JPH01209477A - Liquid crystal electrooptic device - Google Patents

Abstract

PURPOSE:To add the function of an overhead projector (OHP) to a personal computer (PC) without any increase in cost by separating a light source part which illuminates an electrooptic panel from other constituent elements. CONSTITUTION:A main body part 31 which includes a liquid crystal panel 11 and a driving circuit 12 and the light source part 32 are used as a PC terminal display while being integrated. This electrooptic device, on the other hand, has the main body part 31 and light source part 32 separated. Namely, cases 15 and 16 are fitted slidably and when the main body part 31 is set on the OHP and put in operation, this is used as an OHP display. Consequently,the PC which has the OHP display function is obtained without any increase in the cost.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid crystal electro-optical device.

[Conventional technology]

Liquid crystal electro-optical devices have been used in a variety of applications ever since they began being used to display numbers in watches and calculators. Near M, super twisted nematic mode (hereinafter referred to as S T
By applying an operation mode with excellent multiplex drive characteristics, such as the N mode (abbreviated as N mode), it is possible to use a display device with 640 x 400 dots or more pixels as a display device for personal computers (hereinafter abbreviated as PC) and word processors. Things with numbers are being commercialized. An electro-optical device used in this manner will be referred to as a PC terminal display hereinafter. In large-capacity display devices such as PC terminal displays, reflective plates are sometimes used to display reflective displays, but in order to improve the appearance, a light source for illumination is installed behind the liquid crystal panel, and transmissive displays are used. Often used.

An example of the structure of such a PCa display is shown in FIG. FIG. 4 shows a cross-sectional view of a transmissive PC terminal display with an illumination light source using an STN mode liquid crystal panel. In FIG. 4, reference numeral 47 denotes a light source, in which a cold cathode tube is used. 48 is a lighting curtain, and 49 is a diffusion plate. Although these elements collectively form the light source section, it can be seen that they are structurally integrated with other parts.

There is also a device that uses a liquid crystal panel, which is basically the same as a PC terminal display, and is installed on an over-the-air projector (hereinafter abbreviated as OHP) to enlarge and project the image displayed on the liquid crystal panel. It has been put into practical use. A projection display device used on such an OHP is hereinafter referred to as an OHP display. In principle, an OHP display is a transmissive type, but since the light source is an OHP, the display device itself does not have a light source.

[Problem to be solved by the invention]

OHP displays are used when a relatively large number of people view the same display, and they are used differently from PC terminal displays, or they are both controlled by a PC and display, so they are completely equivalent system-wise. . Therefore, originally
The same display can be used as an OHP display on a PC
It should also be possible to use it as a terminal display. However, in reality, this is not the case. If the same display could be used for both purposes, OHP display functionality could be added to the PC without increasing costs. The present invention aims to make this possible.

[Means to solve the problem]

The liquid crystal electro-optical device of the present invention includes at least an electro-optic panel using liquid crystal, an electric circuit for driving the electro-optic panel, and a light source for illuminating the electro-optic panel. It is characterized by the fact that the light source part that illuminates the optical panel can be separated from other components.

[Embodiment 1] FIG. 1 shows an embodiment of an electro-optical device according to the present invention. FIG. 1 shows a sectional view of an electro-optical device according to the present invention. FIG. 11 shows a liquid crystal panel. 12 is a driving circuit for the liquid crystal panel.

Reference numeral 13 denotes a circuit board on which wiring for power supply and signals to the drive circuit 12 is formed. 14 is a frame.

15 is a case for the liquid crystal panel and circuit portion. 16 is a case of a light source portion. Reference numeral 17 denotes a lamp as a light source, and here the case is shown in which a cold cathode tube is used. 18 is a lighting curtain, and 19 is a light diffusion plate. A light source portion is formed by a light source lamp 17, a lighting curtain 18, a diffuser plate 19, and a case 16. FIG. 1 shows a state in which a main body portion including a liquid crystal panel and a driving circuit and a light source portion are integrated. In this state, it can be used as a PC terminal display.

However, the electro-optical device of the present invention is as shown in FIGS. 2(a) and 2(b).
), it is possible to separate the main body part and the light source part. That is, the cases 15 and 16 are slidably fitted together. OHP the main body part in Figure 2 (a)
If you set it up and operate it, you can use it as an OHP display.

As described above, in the present invention, by making the light source part separable from other components, it has become possible to use it as both a PC@end display and an OHP display.

The key point of the present invention is that the main body part and the light source part can be integrated or separated. Therefore, the operating principle of the liquid crystal panel used in the present invention may be any.

Furthermore, neither the driving method nor the number of display pixels has any bearing on the content of the present invention.

In this embodiment, a liquid crystal panel operating in the STN mode was used, and the number of zero pixels was 640×400 pixels, and the screen was divided into upper and lower parts and driven at a duty of 1/200. PC
I was able to get a good display on both an i-device display and an OHP display.

[Embodiment 2] Another embodiment of the present invention is shown in FIG. FIG. 3 shows another mechanism for separating and coupling the display main body portion and the light source portion. In FIG. 3, 31 is a main body portion including a liquid crystal panel and a driving circuit. 32 is a light source portion.

When used as a PC terminal display, the main body and the light source portion are integrated using the coupling claw 33. In FIG. 3, the claw 33 is only shown on the left side when facing the display surface.
It is also stored on the right side. When the main body portion and the light source portion are separated and used as an OHP display, the tabs 33 can be removed.

The claw 33 may be made of any elastic material as long as it can press and fix the light source portion 32.

〔Effect of the invention〕

In the present invention, since the main body part and the light source part can be separated, the same display can be used both as a PC terminal display and as an OHP display. This allows OH without increasing costs.
A PC with P display function was realized.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a cross section of an electro-optical device of the present invention. FIGS. 2(a) and 2(b) are cross-sectional views when the electro-optical device of the present invention is separated into a main body portion and a light source portion. FIG. 3 is a diagram showing another embodiment of the present invention. FIG. 4 shows a cross-sectional view of a conventional electro-optical device used in a PC terminal display. 11...Liquid crystal panel 12...Drive circuit 13...Circuit board 14...Frame 15...Case 16...Case 17...Light source lamp 18...Lighting curtain 19... Diffusion plate 31...Body portion 32...Light source portion 33...Coupling claw 41...Liquid crystal panel 42...Drive circuit 43...Circuit board 44...Frame 45...Case 47 ... Light source lamp 48 ... Lighting curtain 49 ... Diffusion plate and above Applicant: Seiko Epson Corporation! / ) ＼ Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a liquid crystal electro-optical device comprising at least an electro-optical panel using liquid crystal, an electric circuit for driving the electro-optic panel, and a light source for illuminating the electro-optical panel, a light source portion for illuminating the electro-optical panel: A liquid crystal electro-optical device characterized by being separable from other components.