JP2005189892A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with which downsizing and simplification of manufacturing processes are possible, a back light panel, and a method for manufacturing a liquid crystal display device. <P>SOLUTION: The liquid crystal display device includes a liquid crystal panel 10 constituted by interposing a liquid crystal between a pair of substrates 12 and 14, an electrode 12a disposed in the inner side of the substrate 12, and a back light panel 20 of an edge system for making the light of a light emitting section 22 arranged at the end to a surface light source. The substrate 12 is arranged to be displaced from the substrate 14 to form a projecting part 12a and the electrode 12b is exposed on the projecting part 12a. The light emitting section 22 of the back light 20 is arranged in a region facing the projecting part 12a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, a backlight panel, and a method for manufacturing a liquid crystal display device.

  Since the liquid crystal display is a non-luminous display, a backlight is used so that it can be used even in a dark place. There is an edge type backlight. This edge type backlight has a light source provided at the side edge of the illumination surface, so that the outer dimensions are large. In particular, in a backlight in which the shape of the reflection surface is devised to convert a plurality of point light sources into a surface light source, a certain distance is required from the point light source to the illumination surface, so that the outer dimensions are further increased. This hinders downsizing the liquid crystal display device.

  Alternatively, when attaching the backlight to other members, a spacer was placed under the backlight to avoid electrical components, etc., but this process not only increased the manufacturing process but also increased the positioning. It was difficult to do.

Alternatively, when a long cable is cut to a predetermined length and connected to a circuit board, it is difficult to cut the cable to an accurate length. If the dimensions are too short, the connection cannot be made. If the dimensions are too long, sagging occurs and takes up space, which hinders downsizing the liquid crystal display device.
JP-A-8-166588 Shokai 55-46268 JP-A-8-181749

  The present invention solves the above-described problems, and an object of the present invention is to provide a liquid crystal display device, a backlight panel, and a method for manufacturing the liquid crystal display device that can be miniaturized or that can simplify the manufacturing process. There is.

A liquid crystal display device according to the present invention includes a liquid crystal panel in which liquid crystal is sandwiched between a pair of substrates, a pair of electrodes provided on opposite surfaces of the pair of substrates, and at least one light source disposed at an end. Including an edge-type backlight panel that converts to a surface light source,
The pair of substrates are arranged offset from each other to form a protrusion, and one of the electrodes is exposed on the protrusion,
The light source of the backlight panel is disposed in a region facing the protruding portion.

  In the present invention, the electrode is exposed on the protruding portion, thereby facilitating electrical connection with the outside. The protruding portion is a region where the liquid crystal is not sandwiched because the pair of substrates are formed so as to be displaced from each other. Therefore, the protrusion is formed outside the liquid crystal display region. Further, since the protrusion is formed, the distance from the side edge of the protrusion to the liquid crystal display region is increased.

  On the other hand, the edge-type backlight panel needs some distance between the light source and the surface light source area. Therefore, the distance of the protruding portion can be effectively utilized by arranging the light source in the region facing the protruding portion. Thus, the outer shape of the liquid crystal display device can be minimized.

The backlight panel has a plurality of point light sources, an effective light emitting unit that is uniformly converted into a surface light source, and a transition region from the point light source to the effective light emitting unit,
At least a part of the transition region and the point light source may be arranged in a region facing the protrusion.

  As described above, in the configuration in which a plurality of point light sources are converted into surface light sources, since there is a distance between adjacent point light sources, the transient region becomes longer than when a line light source is converted into a surface light source. Therefore, at this time, it is effective in minimizing the outer shape to arrange at least a part of the transient region and the point light source in the region facing the protrusion.

The present invention has a light source disposed at the end, and a light guide plate that guides light from the light source and emits the light in one surface direction to form a surface light source,
The other surface of the light guide plate is processed to reflect the light from the light source in the direction of the one surface, and is integrated with a region other than the effective light-emitting portion that uniformly converts to a surface light source. An edge-type backlight panel in which a support portion is formed is provided.

  In the present invention, the light source at the end is converted into a surface light source by the light guide plate, and light is emitted in the surface direction. For example, light can be reflected in the surface direction by applying Fresnel mirror processing or embossing to the back surface of the light guide plate.

  Moreover, in this invention, the support part is integrally formed in the backlight panel. Since this support portion is formed in a region other than the effective light emitting portion where a uniform surface light source is required, it does not hinder proper reflection of light. Thus, since the backlight panel according to the present invention has the support portion, it can be easily attached to other members.

  The support part preferably has a positioning part with another member. By doing so, not only attachment but also positioning can be performed easily.

  The liquid crystal display device according to the present invention includes the above-described backlight panel, the liquid crystal panel is attached to the one surface, and the circuit board is attached to the other surface.

  According to the present invention, the circuit board is attached to the surface of the backlight panel where the support portion is formed. Therefore, the circuit board can be attached by effectively utilizing the space formed between the support portion and the surface of the backlight panel. Thus, the thickness of the liquid crystal display device can be reduced.

The present invention includes a step of obtaining a connection member by cutting a long cable for electrical connection longer than a required dimension;
Electrically connecting the end portion to the circuit board in a direction different from the predetermined arrangement direction;
Bending the connection member and directing the connection member in the predetermined arrangement direction;
Adjusting the bending position of the connecting member and adjusting the arrangement length of the connecting member;
The manufacturing method of the liquid crystal display device containing this is provided.

  According to the present invention, even if there is an error in the length of the connecting member, the arrangement length can be adjusted only by adjusting the bending position. Thus, by adjusting the arrangement length of the connection member, it is possible to improve workability when the tip of the connection member is connected to another member. Further, since the slack of the connecting member can be minimized, the outer shape of the liquid crystal display device can be reduced.

  Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is an exploded perspective view schematically showing the liquid crystal display device according to the embodiment of the present invention. FIG. 1 is a side sectional view of the liquid crystal display device according to this embodiment. As shown in these drawings, the liquid crystal display device includes a liquid crystal panel 10, a backlight panel 20, and a circuit board 30.

  The liquid crystal panel 10 is configured such that liquid crystal (not shown) is sandwiched between a pair of substrates 12 and 14 made of glass, and polarizing plates 16 and 18 are attached to the outer surfaces of the substrates 12 and 14. One substrate 12 has a protruding portion 12 a that protrudes in a state shifted from the other substrate 14, and the other substrate 14 has a protruding portion 14 a that protrudes in a state shifted from one substrate 12.

  A pair of electrodes 12b and 14b for driving the liquid crystal are provided on the opposing surfaces of the substrates 12 and 14, respectively. The ends of the electrodes 12b and 14b are exposed on the protrusions 12a and 14a.

  The liquid crystal panel 10 and the backlight panel 20 are bonded and fixed by, for example, a tape-like member provided with an adhesive layer on both sides, which is indicated by hatching in FIG. At this time, the tape-shaped member is preferably provided in a region other than the region corresponding to the effective light emitting portion 28 (outside the region). Furthermore, although the inside is a space in this embodiment, any state may be used as long as it does not block the optical path.

  The backlight panel 20 includes a light emitting unit 22, a light guide plate unit 24, and a support unit 26. The light emitting unit 22 includes a light emitting element 22a as a plurality of point light sources. The light guide plate portion 24 is transparent so that light from the light emitting element 22a can be guided. In addition, one surface of the light guide plate portion 24 is subjected to Fresnel mirror processing so that light can be emitted to the other surface (see FIG. 1). Further, a reflection plate 24a is attached to the surface subjected to the Fresnel mirror processing to prevent light leakage.

  Thus, the backlight panel 20 is of an edge type. Therefore, the light emitting unit 22 is provided to project to the side of the light guide plate unit 24 that emits light. Further, as described above, the projections 12a and 14a are also formed on the substrates 12 and 14 of the liquid crystal panel 10 so as to protrude to the side of the region sandwiching the liquid crystal.

  Therefore, in the present embodiment, the outer dimensions are minimized by arranging the light emitting portion 22 so as to face the protruding portion 12a. That is, the projecting part 12a of the liquid crystal panel 10 and the light emitting part 22 of the backlight panel 20 are projected in the same direction, so that no useless space is generated.

  In the present embodiment, light from the plurality of light emitting elements 22 a is converted into a surface light source in the light guide plate portion 24. Therefore, a certain distance is required to convert the light from the light emitting element 22a as a point light source into a surface light source.

  That is, since there is a distance between the adjacent light emitting elements 22a and 22a, it cannot be a surface light source in the vicinity of the light emitting element 22a. As shown in FIG. 1, a transition region 29 having a length l2 is required until reaching the effective light emitting portion 28 (length l1) that requires a uniform surface light source.

  As described above, since the backlight panel 20 converts the point light source into a surface light source, the distance protruding outward from the effective light emitting unit 28 becomes long. Therefore, disposing the portion protruding from the effective light emitting portion 28 so as to face the protruding portion 12a of the liquid crystal panel 10 is effective in reducing the external dimensions.

  The support portion 26 is formed on the surface of the light guide plate portion 24 that has been subjected to the above-described Fresnel mirror processing, so that the backlight panel 20 can be easily attached to other members. Further, since the support portion 26 is formed integrally with the light guide plate portion 24, it is possible to improve workability and reduce manufacturing costs compared to the case where a spacer or the like is used as a separate member. Furthermore, since the support part 26 is formed avoiding the effective light emission part 28, it does not disturb the Fresnel mirror processing. That is, it does not prevent the light from the light emitting element 22a from becoming a surface light source.

  Furthermore, since the support part 26 has the protrusion 26a in the lower end, if a hole is formed in another member, positioning can be performed easily. A plurality of protrusions 26a are preferably provided.

  Next, the circuit board 30 includes a driving circuit and a power supply circuit for the liquid crystal panel 10 and the light emitting element 22a. Therefore, the circuit board 30 and the liquid crystal panel 10 are electrically connected by thermocompression bonding the heat seal 32. Alternatively, instead of the heat seal 32, a TAB on which a semiconductor chip is mounted may be used, and the TAB may be electrically connected to the liquid crystal panel 10 by thermocompression bonding using an anisotropic conductive film. Good. The circuit board 30 and the light emitting element 22a are electrically connected by soldering the leads 34.

  The circuit board 30 is a surface on which the support part 26 is formed, and is attached so as to avoid the support part 26. Therefore, when the backlight panel 20 is attached to another member, the space formed between the backlight panel 20 and the support portion 26 can be effectively utilized.

  A flat cable 36 is soldered to the circuit board 30 for further electrical connection to the outside. FIG. 3 is a diagram for explaining a process of adjusting the arrangement length of the flat cable 36.

  The flat cable 36 is obtained by integrating both surfaces of a large number of leads arranged in parallel by being sandwiched by a tape-like insulator, and is flexible and can be bent freely.

  As shown in FIG. 3, the flat cable 36 is attached in a state protruding from the end of the backlight panel 20 by a predetermined length l3. Here, it is difficult to reduce the dimensional error of the flat cable 36. For example, the flat cable 36 is used after being cut from a length of several meters to a necessary length, but it is difficult to reduce a dimensional error at that time. In addition, it is difficult to reduce the dimensional error when mounted on the substrate. Therefore, even if there is a large error in the length of the flat cable 36, the flat cable 36 is attached by the following method in order to absorb the error.

  First, the flat cable 36 is cut from the long state in advance so as to be longer than the length l4 required in the arrangement direction. Specifically, there may be an error as long as it is equal to or longer than the length l4 plus the length that allows the flat cable 36 to be folded back.

  Then, as shown by a two-dot chain line in FIG. 3, the end of the flat cable 36 is soldered in the direction opposite to the arrangement direction. Specifically, the end leads are exposed and soldered.

  Next, the flat cable 36 is folded back in the arrangement direction. Thus, the tip of the flat cable 36 protrudes from the end of the backlight panel 20. If the bending position is adjusted, the protruding length can be reduced to l3.

  According to the above process, even if there is an error in the length of the flat cable 36, the error can be absorbed by adjusting the bending position. Since this adjustment work is simpler than adjusting the dimensions accurately, the workability can be improved. Conventionally, when the flat cable length error is large, the flat cable is slackened by the length longer than the predetermined length. However, the error can be absorbed by bending, and as a result, the slack of the flat cable 36 is eliminated. Can do. If there is no slack, there is no useless space and the liquid crystal display device can be made thinner. The direction in which the flat cable 36 is bent is not limited to the direction shown in FIG. For example, the flat cable 36 may be bent so that the direction before bending and the direction after bending intersect each other.

  The present invention is not limited to the above embodiment, and various modifications can be made. FIG. 4A and FIG. 4B are schematic views showing a modification of the embodiment.

  For example, as shown in FIG. 4A, a convex portion 58 formed by the light emitting portion 56 of the backlight panel 54 is accommodated in the space below the protruding portion 52a of the substrate 52 on the upper side of the liquid crystal panel 50. Good.

  Alternatively, as shown in FIG. 4B, the backlight panel 66 may be attached so that the light emitting part 64 is disposed under the protrusion 62 a of the substrate 62 on the lower side of the liquid crystal panel 60.

It is a sectional side view of the liquid crystal display device which concerns on embodiment. 1 is an exploded perspective view schematically showing a liquid crystal display device according to an embodiment of the present invention. It is a figure explaining the process of adjusting the arrangement | positioning length of a flat cable. It is the schematic which shows the modification of embodiment.

Explanation of symbols

10 liquid crystal panel, 12 substrate, 12a protrusion, 12b electrode, 14 substrate,
14a protrusion part, 14b electrode, 20 backlight panel, 22 light emitting part,
22a light emitting element (point light source), 24 light guide plate part, 24a reflector, 26 support part,
26a protrusion (positioning part), 28 effective light emitting part, 29 transient region,
30 circuit board, 36 flat cable (connection member)

Claims (6)

An edge-type backlight in which a liquid crystal panel in which liquid crystal is sandwiched between a pair of substrates, a pair of electrodes provided on opposite surfaces of the pair of substrates, and at least one light source disposed at an end portion as a surface light source A panel, and
The pair of substrates are arranged offset from each other to form a protrusion, and one of the electrodes is exposed on the protrusion,
The light source of the said backlight panel is a liquid crystal display device arrange | positioned in the area | region which faces the said protrusion part. The liquid crystal display device according to claim 1.
The backlight panel has a plurality of point light sources, an effective light emitting unit that is uniformly converted into a surface light source, and a transition region from the point light source to the effective light emitting unit,
At least a part of the transition region and the point light source are arranged in a region facing the protruding portion. A light source disposed at the end, and a light guide plate that guides light from the light source and emits the light in one surface direction to form a surface light source,
The other surface of the light guide plate is processed to reflect the light from the light source in the direction of the one surface, and is integrated with a region other than the effective light-emitting portion that uniformly converts to a surface light source. An edge-type backlight panel on which a support is formed. The backlight panel according to claim 3.
The said support part is a backlight panel which has a positioning part with another member. The backlight panel according to claim 3 or claim 4,
A liquid crystal display device in which a liquid crystal panel is attached to the one surface and a circuit board is attached to the other surface. In the manufacturing method of the liquid crystal display device,
Cutting a long cable for electrical connection longer than necessary to obtain a connecting member;
Electrically connecting the end portion to the circuit board in a direction different from the predetermined arrangement direction;
Bending the connection member and directing the connection member in the predetermined arrangement direction;
Adjusting the bending position of the connecting member and adjusting the arrangement length of the connecting member;
A method for manufacturing a liquid crystal display device comprising:

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