JP2000197069A - Projection display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the black level of a background screen even in a bright surrounding condition and to display the color image of high contrast and high visibility by projecting prescribed three-wavelength laser beams used as the three primary colors of additive color mixture to filters, corresponding to respective wavelengths and performing scanning. SOLUTION: A transmission type screen 50 is irradiated with laser beams LB of red, green and blue constitution and a user U views images plotted by the laser beams LB via a transmission type diffusing plate 53 and a filter 52. On the main body side of the transmission type diffusing plate 53, sectioned finely red, green and blue filters 52 are disposed in a striped shape. In this case, for the laser beams LB of three colors abutted to the red filter 52R, only a red laser beam LBR reaches the user U, and the other colors hardly pass through. Also, it is similar to the case of other color filters, the filters 52 form a black-looking visually dark background, and while the black level is low, the user U views sharp images of the laser beams LB.

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 displays an image on a screen by projecting a laser beam and scanning the same. It relates to an enhanced projection display device.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed for displaying a color image, and a laser display is one of them. For example, Japanese Patent Application Laid-Open No. 1-245780
JP, JP-A-3-65816, JP-A-4-18
The laser beams of red (red (hereinafter, R)), green (green (hereinafter, G)), and blue (blue (hereinafter, B)), which are three primary colors of additive color mixture as described in Japanese Patent No. 1289, are respectively used as laser oscillators. Oscillate, and combine the optical paths of these outputted laser beams into one, and combine the combined laser beams onto the same point on a screen made of a scattering plate such as white to perform simultaneous additive color mixing. ,
A projection display device that displays a color image or the like on a screen by two-dimensionally scanning this at high speed has been proposed. In such a projection display device, even a small device can display a color image on a large screen by using a laser beam having a large power density.

[0003]

However, in a situation where the surroundings are bright and external light is incident on the screen, even if the laser light has a large power density, the reflected laser light has a high reflectivity because it is reflected. It is necessary to use a screen, and the screen cannot be blackened.
The background screen is brightened by the rays from the surroundings,
In some cases, black portions of the screen could not be displayed as black. In particular, in a screen using an open-type reflection / scattering plate or the like, external light was easily reflected and a high contrast could not be obtained. Therefore, when an image is projected in a bright place, there is a problem that only a low-contrast, low-visibility image that is not blackened can be displayed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and provides a projection display device capable of displaying a color image with high contrast and high visibility by lowering the black level of a background screen even in a bright surrounding. With the goal.

[0005]

To achieve this object, a projection display apparatus according to the first aspect of the present invention comprises: A laser modulation circuit for modulating the output of the laser oscillator corresponding to each of the three wavelengths of image signals, and irradiating a laser beam of each wavelength whose output has been modulated by the laser modulation circuit. A laser scanner that scans the screen two-dimensionally, and a projection surface on which the laser light is projected, and a filter that selectively transmits the three wavelengths of laser light, respectively, are provided in parallel with each other corresponding to the main scanning line. A screen arranged side by side in a band-shaped area, wherein the laser scanner projects and scans the three wavelength laser beams onto filters corresponding to the respective wavelengths. Characterized in that it is configured.

[0006] In the projection display device according to this configuration, the screen can selectively reflect only the wavelength of the laser light to be projected. Therefore, the background screen is not brightened by the reflection or transmission of light having a wavelength unrelated to image formation, so that the contrast of the image does not decrease. be able to.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, a light absorber for absorbing light is provided between the filters. It is characterized by having.

[0008] In the projection display device according to this configuration, the black density of the screen can be further increased by providing the screen with the light absorber. Therefore, the contrast of the image can be increased, and the visibility can be further improved.

[0009] 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 laser modulation circuit modulates the three wavelength lasers in synchronization with each other so as to scan at a time corresponding to a main scanning period of an image signal. In the screen, the filters corresponding to the three wavelengths are 、 of the arrangement pitch of the main scanning lines.
And the laser scanner is configured to simultaneously scan laser beams of three wavelengths modulated by the laser modulation circuit at a time corresponding to a main scanning cycle of an image signal. It is characterized by.

[0010] In the projection display apparatus according to this configuration, the filters corresponding to the light of three wavelengths are arranged side by side in the width of one main scan, and the laser light corresponding to the transmitted wavelength is irradiated. Therefore, the contrast can be increased without transmitting light of an unnecessary wavelength, and an image with high resolution can be displayed.

[0011] In the projection display device according to the fourth aspect of the invention,
A laser oscillator that oscillates laser light of three predetermined wavelengths used as three primary colors of additive color mixing; and a laser modulation that modulates the output of the laser oscillator corresponding to each wavelength in response to each of the three wavelength image signals. A laser scanner for combining a light path of laser light of each wavelength, the output of which is modulated by the laser modulation circuit, and two-dimensionally scanning a screen while irradiating the laser light on the same light path; and projecting the laser light. A screen provided with a filter for selectively transmitting any of the three wavelengths of laser light.

In the projection display device according to this configuration, since a filter provided on the screen does not transmit light other than the laser light irradiated for image formation, an image with high contrast can be obtained. Further, since the filter transmits laser light of any wavelength, it is not necessary to adjust the positions of the screen and the laser scanner.

According to a fifth aspect of the present invention, in addition to the configuration of the projection display device according to any one of the first, second and fourth aspects, the laser modulation circuit comprises
A laser oscillator having a wavelength is modulated so as to sequentially scan at a time of 1/3 of a time corresponding to a main scanning cycle of an image signal, and the laser scanner is driven by the laser modulation circuit.
The laser beam of the wavelength is sequentially scanned in a time of 1/3 of a time corresponding to the main scanning cycle of the image signal.

In the projection display apparatus according to this configuration, since the laser oscillators of three wavelengths are not driven at the same time, it is not necessary to drive the laser oscillators at once with a large current.

According to a sixth aspect of the present invention, there is provided a projection display apparatus comprising: a laser oscillator for oscillating laser light of three wavelengths used as three primary colors of additive color mixing; A laser modulation circuit for modulating the output of a laser oscillator, a laser scanner for two-dimensionally scanning a screen while irradiating three wavelength laser light whose output has been modulated by the laser modulation circuit, Observation glasses provided with a filter that selectively transmits only light near the wavelength.

In the projection display apparatus according to this configuration, the filter that transmits only a predetermined wavelength is used as observation glasses.
Since an image is observed, an image displayed on a normal screen can be viewed with high contrast even in a bright environment without using a special screen. Also, there is no need to adjust the positional relationship between the screen and the scanner.

[0017]

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, an outline of the configuration of the projection display device 1 is shown in FIG.
This will be described with reference to FIG.

As shown in FIG. 1, a 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 apparatus 1 receives a signal 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, A drive signal is generated by the control unit 15, and a red laser oscillator 13R, a green laser oscillator 13G, and a blue laser oscillator 13B (see FIG. 3, hereinafter collectively referred to as a laser oscillator 13) provided in the laser scanner unit 10 are oscillated. Each of the red laser beam LB (R), the green laser beam LB (G), and the blue laser beam LB (B) emits and irradiates a laser beam LB. The laser beam LB is a main scanning polygon mirror (rotating polygon mirror). 17 and sub-scanning polygon mirror 1
8 (hereinafter collectively referred to as polygon mirrors 17 and 18)
Is projected onto the screen 50 while being scanned two-dimensionally to form an image.

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.

FIG. 2A is a view showing a state in the projection display device 1.
FIG. 3 is a diagram schematically illustrating a part of the structure of a screen 50.
According to FIG. 2A, the screen 5 of the present embodiment
0 will be explained. First, the projection display device 1 of the present embodiment
Is a transmission type screen, and the main body 2 (not shown) is disposed at the upper right in FIG. 2A (see FIG. 1). Here, for convenience of explanation, LB (R) and LB (R) are used instead of light having a complex spectrum.
Assume that a laser beam LB composed of (G) and LB (B) is emitted from the upper right to the lower left. Then, a viewer of the image (hereinafter, referred to as a user U) views the image drawn by the laser beam LB from the transmission type diffusion plate 53 through the filter 52 from the lower left in the figure. On the main body 2 side of the transmission type diffusion plate 53, a finely divided red filter 52 is provided.
A large number of R, green filters 52G, and blue filters 52B (hereinafter, referred to as filters 52) are arranged in stripes. As the filter 52, a primary color dye filter is used. The dye filter can be manufactured in a printing process, can be easily realized by printing in a stripe shape on the screen 50, and is more cost-effective than the interference filter. Although the figure is deformed and drawn thicker for the sake of explanation, the actual filter 52 is an extremely thin film printed on the transmission type diffusion plate 53 as described above. Has a negligible thickness.

FIG. 9 is a graph showing the oscillation spectrum of the laser oscillator 13 and the spectral characteristics of the transmitted light FB of the filter 52. The vertical axis indicates the light intensity at that wavelength in the case of the laser oscillator 13 and the transmittance at that wavelength in the case of the filter 52. The horizontal axis represents the wavelength λ to be emitted or transmitted, and the unit is nm (nanometer).

First, FIG. 9A shows a red laser oscillator 1.
3 shows an oscillation spectrum of 3R and a spectral characteristic of light transmitted through the red filter 52R. As shown in FIG. 9A, the oscillation spectrum of the red laser oscillator 13R is approximately 650 n
In the vicinity of m, a spectrum in a very narrow range with a substantially simple vibration is shown. With respect to the oscillation spectrum of the red laser oscillator 13R, the transmitted light of the red filter 52R transmits light of a long wavelength including the oscillation spectrum of the red laser oscillator 13R, and absorbs light of wavelengths of other colors. Resulting in. The wavelength exceeding 780 nm is not visible light,
Further, since a wavelength of about 730 nm or more can be sensuously ignored, it has the same effect as not transmitting the light to the user, and does not make the screen 50 feel bright. On the other hand, from the red laser oscillator 13R to the red filter 52R
The laser beam LB emitted in the above is transmitted efficiently without substantially attenuating the light amount. That is, it can be seen that light of a visible wavelength other than the red laser beam LB (R) is not transmitted.

However, in the case of the laser beam LB having an extremely narrow spectrum width, the amount of light is extremely small as compared with sunlight SB or the like. However, when compared in a specific range of wavelengths, the laser beam LB has an extremely narrow spectrum range. Since the power is concentrated on an extremely small area on the screen 50, the amount of light per unit is sufficiently large as compared with sunlight SB or the like, and the light becomes sufficiently strong to display an image. Therefore, the user can see the vivid red pure color of the red laser beam LB (R) in a tight background with a high black level.

Next, FIG. 9B shows the green laser oscillator 13.
9 shows an oscillation spectrum of G and a spectral characteristic of light transmitted through the green filter 52G. Also in this case, similarly to the case of the above-described red laser oscillator 13R and red filter 52R, the green filter 52G transmits only light having a wavelength near 520 nm which is the oscillation wavelength of the green laser oscillator 13G. Therefore, unlike the red filter 52R, not only light having a shorter wavelength but also light having a longer wavelength is cut off. Also in this case, since the light other than the green light is absorbed and not transmitted, the total amount of transmitted light is reduced, and the amount of light is reduced, resulting in a sensually blackish color tone and a tight background. The green laser beam LB (G) of the green laser is
Since the light is transmitted without being attenuated, a bright green image is drawn on the transmission diffusion plate 53.

FIG. 9C shows a blue laser oscillator 13B.
And the spectral characteristics of light transmitted through the blue filter 52B. As shown in FIG. 9C, the blue laser oscillator 13B oscillates a blue laser beam LB (B) having a narrow band wavelength centered on 450 nm, and the blue filter 52B has a narrow range of wavelengths corresponding to this wavelength. This is a configuration in which only light is transmitted, and similarly to filters of other colors, since transmitted light is usually small, it is sensuously observed as dark.

FIG. 11 is a graph schematically showing the spectral distribution of sunlight SB. The graph shown by the solid line is a graph showing the spectrum of sunlight SB, and the graph G52B, G52G, G52R shown by the chain line is a graph showing the transmittance of each filter 52. Further, graphs FB (B), FB (G), F
B (R) indicates the light intensity of the transmitted light of the sunlight SB transmitted through the filters G52B, G52G, and G52R, respectively.
It can be seen from the graph of FIG. 11 that even if an extremely large amount of light including light beams of various spectra such as sunlight SB hits the main body 2 side of the red filter 52R, for example, it can be understood from the graph. The sunlight S
Most of the light amount of B is absorbed, and only a small amount of transmitted light FB (R) is transmitted therethrough. Further, the wavelength to be transmitted is only the wavelength of the red light, but similarly, the transmitted light FB of the green and blue filters 52G and 52B transmitted therethrough.
Is mixed with white light, but the total amount of transmitted light FB (R) is smaller than that of sunlight SB. Therefore, a user who is functionally located on the opposite side of the screen has a dark background. Is maintained. That is, it looks dark.

Returning to FIG. 2A again, as shown here, the red, green, and blue laser beams LB (R), LB hitting the red filter 52R.
(G) and LB (B) indicate that the red filter 52R is 650.
Since only light having a wavelength near nm is transmitted, light having a wavelength other than red is absorbed, and as a result,
Only the red laser beam LB (R) reaches. Further, in the portion of the other red filter 52R where the red laser beam LB (R) of the red laser oscillator 13R is not irradiated, the amount of red light passing therethrough is small and looks blackish in appearance. Similarly, for the other green and blue colors, only the green laser beam LB (G) and the blue laser beam LB (B) are transmitted, and the other light beams are hardly transmitted. Is translucent,
Because the filter 52 looks dark, the user U visually forms a dark background, and the user U can see an image by the bright laser beam LB while the black level is low (dark).

In the present embodiment, the projection display apparatus 1 uses the transmission screen 50, but this screen may be a reflection screen. Here, FIG. 2B is a diagram illustrating a first modified example including a screen 150 using the reflection type diffusion plate 54. As shown in FIG. 2B, light R, G, and B traveling toward the screen 150 are:
When the light strikes the red filter 152R, G and B are absorbed and attenuated. On the other hand, the red laser beam LB (R) composed of a red light beam enters the red filter 152R, strikes the reflection type diffusion plate 154 and is reflected. In FIG. 2B, the filter 152 is drawn thick for the sake of explanation. However, in actuality, as described above, the filter 152 is extremely thin and can be manufactured only by printing, and refraction is almost negligible. Therefore, the transmission type screen 50 is different from the transmission type screen 50 in that the light passes back and forth through the filter 152 before and after the reflection, but the basic configuration is the same as that of the structure for transmitting only light of a specific narrow band wavelength. Even if the surroundings are bright, most of the light that hits the screen 150 is absorbed, so that the screen becomes a background with a low black level, and the filter 15
The image formed by only the laser beam LB of the specific wavelength transmitted through 2 is visually perceived by the user U, and the user U can see the image drawn by the vivid laser beam LB on a black background screen even in a bright surrounding. it can.

FIG. 3 is a schematic diagram for explaining the laser scanner section 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 three-wavelength laser oscillator. An He-Ne laser is applied to the red laser oscillator 13R that emits red light, and an H-Ne laser is applied to the blue laser oscillator 13B that emits blue light.
An Ar laser is suitably used for the green laser oscillator 13G in which the e-Cd laser emits green light.

The laser beams LB (R), LB (G), L
B (B) is combined into a laser beam LB having one optical axis by a first laser beam combiner 14A and a second laser beam combiner 14B (hereinafter referred to as laser beam combiner 14). First, the red laser oscillator 13R and the green laser oscillator 13G are combined by the first laser beam combiner 14A. The first laser beam combiner 14A is composed of a dichroic mirror (wavelength selective reflector), and emits a red laser beam L emitted from a red laser oscillator 13R.
B (R) is transmitted, but the green laser beam LB (G) emitted from the green laser oscillator 13G is made of a material that reflects the light depending on the wavelength of the output light. Therefore, the red laser beam LB (R) and the green laser beam LB (G) respectively emitted from the red laser oscillator 13R and the green laser oscillator 13G disposed orthogonally to the first laser beam combiner 14A are converted into a red laser beam. Beam LB
(R) passes through the dichroic mirror and travels straight, and the green laser beam LB (G) is reflected by the dichroic mirror and its optical axis is deflected at a right angle. Is adjusted to have an optical axis of

Similarly, the second laser beam combiner 14B combines the red laser beam LB (R) and the green laser beam LB (G) with the blue laser beam LB (LB) emitted by the blue laser oscillator 13B. B) is synthesized, and the original input color can be reproduced. In addition, the composition of these three color laser beams LB may be a dichroic prism or a configuration in which light beams are combined by a prism using a difference in refractive index depending on the wavelength. May be combined into one optical path.

FIG. 6 shows a laser beam L of three colors.
FIG. 9 is a diagram showing a position where the light path of B is made to coincide and the light is irradiated on the screen 50. As shown in FIG. 6, the screen 50 of the projection display device 1 has filters 52 of three colors alternately arranged in the order of red, green, and blue in a stripe shape.
These red, green and blue filters 52R, 52G, 5
2B are arranged in a width d in which main scanning is performed once in three rows. In other words, the width of each filter 52 is 1
This indicates a width that is ３ of the width d that is main-scanned each time.

Laser beam L combined into one optical path
B is irradiated and scanned with a width corresponding to the width d of this one main scan. When the screen 50 is irradiated in one optical path by mixing the three color components as described above, the red, green, and blue filters 52R, 52G, and 52B are simultaneously irradiated as described in the description of the screen 50 described above. Even in this case, for example, since the component of the red laser beam LB (R) passes through only the red filter 52R, even if the component of the red laser beam LB (R) hits another color filter, the user U can convert the image of the red laser beam LB (R) to another color. There is no observation through the filter. Similarly, the green laser beam LB
(G), since the blue laser beam LB (B) transmits only the light that has hit the green filter 52 (G) and the blue filter 52 (B), the light of each color passes through the filter 52 of each color. As a result, it becomes light for forming an image. In this case, the filters 52 of three colors of red, green and blue are formed in the width d of one main scan and are very close to each other. Then, the light of the blue component is again subjected to side-by-side additive color mixing, and an image reproduced in the original color tone of the image information can be observed.

In the projection display apparatus 1 according to the present embodiment, the laser beams LB of three colors are combined into one optical path. Laser beam LB (R), L
The optical paths of B (G) and LB (B) can be adjusted.
Hereinafter, the three color laser beams LB (R) and LB
A second modification example in which scanning is performed with the optical paths of (G) and LB (B) separated will be described.

FIG. 7 shows a laser beam L of three colors.
FIG. 9 is a diagram showing a position where the optical path of B is shifted to irradiate the screen 50. As shown in FIG. 7, the screen 50 is
This is the same as that shown in FIG. 6 in which the filters 52 of three colors are alternately arranged in stripes in the order of red, green and blue. Accordingly, the red, green, and blue filters 52R, 52G, and 52B are arranged in three rows with a width d that is main-scanned at one time. The scanner 11 applies the laser beams LB (R), LB (G), and L to the three color filters 52R, 52G, and 52B in the optical paths separated into three colors.
B (B) is irradiated and scanned. In this case, the light flux of each laser beam LB is 1/3 of the width d of one main scan. in this case,
For example, the red laser beam LB (R) shown in FIG. 7 is irradiated only to the red filter 52R, so that there is little light that is unnecessarily absorbed by the filter 52.
The output efficiency of light for forming an image is good with respect to the output.

Next, the laser beam LB of the projection display device 1
Will be described with reference to FIGS. 1 and 3. 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 is a regular hexagonal prism having a height lower than the bottom surface as shown in FIG. 3, and is disposed at a position where a line whose rotation axis is horizontal and which is 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 oscillator LB provided in the scanner controller 12 and the polygon mirror controller are provided so that the laser beam LB reflected by the main scanning polygon mirror 17 is not projected out of a predetermined angle range. 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).
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 transmitted 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. 3 on the screen 50, and one line of images 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 below it 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 the 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 one-sided mirror). However, it is preferable to use a polygon mirror using a polygon mirror since there is no change in the angular velocity than using a galvanometer.

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

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) in one screen is reduced to 1/3.
The sub-scanning (vertical scanning) of 0 seconds is performed, and a smooth screen with little flicker can be projected.

Returning to FIG. 1, to continue the description, as described above, the scanner control unit 12 includes the laser oscillator control unit 15
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. 3).
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 has a storage means which is also a developing place for developing the image data.
As input data, a general RGB video signal is input via the interface 48. The input signal is not limited to this, and a signal of various types may be input.

Next, FIGS. 4A to 4C show a projection display device when the laser beams LB of three colors are irradiated on the same position on the screens 50 and 150 in the same optical path as shown in FIG. 1 shows an image signal timing chart. The vertical axis is
The intensity V of the input signal and the intensity VR, V of the separation signal of each color
G and VB are schematically shown, the horizontal axis represents the passage of time, T represents the time of the horizontal scanning cycle of the input signal,
Δt indicates the time of the horizontal scanning period actually scanned by the projection display device 1. As shown in FIG. 4, when irradiating the same position, the red laser oscillator 13R, the green laser oscillator 13G, and the blue laser oscillator 13B are sequentially switched to be sequentially turned on at every Δt of 時間 of the time of each horizontal scanning cycle T. Let it.

FIG. 4A shows image data in which the input three color components are combined. This image data is input to the image input unit 47 once. FIG. 4B is a diagram illustrating a separated signal obtained by separating the R, G, and B signals from the input signal illustrated in FIG. As shown in FIG. 4B, the signals are separated into three color separation signals. Next, FIG. 4C is a diagram showing a modulation signal for modulating the output of the laser oscillator 13 based on the separation signal shown in FIG. 4B. Then, the separation signal of the horizontal scanning period T is converted into a laser modulation signal. At this time, the length of the modulation signal which is a drive signal of the laser oscillator 13 is changed to an image signal as shown in FIG. R
It is assumed that the GB separation signal is a signal whose time is reduced to 1/3. Therefore, the laser emission time by each laser oscillator 13 is emitted and scanned by a length of 1/3 of the horizontal scanning period T of the original image signal. Then, scanning is performed so as to have an image length T by scanning of three colors of RGB. As a result, the color image data of the image data is reproduced on the screens 50 and 150 by successive additive color mixing. As described above, since the laser oscillator 13 is not simultaneously turned on by sequentially scanning, it is possible to reduce the power without outputting a large output at a time.

On the other hand, FIGS. 5A and 5B show three color laser beams LB as shown in FIG.
In the case where the scanning is set so that the optical path is shifted by 1/3 of the width d of one main scanning on the zero, the scanning is performed.
5 shows an image signal timing chart in the case of lighting simultaneously in each horizontal scanning cycle T.

FIG. 5A shows image data in which the input three color components are combined. This image data is input to the image input unit 47 once. FIG. 5B is a diagram showing a separated signal obtained by separating the R, G, and B signals from the input signal shown in FIG. 5A. As shown in FIG. 5B, the signals are separated into three color separation signals. FIG. 5C is a diagram illustrating a modulation signal that modulates the output of the laser oscillator 13 based on the separation signal illustrated in FIG. Then, the separation signal of the horizontal scanning period T is converted into a laser modulation signal. At this time, the horizontal scanning period T of the modulation signal which is the drive signal of the laser oscillator 13 is changed as shown in FIG. The image signal R
The GB separation signal is used as a modulation signal in the horizontal scanning period T as it is. Then, R synchronized from the laser oscillator controller 15
The GB modulated signal is sent to each laser oscillator 13 at the same time, and is emitted and scanned at the same time. Then, scanning is performed so that the image length becomes T by simultaneous scanning of three colors of RGB. As a result, the color image data of the image data is reproduced on the screens 50 and 150 by the juxtaposed additive color mixture.

As shown in FIG. 6, laser beams LB of three colors are used.
May be simultaneously illuminated in the horizontal scanning period T according to the image signal timing chart as shown in FIG. Conversely, as shown in FIG. 7, the screen 50, the screen 50,
Even in the case of irradiating a different position on 150, it may be configured to turn on the light sequentially for one-third of the horizontal scanning period T according to an image timing chart as shown in FIG.

Further, the configuration is the same as that of the projection display apparatus 1 of the present embodiment, except that the entire screen is covered by a three-wavelength transmission filter 55 (not shown) instead of having the three-color filter 52. You can also. In such a case, an image can be displayed by projecting and scanning the laser beam LB according to an image signal timing chart as shown in FIG. 4 or FIG. Here, FIG.
0 shows the spectrum of the transmission wavelength of the three-wavelength transmission filter 55. By using such a filter, the selectivity of the wavelength is reduced, which is slightly disadvantageous in that the contrast of the image is increased. However, the effect of eliminating the need to align the positions of the laser beam LB and the screens 50 and 150 is eliminated. Occurs. In this case, according to the image timing chart as shown in FIG.
It may be configured to scan and light in three cycles. Further, in the case of simultaneous lighting in each horizontal scanning period T according to the image signal timing chart as shown in FIG. 5, since RGB light is emitted at the same time, simultaneous additive color mixture is obtained, and as shown in FIG. The image is displayed by projecting and scanning the laser beam LB according to such an image signal timing chart.

Since the projection display device 1 has the above configuration and operation, it has the following effects. That is,
Since an image is projected by emitting and scanning a laser beam having a power density, not only can a small apparatus be displayed on a large screen, but also a screen 5 irrespective of a transmission type or a reflection type.
Reference numerals 0 and 150 indicate that the image formed by the laser beam projected on the screen is displayed without attenuated brightness because light having the same wavelength as the laser beam LB is transmitted almost completely, and light of other wavelengths is not displayed. Since the image is not transmitted, the background of the image does not become bright, and a vivid image can be displayed with high contrast on a background with high black density.

Although the present invention has been described based on the first 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.

FIG. 8 shows the screens 50 and 150 in which the filters 52 are arranged in the form of stripes as described above. It is a figure showing the structure which provided.
By arranging the light absorber 56 in the gap between the filters 52 as described above, the black density of the screens 50 and 150 may be increased, and the contrast of the screen may be further increased.

The screen has been described as the screens 50 and 150 in which the above-mentioned three types of transmitted light filters 52 having different wavelengths are arranged in a stripe shape. This filter 52 is made of a dielectric multilayer film (not shown). 450 nm, 520 nm, 650
The three-wavelength transmission filter 55 that transmits all light having wavelengths near three wavelengths of nm may be configured to cover the entire screen. In this case, the selectivity of the wavelength to be transmitted is slightly reduced. However, as shown in FIG. 11, a graph FB (B), which indicates the amount of transmitted light, from the range surrounded by the graph GSB of the spectral distribution of the sunlight SB. FB (G), F
Since the amount of light in the background is reduced only in the portion excluding the range of B (R), the amount of light in the background screen is reduced as compared with the case where the three-wavelength transmission filter 55 is not used, and the laser beam L
B can increase the contrast of the image.

Further, the transmission type screen 50 entirely covered with the three-wavelength transmission filter 55 is the reflection type screen 1 similarly covered with the three-wavelength transmission filter 55.
It is also possible to set it to 50.

In any case, although the wavelength selectivity is inferior to the screens 50 and 150 covered with the filter 52 separated into R, G and B, the positions of the screens 50 and 150 and the laser beam LB It is not necessary to adjust the scanning position, and the screens 50 and 150 can be easily installed. In a type in which the main body 2 and the screens 50 and 150 can be separated and moved, installation after the movement is extremely easy.

When a spectacle type filter 55 having a three-wavelength transmission filter 55 for selectively transmitting only the laser beam LB in the lens is used, the background light is used in the same manner as the above-described screens 50 and 150 without using a dedicated screen. The screen can use a normal white or metallic glossy reflection scattering plate,
An image with high contrast can be displayed to the user even in a bright state.

[0060]

As is apparent from the above description, claim 1
According to the projection display device of the present invention, a laser oscillator that oscillates laser light of three predetermined wavelengths used as three primary colors of additive color mixture, and corresponds to each of the three wavelengths of the image signal. A laser modulation circuit for modulating the output of the laser oscillator, and a laser modulation circuit for irradiating laser light of each wavelength whose output has been modulated by the laser modulation circuit.
A laser scanner that scans the screen two-dimensionally, and a projection surface on which the laser light is projected, and a filter that selectively transmits the three wavelengths of laser light, respectively, are provided in a parallel band shape corresponding to the main scanning line. Screens arranged side by side in an area, wherein the laser scanner is configured to project and scan the three wavelengths of laser light onto filters corresponding to the respective wavelengths. ,
There is an effect that the screen can selectively reflect only the wavelength of the laser light to be projected. Therefore,
Due to the reflection and transmission of light having a wavelength unrelated to image formation, the background screen is not brightened and the contrast of the image is not degraded. It has the effect of being able to do it.

According to a second aspect of the present invention, in addition to the effects of the first aspect of the present invention, a light absorber for absorbing light is provided between the filters. By providing the screen with the light absorber, there is an effect that the black density of the screen can be further increased. Therefore, there is an effect that the contrast of the image can be enhanced and the visibility can be further enhanced.

In the projection display device according to the third aspect of the present invention,
In addition to the effects of the projection display device according to claim 1 or 2, the laser modulation circuit modulates the laser oscillators of the three wavelengths so that the laser oscillators scan in a time corresponding to a main scanning cycle of an image signal. In the screen, the filters corresponding to the three wavelengths are 、 of the arrangement pitch of the main scanning lines.
And the laser scanner is configured to simultaneously scan laser beams of three wavelengths modulated by the laser modulation circuit for a time corresponding to a main scanning cycle of an image signal. Therefore, there is an effect that the filters corresponding to the three wavelengths of light are arranged side by side in the width of one main scan, and the laser light corresponding to the transmitted wavelength is emitted. Therefore, there is an effect that the contrast can be increased without transmitting unnecessary light and a high-resolution image can be displayed.

In the projection display device according to the fourth aspect of the present invention,
A laser oscillator that oscillates laser light of three predetermined wavelengths used as three primary colors of additive color mixing; and a laser modulation that modulates the output of the laser oscillator corresponding to each wavelength in response to each of the three wavelength image signals. A laser scanner for combining a light path of laser light of each wavelength, the output of which is modulated by the laser modulation circuit, and two-dimensionally scanning a screen while irradiating the laser light on the same light path; and projecting the laser light. A screen provided with a filter for selectively transmitting any one of the three wavelengths of laser light, thereby forming an image with the filter provided on the screen. For this reason, light other than the irradiated laser light is not transmitted, so that an image having a high contrast can be obtained. In addition, since the filter transmits laser light of any wavelength, there is an effect that it is not necessary to adjust the positions of the screen and the laser scanner.

According to a fifth aspect of the present invention, in addition to the effects of the projection display device according to any one of the first, second, and fourth aspects, the laser modulation circuit further comprises:
A laser oscillator having a wavelength is modulated so as to sequentially scan at a time of 1/3 of a time corresponding to a main scanning cycle of an image signal, and the laser scanner is driven by the laser modulation circuit.
Since the laser beam of the wavelength is sequentially scanned in a time of 1/3 of the time corresponding to the main scanning period of the image signal, the laser oscillators of the three wavelengths are not driven at the same time. There is an effect that it is not necessary to drive the laser oscillator at once with a large current.

According to a sixth aspect of the present invention, there is provided a projection display apparatus, comprising: a laser oscillator for oscillating laser beams of three wavelengths used as three additive primary colors; and a three-wavelength laser beam corresponding to each of the three wavelength image signals. A laser modulation circuit for modulating the output of a laser oscillator, a laser scanner for two-dimensionally scanning a screen while irradiating a laser light of three wavelengths whose output has been modulated by the laser modulation circuit, For observation glasses equipped with a filter that selectively transmits only light in the vicinity of the wavelength, and the observation glasses with a filter that transmits only a predetermined wavelength,
Since the image is observed, there is an effect that an image displayed on a normal screen can be viewed with high contrast even in a bright environment without using a special screen. Further, there is an effect that it is not necessary to adjust the positional relationship between the screen and the scanner.

[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. 2A is a diagram schematically showing a part of the structure of a screen 50 in the projection display device 1. FIG. FIG. 9B is a diagram illustrating a first modified example including a screen 150 using the reflection type diffusion plate 54.

FIG. 3 is a schematic diagram illustrating a laser scanner unit 10;

FIG. 4A is image data in which three input color components are combined. FIG. 5B is a diagram showing a separated signal obtained by separating R, G, and B signals from the input signal shown in FIG. FIG. 5C is a diagram showing a modulation signal for modulating the output of the laser oscillator 13 based on the separation signal shown in FIG.

FIG. 5A is image data in which three input color components are combined. FIG. 6B is a diagram showing a separated signal obtained by separating R, G, and B signals from the input signal shown in FIG. FIG. 6C is a diagram showing a modulation signal for modulating the output of the laser oscillator 13 based on the separation signal shown in FIG.

FIG. 6 is a diagram showing a position of irradiating the screen 50 with the optical paths of the laser beams LB of three colors being matched.

FIG. 7 shifts the optical path of the laser beam LB of three colors,
FIG. 4 is a diagram showing a position where light is irradiated on a screen 50.

FIG. 8 shows the screens 50 and 150 in which the filters 52 are arranged in the form of stripes as described above, and the light absorber 56 is provided between the finely divided filters of the red filter 52R, the green filter 52G and the blue filter 52B.
It is a figure showing the structure which provided.

FIG. 9A is a diagram showing an oscillation spectrum of a red laser oscillator 13R and a spectral characteristic of light transmitted through a red filter 52R. (B) is a diagram showing an oscillation spectrum of a green laser oscillator 13G and a spectral characteristic of light transmitted through a green filter 52G. (C) is a diagram showing an oscillation spectrum of a blue laser oscillator 13B and a spectral characteristic of light transmitted through a blue filter 52B.

FIG. 10 is a graph showing a spectrum of a transmission wavelength of the three-wavelength transmission filter 55.

FIG. 11 is a graph showing an outline of a spectral distribution of sunlight SB.

[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 Green laser oscillator 13B Blue laser oscillator 14A First laser beam synthesizer 14B Second laser beam synthesizer 15 Laser oscillator control unit 16 Polygon mirror control unit 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 52 Filter 52R Red filter 52G Green filter 52B Blue Filter 53 Transmission diffusion plate 54 Reflection diffusion plate 56 Light absorber LB Laser beam LB (R) Red laser beam LB (G) Green laser beam LB (B) Blue laser beam Home

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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 displays an image on a screen by projecting a laser beam and scanning the same. It relates to an enhanced projection display device.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed for displaying a color image, and a laser display is one of them. For example, Japanese Patent Application Laid-Open No. 1-245780
JP, JP-A-3-65816, JP-A-4-18
The laser beams of red (red (hereinafter, R)), green (green (hereinafter, G)), and blue (blue (hereinafter, B)), which are three primary colors of additive color mixture as described in Japanese Patent No. 1289, are respectively used as laser oscillators. Oscillate, and combine the optical paths of these outputted laser beams into one, and combine the combined laser beams onto the same point on a screen made of a scattering plate such as white to perform simultaneous additive color mixing. ,
A projection display device that displays a color image or the like on a screen by two-dimensionally scanning this at high speed has been proposed. In such a projection display device, even a small device can display a color image on a large screen by using a laser beam having a large power density.

[0003]

However, in a situation where the surroundings are bright and external light is incident on the screen, even if the laser light has a large power density, the reflected laser light has a high reflectivity because it is reflected. It is necessary to use a screen, and the screen cannot be blackened.
The background screen is brightened by the rays from the surroundings,
In some cases, black portions of the screen could not be displayed as black. In particular, in a screen using an open-type reflection / scattering plate or the like, external light was easily reflected and a high contrast could not be obtained. Therefore, when an image is projected in a bright place, there is a problem that only a low-contrast, low-visibility image that is not blackened can be displayed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and provides a projection display device capable of displaying a color image with high contrast and high visibility by lowering the black level of a background screen even in a bright surrounding. With the goal.

[0005]

To achieve this object, a projection display apparatus according to the first aspect of the present invention comprises: A laser modulation circuit for modulating the output of the laser oscillator corresponding to each of the three wavelengths of image signals, and irradiating a laser beam of each wavelength whose output has been modulated by the laser modulation circuit. A laser scanner that scans the screen two-dimensionally, and a projection surface on which the laser light is projected, and a filter that selectively transmits the three wavelengths of laser light, respectively, are provided in parallel with each other corresponding to the main scanning line. A screen arranged side by side in a band-shaped area, wherein the laser scanner projects and scans the three wavelength laser beams onto filters corresponding to the respective wavelengths. Characterized in that it is configured.

[0006] In the projection display device according to this configuration, the screen can selectively reflect only the wavelength of the laser light to be projected. Therefore, the background screen is not brightened by the reflection or transmission of light having a wavelength unrelated to image formation, so that the contrast of the image does not decrease. be able to.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, a light absorber for absorbing light is provided between the filters. It is characterized by having.

[0008] In the projection display device according to this configuration, the black density of the screen can be further increased by providing the screen with the light absorber. Therefore, the contrast of the image can be increased, and the visibility can be further improved.

[0009] 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 laser modulation circuit modulates the three wavelength lasers in synchronization with each other so as to scan at a time corresponding to a main scanning period of an image signal. In the screen, the filters corresponding to the three wavelengths are 、 of the arrangement pitch of the main scanning lines.
And the laser scanner is configured to simultaneously scan laser beams of three wavelengths modulated by the laser modulation circuit at a time corresponding to a main scanning cycle of an image signal. It is characterized by.

[0010] In the projection display apparatus according to this configuration, the filters corresponding to the light of three wavelengths are arranged side by side in the width of one main scan, and the laser light corresponding to the transmitted wavelength is irradiated. Therefore, the contrast can be increased without transmitting light of an unnecessary wavelength, and an image with high resolution can be displayed.

[0011] In the projection display device according to the fourth aspect of the invention,
A laser oscillator that oscillates laser light of three predetermined wavelengths used as three primary colors of additive color mixing; and a laser modulation that modulates the output of the laser oscillator corresponding to each wavelength in response to each of the three wavelength image signals. A laser scanner for combining a light path of laser light of each wavelength, the output of which is modulated by the laser modulation circuit, and two-dimensionally scanning a screen while irradiating the laser light on the same light path; and projecting the laser light. A screen provided with a filter for selectively transmitting any of the three wavelengths of laser light.

In the projection display device according to this configuration, since a filter provided on the screen does not transmit light other than the laser light irradiated for image formation, an image with high contrast can be obtained. Further, since the filter transmits laser light of any wavelength, it is not necessary to adjust the positions of the screen and the laser scanner.

According to a fifth aspect of the present invention, in addition to the configuration of the projection display device according to any one of the first, second and fourth aspects, the laser modulation circuit comprises
A laser oscillator having a wavelength is modulated so as to sequentially scan at a time of 1/3 of a time corresponding to a main scanning cycle of an image signal, and the laser scanner is driven by the laser modulation circuit.
The laser beam of the wavelength is sequentially scanned in a time of 1/3 of a time corresponding to the main scanning cycle of the image signal.

In the projection display apparatus according to this configuration, since the laser oscillators of three wavelengths are not driven at the same time, it is not necessary to drive the laser oscillators at once with a large current.

According to a sixth aspect of the present invention, there is provided a projection display apparatus comprising: a laser oscillator for oscillating laser light of three wavelengths used as three primary colors of additive color mixing; A laser modulation circuit for modulating the output of a laser oscillator, a laser scanner for two-dimensionally scanning a screen while irradiating three wavelength laser light whose output has been modulated by the laser modulation circuit, Observation glasses provided with a filter that selectively transmits only light near the wavelength.

In the projection display apparatus according to this configuration, the filter that transmits only a predetermined wavelength is used as observation glasses.
Since an image is observed, an image displayed on a normal screen can be viewed with high contrast even in a bright environment without using a special screen. Also, there is no need to adjust the positional relationship between the screen and the scanner.

[0017]

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, an outline of the configuration of the projection display device 1 is shown in FIG.
This will be described with reference to FIG.

As shown in FIG. 1, a 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.

[0019]
The projection display device 1 is configured to perform image processing based on image data input to the image input unit 47 via the interface 48.
A signal is sent from the control unit 40 to the scanner control unit 12, and a driving signal is generated by the laser oscillator control unit 15 of the scanner control unit 12, and the red laser oscillator 13R, the green laser oscillator 13G, and the blue laser oscillator 13G provided in the laser scanner unit 10 are provided. A laser oscillator 13B (see FIG. 3; hereinafter, these are collectively referred to as a laser oscillator 13) is oscillated to generate a red laser beam L.
B (R), green laser beam LB (G), and blue laser beam LB (B) emit light.
The laser beam LB is projected onto the screen 50 while being two-dimensionally scanned by the main scanning polygon mirror (rotating polygon mirror) 17 and the sub-scanning polygon mirror 18 (hereinafter collectively referred to as polygon mirrors 17 and 18). An image is formed.

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.

FIG. 2A is a view showing a state in the projection display device 1.
FIG. 3 is a diagram schematically illustrating a part of the structure of a screen 50.
According to FIG. 2A, the screen 5 of the present embodiment
0 will be explained. First, the projection display device 1 of the present embodiment
Screen 50 in is a transmissive screen, the main body 2 is arranged not shown Oite upper right in FIG. 2 (A) (see FIG. 1). Here, for convenience of explanation,
LB (R), L instead of light with complex spectrum
It is assumed that a laser beam LB composed of B (G) and LB (B) is emitted from the upper right to the lower left. Then, a viewer of the image (hereinafter, referred to as a user U) views the image drawn by the laser beam LB from the transmission type diffusion plate 53 through the filter 52 from the lower left in the figure. Transmission diffusion plate 53
The body 2 has a red filter 52 that is finely divided.
A large number of R, green filters 52G, and blue filters 52B (hereinafter, referred to as filters 52) are arranged in stripes. As the filter 52, a primary color dye filter is used. The dye filter can be manufactured in a printing process, can be easily realized by printing in a stripe shape on the screen 50, and is more cost-effective than the interference filter. Although the figure is deformed and drawn thicker for the sake of explanation, the actual filter 52 is an extremely thin film printed on the transmission type diffusion plate 53 as described above. Has a negligible thickness.

FIG. 9 is a graph showing the oscillation spectrum of the laser oscillator 13 and the spectral characteristics of the transmitted light FB of the filter 52. The vertical axis indicates the light intensity at that wavelength in the case of the laser oscillator 13 and the transmittance at that wavelength in the case of the filter 52. The horizontal axis represents the wavelength λ to be emitted or transmitted, and the unit is nm (nanometer).

First, FIG. 9A shows a red laser oscillator 1.
3 shows an oscillation spectrum of 3R and a spectral characteristic of light transmitted through the red filter 52R. As shown in FIG. 9A, the oscillation spectrum of the red laser oscillator 13R is approximately 650 n
substantially in the vicinity of m showing the spectrum of a very narrow range of unimodal. With respect to the oscillation spectrum of the red laser oscillator 13R, the transmitted light of the red filter 52R transmits light of a long wavelength including the oscillation spectrum of the red laser oscillator 13R, and absorbs light of wavelengths of other colors. Resulting in. The wavelength exceeding 780 nm is not visible light,
Further, since a wavelength of about 730 nm or more can be sensuously ignored, it has the same effect as not transmitting the light to the user, and does not make the screen 50 feel bright. On the other hand, from the red laser oscillator 13R to the red filter 52R
The laser beam LB emitted in the above is transmitted efficiently without substantially attenuating the light amount. That is, it can be seen that light of a visible wavelength other than the red laser beam LB (R) is not transmitted.

However, in the case of the laser beam LB having an extremely narrow spectrum width, the amount of light is extremely small as compared with sunlight SB or the like. However, when compared in a specific range of wavelengths, the laser beam LB has an extremely narrow spectrum range. Since the power is concentrated on an extremely small area on the screen 50, the amount of light per unit is sufficiently large as compared with sunlight SB or the like, and the light becomes sufficiently strong to display an image. Therefore, the user can see the vivid red pure color of the red laser beam LB (R) in a tight background with a high black level.

Next, FIG. 9B shows the green laser oscillator 13.
9 shows an oscillation spectrum of G and a spectral characteristic of light transmitted through the green filter 52G. Also in this case, similarly to the case of the above-described red laser oscillator 13R and red filter 52R, the green filter 52G transmits only light having a wavelength near 520 nm which is the oscillation wavelength of the green laser oscillator 13G. Therefore, unlike the red filter 52R, not only light having a shorter wavelength but also light having a longer wavelength is cut off. Also in this case, since the light other than the green light is absorbed and not transmitted, the total amount of transmitted light is reduced, and the amount of light is reduced, resulting in a sensually blackish color tone and a tight background. The green laser beam LB (G) of the green laser is
Since the light is transmitted without being attenuated, a bright green image is drawn on the transmission diffusion plate 53.

FIG. 9C shows a blue laser oscillator 13B.
And the spectral characteristics of light transmitted through the blue filter 52B. As shown in FIG. 9C, the blue laser oscillator 13B oscillates a blue laser beam LB (B) having a narrow band wavelength centered on 450 nm, and the blue filter 52B has a narrow range of wavelengths corresponding to this wavelength. This is a configuration in which only light is transmitted, and similarly to filters of other colors, since transmitted light is usually small, it is sensuously observed as dark.

FIG. 11 is a graph schematically showing the spectral distribution of sunlight SB. The graph shown by the solid line is a graph showing the spectrum of sunlight SB, and the graph G52B, G52G, G52R shown by the chain line is a graph showing the transmittance of each filter 52. Further, graphs FB (B), FB (G), F
B (R) indicates the light intensity of the transmitted light of the sunlight SB transmitted through the filters G52B, G52G, and G52R, respectively.
It can be seen from the graph of FIG. 11 that even if an extremely large amount of light including light beams of various spectra such as sunlight SB hits the main body 2 side of the red filter 52R, for example, it can be understood from the graph. The sunlight S
Most of the light amount of B is absorbed, and only a small amount of transmitted light FB (R) is transmitted therethrough. Further, the wavelength to be transmitted is only the wavelength of the red light, but similarly, the transmitted light FB of the green and blue filters 52G and 52B transmitted therethrough.
Is mixed with white light, but the total amount of transmitted light FB (R) is smaller than that of sunlight SB. Therefore, a user who is functionally located on the opposite side of the screen has a dark background. Is maintained. That is, it looks dark.

Returning to FIG. 2A again, as shown here, the red, green, and blue laser beams LB (R), LB hitting the red filter 52R.
(G) and LB (B) indicate that the red filter 52R is 650.
Since only light having a wavelength near nm is transmitted, light having a wavelength other than red is absorbed, and as a result,
Only the red laser beam LB (R) reaches. Further, in the portion of the other red filter 52R where the red laser beam LB (R) of the red laser oscillator 13R is not irradiated, the amount of red light passing therethrough is small and looks blackish in appearance. Similarly, for the other green and blue colors, only the green laser beam LB (G) and the blue laser beam LB (B) are transmitted, and the other light beams are hardly transmitted. Is translucent,
Because the filter 52 looks dark, the user U visually forms a dark background, and the user U can see an image by the bright laser beam LB while the black level is low (dark).

In the present embodiment, the projection display apparatus 1 uses the transmission screen 50, but this screen may be a reflection screen. Here, FIG. 2B is a diagram illustrating a first modified example including a screen 150 using the reflection type diffusion plate 54. As shown in FIG. 2B, light R, G, and B traveling toward the screen 150 are:
When the light strikes the red filter 152R, G and B are absorbed and attenuated. On the other hand, the red laser beam LB (R) composed of a red light beam enters the red filter 152R, strikes the reflection type diffusion plate 154 and is reflected. In FIG. 2B, the filter 152 is drawn thick for the sake of explanation. However, in actuality, as described above, the filter 152 is extremely thin and can be manufactured only by printing, and refraction is almost negligible. Therefore, the transmission type screen 50 is different from the transmission type screen 50 in that the light passes back and forth through the filter 152 before and after the reflection, but the basic configuration is the same as that of the structure for transmitting only light of a specific narrow band wavelength. Even if the surroundings are bright, most of the light that hits the screen 150 is absorbed, so that the screen becomes a background with a low black level, and the filter 15
The image formed by only the laser beam LB of the specific wavelength transmitted through 2 is visually perceived by the user U, and the user U can see the image drawn by the vivid laser beam LB on a black background screen even in a bright surrounding. it can.

FIG. 3 is a schematic diagram for explaining the laser scanner section 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 three-wavelength laser oscillator. An He-Ne laser is applied to the red laser oscillator 13R that emits red light, and an H-Ne laser is applied to the blue laser oscillator 13B that emits blue light.
An Ar laser is suitably used for the green laser oscillator 13G in which the e-Cd laser emits green light.

The laser beams LB (R), LB (G), L
B (B) is combined into a laser beam LB having one optical axis by a first laser beam combiner 14A and a second laser beam combiner 14B (hereinafter referred to as laser beam combiner 14). First, the red laser oscillator 13R and the green laser oscillator 13G are combined by the first laser beam combiner 14A. The first laser beam combiner 14A is composed of a dichroic mirror (wavelength selective reflector), and emits a red laser beam L emitted from a red laser oscillator 13R.
B (R) is transmitted, but the green laser beam LB (G) emitted from the green laser oscillator 13G is made of a material that reflects the light depending on the wavelength of the output light. Therefore, the red laser beam LB (R) and the green laser beam LB (G) respectively emitted from the red laser oscillator 13R and the green laser oscillator 13G disposed orthogonally to the first laser beam combiner 14A are converted into a red laser beam. Beam LB
(R) passes through the dichroic mirror and travels straight, and the green laser beam LB (G) is reflected by the dichroic mirror and its optical axis is deflected at a right angle. Is adjusted to have an optical axis of

Similarly, the second laser beam combiner 14B combines the red laser beam LB (R) and the green laser beam LB (G) with the blue laser beam LB (LB) emitted by the blue laser oscillator 13B. B) is synthesized, and the original input color can be reproduced. In addition, the composition of these three color laser beams LB may be a dichroic prism or a configuration in which light beams are combined by a prism using a difference in refractive index depending on the wavelength. May be combined into one optical path.

FIG. 6 shows a three-color laser beam LB.
FIG. 6 is a diagram showing a position where the light path is irradiated onto the screen 50 by matching the optical paths of FIG. As shown in FIG. 6, the screen 50 of the projection display device 1 has three filters 52 of red, green,
The stripes are arranged alternately in the order of blue. These red, green and blue filters 52R, 52G, 52B
Are arranged in a width d in which the main scanning is performed once in three rows.
In other words, the width of each filter 52 indicates a width that is １ ／ of the width d that is main-scanned at one time.

Laser beam L combined into one optical path
B is irradiated and scanned with a width corresponding to the width d of this one main scan. When the screen 50 is irradiated in one optical path by mixing the three color components as described above, the red, green, and blue filters 52R, 52G, and 52B are simultaneously irradiated as described in the description of the screen 50 described above. Even in this case, for example, since the component of the red laser beam LB (R) passes through only the red filter 52R, even if the component of the red laser beam LB (R) hits another color filter, the user U can convert the image of the red laser beam LB (R) to another color. There is no observation through the filter. Similarly, the green laser beam LB
(G), since the blue laser beam LB (B) transmits only the light that has hit the green filter 52 (G) and the blue filter 52 (B), the light of each color passes through the filter 52 of each color. As a result, it becomes light for forming an image. In this case, the filters 52 of three colors of red, green and blue are formed in the width d of one main scan and are very close to each other. Then, the light of the blue component is again subjected to side-by-side additive color mixing, and an image reproduced in the original color tone of the image information can be observed.

In the projection display apparatus 1 according to the present embodiment, the laser beams LB of three colors are combined into one optical path. Laser beam LB (R), L
The optical paths of B (G) and LB (B) can be adjusted.
Hereinafter, the three color laser beams LB (R) and LB
A second modification example in which scanning is performed with the optical paths of (G) and LB (B) separated will be described.

FIG. 7 shows a laser beam LB of three colors.
FIG. 5 is a diagram showing a position where the optical path is shifted to irradiate the screen 50. As shown in FIG.
This is the same as that shown in FIG. 6 in which the color filters 52 are alternately arranged in stripes in the order of red, green, and blue. Accordingly, the red, green, and blue filters 52R, 52G, and 52B are arranged in three rows with a width d that is main-scanned at one time. The scanner 11 applies laser beams LB (R), LB (G), and LB traveling on the optical paths separated into three colors to the three-color filters 52R, 52G, and 52B.
(B) is configured to be irradiated and scanned. In this case, the light flux of each laser beam LB is 1
It is 1/3 of the width d of the main scanning. In this case, for example, the red laser beam LB (R) in FIG. 7 is irradiated only to the red filter 52R. The efficiency of the light to be formed is high.

Next, the laser beam LB of the projection display device 1
Will be described with reference to FIGS. 1 and 3. 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 is a regular hexagonal prism having a height lower than the bottom surface as shown in FIG. 3, and is disposed at a position where a line whose rotation axis is horizontal and which is 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 oscillator LB provided in the scanner controller 12 and the polygon mirror controller are provided so that the laser beam LB reflected by the main scanning polygon mirror 17 is not projected out of a predetermined angle range. 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).
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 transmitted 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. 3 on the screen 50, and one line of images 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 below it 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 the 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 one-sided mirror). However, it is preferable to use a polygon mirror using a polygon mirror since there is no change in the angular velocity than using a galvanometer.

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

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) in one screen is reduced to 1/3.
The sub-scanning (vertical scanning) of 0 seconds is performed, and a smooth screen with little flicker can be projected.

Returning to FIG. 1, to continue the description, as described above, the scanner control unit 12 includes the laser oscillator control unit 15
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. 3).
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 has a storage means which is also a developing place for developing the image data.
As input data, a general RGB video signal is input via the interface 48. The input signal is not limited to this, and a signal of various types may be input.

Next, FIGS. 4A to 4C show the projection display device 1 in the case of irradiating the laser beams LB of three colors to the same position on the screens 50 and 150 in the same optical path as shown in FIG. 5 shows an image signal timing chart of FIG. The vertical axis represents the intensity V of the input signal and the intensity VR, VG of the separated signal of each color.
VB is schematically shown, the horizontal axis represents the passage of time, T represents the time of the horizontal scanning cycle of the input signal, and Δt
Indicates the time of the horizontal scanning period actually scanned by the projection display device 1. As shown in FIG. 4, when irradiating the same position, the red laser oscillator 13R, the green laser oscillator 13G, and the blue laser oscillator 13B are sequentially switched to be sequentially turned on at every Δt of 時間 of the time of each horizontal scanning cycle T. Let it.

FIG. 4A shows image data in which the input three color components are combined. This image data is input to the image input unit 47 once. FIG. 4B is a diagram illustrating a separated signal obtained by separating the R, G, and B signals from the input signal illustrated in FIG. As shown in FIG. 4B, the signals are separated into three color separation signals. Next, FIG. 4C is a diagram showing a modulation signal for modulating the output of the laser oscillator 13 based on the separation signal shown in FIG. 4B. Then, the separation signal of the horizontal scanning period T is converted into a laser modulation signal. At this time, the length of the modulation signal which is a drive signal of the laser oscillator 13 is changed to an image signal as shown in FIG. R
It is assumed that the GB separation signal is a signal whose time is reduced to 1/3. Therefore, the laser emission time by each laser oscillator 13 is emitted and scanned by a length of 1/3 of the horizontal scanning period T of the original image signal. Then, scanning is performed so as to have an image length T by scanning of three colors of RGB. As a result, the color image data of the image data is reproduced on the screens 50 and 150 by successive additive color mixing. As described above, since the laser oscillator 13 is not simultaneously turned on by sequentially scanning, it is possible to reduce the power without outputting a large output at a time.

On the other hand, FIGS. 5A and 5B show three color laser beams LB as shown in FIG.
In the case where the scanning is set so that the optical path is shifted by 1/3 of the width d of one main scanning on the zero, the scanning is performed.
5 shows an image signal timing chart in the case of lighting simultaneously in each horizontal scanning cycle T.

FIG. 5A shows image data in which the input three color components are combined. This image data is input to the image input unit 47 once. FIG. 5B is a diagram showing a separated signal obtained by separating the R, G, and B signals from the input signal shown in FIG. 5A. As shown in FIG. 5B, the signals are separated into three color separation signals. FIG. 5C is a diagram illustrating a modulation signal that modulates the output of the laser oscillator 13 based on the separation signal illustrated in FIG. Then, the separation signal of the horizontal scanning period T is converted into a laser modulation signal. At this time, the horizontal scanning period T of the modulation signal which is the drive signal of the laser oscillator 13 is changed as shown in FIG. The image signal R
The GB separation signal is used as a modulation signal in the horizontal scanning period T as it is. Then, R synchronized from the laser oscillator controller 15
The GB modulated signal is sent to each laser oscillator 13 at the same time, and is emitted and scanned at the same time. Then, scanning is performed so that the image length becomes T by simultaneous scanning of three colors of RGB. As a result, the color image data of the image data is reproduced on the screens 50 and 150 by the juxtaposed additive color mixture.

As shown in FIG. 6, laser beams LB of three colors are used.
May be simultaneously illuminated in the horizontal scanning period T according to the image signal timing chart as shown in FIG. Conversely, as shown in FIG. 7, the screen 50, the screen 50,
Even in the case of irradiating a different position on 150, it may be configured to turn on the light sequentially for one-third of the horizontal scanning period T according to an image timing chart as shown in FIG.

Further, the configuration is the same as that of the projection display apparatus 1 of the present embodiment, except that the entire screen is covered by a three-wavelength transmission filter 55 (not shown) instead of having the three-color filter 52. You can also. In such a case, an image can be displayed by projecting and scanning the laser beam LB according to an image signal timing chart as shown in FIG. 4 or FIG. Here, FIG.
0 shows the spectrum of the transmission wavelength of the three-wavelength transmission filter 55. By using such a filter, the selectivity of the wavelength is reduced, which is slightly disadvantageous in that the contrast of the image is increased. However, the effect of eliminating the need to align the positions of the laser beam LB and the screens 50 and 150 is eliminated. Occurs. In this case, according to the image timing chart as shown in FIG.
It may be configured to scan and light in three cycles. Further, in the case of simultaneous lighting in each horizontal scanning period T according to the image signal timing chart as shown in FIG. 5, since RGB light is emitted at the same time, simultaneous additive color mixture is obtained, and as shown in FIG. The image is displayed by projecting and scanning the laser beam LB according to such an image signal timing chart.

Since the projection display device 1 has the above configuration and operation, it has the following effects. That is,
Since an image is projected by emitting and scanning a laser beam having a power density, not only can a small apparatus be displayed on a large screen, but also a screen 5 irrespective of a transmission type or a reflection type.
Reference numerals 0 and 150 indicate that the image formed by the laser beam projected on the screen is displayed without attenuated brightness because light having the same wavelength as the laser beam LB is transmitted almost completely, and light of other wavelengths is not displayed. Since the image is not transmitted, the background of the image does not become bright, and a vivid image can be displayed with high contrast on a background with high black density.

Although the present invention has been described based on the first 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.

FIG. 8 shows the screens 50 and 150 in which the filters 52 are arranged in the form of stripes as described above. It is a figure showing the structure which provided.
By arranging the light absorber 56 in the gap between the filters 52 as described above, the black density of the screens 50 and 150 may be increased, and the contrast of the screen may be further increased.

The screen has been described as the screens 50 and 150 in which the above-mentioned three types of transmitted light filters 52 having different wavelengths are arranged in a stripe shape. This filter 52 is made of a dielectric multilayer film (not shown). 450 nm, 520 nm, 650
The three-wavelength transmission filter 55 that transmits all light having wavelengths near three wavelengths of nm may be configured to cover the entire screen. In this case, the selectivity of the wavelength to be transmitted is slightly reduced. However, as shown in FIG. 11, a graph FB (B), which indicates the amount of transmitted light, from the range surrounded by the graph GSB of the spectral distribution of the sunlight SB. FB (G), F
Since the amount of light in the background is reduced only in the portion excluding the range of B (R), the amount of light in the background screen is reduced as compared with the case where the three-wavelength transmission filter 55 is not used, and the laser beam L
B can increase the contrast of the image.

Further, the transmission type screen 50 entirely covered with the three-wavelength transmission filter 55 is the reflection type screen 1 similarly covered with the three-wavelength transmission filter 55.
It is also possible to set it to 50.

In any case, although the wavelength selectivity is inferior to the screens 50 and 150 covered with the filter 52 separated into R, G and B, the positions of the screens 50 and 150 and the laser beam LB It is not necessary to adjust the scanning position, and the screens 50 and 150 can be easily installed. In a type in which the main body 2 and the screens 50 and 150 can be separated and moved, installation after the movement is extremely easy.

When a spectacle type filter 55 having a three-wavelength transmission filter 55 for selectively transmitting only the laser beam LB in the lens is used, the background light is used in the same manner as the above-described screens 50 and 150 without using a dedicated screen. The screen can use a normal white or metallic glossy reflection scattering plate,
An image with high contrast can be displayed to the user even in a bright state.

[0060]

As is apparent from the above description, claim 1
According to the projection display device of the present invention, a laser oscillator that oscillates laser light of three predetermined wavelengths used as three primary colors of additive color mixture, and corresponds to each of the three wavelengths of the image signal. A laser modulation circuit for modulating the output of the laser oscillator, and a laser modulation circuit for irradiating laser light of each wavelength whose output has been modulated by the laser modulation circuit.
A laser scanner that scans the screen two-dimensionally, and a projection surface on which the laser light is projected, and a filter that selectively transmits the three wavelengths of laser light, respectively, are provided in a parallel band shape corresponding to the main scanning line. Screens arranged side by side in an area, wherein the laser scanner is configured to project and scan the three wavelengths of laser light onto filters corresponding to the respective wavelengths. ,
There is an effect that the screen can selectively reflect only the wavelength of the laser light to be projected. Therefore,
Due to the reflection and transmission of light having a wavelength unrelated to image formation, the background screen is not brightened and the contrast of the image is not degraded. It has the effect of being able to do it.

According to a second aspect of the present invention, in addition to the effects of the first aspect of the present invention, a light absorber for absorbing light is provided between the filters. By providing the screen with the light absorber, there is an effect that the black density of the screen can be further increased. Therefore, there is an effect that the contrast of the image can be enhanced and the visibility can be further enhanced.

In the projection display device according to the third aspect of the present invention,
In addition to the effects of the projection display device according to claim 1 or 2, the laser modulation circuit modulates the laser oscillators of the three wavelengths so that the laser oscillators scan in a time corresponding to a main scanning cycle of an image signal. In the screen, the filters corresponding to the three wavelengths are 、 of the arrangement pitch of the main scanning lines.
And the laser scanner is configured to simultaneously scan laser beams of three wavelengths modulated by the laser modulation circuit for a time corresponding to a main scanning cycle of an image signal. Therefore, there is an effect that the filters corresponding to the three wavelengths of light are arranged side by side in the width of one main scan, and the laser light corresponding to the transmitted wavelength is emitted. Therefore, there is an effect that the contrast can be increased without transmitting unnecessary light and a high-resolution image can be displayed.

In the projection display device according to the fourth aspect of the present invention,
A laser oscillator that oscillates laser light of three predetermined wavelengths used as three primary colors of additive color mixing; and a laser modulation that modulates the output of the laser oscillator corresponding to each wavelength in response to each of the three wavelength image signals. A laser scanner for combining a light path of laser light of each wavelength, the output of which is modulated by the laser modulation circuit, and two-dimensionally scanning a screen while irradiating the laser light on the same light path; and projecting the laser light. A screen provided with a filter for selectively transmitting any one of the three wavelengths of laser light, thereby forming an image with the filter provided on the screen. For this reason, light other than the irradiated laser light is not transmitted, so that an image having a high contrast can be obtained. In addition, since the filter transmits laser light of any wavelength, there is an effect that it is not necessary to adjust the positions of the screen and the laser scanner.

According to a fifth aspect of the present invention, in addition to the effects of the projection display device according to any one of the first, second, and fourth aspects, the laser modulation circuit further comprises:
A laser oscillator having a wavelength is modulated so as to sequentially scan at a time of 1/3 of a time corresponding to a main scanning cycle of an image signal, and the laser scanner is driven by the laser modulation circuit.
Since the laser beam of the wavelength is sequentially scanned in a time of 1/3 of the time corresponding to the main scanning period of the image signal, the laser oscillators of the three wavelengths are not driven at the same time. There is an effect that it is not necessary to drive the laser oscillator at once with a large current.

According to a sixth aspect of the present invention, there is provided a projection display apparatus, comprising: a laser oscillator for oscillating laser beams of three wavelengths used as three additive primary colors; and a three-wavelength laser beam corresponding to each of the three wavelength image signals. A laser modulation circuit for modulating the output of a laser oscillator, a laser scanner for two-dimensionally scanning a screen while irradiating a laser light of three wavelengths whose output has been modulated by the laser modulation circuit, For observation glasses equipped with a filter that selectively transmits only light in the vicinity of the wavelength, and the observation glasses with a filter that transmits only a predetermined wavelength,
Since the image is observed, there is an effect that an image displayed on a normal screen can be viewed with high contrast even in a bright environment without using a special screen. Further, there is an effect that it is not necessary to adjust the positional relationship between the screen and the scanner.

[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. 2A is a diagram schematically showing a part of the structure of a screen 50 in the projection display device 1. FIG. FIG. 9B is a diagram illustrating a first modified example including a screen 150 using the reflection type diffusion plate 54.

FIG. 3 is a schematic diagram illustrating a laser scanner unit 10;

FIG. 4A is image data in which three input color components are combined. FIG. 5B is a diagram showing a separated signal obtained by separating R, G, and B signals from the input signal shown in FIG. FIG. 5C is a diagram showing a modulation signal for modulating the output of the laser oscillator 13 based on the separation signal shown in FIG.

FIG. 5A is image data in which three input color components are combined. FIG. 6B is a diagram showing a separated signal obtained by separating R, G, and B signals from the input signal shown in FIG. FIG. 6C is a diagram showing a modulation signal for modulating the output of the laser oscillator 13 based on the separation signal shown in FIG.

FIG. 6: Matching the optical paths of the laser beams LB of three colors,
FIG. 4 is a diagram showing a position where light is irradiated on a screen 50.

FIG. 7 is a diagram illustrating positions where the optical paths of the laser beams LB of three colors are shifted to irradiate the screen 50;

FIG. 8 shows the screens 50 and 150 in which the filters 52 are arranged in the form of stripes as described above, and the light absorber 56 is provided between the finely divided filters of the red filter 52R, the green filter 52G and the blue filter 52B.
It is a figure showing the structure which provided.

FIG. 9A is a diagram showing an oscillation spectrum of a red laser oscillator 13R and a spectral characteristic of light transmitted through a red filter 52R. (B) is a diagram showing an oscillation spectrum of a green laser oscillator 13G and a spectral characteristic of light transmitted through a green filter 52G. (C) is a diagram showing an oscillation spectrum of a blue laser oscillator 13B and a spectral characteristic of light transmitted through a blue filter 52B.

FIG. 10 is a graph showing a spectrum of a transmission wavelength of the three-wavelength transmission filter 55.

FIG. 11 is a graph showing an outline of a spectral distribution of sunlight SB.

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 Green laser oscillator 13B Blue laser oscillator 14A First laser beam synthesizer 14B Second laser beam synthesizer Reference Signs List 15 laser oscillator control unit 16 polygon mirror control unit 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 52 filter 52R red filter 52G Green filter 52B Blue filter 53 Transmission diffusion plate 54 Reflection diffusion plate 56 Light absorber LB Laser beam LB (R) Red laser beam LB (G) Green laser beam LB (B ) Blue laser beam

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C060 EA02 GC01 HC16 HC24 JA17 JB06 5C080 AA07 AA18 BB06 CC02 CC03 DD03 DD13 DD30 EE01 EE17 EE28 FF12 GG02 JJ01 JJ02 JJ05 JJ06 5G435 AA00 AA01 AA02 DD05 DD06 DD06 DD06 FF14 GG10 GG11 GG21 GG28 GG46

Claims (6)

[Claims] A predetermined three color used as three primary colors of additive color mixture.
A laser oscillator that oscillates laser light of each wavelength; a laser modulation circuit that modulates the output of the laser oscillator corresponding to each of the three wavelengths in response to each of the three wavelength image signals; A laser scanner that scans a screen two-dimensionally while irradiating modulated laser light of each wavelength; and a projection surface on which the laser light is projected, wherein the laser light of each of the three wavelengths is selectively transmitted. A filter provided in parallel with a parallel band-shaped region corresponding to the main scanning line, wherein the laser scanner projects the three wavelengths of laser light onto the filters corresponding to the respective wavelengths. A projection display device configured to scan. 2. The projection display device according to claim 1, further comprising a light absorber that absorbs light in a gap between each of the filters. 3. The laser modulation circuit modulates the three-wavelength laser oscillator synchronously so as to scan at a time corresponding to a main scanning period of an image signal, and the screen includes a filter corresponding to the three wavelengths. Are arranged at an arrangement pitch of 1/3 of the arrangement pitch of the main scanning lines. The laser scanner emits three wavelengths of laser light
3. The projection display device according to claim 1, wherein the projection display device is configured to scan simultaneously at a time corresponding to a main scanning cycle of the image signal. 4. A predetermined three color used as three primary colors of additive color mixture
A laser oscillator that oscillates laser light of each wavelength; a laser modulation circuit that modulates the output of the laser oscillator corresponding to each of the three wavelengths in response to each of the three wavelength image signals; A laser scanner that combines the optical paths of the modulated laser lights of the respective wavelengths and scans the screen two-dimensionally while irradiating the laser light on the same optical path; and a projection surface on which the laser light is projected, wherein A screen provided with a filter for selectively transmitting any one of the laser beams having the wavelengths. 5. The laser modulation circuit modulates the three-wavelength laser oscillator so that the laser oscillator sequentially scans for one-third of a time corresponding to a main scanning period of an image signal. 3. The apparatus according to claim 1, wherein the laser light of three wavelengths modulated by the modulation circuit is sequentially scanned at a time corresponding to one third of a time corresponding to a main scanning period of the image signal. The projection display device according to claim 2. 6. A laser oscillator that oscillates laser light of three wavelengths used as three primary colors of additive color mixing, and a laser modulation circuit that modulates the output of the laser oscillator of three wavelengths in accordance with each image signal of the three wavelengths. A laser scanner that scans a screen two-dimensionally while irradiating three-wavelength laser light whose output has been modulated by the laser modulation circuit; and selectively transmits only light near the wavelength of the three-wavelength laser light. And a pair of observation glasses provided with a filter.