JPH02201485A - Method and device for liquid crystal picture projection - Google Patents

Abstract

PURPOSE:To form a well-balanced picture of satisfactory contrast by making equal the polarizing direction of projected light carrying picture information from a projection lense. CONSTITUTION:A light source 3 such as a halogen lamp is provided closer to one side of a housing 2 made of rigid resin, etc., and the projection lense 6 is provided closer to the other side with respect to a screen 13. Liquid crystal panels 9, 9' and 9'', are additionally provided with polarizing panel in such a way that polarizing direction of beam transmitting the projection lense 6 can be setted 45 deg., the intermediate of a longitudinal wave and a transverse wave, according to the number of beams reflected by reflecting plates. The light transmitting the lense 6 and carrying picture information is setted in one polarizing direction. Therefore, a well-balanced picture with the satisfactory contrast can be formed on the screen without any flicker.

Description

[Detailed Description of the Invention] <Industrial Application Field> The disclosed technology enlarges images such as color images formed on a liquid crystal panel on a screen mounted on a wall inside a room or in a transportation facility such as a train or airplane. A method and apparatus for projecting images, comprising a housing made of synthetic resin or the like, in which a light source such as a halogen lamp is provided on one side, and a projection lens for a screen is provided on the other side; A method in which a predetermined number of liquid crystal panels electrically connected to an electronic drive device for image formation are interposed between the lens and the light source, and the image formed on the liquid crystal panel is enlarged and projected on a screen; This invention relates to a device, and in particular, a liquid crystal image projection method in which the polarization directions of projection light carrying image information from a projection lens to a screen are aligned in the same direction, and a device directly used in the method. This invention relates to.

<Conventional technology> As is well known, modern society has transitioned from a material society to an energy society and now to an information society, and in particular, the tremendous development of photoelectric technology has made it possible to instantly transmit and process information not only over short distances but also over long distances. Information processing using such photoelectric technology is becoming widespread, not only in civil society but also in industrial society.

There are many so-called on-devices used in such information processing, which are now being used not only for business purposes but also for private education and entertainment.

Information processing using photoelectric technology has two trends, from the early cathode ray tube method to the liquid crystal method, which has been rapidly developed in recent years.The former is a type of face-to-face method that requires only one person or a few people However, with the exception of special exceptions such as so-called video projectors, it is not possible to convey information to an unspecified number of viewers.
Moreover, the unit device is large-scale, heavy, and has the disadvantages that not only initial installation but also operation and maintenance inspection are cumbersome, whereas the liquid crystal type is simply small and personal. Not only the benefits,
Due to its light transparency, it can be enlarged and projected onto the screen via a projection lens, and has the advantage of simultaneously transmitting and processing a large amount of information to many viewers.In addition, the polarized image is projected onto the screen using the attached polarizing panel. Research and development is still being carried out from various angles due to the advantages such as being able to form color three-dimensional images, etc. From this point of view, the cathode ray tube method and the liquid crystal method are becoming polarized. They are on the verge of developing and reversing each other by taking advantage of their respective strengths and advantages.

As mentioned above, the liquid crystal system is lightweight and compact, and can enlarge and project an image, and depending on the design, can be superimposed on the screen to form a color image of your choice, making it suitable for a variety of uses. is being planned.

<Problems to be Solved by the Invention> Therefore, a liquid crystal panel is indispensable in a nuclide liquid crystal type information processing device, and is electrically connected to a certain electronic drive device to form a monochrome image or a color image. However, in liquid crystal panels of this type, the polarizing panels attached to the front and back surfaces are generally constructed so that their polarization directions are the same when viewed from the main body of each liquid crystal panel. Ta.

As mentioned above, since liquid crystal information processing devices are small and compact, when projecting the image formed on the liquid crystal panel onto the screen, it is generally necessary to enlarge and project it through a projection lens. , a liquid crystal panel that individually forms images in three colors, such as red (R), blue (B), and green (G), in order to prevent flickering on the screen when enlarging and projecting color images, etc. In order to project these on the screen, a total reflection mirror or a half mirror is used as a reflection plate to superimpose each transmitted light on the screen.
However, as mentioned above, the polarizing panels attached to each liquid crystal panel body all have the same polarization direction when viewed from each liquid crystal panel, so the transmitted light projected from the projection lens onto the screen is Since the polarization directions are different, there is an inconvenience that, for example, it is not possible to form an invisible image on the screen that can only be seen by a person wearing polarized glasses.

<Object of the Invention> The object of the invention of this application is to solve the problem of image projection using a liquid crystal panel in which all the polarizing panel directions are in the same direction when viewed from the liquid crystal panel based on the above-mentioned prior art, and to solve the problem of total reflection. When forming an image using transmitted light that is superimposed on a screen through a projection lens using a reflecting plate such as a mirror or dichroic mirror, the polarization direction of the transmitted light is all aligned in the same direction to form an image with a well-balanced and improved contrast. It is an object of the present invention to provide an excellent liquid crystal image projection method and apparatus that can also form invisible images and benefit the field of image forming technology utilization in the information industry.

<Means/effects for solving the problem> In order to solve the above-mentioned problem, the structure of the invention of this application, which is summarized in the above-mentioned claims, is to solve the above-mentioned problem. A light source such as a halogen lamp is provided on the screen, a projection lens is provided on the other side of the screen, and a liquid crystal panel connected to an electronic drive device is installed between the light source and the projection lens in red (R), blue (B), and green. (G) etc., a predetermined number of liquid crystal panels are arranged in a predetermined posture such as vertical or horizontal, and reflective plates such as total reflection mirrors or dichroic mirrors are arranged in front and behind them, and a polarizing panel is attached to each liquid crystal panel. The polarization direction is intermediate between P waves (longitudinal waves) and S waves (transverse waves), for example, at a 45° angle, so that the polarization direction of the light that passes through the projection lens is aligned in the same direction depending on the number of times it is reflected on the reflector. Furthermore, by arranging one polarizing panel on the light source side and the projection lens side instead of attaching a polarizing panel to the liquid crystal panel, transmitted light carrying image information transmitted from the lens can be Depending on the design, a polarizing panel on the projection lens side may be attached to the front of the screen.
A technical means that ensures that the polarization direction of each transmitted image light is aligned to form a well-balanced and uniform image with good contrast on the screen, and in some cases it is also possible to form an invisible image. Write down what you learned.

<Embodiments> Next, embodiments of the invention of this application will be described below with reference to the drawings.

It should be noted that the same parts will be described with the same reference numerals throughout all the embodiments.

In the embodiment shown in FIG. 1, numeral 1 is a liquid crystal image projecting device which forms one of the main points of the invention of this application, and a rectangular housing 2 made of a predetermined material is located at the upper side of the housing 2. A halogen lamp 3 is used as a light source, and a total reflection mirror 4 and a condensing lens 5 are provided above and below the halogen lamp 3, and a projection lens 6 is provided at the upper part of the housing 2 on the other side facing a screen (not shown). It is provided.

A total reflection mirror 7. is provided on both sides of the lower side of the housing 2.
7' is installed at an angle of 45° with an open shape when viewed from the side.
Between them is the well-known dichroic mirror 81.82
are placed at equal intervals.

On the upper side of the housing 2, two dichroic mirrors 84 and 85 are installed between the light source 3 and the projection lens 6.
, and a total reflection mirror 7' are provided parallel to each other at an angle of 45 degrees, and in positions and orientations facing the dichroic mirrors 81, 82 and the total reflection mirror 7'.

Therefore, the light from the light source 3 is transmitted to the dichroic mirror 8
1.82, a total reflection mirror 1', a dichroic mirror 84.85, and a total reflection mirror 7', the light is converted into one transmitted light near the projection lens 6, and is projected onto a screen in a superimposed manner.

Therefore, in the upper part of the housing 2, there is a total reflection mirror 1.
A green (G) liquid crystal panel 9 is installed vertically between the dichroic mirror 84 and the dichroic mirror 84, and a blue (B) liquid crystal panel 9' is installed horizontally between the dichroic mirrors 84 and 85. Also, on the lower side of the housing 2, a dichroic mirror 82 and a total reflection mirror 7' are installed.
A liquid crystal panel 9'' for red (R) is provided in a vertical position between them.

Therefore, in the invention of this application, each liquid crystal panel 9.9
The first liquid crystal panel is attached to the polarizing panels attached to the projector lens 6' and 9'' for S waves (transverse waves) that are easily reflected by the dichroic mirror so that the polarization direction of the light transmitted from the projection lens 6 is aligned in the same direction. 9 is S+45°,
For the second liquid crystal panel 9', 5-
45°, and the third liquid crystal panel 9'' has a polarization direction of 2S+45° due to double reflection.

Note that 10 is a predetermined electronic drive device, and a liquid crystal panel 9.
A color image such as a predetermined television image is formed on the LCD panel 9' and 9''.The green (G) and blue (B ), red (R>
Color formation is performed using a well-known black and white liquid crystal panel and a dichroic mirror.

In the above configuration, the liquid crystal panel 9 is connected to the electronic drive device 10.
．． A predetermined television image or videotape image is formed on 9', 9'', and the light from the halogen lamp 3 passes through a condenser lens to a total reflection mirror 7, a dichroic mirror 81, 82,
The total reflection mirror 7' is reflected a predetermined number of times through the dichroic mirror 84, the dichroic mirror 84, and the dichroic mirror 85, and is transmitted to the liquid crystal panel 9.9'.
In the first liquid crystal panel 9, the polarizing panel 11 of the first liquid crystal panel 9 receives the image information formed on the
°Dichroic mirror 8 is left as it is
4.85 and passes through the projection lens 6.

In addition, since the second liquid crystal panel 9' is reflected by the dichroic mirror 84, its polarizing panel 11' has a polarization direction of 5-45 degrees with respect to the transverse wave S, so that it is reflected by the dichroic mirror 84 and the dichroic mirror 85 and the projection lens 6, it is aligned in the polarization direction of S+45°, and the third
Regarding the polarizing panel 9u, the total reflection mirror 7' and
Since it is reflected twice by the dichroic mirror 85, the polarizing panel 11'' has a polarization direction of S+45° for the transverse wave S, so that when it passes through the projection lens 6, the polarization direction is S+45°, and as a result, 1st, 2nd
, third liquid crystal panel 9, gr, get, the polarization direction of the light is all aligned in the same direction at S+45°, and is superimposed on a screen (not shown) to produce a well-balanced extremely well-balanced light. Contrast is possible.

In this case, if the screen is a polarizing screen, an extremely good projected image can be obtained.

Next, in the embodiment shown in FIG. 2, unlike the above-mentioned embodiment in which polarizing panels are attached to the front and back surfaces of the liquid crystal panels 9, 9'9'', no polarizing panels are attached to the liquid crystal panels, and a polarizing panel is attached to the bottom. Dichroic mirror 81 adjacent to side total reflection mirror 7
A polarizing panel 111 with a polarization direction of S+45° for the transverse wave S is interposed between the transverse wave S and the transverse wave S is placed in front of the projection lens 6.
This is an embodiment in which a polarizing panel 112 is interposed with the polarization direction of S + 45 degrees, and as a result, the transmitted light from the projection lens 6 is the transmitted light aligned in the same polarization direction of S + 45 degrees of the transverse wave S. The light is superimposed on the screen, so that a bright, clear, well-contrasted, and well-balanced image can be obtained as in the above-described embodiment.

Next, in the embodiment shown in FIG. 3, a polarizing panel 111 with a polarization direction of S+45° is installed between the total reflection mirror 7 on the lower side of the housing 2 and the dichroic mirror 81 next to it.
It is the same as in the above-mentioned embodiment that S+4 is inserted in front of the polarizing screen 13 for other polarizing panels.
This is an embodiment in which a polarizing panel 113 with a polarization direction of 5° is attached, and as a result, projection lights having the same polarization direction as in the above embodiment are visually recognized as being superimposed.

The embodiment shown in FIG. 4 has a polarizing panel 11 attached to the front surface of the polarizing screen 13 of the embodiment shown in FIG.
If the viewer 14 uses polarized glasses 15 instead of 3, a clear color image with good contrast and balance can be viewed. In this case, the image formed on the polarized screen 13 is an invisible image. Therefore, it has the advantage that only the viewer using the polarized glasses 15 can see it, and other people cannot see it.

It should be noted that the embodiments of the invention of this application are of course not limited to the above-mentioned embodiments; for example, various embodiments such as bouncing and installing appropriate cooling IahM etc. for the liquid crystal panel can be adopted. I'll go.

Furthermore, in terms of design changes, it is also possible to use a PLZ display element or the like in place of the liquid crystal panel.

<Effects of the Invention> As described above, the invention of this application has a liquid crystal panel electrically connected to an electronic drive device, and images formed on the liquid crystal panel etc. are illuminated by light from a light source such as a halogen lamp. For example, when multiple images of different colors are reflected a predetermined number of times using a dichroic mirror or the like and are superimposed, the light projected from the projection lens onto the screen is By arranging all the polarization directions in the same direction, there is no imbalance in the superimposed transmitted light, and an excellent effect is achieved in that images such as clear color images with good contrast can be visually recognized.

Therefore, invisible images, etc. can be projected, and only viewers using polarized glasses (1') with polarized filters can see the 1,000 tatami images on the screen, while other people can read or use the bright screen without images. The effect is that there is no hindrance to viewing the scenery outside the train window.

In addition, polarizing panels attached to the front and back surfaces of the liquid crystal panel are installed.
Because it can be omitted depending on ", the device structure) old becomes the inside of the cylinder,
It also has the advantage of being easy to manufacture and assemble, reducing costs.

[Brief explanation of the drawing]

The drawings are detailed explanatory diagrams of the invention of this application, in which FIG. 1 is a schematic longitudinal sectional view of one embodiment, FIG. 2 is a longitudinal sectional view of another embodiment, and FIG. 3.4 is a schematic longitudinal sectional view of another embodiment. FIG. 3 is a schematic vertical cross-sectional view of an example. 2...Housing 3...Light source 13...Screen 6...Projection lens 10...Image driving device 9.9', 9' ......LCD panel 12...
...Transmitted light 1.1'1'1'...Liquid crystal image projection device 2 -No.lambda.Using 3...'Jc source 13...Screen 6...Projection lens 12......Transmitted light 1, 1'1' 11...-...Liquid crystal image (ΩAkira equipment

Claims (4)

[Claims] (1) A light source is provided on one side of the housing, a projection lens for the screen is provided on the other side, and a liquid crystal panel connected to an image driving device is interposed between the two to project a liquid crystal image onto the screen. A liquid crystal image projection method, characterized in that the polarization directions of the projection light carrying image information from the projection lens are made equal. (2) The liquid crystal image according to claim 1, wherein the polarization direction is set at a 45° tilt direction between P waves (longitudinal waves) and S waves (transverse waves). Projection method. (3) The above liquid crystal panel does not have a polarizing panel attached to it, and there is one common polarizing panel near the light source of the housing.
A liquid crystal image projection device characterized in that one screen is disposed on the projection lens side. (4) The liquid crystal image projector according to claim 3, wherein the polarizing panel on the projection lens side is attached to the front surface of the screen.