JPH0318886A - Projection type liquid crystal display device - Google Patents

Abstract

PURPOSE:To easily obtain a large screen, and also, to use the subject device as a liquid crystal television at the time of moving while carrying it by disposing a reflection type projection optical system and a transmission type optical system against one piece of liquid crystal display panel. CONSTITUTION:A light beam generated from a light source 1 passes through a liquid crystal display panel 2 and a polarizing plate 3, is reflected by the reflecting mirror 4 of a Fresnel type, and thereafter, passes through the polarizing plate 3 and the liquid crystal display panel 2 again, passes through a polarizing plate 7 positioned in a projection head part 13, is condensed to a projection lens 5, and reflects an image on a screen 12 from a reflecting mirror 6 for projection. The projection head part 13 and a head supporting part 14 can be folded against a body base part 15, and by interlocking with the folding operation of the head supporting part 14, the liquid crystal display panel 2 moves, and the surface and the reverse side are pinched with a polarizing plate 8 and a diffusing plate 9. Also, on the lower part of the diffusing plate 9, a light source 10 and a reflecting mirror 11 are provided. In such a manner, the subject device is miniaturized and reduced in weight, and a large screen can be obtained, and also, at the time of moving while carrying it, it can be used as a compact liquid crystal television.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a small, lightweight, and highly portable liquid crystal display device, and a projection type liquid crystal display that enables normal liquid crystal display and large screen projection image display. It is related to the device.

[Background Art] In recent years, with the development of video culture and the spread of image information to the general public, it is expected that display devices, which are image display devices, will become increasingly diverse. The display device is a CRT (cathode ray tube) display device, liquid crystal, or EL.
(ELECTROLUMINESCENCE) and the like can be mentioned. On the other hand, the spread of media that provides image information has been remarkable, such as Lasertisf, 1
/2-ear fVTR, 8mm VTR, video floppy IC cards, etc. have become readily available as media. At the same time, if you want to enjoy the video personally,
The above-mentioned display devices are easy to carry and can be enjoyed in places where there is no TV, or while on a moving train or bus, or if you want to have an impressive large screen like a theater at home. A variety of televisions have been made using it.

For example, there are liquid crystal televisions and small cathode ray tube televisions for personal and portable use, and large cathode ray tube televisions and projection type televisions for large screens.

In particular, as shown in Japanese Patent Application Laid-Open No. 63-9396,
Image display devices and the like have been proposed that combine screens and have an easily portable structure.

[Problems and Objects to be Solved by the Invention] However, the cathode ray tube type has a limited screen size and is limited to stationary use due to the large size and weight of the housing.

In addition, since the projection type uses a halogen lamp or xenon lamp as a light source to project the image onto the screen, it requires a considerable amount of power to be supplied from a household 100 volt power supply, so it cannot be used when traveling. I'm not going. The present invention solves these problems by combining a reflective projection optical system and a transmissive optical system (backlight optical system) with one liquid crystal display panel, which is small and lightweight. To provide a projection type liquid crystal display device which is highly portable and can easily provide a large screen, but can also be used as a small liquid crystal television when carried on the go and requires low power consumption. be.

[Means for Solving the Problems] A projection type liquid crystal display device of the present invention includes a light source for projection, a liquid crystal display panel for displaying an image, and a polarizing plate, and reflects light that has passed through the liquid crystal display panel. In a projection type liquid crystal display device comprising a Fresnel reflector for condensing light and a projection optical system for enlarging and projecting the light including image information reflected by the Fresnel reflector, the reflective condenser includes the Fresnel reflector. A transmissive optical system is provided adjacent to the optical system and includes a light source diffuser plate and a polarizing plate that are separate from the light source, and the liquid crystal display panel moves between the reflective condensing optical system and the transmissive optical system. The present invention is characterized in that the liquid crystal display panel moving mechanism is interlocked with a folding and moving mechanism of a projection head section comprising the projection light source and the projection optical system.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a cross-sectional view showing the structure of the main parts of a projection type liquid crystal display device in an embodiment of the present invention, and shows when it is used as a projection device.

First, the structure and operation of the projection device will be explained along the optical path. Light generated from a light source 1 using a halogen lamp or the like passes through a liquid crystal display panel 2 and a polarizing plate 3, is reflected by a Fresnel type reflector 4, passes through the polarizing plate 3 and the liquid crystal display panel 2 again, and is projected. The light passes through the polarizing plate 7 located in the head section 13 and is focused on the projection lens 5. The light focused by the lens 5 changes its optical path by the projection mirror 6 and projects an image on the screen 12.

The projection head section 13 has a mechanism that is fixed to the main body base section 15 via the head support section 14 . The projection head part 13 and the head support part 14 and the joint parts of the head support part 14 and the main body base part 15 each have rotation, sliding, and fixing mechanisms, and the projection head part 13 and the head support part 14 have It has a structure that can be folded against the main body base part 15.

Next, a detailed explanation of each part will be added. The light source 1 uses a halogen or metal halide lamp of 1°O volt and 150 to 300 watts to illuminate the liquid crystal panel 2 uniformly.

The liquid crystal display panel 2 includes a thin film transistor (TPT).
Alternatively, a liquid crystal color display panel using MIM or the like was used. The polarizing plate 3 is attached to the panel 2 with colorless transparent glue or the like. The reflecting mirror 4 is made by depositing aluminum or the like on a designed Fresnel lens to distribute the light emitted from the light source 1 onto the projection lens 5-. The polarizing plate 7 is the same as the polarizing plate 3, but the polarizing plate 7 is placed with a phase shift of 90' from each other. The projection lens consists of a lens system of three or more lenses in three groups, and has a function of focusing the image 12 projected on the screen.

FIG. 2 is a main cross-sectional view showing a state in which the projection radar portion 13 and the head support portion 14 are housed using the above-mentioned folding mechanism. In conjunction with the operation required to fold the head support section 14, the liquid crystal display panel 2 is moved to the main body base section 15.
It is moved by a slide mechanism installed in the. After the liquid crystal display panel 2 has been moved, the front and back sides of the panel are sandwiched between the polarizing plate 8 and the diffusing plate 9.

A light source 10 and a reflecting mirror 11 are provided below the diffuser plate 9 as a backlight light source system. That is, when the projection head section 13 and the head support section 14 are housed and the device is made compact, the screen of the liquid crystal display panel can be viewed directly as a normal small liquid crystal television using the aforementioned backlight optical system. .

In the embodiment of the present invention, 5 is used as the liquid crystal display panel 2.
Although we used a panel of 3 to 10 inches in size, any panel that can be uniformly irradiated with light from the light source and has an appropriate size for direct viewing using the backlight optical system can be used. This is also possible depending on the size.

In this example, the reflective projection optical system and the transmissive optical system are fixed, and the liquid crystal display panel is moved between them, but the same applies even if the liquid crystal display panel is fixed and the optical system is moved. You can get the following functions.

[Effects of the Invention] As described above, according to the present invention, the reflective projection optical system and the transmissive optical system are installed on the two liquid crystal display panels as in the above-mentioned embodiments, thereby making the display panel compact and lightweight. To provide a projection type liquid crystal display device which is excellent in portability and can easily obtain a large screen, and which can be used as a liquid crystal television when traveling with a small amount of electric power.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a schematic structure of a projection type liquid crystal display device according to an embodiment of the present invention when used as a projection device. FIG. 2 is a sectional view showing a schematic structure of a projection type liquid crystal display device according to an embodiment of the present invention when the projection mechanism is housed. 1..Light source 2..Liquid crystal display panel 3..Polarizing plate 4..Reflecting mirror 5..Projection lens 6..Reflecting mirror 7.8..Polarizing plate 9..Diffusion plate 10..Light source
11.Reflector 12.Screen 13.
- Projection head section 14... Head support section 15... Main body base section or higher

Claims (1)

[Claims] A light source for projection, a liquid crystal display panel for displaying an image, and a polarizing plate, reflecting the light passing through the liquid crystal display panel;
In a projection type liquid crystal display device comprising a Fresnel reflector for condensing light and a projection optical system for enlarging and projecting the light including image information reflected by the Fresnel reflector, the reflection condenser includes the Fresnel reflector. Adjacent to the optical system, it has a transmission type optical system consisting of a light source different from the light source, a diffuser plate, and a polarizing plate,
The liquid crystal display panel has a mechanism for moving the liquid crystal display panel between the reflective condensing optical system and the transmissive optical system, and the liquid crystal display panel moving mechanism folds and moves a projection head section comprising the projection light source and the projection optical system. A projection type liquid crystal display device characterized by interlocking with a mechanism.