JP2000180850A - Construction of backlight liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize, to make light in weight and to make inexpensive a liquid crystal display element formed by superposing a front transparent substrate and a rear transparent substrate and by enclosing a liquid crystal in between by arranging a light source such as a light emitting diode on the rear side. SOLUTION: On a front transparent substrate 2 out of both transparent substrates 2, 3 in the liquid crystal display element 1, a swelled out part 4 from the side face of the rear transparent substrate 3 is integrally provided. By mounting a light emitting diode 5 as a light source on the rear side of the swelled out part 4 so as to make a light beam from the light emitting diode go toward the inside of the rear transparent substrate 3, the rear transparent substrate 3 is made to be a backlight light source which as a whole shines as a plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight type liquid crystal display device in which a light source is provided on the back of a liquid crystal display element, and to the structure thereof.

[0002]

2. Description of the Related Art As is well known, a backlight type liquid crystal display device using a light source such as a light emitting diode is made of a transparent body having a reflective plate adhered to the back side of a liquid crystal display element. Providing a light guide plate and providing at least one light source such as a light emitting diode on at least one side surface of each side surface around the light guide plate so that light from the light source goes toward the inside of the light guide plate. Accordingly, the light guide plate is configured to be a backlight light source that illuminates the surface of the light guide plate in a planar shape.

[0003]

However, in this conventional backlight type liquid crystal display device, a light guide plate provided with a light source such as a light emitting diode is disposed on the back side of the liquid crystal display element. In addition to the overall thickness being increased by the provision of the light guide plate on the back surface side of the liquid crystal display element, in addition to the fact that both the liquid crystal display element and the light source such as the light emitting diode in the light guide plate provide an electrical connection to the outside. It requires a complicated connection means, so that the entire liquid crystal display device is considerably increased in size and weight, and the price is considerably increased due to the large number of parts and the number of electrical connection points. There was a problem.

An object of the present invention is to provide a structure of a backlight type liquid crystal display device which solves these problems.

[0005]

In order to achieve this technical object, the present invention provides a liquid crystal display device comprising two transparent substrates which are overlapped so as to enclose a liquid crystal therebetween. Of the two transparent substrates in the front transparent substrate on the display surface side, the two transparent substrates are integrally provided with an outwardly protruding portion from the side surface of the rear transparent substrate on the side opposite to the display surface of the two transparent substrates. A light source such as a light-emitting diode is mounted on the rear surface of the protruding portion so that light from the light source goes to the inside of the rear transparent substrate, and connection electrode terminals for the liquid crystal display element and the light source are provided. " It was configured.

[0006]

In this configuration, light emitted from a light source such as a light emitting diode into the inside of the rear transparent substrate of the liquid crystal display element alternates between the front surface and the back surface of the rear transparent substrate. Since the entire rear transparent substrate shines in a plane like the conventional light guide plate, the rear transparent substrate itself in the liquid crystal display element is a backlight light source. It works.

Further, in addition to mounting the light source such as the light emitting diode on a portion of the liquid crystal display element that protrudes from the front transparent substrate, a connection electrode terminal for the light source and a connection electrode terminal for the liquid crystal display element are provided. Is provided, the electrical connection of the liquid crystal display element and the light source to the outside can be extremely simplified by the electrical connection to the protruding portion.

Therefore, according to the present invention, the thickness of the backlight type liquid crystal display device can be reduced, the electrical connection structure with the outside can be simplified, and the number of parts can be reduced. Has the effect of achieving cost reduction. In particular, as described in claim 2, by forming the back surface of the rear transparent substrate of the two transparent substrates in the liquid crystal display element on a fine uneven surface such as a textured dot surface, all of the light in the rear transparent substrate is formed. Can be uniformly reflected on the surface side by the fine uneven surface such as the textured dot surface, so that the light utilization rate can be improved,
There is an advantage that unevenness of backlight light can be reduced.

Further, as described in claim 3, each of the two transparent substrates in the liquid crystal display element has a side surface of the rear transparent substrate, except for a portion of the side surface corresponding to the light source such as the light emitting diode. By forming the light-shielding reflective film, light entering the rear transparent substrate can be confined in the rear transparent substrate, so that the light utilization rate can be further improved.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. In this figure, reference numeral 1 indicates a liquid crystal display element, and this liquid crystal display element 1
The front transparent substrate 2 on the front side and the rear transparent substrate 3 on the rear side are overlapped so as to seal liquid crystal therebetween. The rear surface 3a of the rear transparent substrate 3 in the liquid crystal display element 1 A protruding portion 4 is formed integrally on the front transparent substrate 2 of the liquid crystal display element 1 and protrudes outward from the side surface of the rear transparent substrate 3. A driving IC chip 5 for the liquid crystal display element 1 is mounted on the back surface of the protruding portion 4.

A plurality of light emitting diodes 6, which are one example of a light source, are provided on the back surface of the protruding portion 4 of the front transparent substrate 2 so that light from each of the light emitting diodes 6 is applied to the rear of the liquid crystal display element 1. The liquid crystal display device 1 is mounted so as to face the inside of the transparent substrate 3.
The connection electrode terminals 8 are provided side by side, and a cable to the outside, for example, a flat flexible cable 9 or the like is connected to each of the connection electrode terminals 7 and 8.

On the other hand, of the two transparent substrates 2 and 3 of the liquid crystal display element 1, light-shielding reflective portions are provided on the respective side surfaces around the rear transparent substrate 3 except for portions corresponding to the respective light emitting diodes 5 on the side surfaces. The film 10 is formed. In the liquid crystal display element 1, a light-transmitting polarizing plate 11 is adhered to the front surface of the front transparent substrate 2, and a light-shielding reflecting plate 12 is adhered to the rear surface of the rear transparent substrate 3.

Although not shown, on the back surface of the protruding portion 4 of the front transparent substrate 2, between each transparent electrode on both transparent substrates 2 and 3 and the IC chip 5,
A wiring pattern for electrically connecting each of the IC chip 5 and the connection electrode terminal 7 and between each of the light emitting diodes 6 and the connection electrode terminal 8 is formed.

Further, each of the light emitting diodes 5 may be sealed with a transparent synthetic resin 13. In this configuration, each light emitting diode 5 is connected to the liquid crystal display element 1.
The light emitted into the rear transparent substrate 3 in the above-mentioned state travels inside the rear transparent substrate 3 while being alternately refracted between the front surface and the back surface, so that the entire rear transparent substrate 3 is planar. Therefore, it functions as a backlight light source.

In this case, since the rear surface 3a of the rear transparent substrate 3 in the liquid crystal display element 1 is formed on a fine uneven surface such as a textured dot surface, all the light in the rear transparent substrate 3 is transmitted. Since the light can be uniformly reflected on the surface side by the fine uneven surface such as the textured dot surface, the light utilization rate can be improved and the unevenness of the backlight light can be reduced.

In each of the two transparent substrates 2 and 3 in the liquid crystal display element 1, each side surface around the rear transparent substrate 3 serving as a backlight light source has a portion corresponding to each light emitting diode 5 in the side surface. With the exception that the light-shielding reflective film 10 is formed, light entering the rear transparent substrate 3 can be confined in the rear transparent substrate 3.

The present invention is not limited to the use of the light emitting diode as the light source of the backlight as described above, but a cylindrical or spherical light source whose diameter is substantially equal to or smaller than the thickness of the rear transparent substrate 3. Lights can be used.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a perspective view when the liquid crystal display device according to the embodiment of the present invention is viewed from the front side.

FIG. 3 is an enlarged perspective view of the liquid crystal display device according to the embodiment of the present invention when viewed from the back surface side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liquid crystal display element 2 Front transparent substrate 3 Rear transparent substrate 4 Protruding part 5 Driving IC chip 6 Light emitting diode as a light source 7, 8 Connection electrode terminal 9 Flat flexible cable

Claims (3)

[Claims] 1. A liquid crystal display device comprising two transparent substrates stacked so as to enclose a liquid crystal therebetween, wherein a front transparent substrate on a display surface side of the two transparent substrates in the liquid crystal display device is provided with: Of the two transparent substrates, a protruding portion extending outward from the side surface of the rear transparent substrate opposite to the display surface is integrally provided, and a light source such as a light emitting diode is provided on the back surface of the protruding portion. Along with mounting the light toward the inside of the rear transparent substrate,
A structure of a backlight type liquid crystal display device, wherein connection terminals for the liquid crystal display element and the light source are provided. 2. The liquid crystal display device according to claim 1, wherein the rear surface of the rear transparent substrate of the two transparent substrates in the liquid crystal display element is
A structure of a backlight type liquid crystal display device characterized by being formed on a fine uneven surface such as a textured dot surface. 3. The light-shielding device according to claim 1, wherein each of the two transparent substrates in the liquid crystal display element has a light-shielding property on each side surface of the rear transparent substrate, except for a portion of the side surface corresponding to the light source such as the light emitting diode. The structure of a backlight type liquid crystal display device, characterized by forming a reflective film.