JP2012242765A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To thin a liquid crystal display device without affecting an optical sheet.SOLUTION: The liquid crystal display device includes: a liquid crystal display panel 10; a backlight 16 opposed to the liquid crystal display panel 10; a frame 22 for supporting an end of the liquid crystal display panel 10 by arranging the backlight 16 inside; and an adhesive sheet 28 adhered to the end of the liquid crystal display panel 10 and the frame 22. The backlight 16 includes the optical sheet 20 on a side closest to the liquid crystal display panel 10. The adhesive sheet 28 includes a projection 36 projecting between the liquid crystal display panel 10 and the optical sheet 20. The projection 36 of the adhesive sheet 28 includes a non-adhesive section 38 which is a surface on the optical sheet 20 side and does not exhibit adhesiveness at least at the leading end.

Description

  The present invention relates to a liquid crystal display device.

  In a liquid crystal display device having a backlight, the liquid crystal display panel is attached to a receiving portion of a resin frame with an adhesive tape (see Patent Document 1). Since the resin frame is a molded product, its molding dimension requires a thickness capable of resin flow, and the current resin material requires a thickness of 0.18 mm or more. In the structure in which a part of the resin frame is overlapped on the edge of the backlight and this part is used as the receiving part of the liquid crystal display panel, it is necessary to add 0.18mm which is the thickness of the resin frame and the thickness of the adhesive tape. There was a limit to thinning the device.

JP 2009-217116 A

  If the backlight is arranged inside the resin frame, the receiving portion of the liquid crystal display panel and the backlight do not overlap with each other, so that the apparatus can be thinned.

  However, in that case, since the optical sheet placed on the light guide plate and the receiving part of the liquid crystal display panel are arranged next to each other, the adhesive tape attached to the receiving part adheres to the optical sheet, and the optical sheet is swelled. There was a problem that.

  An object of the present invention is to reduce the thickness without affecting the optical sheet.

  (1) A liquid crystal display device according to the present invention includes a liquid crystal display panel, a backlight opposed to the liquid crystal display panel, a frame that supports the end of the liquid crystal display panel by disposing the backlight inside, An adhesive sheet that adheres to the end portion of the liquid crystal display panel and the frame, and the backlight includes an optical sheet closest to the liquid crystal display panel, and the adhesive sheet includes the liquid crystal display panel. A protrusion protruding between the optical sheet and the optical sheet, wherein the protrusion of the adhesive sheet includes a non-adhesive part that is a surface on the optical sheet side and that does not exhibit adhesiveness at least at the tip. Features. According to the present invention, since the non-adhesive part in the protruding part of the adhesive sheet does not adhere to the optical sheet, the influence of the adhesive sheet on the optical sheet can be avoided.

  (2) In the liquid crystal display device described in (1), the entire protruding portion may be the non-adhesive portion.

  (3) In the liquid crystal display device described in (1), the entire area of the adhesive sheet facing the optical sheet may be the non-adhesive portion.

  (4) In the liquid crystal display device described in any one of (1) to (3), the pressure-sensitive adhesive sheet includes a base material and a first pressure-sensitive adhesive attached to the liquid crystal display panel side of the base material. A layer and a second adhesive layer attached to the frame side of the base material may be included.

  (5) In the liquid crystal display device described in (4), the non-adhesive portion may be a layer that covers the second adhesive layer.

  (6) In the liquid crystal display device described in (5), the non-adhesive portion may be made of ink.

  (7) In the liquid crystal display device described in (4), the second adhesive layer is provided to avoid a region of the base material facing the optical sheet, and the second adhesive layer of the base material is avoided. The area | region which is may be the said non-adhesive part.

  (8) In the liquid crystal display device according to (4), the second adhesive layer is provided in a region facing the frame of the base material, and the region of the base material facing the optical sheet has the As the non-adhesive part, a layer formed by curing the second adhesive layer may be provided.

It is sectional drawing which shows the liquid crystal display device which concerns on embodiment of this invention. It is an enlarged view of the adhesive sheet shown in FIG. It is a figure which shows the adhesive sheet which concerns on the modification 1. It is a figure which shows the adhesive sheet which concerns on the modification 2.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a liquid crystal display device according to an embodiment of the present invention.

  The liquid crystal display device includes a liquid crystal display panel 10. The liquid crystal display panel 10 has a pair of substrates 12 (glass substrates), and a liquid crystal (not shown) is interposed therebetween. One substrate 12 is a TFT (Thin Film Transistor) substrate or array substrate including thin film transistors, pixel electrodes, wirings, and the like, and the other substrate 12 is a color filter substrate. The driving method of the liquid crystal display panel 10 may be any method such as an IPS (In Plane Switching) method, a TN (Twisted Nematic) method, or a VA (Vertical Alignment) method, and electrodes and wirings corresponding to the method are formed. The

  The liquid crystal display panel 10 includes a polarizing plate 14. Polarizers 14 are attached to both surfaces of the pair of substrates 12 respectively. The polarizing plate 14 is attached to a region (region surrounded by the peripheral end portion of the substrate 12) that avoids the end portion (circumferential end portion) of the substrate 12.

  The liquid crystal display device has a backlight 16. The backlight 16 faces the liquid crystal display panel 10. The backlight 16 includes a light guide plate 18 for converting light of a light emitting diode (not shown) as a point light source into a surface light source and irradiating the liquid crystal display panel 10. The light emitting surface of the light guide plate 18 is directed toward the polarizing plate 14.

  The backlight 16 includes an optical sheet 20 on the side closest to the liquid crystal display panel 10. That is, the optical sheet 20 is disposed between the liquid crystal display panel 10 and the light guide plate 18. The optical sheet 20 includes a diffusion sheet and a prism sheet. The optical sheet 20 is smaller than the polarizing plate 14. Specifically, the optical sheet 20 has a surface facing the light emitting surface of the backlight 16 and a surface opposite to this surface, and the outer shape of these surfaces is smaller than the outer shape of the polarizing plate 14. Here, the small outer shape means not only a small area but also a shape in which the smaller outer shape completely fits inside the larger outer shape.

  The liquid crystal display device has a frame 22. The frame 22 is a resin molded product and is also called a mold. A backlight 16 is disposed inside the frame 22. Specifically, a through hole is formed in the frame 22, and the backlight 16 is disposed in the through hole. A reflection sheet 24 is disposed below the backlight 16 (on the side opposite to the liquid crystal display panel 10) so that light from the light guide plate 18 does not leak downward. The reflection sheet 24 is disposed from the bottom of the backlight 16 to the bottom of the frame 22.

  The frame 22 supports the end of the liquid crystal display panel 10. For example, the end of the polarizing plate 14 attached to the lower substrate 12 of the liquid crystal display panel 10 is supported by the frame 22. The frame 22 has a wall portion 26 that rises around the liquid crystal display panel 10, and the wall portion 26 surrounds and protects the liquid crystal display panel 10.

  FIG. 2 is an enlarged view of the adhesive sheet 28 shown in FIG. An adhesive sheet 28 is interposed between the end of the liquid crystal display panel 10 (for example, the polarizing plate 14) and the frame 22. The pressure-sensitive adhesive sheet 28 includes a base material 30 and a first pressure-sensitive adhesive layer 32 and a second pressure-sensitive adhesive layer 34 that are respectively attached to both surfaces of the base material 30. The first adhesive layer 32 of the adhesive sheet 28 adheres to the end of the liquid crystal display panel 10 (for example, the polarizing plate 14). The second adhesive layer 34 is adhered to the frame 22.

  The adhesive sheet 28 has a light shielding property. If the base material 30 has light-shielding properties, the first adhesive layer 32 and the second adhesive layer 34 may be formed from a light-transmitting material. The adhesive sheet 28 has a shape surrounding a display area where an image of the liquid crystal display panel 10 is displayed, and is arranged so as not to overlap the display area. Further, the pressure-sensitive adhesive sheet 28 has a size (outer shape) exceeding the peripheral edge outside the display area of the liquid crystal display panel 10. The adhesive sheet 28 covers the peripheral edge of the liquid crystal display panel 10 on the lower side. Therefore, the light from the backlight 16 travels in the direction of the display area, but is blocked by the light-shielding pressure-sensitive adhesive sheet 28 so that it does not enter the peripheral portion of the liquid crystal display panel 10. This prevents light from leaking to the outside of the liquid crystal display panel 10.

  The pressure-sensitive adhesive sheet 28 has a protruding portion 36 that protrudes between the liquid crystal display panel 10 and the optical sheet 20. That is, the adhesive sheet 28 includes a portion located between the liquid crystal display panel 10 and the frame 22 and a protrusion 36 that overlaps the liquid crystal display panel 10 but does not overlap the frame 22.

  The protruding portion 36 includes a non-adhesive portion 38 which is a surface on the optical sheet 20 side and does not exhibit adhesiveness at least at the tip (see FIG. 2). In the example of FIG. 1, the entire protruding portion 36 is a non-adhesive portion 38, and the entire area of the adhesive sheet 28 facing the optical sheet 20 is a non-adhesive portion 38. The non-adhesive part 38 is a layer that covers the second adhesive layer 34. For example, the non-adhesive portion 38 can be formed with ink. The formation can be performed by printing (such as an inkjet method or screen printing). The ink preferably does not contain a conductive material.

  According to this embodiment, since the non-adhesive part 38 in the protrusion part 36 of the adhesive sheet 28 does not adhere to the optical sheet 20, the influence of the adhesive sheet 28 on the optical sheet 20 can be avoided.

  FIG. 3 is a diagram illustrating an adhesive sheet according to the first modification. In this example, the first adhesive layer 132 is provided on the first surface 140 of the base material 130 and the second adhesive layer 134 is provided on the second surface 142, which is the same as the above embodiment. However, the second adhesive layer 134 is provided only on a part of the second surface 142 of the base material 130. That is, the second adhesive layer 134 is provided in a region of the base material 130 facing the frame 22 (see FIG. 1). And the non-adhesion part 138 is provided in the area | region (area | region which opposes the optical sheet 20 (refer FIG. 1)) which does not oppose the flame | frame 22 (refer FIG. 1) of the 2nd surface 142 of the base material 130. FIG. The non-adhesive part 138 is a layer formed by curing the second adhesive layer 134. For example, the second adhesive layer 134 is cured by irradiating with ultraviolet rays. Also in this example, the same effect as the above-described embodiment can be achieved.

  FIG. 4 is a view showing an adhesive sheet according to the second modification. This example is the same as the above embodiment in that the first adhesive layer 232 is provided on the first surface 240 of the substrate 230 and the second adhesive layer 234 is provided on the second surface 242. However, the second adhesive layer 234 is provided only on a part of the second surface 242 of the substrate 230. That is, the second adhesive layer 234 is provided in a region facing the frame 22 (see FIG. 1) of the base material 230. And the base material 230 is exposed in the area | region (area | region which opposes the optical sheet 20 (refer FIG. 1)) which does not oppose the flame | frame 22 (refer FIG. 1) of the 2nd surface 242 of the base material 230, and this is non-adhesion. Part 238. That is, the second adhesive layer 234 is provided avoiding the region facing the optical sheet 20 (see FIG. 1) of the base material 230, and the region avoided by the second adhesive layer 234 of the base material 230 is the non-adhesive portion. 238. The non-adhesive part 238 may be formed by removing the part after adhering the second adhesive layer 234 to the entire second surface 242 of the substrate 230. Also in this example, the same effect as the above-described embodiment can be achieved.

  The present invention is not limited to the embodiment described above, and various modifications are possible. For example, the configuration described in the embodiment can be replaced with a substantially the same configuration, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose.

  DESCRIPTION OF SYMBOLS 10 Liquid crystal display panel, 12 Substrate, 14 Polarizing plate, 16 Backlight, 18 Light guide plate, 20 Optical sheet, 22 Frame, 24 Reflective sheet, 26 Wall part, 28 Adhesive sheet, 30 Base material, 32 1st adhesive layer, 34 2nd adhesion layer, 36 protrusion part, 38 non-adhesion part, 130 base material, 132 1st adhesion layer, 134 2nd adhesion layer, 138 non-adhesion part, 140 1st surface, 142 2nd surface, 230 base material, 232 1st adhesion layer, 234 2nd adhesion layer, 238 Non-adhesion part, 240 1st surface, 242 2nd surface.

Claims (8)

A liquid crystal display panel;
A backlight facing the liquid crystal display panel;
A frame that arranges the backlight on the inside and supports an end of the liquid crystal display panel;
An adhesive sheet that adheres to the end of the liquid crystal display panel and the frame;
Including
The backlight has an optical sheet on the side closest to the liquid crystal display panel,
The pressure-sensitive adhesive sheet has a protruding portion protruding between the liquid crystal display panel and the optical sheet,
The liquid crystal display device, wherein the protruding portion of the adhesive sheet includes a non-adhesive portion which is a surface on the optical sheet side and does not exhibit adhesiveness at least at a tip. The liquid crystal display device according to claim 1,
The liquid crystal display device according to claim 1, wherein the entire protruding portion is the non-adhesive portion. The liquid crystal display device according to claim 1,
The liquid crystal display device characterized in that the entire area of the adhesive sheet facing the optical sheet is the non-adhesive part. In the liquid crystal display device according to any one of claims 1 to 3,
The adhesive sheet includes a base material, a first adhesive layer attached to the liquid crystal display panel side of the base material, and a second adhesive layer attached to the frame side of the base material. A liquid crystal display device. The liquid crystal display device according to claim 4,
The liquid crystal display device, wherein the non-adhesive portion is a layer covering the second adhesive layer. The liquid crystal display device according to claim 5,
The liquid crystal display device, wherein the non-adhesive portion is made of ink. The liquid crystal display device according to claim 4,
The second adhesive layer is provided avoiding a region facing the optical sheet of the base material,
The liquid crystal display device characterized in that a region of the base material that the second adhesive layer avoids is the non-adhesive portion. The liquid crystal display device according to claim 4,
The second adhesive layer is provided in a region of the base material facing the frame;
The liquid crystal display device according to claim 1, wherein a layer formed by curing the second adhesive layer is provided as the non-adhesive portion in a region facing the optical sheet of the base material.

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