JP4093756B2 - Liquid crystal display element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display element, and more particularly to a liquid crystal display element having a light guide plate on which an optical film and a reflection plate are disposed.
[0002]
[Prior art]
In general, a liquid crystal display element for displaying information such as a specific figure or a character is often used as a display element of a computer, a mobile phone or the like. This liquid crystal display element has a liquid crystal display panel for selectively applying a voltage to a predetermined portion of a pair of transparent substrates filled with liquid crystal in the middle to display information such as specific figures and characters.
[0003]
For example, in the case of a backlight type liquid crystal display element, a light guide plate is disposed on the back side of the liquid crystal display panel, and one side of the light guide plate is irradiated with light on the side of the light guide plate. A light source is disposed. Further, on the front side of the light guide plate, an optical film such as a diffusion plate and a prism sheet for diffusing light incident on the light guide plate from the light source is disposed, and on the back side of the light guide plate, A reflection plate for reflecting light incident on the light guide plate from the light source to the front side is disposed, and the optical film and the reflection plate are fixed to the light guide plate. As means for fixing the light guide plate to the optical film and the reflection plate, generally, means for screwing the optical film and the reflection plate to the light guide plate using a plurality of screws has been used.
[0004]
[Problems to be solved by the invention]
However, such a liquid crystal display element is desired to be thinned, and particularly when used in a mobile phone or the like, it is intended to be thinned in units of several microns. When using screws as a fixing means between the reflector and the light guide plate, the thickness dimension of the liquid crystal display element is restricted by the length dimension of the screws, and it is difficult to reduce the thickness. It was.
[0005]
Further, as another fixing means, for example, a plurality of locking claws are formed on the light guide plate, a locking hole corresponding to each locking claw is formed on the optical film and the reflection plate, and each locking claw is locked. Means for fixing the optical film and the reflection plate to the light guide plate by locking them in the holes is also conceivable. However, when a liquid crystal display element provided with a light guide plate or the like fixed by this means is used for, for example, a mobile phone, the locking claw is released from the locking hole due to an impact such as dropping. However, there is a problem that the optical film and the reflection plate are detached from the light guide plate.
[0006]
Furthermore, as another fixing means, there is also a means of attaching an optical film and a reflection plate to a light guide plate with a double-sided adhesive sheet. Currently, this double-sided adhesive sheet is generally used with a thickness of 0.03 mm. Yes. However, when the optical film or the like is fixed to the light guide plate using the double-sided adhesive sheet, the dimension of the gap between the optical film and the reflective plate and the light guide plate is equal to the thickness dimension of the double-sided adhesive sheet. As a result, the liquid crystal display element cannot be made thinner.
[0007]
The present invention has been made in view of these points, and an object of the present invention is to provide a liquid crystal display element capable of further reducing the thickness of the liquid crystal display element.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the liquid crystal display element according to the first aspect of the present invention, a light guide plate is disposed on the back side of the liquid crystal display panel, and a reflector is disposed on the back side of the light guide plate. In the liquid crystal display element in which a light source is disposed on one side of the first light guide plate , a first sheet groove for disposing a first double-sided adhesive sheet is formed on the back side of the light guide plate . The depth dimension of the groove is smaller than the thickness dimension of the first double-sided adhesive sheet, and the reflection plate is fixed to the light guide plate without contacting the surface of the reflection plate and the back side of the light guide plate. It is characterized by making it.
[0009]
According to the first aspect of the present invention, by arranging the double-sided adhesive sheet in the sheet groove, a gap smaller than the thickness dimension of the double-sided adhesive sheet can be obtained without bringing the reflecting plate into contact with the light guide plate. it is possible to fix the light guide plate and the reflection plate with a dimension.
[0010]
In the liquid crystal display element according to the second aspect of the present invention, an optical film is disposed between the liquid crystal display panel and the light guide plate, and a second double-sided adhesive sheet is disposed on the surface of the light guide plate. Grooves are formed as in the second sheet, the depth dimension of the second sheet groove is smaller than the thickness dimension of the second double-sided adhesive sheet, and the back surface of the optical film and the front surface of the light guide plate The optical film is fixed to the light guide plate without contact .
[0011]
According to the second aspect of the present invention, by arranging the double-sided adhesive sheet in the sheet groove, a gap smaller than the thickness dimension of the double-sided adhesive sheet can be obtained without bringing the reflector into contact with the optical film. The light guide plate and the optical film can be fixed with dimensions.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a liquid crystal display device according to the present invention will be described with reference to FIGS.
[0013]
FIG. 1 is a perspective view showing a liquid crystal display element according to an embodiment. As shown in FIG. 1, the liquid crystal display element 1 includes a liquid crystal display panel 12 and a backlight unit 4.
[0014]
The backlight unit 4 has a light source 2 for irradiating irradiation light, and a light guide plate 3 is disposed on one side of the light source 2. The light guide plate 3 is configured such that the irradiation light emitted from the light source 2 is incident from one side thereof.
[0015]
In addition, as shown in FIG. 2, sheet grooves 6 for arranging the double-sided adhesive sheet 5 are formed on the front and back surfaces of the light guide plate 3. As shown in FIG. 3, these sheet grooves 6 are non-display areas when the display area is the display area of the liquid crystal display element 1, and one side on which the light source 2 of the light guide plate 3 is provided. The side portions 3b and 3c which are orthogonal to the side 3a are formed so as to be parallel to the side sides 3b and 3c. Further, the depth dimension of the sheet groove 6 is shorter than the thickness dimension of the double-sided adhesive sheet 5 disposed in the sheet groove 6. For example, the thickness dimension of the double-sided adhesive sheet is 0. In the case of 0.03 mm, the groove for each sheet has a depth dimension of 0.02 to 0.025 mm. One surface of the double-sided adhesive sheet 5 disposed in each sheet groove 6 is adhered to the bottom surface of each sheet groove 6.
[0016]
Further, on the front side of the light guide plate 3, an optical film 8 such as a diffusion plate or a prism sheet for diffusing the irradiation light emitted from the light source 2 is disposed, and the back surface of the optical film 8 is the surface of the optical film 8. The light guide plate 3 is fixed to the light guide plate 3 by being attached to the other surface of the double-sided adhesive sheet 5 disposed in the sheet groove 6 formed on the surface of the light guide plate 3. Further, on the back side of the light guide plate 3, a reflection plate 9 that reflects the irradiation light emitted from the light source 2 to the front side is disposed, and the surface of the reflection plate 9 is the back surface of the light guide plate 3. It is fixed to the light guide plate 3 by being attached to the other surface of the double-sided adhesive sheet 5 disposed in the sheet groove 6 formed in the above. In the present embodiment, only one optical film 8 is provided on the surface of the light guide plate 3, but the present invention is not limited to this. For example, a diffusion plate is provided on the surface of the light guide plate. A plurality of optical films 8 may be provided such that two prism sheets are laminated on the surface of the diffusion plate.
[0017]
Further, the outer side of the light guide plate 3 where the sheet groove 6 is formed is formed so as to protrude in the front and back directions so as to cover both side edges of the optical film 8 and the reflection plate 9. .
[0018]
The liquid crystal display panel 12 has a glass substrate 11 as a pair of transparent substrates, and a transparent electrode and an alignment film (not shown) are provided on the surfaces of the glass substrate 11 facing each other. In addition, a sealant 13 is applied to the peripheral portions of the surfaces of the pair of glass substrates 11 facing each other, and the pair of glass substrates 11 is integrally formed. Spacers 14 and liquid crystals 15 are disposed. The liquid crystal display panel 12 displays information such as specific figures and characters by selectively applying a voltage to a predetermined portion of the transparent electrode.
[0019]
Next, the operation of this embodiment will be described.
[0020]
First, one surface of the double-sided adhesive sheet 5 is adhered to the bottom surface of each sheet groove 6 on the back surface of the light guide plate 3. Next, while aligning the reflecting plate 9 and the light guide plate 3, the reflecting plate 9 is placed so that the front surface of the reflecting plate 9 faces the back surface of the light guiding plate 3. And the other surface of each double-sided adhesive sheet 5 are stuck together, thereby fixing the light guide plate 3 and the reflection plate 9.
[0021]
Further, one surface of the double-sided adhesive sheet 5 is adhered to the bottom surface of each sheet groove 6 on the surface of the light guide plate 3. Next, while aligning the optical film 8 and the light guide plate 3, the optical film 8 is placed so that the back surface of the optical film 8 faces the surface of the light guide plate 3. And the other surface of each double-sided adhesive sheet 5 are stuck together, thereby fixing the light guide plate 3 and the optical film 8.
[0022]
A light source 2 is provided on one side of the light guide plate 3 to which the reflecting plate 9 and the optical film 8 are fixed to form a backlight unit 4, and the backlight unit 4 is provided on the back side of the liquid crystal display panel 12. Thus, the liquid crystal display element 1 is completed.
[0023]
According to the present embodiment, one surface of the double-sided adhesive sheet 5 is adhered to the bottom surface of the sheet groove 6, and the reflective plate 9 or the like is adhered to the other surface of the double-sided adhesive sheet 5, whereby the light guide plate 3 and the Since the reflector 9 can be fixed, when the depth dimension of the sheet groove 6 is 0.025 mm, even when the double-sided adhesive sheet 5 having a thickness dimension of 0.03 mm is used, The light guide plate 3, the optical film 8, and the reflection plate 9 can be fixed by a gap size of 0.005 mm.
[0024]
Moreover, since the depth dimension of the sheet groove 6 is shorter than the thickness dimension of the double-sided adhesive sheet 5, the optical film 8 and the reflector 9 are brought into contact with the light guide plate 3. It can be made to contact | abut to the other surface of the said double-sided adhesive sheet 5, and to make it stick on the other surface of the said double-sided adhesive sheet 5, without making it.
[0025]
Therefore, when a 0.03 mm double-sided adhesive sheet is conventionally used, according to this embodiment, 0.005 mm compared to the case where the light guide plate and the reflecting plate are fixed with a thickness of 0.03 mm. The light guide plate 3 and the reflecting plate 9 can be fixed by the gap size of the liquid crystal display element 1, the thickness of the liquid crystal display element 1 and the sheet groove 6 between the light guide plate 3, the optical film 8 and the reflecting plate 9. Therefore, the liquid crystal display element 1 can be further reduced in thickness.
[0026]
In addition, since the reflecting plate 9 and the like can be brought into contact with the other surface of the double-sided adhesive sheet 5 without coming into contact with the light guide plate 3, the reflecting plate 9 and the like can be reliably attached to the other surface of the double-sided adhesive sheet 5. By sticking, the light guide plate 3 and the reflection plate 9 can be firmly and securely fixed.
[0027]
4 and 5 show the shapes of the sheet grooves of the other two light guide plates arranged in the liquid crystal display element according to the present invention.
[0028]
As shown in FIG. 4, the shape of the sheet groove 18 of one light guide plate 17 is a non-display area of the light guide plate 17 and excludes one side 17 a close to the light source 19 of the light guide plate 17. The three side edges 17b, 17c and 17d are continuously formed so as to be parallel to the side edges 17b, 17c and 17d. Further, as shown in FIG. 5, the shape of the sheet groove 22 of the other light guide plate 21 is a non-display area of the light guide plate 21 and is formed on each side 21a, 21b, 21c, 21d portion of the light guide plate 21. Are formed continuously so as to be parallel to the side sides 21a, 21b, 21c, 21d.
[0029]
According to the shape of the sheet grooves 18 and 22, since the area where the sheet grooves 18 and 21 are formed is wide, the adhesion area between the light guide plates 17 and 21 and the optical film and the reflection plate is increased. Can be spread.
[0030]
Therefore, the light guide plates 17, 21 and the optical film and the reflection plate can be more strongly fixed.
[0031]
However, when a sheet groove is formed on one side of the back surface of the light guide plate that is close to the light source, the light emitted from the light source to one side of the light guide plate is reflected on the viewing side by the reflector. When the light is reflected in the direction, the reflected light reflected in the portion of the reflector where the sheet groove formed on one side of the light guide plate is located becomes strong light from the light guide plate to the liquid crystal display panel. It will be emitted to the side. For this reason, since this liquid crystal display element cannot obtain a favorable display, the sheet groove formed on the back surface of the light guide plate is close to the light source in the light guide plate as shown in FIGS. Preferably, it is formed on a side portion other than the one side portion.
[0032]
In addition, in each said embodiment, although each sheet | seat groove | channel 6, 18, 22 is formed in both surfaces of the surface of a light-guide plate 3, 17, 21, it is not limited to this. For example, one of a diffusion plate on the front surface of the light guide plate and a reflection plate on the back surface is disposed, and each sheet groove is formed on one surface on which the diffusion plate or the reflection plate is disposed. It may be. Further, a diffusion plate may be disposed on the front surface of the light guide plate, and a reflection plate may be disposed on the back surface, and each sheet groove may be formed on one surface of the light guide plate.
[0033]
The present invention is not limited to the above-described embodiment, and various modifications can be made as necessary.
[0034]
【The invention's effect】
As described above, according to the liquid crystal display element according to the first aspect of the present invention, the light guide plate and the reflection plate can be fixed with a gap dimension smaller than the thickness dimension of the double-sided adhesive sheet. The display element can be thinned, and the reflector is brought into contact with the double-sided adhesive sheet without coming into contact with the light guide plate. The reflector is securely attached to the double-sided adhesive sheet, and the light guide plate and the reflector are It can be firmly and securely fixed.
[0035]
Further, according to the liquid crystal display element of the invention described in claim 2, since the light guide plate and the optical film can be fixed with a gap dimension smaller than the thickness dimension of the double-sided adhesive sheet, the liquid crystal display element is thin. The optical film is brought into contact with the double-sided adhesive sheet without making contact with the light guide plate, and the optical film is securely attached to the double-sided adhesive sheet, and the light guide plate and the optical film are strongly and reliably attached. Can be fixed.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an embodiment of a liquid crystal display element according to the present invention. FIG. 2 is a cross-sectional view showing a liquid crystal display element cut along an AA cutting line in FIG. FIG. 4 is a conceptual diagram showing the shape of a sheet groove formed on the light guide plate of the element. FIG. 4 is a conceptual diagram showing an embodiment of the shape of another sheet groove formed on the light guide plate of the liquid crystal display element according to the present invention. FIG. 5 is a conceptual diagram showing an embodiment of the shape of another sheet groove formed in the light guide plate of the liquid crystal display element according to the present invention.
DESCRIPTION OF SYMBOLS 1 Liquid crystal display element 2 Light source 3 Light guide plate 5 Double-sided adhesive sheet 6 Sheet groove 8 Optical film 9 Reflecting plate 12 Liquid crystal display panel

Claims (2)

In a liquid crystal display element in which a light guide plate is disposed on the back side of the liquid crystal display panel , a reflection plate is disposed on the back side of the light guide plate, and a light source is disposed on one side of the light guide plate.
A first sheet groove for arranging the first double-sided adhesive sheet is formed on the back side of the light guide plate , and the depth dimension of the first sheet groove is determined by the thickness of the first double-sided adhesive sheet. A liquid crystal display element having a dimension smaller than the dimension, wherein the reflector is fixed to the light guide plate without contacting the surface of the reflector and the back side of the light guide plate . An optical film is disposed between the liquid crystal display panel and the light guide plate, and a groove is formed on the surface of the light guide plate as a second sheet for disposing a second double-sided adhesive sheet. The depth dimension of the groove is smaller than the thickness dimension of the second double-sided adhesive sheet, and the optical film is fixed to the light guide plate without bringing the back surface of the optical film into contact with the front surface of the light guide plate. The liquid crystal display element according to claim 1.

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