JPS6294818A - Color image playback method - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] <Industrial Application Field> The disclosed technology is used in a projection image display method for slides, liquid crystal televisions, etc., in which images separated into the three primary colors of green, blue, and red are superimposed and projected onto a screen. It belongs to the field of separation and synthesis technology for optical systems that produce color images with turbulence.

Summary of the gist> Therefore, the present invention converts white light from a light source into green, blue, and blue lights in advance.
Color image reproduction that separates light into the three primary colors of red, transmits each of these lights through a monochrome image display device such as a slide or LCD TV, and focuses each light to create a colored image on a screen. This invention relates to a method, in particular, the white light is separated and reflected into three primary color lights through a dichroic mirror that reflects at least two of green, blue, and red, and depending on the design, the final reflection is performed by a total reflection mirror. Then, the light is collected by a corresponding dichroic mirror, or a dichroic mirror and a total reflection mirror, so that the optical efficiency can be improved and the light can be focused on a screen and displayed as a color image. This invention relates to a color image reproduction method.

<Prior Art> As is well known, various technologies have been developed for transmitting white light through a monochrome image display element such as a slide or a liquid crystal television and enlarging it on a screen. If the image is displayed on a screen using a monochrome image display element with fine pixels, technology has been developed to enlarge the image on the screen. Generally, white light from a light source is separated into red, blue, and green (hereinafter abbreviated as R, B, and G) using a color filter, and each light is transmitted through a monochrome image display element and focused on a screen to form an image. That's what I was doing.

That is, as shown in FIG. 3, the white light from the three white light sources 1.1.1 is passed through a condenser lens 2.2.2 to a filter 3 for R, a filter 3' for B, and a filter 3 for G. ', and separates the three primary color lights of R and 81G, respectively, into a monochrome image display element, for example, an image display element 6.6', 6' in which polarizing panels 5.5 are attached to the front and rear of a well-known liquid crystal panel 4. The R, B, and G images are transmitted through a projection lens 7, 7, and 7, and are overlapped onto a screen 8 to be formed and displayed.

〈Problems to be solved by the invention〉 However, in spite of the fact that the reproduction method of conventional nuclide technology, which converts a monochrome image into color and creates an image on a screen, requires three light sources and a large amount of power. ,
The light energy absorption rate of the filters 3, 3', and 3M for each of R, B, and G is large, and the brightness of the image formed on the screen 8 becomes dark. In order to accurately overlap each image on the screen 8, it is difficult to align the optical axes, color shift is likely to occur, and the control and management of the apparatus is complicated.

Moreover, it also has the disadvantage that it requires a lot of electricity and the running costs for maintenance, inspection, etc. become high, making it uneconomical.

The purpose of this invention is to solve the problem of colorization of images by monochrome image display elements based on the above-mentioned prior art, and to solve the problem by reflecting only light of a specific color and passing light of other colors. By skillfully utilizing dichroic mirrors that do not absorb thermal energy,
By making full use of the advantages of using a monochrome image display element with fine pixels, there is little light loss, and by using a simple method that does not require alignment of the optical axis, it is advantageous in the field of image creation technology used in the information industry. The purpose of this invention is to provide a method for reproducing color images.

<Means/effects for solving the problems> In order to solve the above-mentioned problems, the structure of the present invention, which is based on the above-mentioned claims, is to convert white light from one white light source into R. , B, G, and then through another dichroic mirror to obtain R,
B.

The three primary color lights of G are separated, each passes through an image display device such as a monochrome slide or an image on a liquid crystal panel, is reflected by a corresponding dichroic mirror, and is sequentially focused to create an overlapping image on a screen. By making the distances of the image display elements from the projection lens the same, automatic optical axis alignment becomes possible, and images can be efficiently colored and reproduced without absorbing almost any thermal energy. Therefore, technical measures have been taken to reduce costs by using a total reflection mirror for one primary color light for the final reflection.

<Embodiment - Configuration> Next, an embodiment of the present invention will be described below based on FIG. 1.2. Note that the same parts as in FIG. 3 will be explained using the same reference numerals.

In the embodiment shown in FIG. 1, the white light emitted from the light source 1 is absorbed by the cold mirror 9, while the remaining light is reflected and condensed into parallel light by the condensing lens 2.2'. Infrared rays are removed by an infrared absorption filter 10, and three dichroic mirrors 11.1
1' and 11'.

The nuclide dichroic mirror is well known and has the property of reflecting only specific primary color light and transmitting other primary color light, and has extremely high transmittance and extremely low heat absorption performance. It is.

Therefore, in this embodiment, the first dichroic mirror 11 reflects only R, transmits B and G,
The second dichroic mirror 11' reflects only B of the transmitted B and G, and the last transmitted G is reflected by the last dichroic mirror 11', and the corresponding dichroic mirrors 11.11 ', i
t', but in the meantime, in this embodiment, the liquid crystal panel 4 composed of a large number of fine pixels
The image display elements 6.6', 6I of a monochrome liquid crystal television with polarizing plates 5.5 attached to the front and rear of the screen are electrically connected to an image creation control device (not shown) to create a moving image. ing.

Then, each of the corresponding subsequent dichroic mirrors 11.
11' and 11'' are incident on each image display element 6.6'
, 6' and RlB, G having moving image information are the subsequent dichroic mirrors 11, 11', 11".
However, R is reflected by the first dichroic mirror 11 and passes through the second dichroic mirror 11', where it is condensed with B, which is reflected by the second dichroic mirror 11'. The light enters the third dichroic mirror 11' and is condensed together with the G reflected by the third dichroic mirror 111, and is overlapped by the projection lens 7 onto the screen 8 to produce a color image of R, B, and G. Create an image.

From the condensing lens 7, each image display element 6.6',
Since the distance 6' is kept constant, no adjustment of the optical axis is required, and a clear color image is formed on the screen 8.

Embodiment - Effect> In the above configuration, the white light emitted from the light source 1 is reflected by the cold mirror 9, and is transmitted to each dichroic mirror 11.11', 11'' via the condenser lens 2.2'.
Thermal infrared rays are removed by the infrared absorbing filter 10 in the process of being incident on the infrared rays, and R1B and G are reflected respectively.
In the process of being incident on the monochrome video image display element 6.6'6I, the image information is reflected by the subsequent dichroic mirrors 11.11' and 11'', and is condensed into the projection lens. 7, a clear color moving image of R, B, and G with the optical axes aligned is created on the screen 8.

In this process, the infrared absorption filter 1
In the optical system after 0, each dichroic mirror 1
1.11', 11' makes the visible light component of the incident light RB
Since it is decomposed into G and each of them is effectively used, there is little loss of light and little absorption of light, so there is no temperature rise, and the function of the liquid crystal panel 4 does not deteriorate, which may be caused by a decrease in function due to an increase in humidity.

Also, the light from one light source 1 is separated into the three primary colors of R, B, and G, and after passing through each image display element 6, 6', 6', is reflected by a dichroic mirror placed on the projection axis and projected in a straight line. Since the images are combined, there is no need to adjust the optical axis after projection, and therefore a color image of R, B, and G moving images with clear overlap is created on the screen 8.

In the above embodiment, since the third dichroic mirror 11' in the first stage only has the function of reflecting only G, as shown in the embodiment shown in FIG. A total reflection mirror 11'' is provided as the eye reflection mirror, and
A corresponding total reflection mirror 111 is provided for the first reflecting mirror in the latter stage so that only G is totally reflected, and the R and G lights are made incident on the first dichroic mirror 11 in the latter stage to be focused. The light B reflected by the dichroic mirror 11' is condensed to form colored moving image images R, B, and G on the screen 8 by the projection lens 7, thereby reducing the number of dichroic mirrors. It is possible to reduce costs.

It goes without saying that the actual FM aspect of the invention of this application is not limited to the above-mentioned embodiments. For example, as in the embodiment shown in FIG. By matching the values, the position of the liquid crystal panel 4 can be set arbitrarily.Also, the polarizing plate 5 can be installed at two locations, one at the incident light position from the light source 1 and the other near the projection lens 7, and used for both RBG and RBG. As shown in FIG. 4, it is also possible to use a reflective liquid crystal panel 4' instead of the transmissive liquid crystal panel.

In this case, since the back surface of the liquid crystal panel 4' can be directly cooled, heating of the liquid crystal can be suppressed.

Furthermore, the image display element may be not only a moving image on a liquid crystal television, but also a monochrome film for slides, and various embodiments may be adopted, such as providing an appropriate fluid cooling device for a white light source and a condensing lens. It is possible.

<Effects of the Invention> As described above, according to the present invention, basically, the advantages of low cost and fine pixels of a monochrome image display element are fully utilized, and a white light source can be used for R, B,
By separating the light into G and transmitting it through the monochrome image display element, an excellent effect is obtained in that the enlarged image on the screen is colored.

Furthermore, since the dichroic mirror for each of the three primary colors has little light absorption, there is little light loss, and heating of the device can be suppressed, resulting in the excellent effect that running costs such as cooling can be kept low.

Also, within one projection television, R and B of three images
, G can be condensed, and there is no need to align the optical axes on the screen, resulting in the excellent effect that a clear color image can be obtained.

[Brief explanation of drawings]

1 to 4 are detailed explanatory diagrams of the present invention. FIG. 1 is a schematic diagram of one embodiment, FIGS. 2.3.4 are schematic diagrams of other embodiments, and FIG. 5 is a conventional diagram. 1 is a schematic diagram of a color image reproduction method based on technology; FIG. 1...Light source,...White light, 8...Screen, 11.11', 11M...Dichroic mirror, 1
1″...Reflector

Claims (1)

[Claims] A method of reproducing color images by superimposing images separated into the three primary color lights of green, blue, and red on a screen, in which white light from a light source is captured using two or more dichroic mirrors arranged on its optical axis. After being reflected and separated into green, blue, and red light, each light is transmitted to the corresponding image display element, and then reflected and focused by two or more dichroic mirrors placed on the projection axis to form an image on the screen. A color image reproduction method characterized by: