JP2006030369A - projector - Google Patents

Abstract

An object of the present invention is to provide a projector capable of simultaneously preventing an intruder between a projector and a screen from feeling uncomfortable projection light and continuing to view an image.
A spatial light modulator 110 includes a light source unit that supplies illumination light and a plurality of pixel units 404, and modulates light from the light source unit according to an image signal, and light from the spatial light modulator 110 The spatial light modulator 110 includes a projection lens that projects onto a predetermined surface, and the spatial light modulation device 110 detects a light Lr projected from the projection lens and reflected by a shield between the projection lens and the predetermined surface. The light detection unit 406 is provided corresponding to the pixel unit 404, and the spatial light modulator 110 detects the light reflected by the shielding object by the light detection unit 406 according to the position of the shielding object. Thus, the supply of the modulated light Lp from the pixel unit 404 corresponding to the position of the shield is stopped.
[Selection] Figure 4

Description

  The present invention relates to a projector, in particular, a technology of a front type projector.

  A so-called front type projector that observes light projected on a screen or the like from the projector side advances projection light to a space between the projector and, for example, the screen. Since projectors are being used for various purposes such as presentations and home appreciation, it is considered that people may enter between the projector and the screen in various situations. When a person enters between the projector and the screen, for example, the projection light may enter the person's eyes and feel uncomfortable. The projector needs to prevent an intruder from feeling uncomfortable with the projected light. For this purpose, it is conceivable that the supply of projection light is stopped at the same time as a person enters between the projector and the screen. Although stopping the supply of projection light is considered effective in view of preventing an intruder from feeling uncomfortable, it is an obstacle to the viewer for viewing. Also, for example, if the projection light is stopped every time a speaker or passerby enters the presentation, not only will the smooth presentation be interrupted, but stress may be put on the speaker and passers-by for stopping the display of images. May give.

  Therefore, if it is possible to stop supplying the projection light to only the part of the intruder and continue to supply the projection light to other parts, it is possible to prevent the intruder from feeling the projection light unpleasantly and to view the image. It is thought that it can be realized at the same time. In order to control the projection light for the portion that blocks the projection light, it is conceivable to detect the light reflected by the shielding object and stop the supply of the projection light to that position. As a technique for detecting light in a projector or an image display device, for example, there are those proposed in Patent Documents 1 to 3.

JP-A-6-125479 JP-A-6-186585 JP-A-6-138842

  However, the configurations disclosed in Patent Documents 1 to 3 are not for detecting the light reflected by the projection light shield and stopping the supply of the projection light to that position. For this reason, even if these configurations are used as they are, it is difficult to simultaneously prevent the intruder between the projector and the screen from feeling the projection light unpleasantly and continue to view the image. The present invention has been made in view of the above, and provides a projector capable of simultaneously preventing an intruder between a projector and a screen from feeling uncomfortable projection light and continuing to view an image. The purpose is to do.

  In order to solve the above-described problems and achieve the object, according to the present invention, a light source unit that supplies illumination light and a plurality of pixel units, and a space that modulates light from the light source unit according to an image signal. A light modulation device and a projection lens that projects light from the spatial light modulation device onto a predetermined surface. The spatial light modulation device is projected from the projection lens, and is a shield between the projection lens and the predetermined surface. It has a light detection unit for detecting the reflected light, the light detection unit is provided corresponding to the pixel unit, and the spatial light modulator is configured such that the light detection unit corresponding to the position of the shielding object is reflected by the shielding object. By detecting the detected light, it is possible to provide a projector characterized in that the supply of modulated light from the pixel portion corresponding to the position of the shield is stopped.

  When the spatial light modulator and the screen, for example, are in an imaging relationship, the light reflected by the shielding object near the screen returns to the peripheral part of the pixel unit corresponding to the position of the shielding object. In the projector of the present invention, for example, a light detection unit is provided in the periphery of the pixel unit. When the light detection unit detects the light reflected by the shielding object, the spatial light modulation device stops supplying modulated light from the pixel unit corresponding to the position of the shielding object. The projector of the present invention thus stops the supply of projection light to the shielding object. For example, even when a person enters between the projector and the screen, it is possible to prevent the intruder from feeling uncomfortable by interrupting the supply of projection light to the intruder. In addition, the projection light supply is continued for positions other than the position of the shielding object. For example, it is possible to continue projecting an image at a position other than the position of the intruder and to continue viewing the image.

  Thus, by providing the light detection unit corresponding to the pixel unit, it is possible to stop the supply of projection light according to the position of the shielding object. The light reflected by the shielding object returns to the spatial light modulation device as light that is wider than that emitted from the pixel portion. The light detection unit can set the position and size according to the position where the shielding object is expected to enter. By providing the light detection portion in this manner, even if the light returning to the spatial light modulation device returns with a certain extent, the pixel portion can be accurately turned off according to the position of the shielding object. Accordingly, it is possible to obtain a projector that can simultaneously realize that an intruder between the projector and the screen or the like can feel the projection light unpleasant and continue to view the image.

  According to a preferred aspect of the present invention, the spatial light modulation device has a light shielding portion provided between a plurality of pixel portions, and the light detection portion is provided corresponding to the light shielding portion. desirable. For example, a liquid crystal display device, which is a spatial light modulation device, is provided with a light shielding portion in order to block illumination light from entering a TFT element or wiring. By providing the light detection unit corresponding to the light blocking unit, the light detection unit can be prevented from blocking light from the pixel unit, and the light detection unit can be provided corresponding to the pixel unit. Further, by configuring the light detection unit corresponding to the light blocking unit, the light detection unit can be formed relatively easily. Thereby, it can prevent that a photon detection part becomes the obstruction of modulation | alteration light, and can form a photon detection part easily.

  Moreover, according to a preferable aspect of the present invention, it is desirable to further include a condensing lens that condenses the light that is reflected by the shield and travels in the direction of the light detection unit on the light detection unit. The position of the condenser lens can be set in accordance with the position where the shielding object is expected to enter. By providing the condensing lens, the light reflected by the shielding object can be surely advanced to the light detection unit at a position corresponding to the position of the shielding object. As a result, a projector capable of accurately stopping the supply of projection light according to the position of the shielding object can be obtained.

  Moreover, as a preferable aspect of the present invention, it is desirable that the light detection unit is an optical switch element, and the optical switch element is controlled to be turned on / off by light reflected by a shield. For each pixel unit, an optical switch element that is a light detection unit is provided separately from a switch element for driving the pixel unit. The optical switch element turns off the pixel portion by detecting light reflected by the shield. By using an optical switch element as the light detection unit, the pixel unit can be directly turned off in response to light detection without using a complicated controller. As a result, the spatial light modulation device can have a simple configuration, and the pixel portion can be reliably turned off in response to detection of light. Further, the optical switch element may also be used as a switch element that drives the pixel portion. Thereby, the spatial light modulation device can be further simplified.

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

  FIG. 1 shows a schematic configuration of a projector 100 according to Embodiment 1 of the present invention. The projector 100 according to this embodiment is a so-called single-plate projector having a single spatial light modulator 110. The light source device for R light 101R, the light source device for G light 101G, and the light source device for B light 101B have light emitting diode elements (hereinafter referred to as “LEDs” as appropriate) that are solid state light emitting elements. Each color light source device 101R, 101G, and 101B is a light source unit that supplies R light, G light, and B light, which are illumination lights, respectively.

  The R light from the R light source device 101R passes through the lens LN and enters the cross dichroic prism 112. The G light from the G light source device 101G passes through the lens LN and enters the cross dichroic prism 112. The B light from the B light source device 101R passes through the lens LN and enters the cross dichroic prism 112. The projector 100 forms an image of each color light source device 101R, 101G, and 101B at the position of the entrance pupil of the projection lens 130, and irradiates the spatial light modulator 110 with Koehler illumination.

  The cross dichroic prism 112 that is a color synthesis optical system includes two dichroic films 112a and 112b. The dichroic films 112a and 112b are arranged orthogonal to the X shape. The dichroic film 112a reflects R light and transmits G light. The dichroic film 112b reflects B light and transmits G light. In this way, the cross dichroic prism 112 combines the R light, the G light, and the B light.

  The cross dichroic prism 112 performs color synthesis and diffuses each color light to make the light quantity distribution of each color light substantially uniform. The light synthesized by the cross dichroic prism 112 enters a rod integrator 115 that is a light guide optical system. Each color light emitted from the cross dichroic prism 112 is also made uniform in the rod integrator 115 so that the light quantity distribution is substantially uniform. The rod integrator 115 is made of a transparent glass member having a substantially rectangular cross section. The light incident on the rod integrator 115 travels inside the rod integrator 115 while repeating total reflection at the interface between the glass member and air.

  The rod integrator 115 is not limited to one made of a glass member, but may have a hollow structure having an inner surface made of a reflective surface. In the case of a rod integrator having an inner surface as a reflecting surface, light incident on the rod integrator travels inside the rod integrator while being repeatedly reflected on the reflecting surface. Further, the rod integrator may be configured to combine a glass member and a reflecting surface. Each color light whose light quantity distribution is made substantially uniform by the cross dichroic prism 112 and the rod integrator 115 enters the spatial light modulator 110. The spatial light modulator 110 is a transmissive liquid crystal display device that includes a plurality of pixel units and modulates each color light according to an image signal. The projection lens 130 projects the light from the spatial light modulator 110 onto a screen 140 that is a predetermined surface that has an imaging relationship with the spatial light modulator 110.

  The projector 100 is configured to modulate using a single spatial light modulator 110. For this reason, it is desirable that the light source devices 101R, 101G, and 101B for each color light are converted into polarized light having the same vibration direction and supplied. For example, when converting each color light from each color light source device 101R, 101G, 101B into p-polarized light, the spatial light modulator 110 modulates the p-polarized light according to the image signal and converts it into s-polarized light. . In addition, the light source devices 101R, 101G, and 101B for each color light are sequentially turned on so as to be synchronized with the drive of the spatial light modulation device 110 corresponding to the image signal for each color. Note that the light guide optical system is not limited to the rod integrator 115, and for example, a fly-eye lens may be used.

  FIG. 2 shows a state in which an image is displayed on the screen 140 by the projection light from the projector 100. The projector 100 according to the present invention is characterized in that the supply of projection light to the position of the intruder S is stopped when a shielding object enters the space between the projector 100 and the screen 140. Assume that the intruder S shown in FIG. 2 is a shield that enters between the projection lens 130 (see FIG. 1) and the screen 140 that is a predetermined surface.

  FIG. 3 shows a cross-sectional configuration of the main part of the spatial light modulator 110. Each color light synthesized by the cross dichroic prism 112 enters from the incident side dust-proof transparent plate 301 of the spatial light modulator 110 and exits from the emission side dust-proof transparent plate 306. A counter substrate 302 having a transparent electrode or the like is formed inside the incident side dust-proof transparent plate 301. A TFT substrate 305 having TFTs (thin film transistors) and transparent electrodes is formed inside the emission-side dust-proof transparent plate 306. Then, the incident side dustproof transparent plate 301 and the emission side dustproof transparent plate 306 are bonded together with the counter substrate 302 and the TFT substrate 305 facing each other. A liquid crystal layer 304 for image display is sealed between the counter substrate 302 and the TFT substrate 305. Further, a black matrix forming layer 303 is provided on the incident light side of the liquid crystal layer 304 for shielding light. The black matrix forming layer 303 has an opening 311 and a light shielding part 312.

  FIG. 4 illustrates the structure of the pixel portion 404 and the peripheral portion of the pixel portion 404. The light shielding portion 312 is provided at a position corresponding to the TFT element 405 provided on the TFT substrate 305. The TFT element 405 is provided for each pixel portion 404 connected to the pixel electrode 407. The TFT element 405 is a switch element that drives the pixel portion 404 in accordance with an image signal. The TFT element 405 may cause photoelectric conversion when irradiated with illumination light. When the TFT element 405 operates according to the illumination light, it becomes difficult to drive the spatial light modulator 110 according to the image signal. The light shielding unit 312 is provided to block illumination light to the TFT element 405.

  The illumination light from each color light source device 101R, 101G, 101B is transmitted through the opening 311 of the black matrix forming layer 303 and then enters the pixel portion 404 provided in the liquid crystal layer 304. The pixel portion 404 is a cell portion in which liquid crystal molecules are sealed corresponding to the pixels in the liquid crystal layer 304. The light Lp emitted from the pixel unit 404 is projected from the spatial light modulator 110 as modulated light and then projected onto the screen 140. The pixels of the projected image are formed by light emitted from the single pixel unit 404. The amount of light transmitted through the pixel portion 404 varies depending on the arrangement of liquid crystal molecules according to the applied voltage for each pixel portion 404. The spatial light modulator 110 drives the pixel unit 404 by changing the arrangement of liquid crystal molecules according to the applied voltage.

  In order to form projection light by light emitted from the pixel portion 404, the plurality of pixel portions 404 and the openings 311 are arranged in a matrix corresponding to the pixels. The light shielding unit 312 is provided between the plurality of pixel units 404. An optical switch element 406 is provided on the TFT element 405. The optical switch element 406 is a light detection unit that detects the light Lr projected from the projection lens 130 (see FIG. 1) and reflected by the intruder S (see FIG. 2) that is a shield. The optical switch element 406 is controlled to be turned on / off by the light Lr reflected by the intruder S. As the optical switch element 406, for example, a photodiode capable of photoelectric conversion can be used.

  The optical switch element 406 is provided corresponding to the pixel portion 404 as with the TFT element 405. The optical switch element 406 is provided at a position corresponding to the light shielding part 312 on the emission side when viewed from the light shielding part 312. The optical switch element 406 is not limited to being embedded in the emission-side dustproof transparent plate 306, and may be provided separately from the emission-side dustproof transparent plate 306.

  FIG. 5 shows the behavior of the projection light Lp when the intruder S does not enter between the projection lens 130 and the screen 140. FIG. 6 shows the behavior of the reflected light Lr when the intruder S enters between the projection lens 130 and the screen 140. 5 and 6 illustrate the behavior of light from one pixel unit 404 of the projector 100 in order to explain the basis of the present invention. An image P1 of the opening 311 shown in FIG. 5 is formed on the screen 140 by the projection lens 130 and displayed as an image P2. As described above, the spatial light modulator 110 and the screen 140 are in an imaging relationship. Note that the optical switch element 406 may be provided in parallel with the TFT element 405 corresponding to each pixel portion 404.

  When the intruder S enters between the projection lens 130 and the screen 140, the light Lr reflected by the intruder S passes through the projection lens 130 and returns to the original pixel unit 404. While the spatial light modulation device 110 and the screen 140 are in an imaging relationship, the intruder S and the spatial light modulation device 110 are somewhat deviated from the imaging relationship. For this reason, the light Lr returns to the spatial light modulator 110 with a certain degree of spread as compared to when the light is emitted from the pixel unit 404. FIG. 6 shows a state where the light Lr is incident on the optical switch element 406 provided corresponding to a certain pixel portion 404. In this way, the light Lr is detected by the optical switch element 406 corresponding to the position of the intruder S.

  FIG. 7 shows a circuit configuration for driving the spatial light modulator 110. The pixel array unit 701 includes a plurality of pixel circuits 710 arranged in a matrix. The pixel circuit 710 drives the pixel unit 404. Each pixel circuit 710 is connected to a data line Xm (m = 1 to M) and an address line Yn (n = 1 to N). The data line Xm is a wiring extending along the column direction in the array of the pixel circuits 710 and is also referred to as a “source line”. The address line Yn is a wiring extending along the row direction in the array of the pixel circuits 710 and is also referred to as a “gate line”.

  The address line drive circuit 702 supplies an address line selection signal based on an address line drive signal from a controller (not shown). The address line driver circuit 702 selectively drives one address line Yn by an address line selection signal to select a group of pixel circuits 710 for one row (set to high level). The data line driving circuit 703 supplies a data signal to each pixel circuit 710 via each data line X1 to XM based on a data line driving signal from a controller (not shown). The applied voltage of the pixel portion 404 is controlled according to the data signal.

  FIG. 8 shows a detailed configuration of the pixel circuit 710. A pixel circuit 710 illustrated in FIG. 8 is a configuration example in a normally black mode liquid crystal display device which transmits light when a voltage is applied to the pixel portion 404. The gate electrode of the TFT element 405 is connected to the address line Yn. The source electrode of the TFT element 405 is connected to the data line Xm. The drain electrode of the TFT element 405 is connected to the photodiode 803, the pixel portion 404, and the storage capacitor 802. The photodiodes 803 and 804 and the resistance portion 806 are connected in series. The photodiodes 803 and 804 are connected in series so that the sign is reversed. The photodiode 803 to the resistor portion 806, the pixel portion 404, and the storage capacitor 802 are connected in parallel between the TFT element 405 and the counter electrode 803. Note that the position of the resistance portion 806 is not limited to that illustrated. Further, the pixel circuit 710 may have a structure in which the resistor portion 806 is not provided.

  When the address line Yn is selected by the address line selection signal, the TFT element 405 on the address line Yn is turned on. When the TFT element 405 is turned on, electric charge is supplied to the storage capacitor 802 in accordance with a predetermined voltage value set based on the data line drive signal at that time. The pixel unit 404 is turned on (transmits light) at a gradation corresponding to a predetermined voltage value. The applied voltage of the pixel portion 404 is maintained by the charge held in the storage capacitor 802 until the next writing is performed. Thus, when the light Lr reflected by the intruder S is not incident, the pixel unit 404 is driven according to the current from the TFT element 405.

  On the other hand, when the light Lr is incident on the photodiodes 803 and 804, the equivalent resistance values of the photodiodes 803 and 804 are reduced, and the charge of the storage capacitor 802 flows out from the counter electrode 808. The voltage applied to the pixel portion 404 becomes substantially zero when the charge of the storage capacitor 802 flows out. The pixel portion 404 is turned off when the applied voltage becomes substantially zero.

  FIG. 9 illustrates a configuration example of the pixel circuit 910 in a normally white mode liquid crystal display device that transmits light when the voltage applied to the pixel portion 404 is substantially zero. The resistor portion 806 and the photodiodes 803 and 804 are connected in series. Further, both ends of the resistor portion 806 to the photodiode 803 are connected to a positive power source or a high potential bias line and a high potential side terminal of the pixel portion 404. Note that the position of the resistance portion 806 is not limited to that illustrated. The pixel circuit 910 may have a structure in which the resistor portion 806 is not provided.

  When the light Lr is incident on the photodiodes 803 and 804, the equivalent resistance values of the photodiodes 803 and 804 decrease, and the charge from the positive power source flows into the storage capacitor 802. When the charge from the storage capacitor 802 is supplied, a voltage is applied to the pixel portion 404. The pixel portion 404 is turned off when a voltage is applied.

  In general, in order to reduce deterioration of the liquid crystal in the pixel portion 404, the pixel portion 404 is driven by a common potential that is periodically inverted. In the pixel circuits 710 and 910, the light detection unit is configured by two photodiodes 803 and 804 having positive and negative in order to cope with both positive and negative applied voltages. In the case where the pixel portion 404 is driven without inverting the common potential, any one of the photodiodes 803 and 804 may be provided as the light detection portion.

  When the projector 100 is used for the purpose of presentation, there may be a scene where a speaker or the like enters the position of the screen 140 on the projector 100 side, or a scene where the participant has to cross between the projector 100 and the screen 140. . Further, even when the projector 100 is used for home use, similarly, a situation where an observer or the like blocks the projection light is sufficiently conceivable. For such a situation, for example, it is conceivable to set the intensity of the projection light so that the intruder does not feel uncomfortable. In this case, it is possible to prevent an intruder from feeling uncomfortable with the projected light, but a bright projected image cannot be obtained.

  In addition, a configuration in which all the light emitted from the projector 100 is shut down when the intruder S enters is conceivable. If a configuration is adopted in which all the emitted light is shut down, it is considered that light can be supplied with an intensity capable of obtaining a bright projection image. In this case, the projection light is stopped every time the intruder S enters, so that not only the smooth presentation is disturbed, but also the speaker or passerby may be stressed by stopping the display of the image. obtain. Further, in the configuration in which the light source unit is turned off when the intruder S enters, it may be considered that it takes a long time to restart the light source unit. If it takes a long time to restart the light source unit, it will further hinder image appreciation and presentation.

  The projector 100 of the present invention stops the supply of modulated light from the pixel unit 404 corresponding to the position of the intruder S. The projector 100 can block the supply of the projection light Lp to the intruder S between the projector 100 and the screen 140 and prevent the intruder S from feeling uncomfortable with the projection light. Further, for positions other than the position of the intruder S, the supply of the projection light Lp is continued as it is. For positions other than the position of the intruder S, it is possible to continue projecting the image and continue to view the image.

  Thus, by providing the optical switch element 406 corresponding to the pixel portion 404, the supply of the projection light Lp can be stopped according to the position of the shielding object. The light Lr reflected by the shielding object returns to the spatial light modulation device as light that is wider than when emitted from the pixel unit 404. The position and size of the optical switch element 406 can be set according to the position where the shielding object is expected to enter. By providing the optical switch element 406 in this way, even if the light Lr returns with a certain degree of spread, the pixel portion 404 can be accurately turned off according to the position of the shielding object. Thereby, it is possible to simultaneously prevent the intruder S between the projector 100 and the screen 140 and the like from feeling uncomfortable with the projection light and continue to view the image.

  Further, by providing the optical switch element 406 corresponding to the light shielding portion 312, the optical switch element 406 can be prevented from blocking light from the pixel portion 404, and the optical switch element 406 is provided corresponding to the pixel portion 404. be able to. The optical switch element 406 can be formed, for example, by changing a mask pattern when forming the TFT element 405. Thus, the optical switch element 406 can be formed relatively easily by making the optical switch element 406 correspond to the light shielding portion 312. Further, since it is possible to switch the modulated light with a simple configuration, it is not necessary to provide a complicated configuration for shutting down the projection light. As a result, the optical switch element 406 is prevented from interfering with the modulated light, and the optical switch element 406 can be easily formed.

  The position and size of the optical switch element 406 can be set so that the position where a blocking object such as the intruder S enters can be predicted and the pixel unit 404 can be accurately turned off according to the position of the blocking object. For example, if the optical switch element 406 is provided at a position that is in an imaging relationship with the position where the entry of the shielding object is expected, the projection light can be accurately blocked at the position of the shielding object. Such a setting of the optical switch element 406 can be changed as appropriate according to the application and usage status of the projector 100.

  When the light Lr spreads back to the spatial light modulator 110 more broadly than shown in FIG. 6, the light Lr is incident on each optical switch element 406 corresponding to the original pixel unit 404 and the surrounding pixel unit 404. . In this case, the supply of the projection light is stopped for the position of the intruder S and the surrounding positions. Also in this case, the discomfort of the intruder S can be sufficiently prevented.

  The optical switch element 406 is not limited to be provided corresponding to all the pixel units 404 of the spatial light modulator 110, and one optical switch element 406 may be configured to correspond to a plurality of pixel units 404. For example, when light from a shield is detected by the optical switch element 406, the supply of modulated light from the pixel unit 404 provided around the optical switch element 406 is stopped. Thereby, supply of modulated light can be stopped according to the position of the shield. When one optical switch element 406 corresponds to a plurality of pixel portions 404, it is desirable that the optical switch elements 406 are provided at substantially equal intervals in the spatial light modulator 110. Further, as the number of the optical switch elements 406 is increased, the supply of the modulated light can be stopped accurately corresponding to the position of the shielding portion.

  The optical switch element 406 is not limited to the case where it is provided at the position on the screen 140 side of the light shielding portion 312 and the TFT element 405 shown in FIG. For example, the optical switch element 406 may be arranged in parallel with the TFT element 405. The optical switch element 406 may be formed integrally with the TFT element 405. Further, the optical switch element 406 may not be provided separately from the TFT element 405, and the TFT element 405 may also function as the optical switch element 406.

  FIG. 10 illustrates the configuration of a spatial light modulation device 1110 according to the second embodiment of the present invention. The spatial light modulation device 1110 of this embodiment can be applied to the projector 100 described above. The same parts as those of the projector 100 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The spatial light modulator 1110 of this embodiment includes a condenser lens 1001. The condenser lens 1001 is provided on the screen 140 side of the optical switch element 406.

  FIG. 11 shows the behavior of the reflected light Lr when the intruder S enters between the projection lens 130 and the screen 140. The light Lr reflected by the intruder S passes through the projection lens 130 and then enters the condenser lens 1001. The light Lr incident on the condenser lens 1001 is condensed on the optical switch element 406 corresponding to the original pixel unit 404. The condensing lens 1001 condenses the light Lr reflected by the intruder S and traveling in the direction of the optical switch element 406 on the optical switch element 406. When the condenser lens 1001 is provided, the light Lr returning to the spatial light modulator 110 with a certain extent can be guided to the optical switch element 406 corresponding to the original pixel unit 404.

  The position of the condenser lens 1001 can be set in accordance with the position where the shielding object is expected to enter. By setting the position of the condensing lens 1001 in this way, even if the light Lr returns with a certain degree of spread, the pixel portion 404 can be accurately turned off according to the position of the shielding object. Thereby, there is an effect that the supply of the projection light can be stopped accurately according to the position of the shielding object. In addition, the condensing lens 1001 should just be in the screen 140 side from the optical switch element 406, and is not restricted to the structure provided on the emission side dust-proof transparent plate 306. The condenser lens 1001 may be provided directly on the optical switch element 406, for example.

  FIG. 12 illustrates a configuration of a spatial light modulation device 1210 according to a modification of the present embodiment. The spatial light modulator 1210 includes a plurality of microlens elements 1201 and 1202 on the illumination light incident side and the modulated light Lp emission side, respectively. The microlens element 1201 is provided to guide illumination light to the opening 311. The microlens element 1202 converts the light focused by the microlens element 1201 into substantially parallel light. By providing the microlens element 1202, the spread of the modulated light Lp until it enters the projection lens 130 can be reduced. Note that the microlens element 1202 is not necessarily required, and may be omitted if the spread of the modulated light Lp is allowed.

  The spatial light modulation device 1210 of this modification is characterized in that the microlens element 1202 is provided at a position other than the position where the reflected light Lr is incident on the optical switch element 406. For example, if the reflected light Lr incident on the optical switch element 406 is incident on the microlens element 1202, the reflected light Lr may travel to a position other than the optical switch element 406. Therefore, by providing the microlens element 1202 at a position other than the position where the reflected light Lr enters the optical switch element 406, the reflected light Lr can be reliably incident on the optical switch element 406.

  Further, a condensing lens 1301 may be provided at a position where the reflected light Lr is incident on the optical switch element 406 as in the spatial light modulator 1310 shown in FIG. By providing the condenser lens 1301, the reflected light Lr can be accurately guided to the optical switch element 406 corresponding to the original pixel portion 404.

  The projector 100 is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulator 110, but may be a reflective liquid crystal display device or a tilt mirror device. An example of a tilt mirror device is a DMD from Texas Instruments. The tilt mirror device has a movable mirror element as a pixel portion. When the light detection unit detects the light reflected by the shielding object, the movable mirror element is controlled so that the modulated light is not projected onto the shielding object. In this way, the projector using the tilt mirror device can also stop supplying the projection light to the shielding object in the same manner as the projector 100 described above. Further, the projector 100 is not limited to the case where the LED is used as the light source unit, but may be another solid light emitting element, a lamp such as an ultrahigh pressure mercury lamp, or a laser light source. Further, the projector 100 is not limited to a so-called single-plate projector having a single spatial light modulator 110, but also a so-called three-plate projector having a plurality of spatial light modulators can be shielded in the same manner as the projector 100. The supply of projection light to an object can be stopped.

  As described above, the projector according to the present invention is useful when displaying a presentation or a moving image.

1 is a schematic configuration diagram of a projector according to a first embodiment of the invention. Explanatory drawing of the state which displays an image on a screen with a projector. The principal part cross-section block diagram of a spatial light modulation device. FIG. 3 is a configuration diagram of a pixel portion and a peripheral portion of the pixel portion. Explanatory drawing of behavior of projection light. Explanatory drawing of behavior of projection light. The circuit block diagram for driving a spatial light modulation device. FIG. 9 illustrates a configuration example of a pixel circuit. FIG. 9 illustrates a configuration example of a pixel circuit. Explanatory drawing of the spatial light modulation apparatus which concerns on Example 2 of this invention. Explanatory drawing of behavior of projection light. FIG. 10 is an explanatory diagram of a spatial light modulation device according to a modification of the second embodiment. FIG. 10 is an explanatory diagram of a spatial light modulation device according to a modification of the second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Projector, 101R R light source device, 101G G light source device, 101B B light source device, 110 Spatial light modulator, 112 Cross dichroic prism, 112a, 112b Dichroic film, 115 Rod integrator, 130 Projection lens, 140 Screen, LN lens, S intruder, 301 incident side dustproof transparent plate, 302 counter substrate, 303 black matrix forming layer, 304 liquid crystal layer, 305 TFT substrate, 306 exit side dustproof transparent plate, 311 opening, 312 light shielding portion, 404 Pixel part, 405 TFT element, 406 optical switch element, 407 pixel electrode, 701 pixel array part, 702 address line driving circuit, 703 data line driving circuit, 710 pixel circuit, Xm data line, Yn address line 802 Retention capacitor, 803, 804 photodiode, 806 resistor, 808 counter electrode, 910 pixel circuit, 1001 condenser lens, 1010 spatial light modulator, 1201, 1202 microlens element, 1210 spatial light modulator, 1301 Optical lens, 1310 spatial light modulator

Claims (4)

A light source unit for supplying illumination light;
A spatial light modulator that includes a plurality of pixel units and modulates light from the light source unit according to an image signal;
A projection lens that projects light from the spatial light modulation device onto a predetermined surface in an imaging relationship with the spatial light modulation device;
The spatial light modulator has a light detection unit that detects light projected from the projection lens and reflected by a shield between the projection lens and the predetermined surface,
The light detection unit is provided corresponding to the pixel unit,
In the spatial light modulation device, the light detection unit corresponding to the position of the shielding object detects light reflected by the shielding object, so that the modulated light from the pixel unit corresponding to the position of the shielding object is detected. A projector characterized by stopping supply. The spatial light modulation device has a light shielding portion provided between the plurality of pixel portions,
The projector according to claim 1, wherein the light detection unit is provided at a position corresponding to the light shielding unit.   The projector according to claim 1, further comprising a condensing lens that condenses the light reflected by the shield and traveling toward the light detection unit on the light detection unit. The light detection unit is an optical switch element,
The projector according to claim 1, wherein the optical switch element is controlled to be turned on / off by light reflected by the shield.

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