JP4659960B2 - Mounting structure of liquid crystal display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mounting structure of a backlight-integrated liquid crystal display device provided with a backlight, and more particularly to a mounting structure of a liquid crystal display device characterized by alignment between a light guide and a black mask sheet.
[0002]
[Prior art]
First, an example of the configuration of a conventional liquid crystal display device will be described with reference to FIGS.
[0003]
FIG. 3 shows a liquid crystal display element 10 capable of color display mounted on a liquid crystal display device, and has two transparent substrates 1A and 1B arranged substantially in parallel with a distance therebetween. The outer periphery between the two transparent substrates 1A and 1B is sealed with a sealing material 2, and a transparent common electrode 3A is disposed in close contact with the lower surface of one transparent substrate 1A located above. A light shielding film 4 is disposed below the transparent common electrode 3A so as to cover a non-display portion of the liquid crystal display element 10.
[0004]
Below the light-shielding film 4, an alignment film 6A that controls the alignment of liquid crystal molecules according to the voltage applied between the electrodes is disposed in close contact with the transparent substrate 1A. A polarizing plate 7A is provided.
[0005]
On the other hand, a transparent segment electrode 3B is disposed on the upper surface of the transparent substrate 1B located below. A color filter film 5 is disposed above the transparent segment electrode 3B, and an alignment film 6B is disposed on the color filter film 5 so as to be in close contact therewith. Further, a polarizing plate 7B is disposed on the lower surface of the transparent substrate 1B.
[0006]
A liquid crystal 8 is sealed in a sealed space surrounded by the transparent substrates 1A and 1B and the sealing material 2, and a plurality of spherical or columnar spacers 9 interposed between the alignment films 6A and 6B. The transparent substrates 1A and 1B are held at a constant interval.
[0007]
The transparent segment electrode 3B on the upper surface of the transparent substrate 1B is led out on the lower surface of the transparent substrate 1A via a conductive member (not shown) contained in the sealing material 2 and the like. Each lead terminal 3C of each electrode 3A, 3B is formed in the right end part in FIG. 1 of the lower surface of this transparent substrate 1A.
[0008]
On the other hand, an electric circuit 13 is formed on the base film 12 of the flexible wiring board 11 shown in FIG. 4, and the electrodes 3A and 3B are connected to lead terminals (not shown) formed at the ends of the electric circuit. Each lead terminal 3C is connected. An LSI 14 for controlling the liquid crystal display element 10 is connected to the electric circuit 13 of the flexible wiring board 11. The flexible wiring board 11 is formed with a curved portion 15 to reduce the plane area of the liquid crystal display device, and then extends below the liquid crystal display element 10 as shown in FIG. It is electrically connected to the power supply side wiring board 16 having rigidity positioned below the liquid crystal display element 10.
[0009]
Meanwhile, in the backlight-integrated liquid crystal display device, a light source 17 of a backlight such as a light emitting diode or a fluorescent lamp is supported on one end of the upper surface of the power supply side wiring substrate 16 facing the liquid crystal display element 10. .
[0010]
A light guide body 20 having a light guide plate 18 made of a material such as acrylic and a guide frame 19 for supporting the light guide plate 18 is mounted on the upper surface of the power supply side wiring board 16. At the time of mounting, the light source 17 is positioned on the side of the end face of the light guide 20. In the liquid crystal display device shown in FIG. 4, a plurality of prism sheets 21 are disposed on the upper surface of the light guide plate 18, and the light guide 20 is configured together with the light guide plate 18 and the guide frame 19. is doing.
[0011]
In the liquid crystal display device, a black black mask sheet 22 that is formed in a frame shape surrounding the display area of the liquid crystal display element 10 and covers the non-display area is disposed on the upper surface of the light guide 20. The liquid crystal display element 10 is disposed and fixed above the black mask sheet 22.
[0012]
[Problems to be solved by the invention]
By the way, conventionally, alignment of the light guide 20 and the black mask sheet 22 at the time of mounting the liquid crystal display device is, for example, cylindrical at four corners of the light guide 20 as shown in FIG. Protrusions 23 are formed, and circular engagement holes 24 are formed at the four corners of the black mask sheet 22 to have the inner diameter substantially the same as the protrusions 23 and fit the protrusions 23. Positioning is performed by fitting the protrusion 23 into the engagement hole 24.
[0013]
However, in this method, an allowable value (tolerance) for fitting the protrusion 23 into the engagement hole 24 is required no matter how the outer shape of the protrusion 23 and the inner diameter of the engagement hole 24 are made equal. The inner diameter of the hole 24 must be designed larger than the outer diameter of the protrusion 23. Therefore, as indicated by an arrow in FIG. 5, the columnar protrusion 23 can move in the engagement hole 24, and thus its position is not fixed. Therefore, the black mask sheet 22 is fixed in a state where it is displaced from the original position with respect to the light guide 20. As a result, a part of the black mask sheet 22 is exposed in the display area of the liquid crystal display device to reduce the display area area, or the liquid crystal display device is not displayed in the display area. The light from the area part enters, causing a problem that only a part is displayed excessively brightly.
[0014]
The present invention has been made in view of such problems, and by appropriately positioning the black mask sheet with respect to the light guide, correctly partition the non-display area and the display area by the black mask sheet, An object of the present invention is to provide a mounting structure of a liquid crystal display device capable of realizing a good liquid crystal display.
[0015]
[Means for Solving the Problems]
In order to achieve the above-described object, the mounting structure of the liquid crystal display device of the present invention has an upper surface edge of a light guide formed in a substantially rectangular shape that irradiates the liquid crystal display element with light from a light source disposed in the liquid crystal display device. A triangular prism-shaped engagement convex portion that projects a tip portion in a side direction opposite to the formation side is formed on the portion, and the outer shape is formed in a substantially rectangular frame shape that covers a non-display area of the liquid crystal display device. The black mask sheet has a triangular shape having a pointed portion having the same angle as the pointed portion of the engaging convex portion, and is formed by notching an engaging concave portion that can be engaged with the engaging convex portion. To do.
[0016]
According to the present invention, it is possible to closely engage the tip end of the engaging convex portion and the tip end portion of the engaging concave portion formed at the same angle.
[0017]
The mounting structure of the liquid crystal display device according to claim 2 of the present invention is the mounting structure of the liquid crystal display device according to claim 1, wherein the engaging protrusion is at least different from the light guide 2. It is formed in the edge part of a side, The said engagement recessed part is formed in the edge part of at least two different sides of the said black mask sheet | seat.
[0018]
According to the present invention, by engaging the engaging concave portion with the engaging convex portion formed at the edge of at least two different sides, the point of the engaging convex portion and the point of the engaging concave portion are In combination with the formation of the same angle, the positional deviation between the light guide and the black mask sheet can be completely prevented.
[0019]
Furthermore, a mounting structure for a liquid crystal display device according to a third aspect of the present invention is the mounting structure for a liquid crystal display device according to the first or second aspect, in which the tip end portion of the engaging convex portion and the engagement portion are arranged. The angle of the tip of the joint recess is in the range of 45 ° to 90 °.
[0020]
According to the present invention, when mounting, light can be concentrated on the apex of the inner corner of the engagement recess, and therefore, the engagement operation between the engagement protrusion and the engagement recess can be easily performed. In addition, the positional deviation between the light guide and the black mask sheet can be more completely prevented.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.
[0022]
This embodiment relates to the alignment of the light guide 20 and the black mask sheet 22 in the mounting structure of the liquid crystal display device, and the structure of members other than the light guide 20 and the black mask sheet 22 of the liquid crystal display device. The mounting method is based on the above-described conventional mounting structure, and the description thereof is omitted. Further, members similar to those of the above-described conventional example will be described with the same reference numerals.
[0023]
In the present embodiment, one edge 25 </ b> A parallel to the end face 20 </ b> B of the light guide 20 is provided at the edge of the upper surface 20 </ b> A of the light guide 20, that is, the edge of the surface facing the liquid crystal display element 10. A triangular prism-like engagement convex portion 25 is formed. Specifically, in the present embodiment, the engaging convex portion 25 is formed on at least two different edge portions of the guide frame 19 that constitutes the light guide 20. In the present embodiment, the light guide is formed. The tip portions 25B are formed at both corners of a pair of opposing sides constituting the guide frame 19 of the body 20 so as to protrude in the opposing side directions. Therefore, in the present embodiment, as shown in FIG. 1, the engagement protrusions 25 are formed at the four corners of the light guide 20. At this time, the opposing angle of the one side surface 25A constituting the pointed end 25B, that is, the pointed end 25B is formed at an acute angle, preferably in the range of 45 ° to 90 °. In this embodiment, it is formed at 60 °.
[0024]
In addition, the black mask sheet 22 formed in a substantially rectangular frame shape has a triangular shape that is the same shape as the planar shape of the engaging convex portion 25 and can be engaged with the engaging convex portion 25. The engaging recess 26 is cut out. In other words, the engaging recess 26 is formed on at least two different edge portions of the outer side of the black mask sheet 22. In the present embodiment, notches are formed at both corners of the pair of opposing sides of the black mask sheet 22 so as to project the tip portions 26B in the opposing side directions.
[0025]
At that time, the inner angle of the tip end portion 26B of the engagement recess 26 formed in the notch is the opposite angle of the one side surface 25A constituting the engagement projection portion 25 formed in a triangular prism shape (the angle of the tip end portion 25B). To be equal to That is, it is an acute angle and is preferably in the range of 45 ° to 90 °.
[0026]
When the liquid crystal display device is mounted, the corresponding engagement concave portions 26 of the black mask sheet 22 are provided for the respective engagement convex portions 25 of the light guide 20 configured as described above. The light guide 20 and the black mask sheet 22 are aligned by engaging the tip ends 25B and 26B of the engagement recess 25 and the engagement recess 26 with each other.
[0027]
At this time, in the present embodiment, the planar shape of the engaging convex portion 25 and the shape of the engaging concave portion 26 are the same triangular shape, and further, on one set of opposing sides of the guide frame 19 of the light guide 20. Since it is formed, the positional relationship between the light guide 20 and the black mask sheet 22 can be regulated by closely engaging the engaging convex portion 25 and the engaging concave portion 26. It is possible to prevent the occurrence of a positional deviation caused by the poor engagement between the engaging convex portion 25 and the engaging concave portion 26.
[0028]
The positional deviation between the light guide 20 and the black mask sheet 22 is coupled with the fact that the planar shapes of the engaging convex portion 25 and the engaging concave portion 26 are triangular, and thus the engaging convex portion. By forming the portion 25 at at least the corners of two different sides of the light guide 20, it can be completely prevented.
[0029]
Further, in the present embodiment, the sharpened end portions 25B and 26B of the engaging convex portion 25 and the engaging concave portion 26 are formed at an acute angle of 60 °, so that the inner angle of the engaging concave portion 26 can be reduced during mounting. Light can be concentrated at the apex. Therefore, it becomes easy to visually recognize the engagement convex part 25 and the engagement concave part 26, the alignment operation can be easily performed, and the accuracy can be improved.
[0030]
In addition, if the angles of the tip portions 25B and 26B are obtuse angles, positional deviation is likely to occur in the spreading direction of the two sides constituting the tip portions 25B and 26B, and if the angle is excessively acute, Since the operation of engaging the engaging convex portion 25 and the engaging concave portion 26 becomes difficult, it can be said that an angle in the range of 45 ° to 90 ° is a suitable angle in order to obtain the above-described effect. .
[0031]
In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.
[0032]
For example, in the above-described embodiment, the light guide 20 includes the so-called light guide plate 18, the guide frame 19, and the prism sheet 21, but the light guide plate 18 is the only essential component of the light guide 20. In addition, it is possible to adopt a configuration in which the engagement convex portion 25 is formed at the edge of the so-called light guide plate 18. In addition, when arrange | positioning the prism sheet 21, the number of sheets is not restricted to 3 sheets of this embodiment, One sheet may be sufficient.
[0033]
Further, as described above, the black mask sheet 22 has the light guide 20, specifically the guide frame 19 of the light guide 20, attached to the lower surface thereof, and the liquid crystal display element 10 having the above-described configuration on the upper surface. Specifically, the lower surface of the polarizing plate 7B is disposed and fixed. Therefore, an adhesive member such as a double-sided tape is previously pasted on both the upper and lower surfaces of the black mask sheet 22, and the black mask sheet 22, the light guide 20 and the liquid crystal display element 10 are fixed during mounting. You may comprise so that the operation | work of arrangement | positioning can be performed easily.
[0034]
Furthermore, it is needless to say that the arrangement positions of the engagement convex portions 25 and the engagement concave portions 26 are not limited to the arrangement positions of the above-described embodiment, and FIG. An example of the black mask sheet 22 in the case where the combined recess 26 is formed will be described.
[0035]
【The invention's effect】
As described above, according to the present invention, the problem of misalignment of the black mask sheet with respect to the light guide can be solved, and the non-display area in the liquid crystal display device can be appropriately covered with the black mask sheet. In addition, a liquid crystal display device capable of obtaining a certain display quality in the display area can be easily manufactured.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a main part of a liquid crystal display device for explaining a mounting structure involving positioning of a light guide and a black mask sheet of the present invention. FIG. 2 is engaged at a position different from the embodiment of FIG. FIG. 3 is a cross-sectional view showing an example of the structure of a color liquid crystal display element. FIG. 4 is a cross-sectional view showing an example of a liquid crystal display device on which the liquid crystal display element of FIG. 3 is mounted. FIG. 5 is an explanatory diagram showing problems in positioning between a conventional light guide and a black mask sheet.
DESCRIPTION OF SYMBOLS 10 Liquid crystal display element 11 Flexible wiring board 12 Base film 13 Electric circuit 15 Curved part 16 Electrode side wiring board 17 Light source 18 Light guide plate 19 Guide frame 20 Light guide 20A Upper surface 20B End surface 21 Prism sheet 22 Black mask sheet 23 Projection 24 Joint hole 25 Engagement convex part 25A One side surface 25B Point end part 26 Engagement recess part 26B Point end

Claims (3)

A triangular prism shape with a pointed portion protruding in the direction of the side opposite to the side of the light guide formed in a substantially rectangular shape that irradiates the liquid crystal display element with light from a light source disposed in the liquid crystal display device A black mask sheet formed in a substantially rectangular frame shape covering the non-display area of the liquid crystal display device , and a pointed portion having an angle equal to the pointed portion of the engaging convex portion A mounting structure for a liquid crystal display device, characterized in that an engagement concave portion that has a triangular shape and that can be engaged with the engagement convex portion is cut out.   2. The engagement convex portion is formed at an edge portion of at least two different sides of the light guide, and the engagement concave portion is formed at an edge portion of at least two different sides of the black mask sheet. A mounting structure of the liquid crystal display device according to 1.   The mounting structure of the liquid crystal display device according to claim 1, wherein an angle between a tip portion of the engaging convex portion and a tip portion of the engaging concave portion is in a range of 45 ° to 90 °. .

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