JPH0850285A - Projection device - Google Patents

Abstract

PURPOSE:To reduce the area of a void part between respective picture elements on a large- sized screen surface and to realize excellent observation where the granularity of a projected picture is reduced by constituting the enlarged picture of the respective picture elements by a microlens group and projecting the enlarged picture of the respective picture elements by a projection optical system. CONSTITUTION:The microlens group 5 is arranged between the projection optical system 4 and a display part 3, and forms the enlarged virtual image of the respective picture elements on a display part 3 on a light source 1 side. The projection optical system 4 projects the enlarged virtual image by the microlens group 5 on the display part 3, which is displayed based on the optical modulation of liquid crystal, on the screen 6 surface. For example, when the magnification of the enlarged virtual image by the microlens group 5 is set so that the void part between the respective picture elements may not exist apparently, the projected picture on the screen 6 surface becomes the perfectly continuous picture. In the case the magnification is smaller than the set one, the slight void part is left on the projected picture on the screen 6 surface; and in the case the magnification is larger than it, the projected picture on the screen 6 surface is in,a state where the respective picture elements are partially overlapped; but the granularity of the projected picture on the screen 6 surface is reduced in any case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection device, and more particularly, to improving the image quality of a projected image when a small display unit including a plurality of pixels such as a television screen is projected on a large screen and observed on a large screen. The present invention relates to a projection device.

[0002]

2. Description of the Related Art Conventionally, it has often been practiced to project a display body such as a television screen, which is composed of a plurality of pixels, for example, a plurality of scanning lines, onto a large screen surface by a projector and observe it on a large screen. At this time, when the display unit is a color display unit such as a color cathode-ray tube, it may be projected directly on the screen surface, or three display units composed of red, green and blue primary color cathode-ray tubes may be superimposed on the screen surface. I observe it by projecting and synthesizing colors.

In addition, recently, it has been attempted to project a display portion such as a liquid crystal composed of a plurality of pixels regularly arranged with a certain void portion on a large screen surface for observation.

However, when a display portion such as a television screen is projected on a large screen surface, scanning lines are projected and it becomes difficult to observe, and since the display portion such as a liquid crystal has a space between each pixel, it is on the screen surface. However, there was a defect that the graininess of the projected image became remarkable and it became difficult to observe.

In order to improve these drawbacks, for example, a display section having an increased number of pixels such as scanning lines or a display section having a pixel pitch that is not visually recognized may be used, but this is difficult in terms of system and manufacturing. Moreover, it is sufficient to lower the projection magnification, but if so, the effect of large-screen observation is reduced.

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, a large screen is observed by projecting a display unit such as a television screen, which is composed of a plurality of pixels regularly arranged with a certain gap, onto a large screen surface. It is an object of the present invention to provide a projection device that can reduce the apparent graininess of a projected image when performing the observation and enables good observation.

[0007]

A projection device according to the present invention is a projection device for projecting a display portion having a plurality of pixels arranged with a gap between pixels by a projection optical system, wherein the display portion is The microlens group is arranged on the side of the projection optical system, the magnified image of each pixel is formed by the microlens group, and the magnified image of each pixel is projected by the projection optical system.

[0008]

1 is a schematic diagram of an optical system according to a first embodiment of the present invention. In the figure, 1 is a light source, and 2 is a condenser system, which collects the light flux from the light source 1. Reference numeral 3 denotes a display unit made of a transmissive liquid crystal, which is composed of a plurality of pixels which are regularly arranged with a certain gap. The display unit 3 is illuminated with the light flux from the condenser system 2, and the passing light flux is optically modulated at this time. 4 is a projection optical system, 5 is a microlens group, and the projection optical system 4 and the display unit 3
And an enlarged virtual image of each pixel of the display unit 3 is formed on the light source 1 side.

The projection optical system 4 projects a magnified virtual image displayed by the microlens group 5 of the display unit 3 on the surface of a large screen 6 based on the light modulation of the liquid crystal.

FIG. 2 is an explanatory view showing the relationship between the microlens group 5 and the display section 3 of FIG. As shown in the figure, the microlens group 5 is formed of a plurality of microlenses 50 having an optical axis having the same pitch as the pitch of each pixel 11 of the display unit 3, and corresponds to each pixel 11 of the display unit 3. Are arranged.
Thereby, the enlarged virtual image 12 of each pixel 11 of the display unit 3 is formed on the light source 1 side. At this time, the focal length of each lens of the microlens group 5 and the microlens group 5 are set so that the magnified virtual image 12 has a magnification that reduces the area of the void between each pixel.
And various optical conditions such as the distance between the display units 3 are set.

For example, if the magnification of the magnified virtual image by the minute lens group 5 is set so that the voids between the pixels are apparently eliminated, the projected image on the screen 6 becomes a completely continuous image. Further, if the magnification is smaller than this, a slight void portion remains in the projected image on the screen 6 surface, and if the magnification is large, each pixel of the projected image on the screen 6 surface partially overlaps. Screen 6 even if
Good observation is possible with reduced graininess of the projected image on the surface.

In the present embodiment, when the display unit 3 is a cathode ray tube having a scanning line as the minute lens group 5, a lenticular lens in which a plurality of cylindrical lenses are arranged in parallel so as to form a magnified virtual image only in a direction orthogonal to the direction. Is preferably used, and when the display unit 3 is composed of pixels in a matrix such as liquid crystal, it is preferable to use a fly-eye lens arranged in a matrix corresponding to each pixel.

Even if an enlarged real image is formed on the side of the projection optical system 4 instead of the enlarged virtual image of the display section 3 by the minute lens group 5, the same effect as described above can be obtained.

[0014]

According to the present invention, in a projection device for projecting a display section having a plurality of pixels arranged with a gap between pixels by a projection optical system, the projection optical system of the display section. Each of the pixels on the large screen surface by arranging a minute lens group on the side, forming an enlarged image of each pixel by the minute lens group, and projecting an enlarged image of each pixel by the projection optical system. Reduce the area of the space between
It is possible to achieve a projection device capable of good observation with reduced graininess of the projected image.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an optical system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a part of FIG.

[Explanation of symbols]

 1 Light Source 2 Condenser System 3 Display 4 Projection Optical System 5 Microlens Group 6 Screen Surface 11 Pixel 12 Pixel 11 Enlarged Virtual Image

Claims (4)

[Claims] 1. A projection device for projecting a display section having a plurality of pixels arranged with a gap between the pixels by a projection optical system, wherein a microlens group is provided on the projection optical system side of the display section. A projection device which is arranged, forms a magnified image of each pixel by the minute lens group, and projects a magnified image of each pixel by the projection optical system. 2. The projection device according to claim 1, wherein the enlarged image of the pixel is a virtual image. 3. The projection device according to claim 1, wherein the magnified image of the pixel is a real image. 4. The projection device according to claim 1, wherein the minute lens group is a lenticular lens or a fly-eye lens.