JP2000250001A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical device of high luminance, and whose optical system is simplified. SOLUTION: The optical device is provided with a light supply means 50 for emitting light including plural different kinds of wavelength, one spatial optical modulation element 52, and an optical means 51 for guiding the light emitted from the light supply means 50 to the spatial optical modulation element. The light supply means 50 is constituted of plural light sources 64R, 64G and 64B for individually emitting plural kinds of light having different wavelength, and plural kinds of light having the different wavelength are repeatedly emitted from the light supply means 50 at different timing at a fixed cycle. Thus, the R, G and B light emitted from the light supply means 50 are efficiently used, then the video of high luminance is obtained. The optical system for guiding the light to the spatial optical modulation element is simplified by using the only one spatial optical modulation element 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device suitable for application to a video projector or the like. More specifically, an object of the present invention is to propose an optical device that is small and lightweight and that can obtain a high luminance level by using a single spatial light modulation element and a plurality of light sources that emit light of different wavelengths.

[0002]

2. Description of the Related Art As is well known, a video projector apparatus applies an image signal to a spatial light modulation element such as a two-dimensional liquid crystal element which spatially modulates light, and displays the spatial light modulated image on a screen or the like. Is a video display device adapted to perform enlarged projection on the display means.

In this video projector apparatus, an image of an arbitrary size can be projected on a screen by selecting an optical lens system for projection, and is used in a wide range of fields such as a television image and an advertisement image. I have.

As described above, a two-dimensional liquid crystal element is frequently used as a spatial light modulation element, and a white light source such as a discharge lamp is often used as a light source. Some of the most popular optical devices used in video projector devices will be described with reference to the drawings. Video projector devices are roughly divided into so-called 3D devices using three spatial light modulators.
It is classified into a plate type and a single plate type using only one sheet.

FIG. 14 shows a typical example of a three-plate system. In the video projector device 10, a discharge lamp that emits white light is used as the light source 11, and light emitted from the discharge lamp 11 is separated into R, G, and B primary color lights using a color separation mirror.

First, the outgoing light is guided to a condensing lens 12 and a color separation mirror 13a such as a dichroic mirror to decompose, for example, red outgoing light (R light), and the decomposed R light is converted into a total reflection mirror 14a and a field lens 16R. The liquid crystal panel 17R, which is a spatial light modulation element, is radiated through the LCD. Since the R video signal (modulated video signal) is supplied to the liquid crystal panel 17R, the R light is modulated by this video signal. Therefore, a color separation image (light) of R is obtained from the liquid crystal panel 17R.

Similarly, green emission light (G light) separated by the color separation mirror 13b is applied to a G liquid crystal panel 17G via a field lens 16G. Similarly, the liquid crystal panel 17B is irradiated with the remaining outgoing B light via the relay lens 15, the mirrors 14b and 14c, and the field lens 16B.

Since the corresponding G and B video signals are applied to the respective liquid crystal panels 17G and 17B, G and B color separation images are obtained from the liquid crystal panels 17G and 17B, respectively. The R, G, and B color separation images modulated by the video signal are synthesized again by the color synthesis prism 18, and then enlarged and projected on a screen 20 as an image display unit via a projection lens 19.

[0009] The three-panel video projector apparatus 10 configured as described above can realize a high screen luminance, that is, a high luminance screen. This is the R, G, B liquid crystal panel 17
This is because only light of the corresponding wavelength is incident on the light beams incident on the R, 17G, and 17B, and thus less light is discarded.

However, the optical device constituting the video projector device 10 needs to perform a process of decomposing light into three primary color signals (R, G, B), modulating the light, and synthesizing the light again. And the volume of the device increases accordingly. In other words, in the three-plate system, although a high-luminance image can be obtained, there is a problem that the volume of the device increases and the device becomes relatively expensive.

On the other hand, the single-panel system uses one two-dimensional liquid crystal element which is a spatial light modulation element. There are a plurality of types in this single-plate system. The configuration and the like of each type will be described below.

(1) Color filter method In this method, instead of using white light containing all the wavelength components of R, G, and B as a light source, R, G, and B are used by a color filter 30A.
This type performs G and B light modulation. FIG. 15 shows an example of the configuration. The white light emitted from the light source 11 is
2. Color separation mirrors 23R, 23G, and 2 that separate light into primary color light through a light guide body 21 and a condenser lens 22, respectively.
The light is guided to 3B and is separated and decomposed into R, G, and B primary color lights.

Each primary color light is applied to the liquid crystal panel 17 via the color separation means 30. As the color separating means 30, a color filter for separating into R, G, and B is used.
Each color separation image is enlarged and projected on the screen 20 via a pair of projection lenses 25 and 26 to obtain a color image.

Since the color separation mirror 23R exists, only the light of the wavelength R is incident on the opening corresponding to R of the color filter 30A. Similarly, G light and B light, which have been color-separated by the color separation mirrors 23G and 23B, are incident on the G and B openings provided in the color filter 30A, respectively.

(2) Angle separation method In this method, as shown in FIG.
This type uses a micro lens 30B as the color separation means 30. The details of the microlens 30B are proposed in detail in, for example, Japanese Patent Application Laid-Open No. Hei 4-60538.

As shown in FIG. 16, there are three pixels (openings) 17R, 17G and 17B corresponding to R, G and B, and these three openings 17R and 17G are provided on the front surface of the liquid crystal panel 17. , 17B are arranged in a matrix to form a microlens 30B.

According to the angle of the incident light with respect to these microlens portions 31, each light beam 1,
Allocate a few. For this purpose, the color separation mirrors 23R, 23G, 23B shown in FIG. 15 are arranged with their emission angles changed. Thus, the R, G, and B color separation images are obtained from the liquid crystal panel 17 in the same manner as when the color filter 30A is used.

(3) Color Disk Rotation Method (Color Wheel Method) In this single-plate method, a color wheel 30C as shown in FIG. The color wheel 30 </ b> C includes a rotating disk 32. The rotating disk 32 is divided into three parts in the circumferential direction based on the center of rotation, and is configured as filters 32R, 32G, and 32B that respectively transmit light R, G, and B having different wavelengths.

The light incident on the liquid crystal panel 17 passes through the color wheel 30C and is decomposed into R, G, and B at each time, so that the R, G, and B image signals applied to the liquid crystal panel 17 are applied. The color wheel 30
When supplied in synchronization with the rotation of C, R, G, and B color separated images can be obtained from the liquid crystal panel 17. Color wheel 30
When the rotation speed of B increases to some extent, a color image can be displayed using the afterimage of the human eye.

[0020]

By the way, the optical device of the above-mentioned single-plate type has an advantage that the number of optical elements is small and an inexpensive and lightweight device can be realized regardless of the type. For example, in the three-panel system, it is necessary to provide a color synthesizing prism 18 and the like between the liquid crystal panel 17 and the projection lens 19 in order to combine three colors, whereas in the single-panel system, this color synthesizing part is unnecessary. Therefore, the back focus length of the projection lens 19 can be shortened. This is because the size of the projection lens 19 can be reduced, so that a small and lightweight device can be realized. While they have these advantages, they also have common and unique problems.

A common problem of the single-panel system is that the luminance on the screen is low. In the color filter method, since the light entering the pixels (openings) of the liquid crystal panel 17 is restricted using the color filters 30A, the G and B luminous fluxes incident on the R openings are absorbed by the color filters 30A. As a result, the light use efficiency is degraded, resulting in low luminance.

As a specific problem, since light is absorbed by the liquid crystal panel 17, there is a disadvantage that the temperature of the liquid crystal panel 17 itself rises.

In the angle separation system, no loss of light occurs in the liquid crystal panel 17, but R, G, and R depend on the incident angle.
In order to separate the light to correspond to the three pixels of B,
The angle of the light beam that can enter the liquid crystal panel 17 becomes smaller.
As a result, a large amount of light cannot be incident, and the utilization rate of the light from the light source 11 is reduced, resulting in a reduction in luminance.

An inherent problem is that the color separation mirror 23
High adjustment accuracy of R, 23G, and 23B is required. If the mounting angle is wrong, another light is incident on the corresponding pixel of the liquid crystal panel 17, and a phenomenon of color leakage occurs.

In the color wheel system, light is lost due to light absorption by the color wheel 30C, resulting in lower brightness.

As an inherent problem, since light absorption occurs in the color wheel 30C, it is necessary to take measures against heat. In addition, since the color is separated into R, G, and B by the rotation of the color wheel 30C, the color separation occurs when the observer moves in synchronization with the rotation direction of the color wheel 30C.

For example, as shown in FIG. 17, when the color boundary of the color wheel 30C moves in the Y-axis direction (perpendicular to the paper surface), the observer also moves in the Y-axis direction and in the same direction as the moving direction of the boundary of the rotating disk 32. If it moves in the direction, the color wheel 30C
And the observer's relative speed decreases. Since the projected image is inverted when the projection lens 18 is interposed, in this case, if the observer moves upward, the afterimage effect of the eye is reduced. As a result, in the screen 20, an image that is supposed to project white is seen with each color separated. Actually, even if the observer does not move up and down, each color is seen separately only by shaking the face up and down. This causes image quality degradation.

As described above, the single-plate system can realize a small, lightweight and inexpensive device, but has problems such as low luminance and deterioration of image quality.

Accordingly, the present invention has solved such a conventional problem, and provides a small, lightweight and inexpensive apparatus by employing a single-plate system, and has high brightness and high image quality. The above-mentioned device is realized.

[0030]

In order to solve the above-mentioned problems, in an optical device according to the present invention, a light source means for emitting light including a plurality of different wavelengths, a single spatial light modulation element,
Optical means for guiding light emitted from the light source to the spatial light modulator, wherein the light source means comprises a plurality of light sources that emit light of different wavelengths independently of each other. Light of different wavelengths is repeatedly emitted at a constant period at different times.

In the present invention, the light source means is provided with a light source for emitting light of a plurality of different wavelengths. For example, R, G, and B lights are obtained, respectively. The R, G, and B light from each is irradiated on one spatial light modulator. Since the R, G, and B video signals are supplied to the spatial light modulator corresponding to the R, G, and B lights, the R, G, and B lights are optically modulated by the corresponding video signals. The light-modulated color separation image is enlarged and projected on a screen via an optical system. Since the light from the light source means is light having a specific wavelength,
The light can be used effectively. Therefore, the brightness is high. Also,
Since one spatial light modulator is used, the optical system is simplified.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an optical apparatus according to the present invention applied to the above-described video projector will be described in detail with reference to the drawings.

FIG. 1 is a conceptual diagram of the present invention. In this example, light of wavelengths corresponding to R, G, and B, which are primary color lights in this example, from the light source means 50 irradiates a single two-dimensional liquid crystal panel 52 in this example, which is a spatial light modulation element, through a condenser lens 51. Is done.

A video signal SV to be displayed is supplied to a terminal 61, which is supplied to a color separation processing device 62. A signal synchronized with the R, G, and B lights from the light source means 50 is supplied to a synchronization circuit 60, and a color synchronization signal obtained from the signal is supplied to a color separation processing device 62. As a result, the color video signal supplied to the terminal 61 is separated into R, G, and B video signals (primary color video signals) corresponding to the R, G, and B lights.
The liquid crystal panel 52 is switching-driven based on the separated video signal.

That is, when the R video signal is supplied, the R light is optically modulated by the R video signal. Similarly, G light is optically modulated by the G video signal, and
When the video signal for B is supplied, the incident B light is optically modulated by the video signal for B in synchronization with the supply. The R, G, and B color separation images emitted from the liquid crystal panel 52 are
3, the image is enlarged and projected on a screen 54, which is an image display unit, to obtain a color image.

The light source means 50 emits light containing a plurality of different wavelengths. As the plurality of lights having different wavelengths, three primary color lights R, G, and B are preferable. In this case, the emission phases are shifted from each other by 120 °. The spectrum of the emitted light may be a rectangular wave with a space between each other as shown in FIG. 2A, a triangular wave as shown in FIG. 2B, or a continuous rectangular wave as shown in FIG. 2C. .

For example, when the light source means 50 of FIG. 2A which emits a rectangular wave light at predetermined intervals is used, the R, G, and B video signals output from the color separation processing unit 62 are output as shown in FIG. , A color separation image having a luminance level as shown in FIG. 3B is projected on the screen 54.

FIG. 4 is a block diagram of the video projector device 10 which has described FIG. 1 in more detail.

The light source means 50 includes a plurality of light sources 64R, 64G, and 64B that emit light of different wavelengths independently. The example of FIG. 4 is a case where the same laser diode LD is used as each of the three light sources. The laser diode 64R is a diode that emits R light (for example, a semiconductor laser diode, the same applies hereinafter), and the laser diode 64G is G light. And the laser diode 64B is a diode that emits B light. Each excitation state is controlled by drive pulses Pr, Pg, Pb obtained from a common driver 63.

In FIG. 5, when the unit repetition period is one frame (video frame), this is divided into three, and, for example, a driving pulse Pr for R is applied to the first one-third period to set the laser diode 64R at 1 /. Excited for a period of three cycles. In the next 1/3 period, a drive pulse Pg for G is allocated, and this excites the next laser diode 64G.
Then, a driving pulse Pb for B is allocated to the last 1/3 period.

By exciting the laser diodes 64R, 64G, and 64B at different times in this manner, it is possible to construct the light source means 50 that emits light of different wavelengths whose emission phases are shifted from each other by 120 °. Drive pulses Pr, Pg, P
The drive power of the laser diodes 64R, 64G, 64B can be directly controlled by b. Even when the drive power supply itself is turned on and off, light can be emitted at the pulse interval shown in FIG.

The R light from the laser diode 64R is directly guided to the condenser lens 70 provided on the condenser lens (condensing lens system) 51. The laser diode 64G is a mirror 6
The light is guided to the condensing lens 70 via the light sources 5 and 66 without being light-synthesized. Similarly, the remaining laser diode 64B is guided to the condenser lens 70 via the mirrors 67 and 66.

The condenser lens system 51 includes a light guide 71 and condenser lenses 70 and 72 disposed before and after the light guide 71. First, the R, G, and B light guided to the condenser lens 70 without being light-synthesized is guided into the light guide 71 and is light-synthesized.
The light guide 71 is a square transparent rod having the same end surface shape as the liquid crystal panel 52 as shown in FIG. The light guide 71 can be configured using transparent plastics or transparent glass. As the light guide 71, a rectangular body having a length of about 50 to 150 mm can be used. In the example of FIG. 6, the height is 5 m.
m, a width of 7 mm and a length of 70 mm are used.

Since the R, G, and B lights enter the entrance end surface 71a of the light guide 71 without being light-synthesized, the R, G, and B lights are not combined at this end surface side as shown in FIG. ing. However, since the light is totally reflected and propagated inside the light guide 71, the light emitted from the exit-side end surface 71b is eventually combined (white light) when the eye integration effect is used as shown in FIG. 7B. ). Light guide 71
The R, G, and B light emitted from the
The liquid crystal panel (spatial light modulation element) 52 guides the liquid crystal panel.

On the other hand, the driving pulses Pr, Pg, Pb are also supplied to the synchronizing circuit 60, and the generated synchronizing control signal Sc is supplied to the color separation processing device 62, and the color video signal from the terminal 61 is converted to R signal. , G, and B video signals. Therefore, the synchronization control signal Sc may have the same signal form as in FIG. That is, the R laser diode 64R
During the period in which the drive pulse Pr for driving the G laser diode is obtained, the R separation video signal is output from the color separation processing device 62, and thereafter, similarly, the drive pulse P for driving the G laser diode 64G.
During the period when g is obtained, the video signal for G is output, and
Drive pulse Pb for driving the laser diode 64B
Is obtained, the B video signal is output.

The R, G, and B video signals are supplied to the liquid crystal panel 52.
The light is modulated and a color separation image for R is emitted. Similarly, the G light input in synchronism with the G video signal is modulated to emit a G color separation image, and the B light input by the B video signal is light-modulated to generate a B color separation image. Is emitted.

The emitted color separation images for R, G, and B are enlarged and projected on a screen 54 via a projection lens system 53, whereby light is synthesized on the screen 54 and a desired color image is projected.

As described above, a color image is displayed using all of the R, G, and B lights that are intermittent and that are supplied at a constant period. Condensing lens system 51 and liquid crystal panel 52
No light loss occurs. Therefore, a high-luminance screen can be obtained.

Of course, the advantages of the single-plate system of small size, light weight, and low cost can be utilized as it is.

FIG. 8 shows another embodiment of the light source means 50. In this example, a pair of dichroic mirrors 75 and 76 and a mirror 77 are used, and light is synthesized inside the light source means 50. . The liquid crystal element 52 is radiated through the condensing lens system 51 in a state where the light is combined. Even in such a configuration, since the liquid crystal element 52 is intermittently irradiated with the R, G, and B lights, the same result as in the case of FIG. 4 is obtained.

The light source means 50 shown in the examples of FIGS.
As a light emitting diode (L
ED) can also be used. When the light emission luminance of a single light emitting diode is low, a plurality of light emitting diodes may be collected and used.

FIG. 9 shows a case where light sources of different types are used as a plurality of light sources constituting the light source means 50. Since the configuration other than the light source means 50 is all the same, only the light source means 50 will be described.

In this example, a laser diode is used as the light source 80 that emits B light, and a laser light source such as helium neon (He.Ne) is used as the light source that emits R light.
Can be used.
Another laser light source is used as the light source 82 that emits the G light. As the laser light source 82, a solid laser source using a YAG laser (yttrium aluminum gallium laser) can be used.

In the case of the YAG laser source 82, this YA
The wavelength of light emitted from the G laser source 82 is 1064
When the wavelength is set to nm, a half of the wavelength G (532 nm) is extracted through the wavelength conversion element 86. As the wavelength conversion element 86, a wavelength conversion crystal that is a non-linear crystal, for example, a KTP crystal can be used. G light is applied to mirror 85 and dichroic mirror 8
The R light passes through the dichroic mirror 84 via
The light is combined with the B light via the respective light sources 83.

When a laser light source is used as described above, there are some lasers which cannot modulate output light depending on the voltage or current applied to the laser. He / Ne laser source 81 or Y
The AG laser source 82 corresponds to this. In such a case, the emission phase can be controlled using a so-called Q switch using the resonance sharpness Q. The solid-state laser light source using the Q switch will be described below.

FIG. 10 shows a configuration example of the YAG laser source 82.

In the case of the YAG laser source 82, a semiconductor laser 90 for excitation is used. In this example, a semiconductor laser that oscillates at an excitation wavelength of 808 nm is used for outputting G light. The excitation laser light is guided to a laser resonator 94 using an optical fiber 92.

The laser resonator 94 has a housing 95, and a transmission mirror 96 is partially disposed on one side thereof, and a transmission mirror 98 is also disposed on the other side opposite thereto.
One mirror 96 is a mirror that transmits a specific wavelength (808 nm) and reflects another specific wavelength (1064 nm). The other mirror 98 is 1064 nm
Is a mirror that partially transmits laser light having a wavelength of

Between these mirrors 96 and 98, there is a YAG crystal 100 functioning as a laser oscillator, in other words, functioning as an optical resonator, and between the YAG crystal 100 and the mirror 98, an acousto-optic modulator, so-called. A Q switch 102 is provided. The Q switch 102 functions as a switch capable of controlling the resonance sharpness Q, that is, the degree of loss of the YAG crystal 100, and a switching signal of a predetermined frequency is supplied from a sine wave oscillator 104 provided outside.

The operation of the thus configured YAG laser source 82 will now be described.

When the Q switch 102 is off, the loss of the YAG crystal 100 as the laser medium increases, and the energy of the light supplied via the mirror 96 is stored inside the YAG crystal 100.

The Q switch 10 is switched by a switching signal.
When 2 is turned off, the loss of the YAG crystal body 100 is reduced. Therefore, when the laser oscillation threshold is exceeded, all the stored energy stored up to that point is emitted as laser light. This makes it possible to obtain a pulsed laser oscillation output that is pulsed light and has a large peak value.

When a light source that emits infrared laser light is used as the semiconductor laser 90 for excitation, the YAG crystal 100 is excited by the infrared laser light and oscillates. The wavelength of the laser light (pulse light) emitted from the YAG laser source 82 is 1064 nm. Therefore, when this laser light is applied to a nonlinear optical crystal 86 such as a KTP crystal shown in FIG. 9 at an appropriate incident angle, a half-length wavelength of 1064 nm can be obtained due to the nonlinear optical characteristics of the crystal. it can. Thus, G light having a wavelength of 532 nm can be produced.

FIG. 11 shows a specific example of the He / Ne laser source 81. In this case, the above-described Q switch is used. As shown in FIG. 11, the housing 110 is filled with a helium gas and a neon gas, and the inside of the mirror 110 is a total reflection mirror.
2 and a partially transmissive mirror 114 that can partially emit light of a specific wavelength are arranged so as to face each other. A Q switch 116 is provided on the front surface of the partial transmission mirror 114.
Is arranged. A switching signal of a predetermined frequency is given to the control terminal 117 from the oscillation circuit 118. Due to the resonance phenomenon between the partially transmitting mirror 112 and the Q switch 116, the specific wavelength, in this example, the wavelength of R resonates. Therefore, as shown in FIG.
18 is turned on and off, the R laser beam (wavelength is 633)
nm).

Since the light source 80 can use the laser light (B light) of the semiconductor laser itself, such an oscillating means is not necessary. As the blue semiconductor laser diode that generates the B wavelength, a laser diode made of GaN (gallium nitride) can be used.

As described above, the different light sources 80, 8
Although the target light can be obtained even when the light sources 1 and 82 are used, the output phase of the sine wave oscillator 104 is adjusted so that the output phase has a phase relationship as shown in FIG.

As the light source means 50, three light sources each composed of a YAG laser can be used. In this case, the switching signals for controlling the Q switches applied to the R, G, and B lasers are transmitted as shown in FIG. The light source means 50 having a waveform as shown in FIG.
Can be formed.

By the way, in order to obtain a halftone of the image displayed on the screen 54, the value of the excitation current may be adjusted as shown in FIG. In the case of a laser diode, the gradation can be digitally obtained. One such method is PWM (Pulse Width Modulation) modulation. PW
An example of the M modulation is shown in FIGS.

FIG. 12 shows an example in which one frame is divided into １ ／ and each is further divided into eight. Then, eight gradations can be realized (FIG. 12A). Figure 1 shows an example of gradation control
2B and 2C.

FIG. 13 shows another modulation example. This example is a modulation method in which one frame is divided into (gradation-1) × 3 and the modulation of the minimum unit time is repeated as R, G, B, R, G, B. 13B, 13C, and 13D show examples of gradation settings for the R, G, and B signals. R, G, B in a short time as shown in FIG.
When it is necessary to repeat the above, the output light having any of the waveforms shown in FIGS. 2A, 2B, and 2C can be applied.

[0071]

As described above, according to the present invention, a high-efficiency optical device is realized by using one spatial light modulator.

In the present invention, the use of a single spatial light modulator allows the device to be reduced in size, the number of internal optical elements to be reduced, the device to be lighter, and to be manufactured at a low cost.

In addition, by using the light source means using a plurality of independent light sources of R, G, and B, it is possible to realize an optical device for a color video projector device with high efficiency and high luminance. As a result, a reduction in power consumption, a reduction in the amount of heat generation, and the like can be achieved.

[Brief description of the drawings]

FIG. 1 is a system diagram of a main part when an embodiment of a light source device according to the present invention is applied to a color video projector device.

FIG. 2 is a diagram showing a waveform and a phase relationship of emitted light.

FIG. 3 is an explanatory diagram of a light modulation operation.

FIG. 4 is a system diagram showing one embodiment of a color video projector device to which the present invention is applied.

FIG. 5 is a diagram illustrating emission phases of R, G, and B light sources.

FIG. 6 is a perspective view of a light guide.

FIG. 7 is an explanatory diagram of photosynthesis.

FIG. 8 is a diagram showing another embodiment of the light source means.

FIG. 9 is a system diagram showing another embodiment of a color video projector device to which the present invention is applied.

FIG. 10 is a configuration diagram of a YAG laser source.

FIG. 11 is a configuration diagram of a He / Ne laser source.

FIG. 12 is an explanatory diagram of gradation control (part 1).

FIG. 13 is an explanatory diagram of gradation control (part 2).

FIG. 14 is a configuration diagram showing a conventional example of a three-plate type projector device.

FIG. 15 is a configuration diagram showing a conventional example of a single-panel type projector device.

FIG. 16 is a diagram illustrating a relationship between a color separation unit and a spatial light modulator (part 1).

FIG. 17 is a diagram illustrating a relationship between a color separation unit and a spatial light modulator (part 2).

[Explanation of symbols]

52: spatial light modulator, 54: screen, 5
0 ... light source means, 64R, 64G, 64B, 80, 8
1,82 ... light source

Claims (7)

[Claims] 1. A light source comprising: light source means for emitting light having a plurality of different wavelengths; one spatial light modulation element; and optical means for guiding light emitted from the light source to the spatial light modulation element. The means is composed of a plurality of light sources that emit light of different wavelengths independently of each other. From the light source means, light of different wavelengths of the emitted light is repeatedly emitted at a fixed period at different times. Characteristic optical device. 2. The spatial light modulation device according to claim 1, wherein a modulated video signal is supplied to the spatial light modulation device in synchronization with a wavelength of light emitted from the light source unit and incident on the spatial light modulation device. Optical device. 3. The optical device according to claim 1, wherein a light source constituting said light source means comprises a light emitting diode. 4. The optical device according to claim 1, wherein a light source constituting said light source means is a laser. 5. When a laser is used as one or more light sources constituting the light source means, the light source is provided with a Q switch for determining a resonance sharpness, and the emission phase is controlled by controlling the Q switch. 5. A pulsed laser beam is obtained.
The optical device according to any one of the preceding claims. 6. The optical device according to claim 1, wherein the spatial light modulator is a two-dimensional liquid crystal device. 7. An optical device according to claim 1, wherein light of three primary color signals is emitted from said light source means.