JP2000194066A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device having a large reproducible color area and capable of displaying a more natural clearer color image. SOLUTION: As for the projection type display device 1, by a signal modulated by a control part based on image data equipped with data on the 4th color in addition to the data on three primary colors RGB inputted to an image input part, light is emitted by main laser oscillators 13R, 13G1 and 13B and an auxiliary laser oscillator 13G2, and a screen 50 is scanned with a laser beam LB through polygon mirrors 17 and 18, the laser beam LB is projected so as to display the image. In this case, by emitting the auxiliary laser beam LB(G2) of 500 nm in addition to the conventional three-primary-color RGB laser beams LB(M), if necessarily, a color which is not developed in the conventional three primary colors RGB is developed, then, a color image more faithful to a natural color is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display apparatus which projects a laser beam and scans the laser beam to display it on a screen, and more particularly to a projection display apparatus having an auxiliary laser oscillator.

[0002]

2. Description of the Related Art Conventionally, in a color image display device,
Various methods have been proposed to faithfully reproduce the color. Here, the color existing as visible light is a so-called color as represented in the CIE1931 chromaticity diagram of the XYZ color system (2 ° field of view) of the CIE (International Commission on Illumination) based on JISZ8701 shown in FIG. As shown in FIG. 4, the range of the spectrum locus that has a horseshoe shape can be reproduced in the case of additive color mixture using three primary colors.
The colors are in the range inside the triangle with the vertices representing the positions of the primary colors on the figure. As a color image display method,
For example, there is a color display using a CRT (cathode ray tube) or an LCD (liquid crystal display).
TSC (National Television S)
high-definition television, PDP (plasma display), LE
Although there is a color display using D (light emitting diode), color reproducibility has been improved in recent years.

Further, as described in JP-A-1-245780, JP-A-3-65916, and JP-A-4-181289, three primary colors of additive color mixing, red (hereinafter R) and green ( Hereinafter, G) and blue (hereinafter B) laser lights are oscillated, and the optical paths of the laser lights output from these laser oscillators are combined into one to perform simultaneous additive color mixing, and the combined laser lights are put on a screen. There has been proposed a projection display apparatus that projects a color image and two-dimensionally scans the image to display a color image or the like on a screen. In such a projection display device, a laser oscillator capable of emitting a wide range of colors in a frequency band close to a single wavelength by a semiconductor laser or the like is used for three primary colors of additive color mixture.
It has become possible to display a color with a wide color reproduction and no turbidity.

[0004]

However, the range of color reproduction is limited to the inside of a triangle having the vertices of the three primary colors as shown in the figure. Even if the position of this triangle is enlarged and moved,
In the horseshoe-shaped range described above, there is a problem that a portion that cannot be covered by the triangle is formed, that is, a large amount of colors that cannot be reproduced remain, and it is difficult to reproduce natural colors.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a projection display device capable of displaying a more natural and beautiful color image with a wide range of reproducible colors.

[0006]

According to a first aspect of the present invention, there is provided a projection display apparatus according to the first aspect, wherein three types of main laser beams having wavelengths of three primary colors of additive color mixture are used based on an image signal. A laser oscillator that oscillates auxiliary laser light having a wavelength different from the wavelengths of the three primary colors, and a laser beam of each wavelength oscillated from the laser oscillator, and integrally scans the desired image on a predetermined screen. And a laser scanner for projecting light.

[0007] In the projection display device of the invention according to this configuration,
By using light of the color of the auxiliary laser light, it is possible to reproduce colors that cannot be reproduced with light of the wavelengths of the three primary colors,
Color reproduction closer to a natural color can be performed.

[0008] In the projection display device according to the second aspect of the present invention,
In addition to the configuration of the projection display device according to the first aspect, the auxiliary laser light is oscillated only when at least one type of main laser light among the main laser lights is not oscillated.

[0009] In the projection display apparatus of the invention according to this configuration,
Control to oscillate the auxiliary laser light only when necessary can be performed.

[0010] In the projection display device according to the third aspect of the present invention,
In addition to the configuration of the projection display device according to claim 1 or 2, the auxiliary laser beam is set to approximately 500 nm.

[0011] In the projection display device of the invention according to this configuration,
A color near 500 nm, which could not be obtained with the conventional three primary colors, can be reproduced.

According to the projection display apparatus of the invention according to claim 4,
In addition to the configuration of the projection display device according to any one of claims 1 to 3, the image signal corresponds to an image signal corresponding to the wavelength of the three primary colors and a wavelength different from the wavelength of the three primary colors. And an image signal.

[0013] In the projection display device of the invention according to this configuration,
In a projection display device including a laser oscillator that oscillates auxiliary laser light, suitable control can be performed using this image signal, and color reproducibility can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a projection display device according to the present invention will be described by way of a preferred embodiment with reference to the accompanying drawings. Here, FIG. 1 is a schematic diagram illustrating a main configuration of a projection display device 1 according to an embodiment of the present invention.
First, the outline of the configuration of the projection display device 1 will be described with reference to FIG.

As shown in FIG. 1, the projection display device 1 includes a laser scanner unit 10, a control unit 40,
The image input unit 47 includes a screen 50 on which a laser beam LB is projected from the main body 2 to display an image.

The projection display device 1 has an interface 48
Based on image data input to the image input unit 47 via the
Then, a signal is sent from the control unit 40 to the scanner control unit 12.
Driven by the laser oscillator control unit 15 of the scanner control unit 12.
A motion signal is generated and provided in the laser scanner unit 10.
Red laser oscillator 13R, green laser oscillator 13G₁,
Blue laser oscillator 13B (see FIG. 3;
13M) and auxiliary laser oscillation
13G₂(These are collectively referred to as a laser oscillator 13.)
Are oscillated and the red laser beam LB (R) and the green laser beam
The beam LB (G ₁), Blue laser beam LB (B)
(Hereinafter, these are collectively referred to as a main laser beam LB (M).
U. ) And the auxiliary laser beam LB (G₂)
This is called a laser beam LB. ) Is emitted and irradiated,
The laser beam LB is applied to a main scanning polygon mirror (rotating
Mirror 17) and a sub-scanning polygon mirror 18 (hereinafter collectively referred to as
They are called polygon mirrors 17 and 18. ) In two dimensions
An image is formed by projecting the screen 50 while being scanned
Is what you do.

The control unit 40 includes a CPU (not shown) and a RAM (not shown).
And a well-known computer having a ROM. A program for controlling the entire projection display device 1 is stored in the ROM.
U performs input processing and data expansion, modulates the light emission of the laser oscillator 13 of the laser scanner unit 10 based on the image data, and projects while synchronizing with the polygon mirrors 17 and 18 based on the image data.
Is two-dimensionally scanned to display an image on the screen 50.

The screen 50 receives the laser beam LB and diffuses and transmits the laser beam LB so that an image can be observed by a user. The screen 50 is formed of a translucent milky white diffusing plate. In the present embodiment, the screen 50 and the main body 2 are configured as an open type that can be separated and movable, but they are integrated into a closed type in which the laser beam LB is not directly visible to the user. It may be configured. Further, the screen 50 may be such that the screen 50 is projected on a large screen constituted by a reflection diffusion plate. In short, the screen 50 can be of any type as long as the screen can be projected by the laser scanner unit 10 provided in the main body 2 and an image can be displayed.

FIG. 2 is a schematic diagram for explaining the laser scanner unit 10. As shown in FIG. Hereinafter, the structure and operation of the laser scanner unit 10 will be described with reference to FIG. First, the laser oscillator 13 includes a laser oscillator that oscillates a specific color.
A Kr laser is used for the red laser oscillator 13R that emits red light of 00 nm, and a He-Cd laser is used for the blue laser oscillator 13B that emits blue light of 450 nm.
The auxiliary laser oscillator 13G ₂ that emits bright green light of the green laser oscillator 13G ₁ and 500nm for emitting green light of nm, Ar laser is preferably used.

The laser beams LB (R), LB (G ₁ ) emitted from these four laser oscillators 13,
LB (B) and LB (G ₂ ) have one optical path by a first laser beam combiner 14A, a second laser beam combiner 14B, and a third laser beam combiner 14C (hereinafter referred to as laser beam combiner 14). It is combined with the laser beam LB.

Firstly red laser oscillator 13R and the green laser oscillator 13G ₁ is synthesized by the first laser beam combiner 14A. The first laser beam combiner 14A is composed of a dichroic mirror (wavelength selective reflector) coated with a specific wavelength transmitting and reflecting other wavelengths, and the laser beam emitted from the red laser oscillator 13R. LB (R) is to be transmitted, the green laser beam LB (G emitted from the green laser oscillator 13G _1
1 ) is made of a material that reflects light depending on the wavelength of output light. Therefore, the first laser beam combiner 14A
Orthogonally disposed a red laser oscillator 13R and the green laser oscillator is emitted from each of 13G ₁ red laser beam LB (R) and the green laser beam LB _{(G 1)} is
The red laser beam LB (R) passes through the dichroic mirror and travels straight, while the green laser beam LB (G ₁ ) is reflected by the dichroic mirror and its optical axis is deflected at right angles. And adjusted to have the same optical axis.

Similarly, a red laser beam LB (R) and a green laser beam LB (G ₁ ) are synthesized by a second laser beam synthesizer 14B and further a blue laser beam emitted by a blue laser oscillator 13B. LB
(B) is synthesized, and the main laser beam LB (M) is synthesized.

In addition to the main laser beam LB (M) thus generated, the third laser beam combiner 14C further converts the main laser beam LB (M) into an auxiliary laser beam LB (G ₂ ). The screen is scanned by the combined laser beam LB.

The synthesis of the laser beams LB of these three colors may be a dichroic prism or a configuration in which the luminous flux is synthesized by a prism using a difference in the refractive index depending on the wavelength. It suffices if the three light beams are combined into one light path.

Next, the laser beam LB of the projection display device 1
Will be described with reference to FIGS. 1 and 2. FIG. The laser beam LB emitted by the laser oscillator 13 and combined into one light beam by the laser beam combiner 14 contacts the main scanning polygon mirror 17 rotating at high speed. The main scanning polygon mirror 17 has a regular hexagonal prism shape having a height lower than the bottom surface as shown in FIG. 2, and is disposed at a position where a rotation axis is horizontal and a line perpendicular to the laser beam LB is translated upward. The laser beam L
B is reflected downward by the six plane mirrors rotating about the rotation axis, and the direction of the optical axis is set such that the rotation of the main scanning polygon mirror 17 increases the internal angle of the laser beam LB with the optical axis before reflection. Changes to

At this time, the laser beam LB reflected by the main scanning polygon mirror 17 is not projected outside the range of the predetermined angle, so that the laser oscillator control unit 15 and the polygon mirror control unit provided in the scanner control unit 12 are provided. 16. Further, in order to harmonize the control by the laser oscillator control unit 15 and the polygon mirror control unit 16, the optical axis of the laser beam LB reflected by the main scanning polygon mirror 17 is changed to the light beam of the laser beam LB at the main scanning start position. The main scanning beam sensor 19 is located near the passing position.
Is provided, the actual position of the laser beam LB is detected, and the light emission timing of the laser oscillator 13 is adjusted to the rotation of the main scanning polygon mirror 17. Here, the light received by the main scanning beam sensor 19 is sent to the control unit 40 as a signal, and this signal is hereinafter referred to as a main scanning SOS (Start).
This signal is referred to as “Of Scanning” signal. This main scanning SO
Upon detecting the S signal, the control unit 40 sets the laser oscillator control unit 1 based on the scanning start position calculated based on this signal.
5, a signal for laser emission modulated based on the image data is transmitted. In this manner, a signal modulated by one column of data is sent to a laser oscillator 13 by a laser oscillator control unit 15 which is a driving unit (driver) of the laser oscillator, and a laser beam LB is transmitted to a sub-scanning polygon mirror 18. And is scanned in the X direction of FIG. 2 on the screen 50, and an image for one line is projected on the screen.

On the other hand, the laser beam LB reflected and deflected by the main scanning polygon mirror 17 is reflected toward the sub-scanning polygon mirror 18 located therebelow in FIG. The sub-scanning polygon mirror 18 has a shape of an elongated hexagonal prism having six plane mirrors and a height higher than the bottom surface, and its rotation axis is horizontal, parallel to the screen 50, and is screened by the main scanning polygon mirror 17. The plane mirror is arranged at a position slightly displaced in the opposite direction to 50, and the longitudinal direction of the plane mirror is arranged in the same direction as the direction deflected by the main scanning polygon mirror 17. Then, the sub-scanning polygon mirror 18 rotates in a direction in which the upper end approaches the screen 50. Therefore, the laser beam LB reflected from the main scanning polygon mirror 17 is further deflected in the direction of the screen 50 so that the inner angle to be deflected increases with time, that is, in the Y direction of the screen 50. The direction of movement changes.

As described above, the sub-scan is performed in the vertical direction while performing the horizontal main scan. This is a scan similar to the horizontal scan and the vertical scan of a conventional well-known CRT. When horizontal scanning is repeatedly performed from the upper end to the lower end in this manner, one screen is displayed. However, since the sub-scanning polygon mirror 18 rotates at a constant speed, the control unit 40 sends a signal at an appropriate interval. . Then, the sub-scanning of the next screen can be performed on the next mirror surface of the rotating sub-scanning polygon mirror 18. This sub-scanning can be performed by using a galvanometer (oscillating single-sided mirror) that controls the tilt by the current. However, using a polygon mirror has less change in angular velocity than using a galvanometer. In particular, it is preferable to use a polygon mirror.

Strictly speaking, the sub-scanning polygon mirror 18 rotates while the main scanning polygon mirror 17 scans one main scanning line. Scanning polygon mirror 18
Are set in such a manner that the main scanning direction is slightly lowered.

Further, in order to detect the vertical scanning start position, the laser oscillator 13 is turned on slightly above the original scanning start position on the screen 50, and the laser beam LB is emitted without modulation and the main scanning is performed. And sub-scanning. Then, when the laser beam LB is incident on the sub-scanning beam sensor 20 arranged near the scanning start position, a sub-scanning SOS signal is sent from the sub-scanning beam sensor 20 to the control unit 40. The actual scanning start position is calculated, and after the calculated predetermined time, the laser scanner unit 1
A control signal is sent to the scanner control unit 12, and the scanner control unit 12 sends a drive signal to the laser oscillator 13 to modulate the light amount, and the main scanning and the sub-scanning are started.

As described above, the image displayed on the screen 50 by the laser beam LB shows pincushion-like distortion on both sides, and a gap between the scanning lines in the vertical direction occurs. Therefore, in the control unit 40, it is preferable to control the distortion correction by extending the modulation time for scanning the central part or shortening the modulation time at the upper end and the lower end. It is desirable to optically correct the distortion using a method such as the above.

In this embodiment, the scanning of 525 main scanning lines (horizontal scanning lines) for one screen is reduced to 1/3 in this embodiment.
The sub-scanning (vertical scanning) of 0 seconds is performed, and a smooth screen with little flicker can be projected.

Returning to FIG. 1, the description will be continued. As described above, the scanner controller 12 includes the laser oscillator controller 15 and
And a polygon mirror controller 16. The laser oscillator control unit 15 uses the weak signal transmitted from the control unit 40 as a drive signal as the drive signal of the laser oscillator 13 (see FIG. 2).
Driver to send to The polygon mirror control unit 16 also receives a weak signal from the control unit 40, and receives a main scanning polygon mirror 17 and a sub-scanning polygon mirror 18.
Is a driver that sends out a drive signal for driving a motor that rotates.

The image input section 47 is a buffer for externally inputting and storing image data to be projected, and is also a place for separating the image data into respective control signals.
It has storage means. As input data, a video signal is input via the interface 48. Of course, the data of the image information is not limited to the video signal, and it is sufficient if the image information can be read by some method. In the projection display device 1 according to the present embodiment, an input signal is obtained by adding an auxiliary signal to an RGB video signal, using image signals of video signals of four colors, and generating an image based on these signals.

Here, the image signal will be described.
First, the color perceived by the human eye will be described. The color perceived by the human eye is a stimulus received by three types of cones of the retina.
It is governed by the stimulus value. And Grassman (Gra
As is known by the law of sssmann), all color lights can be made equal by a mixture of three independent color lights (metamerism, Metamerism)
It has been known. "Metamerism" refers to the inability of a person to distinguish between two types of light with different spectral compositions that produce equal tristimulus values under the same circumstances. The term "independent three colors" means that one of the two colors cannot be equalized with the other two colors.

However, this is not an accurate expression, and will be further described as follows. For example, C
Red (R) primary color light is λ = 700n as in the IE standard.
m, the primary color of green (G) is monochromatic light of λ = 546.1 nm, and the primary color of blue (B) is monochromatic light of λ = 435.8 nm. Then, a color matching experiment is performed using these three colors. Here, the "color matching experiment" means that RGB three color light sources are prepared, the energy intensity of each light source is adjusted to make a mixture, and the mixed light is arbitrarily colored, and the three primary colors at that time are mixed. Record the energy amount of
This is an experiment for finding a color matching function. The “color matching function” is a function of the energy intensity at each wavelength of these three primary colors as a function. The color matching function derived by this experiment has a portion showing a negative energy value. This means that, in theory, any color can be formed by a combination of three primary colors, but in reality, there is a color that cannot be reproduced even with the three primary colors because negative energy intensity cannot be output.

As a specific example, in order to match the color with monochromatic light of, for example, 500 nm, the energy of the red primary color light must be negative. That is, the range of colors that can be reproduced by actually mixing color lights differs depending on how the three primary colors are selected. When a certain set of primary colors is given, a range of colors that can be reproduced by mixing the primary colors is called a “color reproduction area (Color Gamut)” of the primary colors. That is, also in the color image display device, the color reproduction range is determined by the color development of the three primary colors themselves. For example, in a CRT display, the color reproduction range is largely determined by the color development of the phosphor.
As explained at the beginning, the conventional CRT, LCD, PD
The reason why the color reproduction range that can be displayed by P, LED, and the like is narrow is that the color reproduction of these three primary colors themselves is limited.

The color matching function has the following properties. First, the color matching functions [r], [g], [b] (usually displayed with a bar, but for convenience here are displayed with square brackets and displayed as [r]) are arbitrary colored light. S is a weighting function for each wavelength for obtaining the intensities r, g, and b from the color light S itself when adjusting the intensities of the given three primary colors R, B, and G. That is, the color light having the spectral energy of S is the three primary color lights R, B, and G, and the expression S≡r
Assuming that the colors are equalized in the form of R + gG + bB (≡ is a relation of equal colors), r = S · [r], g = S · [g], b
= S · [b]. Colors that people see the same color are the same 3
It can be seen that the image signal for displaying the image while maintaining the metamerism needs to have the sensitivity of the color matching function so that the color is measured by the primary color values. This principle is actually used also in a color image display device such as a color television. The color television adjusts the amount of the electron beam applied to the phosphors of the three primary colors of red, green, and blue, and makes the color light S equal in color. Then, the intensity is measured by a television camera having a photosensitive element as an image pickup element such as a CCD having a color filter having three sensitivities approximating the respective color matching functions.

Although a detailed description is omitted, this color matching function is a linear conversion of the sensitivity of the three types of cones of the human retina, and the color matching functions have a linear conversion relationship. Therefore, it can be said that all the color matching functions can be transferred by a linear transformation. In order to perform color matching with the three primary color lights, an image signal must be generated with the sensitivity of the color matching function. Therefore, the condition for generating the image signal must be a linear conversion of the color matching function. This is called "router condition". It can be said that all the color lights can be color-matched by three independent color lights S. However, this is because the image signal is formed by any three independent spectral sensors regardless of the spectral distribution, and the result can be linearly converted. In order to generate an image signal that does not always provide a correct image display but accurate color reproduction, it is necessary to use one of the color matching functions.
One must do. If the spectral sensitivity of the image signal generation sensor does not have a color matching function, a correct image signal cannot be obtained by linear conversion. The value (r, g, b) of the obtained image signal is an intensity for equalizing the color light with the three primary colors R, G, B corresponding to the color matching function. The fact that the spectrum of the sensor is a color matching function is a condition for realizing metamerism,
If this is not the case, light that looks different to the human eye may be measured to the same color or vice versa. Furthermore, it can be said that the tristimulus values are linear transformations of the tristimulus values for the three cones. In the above sense, 3
It can be said that the stimulus values are shifted by linear transformation, but the condition is that the three stimulus values are correctly sensed by the color matching function. Therefore, the laser oscillator 13 of each wavelength for forming an image
And the image signal for driving the same must have the same color matching function. Therefore, an accurate color reproduction by the auxiliary laser oscillator 13G ₂ is the oscillation wavelength 50
The wavelength of 0 nm needs to be sensed by the sensor.

As described above, since the tristimulus values are shifted by a linear transformation, an arbitrary set of three primary colors can be determined to measure the color, and the tristimulus values can be measured by the color matching function determined thereby. However, it is convenient to use a standard color matching function for the sake of convenience in order to quantitatively express the color.
° The XYZ system of the field of view is S as the CIE-1931 XYZ system.
standard Colorimetric Obse
rver is determined and used. Here, this CI
The description will be made using the E-1931XYZ system.

The color matching functions [x], [y], [z] (usually displayed with a bar, but here are displayed with square brackets for convenience, such as [x]) are described above. [R],
[G] and [b] are linearly transformed. For convenience of calculation, each color matching function has a positive value over all wavelength bands.
[Y], one of the color matching functions, matches the illuminance function of the eye,
The relative magnitudes of [x], [y], and [z] are as follows. When the equal-energy white is measured at this sensitivity, the tristimulus values ([X], [Y], [Z]) are plotted on the graph. [X] = [Y] = [Z] so that the area under the curve is constant. Because of this property, the three primary colors X, Y, and Z corresponding to this color matching function are color lights that do not actually exist. CI using color matching functions [x], [y], [z]
According to the E-1931XYZ system, the color of the color light S is [X]
= S · [x], [Y] = S · [y], [Z] = S ·
It is represented by the tristimulus value of [z].

When it is desired to express the color light S by brightness and color components, it is also expressed by luminance Y and chromaticity (x, y).
The chromaticity (x, y) is defined by the following equation. x = [X] / ([X] + [Y] + [Z]) y = [Y] / ([X] + [Y] + [Z]) The chromaticity has the same ratio of energy at each wavelength. A chromaticity diagram is often used to indicate a color reproduction range in a certain mixed color system even if it changes. Here, FIG.
FIG. 9 is a diagram illustrating a CIE chromaticity diagram using XYZ chromaticity coordinates according to Z8701 (a color display method using an XYZ color system).

Further, color matching functions [x], [y], [z]
Is a tristimulus value that matches a single light color from its definition,
The chromaticities x (λ) and y (λ) of a single light color are x (λ) = [x] (λ) / ([x] (λ) + [y]
(Λ) + [z] (λ)) y (λ) = [y] (λ) / ([x] (λ) + [y]
(Λ) + [z] (λ)).

In FIG. 3, the chromaticity x of this single light color
When (λ) and y (λ) are drawn on the chromaticity diagram, a substantially horseshoe-shaped curve is drawn as shown by SP in FIG. This curve is called a spectrum locus SP (spectral locus),
The spectrum locus SP and the inside of the figure connecting both ends with line segments are the range of colors existing in the world. This is because the chromaticities x (λ) and y (λ) of the single light color are on the spectrum locus SP, and all colors other than the single light color are obtained by mixing the single light colors. This is because the chromaticities x (λ) and y (λ) of the mixed colors exist on a straight line connecting the chromaticities of the two colors.

FIG. 4 is a diagram showing the color gamut of a conventional image display device in this CIE chromaticity diagram ("Advanced technology of display", 1998).
(September 25, Chitani Tani, Kyoritsu Shuppan, pp. 183). LCD (Liquid Crystal Display), CRT
(Cathode ray tube), NTSC color television, PDP
(Plasma display panel) and an image display device using an LED (light emitting diode) each have a limit on the wavelength of the color of the luminous body, which is the three primary colors, and because it is not a single wavelength, color turbidity occurs, and the color reproduction range Was narrow. Compared with these, an image display device using an LS (laser scanner display) has a laser oscillator that emits three primary colors capable of reproducing a single wavelength and pure color without turbidity. Due to the fact that laser light can be oscillated, a much wider color display area can be achieved as compared with image display devices of other types, such as a triangle shown by LS in FIG. It became so.

FIG. 5 is a diagram showing the color gamut of the projection display apparatus 1 of the present embodiment in the CIE chromaticity diagram. Conventionally, as shown in FIG. 4, no matter which method is used, color mixing is performed using three primary colors, and the position of the triangle is determined in the horseshoe shape drawn by the spectrum trajectory SP. Also could not cover this spectrum locus SP. In particular, the conventional 3
The challenge was to expand the limits of primary color development, and was not a problem at all until eliminating visible light wavelengths that could not be reproduced. Under these circumstances, the development of various types of lasers including semiconductor lasers has greatly increased the types of oscillation wavelengths of laser oscillators, and laser scanner displays have been able to perform high-speed and high-precision scanning. A projection display device using a laser oscillator capable of oscillating a wavelength has become possible. However, in the case of using the conventional three primary colors, there are areas of colors that cannot be reproduced, and natural colors cannot be reproduced because of the areas of colors that cannot be reproduced. For example, the green of the trees in the fresh green season,
Although it is a color close to a pure color with a wavelength of around 500 nm, such a transparent green having a large saturation cannot be reproduced by any conventional method. In the projection display device 1 of the present embodiment, the color in the range of the quadrangular shape as shown in FIG. 5 is reproduced by using the fourth color of the auxiliary laser light for the color mixture, and the color reproduction range is expanded. , Enabling natural color reproduction.

In this embodiment, only one auxiliary laser beam is used and the image signal has four colors. However, the use of a plurality of auxiliary lasers makes it possible to expand the color reproduction range. Needless to say.

Here, generation of an image signal suitable for the projection display device 1 will be described. The image signal is a CCD (Charge Couple) (not shown) that generates a video signal.
dDevice) is generated using a video camera. According to the above-described metamerism, it is desirable to use a sensor and a luminous body having the same wavelength for color measurement and reproduction. It is necessary to use four colors according to the oscillator 13. Here, FIG.
FIG. 3 is a diagram schematically showing color filters arranged on a CCD for image reading. As shown in FIG. 6, the laser beam L oscillated by the laser oscillator 13
Red filter FR, green filter FG ₁ , and blue filter F, which are four filters corresponding to the wavelength of B
B, auxiliary filters FG ₂ (hereinafter referred to as filters F) are arranged in a matrix. Through this filter F, a signal corresponding to each laser oscillator 13 is generated.

Hereinafter, the filter F will be described in detail. FIG. 7 is a graph GFR showing the spectrum of the wavelength transmitted by the red filter FR, and a graph G13 showing the oscillation spectrum of the red laser oscillator 13R shown for comparison.
It is a figure showing R. As can be seen from this graph, in order to generate a red image signal as described above, a red filter FR is applied to a CCD so as to correspond to the sensor and red light is recorded as an image signal, and light of other wavelengths is recorded. Is cut. However, the reason why the width of the input wavelength is made wider than the wavelength output from the laser oscillator 13R is to secure the light quantity at the time of signal formation. This filter FR
Can be a broadband filter, so that a dye filter that is easy to manufacture and has low cost can be used. In addition,
Light rays with wavelengths longer than 780 nm are not visible light,
In order to correct the infrared sensitivity of the CCD, an infrared cut filter such as CM-500 is installed in advance.

[0050] Figure 8 is a graph GFG ₀ showing the spectrum of a wavelength transmission of conventional green filter FG _0, it is a diagram showing a graph G13G ₁ representing the oscillation spectrum of the green laser oscillator 13G ₁ shown for comparison. In conventional green filter, since narrowband filter is not required, such as in the auxiliary filter FG ₂ of the present embodiment as described below, it is possible to use the same broadband filter and a red filter FR. Note that the conventional green laser oscillator is the green laser oscillator 1 of the present embodiment.
3G ₁ to indicate the same oscillation wavelength and a conventional green laser oscillator is also described as a 13G _1.

FIG. 9 shows a blue filter F of this embodiment.
A graph GFB showing the spectrum of the wavelength transmitted by B;
It is a figure showing graph G13B showing the oscillation spectrum of blue laser oscillator 13B shown for comparison. In this case, and a red filter FR above, to input the image signal in the same wide-band filter and a conventional green filter FG _0.

[0052] Figure 10 is a diagram showing a graph GFG ₂ showing a spectrum of a wavelength that transmits the in this embodiment, the graph G13G ₂ representing the oscillation spectrum of the auxiliary laser oscillator 13G ₂ shown for comparison. Auxiliary laser oscillator 13G ₂ for oscillating a wavelength of 500nm, in broadband filter, such as a conventional green filter FG ₀ as described above, since close to the wavelength of the green laser oscillator 13G _1, narrow narrowband wavelength ranges transmitted through It becomes necessary to use a filter. Therefore, as shown in GFG ₂ in FIG. 10, using filters FG ₂ narrowband. Since this narrow band filter cannot be manufactured with a dye filter, transmitted light is selected using an interference filter.

Meanwhile, FIG. 11 is a graph GFG ₁ showing the spectrum of wavelengths transmitted through the green filter FG ₁ of the present embodiment, green laser oscillator 13G shown for comparison
It is a diagram showing a graph G13G ₁ representing _one of the oscillation spectrum. In this case, so as not to overlap with the oscillation wavelength of the auxiliary laser oscillator 13G _2, below around 510nm is using filters FG ₁ which does not pass through.

FIG. 12 shows conventional filters FR and F.
G ₀ , a graph G showing the spectrum of the wavelength transmitted by the FB
_FR, is a diagram illustrating the GFG 0, GFB, the laser oscillator 13R shown for _comparison, the graph represents the oscillation spectrum of the 13G _1, 13B G13R, the G13G 1, G13B. As shown here, conventionally, since the wavelengths of the three primary colors are far apart, it was possible to use a wide-band filter and transmit a wide range of wavelengths.

FIG. 13 shows a filter F of this embodiment.
_{R, FG 1,} FG _2, graphs showing the spectrum of the transmitted wavelength of FB _GFR, and GFG _1, GFG _{2, GFB,}
Laser oscillator 13R shown for comparison, _13G 1, 13
Graph representing the oscillation spectrum of G _2, 13B G13R,
G13G _1, a diagram illustrating a G13G _2, G13B. As shown in the figure, the oscillation wavelength G13G ₁ green laser oscillator 13G ₁ and the auxiliary laser oscillator 13G _2, G13G ₂ are close, by using a filter of a narrow band, as described above, the auxiliary laser oscillator 13G ₂ can be obtained.

CCD equipped with the filter F as described above
A video camera generates image information into a video signal.
This method is the same as the generation of a well-known video signal except that a four-color signal is obtained by adding an auxiliary signal for an auxiliary laser beam in addition to the RGB signal.

Next, the operation of displaying an image on the projection display device 1 based on the image signal generated as described above will be described with reference to FIGS. The image information generated as described above is input as a video signal via the interface 48 from a CCD video camera or a video deck for reproducing a tape or the like on which the image information is recorded.
The input video signal is input to an image input unit 47 as RG
B and an auxiliary signal. Based on the separation signal, the control unit 40 sends a control signal of the polygon mirror to the polygon mirror control unit 16 and sends a control signal to the laser oscillator control unit 15 so as to synchronize with the rotation of the polygon mirrors 17 and 18. oscillator control unit 15, the laser oscillator 13R, _13G 1, 13
A drive signal is sent to G ₂ and 13B.

The laser beams LB (R), LB (G ₁ ), LB (B), LB (G ₂ ) thus emitted
Are combined into one optical path by the laser combiner 14,
The main scanning polygon mirror 17 scans the screen 50 in the horizontal direction X. However, the main scanning is performed on the screen 5
In consideration of the error in the projection direction to 0, the laser beam LB is started from slightly above in FIG. 2 and is incident on the sub-scanning beam sensor 20 provided near the scanning start position direction of the screen 50. 20 to control unit 40
The modulation of the laser beam LB is not started until the SOS signal is sent to the controller. S from the sub-scanning beam sensor 20
When the OS signal is present and the laser beam LB is incident on the main scanning beam sensor 19, the SOS signal is transmitted from the main scanning beam sensor 19 to the control unit 40, and the control unit 4
0 starts modulation of each laser oscillator 13 based on the image signal so that an image is projected from a predetermined position on the screen 50 based on the SOS signal. When one main scan is completed as described above, the emission direction of the laser beam LB moves to the next main scan line by the sub-scanning polygon mirror 18, so that the SO beam transmitted by the main scanning beam sensor 19 is returned again.
The main scanning of the next row is performed by the S signal.

In this way, the main scanning is performed 525 times on the screen 50 by the laser beam LB, and one screen is displayed every 1/30 second. By performing high-speed and fine scanning in this manner, a full-color screen for expressing colors that could not be expressed conventionally can be continuously displayed with high luminance, and a smooth moving image can be displayed.

In this case, the auxiliary laser oscillator 13G
The oscillation wavelength of No. ₂ is in a relationship of a substantially complementary color to the oscillation wavelength of the red laser oscillator 13R. As described above, by emitting an auxiliary laser oscillator 13G ₂ 500 nm laser beam LB (G
_In the case where the red laser oscillator 13R emits light even when ₂ ) is oscillated, it is determined on the straight line connecting two vertexes indicating each of the squares shown in FIG. Color. Also, there must be emitting auxiliary laser oscillator 13G ₂ As can be seen from FIG. 5 is a color of a region of the left part of the broken line in FIG. 5, only if the red laser oscillator 13R is hardly emission Can be Conversely, if when the red laser oscillator 13R is emitting light low means for emitting auxiliary laser oscillator 13G _2. Therefore, in the present embodiment, on condition that the red laser oscillator 13R does not emit light, and controls so as to emit the auxiliary laser oscillator 13G _2.
By doing so, unnecessary auxiliary laser oscillator 13G
₂ are excluded. Conversely, the auxiliary laser oscillator 13
May be controlled so as to cut the emission of the red laser oscillator 13R if the image signal to emit G ₂ is input. Also in this case, when a color having a wavelength of about 500 nm is displayed, if the red laser oscillator 13 </ b> R emits light, color reproduction becomes turbid, and it becomes difficult to reproduce a clear color of a wavelength of about 500 nm. Moreover, in this way, the auxiliary laser oscillator 13G _2, the main laser oscillator 1
The exclusive use of any of the 3Ms simplifies control. And power saving can also be measured. The same applies to a case where there are a plurality of auxiliary laser oscillators, and the same advantage can be obtained by simultaneously lighting up to three lamps.

Since the projection display device 1 has the above-described configuration and operation, it is possible to reproduce colors and the like that could not be reproduced conventionally, a wide range of colors that can be reproduced, and beautiful colors faithful to more natural colors. There is an effect that a color image can be displayed.

Although the present invention has been described based on one embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Can be implemented. For example, a semiconductor laser and an SHG (nonlinear optical element) may be used as the laser oscillator. Furthermore, a semiconductor laser array that emits a plurality of laser beams from a single package may be used.

[0063]

As is apparent from the above description, claim 1
According to the projection display device of the invention, the three types of main laser light having the wavelengths of the three additive primary colors and the auxiliary laser light having a wavelength different from the wavelengths of the three primary colors are oscillated based on the image signal. An auxiliary laser beam, comprising: a laser oscillator; and a laser scanner that integrally scans laser beams of respective wavelengths emitted from the laser oscillator and projects a desired image on a predetermined screen. The use of the light of the color (3) has an effect that a color that cannot be reproduced by the light of the wavelengths of the three primary colors can be reproduced. Therefore, there is an effect that color reproduction closer to a natural color can be performed.

In the projection display device according to the second aspect of the present invention,
In addition to the effect of the projection display device according to claim 1, the auxiliary laser beam is oscillated only when at least one type of main laser beam among the main laser beams is not oscillated. There is an effect that control for oscillating laser light only when necessary can be performed.

In the projection display device according to the third aspect of the present invention,
In addition to the effect of the projection display device according to claim 1 or claim 2, the auxiliary laser beam is set at approximately 500 nm, and therefore, cannot be emitted particularly with the conventional three primary colors. There is an effect that colors near 500 nm can be reproduced.

In the projection display apparatus according to the fourth aspect of the present invention,
In addition to the effects of the projection display device according to any one of claims 1 to 3, the image signal corresponds to an image signal corresponding to the wavelength of the three primary colors and a wavelength different from the wavelength of the three primary colors. Since the image display apparatus is characterized by being generated by an image signal, a projection display device including a laser oscillator that oscillates auxiliary laser light has an effect that suitable control can be performed using the image signal. for that reason,
Further, there is an effect that color reproducibility can be improved.

[Brief description of the drawings]

FIG. 1 is a projection display device 1 according to an embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating the main configuration of FIG.

FIG. 2 is a schematic diagram illustrating a laser scanner unit 10;

FIG. 3 is a diagram illustrating a chromaticity diagram using XYZ chromaticity coordinates according to JIS Z8701 (a color display method using the XYZ color system) for x and y.

FIG. 4 is a diagram showing a color gamut of a conventional image display device in a CIE chromaticity diagram.

FIG. 5 is a diagram showing a color gamut of the projection display device 1 according to the present embodiment in the CIE chromaticity diagram.

FIG. 6 is a diagram schematically showing color filters arranged on a CCD for image reading.

FIG. 7 is a diagram showing a graph GFR showing a spectrum of a wavelength transmitted by a red filter FR of the present embodiment and a graph G13R showing an oscillation spectrum of a red laser oscillator 13R shown for comparison.

FIG. 8 shows a conventional green filter FG.₀Of the transmitted wavelength
Graph GFG showing spectrum ₀And shown for comparison
Green laser oscillator 13G₁Graph representing the oscillation spectrum of
G13G₀FIG.

FIG. 9 is a diagram showing a graph GFB showing a spectrum of a wavelength transmitted by the blue filter FB of the present embodiment and a graph G13B showing an oscillation spectrum of a blue laser oscillator 13B shown for comparison.

A graph GFG ₂ showing a spectrum of a wavelength transmission of Figure 10 the auxiliary filter FG ₂ of the present embodiment, a diagram showing a graph G13G ₂ representing the oscillation spectrum of the auxiliary laser oscillator 13G ₂ shown for comparison.

A graph GFG ₁ showing the spectrum of wavelengths transmitted through the green filter FG ₁ in FIG. 11] This embodiment illustrates a graph G13G ₁ representing the oscillation spectrum of the green laser oscillator 13G ₁ shown for comparison.

FIG. 12 shows conventional filters FR and FG.₀, FB transmission
Graphs GFR, GFG showing the spectrum of the wavelength to be changed₀,
GFB and laser oscillators 13R, 13R shown for comparison.
G ₁, A graph G13R representing the oscillation spectrum of 13B,
G13G₀, G13B.

FIG. 13 shows filters FR, FG ₁ , F of the present embodiment.
G ₂ , a graph G showing the spectrum of the wavelength transmitted by FB
_{FR, GFG 1, GFG 2,} GFB and laser oscillator _13R shown for comparison, 13G _1, 13G 2, 13B graph represents the oscillation spectrum of the G13R, G13G _1, G
It is a diagram illustrating a 13G _2, G13B.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Projection display apparatus 2 Main body 10 Laser scanner unit 11 Scanner 12 Scanner control unit 13 Laser oscillator 13R Red laser oscillator 13G ₁ Green laser oscillator 13B Blue laser oscillator 13G ₂ Auxiliary laser oscillator 14 Laser beam synthesizer 14A First laser beam synthesizer 14B Second laser beam synthesizer 14C Third laser beam synthesizer 15 Laser oscillator controller 16 Polygon mirror controller 17 Main scanning polygon mirror 18 Sub scanning polygon mirror 19 Main scanning beam sensor 20 Sub scanning beam sensor 40 Control unit 47 Image input unit 48 interface 50 screen 51 fθ lens LB laser beam LB (R) red laser beam LB (G ₁ ) green laser beam LB (B) blue laser beam LB (G ₂ ) auxiliary laser beam

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[Procedure amendment]

[Submission date] January 12, 1999 (1999.1.1)
2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Projection display device

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display apparatus which projects a laser beam and scans the laser beam to display it on a screen, and more particularly to a projection display apparatus having an auxiliary laser oscillator.

[0002]

2. Description of the Related Art Conventionally, in a color image display device,
Various methods have been proposed to faithfully reproduce the color. Here, the color existing as visible light is a so-called color as represented in the CIE1931 chromaticity diagram of the XYZ color system (2 ° field of view) of the CIE (International Commission on Illumination) based on JISZ8701 shown in FIG. As shown in FIG. 4, the range of the spectrum locus that has a horseshoe shape can be reproduced in the case of additive color mixture using three primary colors.
The colors are in the range inside the triangle with the vertices representing the positions of the primary colors on the figure. As a color image display method,
For example, there is a color display using a CRT (cathode ray tube) or an LCD (liquid crystal display).
TSC (National Television S)
high-definition television, PDP (plasma display), LE
Although there is a color display using D (light emitting diode), color reproducibility has been improved in recent years.

Further, as described in JP-A-1-245780, JP-A-3-65916, and JP-A-4-181289, three primary colors of additive color mixing, red (hereinafter R) and green ( Hereinafter, G) and blue (hereinafter B) laser lights are oscillated, and the optical paths of the laser lights output from these laser oscillators are combined into one to perform simultaneous additive color mixing, and the combined laser lights are put on a screen. There has been proposed a projection display apparatus that projects a color image and two-dimensionally scans the image to display a color image or the like on a screen. In such a projection display device, a laser oscillator capable of emitting a wide range of colors in a frequency band close to a single wavelength by a semiconductor laser or the like is used for three primary colors of additive color mixture.
It has become possible to display a color with a wide color reproduction and no turbidity.

[0004]

However, the range of color reproduction is limited to the inside of a triangle having the vertices of the three primary colors as shown in the figure. Even if the position of this triangle is enlarged and moved,
In the horseshoe-shaped range described above, there is a problem that a portion that cannot be covered by the triangle is formed, that is, a large amount of colors that cannot be reproduced remain, and it is difficult to reproduce natural colors.

An object of the present invention is to solve the above-mentioned problems and to provide a projection display device capable of displaying a more natural and beautiful color image with a wide range of reproducible colors.
And

[0006]

According to a first aspect of the present invention, there is provided a projection display apparatus according to the first aspect, wherein three types of main laser beams having wavelengths of three primary colors of additive color mixture are used based on an image signal. A laser oscillator that oscillates auxiliary laser light having a wavelength different from the wavelengths of the three primary colors, and a laser beam of each wavelength oscillated from the laser oscillator, and integrally scans the desired image on a predetermined screen. And a laser scanner for projecting light.

[0007] In the projection display device of the invention according to this configuration,
By using light of the color of the auxiliary laser light, it is possible to reproduce colors that cannot be reproduced with light of the wavelengths of the three primary colors,
Color reproduction closer to a natural color can be performed.

[0008] In the projection display device according to the second aspect of the present invention,
In addition to the configuration of the projection display device according to the first aspect, the auxiliary laser light is oscillated only when at least one type of main laser light among the main laser lights is not oscillated.

[0009] In the projection display apparatus of the invention according to this configuration,
Control to oscillate the auxiliary laser light only when necessary can be performed.

[0010] In the projection display device according to the third aspect of the present invention,
In addition to the configuration of the projection display device according to claim 1 or 2, the auxiliary laser beam is set to approximately 500 nm.

[0011] In the projection display device of the invention according to this configuration,
A color near 500 nm, which could not be obtained with the conventional three primary colors, can be reproduced.

According to the projection display apparatus of the invention according to claim 4,
In addition to the configuration of the projection display device according to any one of claims 1 to 3, the image signal corresponds to an image signal corresponding to the wavelength of the three primary colors and a wavelength different from the wavelength of the three primary colors. And an image signal.

[0013] In the projection display device of the invention according to this configuration,
In a projection display device including a laser oscillator that oscillates auxiliary laser light, suitable control can be performed using this image signal, and color reproducibility can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a projection display device according to the present invention will be described by way of a preferred embodiment with reference to the accompanying drawings. Here, FIG. 1 is a schematic diagram illustrating a main configuration of a projection display device 1 according to an embodiment of the present invention.
First, the outline of the configuration of the projection display device 1 will be described with reference to FIG.

As shown in FIG. 1, the projection display device 1 includes a laser scanner unit 10, a control unit 40,
The image input unit 47 includes a screen 50 on which a laser beam LB is projected from the main body 2 to display an image.

In the projection display device 1, a signal is sent from the control unit 40 to the scanner control unit 12 based on the image data input to the image input unit 47 via the interface 48, and the laser oscillator of the scanner control unit 12 red laser oscillator 13R which drive signal is provided in the laser scanner unit 10 is generated by the control unit 15, a green laser oscillator 13G _1,
A blue laser oscillator 13B (see FIG. 3, hereinafter collectively referred to as a main laser oscillator 13M) and an auxiliary laser oscillator 13G ₂ (collectively referred to as a laser oscillator 13).
Are oscillated, the red laser beam LB (R), the green laser beam LB (G ₁ ), and the blue laser beam LB (B)
(Hereinafter, these are collectively referred to as a main laser beam LB (M).) And an auxiliary laser beam LB (G ₂ ) (the above is collectively referred to as a laser beam LB).
The laser beam LB is projected on the screen 50 while being two-dimensionally scanned by a main scanning polygon mirror (rotating polygon mirror) 17 and a sub-scanning polygon mirror 18 (hereinafter collectively referred to as polygon mirrors 17 and 18) to form an image. Is what you do.

The control unit 40 includes a CPU (not shown) and a RAM (not shown).
And a well-known computer having a ROM. A program for controlling the entire projection display device 1 is stored in the ROM.
The polygon mirror 1 performs input processing and data expansion by U and modulates light emission of the laser oscillator 13 of the laser scanner unit 10 based on image data based on the image data.
The projection is performed while synchronizing with the images 7 and 18, and the screen of the screen 50 is two-dimensionally scanned to display an image on the screen 50.

The screen 50 receives the laser beam LB and diffuses and transmits the laser beam LB so that an image can be observed by a user. The screen 50 is formed of a translucent milky white diffusing plate. In the present embodiment, the screen 50 and the main body 2 are configured as an open type that can be separated and movable, but they are integrated into a closed type in which the laser beam LB is not directly visible to the user. It may be configured. Further, the screen 50 may be such that the screen 50 is projected on a large screen constituted by a reflection diffusion plate. In short, the screen 50 can be of any type as long as the screen can be projected by the laser scanner unit 10 provided in the main body 2 and an image can be displayed.

FIG. 2 is a schematic diagram for explaining the laser scanner unit 10. As shown in FIG. Hereinafter, the structure and operation of the laser scanner unit 10 will be described with reference to FIG. First, the laser oscillator 13 includes a laser oscillator that oscillates a specific color.
A Kr laser is used for the red laser oscillator 13R that emits red light of 00 nm, and a He-Cd laser is used for the blue laser oscillator 13B that emits blue light of 450 nm.
The auxiliary laser oscillator 13G ₂ that emits bright green light of the green laser oscillator 13G ₁ and 500nm for emitting green light of nm, Ar laser is preferably used.

The laser beams LB (R), LB (G ₁ ) emitted from these four laser oscillators 13,
LB (B) and LB (G ₂ ) have one optical path by a first laser beam combiner 14A, a second laser beam combiner 14B, and a third laser beam combiner 14C (hereinafter, referred to as laser beam combiner 14). Into a laser beam LB.

Firstly red laser oscillator 13R and the green laser oscillator 13G ₁ is synthesized by the first laser beam combiner 14A. The first laser beam combiner 14A is composed of a dichroic mirror (wavelength selective reflector) coated with a specific wavelength transmitting and reflecting other wavelengths, and the laser beam emitted from the red laser oscillator 13R. LB (R) is to be transmitted, the green laser beam LB (G emitted from the green laser oscillator 13G _1
1 ) is made of a material that reflects light depending on the wavelength of output light. Therefore, the first laser beam combiner 14A
Orthogonally disposed a red laser oscillator 13R and the green laser oscillator is emitted from each of 13G ₁ red laser beam LB (R) and the green laser beam LB _{(G 1)} is
The red laser beam LB (R) passes through the dichroic mirror and travels straight, while the green laser beam LB (G ₁ ) is reflected by the dichroic mirror and its optical axis is deflected at right angles. And adjusted to have the same optical axis.

Similarly, a red laser beam LB (R) and a green laser beam LB (G ₁ ) are synthesized by a second laser beam synthesizer 14B and further a blue laser beam emitted by a blue laser oscillator 13B. LB
(B) is synthesized, and the main laser beam LB (M) is synthesized.

In addition to the main laser beam LB (M) thus generated, the third laser beam combiner 14C further converts the main laser beam LB (M) into an auxiliary laser beam LB (G ₂ ). The screen is scanned by the combined laser beam LB.

The synthesis of the laser beams LB of these three colors may be a dichroic prism or a configuration in which the luminous flux is synthesized by a prism using a difference in the refractive index depending on the wavelength. It suffices if the three light beams are combined into one light path.

Next, the laser beam LB of the projection display device 1
Will be described with reference to FIGS. 1 and 2. FIG. The laser beam LB emitted by the laser oscillator 13 and combined into one light beam by the laser beam combiner 14 contacts the main scanning polygon mirror 17 rotating at high speed. The main scanning polygon mirror 17 has a regular hexagonal prism shape having a height lower than the bottom surface as shown in FIG. 2, and is disposed at a position where a rotation axis is horizontal and a line perpendicular to the laser beam LB is translated upward. The laser beam L
B is reflected downward by the six plane mirrors rotating about the rotation axis, and the direction of the optical axis is set such that the rotation of the main scanning polygon mirror 17 increases the internal angle of the laser beam LB with the optical axis before reflection. Changes to

At this time, the laser beam LB reflected by the main scanning polygon mirror 17 is not projected outside the range of the predetermined angle, so that the laser oscillator control unit 15 and the polygon mirror control unit provided in the scanner control unit 12 are provided. 16. Further, in order to harmonize the control by the laser oscillator control unit 15 and the polygon mirror control unit 16, the optical axis of the laser beam LB reflected by the main scanning polygon mirror 17 is changed to the light beam of the laser beam LB at the main scanning start position. The main scanning beam sensor 19 is located near the passing position.
Is provided, the actual position of the laser beam LB is detected, and the light emission timing of the laser oscillator 13 is adjusted to the rotation of the main scanning polygon mirror 17. Here, the light received by the main scanning beam sensor 19 is sent to the control unit 40 as a signal, and this signal is hereinafter referred to as a main scanning SOS (Start).
This signal is referred to as “Of Scanning” signal. This main scanning SO
Upon detecting the S signal, the control unit 40 sets the laser oscillator control unit 1 based on the scanning start position calculated based on this signal.
5, a signal for laser emission modulated based on the image data is transmitted. In this manner, a signal modulated by one column of data is sent to a laser oscillator 13 by a laser oscillator control unit 15 which is a driving unit (driver) of the laser oscillator, and a laser beam LB is transmitted to a sub-scanning polygon mirror 18. And is scanned in the X direction of FIG. 2 on the screen 50, and an image for one line is projected on the screen.

On the other hand, the laser beam LB reflected and deflected by the main scanning polygon mirror 17 is reflected toward the sub-scanning polygon mirror 18 located therebelow in FIG. The sub-scanning polygon mirror 18 has a shape of an elongated hexagonal prism having six plane mirrors and a height higher than the bottom surface, and its rotation axis is horizontal, parallel to the screen 50, and is screened by the main scanning polygon mirror 17. The plane mirror is arranged at a position slightly displaced in the opposite direction to 50, and the longitudinal direction of the plane mirror is arranged in the same direction as the direction deflected by the main scanning polygon mirror 17. Then, the sub-scanning polygon mirror 18 rotates in a direction in which the upper end approaches the screen 50. Therefore, the laser beam LB reflected from the main scanning polygon mirror 17 is further deflected in the direction of the screen 50 so that the inner angle to be deflected increases with time, that is, in the Y direction of the screen 50. The direction of movement changes.

As described above, the sub-scan is performed in the vertical direction while performing the horizontal main scan. This is a scan similar to the horizontal scan and the vertical scan of a conventional well-known CRT. When horizontal scanning is repeatedly performed from the upper end to the lower end in this manner, one screen is displayed. However, since the sub-scanning polygon mirror 18 rotates at a constant speed, the control unit 40 sends a signal at an appropriate interval. . Then, the sub-scanning of the next screen can be performed on the next mirror surface of the rotating sub-scanning polygon mirror 18. This sub-scanning can be performed by using a galvanometer (oscillating single-sided mirror) that controls the tilt by the current. However, using a polygon mirror has less change in angular velocity than using a galvanometer. In particular, it is preferable to use a polygon mirror.

Strictly speaking, the sub-scanning polygon mirror 18 rotates while the main scanning polygon mirror 17 scans one main scanning line. Scanning polygon mirror 18
Are set in such a manner that the main scanning direction is slightly lowered.

Further, in order to detect the vertical scanning start position, the laser oscillator 13 is turned on slightly above the original scanning start position on the screen 50, and the laser beam LB is emitted without modulation and the main scanning is performed. And sub-scanning. Then, when the laser beam LB is incident on the sub-scanning beam sensor 20 arranged near the scanning start position, a sub-scanning SOS signal is sent from the sub-scanning beam sensor 20 to the control unit 40. The actual scanning start position is calculated, and after the calculated predetermined time, the laser scanner unit 1
A control signal is sent to the scanner control unit 12, and the scanner control unit 12 sends a drive signal to the laser oscillator 13 to modulate the light amount, and the main scanning and the sub-scanning are started.

As described above, the image displayed on the screen 50 by the laser beam LB shows pincushion-like distortion on both sides, and a gap between the scanning lines in the vertical direction occurs. Therefore, in the control unit 40, it is preferable to control the distortion correction by extending the modulation time for scanning the central part or shortening the modulation time at the upper end and the lower end. It is desirable to optically correct the distortion using a method such as the above.

In this embodiment, the scanning of 525 main scanning lines (horizontal scanning lines) for one screen is reduced to 1/3 in this embodiment.
The sub-scanning (vertical scanning) of 0 seconds is performed, and a smooth screen with little flicker can be projected.

Returning to FIG. 1, the description will be continued. As described above, the scanner controller 12 includes the laser oscillator controller 15 and
And a polygon mirror controller 16. The laser oscillator control unit 15 uses the weak signal transmitted from the control unit 40 as a drive signal as the drive signal of the laser oscillator 13 (see FIG. 2).
Driver to send to The polygon mirror control unit 16 also receives a weak signal from the control unit 40, and receives a main scanning polygon mirror 17 and a sub-scanning polygon mirror 18.
Is a driver that sends out a drive signal for driving a motor that rotates.

The image input section 47 is a buffer for externally inputting and storing image data to be projected, and is also a place for separating the image data into respective control signals.
It has storage means. As input data, a video signal is input via the interface 48. Of course, the data of the image information is not limited to the video signal, and it is sufficient if the image information can be read by some method. In the projection display device 1 according to the present embodiment, an input signal is obtained by adding an auxiliary signal to an RGB video signal, using image signals of video signals of four colors, and generating an image based on these signals.

Here, the image signal will be described.
First, the color perceived by the human eye will be described. The color perceived by the human eye is a stimulus received by three types of cones of the retina.
It is governed by the stimulus value. And Grassman (Gra
As is known by the law of sssmann), all color lights can be made equal by a mixture of three independent color lights (metamerism, Metamerism)
It has been known. "Metamerism" refers to the inability of a person to distinguish between two types of light with different spectral compositions that produce equal tristimulus values under the same circumstances. The term "independent three colors" means that one of the two colors cannot be equalized with the other two colors.

However, this is not an accurate expression, and will be further described as follows. For example, C
Red (R) primary color light is λ = 700n as in the IE standard.
m, the primary color of green (G) is monochromatic light of λ = 546.1 nm, and the primary color of blue (B) is monochromatic light of λ = 435.8 nm. Then, a color matching experiment is performed using these three colors. Here, the "color matching experiment" means that RGB three color light sources are prepared, the energy intensity of each light source is adjusted to make a mixture, and the mixed light is arbitrarily colored, and the three primary colors at that time are mixed. Record the energy amount of
This is an experiment for finding a color matching function. The “color matching function” is a function of the energy intensity at each wavelength of these three primary colors as a function. The color matching function derived by this experiment has a portion showing a negative energy value. This means that, in theory, any color can be formed by a combination of three primary colors, but in reality, there is a color that cannot be reproduced even with the three primary colors because negative energy intensity cannot be output.

As a specific example, in order to match the color with monochromatic light of, for example, 500 nm, the energy of the red primary color light must be negative. That is, the range of colors that can be reproduced by actually mixing color lights differs depending on how the three primary colors are selected. When a certain set of primary colors is given, a range of colors that can be reproduced by mixing the primary colors is called a “color reproduction area (Color Gamut)” of the primary colors. That is, also in the color image display device, the color reproduction range is determined by the color development of the three primary colors themselves. For example, in a CRT display, the color reproduction range is largely determined by the color development of the phosphor.
As explained at the beginning, the conventional CRT, LCD, PD
The reason why the color reproduction range that can be displayed by P, LED, and the like is narrow is that the color reproduction of these three primary colors themselves is limited.

The color matching function has the following properties. First, the color matching functions [r], [g], [b] (usually displayed with a bar, but for convenience here are displayed with square brackets and displayed as [r]) are arbitrary colored light. S is a weighting function for each wavelength for obtaining the intensities r, g, and b from the color light S itself when adjusting the intensities of the given three primary colors R, B, and G. That is, the color light having the spectral energy of S is the three primary color lights R, B, and G, and the expression S≡r
Assuming that the colors are equalized in the form of R + gG + bB (≡ is a relation of equal colors), r = S · [r], g = S · [g], b
= S · [b]. Colors that people see the same color are the same 3
It can be seen that the image signal for displaying the image while maintaining the metamerism needs to have the sensitivity of the color matching function so that the color is measured by the primary color values. This principle is actually used also in a color image display device such as a color television. The color television adjusts the amount of the electron beam applied to the phosphors of the three primary colors of red, green, and blue, and makes the color light S equal in color. Then, the intensity is measured by a television camera having a photosensitive element as an image pickup element such as a CCD having a color filter having three sensitivities approximating the respective color matching functions.

Although a detailed description is omitted, this color matching function is a linear conversion of the sensitivity of the three types of cones of the human retina, and the color matching functions have a linear conversion relationship. Therefore, it can be said that all the color matching functions can be transferred by a linear transformation. In order to perform color matching with the three primary color lights, an image signal must be generated with the sensitivity of the color matching function. Therefore, the condition for generating the image signal must be a linear conversion of the color matching function. This is called "router condition". It can be said that all the color lights can be color-matched by three independent color lights S. However, this is because the image signal is formed by any three independent spectral sensors regardless of the spectral distribution, and the result can be linearly converted. In order to generate an image signal that does not always provide a correct image display but accurate color reproduction, it is necessary to use one of the color matching functions.
One must do. If the spectral sensitivity of the image signal generation sensor does not have a color matching function, a correct image signal cannot be obtained by linear conversion. The value (r, g, b) of the obtained image signal is an intensity for equalizing the color light with the three primary colors R, G, B corresponding to the color matching function. The fact that the spectrum of the sensor is a color matching function is a condition for realizing metamerism,
If this is not the case, light that looks different to the human eye may be measured to the same color or vice versa. Furthermore, it can be said that the tristimulus values are linear transformations of the tristimulus values for the three cones. In the above sense, 3
It can be said that the stimulus values are shifted by linear transformation, but the condition is that the three stimulus values are correctly sensed by the color matching function. Therefore, the laser oscillator 13 of each wavelength for forming an image
And the image signal for driving the same must have the same color matching function. Therefore, an accurate color reproduction by the auxiliary laser oscillator 13G ₂ is the oscillation wavelength 50
The wavelength of 0 nm needs to be sensed by the sensor.

As described above, since the tristimulus values are shifted by a linear transformation, an arbitrary set of three primary colors can be determined to measure the color, and the tristimulus values can be measured by the color matching function determined thereby. However, it is convenient to use a standard color matching function for the sake of convenience in order to quantitatively express the color.
° The XYZ system of the field of view is S as the CIE-1931 XYZ system.
standard Colorimetric Obse
rver is determined and used. Here, this CI
The description will be made using the E-1931XYZ system.

The color matching functions [x], [y], [z] (usually displayed with a bar, but here are displayed with square brackets for convenience, such as [x]) are described above. [R],
[G] and [b] are linearly transformed. For convenience of calculation, each color matching function has a positive value over all wavelength bands.
[Y], one of the color matching functions, matches the illuminance function of the eye,
The relative magnitudes of [x], [y], and [z] are as follows. When the equal-energy white is measured at this sensitivity, the tristimulus values ([X], [Y], [Z]) are plotted on the graph. [X] = [Y] = [Z] so that the area under the curve is constant. Because of this property, the three primary colors X, Y, and Z corresponding to this color matching function are color lights that do not actually exist. CI using color matching functions [x], [y], [z]
According to the E-1931XYZ system, the color of the color light S is [X]
= S · [x], [Y] = S · [y], [Z] = S ·
It is represented by the tristimulus value of [z].

When it is desired to express the color light S by brightness and color components, it is also expressed by luminance Y and chromaticity (x, y).
The chromaticity (x, y) is defined by the following equation. x = [X] / ([X] + [Y] + [Z]) y = [Y] / ([X] + [Y] + [Z]) The chromaticity has the same ratio of energy at each wavelength. A chromaticity diagram is often used to indicate a color reproduction range in a certain mixed color system even if it changes. Here, FIG.
FIG. 9 is a diagram illustrating a CIE chromaticity diagram using XYZ chromaticity coordinates according to Z8701 (a color display method using an XYZ color system).

Further, color matching functions [x], [y], [z]
Is a tristimulus value that matches a single light color from its definition,
The chromaticities x (λ) and y (λ) of a single light color are x (λ) = [x] (λ) / ([x] (λ) + [y]
(Λ) + [z] (λ)) y (λ) = [y] (λ) / ([x] (λ) + [y]
(Λ) + [z] (λ)).

In FIG. 3, the chromaticity x of this single light color
When (λ) and y (λ) are drawn on the chromaticity diagram, a substantially horseshoe-shaped curve is drawn as shown by SP in FIG. This curve is called a spectrum locus SP (spectral locus),
The spectrum locus SP and the inside of the figure connecting both ends with line segments are the range of colors existing in the world. This is because the chromaticities x (λ) and y (λ) of the single light color are on the spectrum locus SP, and all colors other than the single light color are obtained by mixing the single light colors. This is because the chromaticities x (λ) and y (λ) of the mixed colors exist on a straight line connecting the chromaticities of the two colors.

FIG. 4 is a diagram showing the color gamut of a conventional image display device in this CIE chromaticity diagram ("Advanced technology of display", 1998).
(September 25, Chitani Tani, Kyoritsu Shuppan, pp. 183). LCD (Liquid Crystal Display), CRT
(Cathode ray tube), NTSC color television, PDP
(Plasma display panel) and an image display device using an LED (light emitting diode) each have a limit on the wavelength of the color of the luminous body, which is the three primary colors, and because it is not a single wavelength, color turbidity occurs, and the color reproduction range Was narrow. Compared with these, an image display device using an LS (laser scanner display) has a laser oscillator that emits three primary colors capable of reproducing a single wavelength and pure color without turbidity. Due to the fact that laser light can be oscillated, a much wider color display area can be achieved as compared with image display devices of other types, such as a triangle shown by LS in FIG. It became so.

FIG. 5 is a diagram showing the color gamut of the projection display apparatus 1 of the present embodiment in the CIE chromaticity diagram. Conventionally, as shown in FIG. 4, no matter which method is used, color mixing is performed using three primary colors, and the position of the triangle is determined in the horseshoe shape drawn by the spectrum trajectory SP. Also could not cover this spectrum locus SP. In particular, the conventional 3
The challenge was to expand the limits of primary color development, and was not a problem at all until eliminating visible light wavelengths that could not be reproduced. Under these circumstances, the development of various types of lasers including semiconductor lasers has greatly increased the types of oscillation wavelengths of laser oscillators, and laser scanner displays have been able to perform high-speed and high-precision scanning. A projection display device using a laser oscillator capable of oscillating a wavelength has become possible. However, in the case of using the conventional three primary colors, there are areas of colors that cannot be reproduced, and natural colors cannot be reproduced because of the areas of colors that cannot be reproduced. For example, the green of the trees in the fresh green season,
Although it is a color close to a pure color with a wavelength of around 500 nm, such a transparent green having a large saturation cannot be reproduced by any conventional method. In the projection display device 1 of the present embodiment, the color in the range of the quadrangular shape as shown in FIG. 5 is reproduced by using the fourth color of the auxiliary laser light for the color mixture, and the color reproduction range is expanded. , Enabling natural color reproduction.

In this embodiment, only one auxiliary laser beam is used and the image signal has four colors. However, the use of a plurality of auxiliary lasers makes it possible to expand the color reproduction range. Needless to say.

Here, generation of an image signal suitable for the projection display device 1 will be described. The image signal is a CCD (Charge Couple) (not shown) that generates a video signal.
dDevice) is generated using a video camera. According to the above-described metamerism, it is desirable to use a sensor and a luminous body having the same wavelength for color measurement and reproduction. It is necessary to use four colors according to the oscillator 13. Here, FIG.
FIG. 3 is a diagram schematically showing color filters arranged on a CCD for image reading. As shown in FIG. 6, the laser beam L oscillated by the laser oscillator 13
Red filter FR, green filter FG ₁ , and blue filter F, which are four filters corresponding to the wavelength of B
B, auxiliary filters FG ₂ (hereinafter referred to as filters F) are arranged in a matrix. Through this filter F, a signal corresponding to each laser oscillator 13 is generated.

Hereinafter, the filter F will be described in detail. FIG. 7 is a graph GFR showing the spectrum of the wavelength transmitted by the red filter FR, and a graph G13 showing the oscillation spectrum of the red laser oscillator 13R shown for comparison.
It is a figure showing R. As can be seen from this graph, in order to generate a red image signal as described above, a red filter FR is applied to a CCD so as to correspond to the sensor and red light is recorded as an image signal, and light of other wavelengths is recorded. Is cut. However, the reason why the width of the input wavelength is made wider than the wavelength output from the laser oscillator 13R is to secure the light quantity at the time of signal formation. This filter FR
Can be a broadband filter, so that a dye filter that is easy to manufacture and has low cost can be used. In addition,
Light rays with wavelengths longer than 780 nm are not visible light,
In order to correct the infrared sensitivity of the CCD, an infrared cut filter such as CM-500 is installed in advance.

[0050] Figure 8 is a graph GFG ₀ showing the spectrum of a wavelength transmission of conventional green filter FG _0, it is a diagram showing a graph G13G ₁ representing the oscillation spectrum of the green laser oscillator 13G ₁ shown for comparison. In conventional green filter, since narrowband filter is not required, such as in the auxiliary filter FG ₂ of the present embodiment as described below, it is possible to use the same broadband filter and a red filter FR. Note that the conventional green laser oscillator is the green laser oscillator 1 of the present embodiment.
To indicate 3G ₁ identical oscillation wavelength and a conventional green laser oscillator is also described as a 13G _1.

FIG. 9 shows a blue filter F of this embodiment.
A graph GFB showing the spectrum of the wavelength transmitted by B;
It is a figure showing graph G13B showing the oscillation spectrum of blue laser oscillator 13B shown for comparison. In this case, and a red filter FR above, to input the image signal in the same wide-band filter and a conventional green filter FG _0.

[0052] Figure 10 is a diagram showing a graph GFG ₂ showing a spectrum of wavelengths transmitted in this embodiment, the graph G13G ₂ representing the oscillation spectrum of the auxiliary laser oscillator 13G ₂ shown for comparison. Auxiliary laser oscillator 13G ₂ for oscillating a wavelength of 500nm, in broadband filter, such as a conventional green filter FG ₀ as described above, since close to the wavelength of the green laser oscillator 13G _1, narrow narrowband wavelength ranges transmitted through It becomes necessary to use a filter. Therefore, as shown in GFG ₂ in FIG. 10, using filters FG ₂ narrowband. Since this narrow band filter cannot be manufactured with a dye filter, transmitted light is selected using an interference filter.

Meanwhile, FIG. 11 is a graph GFG ₁ showing the spectrum of wavelengths transmitted through the green filter FG ₁ of the present embodiment, green laser oscillator 13G shown for comparison
It is a diagram showing a graph G13G ₁ representing _one of the oscillation spectrum. In this case, so as not to overlap with the oscillation wavelength of the auxiliary laser oscillator 13G _2, below around 510nm is using filters FG ₁ which does not pass through.

FIG. 12 shows conventional filters FR and F.
Graph G showing the spectrum of the wavelengths transmitted by G ₀ and FB.
_FR, is a diagram illustrating the GFG 0, GFB, the laser oscillator 13R shown for _comparison, the graph represents the oscillation spectrum of the 13G _1, 13B G13R, the G13G 1, G13B. As shown here, conventionally, since the wavelengths of the three primary colors are far apart, it was possible to use a wide-band filter and transmit a wide range of wavelengths.

FIG. 13 shows a filter F of this embodiment.
_{R, FG 1,} FG _2, graphs showing the spectrum of the transmitted wavelength of FB _GFR, and GFG _1, GFG _{2, GFB,}
Laser oscillator 13R shown for comparison, _13G 1, 13
Graph representing the oscillation spectrum of G _2, 13B G13R,
G13G _1, a diagram illustrating a G13G _2, G13B. As shown in the figure, the oscillation wavelength G13G ₁ green laser oscillator 13G ₁ and the auxiliary laser oscillator 13G _2, G13G ₂ are close, by using a filter of a narrow band, as described above, the auxiliary laser oscillator 13G ₂ can be obtained.

CCD equipped with the filter F as described above
A video camera generates image information into a video signal.
This method is the same as the generation of a well-known video signal except that a four-color signal is obtained by adding an auxiliary signal for an auxiliary laser beam in addition to the RGB signal.

Next, the operation of displaying an image on the projection display device 1 based on the image signal generated as described above will be described with reference to FIGS. The image information generated as described above is input as a video signal via the interface 48 from a CCD video camera or a video deck for reproducing a tape or the like on which the image information is recorded.
The input video signal is input to an image input unit 47 as RG
B and an auxiliary signal. Based on the separation signal, the control unit 40 sends a control signal of the polygon mirror to the polygon mirror control unit 16 and sends a control signal to the laser oscillator control unit 15 so as to synchronize with the rotation of the polygon mirrors 17 and 18. oscillator control unit 15, the laser oscillator 13R, _13G 1, 13
A drive signal is sent to G ₂ and 13B.

The laser beams LB (R), LB (G ₁ ), LB (B), LB (G ₂ ) thus emitted
Are combined into one optical path by the laser combiner 14,
The main scanning polygon mirror 17 scans the screen 50 in the horizontal direction X. However, the main scanning is performed on the screen 5
In consideration of the error in the projection direction to 0, the laser beam LB is started from slightly above in FIG. 2 and is incident on the sub-scanning beam sensor 20 provided near the scanning start position direction of the screen 50. 20 to control unit 40
The modulation of the laser beam LB is not started until the SOS signal is sent to the controller. S from the sub-scanning beam sensor 20
When the OS signal is present and the laser beam LB is incident on the main scanning beam sensor 19, the SOS signal is transmitted from the main scanning beam sensor 19 to the control unit 40, and the control unit 4
0 starts modulation of each laser oscillator 13 based on the image signal so that an image is projected from a predetermined position on the screen 50 based on the SOS signal. When one main scan is completed as described above, the emission direction of the laser beam LB moves to the next main scan line by the sub-scanning polygon mirror 18, so that the SO beam transmitted by the main scanning beam sensor 19 is returned again.
The main scanning of the next row is performed by the S signal.

In this way, the main scanning is performed 525 times on the screen 50 by the laser beam LB, and one screen is displayed every 1/30 second. By performing high-speed and fine scanning in this manner, a full-color screen for expressing colors that could not be expressed conventionally can be continuously displayed with high luminance, and a smooth moving image can be displayed.

In this case, the auxiliary laser oscillator 13G
The oscillation wavelength of No. ₂ is in a relationship of a substantially complementary color to the oscillation wavelength of the red laser oscillator 13R. As described above, by emitting an auxiliary laser oscillator 13G ₂ 500 nm laser beam LB (G
_In the case where the red laser oscillator 13R emits light even when ₂ ) is oscillated, it is determined on the straight line connecting two vertexes indicating each of the squares shown in FIG. Color. Also, there must be emitting auxiliary laser oscillator 13G ₂ As can be seen from FIG. 5 is a color of a region of the left part of the broken line in FIG. 5, only if the red laser oscillator 13R is hardly emission Can be Conversely, if when the red laser oscillator 13R is emitting light low means for emitting auxiliary laser oscillator 13G _2. Therefore, in the present embodiment, on condition that the red laser oscillator 13R does not emit light, and controls so as to emit the auxiliary laser oscillator 13G _2.
By doing so, unnecessary auxiliary laser oscillator 13G
₂ are excluded. Conversely, the auxiliary laser oscillator 13
May be controlled so as to cut the emission of the red laser oscillator 13R if the image signal to emit G ₂ is input. Also in this case, when a color having a wavelength of about 500 nm is displayed, if the red laser oscillator 13 </ b> R emits light, color reproduction becomes turbid, and it becomes difficult to reproduce a clear color of a wavelength of about 500 nm. Moreover, in this way, the auxiliary laser oscillator 13G _2, the main laser oscillator 1
The exclusive use of any of the 3Ms simplifies control. And power saving can also be measured. The same applies to a case where there are a plurality of auxiliary laser oscillators, and the same advantage can be obtained by simultaneously lighting up to three lamps.

Since the projection display device 1 has the above-described configuration and operation, it is possible to reproduce colors and the like that could not be reproduced conventionally, a wide range of colors that can be reproduced, and beautiful colors faithful to more natural colors. There is an effect that a color image can be displayed.

Although the present invention has been described based on one embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Can be implemented. For example, a semiconductor laser and an SHG (nonlinear optical element) may be used as the laser oscillator. Furthermore, a semiconductor laser array that emits a plurality of laser beams from a single package may be used.

[0063]

As is apparent from the above description, claim 1
According to the projection display device of the invention, the three types of main laser light having the wavelengths of the three additive primary colors and the auxiliary laser light having a wavelength different from the wavelengths of the three primary colors are oscillated based on the image signal. An auxiliary laser beam, comprising: a laser oscillator; and a laser scanner that integrally scans laser beams of respective wavelengths emitted from the laser oscillator and projects a desired image on a predetermined screen. The use of the light of the color (3) has an effect that a color that cannot be reproduced by the light of the wavelengths of the three primary colors can be reproduced. Therefore, there is an effect that color reproduction closer to a natural color can be performed.

In the projection display device according to the second aspect of the present invention,
In addition to the effect of the projection display device according to claim 1, the auxiliary laser beam is oscillated only when at least one type of main laser beam among the main laser beams is not oscillated. There is an effect that control for oscillating laser light only when necessary can be performed.

In the projection display device according to the third aspect of the present invention,
In addition to the effect of the projection display device according to claim 1 or claim 2, the auxiliary laser beam is set at approximately 500 nm, and therefore, cannot be emitted particularly with the conventional three primary colors. There is an effect that colors near 500 nm can be reproduced.

In the projection display apparatus according to the fourth aspect of the present invention,
In addition to the effects of the projection display device according to any one of claims 1 to 3, the image signal corresponds to an image signal corresponding to the wavelength of the three primary colors and a wavelength different from the wavelength of the three primary colors. Since the image display apparatus is characterized by being generated by an image signal, a projection display device including a laser oscillator that oscillates auxiliary laser light has an effect that suitable control can be performed using the image signal. for that reason,
Further, there is an effect that color reproducibility can be improved.

[Brief description of the drawings]

FIG. 1 is a projection display device 1 according to an embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating the main configuration of FIG.

FIG. 2 is a schematic diagram illustrating a laser scanner unit 10;

[3] x, the y, it illustrates the C IE chromaticity diagram using the XYZ system chromaticity coordinates by JIS Z 8701 (a color display method according to the XYZ color system).

FIG. 4 is a diagram showing a color gamut of a conventional image display device in a CIE chromaticity diagram.

FIG. 5 is a diagram showing a color gamut of the projection display device 1 according to the present embodiment in the CIE chromaticity diagram.

FIG. 6 is a diagram schematically showing color filters arranged on a CCD for image reading.

FIG. 7 is a diagram showing a graph GFR showing a spectrum of a wavelength transmitted by a red filter FR of the present embodiment and a graph G13R showing an oscillation spectrum of a red laser oscillator 13R shown for comparison.

[8] a graph GFG ₀ showing the spectrum of a wavelength transmission of conventional green filter FG _0, is a diagram showing a graph G13G ₁ representing the oscillation spectrum of the green laser oscillator 13G ₁ shown for comparison.

FIG. 9 is a diagram showing a graph GFB showing a spectrum of a wavelength transmitted by the blue filter FB of the present embodiment and a graph G13B showing an oscillation spectrum of a blue laser oscillator 13B shown for comparison.

A graph GFG ₂ showing a spectrum of a wavelength transmission of Figure 10 the auxiliary filter FG ₂ of the present embodiment, a diagram showing a graph G13G ₂ representing the oscillation spectrum of the auxiliary laser oscillator 13G ₂ shown for comparison.

A graph GFG ₁ showing the spectrum of wavelengths transmitted through the green filter FG ₁ in FIG. 11] This embodiment illustrates a graph G13G ₁ representing the oscillation spectrum of the green laser oscillator 13G ₁ shown for comparison.

FIG. 12 is a graph GFR, GFG ₀ , graph showing spectra of wavelengths transmitted by conventional filters FR, FG ₀ , FB.
GFB and laser oscillators 13R, 13R shown for comparison.
Graph representing the oscillation spectrum of the G _1, 13B G13R,
G13G _0, illustrates the G13B.

FIG. 13 shows filters FR, FG ₁ , F of the present embodiment.
G ₂ , a graph G showing the spectrum of the wavelength transmitted by FB
_{FR, GFG 1, GFG 2,} GFB and laser oscillator _13R shown for comparison, 13G _1, 13G 2, 13B graph represents the oscillation spectrum of the G13R, G13G _1, G
It is a diagram illustrating a 13G _2, G13B.

DESCRIPTION OF SYMBOLS 1 Projection display device 2 Main body 10 Laser scanner unit 11 Scanner 12 Scanner control unit 13 Laser oscillator 13R Red laser oscillator 13G ₁ Green laser oscillator 13B Blue laser oscillator 13G ₂ Auxiliary laser oscillator 14 Laser beam synthesizer 14A First Laser beam combiner 14B Second laser beam combiner 14C Third laser beam combiner 15 Laser oscillator controller 16 Polygon mirror controller 17 Main scanning polygon mirror 18 Sub scanning polygon mirror 19 Main scanning beam sensor 20 Sub scanning beam sensor 40 Control part 47 image input unit 48 interface 50 screen 51 f [theta] lens LB laser beam LB (R) red laser beam LB _(G 1) a green laser beam LB (B) blue laser beam LB _(G 2) auxiliary laser Over-time

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

FIG. 8

Claims (4)

[Claims] 1. A laser oscillator that oscillates three types of main laser light having wavelengths of three primary colors of an additive color mixture and auxiliary laser light having wavelengths different from the wavelengths of the three primary colors, based on an image signal, A projection display device, comprising: a laser scanner that integrally scans laser light of each wavelength emitted from an oscillator and projects a desired image on a predetermined screen. 2. The projection display device according to claim 1, wherein the auxiliary laser light is oscillated only when at least one type of main laser light among the main laser lights is not oscillated. 3. The projection display device according to claim 1, wherein the auxiliary laser beam is set to approximately 500 nm. 4. The image signal according to claim 1, wherein the image signal is generated by an image signal corresponding to the wavelength of the three primary colors and an image signal corresponding to a wavelength different from the wavelength of the three primary colors. The projection display device according to claim 3.