JPS626292A - Liquid crystal display unit - 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 liquid crystal display device comprising an optical shutter, a color filter, and a light source made of liquid crystal.

Conventional technology In recent years, liquid crystal display devices (hereinafter referred to as LCDs), which use liquid crystals as optical shutters, color filters with selective transmission characteristics in the visible range, and light sources, have become a means of transmitting various types of information in bright indoor environments. It is becoming popular as one.

The configuration of the device is as shown in FIG.
It consists of a liquid crystal 7 and a light source 8 which are integrated with each other, and the information displayed is perceived as light 9. It is essential that the light source 8 has high brightness and can evenly illuminate the entire surface of the liquid crystal panel. Fluorescent lamps are used in most applications to meet this requirement.

As fluorescent lamps, straight tube type fluorescent lamps with a tube diameter of 26 to 38 m have been put into practical use, taking into account screen brightness, screen size, ease of handling, etc. Installation of these fluorescent lamps is carried out in the 8th
As shown in FIG. 9 and FIG. 9, it is common to arrange them as closely as possible in the vertical or horizontal direction depending on the screen size. The spacing between the lamps is determined based on the uniformity of screen brightness and ease of maintenance, but they are generally installed at intervals of 10 to 15 rJf.

Problems to be Solved by the Invention One of the major problems when using a fluorescent lamp as a light source for an LCD is that it is difficult to use a fluorescent lamp as a light source. When the lamps are lit in a straight line on home plate, the brightness of the screen decreases due to the end of the lamp caps being adjacent to each other, resulting in uneven brightness of the screen.

That is, if at least one of the vertical and horizontal sides of the screen is longer than 240 cm of the longest 110 watt type of existing fluorescent lamps, it is necessary to light at least two lamps in a straight line. In this case, the brightness of the part of the screen corresponding to the part where the caps of the two lamps are adjacent to each other decreases because the amount of light reaching the part is smaller than that of other parts, and as a result, the uniformity of the screen brightness decreases. There was a problem in that the value decreased.

In order to solve this problem, as shown in FIGS. 10 and 11, a fluorescent lamp 11 for auxiliary illumination is added to the adjacent portion of the caps 10 in a direction perpendicular to the line connecting the caps. By attaching the light and lighting it, a structure is adopted that suppresses a decrease in the brightness of the adjacent part of the white gold. However, the L
In a CD, mounting the fluorescent lamp 11 for auxiliary illumination complicates the structure, makes maintenance extremely difficult, and furthermore, the total number of lamps increases, which increases power consumption. The present invention provides an LCD that has no uneven brightness on the screen, has a simple structure, and is easy to maintain.

Means for Solving the Problems In the present invention, the LCD screen consists of two or more units,
Each unit is equipped with an optical shutter made of liquid crystal, a color filter, and a light source, and a flat fluorescent lamp is used as the light source.

With this configuration, the liquid crystal surface of each unit is illuminated uniformly, so the reduction in brightness between units is suppressed, and the entire screen has a uniform brightness level, which improves brightness uniformity. The quality will be excellent.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 2, the LCD 1 consists of a total of 30 units 2. As shown in FIG. 1, each unit 2 has a liquid crystal display 3. Color filters 4 are mounted one on top of the other, and a flat fluorescent lamp 6 is mounted on the back side.

The size of unit 2 is limited by the dimensions of the flat fluorescent lamp, but considering ease of handling, lamp efficiency, etc.
The length of the short side of the unit is preferably at least 6c01. In this example, the rectangle has a short side of 18 cm and a long side of 25 cm. The tube diameter of the flat fluorescent lamp 6 is closely related to the screen brightness; the thinner the tube, the higher the brightness.On the other hand, if the tube length is the same, the thinner the tube diameter, the higher the starting voltage, so the difference between the two It is important to consider balance when determining the pipe diameter. In this example, one with an outer diameter of 28 ff was used. The flat fluorescent lamp 5 has U as shown in FIG.
A combination of alternating letter-shaped valves connected in series within a plane was used. Other examples include one in which U-shaped valves are connected in series as in the previous embodiment, as shown in FIG.
As shown in the figure, it is possible to use a material in which H-type pulps are connected in series as in the above embodiment. Among these, the one in Figure 4 is intended to improve the brightness in the corner of the unit, and the one in Figure 5 is due to the rise in tube wall temperature when a large number of fluorescent lamps are used as in the present invention. The coldest part at the end is effectively used to prevent a decrease in efficiency.

The lamp length (width) is determined by the unit size and tube diameter.
In this example, the lamp length is 160 mm.

This is the same length as the existing 6.6 watt lamp. An LCD 1 was manufactured using a unit in which such a lamp was attached as shown in FIG. 6, and the screen brightness distribution was measured. The measurement points are shown in the figure. Measurement point A in Fig. 6,
B, C and A/, f3/, C/ are all points on the boundary line between unit 2 and unit 2, and among them, measurement points A/, B/, and C' are the corners of unit 2. This is partly the above point. For comparison, measurement points on a conventional LCD are shown in FIG. Among the measurement points in FIG. 9, measurement point E is a point where two caps are adjacent to each other,
Same thing.

F is the central part of the lamp. In addition, in FIG. 11, the measurement point E' is determined by adding three fluorescent lamps 11 for auxiliary illumination to the device shown in FIG. 8 as shown in FIG. The LCD of this embodiment, which is the center fluorescent lamp 110 portion located at
The measurement results of various types of conventional LCDs are shown in FIG. , the screen brightness distribution became uniform, and no brightness unevenness was observed on the screen. On the other hand, with the conventional type, the uneven brightness was finally resolved only after three fluorescent lamps were installed for auxiliary illumination.

In addition, the LCD according to the embodiment of the present invention can eliminate uneven brightness on the screen without additionally lighting a fluorescent lamp for auxiliary illumination. It also consumes less power. Moreover, this LCD has a structure in which the screen is divided into a plurality of units 2, and each unit 2 is equipped with a liquid crystal 3, a color filter 4, and a flat fluorescent lamp 6, so in combination with the above, maintenance is extremely easy. becomes.

Note that the flat fluorescent lamp may be of a reflective type or an aperture type, if necessary.

As described in detail, the present invention comprises two or more screens,
By installing a liquid crystal optical shutter, a color filter, and a flat fluorescent lamp in each unit, there is virtually no uneven brightness on the screen, and the structure is simple and maintenance is extremely easy. Accordingly, it is possible to provide a liquid crystal display device having effects.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway enlarged perspective view of a unit of a liquid crystal display device according to an embodiment of the present invention, FIG. 2 is a perspective view of the same liquid crystal display device, and FIG. 3 is an example of a flat fluorescent lamp. Front view,
4 and 6 are front views respectively showing other examples of flat fluorescent lamps, and FIG. 6 is a partially cutaway front view showing an example of the arrangement of flat fluorescent lamps in the same liquid crystal display device. Fig. 7 is a diagram showing the brightness distribution of a string liquid crystal display device, Fig. 8 is a partially cutaway perspective view showing a conventional liquid crystal display device, Fig. 9 is a partially cutaway front view of the same, and Fig. 10 is a diagram showing a conventional liquid crystal display device. FIG. 11 is a partially cutaway perspective view showing the liquid crystal display device of the example, and FIG. 11 is a partially cutaway front view of the same. 1...LCD, 2...Unit, 3...
...Liquid crystal, 4...Color filter, 6...
...Flat fluorescent lamp 0@1 Fig. 2--1 Nitsu L Isamu 2 Fig. 3 Fig. 7 Fig. 4 Spray - Yono 1 skin placement. (0 to

Claims (1)

[Claims] 1. A liquid crystal display device characterized in that the screen is composed of two or more units, each unit is equipped with an optical shutter made of liquid crystal, a color filter, and a light source, and the light source is composed of a flat fluorescent lamp.