JP2009098325A - Projection system - Google Patents

Abstract

To provide a projection system capable of preventing occurrence of projection light in the direction of an observer and reducing occurrence of defects.
A projector that projects projection light, a screen on which projection light projected by the projector is incident, a detection light source section that supplies detection light traveling toward the screen, and a detection light source. And a camera 32 that is a light detection unit that detects the detection light supplied from the unit 31 and reflected by the screen 12, and the screen 12 reflects the detection light supplied from the light source unit 31 for detection. Are provided in a specific pattern, and the projector 11 outputs the projection light according to the result of collating the pattern recognized by the light detection unit by detecting the detection light with the pattern of the detection light reflection unit. Control.
[Selection] Figure 2

Description

  The present invention relates to a projection system, and more particularly to a technology of a projection system having a projector and a screen.

  In recent years, projectors have been increasing in size and brightness of images to be displayed. Further, the projector is required to be downsized. The projector can be easily carried by downsizing. A projector that is easy to carry is assumed to be used in various situations in various places, for example, for home use. In this case, it is expected that the projection light that should be projected onto the screen from the projector is incident on an object other than the screen. The strong projection light before being diffused by the screen may be adversely affected by being directly incident on the eyes of the observer. In view of this, the projector has taken measures to prevent the occurrence of problems that adversely affect the viewer. When a laser light source is used in place of a lamp such as an ultra-high pressure mercury lamp that has been conventionally used as a light source for a projector, it is necessary to take measures to prevent the occurrence of problems even at a low output. For example, Patent Document 1 proposes a technique using a sensor that senses an object existing between a screen and a projection lens. By controlling the output of the projection light immediately according to the sensing of the object by the sensor, it is possible to prevent the occurrence of problems due to the observer entering.

JP 2002-6397 A

  If the projection light that is to be projected from the projector onto the screen is incident on a highly reflective member such as a mirror, strong projection light reflected by the highly reflective member may travel in the direction of the observer. In the technique of Patent Document 1, since the output of projection light is continued as usual unless an object is detected by the sensor, the direction of the observer when a highly reflective member is placed in front of the screen or instead of the screen. Strong projection light may travel. Thus, according to the conventional technique, there arises a problem that it may be difficult to prevent the situation in which the projected light travels in the direction of the observer. The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a projection system that can prevent a situation in which projection light travels in the direction of an observer and can reduce the occurrence of defects.

  In order to solve the above-described problems and achieve the object, a projection system according to the present invention includes a projector that projects projection light, a screen that receives projection light projected by the projector, and detection that proceeds toward the screen. A detection light source unit that supplies light; and a light detection unit that detects detection light supplied from the detection light source unit and reflected by the screen. The screen reflects detection light supplied from the detection light source unit. The detection light reflecting part is provided in a specific pattern, and the projector projects according to the result of collating the pattern recognized by the light detection part by detecting the detection light and the pattern of the detection light reflecting part. It is characterized by controlling the output of light.

  The projector authenticates the screen by collating the pattern recognized by the detection light with the pattern of the detection light reflecting portion. The projector can recognize that the projection light is normally incident on the screen by judging that the pattern recognized by the detection light matches the pattern of the detection light reflecting portion and as a result of matching. When an abnormality occurs, for example, when a highly reflective member is placed instead of the screen, the pattern of the detection light and the pattern of the detection light reflecting portion do not match. For an anomaly in which an entering object such as an observer exists between the projector and the screen, the pattern of the detection light and the pattern of the detection light reflecting part do not coincide with each other in the portion corresponding to the shadow of the entering object. As described above, when the pattern recognized by the detection light does not match the pattern of the detection light reflecting portion, it is determined that an abnormality has occurred, and the output of the projection light is stopped. By stopping the output of the projection light when the screen is not authenticated by the projector, it is possible to prevent the projection light from traveling in the direction of the observer. As a result, it is possible to obtain a projection system that can prevent a situation in which projection light travels in the direction of the observer and can reduce the occurrence of defects.

  In a preferred embodiment of the present invention, the detection light is desirably light other than visible light. Thereby, the screen can be authenticated without hindering the display using the projection light.

  As a preferable aspect of the present invention, it is desirable that the light source unit for detection is disposed at a position facing the screen in the projector. Thereby, the detection light from the light source part for a detection can be advanced toward a screen by simple structure.

  Further, as a preferred aspect of the present invention, the projector includes a projection light source unit for projecting projection light, a light combining unit that combines light from the projection light source unit and detection light from the detection light source unit, It is desirable to have Thereby, the detection light from the light source part for a detection can be supplied to the whole irradiation area | region into which projection light enters.

  As a preferred aspect of the present invention, the projector includes a spatial light modulation device that modulates light from the projection light source unit according to an image signal, and the light combining unit includes a projection light source unit and a spatial light modulation device. It is desirable to arrange in the optical path between. Thereby, the light from the projection light source unit and the detection light from the detection light source unit can be synthesized.

  As a preferred aspect of the present invention, the projector includes a scanning unit that scans light according to an image signal from the projection light source unit, and the light combining unit is disposed in an optical path between the projection light source unit and the scanning unit. It is desirable that it is arranged. Thereby, the detection light from the light source part for a detection can be made to inject into the whole irradiation area | region into which projection light enters.

  Moreover, as a preferable aspect of the present invention, it is desirable that the detection light reflecting portion is provided in a specific pattern in substantially the entire irradiation area where the projection light is incident on the screen. Accordingly, it is possible to recognize with high accuracy the occurrence of an abnormality in which an entrance object such as an observer exists between the projector and the screen.

  Moreover, as a preferable aspect of the present invention, the screen has a detection light absorption unit that absorbs detection light, and the detection light absorption unit is a portion where the detection light reflection unit is provided in the irradiation region where the projection light is incident. It is desirable to be provided in the other part. Thereby, the detection light reflection part which makes a specific pattern can be obtained.

  As a preferred aspect of the present invention, the projector notifies the occurrence of abnormality according to the result of collating the pattern recognized by the light detection unit by detecting the detection light and the pattern of the detection light reflection unit. It is desirable to have an abnormality notification unit. This makes it possible for the user to clearly recognize that an abnormality has occurred and that the output of projection light has been stopped in response to the occurrence of the abnormality.

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

  FIG. 1 shows a schematic configuration of a projection system 10 according to Embodiment 1 of the present invention. The projection system 10 includes a projector 11 and a screen 12. The projector 11 is a front projection type projector that projects projection light onto a screen 12 and observes an image by observing light reflected by the screen 12. The projector 11 projects the projection light modulated according to the image signal onto the screen 12.

  FIG. 2 shows a schematic configuration of the projector 11. The lamp light source 20 supplies light including red light (R light), green light (G light), and blue light (B light). The lamp light source 20 is a projection light source unit for projecting projection light. As the lamp light source 20, for example, an ultra-high pressure mercury lamp, a metal halide lamp, a halogen lamp, or the like can be used. The first dichroic mirror 21 reflects B light and transmits R light and G light. The B light is reflected by the first dichroic mirror 21 to bend the optical path.

  The reflection mirror 22 reflects the B light from the first dichroic mirror 21. After the optical path is bent again by the reflection mirror 22, the B light enters the spatial light modulator for B light 23B. The B light spatial light modulation device 23B is a spatial light modulation device that modulates the B light according to an image signal. The B light modulated by the B light spatial light modulator 23 </ b> B enters the cross dichroic prism 24.

  The R light and G light transmitted through the first dichroic mirror 21 are incident on the second dichroic mirror 25. The second dichroic mirror 25 reflects G light and transmits R light. The G light is reflected by the second dichroic mirror 25 to bend the optical path, and then enters the G light spatial light modulator 23G. The G light spatial light modulation device 23G is a spatial light modulation device that modulates the G light according to an image signal. The G light modulated by the G light spatial light modulator 23G is incident on a different surface of the cross dichroic prism 24 from the surface on which the B light is incident.

  The R light that has passed through the second dichroic mirror 25 is reflected by the two reflecting mirrors 26 and 27 so that the optical path is bent, and then enters the R light spatial light modulator 23R. The spatial light modulator for R light 23R is a spatial light modulator that modulates R light according to an image signal. The R light modulated by the spatial light modulator for R light 23R is incident on a surface of the cross dichroic prism 24 that is different from both the surface on which the B light is incident and the surface on which the G light is incident. The housing 33 of the projector 11 accommodates each component provided in the optical path from the lamp light source 20 to the cross dichroic prism 24 inside.

  The cross dichroic prism 24 has two dichroic films 28 and 29 arranged substantially orthogonal to each other. The first dichroic film 28 reflects B light and transmits R light and G light. The second dichroic film 29 reflects R light and transmits G light and B light. The cross dichroic prism 24 combines R light, G light, and B light incident from different directions. The projection lens 30 projects the light synthesized by the cross dichroic prism 24. The R light spatial light modulation device 23R, the G light spatial light modulation device 23G, and the B light spatial light modulation device 23B are, for example, transmissive liquid crystal display devices. As the transmissive liquid crystal display device, for example, a high temperature polysilicon TFT liquid crystal panel (HTPS) can be used. The projector 11 may use an optical system for enlarging and shaping the irradiation area by the lamp light source 20 and making the light amount distribution uniform.

  The detection light source unit 31 and the camera 32 are provided in a position of the housing 33 that faces the screen 12. The detection light source unit 31 supplies detection light traveling toward the screen 12. The detection light is light other than visible light, for example, infrared light. The detection light source unit 31 is, for example, a light emitting diode (LED) that supplies infrared light. The camera 32 is a light detection unit that detects detection light supplied from the detection light source unit 31 and reflected by the screen 12. The camera 32 has a filter that blocks visible light and transmits infrared light. The camera 32 detects only the infrared light that has passed through the filter. The camera 32 includes a plurality of light receiving elements (not shown) that convert incident light into electronic signals. As the camera 32, for example, a CCD or a CMOS sensor can be used.

  The abnormality notification LED 34 is provided in the housing 33. The abnormality notification LED 34 functions as an abnormality notification unit that notifies the occurrence of an abnormality according to a result of collating a pattern recognized by the camera 32 by detecting detection light and a pattern of a detection light reflecting unit described later. The abnormality notification LED 34 is lit to notify the occurrence of abnormality. The abnormality notification LED 34 may be provided at any position of the housing 33. The detection light source unit 31 and the camera 32 may be at positions facing the screen 12 and are not limited to the illustrated positions.

  FIG. 3 illustrates the configuration of the screen 12. A detection light reflection unit 35 and a detection light absorption unit 36 are provided in the irradiation region of the screen 12 where the projection light from the projector 11 is incident. The detection light reflector 35 reflects the detection light supplied from the detection light source unit 31. The detection light absorption unit 36 absorbs the detection light supplied from the detection light source unit 31. Both the detection light reflection unit 35 and the detection light absorption unit 36 reflect visible light. The detection light absorber 36 is configured using a member that reflects visible light and absorbs infrared light. The detection light reflection unit 35 is configured using a member that reflects visible light and infrared light.

  The detection light reflection unit 35 and the detection light absorption unit 36 are provided in a specific pattern in which the detection light reflection unit 35 and the detection light absorption unit 36 each having a square shape are alternately arranged vertically and horizontally. The patterns of the detection light reflection unit 35 and the detection light absorption unit 36 are provided over the entire irradiation region of the screen 12. The projected light, which is visible light, is reflected by the entire irradiation area where the detection light reflection unit 35 and the detection light absorption unit 36 are provided. Thereby, the observer can observe the image displayed on the whole irradiation region. The detection light that is infrared light is reflected by the portion of the irradiation region where the detection light reflecting portion 35 is provided. The camera 32 detects the detection light reflected by the detection light reflection unit 35. In addition, the detection light reflection part 35 and the detection light absorption part 36 shall make the magnitude | size which can recognize a pattern fully by detecting the detection light reflected by the detection light reflection part 35 with the camera 32. FIG.

  FIG. 4 shows a block configuration for controlling the output of the projection light by the projector 11. The control unit 40 includes a CPU (Central Processing Unit) 46 and a memory 47, and functions as a computer. The memory 47 includes a flash ROM (Read Only Memory) or the like. The control unit 40 controls the driving of the projector 11 by operating the CPU 46 according to the control program stored in the memory 47. The image signal conversion unit 41 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 42. The image signal converter 41 converts the image signal based on the control by the controller 40. For example, the image signal conversion unit 41 converts an image signal input as an analog signal into a digital signal.

  The image signal processing unit 42 performs various image quality adjustment processes on the image signal converted by the image signal conversion unit 41. 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 23R, 23G, and 23B, brightness adjustment, contrast adjustment, sharpness adjustment, and the like. The spatial light modulation driving unit 43 drives the color light spatial light modulation devices 23R, 23G, and 23B based on the image signal processed by the image signal processing unit 42. The projection light source drive unit 44 drives the lamp light source 20 based on the control by the control unit 40.

  Furthermore, the control unit 40 controls the driving of the detection light source unit 31 and the abnormality notification LED 34. Further, the control unit 40 calculates the data from the camera 32 to analyze the detection light pattern detected by the camera 32. In the memory 47, a pattern of the detection light reflecting portion 35 provided on the screen 12 is stored in advance. The control unit 40 collates the pattern recognized by the camera 32 by detecting the detection light with the pattern of the detection light reflection unit 35 stored in the memory 47.

  When the detection light reflected by the detection light reflection unit 35 is detected by the camera 32, the control unit 40 detects the detection light reflection unit 35 in which regions with a large amount of detection light and regions with a small amount of detection light are alternately arranged vertically and horizontally. Recognize the same pattern as The projector 11 can recognize that the projection light is normally incident on the screen 12 by comparing the pattern recognized by the detection light with the pattern of the detection light reflecting portion 35 and determining that they match each other. . When the projection light is normally incident on the screen 12, the control unit 40 outputs the projection light by supplying power to the lamp light source 20 as usual. Further, the abnormality notification LED 34 maintains a state in which it is turned off.

  On the other hand, it is assumed that, for example, a mirror configured using a highly reflective member is placed instead of the screen 12. In this case, the camera 32 detects detection light having a light amount distribution corresponding to the configuration of the mirror. For example, the camera 32 detects detection light having a light amount distribution that is substantially uniform as a whole. For this reason, the control unit 40 does not recognize the same pattern as the pattern of the detection light reflecting unit 35. In this case, the control unit 40 determines that the pattern of the detection light and the pattern of the detection light reflection unit 35 do not match.

  As another case, it is assumed that an intruder such as an observer exists between the projector 11 and the screen 12. As shown in FIG. 5, the shadow S of the entering object is formed in the irradiation area of the screen 12. The camera 32 detects the detection light reflected by the region other than the shadow S region in the irradiation region. For this reason, as shown in FIG. 6, the control unit 40 recognizes the same pattern as the pattern of the detection light reflecting unit 35 only in the region other than the shadow S region. As a result of collating the pattern recognized by the detection light with the pattern of the detection light reflection unit 35, the control unit 40 determines that they do not match. Based on the determination that the pattern recognized by the detection light and the pattern of the detection light reflection unit 35 do not match, the projector 11 can recognize that the projection light is not normally incident on the screen 12.

  The projection light source driving unit 44 stops the power supply to the lamp light source 20 based on the control of the control unit 40 based on the determination that the pattern recognized by the detection light and the pattern of the detection light reflecting unit 35 do not match. . The output of the projection light is stopped by stopping the power supply to the lamp light source 20. As described above, the projector 11 controls the output of the projection light according to the result of collating the pattern recognized by the camera 32 by detecting the detection light with the pattern of the detection light reflection unit 35. Further, the abnormality notification LED 34 is turned on under the control of the control unit 40 based on the determination that the pattern recognized by the detection light does not match the pattern of the detection light reflecting unit 35. The abnormality notification LED 34 notifies the occurrence of an abnormality according to the result of collating the pattern recognized by the camera 32 by detecting the detection light with the pattern of the detection light reflecting portion 35. By lighting the abnormality notification LED 34, it is possible to make the user clearly recognize that an abnormality has occurred and that the output of the projection light has been stopped in response to the occurrence of the abnormality.

  The projector 11 authenticates the screen 12 by collating the pattern recognized by the detection light with the pattern of the detection light reflection unit 35. By stopping the output of the projection light when the screen 12 is not authenticated by the projector 11, it is possible to prevent the projection light from traveling in the direction of the observer. As a result, it is possible to prevent the situation where the projection light travels in the direction of the observer and to reduce the occurrence of defects.

  FIG. 7 is a flowchart for explaining a control procedure according to the result of collating the pattern recognized by the detection light with the pattern of the detection light reflecting unit 35. By turning on the power of the projector 11 in step S1, the detection light source unit 31 supplies detection light in step S2. In step S3, the camera 32 detects detection light. Detection of the detection light by the camera 32 is performed in synchronization with the supply of the detection light in step S2. Next, in step S4, the control unit 40 collates the pattern recognized by the detection light detected in step S3 with the pattern of the detection light reflection unit 35.

  When it is determined by the collation in step S4 that the pattern recognized by the detection light matches the pattern of the detection light reflection unit 35, the projector 11 outputs projection light in step S5. The output of the projection light is started by supplying power to the lamp light source 20 by the control unit 40. Further, the projector 11 projects the projection light modulated in accordance with the image signal onto the screen 12 under the control of the color light spatial light modulators 23R, 23G, and 23B.

  When it is determined by the collation in step S4 that the pattern recognized by the detection light does not match the pattern of the detection light reflecting portion 35, in step S11, the abnormality notification LED 34 notifies the occurrence of abnormality by lighting. . The control according to the result of collating the pattern recognized by the detection light and the pattern of the detection light reflecting portion 35 by the abnormality notification by the abnormality notification LED 34 is completed.

  After the output of the projection light modulated according to the image signal is started, in step S6, the detection light source unit 31 supplies the detection light. In step S7, the camera 32 detects detection light. Detection of the detection light by the camera 32 is performed in synchronization with the supply of the detection light in step S6. Next, in step S8, the control unit 40 collates the pattern recognized by detecting the detection light in step S7 with the pattern of the detection light reflecting unit 35. If it is determined in step S8 that the two patterns match, and the projector 11 is not turned off in step S9, the process returns to step S5 and the projection light output is continued. When the power supply of the projector 11 is turned off in step S9, the control according to the result of collating the pattern recognized by the detection light with the pattern of the detection light reflection unit 35 ends.

  The frequency from the detection light supply in step S6 to the collation in step S8 can be set as appropriate while the projector 11 continues to output the projection light. The supply from the detection light in step S6 to the collation in step S8 may be performed at regular intervals, or may be performed constantly. By using infrared light, which is light other than visible light, as detection light, the screen 12 can be authenticated without hindering display using projection light.

  If it is determined by the collation in step S8 that the pattern recognized by the detection light does not match the pattern of the detection light reflection unit 35, the projector 11 stops outputting the projection light in step S10. The output of the projection light is stopped by stopping the power supply to the lamp light source 20 by the control unit 40. Furthermore, in step S11, the abnormality notification LED 34 notifies the occurrence of abnormality by lighting. The control according to the result of collating the pattern recognized by the detection light and the pattern of the detection light reflecting portion 35 by the abnormality notification by the abnormality notification LED 34 is completed.

  The projector 11 is not limited to controlling the output of projection light by controlling the lamp light source 20. For example, the projector 11 may stop the output of the projection light by expressing the minimum gradation in all the pixels under the control of the spatial light modulators 23R, 23G, and 23B for each color light. The projector 11 may be provided with a shielding unit capable of shielding the projection light, and the output of the projection light may be stopped by controlling the shielding unit. Further, the projector 11 is not limited to the one that stops the output of the projection light when it is determined that the pattern of the detection light and the pattern of the detection light reflection unit 35 do not match, and at least controls to attenuate the output of the projection light. Anything is fine.

  The shapes and sizes of the detection light reflection unit 35 and the detection light absorption unit 36 provided on the screen 12 are not limited to those described in this embodiment. The pattern of the detection light reflection part 35 and the detection light absorption part 36 should just be what can authenticate the screen 12 by collation with the pattern recognized by the detection light and the pattern of the detection light reflection part 35. FIG.

  The screen 12 is obtained, for example, by forming a pattern of an infrared light absorbing member on a general reflective screen. A portion of the screen 12 where the infrared light absorbing member is provided functions as the detection light absorbing portion 36. A portion other than the portion provided with the infrared light absorbing member functions as the detection light reflecting portion 35. The screen 12 is not limited to the screen 12 that functions as the detection reflection unit 35 other than the portion where the detection light absorption unit 36 is provided. For example, the screen 12 forms a pattern using a member having a property of reflecting infrared light with high reflectance with respect to visible light, and the portion provided with such a member functions as the detection light reflecting portion 35. Also good.

  The detection light may be light other than visible light, and is not limited to infrared light. As detection light, for example, ultraviolet light may be used. The projector 11 of this 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 11 is not limited to using a spatial light modulation device. The projector 11 may be a scan type projector that displays an image by scanning light from the light source for projection.

  The abnormality notifying unit is not limited to the abnormality notifying LED 34, and other light emitting means for generating light or a display means for displaying an error may be used. The abnormality notification unit may be another means capable of notifying abnormality, for example, a buzzer or a speaker that is a sound generation means for generating sound. The sound generation means notifies the abnormality by generating sound. Further, the abnormality notification unit may have a plurality of these means.

  FIG. 8 illustrates a projection system according to Embodiment 2 of the present invention. The projector 60 applied to the projection system of the present embodiment is characterized in that the detection light from the detection light source unit 61 and the light from the lamp light source 20 are combined. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. The third dichroic mirror 62 is provided in place of the reflection mirror 27 (see FIG. 2) provided in the optical path of the R light in the projector 11 of the first embodiment. The third dichroic mirror 62 is disposed in the optical path between the lamp light source 20 and the R light spatial light modulator 23R.

  The third dichroic mirror 62 reflects R light and transmits infrared light. The third dichroic mirror 62 functions as a light combining unit that combines the light from the lamp light source 20 and the detection light from the detection light source unit 61. The light source unit 61 for detection is provided on the opposite side of the third dichroic mirror 62 from the side on which the R light is incident. The detection light source unit 61 is, for example, a laser light source that supplies infrared light.

  The R light transmitted through the second dichroic mirror 25 is incident on the third dichroic mirror 62 after the optical path is bent by being reflected by the reflection mirror 26. The R light incident on the third dichroic mirror 62 is reflected by the third dichroic mirror 62 and the optical path is bent, and then travels in the direction of the R light spatial light modulator 23R. The detection light source unit 61 supplies detection light which is infrared light. The detection light from the detection light source 61 passes through the third dichroic mirror 62 and then travels toward the R light spatial light modulator 23R. In this way, the third dichroic mirror 62 combines the R light and the detection light.

  The spatial light modulator for R light 23R modulates the R light and the detection light in accordance with the R light image signal. The R light and the detection light modulated by the spatial light modulator for R light 23R are incident on a different surface of the cross dichroic prism 64 from the surface on which the B light is incident and the surface on which the G light is incident. The first dichroic film 65 of the cross dichroic prism 64 reflects B light and transmits R light, G light, and infrared light. The second dichroic film 66 reflects R light and infrared light and transmits G light and B light. The cross dichroic prism 64 combines the R light, the G light, the B light, and the detection light. The projection lens 30 projects R light, G light, B light, and detection light. By projecting the detection light together with the light from the lamp light source 20 by the projection lens 30, the detection light can be supplied to the entire irradiation region of the screen 12.

  Even when the projector 60 of the present embodiment is used, control according to the result of collating the pattern recognized by the detection light with the pattern of the detection light reflection unit 35 can be performed by the same procedure as the flowchart shown in FIG. is there. This embodiment is different from the first embodiment in that the detection light is modulated according to the image signal in the same manner as the R light. At the time of collation in step S4 and step S8, the control unit 40 (see FIG. 4) can control the color light spatial light modulators 23R, 23G, and 23B so that, for example, all pixels have the highest gradation. It is. By inserting a frame in which all the pixels have the same gradation, it becomes possible to supply detection light to the entire irradiation area of the screen 12. It is desirable to synchronize the frame in which all pixels have the highest gradation with the collation in step S8.

  In addition, detection light modulated according to the image signal may be used for collation. The control unit 40 can obtain a pattern in the case where the detection light modulated according to the image signal is reflected by the detection light reflection unit 35 by performing an operation using the image signal as needed. The control unit 40 collates a pattern when the detection light modulated according to the image signal is reflected by the detection light reflection unit 35 with a pattern recognized by the detection light. In this case, the screen 12 can be authenticated. In the case of the present embodiment as well, it is possible to prevent the situation where the projection light travels in the direction of the observer and reduce the occurrence of problems.

  The projector 60 may combine the detection light from the detection light source unit 61 with not only the R light but also the G light or the B light. The projector 60 may combine the detection light at any position on the optical path from the lamp light source 20 to the spatial light modulators 23R, 23G, and 23B for the respective color lights. The third dichroic mirror 62 can appropriately set the transmission characteristics and the reflection characteristics according to the arrangement of each color light in the optical path.

  FIG. 9 illustrates a projection system according to a modification of the present embodiment. A projector 70 applied to the projection system of the present embodiment includes laser light sources 71R, 71G, and 71B for each color light provided in place of the lamp light source 20 described above. Each color light laser light source 71R, 71G, 71B is a projection light source unit for projecting projection light. Each color light source 71R, 71G, 71B includes, for example, a semiconductor laser. In this modification, the projection light source unit for each color light is used, so that the first dichroic mirror 21 and the second dichroic mirror 25 (see FIG. 8) for separating the light from the projection light source unit into each color light are unnecessary. The optical system can be configured simply. Further, by using the laser light sources 71R, 71G, 71B for each color light that are smaller than the lamp light source 20, the optical system can be made smaller.

  The B light laser light source 71B emits B light which is laser light. The B light from the B light laser light source 71B is incident on the B light spatial light modulator 23B. The G light from the G light laser light source 71G enters the G light spatial light modulator 23G. The R light from the R light laser light source 71 </ b> R enters the dichroic mirror 72. The dichroic mirror 72 transmits R light and reflects infrared light. The dichroic mirror 72 functions as a light combining unit that combines the R light from the R light laser light source 71 </ b> R and the detection light from the detection light source unit 61. The light source unit 61 for detection is provided on the opposite side of the dichroic mirror 72 from the side on which the laser light source 71R for R light is provided.

  The R light incident on the dichroic mirror 72 passes through the dichroic mirror 72 and then travels in the direction of the R light spatial light modulator 23R. The detection light from the detection light source unit 61 is reflected by the dichroic mirror 72 and the optical path is bent, and then proceeds in the direction of the R light spatial light modulator 23R. In this way, the dichroic mirror 72 combines the R light and the detection light. In the case of this modification as well, it is possible to prevent the situation in which the projection light travels in the direction of the observer and reduce the occurrence of problems.

  In addition to using a laser light source as the projection light source unit, for example, a solid light source such as an LED may be used. The projectors 60 and 70 according to the present embodiment may use LCOS, DMD, GLV, or the like as the spatial light modulator as in the case of the above-described embodiment. In each of the above embodiments, the projector is not limited to the configuration including the 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 may be a slide projector that uses a slide having image information.

  FIG. 10 illustrates a projection system according to Embodiment 3 of the present invention. The projector 80 applied to the projection system of the present embodiment is a scan type projector that scans light from a projection light source unit by a scanning unit and displays an image in an irradiation area. The same parts as those in the above-described embodiments are denoted by the same reference numerals, and redundant description is omitted.

  The R light laser light source 81R emits R light modulated in accordance with an image signal. The G light laser light source 81G emits G light modulated in accordance with an image signal. The B light laser light source 81B emits B light modulated in accordance with an image signal. Each color light laser light source 81R, 81G, 81B is a projection light source unit for projecting projection light. Each color light laser light source 81R, 81G, 81B includes, for example, a semiconductor laser.

  The first dichroic mirror 82 reflects R light and transmits infrared light. The second dichroic mirror 83 reflects G light and transmits R light and infrared light. The third dichroic mirror 84 reflects B light and transmits R light, G light, and infrared light. The first dichroic mirror 82, the second dichroic mirror 83, and the third dichroic mirror 84 serve as a light combining unit that combines the light from the laser light sources 81R, 81G, and 81B for each color light and the detection light from the detection light source unit 61. Function. The first dichroic mirror 82, the second dichroic mirror 83, and the third dichroic mirror 84 are disposed in the optical path between the color light laser light sources 81R, 81G, 81B and the scanning unit 85.

  The R light from the laser light source 81R for R light enters the first dichroic mirror 82. The light source unit 61 for detection is provided on the opposite side of the first dichroic mirror 82 from the side on which the laser light source 81R for R light is provided. The R light incident on the first dichroic mirror 82 is incident on the second dichroic mirror 83 after the optical path is bent by reflection at the first dichroic mirror 82. The detection light from the detection light source unit 61 passes through the first dichroic mirror 82 and then enters the second dichroic mirror 83. In this way, the first dichroic mirror 82 combines the R light from the R light laser light source 81 </ b> R and the detection light from the detection light source unit 61.

  The G light from the G light laser light source 81 </ b> G enters the second dichroic mirror 83. The G light incident on the second dichroic mirror 83 is incident on the third dichroic mirror 84 after the optical path is bent by reflection at the second dichroic mirror 83. The R light and the detection light incident on the second dichroic mirror 83 from the first dichroic mirror 82 pass through the second dichroic mirror 83 and then enter the third dichroic mirror 84. In this way, the second dichroic mirror 83 combines the G light from the G light laser light source 81G with the R light and the detection light from the first dichroic mirror 82.

  The B light from the B light laser light source 81 </ b> B is incident on the third dichroic mirror 84. The B light incident on the third dichroic mirror 84 travels in the direction of the scanning unit 85 after the optical path is bent by reflection at the third dichroic mirror 84. The R light, G light, and detection light incident on the third dichroic mirror 84 from the second dichroic mirror 83 pass through the third dichroic mirror 84 and then travel toward the scanning unit 85. In this way, the third dichroic mirror 84 combines the B light from the B light laser light source 81B with the R light, G light, and detection light from the second dichroic mirror 83. It should be noted that the configuration until each color light and detection light is incident on the scanning unit 85 may be changed as long as each color light and detection light can be combined.

  The scanning unit 85 reflects R light, G light, B light, and detection light in the direction of the screen 12. The scanning unit 85 scans the light corresponding to the image signals from the color light laser light sources 81R, 81G, and 81B and the detection light from the detection light source unit 61 in the irradiation region of the screen 12. As the scanning unit 85, for example, a micro electro mechanical system (MEMS) mirror can be used. The MEMS mirror is advantageous in that it is very small and suitable for high-speed driving, and is suitable for miniaturization because a drive unit can be formed in a small configuration. The light from the scanning unit 85 passes through the emission unit 86 provided in the housing 33 and then enters the screen 12.

  Each color light laser light source 81R, 81G, 81B emits light modulated in accordance with an image signal, whereas the detection light source unit 61 emits detection light with a constant output. Thereby, an image is displayed by scanning each color light, and detection light with a uniform light quantity is incident on the irradiation region. Detection of detection light by the camera 32 is performed in synchronization with scanning of detection light by the scanning unit 85. By making it possible to detect the detection light reflected by the detection light reflection unit 35 in the entire irradiation region, the screen 12 can be authenticated by collating the pattern recognized by the detection light with the pattern of the detection light reflection unit 35. In the case of the present embodiment as well, it is possible to prevent the situation where the projection light travels in the direction of the observer and reduce the occurrence of problems.

  In each of the above embodiments, the screen is not limited to a reflective screen. The screen may be a transmissive screen that transmits projection light. A projection system having a transmissive screen supplies images projected from a projector to one surface of the screen and observes light emitted from the other surface of the screen to appreciate images. The detection light reflecting portion used in the transmissive screen can be formed of a member that transmits visible light and reflects infrared light. Also in this case, the output of the projection light can be controlled when a mirror is placed instead of the screen or when an observer enters between the projector and the screen.

  As described above, the projection system according to the present invention is suitable for the case where the projection light from the projector is incident on the screen arranged separately from the projector.

1 is a diagram illustrating a schematic configuration of a projection system according to Embodiment 1 of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of a projector. The figure explaining the structure of a screen. The figure which shows the block structure for controlling the output of the projection light by a projector. The figure which shows the state in which the shadow of the approaching object was formed. The figure explaining the pattern recognized by detection light when an approaching object exists. The flowchart explaining the procedure of control. The figure explaining the projection system which concerns on Example 2 of this invention. FIG. 6 is a diagram for explaining a projection system according to a modification of the second embodiment. The figure explaining the projection system which concerns on Example 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Projection system, 11 Projector, 12 Screen, 20 Lamp light source, 21 1st dichroic mirror, 22 Reflection mirror, Spatial light modulation device for 23R R light, Spatial light modulation device for 23G G light, Spatial light modulation device for 23B B light 24 Cross dichroic prism, 25 Second dichroic mirror, 26, 27 Reflective mirror, 28 First dichroic film, 29 Second dichroic film, 30 Projection lens, 31 Light source for detection, 32 Camera, 33 Housing, 34 Abnormality notification LED, 35 detection light reflection unit, 36 detection light absorption unit, 40 control unit, 41 image signal conversion unit, 42 image signal processing unit, 43 spatial light modulation drive unit, 44 projection light source drive unit, 46 CPU, 47 memory , 60 projector, 61 light source for detection, 62 second Dichroic mirror, 64 Cross dichroic prism, 65 1st dichroic film, 66 2nd dichroic film, 70 projector, 71R R light laser light source, 71G G light laser light source, 71B B light laser light source, 72 Dichroic mirror, 80 projector , 81R R laser light source, 81G G light laser light source, 81B B light laser light source, 82 1st dichroic mirror, 83 2nd dichroic mirror, 84 3rd dichroic mirror, 85 scanning unit, 86 emitting unit

Claims (9)

A projector that projects projection light;
A screen on which the projection light projected by the projector is incident;
A detection light source unit for supplying detection light traveling toward the screen;
A light detection unit that detects the detection light supplied from the detection light source unit and reflected by the screen;
The screen is provided with a detection light reflection portion that reflects the detection light supplied from the detection light source portion in a specific pattern,
The projector controls the output of the projection light according to a result of collating a pattern recognized by the light detection unit by detecting the detection light and a pattern of the detection light reflection unit. Projection system.   The projection system according to claim 1, wherein the detection light is light other than visible light.   The projection system according to claim 1, wherein the detection light source unit is arranged at a position facing the screen in the projector. The projector is
A projection light source unit for projecting the projection light;
The projection system according to claim 1, further comprising: a light combining unit configured to combine light from the projection light source unit and the detection light from the detection light source unit. The projector has a spatial light modulator that modulates light from the light source for projection according to an image signal,
The projection system according to claim 4, wherein the light combining unit is disposed in an optical path between the projection light source unit and the spatial light modulation device. The projector includes a scanning unit that scans light according to an image signal from the projection light source unit,
The projection system according to claim 4, wherein the light combining unit is disposed in an optical path between the projection light source unit and the scanning unit.   The said detection light reflection part is provided in the specific pattern in the substantially whole irradiation area | region which makes the said projection light enter among the said screens, The 1st Claim 6 characterized by the above-mentioned. Projection system. The screen has a detection light absorbing portion that absorbs the detection light,
The said detection light absorption part was provided in parts other than the part in which the said detection light reflection part was provided among the irradiation areas which make the said projection light enter, The Claim 1 characterized by the above-mentioned. The projection system described.   The projector includes an abnormality notification unit that notifies the occurrence of an abnormality according to a result of collating a pattern recognized by the light detection unit by detecting the detection light and a pattern of the detection light reflection unit. The projection system according to any one of claims 1 to 8, wherein:

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