JPH0736118A - High-contrast image projecting device and high-contrast image projecting screen - Google Patents

Abstract

PURPOSE:To realize a high-contrast image projecting device capable of projecting an image with sufficient contrast even in a bright room by efficiently projecting an optical image projected from a set fixed direction. CONSTITUTION:Light projected from a projector and made incident from a direction shown by an arrow 14 is condensed by a lens array 11 and focused on or near a reflector 13. The condensed light is reflected by the reflector 13, transmitted through one lens out of the lens array 11 (a lens one under the lens on which the light is made incident) again, and projected in a direction shown by an arrow 15 (a main direction, and the light advances also in another direction, then it shows directivity). By projecting the optical video by a video projector projected from the fixed direction in the set direction, the contrast of the projected image is made high. This is because the light only from the direction of the projected optical video straight advances toward an observer and the light other than the above light does not straight advance toward the observer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image projection device and an image projection screen that project a video signal as a high-contrast image.

[0002]

2. Description of the Related Art It is common knowledge that a conventional image projection apparatus projects an image in a dark room. This is because the light intensity of the image projection device is low and the brightness of the image when projected onto the screen is low, and because the screen is white (the reflectance is high) and the image projected by a slight amount of outside light is whitish and the contrast is low. is there. Conventionally, improvements have been made to increase the projected brightness of an image projection device.

[0003]

However, the brightness of an ordinary room is still insufficient, and the contrast of an image projected in an ordinary room is still low, which is insufficient for a practical level.

The present invention solves the above problems and provides and provides an image projecting apparatus that allows an image projected in a room of general brightness to have a sufficient contrast. Another object of the present invention is to realize and provide a screen capable of obtaining a sufficient contrast when an image is projected by a general image projector.

[0005]

In order to solve the above problems, the present invention provides a projection means for projecting an input image signal as light, a light collection means for collecting a certain amount of light, and a light collection means. A reflecting means for reflecting the reflected light in a prescribed direction and a lens means for projecting the light reflected by the reflecting means in the prescribed direction, and a light image projected from a fixed direction in the prescribed direction. It is a high-contrast image projection device characterized by projection and a high-contrast image projection screen configured by means other than the projection means.

[0006]

According to the present invention, a light image projected from a predetermined fixed direction can be efficiently projected in a predetermined direction, and most of light incident from other directions is absorbed. However, it is not radiated in the direction in which the image is projected.

Therefore, an image projected from a predetermined fixed direction can be observed with sufficient contrast even if outside light is present in the room without causing the black portion to be dull, and even in a bright room. A high-contrast image projection device and a high-contrast image projection screen that can project an image with sufficient contrast can be realized.

[0008]

EXAMPLES A high-contrast image projection device and a high-contrast image projection screen according to examples of the present invention will be described below.
Hereinafter, description will be given with reference to the drawings.

(Embodiment 1) FIG. 1 shows the configuration of the apparatus. In the figure, 1 is a projection means for projecting an image signal as light,
2 is a screen means for reflecting the projected image in a predetermined direction. Although 3 and 4 are not image projection devices, 3
Is a room in which the image projection device is installed, and 4 is the illumination of the room. Reference numerals 5 and 6 indicate directions in which the optical image is projected. The image signal is projected onto the screen 2 by the projection means 1 composed of a CRT or liquid crystal, a lamp and a projection lens, and the light of the image signal reflected by each part of the screen is projected in the direction of the observer. A screen 2 viewed from the direction of the observer is shown in FIG. 2 (hereinafter, a light image projected on the screen and reflected from the screen is referred to as “projected”). The surface of the screen is composed of a small lens array as shown in FIG. 2 (b), and each lens has a structure in the vertical direction AA 'cross section and BB' cross section shown in FIG.

FIG. 3 (a) is a lateral view of a cross section taken along the line AA 'in the vertical direction. Reference numeral 11 denotes an acrylic resin forming a lens array (any material that can be easily processed and transmits light well).
Reference numeral 12 is a light absorber that absorbs light well, and 13 is a light reflector that reflects light. The light projected from the projector entering from the direction indicated by the arrow 14 is condensed by the lens array 11 and focused on or near the reflector 13. The condensed light is reflected by the reflector 13 and again passes through one of the lens arrays 11 (the lens immediately below the incident lens), and then passes in the direction indicated by the arrow 15 (main direction and other directions). It is also directed to, and will later show directional). A cross section in the horizontal direction BB ′ is shown in FIG. The difference from the vertical direction is that the radius of curvature of the lens array 21 is small and that the light absorber 1
The width of 2 is smaller than that in the vertical direction, and the width of the light reflector 13 is increased. This is to widen the directivity of projected light in the horizontal direction with respect to the vertical direction. The main directions of the light projected with respect to the light incident from the direction indicated by the arrow 16 are indicated by arrows 17 to 19. Further, by making the shape of the light reflector 13 a convex surface as shown by 13b, it is possible to further widen the directivity on which light is projected. Although there is a characteristic difference in directivity, even if the radius of curvature of the lens array 22 is increased as shown in FIG. Here, the light reflectors 13 and 13b do not have to be limited to those that hardly diffuse light such as mirrors, and if a substance that has a large amount of diffusion such as white paper is used, the ridges and valleys of the directional characteristics will be smooth, The directional characteristics are also widened. The main direction of the projected light is indicated by arrow 23. FIG. 4 shows an outline of the directivity in which light is reflected and projected by the screen portion of the present invention described above. FIG. 4A shows the directivity in the vertical direction.
(B) is the directivity in the horizontal direction. The center of the directivity in the vertical direction may be set at the height of human eyes, and the directivity may be relatively narrow. The horizontal directivity assumes a plurality of observers and has a relatively wide directivity. By determining the shapes of the lens arrays 11, 21, 22, the light absorber 12, and the light reflector 13 as described above, only the light projected from a certain direction is reflected by the light reflector 13 and the direction of the observer. Light coming from other directions,
A structure which is absorbed by the light absorber 12 and does not face the observer can be realized.

As described above, according to the present invention, it is possible to increase the contrast of the projected image by projecting the optical image of the video projector projected from one direction in the predetermined direction where the observer is present. Become. This is because the light only from the direction of the projected optical image goes straight to the observer, and the other light (such as the illumination light of the room) does not go straight to the observer. Therefore, in the case of the present invention, even under the condition that the conventional room lighting is bright and the image cannot be observed with sufficient contrast even when the light image is projected,
The illumination light does not reflect on the screen and enter the eyes of the observer, and even in a bright room, with sufficient contrast,
It becomes possible to observe an image projected on a screen as an optical image, and its practical value is very high.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In the second embodiment of the present invention, the characteristic improvement of the screen means will be described. In particular, a method of increasing the probability of absorption of light incident from a direction other than the direction in which the image is projected to suppress the phenomenon in which the dark portion of the projected image becomes white and the projected optical image are efficiently observed by the observer. A method of projecting in the direction will be described.

First, a method of increasing the probability that light incident from a direction other than the direction in which the image is projected is absorbed to suppress the phenomenon that the dark portion of the projected image becomes white is described.
The specific configuration of the screen means is shown in FIG. This figure shows the AA 'cross section (vertical direction) of FIG. 2B, and corresponds to FIG. 3A of the first embodiment. Figure 5
In (a), 31a is an acrylic resin (which may be a material that is easy to process and transmits light well) 32a and 34a are light absorbers that absorb light well, and 33a is light that reflects light. It is a reflector. The difference from the first embodiment is the light absorber 34a of
4a absorbs light coming from directions other than the projection direction of the projector. In the case where the light absorber 34a is not provided, of the light incident from directions other than the projection direction of the projector,
Light that happens to be incident from the direction in which it reaches the light reflector 33a is reflected and is not absorbed again and is again absorbed by the lens array 31.
emitted from a. Therefore, the screen itself is not black, the black part of the image is made to appear white, and the entire screen becomes whitish, which causes deterioration of image quality. Light absorber 34
The light a is incident from a direction other than the projection direction of the projector, which causes the above-described image quality deterioration, and absorbs the light traveling in the direction of the light reflector 33a.

As described above, the light absorber 34a absorbs unnecessary light that enters from a direction other than the direction of the projector and causes deterioration of image quality, and suppresses a phenomenon in which a dark portion of a projected image becomes white. .

Next, a method of efficiently projecting the projected optical image in the direction of the observer will be described. This is the principal axis of the projected light (center of directivity) when the projected light is projected in the direction of the observer on any part of the screen.
Is directed toward the observer. This configuration is shown in FIG.
It shows in (b). The figure shows a cross section taken along the line AA 'shown in FIG. 2 (b), and shows the configuration of the lower part of FIG. 2 (a). The lower the screen is, the larger the elevation angle of the light incident from the projector is, and the direction in which the light is projected in the direction of the observer needs to be higher than horizontal. The light reflector 33b is angled from the back surface of the screen so as to satisfy these conditions. In this case, the direction is set to reflect light above horizontal. In addition, the shape of the light absorber 34b is deformed according to the direction of light so that it is not included in the optical path of the light projected from the projector, and the light is not absorbed. In order to project from each portion of the wide screen in the direction of the observer, the curvature of the lens array 31,
It is necessary to change the distance from the lens array 31 to the reflector 33 (thickness of the lens array), the pitch and direction of the reflector 33, and the shape of the light absorber 34 little by little according to each place on the screen.

Thus, in each part of the screen,
By changing the direction and shape of the reflector 33b and the absorber 34b, the optical image projected from the projector is efficiently projected in the direction of the observer, and a brighter image can be observed. Increasing the brightness of the white peak of the image increases the white-to-black ratio (contrast) of the image, making it possible to observe an image with higher contrast even in a bright room, and can be used at home It is possible to realize the basic technology for realizing a large screen TV.

As described above, in the second embodiment of the present invention, the structure of the screen is devised so that the light emitted from the place other than the projector is absorbed inside the screen,
It is possible to have a structure that does not project from the screen, and at the same time, for the light projected from the direction of the projector, a large part of it can be projected to the direction of the observer, and even in a bright room, the image signal is converted into an optical image. It can be projected and observed as an image with sufficient contrast, that is, the basic technology for realizing a large-screen TV or the like that can be used at home can be realized, and its practical value is high.

The screen structure shown in FIG. 5 (b) may be configured as shown in FIG. 6 (a). The difference from FIG. 5B is that the light reflector 33b is bent backward to form a concave mirror, and the light absorber 34b is changed to the structure indicated by 38.
To widen the directional characteristics of the projected light, the characteristics of the lens 36 and the reflecting mirror 37 are changed so that the lens 39 and the reflecting mirror 40 are formed as shown in FIG. 6B, and the light absorbers 41 and 42 are used.
It is also possible to do like this. The light absorbers 41, 4
The shapes of 2, 38, and 34 need not be limited to those shown here, and may be any shape that secures the light path shown in each drawing and blocks the other light paths. For example, the wedge shape may be a flat plate.

Further, in the present invention, in order to collect the projected light in the direction of the observer, the relative position between the light reflecting direction of the light reflector 33 and the lens array and the thickness of the resin forming the lens array are set as follows. Although it is changed in each part of the screen, the screen itself may be curved so that the light is collected in the direction of the observer.

Further, in the present invention, the light reflector is arranged in the light absorber in an island shape, but it is clear that even if it is linear, the performance is improved as compared with the conventional screen. include.

Similarly, even if the lens array is a semi-cylindrical lens, the performance is obviously improved as compared with the conventional screen, and this is also included in the present invention.

[0022]

As described above, according to the present invention, a projected image with high contrast can be observed even in a normally illuminated bright room without using a special video projection means with a very high light amount. , Its practical value is very high.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a first embodiment of a high-contrast image projector according to the present invention.

FIG. 2 is a diagram showing an outline of a screen shape of a high-contrast image projection device of the present invention.

FIG. 3 is a diagram showing a configuration of a screen of the high-contrast image projector according to the present invention.

FIG. 4 is a characteristic diagram showing directional characteristics of a screen of the high-contrast image projector according to the present invention.

FIG. 5 is a diagram showing the configuration of a second embodiment of the screen of the high-contrast image projection device of the present invention.

FIG. 6 is a diagram showing a third configuration of the screen of the high-contrast image projector according to the present invention.

[Explanation of symbols]

1, ... Video projection means 2, ... Screen means 3, ... Room 4, ... Illumination 11, 21, 22, 31, 36, 39, ... Lens array 12, 32, 34, 38, 41, 42 .., light absorbers 13, 33, .. light reflectors 37, 40 .., concave mirror array

Claims (10)

[Claims] 1. A projection means for projecting an input image signal as light, a light collecting means for collecting the light, a reflecting means for reflecting the collected light in a predetermined direction, and a reflecting means for reflecting the light. A high-contrast image projection device comprising: a lens means for projecting the projected light in a defined direction, and projecting the projected image in the defined direction. 2. The same condensing means and lens means use the same optical means, and the reflecting means is divided into a portion having a high reflectance and a portion having a low reflectance, for the light projected from a specific direction. The high-contrast image projection device according to claim 1, further comprising a reflective screen having a high reflectance and a low reflectance in the other directions. 3. The distribution of the high reflectance portion of the reflecting means is smaller in the vertical direction than in the low reflectance portion, and is larger in the horizontal direction than in the vertical direction. High contrast image projector. 4. The high-contrast image projection device according to claim 2, wherein a portion of the reflecting means having a high reflectance is substantially flat in the vertical direction and has a convex surface in the horizontal direction. 5. The high-contrast image projector according to claim 1, wherein the light collecting means and the lens means have a vertical light collecting angle different from a horizontal light collecting angle. 6. A condensing means for condensing a plurality of lights, a reflecting means for reflecting the condensed light in a predetermined direction, and a lens for projecting the light reflected by the reflecting portion in the predetermined direction. A high-contrast image projection screen comprising means for projecting a projected image in a defined direction. 7. The condensing means and the lens means use the same optical means, and the reflecting means is partially divided into a portion having a high reflectance and a portion having a low reflectance, and with respect to light projected from a specific direction. 7. The high-contrast image projection screen according to claim 6, which has a high reflectance and a low reflectance in the other directions. 8. The distribution of the high reflectance portion of the reflecting means is smaller in the vertical direction than in the low reflectance portion, and is higher in the horizontal direction than in the vertical direction. High contrast image projection screen. 9. The high-contrast image projection screen according to claim 7, wherein the high-reflectance portion of the reflecting means is substantially flat in the vertical direction and convex in the horizontal direction. 10. The high-contrast image projection screen according to claim 6, wherein the light collecting means and the lens means have a vertical light collecting angle different from a horizontal light collecting angle.