JP2006154870A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of preventing the contrast from decreasing by reducing a light leak from the gap between a case and a liquid crystal panel to a display region. <P>SOLUTION: The liquid crystal display device comprises the liquid crystal panel 1 which displays an image, a back light 2 arranged on the rear side of the liquid crystal panel 1, and the case 3 which has a window 4 for image display formed and which houses the liquid crystal panel 1 and back light 2, and is provided with a light leak preventing material A at an inner peripheral portion inside the case 3 where the window 4 for image display is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device. More specifically, the present invention relates to a transmissive liquid crystal display device used for a display such as a laptop or a personal computer.

  In the conventional liquid crystal display device, for example, as shown in FIG. 5, the light emitted from the backlight 50 is reflected between the case 51 and the liquid crystal panel 52 and then leaks to the liquid crystal display region R. The contrast in the peripheral area was lowered, and the image quality was likely to be unclear. For this reason, as shown in FIG. 5, the distance L from the end portion 52a of the liquid crystal panel 52 to the display region R is widened to reduce the intensity of the reflected light, and the light from the periphery of the image display window 54 of the upper frame 53. This prevents a decrease in contrast at the periphery of the display region R due to leakage of the image.

  However, since the distance L has to be narrowed due to the narrowing of the frame due to the recent miniaturization, there arises a problem that the contrast in the peripheral portion of the display region R is reduced again.

  As a solution to this problem, it is conceivable to attach a light-shielding tape from the upper frame to the liquid crystal panel as described in JP-A-4-241319.

  However, in the technique of sticking a light-shielding tape from the upper frame to the liquid crystal panel, the light-shielding tape may enter the display area and narrow the display area. The light shielding tape is attached to the LCD panel in a case so that the LCD panel is not damaged, and the LCD panel is not overloaded. There is a risk of a decline.

  In view of the above circumstances, an object of the present invention is to provide a liquid crystal display device that can reduce light leakage to a display region and prevent a decrease in contrast because it is between a case and a liquid crystal panel.

  A liquid crystal display device according to the present invention accommodates a liquid crystal panel that displays an image, a backlight disposed on the back side of the liquid crystal panel, and the liquid crystal panel and the backlight on which an image display window is formed. A liquid crystal display device comprising a case, wherein the case has a cushioning property between the case in which the image display window is formed and the liquid crystal panel, and suppresses reflection of light from the backlight. A light leakage prevention material which is a separate member is provided with a gap between the light leakage prevention material and the liquid crystal panel.

  As described above, according to the present invention, conventionally, the light reflected between the inside of the case and the liquid crystal panel and leaking into the display area of the liquid crystal panel can be almost prevented, and the contrast of the display area is improved. Can be made.

  The liquid crystal display device of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a sectional view showing an embodiment of a liquid crystal display device of the present invention, FIG. 2 is a sectional view showing another embodiment of the present invention, and FIG. 3 is a sectional view showing still another embodiment of the present invention. 4 and 4 are cross-sectional views showing still another embodiment of the present invention.

  As shown in FIG. 1, the liquid crystal display device houses and holds a liquid crystal panel 1 for displaying an image, a backlight 2 disposed on the back side of the liquid crystal panel 1, and the liquid crystal panel 1 and the backlight 2. The light leakage prevention material A is provided on the inner wall surface 6 of the upper frame 5 of the case 3 in which the image display window 4 is formed.

  The light leakage preventing material A is not particularly limited as long as it absorbs light and suppresses the reflectance of light. For example, a light reflection preventing film or a light reflection preventing tape can be used. Examples of the light reflection preventing film include black paint sprayed on the inside of the optical dark box and the inside of the lens barrel of the astronomical telescope. Examples of the light reflection preventing tape include a black velvet light absorber used inside the optical dark box and inside the lens barrel of the astronomical telescope.

  The liquid crystal panel 1 includes a glass substrate (TFT substrate) 7 provided with a thin film transistor, a glass substrate (CF substrate) 8 provided with a color filter, and a sealing material for bonding the peripheral portions of both substrates 7 and 8 together. A liquid crystal filled between the substrates 7 and 8 and a polarizing plate provided outside the substrates 7 and 8 can be used.

  In addition, 9 is a circuit board for driving the liquid crystal panel 1, and 10 is a lead wire for connecting the liquid crystal panel 1 and the circuit board 9.

  As the backlight 2, a transparent plate-shaped light guide plate 11 made of a synthetic resin such as acrylic, a fluorescent lamp 12 disposed along the side surface of the light guide plate 11, the fluorescent lamp 12 and the light guide plate 11 are provided. What consists of the reflecting plate 13 arrange | positioned so that it may surround, and the diffusion plate which diffuses the light from the said light-guide plate 11 to the liquid crystal panel 1 side can be used.

  In the present embodiment, out of the light emitted from the backlight, the light that leaks from the terminal part of the liquid crystal panel 1 or between the liquid crystal panel 1 and the backlight 2 and irradiates the inner part of the upper frame 5 is: Since the light reflectance is suppressed to about several percent by the light leakage preventing material, light leakage to the display region R of the liquid crystal panel 1 is reduced. This prevents a decrease in contrast in the peripheral portion of the display region R.

  In the present embodiment, the light leakage prevention material is formed on the entire inner wall surface of the upper frame of the case. However, the present invention is not particularly limited to this, and at least only on the inner wall surface facing the TFT substrate. Can be formed. Alternatively, as shown in FIG. 2, it can be formed on the inner wall surface 6 of the upper frame 5 and the inner wall surface 15 of the side frame 14 of the case 3. By forming on both the inner wall surfaces 6 and 15, light leakage to the display area of the liquid crystal panel can be further reduced as compared with the above embodiment.

  Further, as shown in FIG. 3, the light leakage preventing material A can be formed on the inner wall surface 6 of the upper frame 5, the inner wall surface 15 of the side frame 14, and the inner wall surface 17 of the lower frame 16 of the case 3. In such a case, by using a light reflection preventing film or light reflection preventing tape as the light leakage preventing material A, the light leakage to the display area of the liquid crystal panel is reduced, and the light reflection preventing film or light reflection preventing tape is used. Since the liquid crystal panel and the backlight are wrapped and serve as a cushion, impact resistance and vibration resistance are imparted. In addition, it is preferable to use the light reflection preventing tape whose thickness can be easily managed. For example, in order to make the antireflection tape act as a cushion, the thickness is usually about 0.05 to 0.5 mm, preferably about 0.1 to 0.3 mm.

  In the embodiment shown in FIGS. 1 to 3, the case 3 in which the image display window 4 is formed in the upper frame 5 is shaped to cover the liquid crystal panel 1 and the backlight 2, but in the present invention, For example, as shown in FIG. 4, the case 23 may be shaped such that the lower frame 27 is partially open or only partially covered, as shown in FIG. 4. In the liquid crystal display device, the light leakage prevention material A is provided on the inner peripheral portion of the case 23, for example, the inner wall surface 26 of the upper frame 25, so that light leaks to the display area of the liquid crystal panel as in the above embodiment. Can be prevented.

It is sectional drawing which shows one Embodiment of the liquid crystal display device of this invention. It is sectional drawing which shows other embodiment of this invention. It is sectional drawing which shows other embodiment of this invention. It is sectional drawing which shows other embodiment of this invention. It is sectional drawing which shows an example of the conventional liquid crystal display device.

Explanation of symbols

1 LCD panel
2 Backlight
3 cases
4 Image display window
5 Upper frame 6, 15, 17 Inner wall surface
14 Side frame
16 Lower frame
A Light leakage prevention material

Claims (4)

A liquid crystal display device comprising a liquid crystal panel for displaying an image, a backlight disposed on the back side of the liquid crystal panel, and a case for housing the liquid crystal panel and the backlight, in which an image display window is formed In addition, the liquid crystal panel has a cushioning property between the case in which the image display window is formed and the liquid crystal panel, and prevents reflection of light from the backlight. A liquid crystal display device, characterized in that a material is provided with a gap between the light leakage prevention material and the liquid crystal panel. The liquid crystal display device according to claim 1, wherein the gap penetrates between the inside of the case and the image display window. 3. The liquid crystal display device according to claim 1, wherein the thickness of the light leakage preventing material is 0.05 to 0.5 mm. 4. The liquid crystal display device according to claim 1, wherein the light leakage preventing material is made of a light reflection preventing film or a light reflection preventing tape.

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