JPH01142785A - Projection type display device - Google Patents

Abstract

PURPOSE: To quickly and independently control the display of a cursor or the like by optically synthesizing or switching displays of a large-capacity display device having a relatively low rewrite speed and a high-speed display device. CONSTITUTION: Light from a laser 7 for rewrite is thrown to a liquid crystal cell 5 through a dichroic mirror 8, and the oriented state of liquid crystal is partially changed to write display data. Meanwhile, a moving picture of a cursor or the like is displayed on a dot matrix liquid crystal display device 6. Light from a light source 1 for projection is thrown to the cell 5 through a dichroic mirror 2, and transmitted light is turned to a dichroic mirror 9 by a reflection mirror 4. Reflected light of the mirror 2 is thrown to the device, and transmitted light is transmitted through the mirror 9. Thus, two displays are synthesized and are displayed on a screen 11 through a lens 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to high-speed display of cursors and the like in large-capacity projection display devices and the like.

BACKGROUND OF THE INVENTION A conventional large-capacity projection display device of this type has a configuration as shown in FIG. 2, for example, as shown in Chapter 10 of Okano and Kobayashi's ``Liquid Crystals and Applied kHz''.

That is, in FIG. 2, a laser beam from a writing laser 7 is irradiated onto a cholesteric liquid crystal cell 5 through a dichroic mirror 8, and the alignment state of the liquid crystal cell 5 is partially changed by the thermal energy of the laser, thereby displaying. The structure is such that data is written, light from a projection light source is irradiated onto the liquid crystal cell 5 in which the data has been written, and the transmitted light is displayed on a screen 11 via a lens 10.

Problems to be Solved by the Invention However, since this type of configuration uses raster scanning or vector scanning using laser thermal writing, it is not suitable for displaying moving images such as a cursor, and the field of application is limited to replacing plotters. There was a problem.

In view of the above problems, the present invention provides a projection type display device capable of displaying a cursor and the like at high speed.

Means for Solving the Problems In order to solve the above problems, the projection display device of the present invention has a configuration in which a large capacity display device with a relatively slow rewriting speed and a high speed display device are optically combined or switched. It is prepared.

Effect of the Invention With the above-described configuration, the present invention can control the display of cursors and the like at high speed and independently, and can expand the field of application.

Embodiment Hereinafter, a projection type display device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a configuration diagram of a projection type display device according to an embodiment of the present invention. In FIG. 1, a laser beam from a writing laser 7 is irradiated onto a cholesteric liquid crystal cell 5 through a dichroic mirror 8, and display data is written by partially changing the alignment state of the liquid crystal cell 5 using the thermal energy of the laser. On the other hand, a moving image such as a cursor is displayed on the dot matrix liquid crystal display device 6. The light from the projection light a11 passes through the dichroic ink mirror 2, and the transmitted light is irradiated onto the cholesteric liquid crystal 5, and the transmitted light is directed to the dichroic ink mirror 9 by the reflecting mirror 4, and the reflected light from the dichroic mirror 2 is displayed on the matrix liquid crystal display. By irradiating the device 6 and transmitting the transmitted light through the dichroic mirror 9, the two displays can be combined and displayed on the screen 11 via the lens 10. FIG. 3 shows an example of a circuit configuration for displaying a cross cursor with high contrast on the dot matrix liquid crystal display device 6 of FIG. 1. A or B depending on the contents of the memory built into the transparent electrode group 23 and 24 configured in a matrix.
Connect the LCD driver 20 and 21 to select the terminal of B
By applying AC voltages of opposite phase to the terminals O and , voltage is applied only to the pixel by the electrode that selects the terminal A, and a nematic liquid crystal and a polarizing plate are combined to display a cursor, etc. in high contrast. be able to. Furthermore, by varying the peak value 0 of the AC voltage applied to the A terminal, it is possible to change the effective value applied to the liquid crystal, thereby controlling the brightness.

In this embodiment, the high-speed display device is a liquid crystal display device, but this is not limited to a liquid crystal display device, and may be a CR7 display device, for example.

Further, although the present embodiment is shown in a single color, it is also possible to use a color by combining the configurations of this embodiment.

Effects of the Invention As described above, the present invention has a configuration in which a large-capacity display device with a relatively slow rewriting speed and a high-speed display device are optically combined or switched to display on a screen, thereby making it possible to display a cursor, etc. The display can be controlled quickly and independently, expanding the field of application.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a projection type display device according to an embodiment of the present invention, FIG. 2 is a block diagram of a conventional projection display device, and FIG. 3 is a block diagram of a dot matrix liquid crystal display device according to an embodiment of the present invention. FIG. 3 is a circuit configuration diagram. 1...Light source for projection, 2,8.9...Dichroic mirror, 3.4...Reflector, 5.
... Cholesteric liquid crystal cell, 6 ... Matrix liquid crystal display device, 7 ... Writing laser, 10 ... Projection lens, 11 ... Screen, 20.21...Liquid crystal driver, 22゜23...Transparent electrode group.

Claims (7)

[Claims] (1) A projection display device that is characterized by optically combining or switching between a large-capacity display device with a relatively slow rewriting speed and a high-speed display device and displaying the result on a screen. (2) The projection type display device according to claim (1), wherein the large capacity display device with a relatively slow rewriting speed is a laser thermal writing liquid crystal display device. (3) The projection type display device according to claim (1), wherein the large capacity display device with a relatively slow rewriting speed is a ferroelectric liquid crystal display device. (4) The projection type display device according to any one of claims (1), (2), and (3), wherein the high-speed display device is a CRT display device. (5) A projection type according to any one of claims (1), (2), or (3), wherein the high-speed display device is a nematic liquid crystal dot matrix display device. Display device. (6) The projection type display device according to claim (5), wherein the high-speed display device is a cross cursor display device. (7) The projection type display device according to claim (6), characterized in that the nematic liquid crystal dot matrix display device is statically driven.