JP2002006397A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent light being projected on a screen through a projection optical system, etc., from being directly made incident on a human eye accidentally and to ensure security when a lighting source with high power is used or a laser beam source is used. SOLUTION: When an object near a projection lens 8 is detected by a photo- coupler 20, a spatial optical modulation element 6 is controlled so as to set the full screen as black display by a system controller 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device for displaying an image by projecting illumination light or laser light onto a screen.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 14, an illumination light source 101 such as a halogen lamp is provided, and illumination light emitted from the illumination light source is converted into a display image by a spatial light modulator 102 such as a liquid crystal display device. There has been proposed an image display device configured to modulate the illumination light in response to the modulated illumination light and project the enlarged illumination light onto a screen 104 via a projection optical system (projection lens) 103. Among such image display devices, a device configured to observe reflected light of the illumination light projected on the screen 104 by the screen 104 is known as a front projection type image display device.

As the spatial light modulator 102, a digital micromirror, a movable grating or the like can be used in addition to a liquid crystal display device. Liquid crystal display devices include an optical rotation (polarization guided) mode type, a birefringence mode type, a light scattering mode type, and a light absorption mode type. Optical rotation (polarized wave guide) as a commonly used liquid crystal display device
TN liquid crystal using mode-type twisted nematic (TN) operation mode, FLC type using STN liquid crystal using birefringent operation mode-type super twisted nematic (STN) operation mode, and ferroelectric liquid crystal (FLC) operation mode and so on.

As shown in FIG. 15, a cathode ray tube (C
RT), the light emitted from the self-luminous image display element 105 is incident on the projection optical system 103, and the self-luminous image display element 105
There has been proposed a projection-type image display device that enlarges and projects a display image on a screen 104. Among such image display devices, a device configured to observe reflected light of the light projected on the screen 104 by the screen 104 is called a front projection type image display device.

In the above-described front projection type image display device, for example, as compared with a self-luminous type image display device such as a cathode ray tube (CRT) or an image display device of a system in which a liquid crystal display device is directly viewed, A large-screen display such as a diagonal of 40 inches or more can be easily realized.

[0006]

Incidentally, in the above-described image display device, it is desired to further increase the size of the display image and improve the brightness of the display image. The size of the displayed image can be increased by changing the projection magnification in the projection optical system. In this case, the projection is performed by increasing the output of the illumination light source or increasing the aperture ratio of the spatial light modulator. The output of the illumination light projected from the optical system must be increased. This is because the luminance of the display image decreases in inverse proportion to the area of the display image.

In order to improve the luminance of a displayed image, a laser light source may be used as an illumination light source. When a laser light source is used as the illumination light source, light emitted from the exit surface of the projection optical system has very high coherence and is close to parallel light.

On the other hand, by shortening the arc length of the illumination light source,
The size of the front-projection image display device has been reduced by reducing the size of the spatial light modulator and the lens aperture of the projection optical system. The front-projection image display device thus miniaturized is easy to carry, and is therefore expected to be used in any state and anywhere, for example, in a general home.

Therefore, in the front projection type image display device thus miniaturized, the illumination light to be projected on the screen via the projection optical system directly enters the pupil of the observer. That situation is expected to occur. In this case, if a high-output light source, a laser light source, or the like is used, a body organ such as a cornea or a retina may be affected.

Therefore, the present invention has been proposed in view of the above situation, and is a front projection type image display device in which light projected on a screen via a projection optical system or the like is erroneously output to a human. The present invention aims to provide an image display device which is prevented from entering the eyes of a subject, and which does not affect body organs such as the cornea and the retina, even if the illumination light source has a high output or is a laser light source. Things.

[0011]

In order to solve the above-mentioned problems, an image display apparatus according to the present invention comprises an illumination light source and a spatial light modulator for modulating illumination light emitted from the illumination light source in accordance with an input signal. A projection optical system for projecting illumination light modulated by the spatial light modulator onto a screen, projection light output control means for controlling an output of the illumination light projected by the projection optical system, and a projection optical system. And object sensing means for sensing the presence of an object between the screens and outputting a sensing result. The image display device is characterized in that the projection light output control means controls the output of the illumination light projected by the projection optical system according to the output from the object sensing means.

In the image display apparatus according to the present invention, in the above-described image display apparatus, instead of the object sensing means, an image pickup means for picking up an image formed by illumination light projected on a screen and outputting an image signal. And a comparison operation means for comparing an input signal to the spatial light modulation element with an image signal output from the imaging means and outputting a comparison result, wherein the projection light output control means outputs the comparison light from the comparison operation means. Depending on,
This is to control the output of the illumination light projected by the projection optical system.

Further, according to the image display device of the present invention, in each of the above-described image display devices, the illumination light source, the spatial light modulator, the projection optical system, and the projection light output control means are controlled according to the laser light source and the input signal. Light output modulation means for modulating the light output of the laser light, scanning means for scanning the laser light emitted from the laser light source on a screen, and light output control for controlling the light output of the laser light scanned by the scanning means It is an alternative to means.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] An image display device according to the present invention includes an illumination light source 1 as shown in FIG. As the illumination light source 1, for example, a halogen lamp or the like can be used. The illumination light emitted from the illumination light source 1 enters the illumination optical system 2. The illumination optical system 2 corrects the cross-sectional shape of the light beam of the incident illumination light, makes the intensity uniform, controls the divergence angle, and the like. The illumination light passing through the illumination optical system 2 is reflected by the mirror 3 and deflected by 90 °,
And enters the total reflection prism 5. The color wheel 4 time-divides white light emitted from the illumination light source 1 into red (R), green (G), and blue (B) spectral components. By such time division, a color image can be displayed by a so-called “field sequential color method” using a single spatial light modulation element described later.

The illumination light totally reflected by the total reflection surface 5a of the total reflection prism 5 enters a DMD (digital micromirror display) panel 6 which is a spatial light modulator. As shown in FIG. 2, the DMD panel 6 includes a large number (a number of pixels) of square aluminum micromirrors 6a corresponding to one pixel. Each aluminum micro mirror 6
As shown in FIG. 3, a is rotatably supported by columns (posts) 6c by two hinges 6b provided at diagonal portions. Each of the aluminum micromirrors 6a is tilted in any direction by a Coulomb between the electrodes in the lower layer of the aluminum micromirrors 6a to switch the direction of reflecting the incident light as shown in FIG. It has become. The tilt angle is about 15 ° at the maximum from the horizontal state. That is, the DMD panel 6
Illumination light incident on the aluminum micromirror 6a serving as each pixel of the DMD panel 6 receives a "white pixel" (O
N) in the aluminum micromirror 6a, DM
A projection optical system 8 which is reflected on the front side of the D panel 6 and will be described later.
, The light is reflected in the direction opposite to the incident side on the aluminum micromirror 6a which becomes the “black pixel” (OFF).

The illumination light reflected by the aluminum micromirror 6a, which becomes "white pixels" (ON), passes through an optical path length correcting prism 7 as shown in FIGS.
And is imaged on the screen 9. On the other hand, the illuminating light reflected by the aluminum micromirror 6a that becomes “black pixels” (OFF) does not reach the screen 9 without being incident on the projection optical system 8 as shown in FIG.

As described above, in the DMD panel 6,
Since each aluminum micromirror 6a corresponding to each pixel has a binary inclination angle, it is possible to switch between light and dark for each pixel, and pass the reflected light from these aluminum micromirrors 6a to the projection optical system 8. Thus, an image can be displayed on the screen 9.

In this image display device, the DMD panel 6 is controlled by a system controller (control circuit) 12 so as to modulate incident illumination light in accordance with an image signal 10. That is, the image signal 10 which is an analog signal is converted into a digital signal via the A / D converter 11 and is input to the system controller 12. The system front roller 12 controls the DMD panel 6 via the DMD drive control circuit 13 according to the input image signal. Also, the system controller 12
Controls the color wheel 4 via the color wheel drive control circuit 14. That is, the system front roller 12 performs synchronization signal generation, image signal processing, gamma correction, and the like based on the input image signal, and outputs control signals to the DMD drive control circuit 13 and the color wheel drive control circuit 14, respectively. I do. DMD drive control circuit 13
And the color wheel drive control circuit 14 converts the control signal into a DMD drive signal based on the input control signal.
Rearrangement, generation of a color wheel motor control current, and the like are performed and sent to the DMD panel 6 and the color wheel 4, respectively, to realize a color image display by the “field sequential color method”.

This image display device has infrared photocouplers 20 and 21 as object sensing means. As shown in FIG. 6, each of the infrared photocouplers 20 and 21 includes an infrared LED (light emitting diode) 22 as a light emitting element and a phototransistor (or photodiode) 23 as a light receiving element. These infrared photocouplers 20 and 21 are controlled by a system controller 12 also serving as a projection light output control unit.

The infrared LED 22 is controlled by the system controller 12, and emits infrared light at a duty ratio of 1/10 in synchronization with a data switching cycle (about 10 μsec) in the DMD panel 6. The output from the phototransistor 23 is at least the infrared LED 22.
Is monitored by the system controller 12 for a time longer than the light emission time of Here, infrared LE
Phototransistor 23 during period when D22 is not emitting light
Is the DC (direct current bias) component due to external light, and the output of the phototransistor 23 during the period when the infrared LED 22 is emitting light is the object detection component. The object detection component is
The light emitted from the infrared LED 22 is reflected by some object and enters the phototransistor 23. And the system controller 12
If the value obtained by subtracting the DC component from the object detection component is equal to or greater than a certain value, it is determined that some object exists near the illumination light emitting unit (front end) 8a of the projection optical system 8.

When the system controller 12 determines that there is any object near the illumination light emitting section 8a of the projection optical system 8, the system controller 12 issues a command of "all black display" to the DMD.
The data is sent to the drive control circuit 13 so that the next time the data of the DMD panel 6 is rewritten, a state of black display on the entire surface, that is, a state where all the illumination light does not reach the projection optical system 8 is set.

Since the DMD panel 6 used as a spatial light modulator in this embodiment can operate at a very high speed, it can be quickly switched to a black display state by the control of the system controller 12. It is possible.

In this image display device, a plurality of infrared photocouplers 20 and 21 are arranged substantially symmetrically with respect to the optical axis of the projection optical system 8, whereby the infrared photocouplers 20 and 21 are emitted from the projection optical system 8. This prevents the danger of accidentally directing the illumination light directly into the eyes. In this embodiment,
The detection of an object relatively near the illumination light emitting portion 8a of the projection optical system 8 is performed.

The object sensing means adjusts the light receiving range (directivity) of the light receiving element so that at least a part of the illumination light projected by the projection optical system 8 and forming an image on the screen 9 is blocked by the object. It may be detected that the operation has been performed. Further, three or more infrared photocouplers may be provided.

In the above-described embodiment, a surface emitting laser can be used instead of the illumination light source and the spatial light modulator. The surface-emitting laser performs image display by self-emission according to an image signal under the control of the system controller 12.

Further, a ferroelectric liquid crystal panel, a grating live (GLV), or the like can be used as the spatial light modulator.

The object sensing means may be replaced with only a light receiving element for detecting the reflected light of the illumination light projected by the projection optical system 8 from the object, instead of the photocoupler. In this case, the presence of an object can be detected based on whether or not a predetermined percentage or more of the illumination light projected by the projection optical system 8 is received by the light receiving element. That is, in the state where the illumination light is reflected by an object existing closer to the screen than in the state where all of the illumination light projected by the projection optical system 8 reaches the screen, more light is emitted. Is incident on the light receiving element.

The light receiving element in the object sensing means is
It may be an image sensor. The light receiving element serving as the object sensing means may be arranged on the screen side.
In this case, the object detecting means detects the presence of an object near the screen 9. In this case,
By providing the light receiving element outside the image display area on the screen, optical detection of an object existing around the image formed on the screen without being affected by the illumination light projected by the projection optical system 8 It can be performed.

Further, the object sensing means may receive light via an imaging optical system whose optical axis coincides with that of the projection optical system 8. That is, in the projection optical system 8, since the DMD panel 6 and the image display area on the screen 9 are in a conjugate relationship, the periphery of the DMD panel 6 is conjugate with the periphery of the image display area on the screen 9. In a relationship. Therefore, by providing the light receiving element around the DMD panel 6, an object existing around the image display area on the screen 9 can be detected via the projection optical system 8. In this case, the light receiving element may receive light only through a part of the projection optical system 8.

Further, the object sensing means includes a microwave transmitting device and a microwave receiving device, and the microwave receiving device detects the reflected wave of the microwave emitted from the object by the microwave receiving device. Can also be used. Further, as the object sensing means, an ultrasonic sensor, an infrared sensor, or the like may be used.

In the above-described embodiment, when the system controller 12 determines that an object exists between the projection optical system 8 and the screen 9 based on the output from the object sensing means, the system controller 12 determines “all black”. Instead of “display”, the illumination light source 1 may be turned off. The operation of turning off the illumination light source 1 will be described later.

When the system controller 12 determines from the output from the object sensing means that an object exists between the projection optical system 8 and the screen 9, the system controller 12 switches the illumination light source 1 to the projection optical system. The light path blocking element or the shutter disposed in the light path to 8 may be in a state of blocking the illumination light. A ferroelectric liquid crystal panel can be used as the light path blocking element and the shutter. The light path blocking element and the shutter will be described later. As means for attenuating the amount of light radiation from the projection optical system, two or more of the above-described means may be used in combination.

Further, according to the present invention, during operation (during image display)
In addition, it is effective as an operation at the start of operation (at the start of image display). That is, according to the output of the object sensing means at the start of operation, the power of the illumination light source is not turned on, the optical shutter is set in the blocking state, the image display element is displayed entirely black regardless of the input of the image signal, and the like. By performing the control, a safe image display device can be configured.

[Second Embodiment] Next, a description will be given of a configuration in which the amount of illumination light projected from the projection optical system is attenuated by closing the optical shutter. First, a ferroelectric liquid crystal (FL) that can be used as an optical shutter
The configuration and operation principle of C) will be described. As shown in FIGS. 7A and 7B, the ferroelectric liquid crystal 30
A pair of glass substrates 31 and 32 are provided, and a liquid crystal material 33 is sandwiched between the pair of glass substrates 31 and 32. Transparent electrodes 34 and 35 and alignment films 36 and 37 for aligning the direction of molecules of the liquid crystal material 33 are provided on the opposing surfaces of the pair of glass substrates 31 and 32, respectively. Here, the alignment direction by the alignment film 36 provided on one glass substrate 31 and the alignment direction by the alignment film 37 provided on the other glass substrate 32 are directions parallel to each other.

The transparent electrode 3 on one glass substrate 31
The polarizer 38 is provided on the surface opposite to the surface on which the alignment film 4 and the alignment film 36 are provided, and the transparent electrode 35 on the other glass substrate 32 is provided.
The analyzer 3 is provided on the surface opposite to the surface on which the alignment film 37 is provided.
9 are provided.

The polarizer 38 is provided on one glass substrate 31 so that its polarization direction is parallel to the alignment direction of the alignment film 36 provided on the one glass substrate 31. The analyzer 39 is provided on the other glass substrate 32 so that its polarization direction is orthogonal to the alignment direction of the alignment film 37 provided on the other glass substrate 32. That is, the polarizer 38 and the analyzer 39 are arranged so that their polarization directions are orthogonal to each other.

As shown in FIG. 7C, the liquid crystal material 33 sandwiched between the pair of glass substrates 31 and 32 produces a birefringence effect in accordance with the direction of the electric field due to the applied voltage. It takes one of two states, "state 1" in which no birefringence is caused, and "state 2" in which a birefringence effect is generated.

Here, assuming that the liquid crystal material 33 assumes the “state 1” when the electric field is in the direction shown in FIG. 7A, light incident on the ferroelectric liquid crystal 30 is reflected by the polarizer 38. The polarization plane component having the same polarization direction as the incident light transmits through the polarizer 38 and enters the liquid crystal material 33 sandwiched between the pair of glass substrates 31 and 32 via the transparent electrode 34 and the alignment film 36. .

The light incident on the liquid crystal material 33 reaches the analyzer 39 provided on the other glass substrate 32 without being subjected to the birefringence effect of the liquid crystal material 33. Therefore, the incident light is blocked by the analyzer 39 and does not appear as transmitted light.

Assuming that the liquid crystal material 33 assumes the “state 2” when the electric field is in the direction shown in FIG. 7B, the light incident on the ferroelectric liquid crystal 30 is polarized by the polarizer 38. The polarization plane component in the same direction as the incident light 30 is the polarizer 3
8 through a transparent electrode 34 and an alignment film 36 to enter a liquid crystal material 33 sandwiched between a pair of glass substrates 31 and 32.

The incident light that has entered the liquid crystal material 33 is subjected to the birefringence effect of the liquid crystal material 33 and reaches the analyzer 39 provided on the other glass substrate 32 with the polarization direction twisted at a right angle. . Therefore, the incident light is
9 and is emitted from the ferroelectric liquid crystal 30 as transmitted light.

When the thickness of the ferroelectric liquid crystal 30 is 2 μm, the response speed is about 100 μsec at room temperature, which is much higher than that of a TN liquid crystal which normally has a response speed of about several tens of milliseconds. Therefore, a high-speed shutter operation can be realized.

The configuration of an image display device using such a shutter will be described below. In this image display device, as shown in FIG. 8, the illumination light emitted from the illumination light source 1 enters an illumination optical system 2 having functions such as correction of a light beam cross-sectional shape, uniform intensity, and divergence angle control. . The illumination optical system 2 has an optical function called a P-S polarization converter, which has a function of aligning a non-polarized light beam with either P-polarized light or S-polarized light with an efficiency of 50% or more. Blocks may be included.

In this embodiment, the illumination optical system 2
The illumination light that has passed through has a polarization state in which the electric vector oscillates mainly in a direction perpendicular to the paper surface, that is, is S-polarized light with respect to the reflection surface of the dichroic mirror 40 that reflects red light. The illumination light emitted from the illumination optical system 2 is deflected by 90 degrees in the traveling direction of only the red light component by a red light reflecting dichroic mirror 40.
1 and a polarizing beam splitter for red light (PB
S) The light is incident on 42. The illumination light is incident on the dielectric film 42a of the polarization beam splitter 42, where only the S-polarized light component is reflected, and the reflected light T
The light enters the N liquid crystal panel 43. The illumination light whose polarization state is modulated and reflected by the reflection type TN liquid crystal panel 43 for red light is incident again on the dielectric film 42a of the polarization beam splitter 42, where it is detected so that only the P-polarized light is transmitted therethrough. The polarization modulation is converted to a luminance modulation. The emission light converted into the luminance modulation enters the cross dichroic prism 44.

On the other hand, the illumination light transmitted through the red light reflecting dichroic mirror 40 is incident on a green light reflecting dichroic mirror 45 disposed subsequently. Here, only the green light is reflected, and the remaining blue light components are transmitted. The separated green light and blue light are respectively subjected to polarization beam splitters 46 and 47 by the polarization beam splitters 46 and 47 in the same manner as the red light component described above.
Reflection type TN liquid crystal panel for green light, which reflects only polarized light
8 and the reflection type TN liquid crystal panel 49 for blue light. The illumination light whose polarization state is modulated and reflected by the reflection type TN liquid crystal panel for green light 48 and the reflection type TN liquid crystal panel 49 for blue light is again reflected by the polarization beam splitters 46 and 4.
No. 7 are incident on the dielectric films 46a and 47a, where the detection is performed so that only the P-polarized light is transmitted, and the polarization modulation is converted into the luminance modulation. The emission light converted into the luminance modulation enters the cross dichroic prism 44. According to the displayed image
The three illumination lights of red, green, and blue modulated by the reflection type TN liquid crystal panels 43, 48, and 49 for each color light, respectively,
The light is synthesized by the cross dichroic prism 44 and then enters the optical shutter 22 made of ferroelectric liquid crystal. At this time, when the optical shutter 22 is open, the light incident on the optical shutter 22 subsequently enters the projection optical system 8 and forms an image on the screen 9.

The image display apparatus has a system front roller 12 to which an image signal 10 is input, a reflection type TN liquid crystal panel drive control circuit 50 and an optical shutter drive control circuit 51 controlled by the system front roller 12. Are provided. An infrared light emitting diode (LE) is provided near the projection light emitting portion 8a of the projection optical system 8.
D) and a short-range object detection sensor 20 composed of a phototransistor.

In this image display device, the image signal 1
When 0 is input to the system front roller 12, the system front roller 12
Perform synchronization signal generation, image signal processing, gamma correction, etc.
Control signals are output to the reflection type TN liquid crystal panel drive control circuit 50 and the optical shutter drive control circuit 51, respectively. The reflection type TN liquid crystal panel drive control circuit 50 and the optical shutter drive control circuit 51 perform conversion to the respective liquid crystal panel drive signals, rearrangement, and the like based on the input control signal, and perform the reflection type TN liquid crystal panel 43, Signals are sent to 48, 49 and the optical shutter 22.

An output signal from the short distance object detection sensor 20 is also input to the system front roller 12. Here, if any object appears in the vicinity of the projection light emitting unit 8a of the projection optical system 8 and the output value of the short-range object detection sensor 20 falls within the indicated range, the system shutter 12 causes the optical shutter 12 to operate. Drive control circuit 5
1, a control signal for closing the optical shutter 22 is given. Then, the optical shutter 22 is switched to the closed state, and the illumination light no longer enters the projection optical system 8. At this time, there may be cases where the illumination light cannot be completely blocked due to the performance of the optical shutter 22,
Considering the output of a general household projector, it is sufficient that a long trust ratio of at least about 100: 1 is maintained.

In this embodiment, since the operating speed of the TN liquid crystal panel is relatively low,
An optical shutter made of ferroelectric liquid crystal capable of high-speed operation was used. This makes it possible to reduce the integrated amount of the energy of light that accidentally enters the eye.

[Third Embodiment] The image display apparatus according to the present invention is not limited to the configuration having the projection optical system as in the above-described embodiment, but is configured as a laser scan projector as shown in FIG. You can also. Also in this case, regarding the configuration and the location of the object sensing means and the setting of “all black display” when an object is detected, or the blocking of the illumination light by the optical shutter, the respective configurations described above. Although it can be applied as it is, here, a configuration of the image display device in which the amount of projected light radiation is attenuated by turning off the light source will be described.

As shown in FIG. 9, this image display device
It has red, green, and blue laser light sources 52, 53, and 54, respectively.
The laser beams emitted from these laser light sources 52, 53, 54 are first shaped into parallel beams by collimator lenses 55, 56, 57. Subsequently, the light is condensed by the focusing lenses 58, 59, and 60 on the incident surfaces of acousto-optic devices (AOMs) 61, 62, and 63 serving as light output modulating means.

The acousto-optic devices 61, 62, 63
Ultrasonic waves are poured into a medium, and a compressional wave having a refractive index is formed by utilizing the photoelastic effect thereby, and this is used as a diffraction grating. By modulating the intensity and frequency of the ultrasonic wave to be injected, the diffraction intensity and diffraction angle can be modulated. In this acousto-optic element, the intensity modulation can be performed by blocking the zero-order light and transmitting the diffracted light.

In this image display device, the acousto-optic devices 61, 62 and 63 are modulated according to the image signal, thereby performing a series of brightness modulation of the illumination light. Acousto-optic device 6
The red, green, and blue laser beams passing through 1, 62, and 63 are again shaped into parallel beams by collimator lenses 64, 65, and 66, respectively. Thereafter, a dichroic mirror 67 for reflecting blue-green light and a dichroic mirror 6 for reflecting green light are provided.
8. After passing through the aluminum total reflection mirror 69, these red, green, and blue parallel lights have the same optical axis and are incident on a galvanometer 72 serving as a scanning means via mirrors 70 and 71. The laser light whose optical axis is aligned is scanned in the vertical direction of the screen 9, that is, in the direction perpendicular to the scanning lines. Next, the laser light is applied to the relay lens system 73.
Then, the light enters a polygon mirror 74 serving as a scanning unit, and is scanned by the polygon mirror 74 in the horizontal direction, that is, in the scanning line direction. The laser light scanned in the vertical and horizontal directions of the display screen is emitted from an opening 76 provided in the apparatus housing 75 and projected on the screen 9.

The image display apparatus includes a system front roller 12 to which the image signal 10 is input, laser light source power control circuits 78, 79, 80 controlled by the system controller 12, and a system controller 12
Acousto-optic devices 61 and 6 controlled by control signals from
AOM control circuits 81, 82, 83 for controlling
A galvanometer control circuit 84 controlled by a control signal from the system front roller 12 to control the galvanometer 72, and a polygon mirror control circuit 85 controlled by a control signal from the system controller 12 to control the polygon mirror 74. Is provided.
Further, an infrared LED 22, a CCD light receiving element 86, and an imaging lens 87 are provided.

In this image display device, the image signal 1
When 0 is input to the system controller 12, the system controller 12 performs synchronization signal generation, image signal processing, gamma correction, and the like based on the input signal, and performs laser light source power control circuits 78, 79, 80, and an AOM control circuit. 81, 82, 83, galvanometer control circuit 8
4. Output a control signal to the polygon mirror control circuit 85.

Laser light source power supply control circuits 78, 7
Reference numerals 9 and 80 control the red, green and blue laser light sources 52, 53 and 54 based on the input control signals, and control the light output. Also, the AOM control circuit 81,
82 and 83 drive the acousto-optical elements 61, 62 and 63 based on the input control signal, and perform luminance modulation of each color light according to the image signal 10. Galvanometer control circuit 8
The laser beam is scanned on the screen 9 to display an image by controlling the drive of the galvanometer 72 and the polygon mirror 74 based on a control signal such as a synchronization signal sent from the system controller 12 and the polygon mirror control circuit 85 and the system controller 12. I do.

The system controller 12 is also a light output control unit, and receives an output signal from the CCD light receiving element 86. As shown in FIG. 9, the infrared LED 22, the CCD light receiving element 86, and the imaging lens 87 are provided with an opening 76 from which a laser beam of a device body 75 of the image display device is emitted.
Is provided in the vicinity. From the infrared LED 22,
Infrared light is emitted in pulses. Also, the CCD light receiving element 86
Is provided with a visible light range cut filter so as to receive only infrared light.

The infrared sampling time of the CCD light receiving element 86 is approximately equal to the light emission time of the infrared LED 22, and the image information sampled at a certain timing is temporarily stored in a memory. Then, a difference operation is performed between the next sample data and the data in the memory. If the difference amount is equal to or more than a certain value, it is determined that some object has entered the photographing area, and the system controller 1
2 is a laser light source power supply control circuit 78, 79, 8
Send a laser emission stop signal to 0. By doing this,
As soon as a human enters the laser light irradiation area, the laser light irradiation is stopped. Note that the imaging area of the CCD light receiving element 86 includes a laser light irradiation range indicated by a solid line B in FIG. 9 as indicated by a broken line A in FIG. Further, an unillustrated infrared ray reaching area emitted from the infrared LED 22 also includes a photographing area of the CCD light receiving element 86. In this image display device, by using infrared light as detection light, it is possible to distinguish an image formed on the screen from an object approaching the screen.

In this image display device, since substantially parallel laser light is emitted from the opening 76, the object detection area is set to be approximately between the opening 76 and the screen 9. In the case of a device having a relatively low object detection area, the object detection area may be set to a narrower range.
Further, in this image display device, the laser light is cut off by controlling the output of the laser light source. However, when it takes time to reduce the output of the laser, a light stop command from the system controller 12 is transmitted to the AOM control circuit 8.
1, 82, 83, and the emission luminance may be reduced by controlling the acousto-optic element.

In this image display device, the object sensing means may be a light receiving element for detecting the reflected light of the laser beam scanned by the scanning means from the object. It may be provided on the screen side to detect that a laser beam forming an image thereon is blocked by an object in at least a certain area. Further, the light receiving element serving as the object sensing means may optically detect an object existing around an image formed on the screen.

When the system controller 12 determines from the output from the object sensing means that an object exists between the scanning means and the screen,
By controlling the galvanometer 72 or the polygon mirror 74, the laser beam may not be scanned in the image display area.

[Fourth Embodiment] An image display apparatus according to the present invention takes an image formed by illumination light projected on a screen by an image pickup means, and outputs the result of this image pickup to a spatial light modulator. It can be configured to compare an input signal and detect the presence of an object between the image display device and the screen based on the comparison result.

In this image display device, as shown in FIG. 10, the illumination light emitted from the illumination light source 1 enters the illumination optical system 2, and corrects the light beam cross-sectional shape, makes the intensity uniform, and controls the divergence angle. And enters the red light reflecting dichroic mirror 40. The illuminating light is deflected by 90 ° in the traveling direction of only the red light component by a red light reflecting dichroic mirror 40, reflected by a mirror 41, and incident on a polarizing beam splitter (PBS) 42 for red light. Illumination light is applied to the dielectric film 42 of the polarization beam splitter 42.
a, where only the S-polarized component is reflected and incident on the reflective TN liquid crystal panel 43 for red light as incident polarized light. The illumination light whose polarization state is modulated and reflected by the reflection type TN liquid crystal panel 43 for red light is incident again on the dielectric film 42a of the polarization beam splitter 42, where it is detected so that only the P-polarized light is transmitted therethrough. The polarization modulation is converted to a luminance modulation. The emission light converted into the luminance modulation enters the cross dichroic prism 44.

On the other hand, the illumination light transmitted through the red light reflecting dichroic mirror 40 is incident on a green light reflecting dichroic mirror 45 disposed subsequently. Here, only the green light is reflected, and the remaining blue light components are transmitted. The separated green light and blue light are respectively subjected to polarization beam splitters 46 and 47 by the polarization beam splitters 46 and 47 in the same manner as the red light component described above.
Reflection type TN liquid crystal panel for green light, which reflects only polarized light
8 and the reflection type TN liquid crystal panel 49 for blue light. The illumination light whose polarization state is modulated and reflected by the reflection type TN liquid crystal panel for green light 48 and the reflection type TN liquid crystal panel 49 for blue light is again reflected by the polarization beam splitters 46 and 4.
No. 7 are incident on the dielectric films 46a and 47a, where the detection is performed so that only the P-polarized light is transmitted, and the polarization modulation is converted into the luminance modulation. The emission light converted into the luminance modulation enters the cross dichroic prism 44. According to the displayed image
The three illumination lights of red, green, and blue modulated by the reflection type TN liquid crystal panels 43, 48, and 49 for each color light, respectively,
The light is synthesized by the cross dichroic prism 44 and then enters the optical shutter 22 made of ferroelectric liquid crystal. At this time, when the optical shutter 22 is open, the light incident on the optical shutter 22 enters the projection optical system 8 via the (1/4) λ plate 88 constituting the optical path dividing means, and Imaged on top.

The illumination light imaged on the screen 9 is
It is in a circularly polarized state by the action of the (1/4) λ plate 88, and is projected and reflected on the screen 9,
The light returns to the projection optical system 8 in a state of circular polarization in a direction opposite to that when the light is projected. Further, returning to the (1/4) λ plate 88,
By passing through the (1/4) λ plate 88, the light becomes linearly polarized light in a direction orthogonal to the polarization direction when emitted from the cross dichroic prism 44, and returns to the cross dichroic prism 44. This return light
The light passes through the cross dichroic prism 44 and is incident on a polarization beam splitter 46 for green light which constitutes an optical path splitting unit located behind the cross dichroic prism 44.
6 reflected by the dielectric film 46a and serving as an imaging unit.
D (individual imaging device) 89 is incident.

The CCD 89 receives light at a position conjugate with the reflective TN liquid crystal panel 48 as a spatial light modulator through the dielectric film 46a of the polarization beam splitter 46 as an optical path splitting means. That is, the CCD 89 captures an image formed by the illumination light formed on the screen 9 using the projection optical system 8 as an imaging lens.

The image display apparatus has a system front roller 12 to which an image signal 10 is input, a reflection type TN liquid crystal panel drive control circuit 50 and an optical shutter drive control circuit 51 controlled by the system front roller 12. Are provided. Further, the system front roller 12 includes a comparison operation circuit 1 serving as comparison operation means for comparing the image signal 10 with an output signal from the CCD 89.
2a.

In this image display device, the image signal 1
When 0 is input to the system front roller 12, the system front roller 12
Perform synchronization signal generation, image signal processing, gamma correction, etc.
Control signals are output to the reflection type TN liquid crystal panel drive control circuit 50 and the optical shutter drive control circuit 51, respectively. The reflection type TN liquid crystal panel drive control circuit 50 and the optical shutter drive control circuit 51 perform conversion to the respective liquid crystal panel drive signals, rearrangement, and the like based on the input control signal, and perform the reflection type TN liquid crystal panel 43, Signals are sent to 48, 49 and the optical shutter 22.

The image signal 10 is input to the comparison operation circuit 12 a of the system front roller 12, and the output signal from the CCD 89 is input via the CCD drive circuit 90. By comparing the image signal 10 with the output signal from the CCD 89, the presence or absence of an object between the projection optical system 8 and the screen 9 can be detected. Here, if any object appears in the vicinity of the projection light emitting portion 8a of the projection optical system 8 and the difference between the image signal 10 and the output signal from the CCD 89 becomes such a level, the system front roller 12
Thus, a control signal for closing the optical shutter 22 is given to the optical shutter drive control circuit 51. Then, the optical shutter 22 is switched to the closed state, and the illumination light no longer enters the projection optical system 8.

Also in this image display device, a surface emitting laser, a ferroelectric liquid crystal panel, a D
Various types such as an MD panel can be used.

The imaging means is configured to capture an image via an imaging optical system (including the same optical system) whose optical axis coincides with the optical axis of the projection optical system as in the above embodiment. However, the imaging may be performed via an imaging optical system independent of the projection optical system.

As will be described later, the optical path dividing means may be constituted by using a band-pass filter. In this case, the imaging means receives a component outside the visible wavelength range.

Further, the imaging means may receive the light projected onto the screen by the projection optical system, reflected on the screen and returned to the projection optical system in a time-division manner only within a predetermined period.

The imaging means may be disposed around the spatial light modulator. In this case, the imaging means uses the projection optical system to adjust the periphery of the image formed on the screen. An image will be taken.

When the system controller 12 serving as the projection light output control means determines that an object exists between the projection optical system 8 and the screen 9 based on the output from the comparison operation circuit 12a, Alternatively, the illumination light source 1 may be turned off.
An optical path blocking element may be provided in the optical path leading to and the illumination light may be blocked, or the spatial light modulating element may be controlled to perform full screen black display.

[Fifth Embodiment] As described above, in the image display device according to the present invention, a bandpass filter can be used as the optical path dividing means. In this case, the imaging unit may receive a component outside the visible wavelength range.

This image display device includes an illumination light source 1 as shown in FIG. The illumination light emitted from the illumination light source 1 enters the illumination optical system 2. Illumination optical system 2
Performs correction of a light beam cross-sectional shape of incident illumination light, uniformity of intensity, control of a divergence angle, and the like. The illumination light that has passed through the illumination optical system 2 is reflected by the mirror 3 and deflected by 90 °.
The light passes through the color wheel 4 and enters the total reflection prism 5. The color wheel 4 time-divides white light emitted from the illumination light source 1 into red (R), green (G), and blue (B) spectral components. By such time division, a color image can be displayed by a so-called “field sequential color method”.

The illumination light totally reflected by the total reflection surface 5a of the total reflection prism 5 enters a DMD (digital micromirror display) panel 6 which is a spatial light modulator. The DMD panel 6 has an aluminum micro mirror corresponding to each pixel having a binary tilt angle,
It is possible to switch between light and dark for each pixel. The reflected light from these aluminum micromirrors passes through the optical path length correction prism 7 and the dichroic mirror 91 serving as a bandpass filter, passes through the projection optical system 8, and forms an image on the screen 9.

The illumination light formed on the screen 9 is reflected on the screen 9 and returns to the projection optical system 8. Further, returning to the dichroic mirror 91, only a component in a predetermined wavelength range outside the visible wavelength range is reflected by the dichroic mirror 91, and the CC serving as an imaging unit is reflected.
D (individual imaging device) 89 is incident. That is, CCD
Reference numeral 89 denotes an image formed by the illumination light formed on the screen 9 using the projection optical system 8 as an imaging lens.

In this image display device, the DMD panel 6 is controlled by a system controller (control circuit) 12 so as to modulate incident illumination light in accordance with the image signal 10. That is, the image signal 10 which is an analog signal is converted into a digital signal via the A / D converter 11 and is input to the system controller 12. The system front roller 12 controls the DMD panel 6 via the DMD drive control circuit 13 according to the input image signal. Also, the system controller 12
Controls the color wheel 4 via the color wheel drive control circuit 14. That is, the system front roller 12 performs synchronization signal generation, image signal processing, gamma correction, and the like based on the input image signal, and outputs control signals to the DMD drive control circuit 13 and the color wheel drive control circuit 14, respectively. I do. DMD drive control circuit 13
And the color wheel drive control circuit 14 converts the control signal into a DMD drive signal based on the input control signal.
Rearrangement, generation of a color wheel motor control current, and the like are performed and sent to the DMD panel 6 and the color wheel 4, respectively, to realize a color image display by the “field sequential color method”. In this image display device, the system front roller 12 drives the CCD 89 via the CCD drive circuit 90, and receives an output signal from the CCD 89.

By comparing the image signal 10 with the output signal from the CCD 89, the presence or absence of an object between the projection optical system 8 and the screen 9 can be detected. Here, if any object appears in the vicinity of the projection light emitting unit 8a of the projection optical system 8 and the difference between the image signal 10 and the output signal from the CCD 89 becomes such a degree, the system controller 12 It is determined that some object exists near the illumination light emitting portion 8a of the projection optical system 8.

When the system controller 12 determines that there is any object near the illumination light emitting portion 8a of the projection optical system 8, the system controller 12 issues a command of "display all black" to the DMD.
The data is sent to the drive control circuit 13 so that the next time the data of the DMD panel 6 is rewritten, a state of black display on the entire surface, that is, a state where all the illumination light does not reach the projection optical system 8 is set. DM
Since the D panel 6 can operate at a very high speed, it is possible to quickly switch to the full black display state under the control of the system controller 12.

[Sixth Embodiment] The image display apparatus according to the present invention may use a transmission type liquid crystal display device as the spatial light modulator. Further, as described above, the imaging means is disposed around the spatial light modulator,
As shown in FIG. 13, the periphery of an image formed on the screen 9 may be captured by the projection optical system 8.

In this image display device, as shown in FIG. 12, the illumination light emitted from the illumination light source 1 enters the integrator 95, where the intensity is made uniform and the divergence angle is controlled. The polarization converter 96 aligns the polarized light with either the P-polarized light or the S-polarized light with an efficiency of 50% or more. Then, the light enters the dichroic mirror 45 that transmits blue light through the mirror 41 and the relay lens 97. This illuminating light travels straight through the blue light component as it is by the dichroic mirror 45 that transmits blue light, and the mirror 9
The light is reflected at 8 and is incident on a transmission type liquid crystal panel 92 for blue light. The emitted light whose luminance has been modulated by the blue light transmission type liquid crystal panel 92 enters the cross dichroic prism 44.

On the other hand, the illumination light reflected by the blue light reflecting dichroic mirror 45 is incident on a green light reflecting dichroic mirror 40 which is arranged subsequently. Here, only the green light is reflected, and the remaining red light component is transmitted. The separated green light and red light are directly or reflected by the mirrors 99 and 100, respectively, similarly to the above-described blue light component, and are transmitted through the green light transmission liquid crystal panel 93 and the red light transmission liquid crystal panel 94. Respectively. Transmissive liquid crystal panel 93 for green light and transmissive liquid crystal panel 94 for red light
The emitted light whose luminance has been modulated by the light enters the cross dichroic prism 44. The three illumination lights of red, green, and blue modulated by the transmission type liquid crystal panels 92, 93, and 94 for each color light in accordance with the display image are combined by the cross dichroic prism 44, and are then arranged. The light enters an optical shutter 22 made of dielectric liquid crystal. At this time, when the optical shutter 22 is open, the light incident on the optical shutter 22 enters the projection optical system 8 and forms an image on a screen.

The illumination light formed on the screen is reflected on the screen 9 and returns to the projection optical system 8. Further, the return light returns to the cross dichroic prism 44, passes through the cross dichroic prism 44, and is disposed behind the transmission type liquid crystal panel 9 for green light.
A CCD (solid-state image sensor) serving as an image pickup means disposed around the liquid crystal panel 3 and flush with the transmission type liquid crystal panel 93 for green light.
It is incident on 89. That is, as shown in FIG. 13, the CCD 89 captures an image of the peripheral portion 9b of the image area 9a formed by the illumination light formed on the screen 9 using the projection optical system 8 as an imaging lens.

The image display device is provided with a system front roller 12 to which the image signal 10 is inputted, and a liquid crystal panel drive control circuit 50 and an optical shutter drive control circuit 51 controlled by the system front roller 12. Have been.

In this image display device, the image signal 1
When 0 is input to the system front roller 12, the system front roller 12
Perform synchronization signal generation, image signal processing, gamma correction, etc.
A control signal is output to each of the liquid crystal panel drive control circuit 50 and the optical shutter drive control circuit 51. The liquid crystal panel drive control circuit 50 and the optical shutter drive control circuit 51 perform conversion, rearrangement, and the like into each liquid crystal panel drive signal based on the input control signal, and transmit each liquid crystal panel 92, 93, 94, A signal is sent to the optical shutter 22.

The system front roller 12 has C
An output signal from the CD 89 is input. Image information sampled by the CCD 89 at a certain timing is
Once stored in a memory not shown. Then, the system controller 12 performs a difference operation between the next sample data and the data in the memory, and when the difference amount is equal to or more than a certain value, determines that an object has entered the imaging region.

When an object appears in the peripheral portion 9b of the image area 9a, a control signal for closing the optical shutter 22 is given to the optical shutter drive control circuit 51 by the system front roller 12. Then, the optical shutter 22 is switched to the closed state, and the illumination light no longer enters the projection optical system 8.

[Seventh Embodiment] An image display apparatus according to the present invention has a laser light source as shown in the above-mentioned "third embodiment", and a laser beam emitted from this laser light source. In the case where the image is formed by scanning the image on the screen by the scanning unit, the image formed on the screen is imaged by the imaging unit, and the result of this imaging is compared with the input image signal. According to the comparison result, it is possible to detect the presence of an object between the image display device and the screen.

In this case, since there is no projection optical system, the imaging means captures an image on the screen via a separate imaging optical system (imaging lens). Then, as in the embodiment described above, the input signal to the light output modulation means corresponding to the image signal and the image signal output from the imaging means are compared by the comparison operation means, and the light output control means And controlling the output of the laser beam scanned by the scanning means according to the comparison result by the comparison calculation means.

In this case, the output of the laser light is controlled by controlling the output of the laser light source, reducing the emission luminance by controlling the light output modulating means such as the acousto-optic element, or scanning the galvanometer or polygon mirror. By controlling the means, it is possible to perform the above-described various operations such as not to scan the image display area with the laser light.

[0094]

As described above, in the image display device according to the present invention, the projection optical system of the image display device configured as a front projection type, or the illumination light emitted from the opening of the device housing, or In addition, it is possible to prevent laser light from being directly incident on the naked eye by mistake.

Such an operation can be realized by “black display” in the spatial light modulator, or by reducing or extinguishing the radiation amount of the light source. Only the object sensing means such as the light emitting means and the imaging means need be provided, and the configuration of the apparatus is not complicated.

Further, when the spatial light modulator or the light source cannot follow a sufficiently high-speed modulation, an optical shutter capable of high-speed modulation is used, so that the invention can be applied to a front-projection image display device having various structures. Has become.

Further, in this image display device, light outside the visible wavelength range such as infrared light or microwaves is used to detect an object, or light outside the visible wavelength range of light forming an image is used. By sensing the object by comparison or change, the projected light can be distinguished between the image on the screen and the actual object without being recognized as noise by the observer and without affecting the image quality of the displayed image. Can be controlled.

That is, the present invention relates to a front projection type image display device, in which light projected on a screen via a projection optical system or the like is prevented from being accidentally directly incident on human eyes. It is possible to provide an image display device which does not affect the body organs such as the cornea and the retina even when a high power is used or a laser light source is used.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration of an image display device according to a first embodiment of the present invention.

FIG. 2 is a front view illustrating a configuration of a DMD panel serving as a spatial light modulator in the image display device.

FIG. 3 is a front view and a side view showing a configuration of an aluminum micro mirror of the DMD panel.

FIG. 4 is a perspective view showing the operation of the aluminum micro mirror.

FIG. 5 is a side view showing the operation of the DMD panel.

FIG. 6 is a side view showing a configuration of a photocoupler serving as an object sensing means in the image display device.

FIG. 7 is a cross-sectional view illustrating a configuration and operation of a ferroelectric liquid crystal panel serving as a shutter that blocks illumination light in an image display device according to a second embodiment of the present invention.

FIG. 8 is a side view illustrating a configuration of an image display device according to a second embodiment of the present invention.

FIG. 9 is a side view illustrating a configuration of an image display device according to a third embodiment of the present invention.

FIG. 10 is a side view illustrating a configuration of an image display device according to a fourth embodiment of the present invention.

FIG. 11 is a side view illustrating a configuration of an image display device according to a fifth embodiment of the present invention.

FIG. 12 is a side view illustrating a configuration of an image display device according to a sixth embodiment of the present invention.

FIG. 13 is a front view showing a relationship between a region where an object is detected and a region where an image is displayed in the image display device.

FIG. 14 is a side view showing a configuration of a conventional image display device.

FIG. 15 is a side view showing another example of the configuration of the conventional image display device.

[Explanation of symbols]

1 illumination light source, 6 DMD panel, 8 projection optical system, 9
Screen, 10 image signals, 12 system controller, 12a comparison operation circuit, 20 photocoupler, 2
2 Optical shutter, 43, 48, 49 Reflective TN liquid crystal panel, 46 polarizing beam splitter, 52, 53, 54
Laser light source, 61, 62, 63 acousto-optic device, 72
Galvano mirror, 74 polygon mirror, 86 CCD
Light receiving element, 88 (1/4) λ plate, 89 CCD, 91
Dichroic mirror, 92, 93, 94 transmissive liquid crystal panel,

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/11 502 G02F 1/11 502 5C058 1/13 505 1/13 505 5C080 1/141 G09F 9/00 360Z 5C082 G09F 9/00 360 G09G 3/20 670Z 5F073 G09G 3/20 670 680 680C 5F089 680 3/34 D 5G435 3/34 3/36 3/36 5/00 550C 5/00 550 H01L 31/12 E01 / 12 G H01S 5/183 H01S 5/183 H04N 5/74 B H04N 5/74 G02F 1/137 510 F term (reference) 2H045 AA01 BA12 BA24 DA12 2H079 AA02 AA04 BA01 CA22 CA24 DA08 EB21 FA01 FA03 FA04 2H088 EA15 EA16EA33 HA13 HA17 HA20 HA28 JA05 JA17 2H099 AA12 BA09 CA02 DA05 5C006 AA22 AF61 BB11 BD 01 BF39 EA01 EA03 EC11 5C058 AA05 AA06 BA23 BA35 BB25 EA02 EA05 EA12 EA27 EA31 5C080 AA09 AA10 CC03 CC06 DD01 DD17 JJ02 JJ06 5C082 AA21 DD34 CB01 CB03 MM08 5F073 AB17 5BB02A02 BA17 BB02 BB08 DD09 DD10 FF05 FF15 GG01 GG03 GG04 GG08 GG10 GG28 GG46

Claims (55)

[Claims] An illumination light source; a spatial light modulation element for modulating illumination light emitted from the illumination light source in accordance with an input signal; and projection optics for projecting the illumination light modulated by the spatial light modulation element onto a screen. System, projection light output control means for controlling the output of illumination light projected by the projection optical system, and object sensing means for sensing the presence of an object between the projection optical system and the screen and outputting a sensing result An image display device, wherein the projection light output control means controls an output of illumination light projected by the projection optical system according to an output from the object sensing means. 2. The image display device according to claim 1, wherein the illumination light source and the spatial light modulator are surface emitting lasers. 3. The object sensing means is a photocoupler having a light emitting element and a light receiving element, wherein the light emitted from the light emitting element detects reflected light from an object by the light receiving element. The image display device according to claim 1, wherein: 4. The image display device according to claim 3, wherein the light emitting element is an infrared light emitting diode. 5. The image display device according to claim 1, wherein the object sensing means is a light receiving element that detects a reflected light of the illumination light projected by the projection optical system from the object. 6. The image display device according to claim 5, wherein the light receiving element is an image sensor. 7. The image display device according to claim 5, wherein the light receiving element is provided around an illumination light projection port of the projection optical system. 8. The object detecting means comprises a microwave transmitting device and a microwave receiving device, and detects a reflected wave of the microwave emitted from the microwave transmitting device from the object by the microwave receiving device. The image display device according to claim 1, wherein: 9. The object sensing means is a light receiving element for detecting that at least a part of illumination light projected by the projection optical system and forming an image on a screen is blocked by an object. 2. The image display device according to 1. 10. The image display device according to claim 9, wherein the object sensing means is a light receiving element arranged on a screen side. 11. The image display device according to claim 1, wherein the object sensing means is a light receiving element for optically detecting an object existing around an image formed on the screen. 12. An image display apparatus according to claim 11, wherein said object sensing means receives light via an imaging optical system whose optical axis coincides with said projection optical system. 13. The apparatus according to claim 12, wherein the object sensing means receives the light through at least a part of the projection optical system.
The image display device as described in the above. 14. The image display device according to claim 13, wherein the object sensing means is a light receiving element arranged on a screen side. 15. The projection light output control means turns off the illumination light source when it is determined from the output from the object detection means that an object exists between the projection optical system and the screen. The image display device according to claim 1, wherein: 16. The projection light output control means, when it is determined from the output from the object detection means that an object exists between the projection optical system and the screen, from the illumination light source to the projection optical system. 2. The image display device according to claim 1, wherein an optical path blocking element disposed in an optical path leading to the optical path blocks illumination light. 17. The projection light output control means, when it is determined from the output from the object detection means that an object exists between the projection optical system and the screen, the light is projected by the projection optical system. 2. The image display device according to claim 1, wherein a shutter for blocking the illumination light is closed. 18. The image display device according to claim 17, wherein the shutter is a ferroelectric liquid crystal panel. 19. The projection light output control means controls the spatial light modulation element when it is determined from the output from the object detection means that an object exists between the projection optical system and the screen. 2. The image display device according to claim 1, wherein the entire screen is displayed in black. 20. An illumination light source; a spatial light modulation element for modulating illumination light emitted from the illumination light source according to an input signal; and projection optics for projecting the illumination light modulated by the spatial light modulation element onto a screen. System, projection light output control means for controlling the output of illumination light projected by the projection optical system, imaging means for capturing an image formed by the illumination light projected on the screen and outputting an image signal, Comparing an input signal to the spatial light modulation element with an image signal output from the imaging unit, and a comparison operation unit that outputs a comparison result, wherein the projection light output control unit includes: An image display device, wherein an output of illumination light projected by the projection optical system is controlled according to an output. 21. The image display device according to claim 20, wherein the illumination light source and the spatial light modulator are surface emitting lasers. 22. The image display apparatus according to claim 20, wherein the image pickup means picks up an image via an image pickup optical system whose optical axis is matched with the optical axis of the projection optical system. 23. The image display apparatus according to claim 20, wherein said image pickup means picks up an image via a projection optical system. 24. The image display device according to claim 23, wherein the image pickup means is provided around the spatial light modulator. 25. An image pickup means, at a position conjugate to a spatial light modulation element via an optical path splitting means, reflects light projected on a screen by a projection optical system, reflected on the screen and returned to the projection optical system. The image display device according to claim 23, which receives light. 26. The image display device according to claim 25, wherein the imaging means receives a component outside the visible wavelength range. 27. The image display device according to claim 26, wherein the optical path dividing means includes a λ / 4 plate, a polarizing beam splitter, and a band pass filter. 28. The image pickup means receives light projected on a screen by a projection optical system, reflected on the screen and returned to the projection optical system in a time-division manner only within a predetermined period. The image display device according to claim 20. 29. The projection light output control means turns off the illumination light source when it is determined from the output from the comparison operation means that an object exists between the projection optical system and the screen. The image display device according to claim 20, characterized in that: 30. The projection light output control means, when it is determined from the output from the comparison operation means that an object exists between the projection optical system and the screen, from the illumination light source to the projection optical system. 21. The image display device according to claim 20, wherein an optical path blocking element disposed in an optical path leading to the optical path blocks illumination light. 31. The projection light output control means, when it is determined from the output from the comparison operation means that an object exists between the projection optical system and the screen, the light is projected by the projection optical system. 21. The image display device according to claim 20, wherein a shutter for blocking illumination light is closed. 32. The image display device according to claim 31, wherein the shutter is a ferroelectric liquid crystal panel. 33. The projection light output control means controls the spatial light modulation element when it is determined from the output from the comparison operation means that an object exists between the projection optical system and the screen. 21. The image display device according to claim 20, wherein the entire screen is displayed in black. 34. A laser light source; light output modulating means for modulating an optical output of the laser light according to an input signal; scanning means for scanning a laser light emitted from the laser light source on a screen; Light output control means for controlling the light output of the laser light scanned by the means, and object sensing means for sensing the presence of an object between the laser light source and the screen and outputting a sensing result, wherein the light output An image display device, wherein the control means controls the output of laser light scanned by the scanning means according to the output from the object sensing means. 35. The object sensing means is a photocoupler having a light emitting element and a light receiving element, wherein the light emitted from the light emitting element detects reflected light from the object by the light receiving element. The image display device according to claim 34, wherein: 36. The image display device according to claim 35, wherein the light emitting element is an infrared light emitting diode. 37. The image display device according to claim 34, wherein the object sensing means is a light receiving element for detecting a reflected light of the laser beam scanned by the scanning means from the object. 38. The image display device according to claim 37, wherein the light receiving element is an imaging element. 39. The light receiving device according to claim 37, wherein the light receiving element is disposed around an illumination light projection port of the projection optical system.
The image display device as described in the above. 40. An object sensing means comprising a microwave transmitting device and a microwave receiving device, wherein the microwave receiving device detects a reflected wave of the microwave emitted from the object by the microwave receiving device. 35. The image display device according to claim 34, wherein: 41. The object detecting means is a light receiving element for detecting that a laser beam scanned by the scanning means and forming an image on a screen is blocked by an object in at least a certain area. The image display device according to claim 34. 42. The image display device according to claim 41, wherein the object sensing means is a light receiving element arranged on a screen side. 43. The image display device according to claim 34, wherein the object sensing means is a light receiving element for optically detecting an object existing around an image formed on the screen. 44. The image display device according to claim 43, wherein the object sensing means is a light receiving element arranged on a screen side. 45. The light output control means turns off the laser light source when it is determined from the output from the object detection means that an object exists between the scanning means and the screen. 35. The image display device according to claim 34. 46. The light output control means, when it is determined from the output from the object sensing means that an object exists between the scanning means and the screen, the laser light scanned by the scanning means. 35. The image display device according to claim 34, wherein the shutter that shuts off is closed. 47. An optical output control means, when it is determined from the output from the object detecting means that an object exists between the scanning means and the screen, in an optical path from the laser light source to the scanning means. 35. The optical path cutoff device disposed in the device is set in a state of blocking laser light.
The image display device as described in the above. 48. The light output control means controls the light output modulation means when it is determined from the output from the object detection means that an object exists between the scanning means and the screen. 35. The image display device according to claim 34, wherein the entire screen is displayed in black. 49. The light output control means controls the scanning means when it is determined from the output from the object sensing means that an object is present between the scanning means and the screen, thereby controlling the scanning means. 35. The image display device according to claim 34, wherein a laser beam is not scanned in the display area. 50. A laser light source; light output modulating means for modulating an optical output of the laser light according to an input signal; scanning means for scanning a laser light emitted from the laser light source on a screen; Light output control means for controlling the light output of the laser light scanned by the means; imaging means for capturing an image formed by the laser light scanned on the screen and outputting an image signal; Comparing the input signal with the image signal output from the imaging means, and outputting a comparison result. The light output control means performs the scanning in accordance with an output from the comparison operation means. An image display device for controlling an output of a laser beam scanned by the means. 51. The light output control means turns off the laser light source when it is determined from the output from the comparison operation means that an object exists between the scanning means and the screen. 51. The image display device according to claim 50, wherein: 52. The light output control means, when it is determined from the output from the comparison operation means that an object exists between the scanning means and the screen, the laser light scanned by the scanning means. 51. The image display device according to claim 50, wherein a shutter for blocking is set to a closed state. 53. The light output control means, when it is determined from the output from the comparison operation means that an object is present between the scanning means and the screen, in an optical path from the laser light source to the scanning means. 52. The optical path cutoff device disposed in the device is set in a state of blocking laser light.
The image display device as described in the above. 54. The light output control means controls the light output modulation means when it is determined from the output from the comparison operation means that an object exists between the scanning means and the screen. The image display apparatus according to claim 50, wherein the whole screen is displayed in black. 55. The light output control means controls the scanning means when it is determined from the output from the comparison operation means that an object exists between the scanning means and the screen. 51. The image display device according to claim 50, wherein the laser light is not scanned in the display area.