from the diffractive optical element 13R and makes it incident on the CMOS sensor. The CMOS sensor 42 has a plurality of light receiving elements (not shown). A light absorbing portion 43 that absorbs the zero-order light L0 is provided at a position where the zero-order light L0 from the diffractive optical element 13R is incident. The light absorption part 43 is comprised using the light absorptive resin member, for example. Note that the field lens 41 may be omitted as long as the minus first-order diffracted light L-1 from the diffractive optical element 13R can be incident on the CMOS sensor.

  FIG. 8 shows a block configuration for controlling the projector. The CMOS sensor 42 detects the light amount distribution of the −1st order diffracted light L-1. The control unit 34 controls the image signal processing unit 32 according to the light amount distribution of the −1st order diffracted light L-1 detected by the CMOS sensor 42. In the example of the light amount distribution shown in FIG. 9, it is assumed that the colored portion is darker than the white portion. Due to the characteristics of the diffractive optical elements 13R, 13G, and 13B, the light amount distribution of the + 1st order diffracted light L + 1 is substantially symmetrical to the light amount distribution of the −1st order diffracted light L−1 with respect to the zeroth order light L0. For this reason, the light quantity distribution of the + 1st order diffracted light L + 1 can be estimated by appropriately converting the light quantity distribution of the −1st order diffracted light L−1.

  The control unit 34 controls the image signal processing unit 32 according to the light amount distribution of the + 1st order diffracted light L + 1 estimated from the detection result by the CMOS sensor 42. Each of the color light spatial light modulators 15R, 15G, and 15B emits modulated light in which the spatial light quantity change is reduced by the processing of the image signal processing unit 32 according to the control of the control unit 34. For example, in the colored portion shown in FIG. 9, a spatial light amount change can be reduced by performing a process of increasing the light amount in accordance with the light amount difference from the white portion. The spatial light modulators 15R, 15G, and 15B for each color light are controlled for each color light by using a CMOS sensor 42 provided in each color light illumination device.

  In addition, when the traveling direction of the laser light emitted from each color light source unit 12R, 12G, 12B is significantly shifted, the light amount distribution of the −1st order diffracted light L-1 detected by the CMOS sensor 42 is changed. Can be recognized. The laser beam is shielded by the shielding unit 21 in accordance with the change in the light amount distribution of the −1st-order diffracted light L-1 detected by the CMOS sensor 42, so that the progress of the laser light from each color light source unit 12R, 12G, 12B. The laser light emission can be stopped in response to the occurrence of an abnormality that causes a significant shift in direction.

  The outputs of the color light source units 12R, 12G, and 12B are obtained by integrating the light amount values detected by the light receiving elements of the CMOS sensor 42. For example, the laser beam can be shielded by the shielding unit 21 when the integrated value exceeds a predetermined range. Thereby, it is possible to stop the emission of the laser light in response to the occurrence of an abnormality in which the light amount of the laser light from each color light source unit 12R, 12G, 12B is remarkably increased. In addition, the light quantity of the laser light can be adjusted by controlling the shielding unit 21 and the spatial light modulators 15R, 15G, and 15B for each color light with respect to the fluctuation of the integrated value. As described above, light can be used effectively, light emission can be stopped when an abnormality occurs in the light source unit, and an image with stable brightness can be displayed.

  FIG. 10 illustrates a projector according to a modification of the present embodiment, and shows a schematic side configuration of an R light illumination device 45R. The illumination device for G light and the illumination device for B light have the same configuration as the illumination device for R light 45R. The CMOS sensor 46 is provided in parallel with the R light spatial light modulator 15R. The CMOS sensor 46 has a rectangular shape substantially the same size as the spatial light modulator 15R for R light. The minus first-order diffracted light L-1 from the diffractive optical element 13R is collimated by the field lens 14 and enters the CMOS sensor 46.

  The field lens 14 has a function of causing the + 1st order diffracted light L + 1 to enter the spatial light modulator 15R for R light and a function of causing the −1st order diffracted light L-1 to enter the CMOS sensor 46. In the present modification, the field lens 41 in the configuration shown in FIG. 7 can be eliminated, so that the number of parts of the projector can be reduced. In addition, since the CMOS sensor 46 having substantially the same size as the spatial light modulators 15R, 15G, and 15B can be used, the light amount distribution can be detected with high accuracy.

  In the present embodiment, in addition to the case where there is an abnormality in the light source section or an output change, for example, in the case where there is a light amount unevenness due to a manufacturing error or a positional deviation of the diffractive optical elements 13R, 13G, 13B, Thus, unevenness in the amount of light can be corrected. Further, when a plurality of laser light sources are used, even when there is unevenness in the amount of light due to fluctuations in the output balance between the laser light sources, the unevenness in the amount of light can be corrected by controlling the spatial light modulator.

  In the present embodiment, the projector is not limited to the case where the first order diffracted light is detected by the CMOS sensors 42 and 46, and may detect higher order diffracted light such as second order diffracted light. The light detection unit is not limited to the CMOS sensors 42 and 46. The light detection unit may be an image pickup device other than the CMOS sensors 42 and 46, for example, a CCD (Charge Coupled Device) sensor. The projector may detect zero-order light by a CMOS sensor or a CCD sensor that is an image sensor.

  FIG. 11 is a schematic diagram illustrating a schematic configuration of the projector 50 according to the third embodiment of the invention. The projector 50 according to the present embodiment includes a PD 55 that detects zero-order light L0 from each color light illumination device 51R, 51G, 51B. The same parts as those in the first and second embodiments are denoted by the same reference numerals, and redundant description is omitted. Similar to the projector 10 shown in FIG. 1, the projector 50 is configured to synthesize each color light using a cross dichroic prism. Here, in order to briefly explain the behavior of light from each of the diffractive optical elements 13R, 13G, and 13B, the color light illumination devices 51R, 51G, and 51B are shown in parallel. The diffractive optical elements 13R, 13G, and 13B advance the zero-order light L0R, L0G, and L0B in the direction along the paper surface, whereas the diffractive optical elements 13R, 13G, and 13B advance the + 1st-order diffracted light L + 1 to the front side of the paper surface. The color light spatial light modulators 15R, 15G, and 15B are provided on the front side of the sheet with respect to the surface on which the zero-order lights L0R, L0G, and L0B travel.

  The reflection mirror 52 is provided at a position where the zero-order light L0R from the diffractive optical element 13R of the R light illumination device 51R is incident. The reflection mirror 52 reflects the zero-order light L0R and bends the optical path. The first dichroic mirror 53 is provided at a position where the zero-order light L0R from the reflection mirror 52 and the zero-order light L0G from the diffractive optical element 13G of the G light illumination device 51G are incident. The first dichroic mirror 53 transmits R light and reflects G light. The first dichroic mirror 53 reflects the zero-order light L0G from the G light illumination device 51G, bends the optical path, and transmits the zero-order light L0R from the reflection mirror 52, thereby transmitting the zero-order lights L0R and L0G. Synthesize.

  The second dichroic mirror 54 is provided at a position where the zero-order lights L0R and L0G from the first dichroic mirror 53 and the zero-order light L0B from the diffractive optical element 13B of the illuminating device 51B for B light are incident. The second dichroic mirror 54 transmits R light and G light and reflects B light. The second dichroic mirror 54 reflects zero-order light L0B from the B light illumination device 51B, bends the optical path, and transmits zero-order light L0R and L0G from the first dichroic mirror 53, thereby transmitting zero-order light. Synthesize L0R, L0G, and L0B. The zero-order lights L0R, L0G, and L0B synthesized in this way enter the PD 55. The configuration for synthesizing the zero-order lights L0R, L0G, and L0B is not limited to that described in this embodiment, and may be changed as appropriate.

  The PD 55 is a light detection unit that detects zero-order light L0R that is R light, zero-order light L0G that is G light, and zero-order light L0B that is B light. The shielding unit 21 provided in each color light illumination device 51R, 51G, 51B shields the laser light from each color light source unit 12R, 12G, 12B according to the detection result by the PD 55. The LED 24 is turned on according to the detection result by the PD 55 to notify the occurrence of an abnormality in each color light source unit 12R, 12G, 12B. By enabling the PD 55 to detect R light, G light, and B light, the projector 50 can reduce the number of components compared to the case where a light detection unit is provided for each lighting device. The projector 50 can reduce the manufacturing cost by reducing the number of parts.

  FIG. 12 is a schematic diagram illustrating a schematic configuration of a projector 60 according to a modification of the present embodiment. The projector 60 according to this modification includes a CMOS sensor 66 that detects −1st-order diffracted lights L-1R, L-1G, and L-1B from the illumination devices for color light 61R, 61G, and 61B. The diffractive optical elements 13R, 13G, and 13B advance the + 1st order diffracted light L + 1 toward the front side of the paper, and advance the −1st order diffracted lights L-1R, L-1G, and L-1B toward the back side of the paper.

  The reflection mirror 62 is provided at a position where the −1st order diffracted light L-1R having passed through the field lens 14 from the diffractive optical element 13R of the R light illumination device 61R is incident. The reflection mirror 62 reflects the −1st order diffracted light L-1R and bends the optical path. The first dichroic mirror 63 is at a position where the −1st order diffracted light L-1R from the reflection mirror 62 and the −1st order diffracted light L-1G from the diffractive optical element 13G of the G light illumination device 61G through the field lens 14 are incident. Is provided. The first dichroic mirror 63 transmits R light and reflects G light. The first dichroic mirror 63 reflects the −1st order diffracted light L-1G from the G light illumination device 61G, bends the optical path, and transmits the −1st order diffracted light L-1R from the reflection mirror 62, so that − First order diffracted light L-1R and L-1G are synthesized.

  The second dichroic mirror 64 is the −1st order diffracted light L-1R, L-1G from the first dichroic mirror 63, and the −1st order diffracted light L− that has passed through the field lens 14 from the diffractive optical element 13B of the B light illumination device 61B. It is provided at a position where 1B is incident. The second dichroic mirror 64 transmits R light and G light and reflects B light. The second dichroic mirror 64 reflects the −1st order diffracted light L-1B from the B light illumination device 61B, bends the optical path, and also receives the −1st order diffracted lights L-1R and L-1G from the first dichroic mirror 63. By transmitting the light, first-order diffracted light L-1R, L-1G, and L-1B are synthesized. The first-order diffracted lights L-1R, L-1G, and L-1B synthesized in this way enter the color wheel 65.

  The color wheel 65 is a color separation unit that separates R light, G light, and B light traveling from the second dichroic mirror 64 to the CMOS sensor 66. The color wheel 65 has a circular shape in which a dichroic film that transmits only R light, a dichroic film that transmits only G light, and a dichroic film that transmits only B light are combined. The color wheel 65 rotates about an axis substantially parallel to the light beams of the −1st order diffracted lights L-1R, L-1G, and L-1B. At the same time as rotating the color wheel 65, the −1st order diffracted lights L-1R, L-1G, and L-1B are made incident on the color wheel 65 by causing the −1st order diffracted lights L-1R, L-1G, and L-1B to enter. Separate by time division.

  The CMOS sensor 66 is a light detection unit that sequentially detects −1st order diffracted light L-1R that is R light, −1st order diffracted light L-1G that is G light, and −1st order diffracted light L-1B that is B light. The spatial light modulator for R light 15R is controlled according to the detection result of the −1st order diffracted light L-1R in the CMOS sensor 66. The spatial light modulation device 15G for G light is controlled according to the detection result of the −1st order diffracted light L-1G in the CMOS sensor 66. The spatial light modulation device 15B for B light is controlled according to the detection result of the −1st order diffracted light L-1B in the CMOS sensor 66. Further, the shielding unit 21 provided in each color light illumination device 61R, 61G, 61B shields the laser light from each color light source unit 12R, 12G, 12B according to the detection result by the CMOS sensor 66. The LED 24 is turned on according to the detection result by the CMOS sensor 66, thereby notifying the occurrence of an abnormality in each color light source unit 12R, 12G, 12B.

  FIG. 13 shows a block configuration for controlling the projector 60. The color wheel 65 rotates at a predetermined number of revolutions according to the control of the control unit 34. The CMOS sensor 66 sequentially detects the −1st order diffracted lights L-1R, L-1G, and L-1B transmitted through the color wheel 65. The control unit 34 controls the image signal processing unit 32 according to the detection result by the CMOS sensor 66. Each of the color light spatial light modulators 15R, 15G, and 15B emits modulated light in which the spatial light quantity change is reduced by the processing of the image signal processing unit 32 according to the control of the control unit 34. Thereby, based on the detection result for every color light, each color light spatial light modulator 15R, 15G, 15B is controllable. Further, the shielding unit 21 and the LED 24 are controlled according to the detection results of the −1st order diffracted lights L-1R, L-1G, and L-1B by the CMOS sensor 66 as in the case of the second embodiment.

  The color separation unit is not limited to the color wheel 65, and is, for example, a color filter in which a dichroic film that transmits only R light, a dichroic film that transmits only G light, and a dichroic film that transmits only B light are arranged in parallel. Also good. In this case, the CMOS sensor 66 can detect each color light based on the detection result in the light receiving element in the portion corresponding to each dichroic film. The projector 60 may combine a PD that is a light detection unit and a color separation unit. Further, when the light sources 12R, 12G, and 12B are sequentially turned on, the projector 60 can sequentially detect each color light by the CMOS sensor 66 without using a color separation unit.

  The projector described in each embodiment is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The projector is not limited to a configuration including a spatial light modulator for each color light. The projector may be configured to modulate two or three or more color lights with one spatial light modulator. The projector is not limited to the case where the spatial light modulator is used. The projector may be a slide projector that uses a slide having image information. The projector may be a so-called rear projector that supplies light to one surface of the screen and observes an image by observing light emitted from the other surface of the screen.

  FIG. 14 shows a schematic configuration of a monitor device 70 according to the fourth embodiment of the present invention. The monitor device 70 includes a device main body 71 and an optical transmission unit 72. The apparatus main body 71 includes an illumination device 73 similar to each color light illumination device 11R, 11G, 11B (see FIG. 1) of the first embodiment. A duplicate description with the first embodiment is omitted. The light transmission unit 72 includes two light guides 75 and 76. A diffusion plate 77 and an imaging lens 78 are provided at the end of the light transmission unit 72 on the subject (not shown) side. The first light guide 75 transmits light from the illumination device 73 to the subject. The diffusion plate 77 is provided on the emission side of the first light guide 75. The light propagated through the first light guide 75 is diffused on the subject side by passing through the diffusion plate 77.

  The second light guide 76 transmits light from the subject to the camera 74. The imaging lens 78 is provided on the incident side of the second light guide 76. The imaging lens 78 condenses light from the subject onto the incident surface of the second light guide 76. The light from the subject enters the second light guide 76 through the imaging lens 78, then propagates through the second light guide 76 and enters the camera 74.

  As the first light guide 75 and the second light guide 76, a bundle of many optical fibers can be used. By using an optical fiber, it is possible to transmit laser light far away. The camera 74 is provided in the apparatus main body 71. The camera 74 is an imaging unit that captures an image of a subject illuminated by light from the illumination device 73. By making the light incident from the second light guide 76 enter the camera 74, the subject can be imaged by the camera 74.

  By using the illumination devices 73 similar to the illumination devices 11R, 11G, and 11B for the respective color lights in the first embodiment, light can be used effectively, light emission can be stopped when an abnormality occurs in the light source unit, and stable. A light amount of light can be supplied. Thus, the light can be used effectively, the light emission can be stopped when an abnormality occurs in the light source unit, and an object with stable brightness can be imaged. In addition, the illuminating device 73 is good also as a structure similar to any illuminating device demonstrated in each said Example.

  The illumination device of the present invention is not limited to the case where a semiconductor laser is used as a laser light source, and a solid laser, a liquid laser, a gas laser, or the like may be used. Moreover, an illuminating device is not restricted to the case where a laser light source is used for a light source part. For example, the illumination device may be configured to use a solid light source such as an LED as the light source unit. The illuminating device of this invention is good also as a structure which controls a light source part according to the detection result by a light detection part. For example, the illumination device can be configured to stop the emission of light from the light source unit when an abnormality occurs in the light source unit, or to perform a feedback control of the light source unit with respect to fluctuations in the output of the light source unit. Accordingly, it is possible to stop the emission of light when an abnormality occurs in the light source unit, and it is possible to display an image with more stable brightness. The illumination device of the present invention is not limited to being applied to a projector or a monitor device. The illumination device of the present invention may be used in an optical system such as an exposure device or a laser processing device that performs exposure using laser light.

  As described above, the illumination device according to the present invention is useful when used in a projector or a monitor device.

1 is a diagram illustrating a schematic top configuration of a projector according to a first embodiment of the invention. The figure which shows the side surface schematic structure of the illuminating device for R light. The figure explaining the advancing direction of the light inject | emitted from a diffractive optical element. The figure explaining the illumination pattern formed of a diffractive optical element. The figure which shows the block structure for controlling a projector. The figure explaining the structure for controlling a spatial light modulation device. FIG. 6 is a diagram illustrating a projector according to a second embodiment of the invention. The figure which shows the block structure for controlling a projector. The figure explaining the relationship between the light quantity distribution of + 1st order diffracted light, and the light quantity distribution of -1st order diffracted light. FIG. 10 is a diagram for explaining a projector according to a modification of the second embodiment. FIG. 9 is a schematic diagram illustrating a schematic configuration of a projector according to a third embodiment of the invention. FIG. 10 is a schematic diagram illustrating a schematic configuration of a projector according to a modification example of Embodiment 3. The figure which shows the block structure for controlling a projector. The figure which shows schematic structure of the monitor apparatus which concerns on Example 4 of this invention.

Explanation of symbols

  10 projector, 11R R light illumination device, 11G G light illumination device, 11B B light illumination device, 12R R light source unit, 12G G light source unit, 12B B light source unit, 13R, 13G, 13B Diffractive optical element, 14 field lens, spatial light modulator for 15R R light, spatial light modulator for 15G G light, spatial light modulator for 15B B light, 16 cross dichroic prism, 17 first dichroic film, 18 second dichroic Film, 19 Projection lens, 21 Shielding part, 22 Light absorption part, 23 PD, 31 Image signal conversion part, 32 Image signal processing part, 33 Spatial light modulation driving part, 34 Control part, 35 CPU, 36 Memory, 37 Light source driving Part, 40R R light illumination device, 41 field lens, 42 CMOS sensor, 43 light absorption part, 45R R Illumination device, 46 CMOS sensor, 50 projector, 51R R light illumination device, 51G G light illumination device, 51B B light illumination device, 52 reflection mirror, 53 first dichroic mirror, 54 second dichroic mirror, 55 PD , 60 projector, 61R R light illumination device, 61G G light illumination device, 61B B light illumination device, 62 reflection mirror, 63 first dichroic mirror, 64 second dichroic mirror, 65 color wheel, 66 CMOS sensor, 70 Monitor device 71 Device body 72 Light transmission unit 73 Illumination device 74 Camera 75 First light guide 76 Second light guide 77 Diffuser plate 78 Imaging lens

Claims (14)

A light source that emits light;
A diffractive optical element that diffracts light from the light source unit and advances diffracted light to an illumination target;
A shielding part provided to shield light from the light source part,
The shielding unit shields at least a part of light from the light source unit according to a detection result by a light detection unit that detects light traveling in a direction other than the direction of the illumination target from the diffractive optical element. A lighting device.   The illumination device according to claim 1, wherein the light detection unit detects zero-order light traveling in a direction other than the direction of the illumination target from the diffractive optical element.   The illumination device according to claim 1, wherein the light detection unit detects diffracted light traveling in a direction other than the direction of the illumination target from the diffractive optical element.   The illuminating device according to claim 1, further comprising: an abnormality notifying unit that notifies the occurrence of an abnormality in the light source unit according to a detection result by the light detecting unit.   5. The illumination device according to claim 1, wherein the light detection unit detects a light amount distribution of light traveling in a direction other than the direction of the illumination target from the diffractive optical element.   A projector comprising the illumination device according to claim 1, wherein an image is displayed using light from the illumination device. The lighting device includes a first lighting device that supplies first color light, a second lighting device that supplies second color light, and a third lighting device that supplies third color light,
A first spatial light modulator that modulates the first color light from the first illumination device according to an image signal;
A second spatial light modulator that modulates the second color light from the second illumination device according to an image signal;
A third spatial light modulator that modulates the third color light from the third illumination device according to an image signal;
The first color light traveling in a direction other than the direction of the first spatial light modulator from the first illumination device, and the second color traveling in a direction other than the direction of the second spatial light modulator from the second illumination device. The projector according to claim 6, further comprising: a color detection unit configured to detect color light and the third color light traveling in a direction other than the direction of the third spatial light modulator from the third illumination device. . A lighting device comprising: a light source unit that emits light; and a diffractive optical element that diffracts light from the light source unit;
A spatial light modulator that modulates light from the illumination device according to an image signal,
The projector is characterized in that the spatial light modulation device is controlled according to a detection result by a light detection unit that detects light traveling in a direction other than the direction of the spatial light modulation device from the diffractive optical element.   The projector according to claim 8, wherein the light detection unit detects zero-order light traveling in a direction other than the direction of the spatial light modulator from the diffractive optical element.   The projector according to claim 8, wherein the light detection unit detects diffracted light traveling in a direction other than the direction of the spatial light modulator from the diffractive optical element.   The projector according to claim 8, wherein the light detection unit detects a light amount distribution of light traveling from the diffractive optical element in a direction other than a direction of the spatial light modulator. . The lighting device includes a first lighting device that supplies first color light, a second lighting device that supplies second color light, and a third lighting device that supplies third color light,
The spatial light modulator is a first spatial light modulator that modulates the first color light from the first illumination device according to an image signal, and the second color light from the second illumination device according to an image signal. A second spatial light modulation device that modulates the third color light from the third illumination device, and a third spatial light modulation device that modulates the third color light according to an image signal,
The light detecting unit travels in a direction other than the direction of the first spatial light modulator from the first lighting device, and in a direction other than the direction of the second spatial light modulator from the second lighting device. The second color light that travels to the position and the third color light that travels in a direction other than the direction of the third spatial light modulator from the third illumination device are detected. The projector according to one item.   The projector according to claim 7, further comprising a color separation unit that separates the first color light, the second color light, and the third color light traveling to the light detection unit. The lighting device according to any one of claims 1 to 5,
And an imaging unit that images a subject illuminated by light from the illumination device.

Images