JP2008134499A - Liquid crystal module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent disconnection in a flexible printed circuit board inside a case by an inexpensive method, the disconnection caused by rubbing with the end part of the case which is made by sheet metal working, in a liquid crystal display device having a box-shape case with one side open formed by the sheet metal working and having a low sidewall, and a flexible printed circuit board placed to be in contact with the inner face of the sidewall of the case. <P>SOLUTION: A liquid crystal module 1 includes: a box-shape upper case 4 formed by the sheet metal working, having one end open and having a sidewall; a lower case 39, and a flexible printed circuit board 25 extended to the outside of the device through a space between the upper case 4 and the lower case 39 and electrically connected to other equipment. In this liquid crystal module 1, a projection 4b protruding inward is formed by drawing on the sidewall of the upper case 4; and by making the projection 4b be brought into contact with the flexible printed circuit board 25, the flexible printed circuit board 25 is parted from the sidewall end part of the upper case 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal module in which a flexible printed circuit board extends outside a case.

  As a display device, a liquid crystal module is characterized by light weight, thinness, and low power consumption, and is used in many electronic devices.

  A normal liquid crystal module is a liquid crystal panel with a flexible printed circuit board, a support frame, an optical sheet (diffusion sheet, lens sheet, polarizing sheet), a light guide plate with a light source on its side, and a reflector. (See Patent Document 1). In order to make the liquid crystal module thin, the upper and lower cases are generally made of sheet metal. And the flexible printed circuit board of a liquid crystal panel is extended out of a case in order to electrically connect with the electronic device in which a liquid crystal module is incorporated. When the light source is an LED, the flexible printed circuit board of the LED also extends out of the case in order to be electrically connected to an electronic device in which the liquid crystal module is incorporated. There are various methods for taking out these flexible printed boards out of the case. As one of the inexpensive and easy methods, there is a method of going out of the liquid crystal module from between the side wall of the upper case and the side wall of the lower case. The extended flexible printed circuit board is temporarily fixed to the bottom surface of the module with double-sided tape or the like, or connected to a connector exposed on the bottom surface of the module.

Then, the liquid crystal module is packed, unpacked in the assembly line of the electronic device, and incorporated into the electronic device.
JP 2006-128036 A Japanese Patent Publication No. 5-073489

  When the case is manufactured by sheet metal processing, an R-shaped shear drop is generated at one end of the shear surface, and an edge burr (burr) is generated at the other end. For this reason, if the flexible printed circuit board is extended along the return side of the side wall of the upper case, the flexible printed circuit board may be disconnected at the time of assembling, transporting, or assembling the electronic apparatus.

  As a method to reduce the disconnection of the flexible printed circuit board due to burr, it is possible to determine the direction of the outer shape of the mold so that the burr is on the outside. However, considering the prevention of hand injury, the burr direction must be inside. .

  Thus, since the burr direction must be inside, a method of adding a sheet between the inner surface of the case and the flexible printed circuit board has been considered. However, this method has a problem of increasing the number of parts and mounting work.

Therefore, it has been considered that the case is subjected to hemming (see Patent Document 2). The hemming process is to bend and fold the end portion by 180 degrees. FIG. 5 is a diagram showing hemming. In the state before the hemming process, the burr direction of the outer shape is the inner surface direction of the liquid crystal module. The hemming process is bent to a position of 90 degrees in the first process and 150 in the second process.
It is bent to a position of about degrees, and is bent to a position of 180 degrees in the third step. Therefore, the case subjected to hemming does not damage the flexible printed circuit board by burr. However, the hemming process cannot be performed together with other drilling processes or bending processes, and three steps must be added, resulting in a problem that the processing cost increases.

In order to solve the above-mentioned problems, the invention of the liquid crystal module according to claim 1 of the present application includes a box-shaped upper case formed by sheet metal processing, one of which is open and has a side wall, a lower case, and the upper case And a flexible printed circuit board extending between the lower case and extending out of the apparatus and electrically connected to other devices,
A convex portion protruding to the inner surface side is formed by drawing on the side wall of the upper case, and the convex portion is brought into contact with the flexible printed circuit board to separate the side wall end of the upper case from the flexible printed circuit board. It is characterized by.

  The invention of the liquid crystal module according to claim 2 of the present application is characterized in that the burr direction of the side wall end portion of the upper case is an inner surface direction, and the height of the convex portion is higher than the height of the burr. To do.

  The invention of the liquid crystal module according to claim 3 of the present application is characterized in that the length of the convex portion exceeds the width of the flexible printed circuit board.

  The invention of a liquid crystal module according to claim 4 of the present application is characterized in that the convex portion extends beyond the width of the flexible printed board to the vicinity of both end portions of the side wall.

  According to the first aspect of the present invention, the convex portion that protrudes toward the inner surface and contacts the flexible printed circuit board is drawn on the side wall of the case so that the side wall end of the upper case and the flexible printed circuit board are separated from each other. Form with. Thereby, there exists an effect that a flexible printed circuit board prevents the disconnection by the sharp burr of the side wall edge part with an inexpensive structure.

  According to claim 2 of the present invention, the burr direction of the side wall end portion of the upper case is the inner surface direction, and the height of the convex portion is higher than the height of the burr. Thereby, the disconnection prevention effect can be enhanced.

  According to claim 3 of the present invention, the length of the convex portion extends beyond the width of the flexible printed circuit board. Thereby, it is possible to supply the upper case liquid crystal module which also serves to reinforce the side wall of the excess portion, and the flexible printed board is hard to be disconnected and hardly deformed.

  According to claim 4 of the present invention, the convex portion extends to the vicinity of both end portions of the side wall. Thereby, the long range of a side wall can be reinforced.

  Hereinafter, the best embodiment of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a liquid crystal display device for embodying the technical idea of the present invention, and is not intended to identify the present invention as this liquid crystal module, and claims Other embodiments that fall within the scope are equally applicable.

The liquid crystal module 1 of the present invention is a display module incorporated in an electronic device. FIG. 1 is a plan view of the top case seen through with the side wall of the upper case left, FIG. 2 is a plan view seen through the upper case and the liquid crystal panel, and FIG. 3 is a cross-sectional view taken along line AA ′ of FIG. .

  The liquid crystal module 1 is configured such that a backlight unit 3 is disposed on the back surface of the liquid crystal panel 2.

  As shown in FIGS. 1, 2, and 3, the backlight unit 3 includes a diffusion sheet 32, an X-direction lens sheet 33, a Y-direction lens sheet 34, between a middle case 31 and a lower case 39, which are sheet metal processed materials. A light guide plate 37 and a reflection plate 38 of PMMA (polymethyl methacrylate) having a diffusion sheet 35 and a fluorescent discharge tube 36 on the side surfaces are laminated.

  The middle case 31 is a stainless steel material having a sheet thickness of 0.2 mm, is formed by sheet metal processing, and has a box shape having a large square hole 31a on the upper side, all open on the lower side. The side walls are short and are formed by extrusion. The lower case 39 is a stainless steel material having a plate thickness of 0.2 mm, and is formed by sheet metal processing and has a box shape with the upper part opened. The side walls are short and are formed by extrusion. The lower case 39 is fitted into the middle case 31 so that the side wall of the lower case 39 covers the side wall of the middle case 31. The middle case 31 and the lower case 39 are engaged with each other by engaging the square protrusions 31 a provided on the side wall of the lower case 39 with the square holes 31 b provided on the side wall of the middle case 31.

  As shown in FIG. 2, the fluorescent discharge tube 36 is a fluorescent lamp using a straight tube type cold cathode arc extending in the longitudinal direction of the light guide plate 37. Power supply leads 361 and 362 are connected to both terminals of the fluorescent discharge tube 36 and extend outside the liquid crystal display unit 1. The fluorescent discharge tube 36 is held by fitting both electrode portions into holders 40 and 41.

  Light emitted from the fluorescent discharge tube 36 is transmitted through the light guide plate 37, the reflection plate 38, the light guide plate 37, the diffusion sheet 35, the Y-direction lens sheet 34, the X-direction lens sheet 33, the diffusion sheet 32, and the rectangular holes 31 a of the inner case 31. The light is irradiated to the back surface of the liquid crystal panel 2 via the line.

  The liquid crystal panel 2 has three source driver ICs 21, 22, 23, a gate driver IC 24, and a flexible printed board 25. The flexible printed circuit board 25 has leads (not shown) for transmitting control signals, and the source driver ICs 21, 22, 23 and the gate driver IC 24 are display elements (not shown) of the liquid crystal panel 2 based on the control signals. Drive.

  The liquid crystal panel 2 is disposed between the upper case 4 and the middle case 31. The upper case 4 is a stainless steel material having a plate thickness of 0.2 mm, is formed by sheet metal processing, and has a box shape having a large square hole 4a open at the bottom and opened upward. The side walls are short and are formed by extrusion.

  Although not shown, the two short side walls (the side walls in the left-right direction in FIG. 1) of the upper case 4 and the middle case 31 and one of the two long side walls (the side walls in the upper direction in FIG. The case 39 is fitted with the same square hole and projection as the case 39 is fitted. By forming protrusions 31c and 31d on the other long side wall of the middle case 31 (the side wall in the downward direction in FIG. 1), a flexible space is provided between the other long side wall of the upper case 4 and the other long side wall of the middle case 31. A gap through which the printed circuit board 25 passes is provided. The flexible printed circuit board 25 passes between the side wall of the upper case 4 and the side wall of the middle case 31 and is temporarily fixed to the bottom surface of the lower case 39 with the double-sided tape 5. This temporary fixing is peeled off when the liquid crystal module 1 is incorporated into an electronic device.

  Next, the direction of burr and the direction of burr due to shearing in sheet metal processing will be described. As shown in FIG. 3, the end portion (that is, the outer shape) of the side wall of the middle case 31 and the square hole 31 b are on the outside and the inside is burred. For this reason, there is little possibility that the flexible printed circuit board 25 is damaged by the side wall of the middle case 31.

  The end portion (that is, the outer shape) of the side wall of the upper case 4 is the outer side, and the inner side is burred. And the convex part 4b which protrudes in the flexible printed circuit board 25 side is formed by extrusion on the inner surface of the side wall with which the flexible printed circuit board 25 contacts. The height of the convex portion 4b (h2 in FIG. 3) is at least higher than the height of the burr of the upper case 4 (h1 in FIG. 3). For example, the height of the burr is 0.02 mm. The height of the part is 0.1 mm. The shape of the top of the convex portion 4b is flat so that no concentrated stress is applied to the flexible printed circuit board 25. As shown in FIG. 4, the length of the convex portion 4b extends beyond the width of the flexible printed board 25 to the vicinity of both end portions of the side wall (in FIG. 4, the convex portion 4b abuts against the protruding portions 31c and 31d. It extends to the extent that it does not.) It also serves as reinforcement (prevention of deformation) of the side wall of the excess part. Thus, the convex part 4b is also what is called a reinforcement bead. The convex portion 4b separates the flexible printed circuit board 25 from the burr, thereby reducing damage to the flexible printed circuit board 25.

  The convex portion 4b can be formed in one process, and the mold cost and component unit price can be reduced compared with the conventional hemming process that requires three processes.

  In addition, although the flexible printed circuit board of the above-mentioned Example was a flexible printed circuit board of a liquid crystal panel, the flexible printed circuit board of this invention is not limited to this, It applies to the flexible printed circuit board for LED used as a light source You can also.

The top surface of the upper case of the present invention is seen through. It is the top view which saw through the upper case and the liquid crystal panel. It is A-A 'sectional drawing of FIG. It is a figure which shows the side surface of an upper case. It is a figure which shows a hemming process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal module 2 Liquid crystal panel 3 Backlight unit 4 Upper case 5 Double-sided tape 25 Flexible printed circuit board 31 Medium case 32 Diffusion sheet 33 Lens sheet 34 Lens sheet 35 Diffusion sheet 36 Fluorescent discharge tube 37 Light guide plate 38 Reflection plate 39 Lower case 4b Convex Part

Claims (4)

A box-shaped upper case formed by sheet metal processing, one of which is open and has a side wall, a lower case, and a space between the upper case and the lower case that extends out of the apparatus and is electrically connected to other devices. In a liquid crystal module having a flexible printed circuit board connected to
A convex portion protruding to the inner surface side is formed by drawing on the side wall of the upper case, and the convex portion abuts against the flexible printed circuit board to separate the side edge of the upper case from the flexible printed circuit board. LCD module characterized by The liquid crystal module according to claim 1, wherein a burr direction of a side wall end portion of the upper case is an inner surface direction, and a height of the convex portion is higher than a height of the burr. The liquid crystal module according to claim 1, wherein a length of the convex portion exceeds a width of the flexible printed circuit board. The liquid crystal module according to claim 1, wherein the convex portion extends beyond the width of the flexible printed board to the vicinity of both end portions of the side wall.

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