JPH02236583A - Liquid crystal display device of projection type - 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 Field of the Invention The present invention relates to a projection type liquid crystal display device that projects an image formed on a liquid crystal panel and displays it on a screen or the like.

2. Description of the Related Art This type of liquid crystal display device is known, for example, from Utility Model Application No. 63-4
The display devices shown in these known examples have a structure as shown in FIG.

In the conventional example shown in FIG. 2, a light source 3 is disposed at the rear of a housing 4, and the light from the light source 3 is diffused by a diffusion lens 2 to illuminate the back surface of the liquid crystal panel 1. As an application of such a liquid crystal display device, a projection type liquid crystal display device has been developed in which the intensity of the light source 30 is increased and the image displayed on the liquid crystal panel 1 is projected onto a screen from a projection lens (not shown) disposed in front. .

Problems to be Solved by the Invention However, the liquid crystal display devices that have been proposed in the past are large in size, and the display element itself is smaller than those using conventional CRTs (cathode ray tubes) for use in general households. However, the devices were not easy to use, and there were many restrictions on where they could be installed. Furthermore, the structure for arranging the projection optical system is complicated, resulting in poor productivity.

The present invention solves the above problems and is easy to use.
It is an object of the present invention to provide a projection type liquid crystal display device with high productivity.

Means for Solving the Problems In order to achieve the above objects, the projection type liquid crystal display device of the present invention includes a projection lens, a liquid crystal panel, a condensing lens, a light source, a reflecting mirror, and a video circuit unit in a cylindrical housing. They have a structure in which they are arranged in sequence in the axial direction.

Function: With the above configuration, each component is arranged in order within the housing, which facilitates positioning and improves productivity in the manufacturing process. In addition, since all the components are housed within the casing, it is easy to use and the external appearance of the device can be made smaller.

EXAMPLE Hereinafter, a projection type liquid crystal display device according to an example of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing the structure of a projection type liquid crystal display device according to an embodiment of the present invention.

In FIG. 1, 18 is a storage case, and inside this cylindrical storage case 18, from the front to the head, there are a projection lens 16, a liquid crystal panel 11, a condensing lens 15, a heat insulating lens 14, and a light source 1.
2, a reflecting mirror 13, a cooling fan 17, a part of the video tuner 11, a power switch 22, and an AC cord 23 are arranged. Each of these members is configured to be able to be stored along the inner surface of the storage case 18, and the heat-insulating lens 14, condensing lens 16, and projection lens 16, which require particularly high positioning accuracy, are housed in the storage case 18, which is divided into two parts in the axial direction. The lenses 14, 15, and 16 are configured so that their peripheral edges are guided and positioned in grooves (not shown) on the inner surface of the storage case 18.

The operation of the projection type liquid crystal display device configured as described above will be described below.

First, before projecting an image onto a screen (not shown), the power switch 22 is turned on, and power is supplied to the video/tuner part 21, the cooling fan 17, and the light source 12 through the AC cord 23.

The output video signal from the video/tuner part 21 to which power is supplied is input to the liquid crystal panel 11, and an image is formed on the effective display surface of the liquid crystal panel 11. On the other hand, the light from the light source 12 is reflected directly or by the reflecting mirror 13 to the front surface l1.
The light passes through the heat-insulating lens 14 and the condensing lens 16, and is focused on the display surface of the liquid crystal panel 11. The heat shielding lens 14 has a function of preventing heat emitted from the light source 12 from being transmitted to the liquid crystal panel 11 and deteriorating the characteristics of the liquid crystal. In addition, a cooling fan 17 is also provided to prevent the characteristics of the liquid crystal from deteriorating.
7 also prevents this heat from propagating to the video/tuner section 21.

The light passing through the liquid crystal panel 11 on which the image has been formed is incident on the projection lens 16, and is projected from the projection lens 16 onto a screen (not shown) to form a projected image.

The cooling fan 17 begins to rotate when the user turns on the power switch 22, but its stop is not simply linked to the turn off of the power switch 22, but rather when a temperature sensor (not shown) is placed in a storage case. By providing the cooling fan 17 in the cooling fan 18 and stopping the cooling fan 17 when the temperature drops below a predetermined temperature, it is possible to effectively prevent the deterioration of the liquid crystal etc. due to heat.

As is clear from the above description, the video/tuner part 22 has the functions of a power supply circuit, a video signal processing circuit, and a tuner circuit. Although the tuning operation knob of the tuner circuit is not shown in the present embodiment, a configuration may be selected in which it is operable to be disposed on the outer surface of the storage case 18 as appropriate.

As described above, according to this embodiment, as a projection type display device using a liquid crystal element, each component can be arranged in a cylindrical residue that is easy to use, and in particular, optical components can be arranged on the inner surface of the housing. , its productivity can be increased.

Effects of the Invention According to the present invention, by arranging optical system members such as a projection lens, a liquid crystal panel, and a video circuit unit in the axial direction within a cylindrical housing, positioning thereof becomes easy and accuracy can be improved in the manufacturing process. This makes it possible to increase productivity and realize a high-quality projection type liquid crystal display device. Furthermore, since all the components can be housed within the cylindrical housing, the usability is improved and miniaturization is also possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a projection type liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a side view of a conventional liquid crystal display device. 11...Liquid crystal panel, 12...Light source,
15...Condensing lens, 16...Projection lens, 17...Cooling fan, 18...
・Storage case, 21... Part of the video tuner,
22...Power switch.

Claims (4)

[Claims] (1) A projection lens, a liquid crystal panel, a condensing lens, a light source, a reflector, and a video circuit unit are arranged in the axial direction in order from the front in a cylindrical housing, and a video signal from the video circuit unit is sent to the liquid crystal panel. 1. A projection type liquid crystal display device, characterized in that it is configured to project and display an image supplied and formed on a liquid crystal panel using light from a light source. (2) The projection type liquid crystal display device according to claim 1, further comprising a cooling fan disposed between the reflecting mirror and the video circuit unit. (3) The projection type liquid crystal display device according to claim 1 or 2, wherein the video circuit unit includes a tuner circuit. (4) A projection type liquid crystal display device characterized in that a power switch for controlling on/off of the video circuit unit is provided so as to be operable from the outside of the cylindrical housing.