JPS6330834A - Front screen - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a front screen that projects image light enlarged and projected by an image enlarging device, and more particularly to a front screen that prevents deterioration of contrast due to external light.

[Conventional technology]

A major problem with conventional front screens used in image enlarging devices is that the contrast of images on the screen deteriorates due to external light such as indoor illumination light that enters the screen other than image light. Therefore, as a way to solve this problem,
There is a screen described in Publication No. 35. This screen prevents the contrast of the image on the screen from deteriorating due to external light at the viewing position by changing the direction of reflection of image light and the direction of reflection of external light.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into account the distribution of reflected light of the image light in the reflective layer, and furthermore, the reflected light distribution characteristics are changed by changing the refractive index in two orthogonal directions of the base. There is also no consideration given to the distribution of light emitted from the substrate.As a result, some of the external light is directed towards the viewer's eye, resulting in a deterioration of contrast when the image on the screen is viewed from the viewer's eye. However, there was a problem that sufficient effects could not be obtained.

An object of the present invention is to provide a front screen that does not suffer from contrast deterioration due to external light.

[Means for solving problems]

The above purpose is to connect the screen base to a minute light absorption part and
The screen has a structure in which light reflecting surfaces are arranged alternately and continuously, and furthermore, in front of the screen, a convex cylindrical lens and a small light transmitting window that transmits the image light formed on the small reflecting surface in the viewing direction. This is achieved by installing a front seat consisting of alternating and continuous arrangement of

[Effect]

In the above configuration, the image light magnified by the projection lens becomes an aerial image formed before entering the convex cylindrical lens. The image point of this aerial image becomes the object point of the convex cylindrical lens. The image once formed at this object point is re-imaged at an image point which is a conjugate position with the object point by the lens action of the convex cylindrical lens.

Therefore, if a minute reflective surface is placed at this image forming position, the image on the minute reflective surface can be seen from the viewing position through the light transmission window. Note that the image created by the image light is inverted by the convex cylindrical lens, but since the vertical dimension of the minute reflective surface is sufficiently small compared to the vertical dimension of the entire screen, when viewing the screen from a jealous position, the pixels It's about the same amount as one piece, so it shouldn't be a problem.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

First, using FIG. 3, an example of the positional relationship between the image enlarging device, the screen, the jealous person, and the indoor lighting is explained. In Fig. 0, 5 is the screen, 6 is the image enlarging device, 7 is the indoor lighting, and 8 is the For a jealous person, 9 indicates image light, and 10 indicates external light (in this case, indoor lighting light).

When the jealous person 8 views the image on the screen 5 in such a positional relationship, in the conventional technology, contrast deterioration due to the external light 10 becomes a problem. The reason for this is that the external light 10 is reflected on the surface of the screen 50, and a part of the reflected light goes in the viewing direction together with the image light 9. Therefore, in the present invention, the screen has a structure in which the screen base has minute light absorbing parts and minute light reflecting surfaces arranged alternately and continuously,
Furthermore, by providing a front sheet with convex cylindrical lenses and small light transmitting windows arranged alternately and consecutively in front of the screen, the amount of external light reflected on the screen is reduced and the contrast of the image is reduced. prevents deterioration.

Next, the structure of a specific embodiment of the front screen according to the present invention will be described with reference to FIG. FIG. 1 is a longitudinal cross-sectional view of the embodiment, in which minute light absorption parts 1 and minute reflection surfaces 2 are arranged alternately and continuously, and in front of them, a convex cylindrical lens 3 and a light transmission window are arranged. 4 are arranged alternately and consecutively. Also, αl, b, b/, c, c
/, a, d, 4-! .

In Figure 0, where A-H indicates external light, for example, the image light is once formed into an image at the object point of the corresponding convex cylindrical lens 3, and by the convex cylindrical lens 6,
An image is formed on a minute reflective surface 2 provided at an image point that is a conjugate position with the object point. At this time, the image is reversed vertically, but since the vertical dimension of the minute reflective surface 2 is very small compared to the overall screen size, about one pixel, even if the individual images are reversed. The image light b' formed on the minute reflective surface 2, which does not matter when viewing the image of the entire screen, passes through the corresponding light transmission window 4 and is directed toward the viewing direction. b
The same mechanism applies to other image lights as well, and they become image lights directed in the jealous direction.

On the other hand, external light A, such as indoor illumination light, is irrelevant to direct imaging.

After B and the like enter the convex cylindrical lens 3, they are condensed onto the corresponding minute light absorbing portions 1 by the lens action, and are not reflected in the viewing direction.

Further, for the same reason, external light C, D, E, F, G, and H are not reflected in the viewing direction, so that the contrast of the image on the screen is not deteriorated by the external light.

FIG. 2 is a perspective view showing the screen of the above embodiment. In FIG. The front seat consists of The positional relationship between the screen base 12 and the front seat 13 is as follows:
It is determined by the holding frame 11 that holds both.

In the front screen according to the present invention described above, the contrast of the image on the screen is not affected by external light, and it is possible to obtain a good image even in a bright room.

〔Effect of the invention〕

According to the present invention, the enlarged image light that is normally incident on the screen is incident on the corresponding minute reflective surface by the convex cylindrical lens of the front sheet installed in front of the base,
The image can be seen from the viewing direction through the light transmission window, while external light such as indoor lighting enters the minute light absorption section and is absorbed by the convex cylindrical lens. Therefore, according to the present invention, the contrast of the image on the screen is not affected by external light, and good characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of a front screen according to the present invention, FIG. 2 is a perspective view of the embodiment, and FIG. 3 is a layout diagram showing the positional relationship between the image enlarging device and the screen. Explanation of symbols 1...Small light absorption part 2...Slight/j% reflection surface 3.
...Convex cylindrical lens 4...Light transmission window 11
...Holding frame 12...Screen base 13...Front seat No. 1 Flash/-Back 1 ＼ Special absorption shock 2 ・-zu 噸 ＼ Opposite top surface 3 - One convex cylinder F' prisoner reflex' 4. -Hiitsu's second home/-fbζノ)\A Otsup, 5 and 1llt-gi P2-～
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Eyebrow Achi

Claims (1)

[Claims] 1. A convex cylindrical lens installed on the front surface of a screen base in which minute light absorption parts and minute reflection surfaces are arranged alternately and continuously so that the minute reflection surfaces and the cylindrical axis are substantially parallel; 1. A front screen comprising a front sheet in which light transmitting windows are arranged alternately and continuously, each of which is configured to transmit image light formed on the minute reflective surface in a viewing direction.