JP4111947B2 - Manufacturing method of laser light screen - Google Patents

Description

  The present invention relates to a screen (also referred to as a display device depending on the shape) that is irradiated with a laser beam emitted from a laser projector or the like, and more particularly to improvement of definition in the image display.

  A projector using a normal halogen lamp as a light source uses an incoherent light to obtain an image, so the light power per pixel is not so strong, and the screen is only embossed. If focus is achieved, sufficient resolution can be obtained.

  In contrast, a laser projector has a high energy density in order to obtain an image using coherent laser light, and the optical power per pixel is strong on the principle of drawing one pixel with a spot of a laser beam. In ordinary screens and walls, light blur occurs, causing a decrease in contrast and a decrease in sharpness.

  In order to colorize laser projectors, a method in which lasers of three primary colors (red, green, and blue) of light are used, and each of them is combined and irradiated on the same optical path after being modulated has already been put into practical use.

  Also, a laser projector has been proposed in which a black portion is provided by blocking laser light between pixels in order to display text and images clearly on a screen (Patent Document 1).

On the other hand, blue light-emitting diodes are commercially available, and caps covering diodes are also commercially available, which use blue light as a light source and add a material that converts blue light into red and green to produce white light. If a diode with this cap is used, white light can be produced with only one type of diode without using a diode of the three primary colors of light. Although color LED display is possible based on this principle, since red and green diodes are less expensive than blue diodes, color LED displays based on light conversion have not been put to practical use.
JP 2002-296777 A

  As described above, a laser projector has a problem that blurring of light occurs on a normal screen or a wall and the sharpness is lowered. Further, the proposal of Patent Document 1 has a problem that although the sharpness can be improved, the laser beam is mechanically turned on and off by the chopper in synchronization with the image signal, so that the control mechanism becomes complicated.

The present invention has been made under such circumstances, and it is an object of the present invention to provide a method for manufacturing a laser light screen capable of displaying a clear image without blurring with a simple configuration.

In order to solve the above problems, in the present invention, a method for manufacturing a laser beam screen is configured as described in the following (1) to ( 6 ).
(1) A method for manufacturing a laser light screen, in which a pixel portion of a plastic material including a diffusing material for diffusing light is formed in the concave portion of a black plastic plate having a plurality of concave portions.
(2) In the method for manufacturing a laser light screen according to (1),
The plastic plate is a method for manufacturing a laser beam screen which is molded by a mold.
(3) In the method for manufacturing a screen for laser light according to (1) or (2),
The pixel portion is a method for manufacturing a screen for laser light, in which a liquid plastic material is applied to the concave portion, filled, and cured.
(4) In the method for manufacturing a screen for laser light according to (1) or (2),
The said pixel part is a manufacturing method of the screen for laser beams which forms a liquid plastic material in the said recessed part by printing with a screen printing method.
(5) A method for manufacturing a screen for laser light, in which a plurality of pixel portions made of a plastic material including a diffusing material for diffusing light are formed on a black plastic plate or black plastic film by screen printing at intervals from each other. .
(6) A laser beam screen in which a plurality of pixel portions made of a plastic material including a diffusing material for diffusing light are formed on a black plated metal plate or black metal film by screen printing at intervals. Manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the screen for laser beams which can display a clear monochrome or color image without a blur with simple structure can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  FIG. 1 is an enlarged view of a portion of a “laser beam screen” according to a first embodiment, where (a) is a plan view thereof and (b) is a cross-sectional view taken along line AA. . In FIG. 1, reference numeral 1 denotes a laser light screen, 2 denotes a pixel unit, and 3 denotes a light absorption unit that is arranged around the pixel unit 2 and isolates the pixel unit 2 from each other.

  The light absorbing portion 3 is a black plastic plate formed by a mold and having a concave portion 4 as shown in FIG. 1B at a pixel portion forming portion. The pixel portion 2 is also a plastic similar to the light absorbing portion 3. It is a material.

  By providing the pixel portion 2 made of a plastic material including a diffusing material for diffusing light in the concave portion (which may be a through-hole) 4 of the light absorber 3, the laser light screen of this embodiment can be obtained. . In the case of a through-hole, rear projection is possible.

  As a method of providing the pixel portion 2 in the concave portion 4, a method of applying a liquid plastic material for forming the pixel portion 2 to a plastic plate that is the light absorbing portion 3, filling the concave portion 4, and hardening, or the light absorbing portion 3. An appropriate method such as printing a liquid plastic material for forming the pixel portion 2 on the plastic plate by a screen printing method can be used.

  By scanning the laser light screen 1 formed in this way with a laser beam electrically turned on / off by an image signal from an appropriate laser projector, a required monochrome image can be displayed. . At this time, the laser light is diffused by the diffusing material of the pixel unit 2 and the luminance of the entire pixel unit is averaged, and the scattered light around the pixel unit is absorbed by the light absorption unit 3, so that there is no blur. An image can be displayed. In addition, a wide viewing angle can be obtained by diffusion of light.

  In addition, if the laser is modulated in accordance with the number of pixels on the screen, the number of pixels can be changed without degrading the image quality.

  The light absorbing portion may be formed of a flat plastic plate or a plastic film having no recess, and the pixel portion is formed by screen printing or the like. The light absorbing portion may be a metal plate or a metal film, and in this case, plating with good light absorption efficiency such as black is performed for light absorption.

  Further, the shape of the pixel portion may be circular as shown in FIG.

  Further, when the light absorbing portion is a plastic material, the loss of incident light can be prevented by enclosing each pixel portion with a reflecting material, compared to the case where only the light absorbing material is used. The light reflecting material can be composed of a metal thin film, and a bright screen can be realized.

  In addition, a wavelength conversion material that emits a second harmonic, for example, green light may be added to each pixel portion together with a diffusing material together with infrared laser light to convert the color of the laser light.

(Deformation)
A modification of the present embodiment will be described. In this embodiment, in order to prevent bleeding due to laser spot light, the pixels are optically blocked, and the laser spot light is confined within the pixel. If the laser spot light is confined in the pixel, the contrast is remarkably improved and the sharpness is improved.

  There are the following three methods for confining the laser spot light in the pixel.

  First, as in the present embodiment, there is a method of surrounding each pixel portion with a light absorbing material. A black material is generally used as the light absorbing material. Although it is a desirable material for making black look clear, light absorption requires a certain depth and width, and this is a problem of the aperture ratio, so care must be taken.

  Second, there is a method of surrounding each pixel portion with a reflective material. If each pixel portion is surrounded by a reflective material, the loss of incident light can be prevented as compared with the case where a light absorbing material is used. Since the light reflecting material can be composed of a metal thin film, the aperture ratio can be increased as compared with the case where the light absorbing material is used, and a bright screen can be realized in combination with the effect of reducing the loss.

  Thirdly, there is a method in which each pixel is constituted by small spheres or particles. Of the light incident on the sphere or particle, it is diffused and the path of the light is changed in all directions, but light below the reflection critical angle is reflected on the surface of the sphere or particle because of its refractive index with air. As a result, the bleeding incident on other spheres or particles is reduced.

  As described above, a screen free from bleeding for laser light can be realized by using or combining the three methods.

(Related technology)
The projector is characterized in that the number of pixels and the size of the screen can be freely changed unlike a display (plasma, electroluminescence, liquid crystal, cathode ray tube) in which the number of pixels and the size of the screen are fixed. In the mainstream liquid crystal projector, the size can be changed, but the number of pixels is basically not changed. It is only a pseudo change, and the image quality deteriorates. For example, if a liquid crystal display with 1024 * 738 pixels is set to a resolution of 800 * 600, the number of pixels is not an integer multiple or a fraction of an integer, and it can be easily confirmed on a liquid crystal display of a personal computer that characters cannot be drawn clearly. .

  If a single light source is sufficient, a compact and lightweight projector can be manufactured without using a vacuum on the display using the same principle as a television that emits an electron beam onto the surface of a cathode ray tube and emits phosphors on the surface of the tube. be able to. In the present invention, this is realized by devising the screen.

  A rear projection screen in which an image is viewed on the front surface by irradiating laser light from the back surface of the screen is possible, and a front projection screen is possible by attaching a light reflecting sheet to the back surface of the screen.

  You can also advertise by simply attaching a detachable rear projection screen to the store's glass show window. Images can be provided easily when needed without requiring any special refurbishment of glass windows.

  Also, if a front projection screen is pasted on a simple wall, it will be possible to easily project an image there. The screen can be a soft screen because, for example, silicone rubber is used as a structure, and a diffusing material or wavelength converting material can be added therein. Of course, it can be used for bumps or curved surfaces.

  FIG. 3 is an enlarged view showing a part of the “laser beam screen” according to the second embodiment. FIG. 3A shows an example in which the pixel portion is square, and FIG. 3B shows that the pixel portion is circular. (C) is an example of a pattern similar to that of TV. The R (red), G (green), and B (blue) pixel portions are arranged in a required two-dimensional pattern as shown in the figure. Since the screen for laser light of the present embodiment is basically configured in the same manner as in the first embodiment, the description of the first embodiment, its modification, etc. is cited, and detailed description thereof is omitted here.

  Each of the R, G, and B pixel portions generates white light by adding a material that generates white light upon incidence of blue, blue-violet, and ultraviolet laser light together with a diffusing material. This is realized by color conversion using blue filters. This is the same principle as a color liquid crystal display realized by a combination of a white backlight, a liquid crystal element, and a color filter.

  Alternatively, each of the R, G, and B pixel portions may be realized by a method of generating the three primary colors R, G, and B by adding a material that converts the wavelength of the incident laser light together with the diffusing material. .

In the human eye, even with light of the same power, the brightness varies depending on the wavelength. This is called specific visibility (see FIG. 4). Green light feels brightest and blue and red feel dark. Therefore, in consideration of this specific visibility, if the light quantity of each of the three primary colors of light on the screen is adjusted, the color reproducibility will be excellent. This can be realized by adjusting the amount of the wavelength converting material added together with the diffusing material. For example, the amount of wavelength conversion material for green pixels is small, and the amount of wavelength conversion material for blue and red pixels is increased. Alternatively, the amount can be adjusted by the size of the pixel portion that is the red, green, and blue light emitting portion. Good. For example, the red and blue pixel portions are large and the green pixel portion is small.

  As described above, according to this embodiment, the contrast is remarkably improved and a clear color image without blur can be displayed. In addition, a wide viewing angle can be obtained by diffusion of light.

The figure which shows the structure of Example 1. The figure which shows the example whose pixel part is circular The figure which shows the structure of Example 2. Diagram showing specific visibility

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser light screen 2 Pixel part 3 Light absorption part

Claims (6)

A method of manufacturing a laser light screen, wherein a pixel portion of a plastic material including a diffusion material for diffusing light is formed in the concave portion of a black plastic plate having a plurality of concave portions. In the manufacturing method of the screen for laser beams according to claim 1,
  The method for manufacturing a screen for laser light, wherein the plastic plate is molded by a mold. In the manufacturing method of the screen for laser beams according to claim 1 or 2,
  The method of manufacturing a laser light screen, wherein the pixel portion is formed by applying a liquid plastic material to the concave portion, filling and curing the liquid plastic material. In the manufacturing method of the screen for laser beams according to claim 1 or 2,
  The pixel portion is formed by printing a liquid plastic material in the concave portion by a screen printing method. A laser light screen, wherein a plurality of pixel portions made of a plastic material including a diffusing material for diffusing light are formed on a black plastic plate or a black plastic film by screen printing at intervals from each other. Production method. A laser beam characterized in that a plurality of pixel portions made of a plastic material including a diffusing material for diffusing light are formed on a black-plated metal plate or a black metal film by screen printing at intervals. Manufacturing method for a screen.