JPH05948Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a projector, and in particular, a projector that projects a small display body made of multiple pixels, such as a television screen, onto a large screen surface for viewing on a large screen. The present invention relates to a projector that aims to improve the image quality of projected images.

(Prior Art) It has been common practice in the past to project a display 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 using a projector so that the display can be viewed on a large screen. At this time, if the display is a color display such as a color cathode ray tube, it may be projected directly onto the screen, or red,
Three displays consisting of cathode ray tubes with the three primary colors of green and blue are overlaid and projected onto a screen to perform color synthesis and observation.

In addition, recently, displays such as liquid crystals, which are composed of a plurality of regularly arranged pixels with certain gaps, are projected onto a large screen for observation.

However, when a display such as a television screen is projected onto a large screen surface, scanning lines are projected, making it difficult to observe, and displays such as liquid crystal have gaps between each pixel, so the projected image on the screen surface is difficult to observe. There were drawbacks such as the graininess becoming noticeable and making it difficult to observe.

In order to improve these drawbacks, for example, it is possible to use a display body with an increased number of pixels such as scanning lines, or a display body with a pixel pitch that is not visible, but this is difficult in terms of system and manufacturing. Further, although it is possible to lower the projection magnification, the effect of large-screen observation is reduced.

(Problems to be solved by the invention) This invention projects a display object such as a television screen, which consists of a plurality of regularly arranged pixels with certain gaps, onto a large screen surface. The purpose of the present invention is to provide a projector that reduces the apparent graininess of a projected image during observation and enables good observation.

(Means for Solving the Problem) In a projector that projects a display body consisting of a plurality of pixels arranged with gaps between the pixels onto a screen surface using a projection lens, the display body and the projection A microlens group is arranged between the lens and an enlarged image of each pixel of the display body, and the area of the gap between each pixel of the projected image on the screen surface of the enlarged image is reduced. That's what I did.

(Embodiment) FIG. 1 is a schematic diagram of an optical system according to an embodiment of the present invention. In the figure, 1 is a light source, and 2 is a condenser system, which condenses the light beam from the light source 1. Reference numeral 3 denotes a display body made of a transmissive liquid crystal, which is made up of a plurality of regularly arranged pixels having a certain gap. The display body 3 is irradiated with the light beam from the condenser system 2, and at this time, the passing light beam is optically modulated. 4 is a projection lens, and 5 is a microlens group, which is arranged between the projection lens 4 and the display body 3, and forms an enlarged virtual image of each pixel of the display body 3 on the light source 1 side.

The projection lens 4 projects an enlarged virtual image of the display body 3 displayed by the microlens group 5 onto a large screen 6 based on light modulation of the liquid crystal.

FIG. 2 is an explanatory diagram showing the relationship between the microlens group 5 of FIG. 1 and the display body 3. As shown in the figure, the microlens group 5 includes a plurality of microlenses 5 having optical axes of the same pitch as the pitch of each pixel 11 of the display body 3.
0, and are arranged corresponding to each pixel 11 of the display body 3. As a result, an enlarged virtual image 12 of each pixel 11 of the display body 3 is formed on the light source 1 side. At this time, various optical conditions such as the focal length of each lens of the microlens group 5 and the distance between the microlens group 5 and the display body 3 are set so that the enlarged virtual image 12 has a magnification that reduces the gap between each pixel. is set.

For example, if the magnification of the enlarged virtual image by the microlens group 5 is set so that there is no apparent gap between each pixel, the projected image on the screen 6 will be a completely continuous image. Also, if the magnification is smaller than this, a slight gap will remain in the projected image on the 6th screen, and if the magnification is higher than this, the projected image on the 6th screen will be in a state where each pixel partially overlaps, but in either case. Even if the projection image is 6, it is possible to observe the projected image on the screen 6 with reduced graininess.

In this embodiment, when the display body 3 is a cathode ray tube having a scanning line, the minute lens group 5 is a lenticular lens in which a plurality of cylindrical lenses are arranged in parallel to form an enlarged virtual image only in a direction orthogonal to the scanning line. In addition, when the display body 3 is composed of a matrix of pixels such as liquid crystal, it is preferable to use fly's eye lenses arranged in a matrix corresponding to each pixel.

Note that the same effect as described above can be obtained even if an enlarged virtual image is formed on the projection lens 4 side instead of the enlarged virtual image of the display body 3 by the microlens group 5.

(Effect of the invention) According to the invention, by arranging a microlens group of a predetermined shape at a predetermined position in the projection optical path, a display body consisting of a plurality of regularly arranged pixels with a certain gap is formed. By reducing the gap between each pixel on a large screen surface, it is possible to achieve a projector that reduces the graininess of the projected image and allows for better viewing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an optical system according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a portion of FIG. 1. In the figure, 1 is a light source, 2 is a condenser system, 3 is a display body, 4 is a projection lens, 5 is a microlens group, 6 is a screen surface, 11 is a pixel, and 12 is an enlarged virtual image of the pixel 11.

Claims (1)

[Claims for Utility Model Registration] (1) In a projector that projects a display body consisting of a plurality of pixels arranged with gaps between the pixels onto a screen surface using a projection lens, the display body and the A microlens group is arranged between the projection lens and an enlarged image of each pixel of the display body, so that the area of the gap between each pixel of the projected image on the screen surface of the enlarged image is reduced. A projector characterized by: (2) The projector according to claim 1, wherein the microlens group is a lenticular lens or a fly's eye lens.