JPH11305710A - Method and device for modulating light and method and device for projecting image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently utilize the power of a light beam to modulate the light beam by synchronizing the incident timing of plural incident light beams having mutually independent peak wavelength values to an optical modulation element with the modulation timing of the optical modulation element to modulate these incident light beams. SOLUTION: After the optical axes of respective laser beams emitted from respective color pulse lasers of a red pulse laser 1, a green pulse laser 2 and a blue pulse laser 3, are aligned by using a dichroic prism 4, the respective beams are transmitted through an indegrator 5 as an element for unifying these optical axes in the plane and made incident upon a light bulb 6. A drive signal generation circuit 18 for supplying a drive signal to the light bulb 6 and respective color laser light sources 1 to 3 is provided and a synchronizing signal corresponding to a video signal is supplied to respective delay circuits 15 to 17 connected to respective light sources 1 to 3, to make oscillation timing synchronize with opening/closing timing timely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a light modulation method and a light modulation device, and an image projection method and an image projection device (for example, a liquid crystal projector).

[0002]

2. Description of the Related Art Conventionally, in an image projection apparatus (for example, a projection type liquid crystal projector), incoherent light such as a halogen lamp or a light emitting diode (LED) has been used as a light source.

[0003] However, these are incoherent light sources utilizing spontaneous emission and have large power consumption.
Problems remain such as low brightness. Therefore, research and development of an image projection apparatus that uses laser light capable of obtaining high-brightness and high-definition light with low power consumption as a light source for illumination have been performed.

[0004] In recent years, a display element using a digital gradation method has been proposed, and this is also used in an image projection apparatus. However, in order to obtain a full-color image by such a gradation method, an image corresponding to each color element must be generated by each light valve (LV) and projected. Therefore, the number of light valves corresponding to each of red (R), green (G), and blue (B) is required, which hinders cost reduction.

Therefore, a method is proposed in which one light valve (or a spatial light modulator, SLM: Spatial Light Modulator) is used, each color element is time-divided in the same pixel, and the corresponding image is switched at high speed and projected on a screen. Have been. In this case, the image on the screen and its color are switched at the same time, but since the pixel switching is performed at high speed, the human eye recognizes the image as a full-color image due to the integration effect. That is, if such a method is employed, the number of expensive light valves can be reduced.

[0006]

By the way, a light valve for displaying pixels corresponding to two or more colors in the same pixel and a light source capable of oscillating laser light corresponding to two or more colors are used. When modulating each color laser light by time division of each color in the bulb, even if the laser light source is a continuous wave light source (ie, a cw laser light source), while the light valve displays a specific color, another light source is used. Laser light from a laser source emitting color must be shielded in some way.

For example, when a continuous wave oscillation laser light source is used as a light source for each of the three primary colors of red, green, and blue, the time that can be used as actual illumination light is one third of each oscillation time. It is only. In other words, the power illuminated on the screen is less than one-third of the power required for the laser light source. As a result, a light source having at least three times the power actually required as the illumination light source is obtained. Is required for each color.

That is, when displaying images of many colors with the same pixel of one light valve, the display colors of the light valve are switched in a time-division manner, so that the power use efficiency of the laser light is inevitably reduced. Would. Also, while modulating one color, it is necessary to shield other colors from light.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a light modulation method and a light modulation device for modulating a light beam by efficiently using the power of the light beam. To provide.

[0010] Still another object of the present invention is to modulate a light beam by efficiently using the power of the light beam and project the modulated light beam onto a projection target to obtain a predetermined projection image. An object of the present invention is to provide a projection method and an image projection device.

[0011]

That is, according to the present invention, when a plurality of incident lights having mutually independent peak wavelengths are modulated by a light modulation element, each of the plurality of incident lights having mutually independent peak wavelengths is modulated. A method of providing a light modulation method for modulating the incident light by synchronizing the respective timings of incidence on the light modulation element with the modulation timing of the light modulation element (hereinafter referred to as the modulation method of the present invention). It is.

According to the modulation method of the present invention, a plurality of incident lights (light beams) having mutually independent peak wavelengths are transmitted to a light modulation element such as a liquid crystal light valve (particularly a spatial light modulation element).
At the time of modulating, the respective incident timings of the plurality of incident lights having the mutually independent peak wavelengths to the light modulation element and the modulation timing in the light modulation element are synchronized to modulate the incident light. In addition, while efficiently using the power of the light beam and modulating incident light having a specific peak wavelength, it is not necessary to block incident light having other peak wavelengths.

According to the present invention, as a device for performing the modulation method of the present invention with good reproducibility, a plurality of incident lights such as laser beams having independent peak wavelengths are modulated by a light modulation element such as a light valve. A light modulator for generating a synchronization signal for synchronizing each of the plurality of incident lights having the independent peak wavelengths to the light modulation element and the modulation timing in the light modulation element. It is an object of the present invention to provide a light modulator provided with a means (hereinafter, referred to as a modulator of the present invention).

According to the present invention, as a method for projecting an image using the modulation method of the present invention, a plurality of light beams having mutually independent peak wavelengths are modulated by a light modulating element, and the modulated light beam is projected onto the object. When projecting a predetermined image by projecting on the body, the respective incident timings of the plurality of light beams having mutually independent peak wavelengths to the light modulation element, and the modulation timing in the light modulation element are synchronized. An image projection method for modulating the light beam (hereinafter, referred to as an image projection method)
This is referred to as the image projection method of the present invention. ).

According to the image projection method of the present invention, a plurality of light beams having mutually independent peak wavelengths are modulated by the light modulating element, and the modulated light beams are projected onto a projection object such as a screen to thereby obtain a predetermined light beam. In projecting the image, each of the plurality of light beams having the independent peak wavelengths is incident on the light modulation element, and the light timing is modulated by synchronizing the modulation timing in the light modulation element. Therefore, it is not necessary to shield incident light having other peak wavelengths while efficiently using the power of the light beam and modulating the light beam having a specific peak wavelength. In other words, there is no need to consider the problem of heat waste generated during light shielding. Furthermore, if a laser beam is used as the light beam, a high-brightness, high-definition projected image can be obtained.

Further, according to the present invention, as an apparatus for implementing the image projection method of the present invention with good reproducibility, a plurality of light beams having mutually independent peak wavelengths are modulated by a light modulation element, and the modulated light beam is modulated. An image projection device that projects onto a projection target such as a screen and projects a predetermined image,
An image projection apparatus provided with a synchronizing signal generation unit for synchronizing each of the plurality of light beams having the independent peak wavelengths to the light modulation element with the respective incident timings of the plurality of light beams and the modulation timing in the light modulation element; (Hereinafter, referred to as an image projection device of the present invention).

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The modulation method of the present invention, the modulation apparatus of the present invention, the image projection method of the present invention, and the image projection apparatus of the present invention (hereinafter, may be collectively referred to as "the present invention") will be described in further detail. Will be described.

In the present invention, the oscillation period of laser light oscillated from a plurality of laser light sources having oscillation wavelengths independent of each other and the modulation period of an optical modulation element that performs modulation corresponding to the plurality of laser lights in a time-division manner. In synchronization with each other, the plurality of laser beams can be independently modulated.

In the present invention, it is desirable that the laser light source is a pulse laser light source, and that each of the laser lights is modulated by synchronizing the pulse oscillation cycle with the modulation cycle. That is, pulsed laser light oscillated from a plurality of pulsed laser light sources capable of pulse oscillation can be provided as the incident light (or light beam) having the plurality of peak wavelengths.

For example, the optical axis of each pulse laser beam oscillated from a plurality of pulse laser light sources is aligned using a dichroic mirror, an optical fiber, or the like, and guided to the light modulation element to perform modulation corresponding to each pulse laser beam. At this time, the pulse oscillation cycle of each pulse laser light source is shifted by a predetermined time from each other, and the oscillation cycle of each pulse laser beam is synchronized with the modulation cycle of the light modulation element, so that the modulation timing ( In particular, the pixel switching timing) coincides with the timing at which the pulsed laser light is incident on the light modulation element, so that the power utilization efficiency of the laser light source can be maximized. Furthermore, while modulating the laser light from a particular laser light source, there is no need to block the laser light from another laser light source. In other words, there is no need to consider the problem of heat waste generated during light shielding.

Further, by using a laser beam as the incident light (or light beam), it is possible to obtain high-brightness and high-definition illumination light with low power consumption. Further, since one light modulation element is used, each color element is time-divided in the same pixel, and the corresponding image is switched at high speed and projected on the screen, the number of expensive light modulation elements can be reduced (for example, In the case of an equal projection device, it can be constituted by only one light modulation element).

Further, in the present invention, two pixels are used for one pixel.
Synchronize the pixel switching period in a digital gradation display type light modulation element that displays images corresponding to more than two types of colors in a time division manner with the pulse oscillation period of laser light emitted from two or more types of pulsed laser light sources. It is desirable.

That is, the power of the light source can be used efficiently by using a pulse laser as the laser light source and synchronizing the pulse oscillation cycle with the pixel switching cycle of the light modulation element. In particular, when there are a plurality of light sources, the power of the plurality of light sources can be used efficiently by dividing the pixel switching period and synchronizing the color of the laser light with the display image of the light modulation element.

In the present invention, the oscillation timing of the laser light from each of the pulse laser light sources is independent of each of the pulse laser light sources so that the timing of opening and closing the pixels in the light modulation element does not deviate. It is desirable to provide a delay circuit.

As will be described in detail later, as shown in FIG.
A drive signal generating circuit 18 for supplying a drive signal (especially a synchronization signal) to the light modulation element (light valve) 6 and each color laser light source is provided, and a synchronization signal corresponding to a video signal is generated.
Delay circuit 1 connected to laser light sources 1, 2 and 3 of each color
The oscillation timing and the opening / closing timing can be synchronized with good timing by supplying them to 5, 16, and 17. Note that the delay circuits 15, 16, and 17 may also serve as drive circuits for the respective laser light sources. Further, an intensity signal for gradation display can be supplied from the drive circuit together with the synchronization signal.

In the present invention, the same pixel is divided into three parts in time, and the three parts are switched at each time to correspond to each color of red (R), green (G) and blue (B). Using a light modulation element of a digital gradation display system that creates an image to be reproduced, and using a pulsed laser light source that oscillates laser light corresponding to each of the colors, a cycle of one third of the pixel switching cycle of the light modulation element It is preferable to oscillate the pulsed laser beams by shifting them by an amount, and synchronize the pixel switching timing of the light modulation element with the oscillation cycle of the laser beams.

That is, when configuring an image projection device such as a projection type liquid crystal projector, a full-color projection image can be obtained by performing modulation of each of the three colors of RGB at least once in one field.

In the present invention, gradation in the digital gradation display can be performed by changing the pulse energy of the pulse laser light source. That is, as will be described later in detail, as shown in FIG. 4, gradation display (digital gradation display) can be performed by controlling the pulse energy corresponding to each color stepwise within one field. However, this gradation display may be performed by appropriately adjusting the pulse energy oscillated from the laser light source, or may be performed simultaneously with the modulation of the light modulation element.

Further, in the present invention, each laser light oscillated from each of the pulse laser light sources is introduced into a number (ie, two or more) of optical fibers corresponding to the number of these laser light sources, and these optical fibers are bundled. It is preferable that each of the laser beams is guided from the bundle portion to the light modulation element. In particular, by using this optical fiber (or bundle fiber) as a multi-mode plastic fiber (or multi-mode plastic fiber bundle), laser light can be favorably guided and speckles generated due to high coherence can be reduced. Is achieved.

Next, preferred embodiments according to the present invention will be described.

Here, a full-color image projection using three primary colors of red (R), green (G) and blue (B) will be described. However, the present invention is not limited to three colors, and is also effective for a color projection image using two or more colors.

First, as shown in FIG. 2, in this image projection apparatus, if the time interval for displaying each image of each color by the light valve is represented by t _sub , one image field (1
The time interval corresponding to (frame) is t _field = 3t _sub .

As a laser light source capable of pulse oscillation, for example, in the case of a pulse laser light source of green oscillation, the following configuration is conceivable.

That is, as is well known, a plurality of mirrors,
A laser active medium such as a Nd: YAG crystal, a semiconductor laser for exciting a laser light active medium, a KNbO ₃ crystal for wavelength conversion, for example, and an acousto-optic device (AOM: Acousto Optic Modulator) as a Q switch. With this laser, green laser light having a wavelength of 532 nm can be pulse-oscillated by wavelength conversion in a resonator.

However, the laser light source that can be used in the present invention is not limited to the pulse oscillation laser light source having the above configuration. For example, as a crystal for wavelength conversion (particularly, generation of the second harmonic), LBO ( Lithium borate), B
BO (β-barium borate: β-BaB ₂ O ₄ ), KT
P (potassium phosphotitanate: KTiOPO ₄ ) or the like can be used, and an electro-optical element can be applied to the Q switch or the like. In addition, for a laser of blue, red, or the like, a pulse oscillation laser light source having a similar configuration can be manufactured by selecting another known laser medium crystal, wavelength conversion crystal, or the like.

FIG. 1 shows the configuration of an image projection apparatus including such a pulse laser.

That is, when projecting the image displayed on the light valve 6 onto the screen 8, the optical axis of each laser beam emitted from the pulse laser of each color of the red pulse laser 1, the green pulse laser 2 and the blue pulse laser 3 Are combined using a dichroic prism 4 and then an integrator 5 as an element for uniformizing the amount of light in the plane
Is transmitted through the light valve 6 and is incident (irradiated) on the light valve 6, and an image to be projected is further projected on a screen 8 via a projection lens 7.

When the light valve 6 for displaying each color (three primary colors) operates at the frequency f (Hz), the time interval for displaying three colors is t _field = 1 / f second (see FIG. 2). ). In addition, the time t _open during which the light valve 6 is open for displaying the image of each color has to be considered non-emission time for driving the pixels in the light valve 6, so that t _open <(t _field / 3).

Therefore, _assuming that the spontaneous emission lifetime of the crystal as the laser active medium is t _spon and the repetition period of the pulse laser is t _interval , the energy of one pulse is approximately

(Equation 1) Becomes Here, P _cw indicates the average power when the laser is continuously oscillated.

The pulse intervals of the laser light sources 1, 2 and 3 are set so that t _interval = t _{field in} order to synchronize the opening and closing timing of the pixels in the light valve 6.

As shown in FIG. 3, the timing of the pulse oscillated from each laser light source is determined by the provision of delay circuits 15, 16 and 17 in each of the laser light sources 1, 2 and 3 for opening and closing the light valve 6. Drive signal generation circuit (synchronous signal generation circuit) so as not to deviate from the timing
The synchronization signal corresponding to the video signal from the delay circuit 1
5, 16 and 17 and the light valve 6, respectively. The delay circuit also serves as a drive circuit for the laser light source of each color, and is configured such that the intensity of the oscillated pulse can be adjusted by this circuit.

Here, the pulse width of each color laser light source varies depending on the design of the resonator or the like, but the time width is about several tens ns, and the pixel switching time interval of the light valve 6 (that is, the pixel opening / closing time). (Interval), which is sufficiently shorter than several tens of μs. That is, the amount of light energy radiated during the time _{tinterval in} the case of the continuous wave light source can be emitted within several tens of ns when the light valve is open by using the pulse laser light source as in the present embodiment.

In the case of a continuous wave light source, while a certain color is being projected, other colors are blocked, so that the power of that portion cannot be used. In other words, considering such power loss, the energy that can be emitted by the pulsed laser when the light valve is opened is smaller than when a continuous wave light source is used.

(Equation 2) Double.

Next, a specific example of the opening / closing timing of the light valve when a pulse laser using the above-described Nd: YAG crystal is used will be described with reference to FIG.

[0045] That is, when 150μs close timing period t _sub light valve, since using three colors for full-color image reproduction, 3 Iroichi field period t _field screen, the t _field = 450μs. Therefore, 1
The pulse period per color is _defined as t _interval = t _field (= 45
0 μs).

[0046] However, the opening time t _open of the pixels in the light valve is only t _open = 100 [mu] s approximately Considering non-emission time (e.g. 50 [mu] s) for that pixel control. Since the open time of the pixel in the light valve is short as described above, when a continuous wave laser is used as a light source, only about 22% (= t _open / t _field ) of the light source power can be used.

On the other hand, when a pulse laser is used as the light source as in this embodiment, the spontaneous emission lifetime _tspon of the Nd: YAG crystal is _tspon = 230 μs, so that the mirror design of the resonator is appropriately selected. Then, the pulse width becomes several tens ns. Therefore, the entire energy of the pulse oscillated from the laser light source can be emitted during the opening time t _open of the pixel in the light valve.

As described above, when the pulse laser is used, compared with the case where the continuous wave laser is used,

(Equation 3) = 3.9 times the efficiency is realized, and the power utilization efficiency of the light source, that is, the utilization efficiency of the laser light is greatly improved.

While the laser light of a specific color is being modulated in the light valve, the laser light of other colors is not oscillated. Also, the supply of energy required to operate this can be omitted. Furthermore, there is no need to consider the problem of heat disposal caused by shading.

In the wavelength conversion method using a nonlinear optical crystal as described above, a higher wavelength conversion efficiency can be obtained with a laser beam having a high peak power such as a pulse wave. For this reason, the use of the pulsed laser light source can provide a greater wavelength conversion efficiency, and the use of the pulsed laser light source has an advantage that a larger visible light power can be applied.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the above-described embodiments.

For example, as shown in FIG. 4, by controlling the peak power of the pulse laser stepwise, it is possible to give a gradation difference to the brightness of the projected image to be irradiated. Therefore, digital gradation display of display pixels can be performed, and gradation can be given to brightness by controlling the pulse peak intensity for each subfield time t _subfield .

By illuminating three primary colors in one subfield and performing gradation display for each color, a one-field image can be displayed in gradation. Furthermore, by synchronizing the pulse interval of the laser light source with t _subfield , that is, for example, by providing a delay circuit for synchronizing the oscillation timing of the pulse laser with t _subfield independently for each color laser light source, pulse generation by modulation of pulse energy Deviation due to a change in rise time can be prevented.

Also, as shown in FIG. 5, each color laser light emitted from each color laser light source 1, 2 and 3 is converted into an optical fiber (or fiber bundle: bundle) without using the dichroic prism 4 and the integrator 5 in FIG. Fibers 11, 12, and 13, and the light emitted from the fiber bundle obtained by bundling them can be applied to the light valve 6 via the lens 9.

Further, in the present embodiment, a light transmissive liquid crystal light valve is used as a light modulating element (spatial light modulating element), that is, a light valve. Good. Further, a spatial light modulator using a micromirror (DMD: digital micromirror device) can be used.

Further, the modulation method and the modulation apparatus of the present invention are not limited to display applications such as an image projection apparatus, and a large-capacity and high-speed spatial real-time signal processing in optical computing and optical information processing technology. Can be used for

[0057]

According to the modulation method of the present invention, when a plurality of incident lights having mutually independent peak wavelengths are modulated by the light modulation element, each of the plurality of incident lights having the mutually independent peak wavelengths is modulated. Since each incident timing to the light modulation element and the modulation timing in the light modulation element are synchronized to modulate the incident light, the power of the light beam is efficiently used, and the incident light having a specific peak wavelength is used. While modulating light, it is not necessary to block incident light having other peak wavelengths.

According to the modulator of the present invention, there is provided a light modulator for modulating a plurality of incident lights having mutually independent peak wavelengths with a light modulating element, wherein the plurality of incident lights having mutually independent peak wavelengths are modulated. Since there is provided a synchronization signal generating means for synchronizing each incident timing of each light to the light modulation element and the modulation timing in the light modulation element, it is possible to implement the modulation method of the present invention with good reproducibility. Can be.

According to the image projection method of the present invention, a plurality of light beams having mutually independent peak wavelengths are modulated by the light modulation element, and the modulated light beams are projected on the object to project an image. At this time, each of the plurality of light beams having independent peak wavelengths is incident on the light modulation element, and the light beam is modulated by synchronizing the modulation timing in the light modulation element. While efficiently utilizing power and while modulating a light beam having a specific peak wavelength, there is no need to block light beams having other peak wavelengths, and in particular, laser light is used as the light beam. if,
High-brightness, high-definition image projection can be performed.

According to the image projection apparatus of the present invention, a plurality of light beams having mutually independent peak wavelengths are modulated by the light modulation element, and the modulated light beams are projected on the object to project an image. An image projection apparatus, wherein a synchronization signal generation unit for synchronizing each of the plurality of light beams having independent peak wavelengths to the light modulation element and the modulation timing in the light modulation element is provided. Since it is provided, the image projection method of the present invention can be performed with good reproducibility.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image projection device according to an embodiment of the present invention.

FIG. 2 is a time chart when a multi-color image is projected with the same time-division pixel in the image projection apparatus.

FIG. 3 is a schematic configuration diagram including a drive circuit of the image projection apparatus.

FIG. 4 is a time chart when a gradation display method based on luminance modulation is used in the image projection apparatus.

FIG. 5 is another schematic configuration diagram of the image projection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Red (R) pulse laser, 2 ... Green (G) pulse laser, 3 ... Blue (B) pulse laser, 4 ... Dichroic prism, 5 ... Integrator, 6 ... Light valve (spatial light modulation element), 7 ... Projection Lens, 8 ... Screen, 9 ... Lens, 11, 12, 13 ...
Optical fiber (or bundle fiber), 15, 1
6, 17: delay circuit (driver circuit), 18: drive signal generation circuit (synchronous signal generation circuit)

Claims (32)

[Claims] When a plurality of incident lights having independent peak wavelengths are mutually modulated by an optical modulation element, each of the plurality of incident lights having the independent peak wavelengths is incident on the light modulation element. And modulating the incident light by synchronizing the modulation timing with the light modulation element. 2. An oscillation cycle of laser light oscillated from a plurality of laser light sources having oscillation wavelengths independent of each other;
2. The light modulation method according to claim 1, wherein the plurality of laser beams are independently modulated by synchronizing a modulation period of an optical modulation element that performs modulation corresponding to the plurality of laser beams in a time-division manner. 3. The light modulation method according to claim 2, wherein the laser light source is a pulsed laser light source, and the laser light is modulated by synchronizing the pulse oscillation cycle with the modulation cycle. 4. A pixel switching cycle in a light modulation element of a digital gradation display system in which one pixel displays images corresponding to two or more colors in a time-division manner, and is oscillated from two or more pulse laser light sources. The light modulation method according to claim 1, wherein the pulse oscillation cycle of the laser light is synchronized. 5. An independent delay circuit is provided for each of the pulse laser light sources so that the oscillation timing of the laser light from each of the pulse laser light sources does not deviate from the opening / closing timing of a pixel in the light modulation element. The light modulation method according to claim 4. 6. A light modulation element of a digital gradation display system, which divides the same pixel into three parts in time and switches between the three parts in time to create images corresponding to red, green and blue colors. A pulse laser light source that oscillates a laser beam corresponding to each of the colors, oscillates a laser beam at a cycle of one-third of the pixel switching cycle of the light modulation element, and sets a pixel switching timing of the light modulation element. Synchronizing the oscillation cycle of the laser light,
The light modulation method according to claim 4. 7. The light modulation method according to claim 4, wherein a gradation in the digital gradation display is performed by changing a pulse energy of the pulse laser light source. 8. Each laser light oscillated from each of the pulse laser light sources is introduced into two or more optical fibers corresponding to these laser lights, and each of the laser lights is emitted from a bundle unit that bundles these optical fibers. The light modulation method according to claim 4, wherein the light is guided to a modulation element. 9. A light modulator for modulating a plurality of incident lights having mutually independent peak wavelengths with a light modulating element, wherein the light modulating elements each for the plurality of incident lights having mutually independent peak wavelengths. A light modulation device, comprising: a synchronizing signal generation unit for synchronizing each incident timing of the light with the modulation timing in the light modulation element. 10. The oscillation cycle of laser light oscillated from a plurality of laser light sources having oscillation wavelengths independent of each other and the modulation cycle of an optical modulation element that performs modulation corresponding to the plurality of laser lights in a time division manner. And wherein the plurality of laser beams are independently modulated.
2. A light modulation device according to claim 1. 11. The light modulation device according to claim 10, wherein the laser light source is a pulse laser light source, and the pulse oscillation cycle and the modulation cycle are synchronized, and the laser beams are modulated. 12. A pixel switching cycle in a digital gradation display type light modulation element for displaying an image corresponding to two or more types of colors in one pixel in a time-division manner, and oscillating from two or more types of pulsed laser light sources. The light modulation device according to claim 9, wherein a pulse oscillation cycle of the laser light is synchronized. 13. An independent delay circuit is provided for each of the pulse laser light sources so that the oscillation timing of the laser light from each of the pulse laser light sources does not deviate from the opening / closing timing of a pixel in the light modulation element. 13. The light modulation device according to claim 12, wherein: 14. The same pixel is temporally divided into three,
By switching this every time, red, green and light modulation elements of a digital gradation display system that creates an image corresponding to each color of blue are used, from a pulsed laser light source that oscillates the laser light corresponding to each color, The laser light is oscillated at a cycle of one third of the pixel switching cycle of the light modulation element, and a pixel switching timing of the light modulation element and an oscillation cycle of the laser light are synchronized. Light modulator as described. 15. The light modulation device according to claim 12, wherein a gradation in the digital gradation display is performed by changing a pulse energy of the pulse laser light source. 16. The laser light emitted from each of the pulsed laser light sources is introduced into two or more optical fibers corresponding to the laser light, and the laser light is emitted from a bundle unit that bundles these optical fibers. 13. The light modulation device according to claim 12, which is guided to a modulation element. 17. A method for modulating a plurality of light beams having mutually independent peak wavelengths with a light modulation element and projecting the modulated light beam onto a projection target to project an image, wherein the mutually independent peak wavelengths are used. An image projection method, wherein the incident light is modulated by synchronizing the respective timings at which each of the plurality of light beams is incident on the light modulation element with the modulation timing at the light modulation element. 18. An oscillation cycle of laser light oscillated from a plurality of laser light sources having oscillation wavelengths independent of each other and a modulation cycle of an optical modulation element which performs modulation corresponding to the plurality of laser lights in a time division manner. And modulating the plurality of laser beams independently of each other.
7. The image projection method according to 7. 19. The image projection method according to claim 18, wherein the laser light source is a pulse laser light source, and the laser light is modulated by synchronizing the pulse oscillation cycle with the modulation cycle. 20. A pixel switching cycle in a digital gradation display type light modulation element for displaying an image corresponding to two or more colors in one pixel in a time-division manner, and oscillating from two or more pulse laser light sources. The image projection method according to claim 17, wherein the pulse oscillation cycle of the laser light is synchronized. 21. An independent delay circuit is provided for each of the pulse laser light sources so that the oscillation timing of the laser light from each of the pulse laser light sources does not deviate from the opening / closing timing of a pixel in the light modulation element.
The image projection method according to claim 20. 22. The same pixel is temporally divided into three,
By using a light modulation element of a digital gradation display system that creates an image corresponding to each color of red, green and blue by switching this every time, from a pulse laser light source that oscillates laser light corresponding to each color, 21. The method according to claim 20, wherein the laser light is oscillated at a cycle that is one third of the pixel switching cycle of the light modulation element, and the pixel switching timing of the light modulation element is synchronized with the oscillation cycle of the laser light. Image projection method. 23. The image projection method according to claim 20, wherein a gradation in the digital gradation display is performed by changing a pulse energy of the pulse laser light source. 24. Each laser light oscillated from each of the pulsed laser light sources is introduced into two or more optical fibers corresponding to these laser lights, and the respective laser lights are emitted from a bundle unit where these optical fibers are bundled. 21. The image projection method according to claim 20, wherein the image is guided to a modulation element. 25. An image projection apparatus for modulating a plurality of light beams having mutually independent peak wavelengths with a light modulation element, and projecting the modulated light beams onto a projection target to project an image. An image projection apparatus, comprising: a synchronization signal generating unit configured to synchronize each of the timings at which the plurality of light beams having the peak wavelengths independent of each other enter the light modulation element and the modulation timing of the light modulation element. . 26. The oscillation cycle of laser light oscillated from a plurality of laser light sources having oscillation wavelengths independent of each other and the modulation cycle of an optical modulation element that performs modulation corresponding to the plurality of laser lights in a time division manner. And wherein the plurality of laser beams are independently modulated.
5. The image projection device according to 5. 27. The image projection apparatus according to claim 26, wherein the laser light source is a pulse laser light source, and the pulse oscillation cycle and the modulation cycle are synchronized, and the laser beams are modulated. 28. A pixel switching period in a digital gradation display type light modulation element for displaying images corresponding to two or more colors in one pixel in a time-division manner, and oscillation from two or more pulse laser light sources. 26. The image projection device according to claim 25, wherein a pulse oscillation cycle of the laser light is synchronized. 29. An independent delay circuit is provided for each of the pulse laser light sources so that the oscillation timing of the laser light from each of the pulse laser light sources does not deviate from the opening / closing timing of a pixel in the light modulation element. An image projection apparatus according to claim 28. 30. The same pixel is temporally divided into three,
By switching this every time, red, green and light modulation elements of a digital gradation display system that creates an image corresponding to each color of blue are used, from a pulsed laser light source that oscillates the laser light corresponding to each color, 29. The laser light according to claim 28, wherein the laser light is oscillated at a cycle that is one third of the pixel switching cycle of the light modulation element, and the pixel switching timing of the light modulation element is synchronized with the oscillation cycle of the laser light. An image projection device as described. 31. The image projection device according to claim 28, wherein a gradation in the digital gradation display is performed by changing a pulse energy of the pulse laser light source. 32. Each laser light oscillated from each of the pulsed laser light sources is introduced into two or more optical fibers corresponding to these laser lights, and the respective laser lights are emitted from a bundle unit that bundles these optical fibers. 29. The image projection device according to claim 28, wherein the image projection device is guided to a modulation element.