JP2009245780A - Panel module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel module of an LED backlight close to a linear light source, thin and with little brightness unevenness, by forming LEDs directly on a glass substrate by the use of semiconductor manufacturing technology. <P>SOLUTION: The panel module with a sidelight system backlight using LEDs 13 as a light source includes thin-film type LEDs 13 directly formed on the glass substrate 11 constituting the panel module with the use of the semiconductor manufacturing process. The LEDs 13 are sealed with resin 48. The LEDs 13 are formed so as to surround a display part on a backside glass surface contrary to a face where TFTs of a TFT substrate constituting the panel module are formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a panel module, and more particularly to a sidelight type backlight of an LCD (liquid crystal display) panel module.

Conventionally, a fluorescent tube has been used as a light source for a backlight of an LCD panel. However, mounting the fluorescent tube requires the fluorescent tube itself and an inverter for driving, and there has been a limit to reducing the thickness of the LCD panel module. Therefore, as a technology for thinning the LCD panel module, a panel module using an LED (light emitting diode) as a light source of a backlight has been put into practical use. For example, Patent Document 1 below discloses a technique for reducing the thickness of a panel by employing a sidelight type LED backlight.
5 and 6 are a configuration diagram and a sectional view of a conventional sidelight type backlight described in Patent Document 1 below. A light source configured by arranging the LEDs 13 on the light source substrate 51 at regular intervals, and a light guide plate 35 disposed beside the light source, the front surface (light emitting surface) 51 of the light guide plate 35 is a light emitting surface, and the back surface 22 and side surfaces are light shielding surfaces. A reflective film 34 is attached to the back surface 22. The light output from the light source 10 passes through the light guide plate 35, enters the LCD panel through the light emitting surface 51 and the diffusion plate 36. According to this structure, the backlight needs to have a thickness corresponding to the height of the minimum light source substrate 51.

In addition, regarding the method of using red, green, and blue (RGB) LEDs in order to obtain white light emission, the drive voltage of the three LEDs differs depending on the light emission color, and the disadvantage that the manufacturing process and manufacturing cost increase. For this reason, there is a drawback that it is difficult to match the characteristics of each color light emitting LED and the color change is large. For this reason, there is also a problem that it is difficult to generate a desired white color. For example, Patent Document 2 below discloses a technique for obtaining a white light source using a blue LED and a phosphor to solve this problem. .
JP-A-6-3527 JP-A-10-97200

  Since the LED is a point light source and the mounting density of the LED chip is limited, there is a problem that uneven brightness tends to occur when used as a backlight as compared with a fluorescent light source that is a line light source. In addition, a certain increase in the thickness of the panel module is inevitable for mounting LED chips.

  Therefore, in order to solve such a problem, the present invention directly forms an LED on a glass substrate by using a semiconductor manufacturing technique, and is a thin panel panel module of an LED backlight close to a linear light source with little luminance unevenness. Is to provide.

In order to solve the above problems, the panel module of the present invention has the following configuration and characteristics.
In a sidelight type backlight using LEDs for an LCD panel, the LEDs are directly formed on a glass substrate using a semiconductor manufacturing process.
The LED is sealed with a resin.
In the backlight, the LED is formed on the back glass surface of the surface of the LCD panel on which the TFT substrate is formed so as to surround the periphery of the display portion.
In the backlight, white light is produced by combining LEDs of RGB three colors.
In the backlight, white light is produced by using a blue LED and a phosphor.

The panel module of the present invention having the above-described configuration can achieve the following effects.
By forming a thin-film LED on the glass substrate of the LCD using a semiconductor manufacturing technology and using it as a backlight, the LED mounting density can be improved, the total volume can be greatly reduced, and the luminance unevenness can be reduced. Thinning of the panel module and the liquid crystal display device can be realized.

The best mode for carrying out the present invention will be described.
FIG. 1 is a structural diagram of a backlight portion of the panel module of the present invention viewed from the back side. The LEDs 13 are arranged in one or more rows on the side of the display unit 12 in the LCD glass substrate 11. Higher brightness can be achieved as the number of LEDs increases. By using the microfabrication technology, the LEDs can be arranged at a higher density than when the LED chips are bonded or the LED substrate is mounted.

  When forming LEDs using semiconductor manufacturing technology, the number of LEDs has little to do with manufacturing cost because the LEDs on the substrate can be formed simultaneously in a single process. Therefore, as shown in FIG. 2, if the LEDs are arranged so as to surround the display unit, higher luminance can be obtained, but the power consumption increases in proportion.

  By adopting the above structure, it is possible to reduce the interval between the mounted LEDs as compared with the conventional LED backlight, and a light source close to a linear light source such as a fluorescent tube can be realized. As a result, luminance unevenness can be reduced. A TFT (thin film transistor) can be formed on the surface (opposite side) of the glass substrate 11.

FIG. 3 is a cross-sectional view taken along line 14 of the backlight portion of the panel module of the present invention shown in FIG. The back side of the backlight in FIG. 1 corresponds to the upper side in FIG. 3, and the near side of the backlight in FIG. 1 corresponds to the lower side in FIG.
An LED 13 is formed on one end of the glass substrate 11. The light emitted from the LED 13 is incident on the light guide plate 35 directly or after being reflected by the reflector 33. The light incident on the light guide plate 35 is guided to the glass substrate 11 of the LCD panel through the diffusion plate 36 and the polarizing plate 37. A reflective film 34 is provided on the back surface of the light guide plate and the side surfaces other than the light incident.

Next, LED formation on a glass substrate will be described.
FIG. 4 is a structural diagram of a blue LED in the backlight portion of the panel module of the present invention. The LED is formed on the glass substrate 11. The process is shown below.
First, a polysilicon layer 41 is formed on a glass substrate, and then this is crystallized. Next, the buffer layer 42 is formed on the silicon layer 41. Next, the n-GaN layer 43 is formed on the buffer layer 42. Next, an active layer (light emitting layer) 44 is formed on the n-GaN layer 43. Next, a p-GaN layer 45 is formed on the active layer 44. Next, contact layers 46 and 47 are formed on the p side and the n side, respectively. Finally, the entire LED is sealed with a resin 48.
In order to obtain white light emission from the LED, the sealing resin 48 includes a phosphor that is excited by absorbing blue light and emits, for example, yellow light or red and green light. Alternatively, the phosphor is not in the resin, but a similar effect can be obtained by providing a fluorescent scattering layer inside the reflector 33 in FIG. 3, and white light can be obtained.

As another method for obtaining white light, there is a method using three kinds of LEDs of red, green and blue. The manufacturing method in this case can be realized, for example, by forming a different compound for each color after the buffer layer in the manufacturing process described above.
By adopting the above structure, the liquid crystal display device can reduce the height required for LED mounting, and the device can be thinned.

It is structural drawing of the backlight part of the panel module of this invention seen from the back surface. It is a structural diagram of the backlight part of the panel module for obtaining high luminance. It is sectional drawing of the backlight part of the panel module of this invention. It is a structural diagram of LED in this invention. It is a structural diagram of a conventional sidelight type backlight. It is sectional drawing of the conventional sidelight system backlight.

Explanation of symbols

11 Glass substrate 13 LED
33 Reflector 34 Reflective film 35 Light guide plate 36 Diffusion plate 37 Polarizing plate 41 Silicon layer 42 Buffer layer 43 n-GaN layer 44 Active layer 45 p-GaN layer 46, 47 Electrode 48 Resin

Claims (5)

In a panel module having a sidelight type backlight using an LED as a light source,
A panel module comprising a thin-film LED directly formed on a glass substrate constituting the panel module using a semiconductor manufacturing process.   The panel module according to claim 1, wherein the LED is sealed with a resin.   The panel module according to claim 1, wherein the LED is formed so as to surround the periphery of the display portion on the back glass surface of the surface of the TFT substrate constituting the panel module on which the TFT is formed.   The panel module according to claim 1, wherein white light is produced by combining LEDs of three colors of RGB.   The panel module according to claim 1, wherein white light is produced by using a blue or ultraviolet LED and a phosphor.

Images