Back light source and front light source and liquid crystal display device

Abstract

A backlight that has small power consumption and can display a high luminance and has a long life with little noise generation, and a liquid crystal display device. This is a backlight 10 that is installed on the back side of an illuminated object 20 and illuminates the illuminated object from the back side and comprises a light guide plate 12, an intermediate light guide body 13A that is arranged along one side end, and a light source 13B that is provided at the end part of the intermediate light guide body. One side of the light guide plate is made a reflecting face 12c that is formed of a concavo-convex shape for reflecting the light propagating inside and the other side of the light guide plate is made an exit face 12b for radiating the light reflected by the reflecting face. And a plurality of grooves 14 that are formed by a low slope part 14a and a steep slope part 14b are formed continuously on the reflecting face in stripe form and the illuminated object is provided at the outside of the exit face.

Description

technical field [0001] The invention relates to a backlight source or a front light source structure suitable for a liquid crystal display device, and a liquid crystal display device with the backlight source or front light source. Background technique [0002] Figure 20 A schematic cross-sectional view showing an example of a conventional transmissive liquid crystal display device. The liquid crystal display device 100 of this example is roughly composed of a liquid crystal display unit 120 and a backlight 110 disposed on the rear side of the liquid crystal display unit 120 . [0003] The structure of the backlight 110 is such that the light emitted by the rod-shaped light source 113 enters the light guide plate 112 from one end surface (incident surface 112a) of the light guide plate 112, and makes it pass through the light guide plate 112 from the side facing the liquid crystal cell 120. (Emitting surface 112b) is emitted. A prism sheet 114 and a white sheet 115 are seq...

AI Technical Summary

Problems solved by technology

[0005] However, when an EL element is used as the light source of such a display machine, in order to obtain several Cd / m 2 About 4~5mW / cm of luminance needs to be consumed 2 There is a problem of high power consumption and low luminance

[0006] In addition, in the EL element, in order to make the element itself emit light, an inverter is required in the amplifier circuit, which will become a noise source for the liquid crystal display device

In the prior art, as noise countermeasures against the inverter, it is necessary to install a noise countermeasure circuit and a shielding device in the liquid crystal display device, which is a major cause of cost increase.

In addition, the above-mentioned inverter also has the disadvantage of high cost as a circuit itself

[0007] In addition, the EL element has the disadvantage of relatively short luminous life, and parts replacement and maintenance are required for long-term use.

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