JP4548124B2 - LCD module - Google Patents

Description

The present invention relates to a liquid crystal module, and in particular, has a feature in a light source lamp reflector fixing structure formed by a light guide plate of a backlight and a reflection sheet, and can easily and stably attach a reflection sheet when forming the reflector. The present invention relates to such a liquid crystal module.

In recent years, liquid crystal display devices have been widely used as display devices such as computers, personal digital assistants (PDAs), in-vehicle navigation devices, mobile phones, and television devices because of their low power consumption, thinness, and light weight. It is coming.

The liquid crystal module is usually a liquid crystal panel, an optical sheet such as a diffusion plate or a prism sheet, a light guide plate, a reflection sheet, a resin frame surrounding these, a lamp set close to the side end surface of the light guide plate, and a back side that houses them. And a front frame that covers the periphery of the front surface of the liquid crystal panel and the side surface of the assembly. The liquid crystal panel is mounted with a gate driver IC and a source driver IC by a TAB (Tape Automated Bonding) method, and is driven by a printed circuit board on which a control circuit connected thereto is mounted.

Among these liquid crystal display devices, in-vehicle navigation devices and PDA (Personal Digital
A small liquid crystal display device such as an assistant or a portable information terminal has been devised in various ways to increase the effective display area of the liquid crystal panel and narrow the frame of the front frame as much as possible.

And, for example, in-vehicle navigation devices are limited in the limited space under the dashboard of the car, so the effective display area of the liquid crystal panel is enlarged and the frame portion of the front frame is reduced. There are difficulties. Therefore, the light source of the backlight is not a configuration in which a lamp set in which a lamp is mounted on a metal U-shaped reflector is inserted along the side end surface of the light guide plate as in a large liquid crystal display device. A simple structure is often employed in which the sheet is extended not only to the bottom surface of the light guide plate but also to the side to form a raised portion, and the upper portion of the raised portion is attached to the end surface of the light guide plate as a reflector.

That is, in the liquid crystal module 100 as shown in FIG. 8 disclosed in the conventional patent document 1, the liquid crystal panel 120, the backlight 110 that generates illumination light for the liquid crystal panel,
An optical sheet 130 that is disposed between the backlight 110 and the liquid crystal panel 120 and supplies illumination light from the backlight 110 to the liquid crystal panel 120 and a resin frame 114 that integrally stores them are provided. The backlight 110 has a substantially rectangular light guide plate 11 having an illumination surface on the front surface.
1, a tubular light source 112 extending along the three sides of the light guide plate 111, a reflection sheet 143 that guides light from the light source 112 to the illumination surface 111 a side of the light guide plate 111, and the reflection sheet 143 and the light guide plate 111. A back case 114b that is housed and supported integrally. Reflective sheet 143
Is a reflection sheet 143b on the back side disposed on the back side of the light guide plate 111, and a light source 112 extending from the reflection sheet 143b and extending in three directions: the back surface of the light source 112, the side surface raised from the light guide plate 111, and the front surface. The reflector 143a surrounding the periphery of the reflector is integrally formed as a reflector integrated type.
Japanese Patent Laying-Open No. 2004-111153 (FIG. 8, paragraphs [0004] to [0009])

In forming the reflector 143a, the operation of attaching the end portion 143c of the reflection sheet to the end portion of the light guide plate 111 with the double-sided tape 145 or the like is performed manually, but the reflection sheet 143b on the back side is the light guide plate 111. Since it is not directly fixed to the back surface of the lens, it is likely to be displaced and unstable.

In addition, it is difficult to perform accurate alignment during the pasting, and there is a high risk of misalignment. If a product with a shifted position is used, light unevenness occurs, so that it is necessary to repeat the mounting operation, and there is a problem that the workability is poor and the mounting is troublesome.

Therefore, there is a demand for a liquid crystal module that increases the efficiency of the bonding operation between the reflection sheet 143 and the light guide plate 111 and suppresses the occurrence of light unevenness.

In addition, in the conventional backlight, a relative positional shift occurs between the light guide plate and the reflector due to a change in ambient temperature and a temperature change caused by turning on / off the backlight light source. Is also sought.

As a result of various studies to solve the above problems, the inventor of the present application pays attention to the rear surface end portion of the light guide plate that does not affect the effective light emitting area in the liquid crystal module, and forms a boss there. It has been found that by locking the reflection sheet with a boss, the position of the reflection sheet can be stabilized and the attachment of the reflector to the light guide plate can be facilitated, and the present invention has been completed.

That is, an object of the present invention is to provide a liquid crystal module capable of easily and stably fixing a reflection sheet to a light guide plate.

In addition, the present invention provides a displacement between the light guide plate and the reflector due to a positional shift when the reflective sheet is attached to the light guide plate in the backlight, or a change in ambient temperature, or a temperature change caused by turning on or off the backlight light source. An object of the present invention is to provide a liquid crystal module having a relative positional shift as small as possible.

The object of the present invention can be achieved by the following means. That is, the invention of a liquid crystal module according to the present application, the reflective sheet and the light source and the light guide plate accommodated in the back casing, the liquid crystal panel is disposed on the surface side of the light guide plate, arranged on the rear surface side of the light guide plate wherein The reflection sheet has a reflector structure that covers a light source located on a side surface of the light guide plate, and an end portion of the reflector is fixed to an end portion of the light guide plate and provided on the back surface of the light guide plate. In the liquid crystal module in which the formed boss is positioned through the through hole provided in the reflection sheet, a step for supporting the flat portion is provided on the bottom surface of the back case, and the step is provided between the flat portion and the reflection sheet. A support member is disposed in the boss, and the boss of the light guide plate passed through the reflection sheet is inserted into a boss insertion hole provided in the support member. .

Further, the invention of the liquid crystal module according to the present application is characterized in that the through holes are provided at four corners of the reflection sheet, and the bosses of the light guide plate are positioned at the four corners.
In the liquid crystal module according to the present invention, the flat part of the back case is provided with a screw hole, and the support member is provided with a recess corresponding to the screw hole so that fixing by screwing is possible. It is made possible.

The invention of the liquid crystal module according to the present application is characterized in that, in the liquid crystal module, the boss is provided integrally with the light guide plate near the end surface of the back surface of the light guide plate.

In the liquid crystal module according to the present invention, in the above liquid crystal module, the light guide plate includes a flange between the liquid crystal panel and the light source, and the reflector structure has a rising edge of the reflection sheet on an end surface of the flange. It is formed by sticking the edge part of a part.

Further, the invention of the liquid crystal module according to the present application is such that, in the liquid crystal module, the screw hole is provided at a position corresponding to the corner of the back case, and the mounting portion provided with the screw hole is provided on the back case. in the corner near, and drawing process at the inner portion of the back casing, and characterized in that it is shaped to omit the outer peripheral portion of the back casing

By providing the above configuration, the present invention has the following excellent effects. In other words, according to the invention, since the boss provided on the back surface of the light guide plate is passed through the through hole provided in the reflection sheet, the reflection sheet does not shift and is attached to the end of the light guide plate. It can be done easily with good quality.

According to the above invention, the reflection sheet can be easily attached to the end of the light guide plate with good workability, and the boss on the back surface of the light guide plate is inserted into the boss receiving hole of the back case. Since it is possible to suppress the occurrence of light unevenness due to the shift of the reflection sheet during use, a liquid crystal module useful as a small display device for movement such as in-vehicle navigation can be provided.

Further, according to the above invention, the reflection sheet can be fixed without affecting the effective light emitting area of the light guide plate by providing the boss integrally with the light guide plate near the end surface of the back surface of the light guide plate.

Moreover, according to said invention, since the edge part of a reflection sheet exists in the position away from the display area, the influence by having a reflection sheet edge part in the vicinity of a display area can be prevented effectively.

Further, according to the above invention, the boss locking means is provided on the support member that also serves as the attachment of the liquid crystal module, so that the reflection sheet can be easily held and the fixing work can be facilitated.

In addition, according to the above invention, since the shape of the drawn portion of the back case is simple, drawing is easy, and mounting and fixing of the resin support member is also easy, so that the mounting portion can be easily formed. Can be formed.

Moreover, according to said invention, the effective area, such as arrange | positioning a circuit board, can be ensured more widely in the back side of a liquid crystal module.

Hereinafter, the best mode for carrying out the invention of the liquid crystal module according to the present invention will be described in detail with reference to the embodiments and the accompanying drawings. However, the examples shown below exemplify liquid crystal modules for embodying the technical idea of the present invention, and are not intended to specify the present invention to these examples. The present invention can be equally applied to various modifications without departing from the technical idea shown in the claims.

FIG. 1 is an exploded perspective view of an embodiment of a liquid crystal module according to the present invention. FIG. 2 is a back plan view seen from the back case in one embodiment of the liquid crystal module according to the present invention. FIG.
FIG. 3 is an enlarged plan view of a part of FIG. 2.

In the present embodiment, a display device of an in-vehicle navigation device will be described as an example of a small liquid crystal display device used while moving. The liquid crystal module 10 of this in-vehicle navigation device has the following configuration if it is described in detail with reference to FIG. 1, which is an exploded perspective view of the present invention as viewed obliquely from below.

That is, there is a liquid crystal panel 11 in which a cell substrate and its counter substrate are bonded together with a sealing material, and liquid crystal is sealed between the two substrates. Further, a gate driver I for driving the liquid crystal panel 11 provided directly on the edge of the cell substrate of the liquid crystal panel 11 by the COG method.
A drive circuit (not shown) composed of C and a source driver IC, and a control circuit board (not shown) on which a controller and other electronic components connected to each drive IC of the liquid crystal panel 11 and controlling these drive ICs are mounted. Flexible printed wiring (FPC) board 1 for connection to (not shown)
2a and 12b. In addition, a plurality of optical sheets 15 a to 15 arranged on the back surface of the liquid crystal panel 11.
There is 15c. There is a rectangular light guide plate 17 made of acrylic resin. There is also a white reflective sheet 18 disposed on the back of the light guide plate. Further, there is a back case 19 that houses the optical sheets 15a to 15c, the light guide plate 17, and the reflection sheet 18. There is a frame-shaped resin frame 14 that supports the liquid crystal panel 11 on the upper side and fits with the back case 19 on the lower side. LCD panel 1
There is a frame-shaped front frame 22 that covers the liquid crystal panel 11 and the like from the front surface of 1.

Around the periphery of the light guide plate 17, a flange 23 positioned between the liquid crystal panel 11 and the tubular lamp 21 is led out from the light guide plate 17 along the side end surface thereof. The tubular lamp 21 is disposed in a lamp housing portion 24 formed in a gap in the resin frame 14 by the flange 23 of the light guide plate 17 and the reflection sheet 18. In this embodiment, the collar 23 is not only the tubular lamp 21 but also the tubular lamp 21.
It exists also in the position of the cable 27 extended from both ends.

The tubular lamp 21 is arranged so that the emission surface of the tubular lamp 21 is parallel to the side edge (side end surface) that is the light incident surface of the light guide plate 17 made of transparent acrylic resin or the like. FPC board 12a,
12b is guided to the back surface by turning the side surface of the resin frame 14, and is connected to a control circuit board (not shown) attached to the back surface of the back case 19. The control circuit board attached to the back surface of the back case 19 is covered with a metal cover via an insulating sheet (not shown).

In the present embodiment, as will be described in detail later, the mounting portions 19a for fixing the liquid crystal module 10 provided at each corner of the back case 19 constituting the liquid crystal module 10 to the car are close to the corners of the back case 19. The mounting bracket for fixing the liquid crystal module to the car (not shown) is provided by drawing the inner part of the back case by omitting the restriction on the outer periphery of the back case.
Is attached to the back case 19 by being screwed into a screw hole 19b formed in the attachment portion 19a.

That is, as shown in FIG. 2, the mounting portion 19 a for fixing the liquid crystal module provided on the metal back case 19 has a printed circuit board (not shown) on which various ICs and components are mounted on the back case 19. The rear case 19 is provided closest to the corner so as not to obstruct the attachment.

And in order to provide at the corner of each corner of the back case 19 as much as possible, the shape of the mounting portion 19a is:
The drawing process is omitted in the substantially semicircular portion 19d that overlaps with the outer peripheral portion of the back case 19 instead of the circular dish shape that is well known from the past, and only the substantially semicircular portion located inside the back case is drawn. It has a shape provided. The mounting portion 19a has a screw hole 19b in a flat surface portion 19e partitioned into a substantially semicircular step 19c and an outer periphery 19d of a back case without a substantially semicircular side wall. The outer peripheral portion of the screw hole 19b hangs down in a predetermined length in the direction in which the liquid crystal panel 11 is provided, and a screw is cut inside the suspended cylindrical portion (not shown). The mounting bracket is attached to the cylindrical portion by screwing the mounting bracket for fixing the liquid crystal module.

The flexible printed circuit boards 12 a and 12 b are guided to the back surface by turning the side surface of the resin frame 14 and connected to a control circuit board (not shown) attached to the back surface of the back case 19. The control circuit board is further covered with a metal cover (not shown) via an insulating sheet. Reference numeral 26 denotes a connector connected to the lamp cable 27.

That is, as shown in FIG. 3, which is an enlarged plan view of a portion surrounded by a circle in FIG. 2, the liquid crystal module is attached to the metal back case 19 and is divided by obtuse steps 19c at the four corners of the back case 19. A mounting portion 19a is provided. No step of the diaphragm is provided in the portion 19d along the edge of the back case. A plane portion 19 partitioned into a step 19c and an outer periphery 19d of the back case
A screw hole 19b threaded into e is provided. In order to form the mounting portion 19a as close to each corner as possible, the flat portion 19 is supported only by the step 19c because the mounting portion 19a has a shape different from the well-known circular dish shape as described above. , Outer case 1
There is no side wall connected to the flat surface portion 19e in the 9d portion. Therefore, even if you turn the screw in the screw hole 19b, the flat part 19e will be crushed. Therefore, in this embodiment,
A resin support member 25 is disposed at each corner inside the back case and supports the flat portion 19e. The flat portion 19e is supported on the outer periphery 19d of the back case, instead of arranging the support member 25 as in this embodiment, for example, the side wall of the front frame 22 may be used.

The plane portion 19e is provided with a hole 19f as a locking means for the support member 25. In addition, you may provide a thing like a cut and raised instead of this hole 19f.

Next, the configuration of the liquid crystal backlight portion will be described with reference to FIGS. 4 is an exploded perspective view illustrating the configuration of the backlight portion of the liquid crystal module, and FIG. 5 is an exploded perspective view of FIG. 4 viewed from the reverse direction, both of which are the light guide plate 17 viewed from the front. The arrangement of the tubular lamp 21, the reflection sheet 18, the support member 25 and the back case 19 is shown. And the light guide plate 17
A tubular lamp 21 such as a U-shaped cold cathode tube is arranged in the periphery of the light source to constitute a backlight together with the reflection sheet 18, and fitted into the frame body 14 (see FIG. 1) together with the plurality of optical sheets 15a to 15c. It is accommodated in the back case 19.

The light guide plate 17 is made of a transparent resin plate or a transparent glass plate having a high light transmittance such as acrylic resin, polycarbonate, AS, and PET, and has a substantially rectangular parallelepiped shape having an effective light emitting area slightly larger than the effective display area of the liquid crystal panel 11. A portion (23) formed in the shape of a bowl is provided around the plate, and a storage portion 24 such as a tubular lamp 21 is formed. Light guide plate 17
For example, a U-shaped tubular lamp 21 extending over three sides is disposed under the flange 23, and a cable 27 connected to the tubular lamp 21 is wired on the remaining side. The front surface of the light guide plate 17 is a light emitting surface, and is provided with a diffusion plate made of translucent polycarbonate or the like having a high light transmittance, optical sheets 15a to 15c made of a polarizing plate, a lens sheet, and the like, and uniformly distributes light from the lamp light source. To spread. Further, the back surface of the light guide plate 17 is subjected to dot-like processing, scratches, or embossing by screen printing so as to diffusely reflect light.

Further, on the back side of the light guide plate 17, a white polyester or a reflection sheet 18 obtained by applying a silver vapor deposition film to a polyester film is disposed. The periphery of the reflection sheet 18 extends from the back surface of the light guide plate 17 and is bent to form a raised portion 18a. The upright portion 18 a wraps the tubular lamp 21, and its end is attached to the end face of the flange 23 of the light guide plate 17 with a double-sided tape or the like to constitute a reflector of the tubular lamp 21.

As is apparent from the description of FIGS. 4 and 5, the support member 25 is attached to each mounting portion 19.
It is a bottomed spacer having a cylindrical recess 25a for receiving a screw hole 19b, which is resin-molded into a shape corresponding to a. Of these, the cylindrical recess 25a has a large diameter near the opening,
The back part has a two-stage structure with a smaller diameter than the part close to the opening. A portion close to the opening is press-fitted into the cylindrical portion of the screw hole 19b, so that the support member 25 is attached to the back case 1.
9 is fixed. The screw hole 19b of the support member 25 is bottomed in order to prevent dust from entering from the screw hole 19b of the mounting portion. The support member 25 is formed with a locking means 25b such as a protrusion or hole for positioning corresponding to the locking means 19f provided on the mounting portion 19a of the back case 19, and the screw hole and the locking means The liquid crystal module 10 is assembled by fitting the back case 19 into the resin frame 14 in which the backlight is accommodated after being fitted and positioned. With this configuration, the support member 25 is inserted between the attachment portion 19 a of the back case 19 and the reflection sheet 18.

FIG. 6 is a perspective view of the assembled state of the light guide plate 17 and the reflection sheet 18 as seen from the back surface of the reflection sheet 18 in order to show how the support member 25 is in relation to the reflection sheet 18.
Boss 17 for alignment with reflection sheet 18 provided integrally with light guide plate 17 on the lower surface of light guide plate 17
a penetrates the hole 18 b provided in the reflection sheet, protrudes from the lower surface of the reflection sheet 18, and is inserted into the boss insertion hole 25 c provided on the bottom surface of the support member 25. Therefore, the reflection sheet 18
Is positioned by the boss 17a of the light guide plate and the support member 25 at the four corners of the bottom surface.
Thereby, the reflective sheet 18 and the light guide plate 17 are accurately positioned, and a backlight without misalignment is obtained in which the light guide plate 17, the tubular lamp 21 serving as the light source, and the reflective sheet 18 are integrated. The boss 17a is provided near the end surface of the back surface of the light guide plate, thereby allowing the light guide plate 1 to
The reflective sheet 18 can be fixed without affecting the effective light emitting area 7.

FIG. 7 is a cross-sectional view taken along the line AA in FIG. The resin frame 14 supports the liquid crystal panel 11 on the upper side of the frame, and a plurality of optical sheets 15a to 15c, a light guide plate 17, and a reflection sheet 18 are sequentially fitted on the lower side and stored in the back case 19. ing. The front frame 22 is fitted from the front of these components, and the liquid crystal module 10 is assembled. As described above, the support member 25 is inserted between the reflection sheet 18 and the mounting portion 19a of the back case 19, and the boss 17a of the light guide plate 17 penetrates the reflection sheet 18 to insert the boss of the support member 25. The reflective sheet 18 is positioned by being inserted into the hole 25c. Further, the locking means 25 b of the support member 25 is fitted in the hole 19 f of the back case 19. A tubular lamp 21 serving as a backlight light source is disposed under the flange 23 of the light guide plate 17 so as to face the end surface of the light guide plate, and the end portion of the upright portion 18a of the reflection sheet 18 covering the back and side surfaces of the light guide plate 17 is the light guide plate. Attached to the end face of the collar 23 with a double-sided tape is fixed.

The reflection sheet 18 is formed on the end surface of the flange 23 that partitions the storage portion 24 of the tubular lamp 21.
The operation of attaching the end face is usually difficult because the positions of the light guide plate 17 and the reflection sheet 18 are shifted. However, in this embodiment, since the reflection sheet 18 is positioned by the boss 17a, the fixing operation can be easily performed, and the occurrence of light unevenness due to the deviation of the reflection sheet can also be suppressed.

Further, the boss 17 a not only positions the reflecting sheet 18 but also acts to suppress the movement of the light guide plate 17 as the positioning of the light guide plate 17, and has a function of preventing the tubular lamp 21 from being damaged. In a liquid crystal module of a device exposed to large vibrations such as in-vehicle and portable devices, there is a risk that the light source tubular lamp 21 is bent and damaged due to the bending of the tubular lamp 21 due to vibration and the movement of the light guide plate 17. there were. However, the risk of breakage can be reduced by suppressing the movement of the light guide plate 17. Alternatively, ambient temperature fluctuations, lighting of the light source tubular lamp 21,
A relative positional shift between the light guide plate 17, the reflection sheet 18, and the reflector due to a temperature change caused by turning off the light can also be reduced.

In addition, irrespective of the above embodiment, the shape of the mounting portion of the light guide plate can be designed as appropriate. In the above description, the boss provided on the back surface of the light guide plate is described as engaging the support member through the through hole of the reflection sheet. However, the boss may be directly inserted into the boss receiving hole provided in the metal back case. Good.

Further, the boss provided on the light guide plate is not a rod-like protrusion but may be a protrusion having another shape, for example, a long and narrow rib, but does not affect the effective light emitting area at the corner of the light guide plate. It is preferable to form in such a position.

The above-mentioned liquid crystal module 10 is a small in-vehicle navigation device, PDA, portable D
It can be used effectively as a liquid crystal module such as a VD player. Since the liquid crystal module has a mounting portion 19a in which the side walls of the corners extending over the adjacent sides at the four corners of the back case 19 are cut out and fixed to the device mounting portion by a metal fitting attached to the back surface of the mounting portion, There is no need to install the liquid crystal module reliably and reliably. In addition, the liquid crystal module can simplify the mounting bracket and the like, is compact, has an effect of expanding the effective display area of the liquid crystal panel, and narrowing the frame.

It is a disassembled perspective view of one Example of the liquid crystal module which concerns on this invention. It is a back surface top view of the back case in one Example of the liquid crystal module which concerns on this invention. FIG. 3 is an enlarged plan view of a part of FIG. 2. It is a disassembled perspective view explaining the structure of the backlight part of a liquid crystal module. It is the disassembled perspective view which looked at FIG. 4 from the reverse direction. It is a perspective view which shows the assembly state of a light-guide plate and a reflective sheet. It is sectional drawing of the AA part of FIG. It is a partial cross section figure of the conventional liquid crystal module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Liquid crystal panel 14 Resin frame 17 Light guide plate 17a Light guide plate boss 18 Reflection sheet 18b Hole provided in the reflection sheet 19 Back case 19a Mounting part 19b Screw hole 19c Step 19d Outer periphery of back case 19e Plane part 19f Locking means 21 Tubular lamp 23 ２４ 24 Lamp housing part 25 Support member 25c Hole for boss insertion

Claims (5)

A light guide plate, a reflective sheet, and a light source are stored in the back case,
A liquid crystal panel is disposed on the surface side of the light guide plate,
The reflective sheet disposed on the back side of the light guide plate has a reflector structure that covers a light source located on a side surface of the light guide plate,
In the liquid crystal module in which an end portion of the reflector is fixed to an end portion of the light guide plate, and a boss provided on the back surface of the light guide plate is positioned through a through hole provided in the reflection sheet. ,
A step is provided on the bottom surface of the back case to support a flat portion, a support member is disposed between the flat portion and the reflective sheet, and the light guide plate passed through the reflective sheet. The liquid crystal module according to claim 1, wherein the boss is inserted into a boss insertion hole provided in the support member . The liquid crystal module according to claim 1, wherein the through holes are provided at four corners of the reflection sheet, and the bosses of the light guide plate are passed through the four corners. The flat part of the back case is provided with a screw hole, and the support member is provided with a recess corresponding to the screw hole, so that fixing by screwing is possible. The liquid crystal module according to claim 1 or 2. The light guide plate includes a ridge between the liquid crystal panel and the light source,
The reflector structure, the liquid crystal module according to claim 1 to claim 3, characterized in that it is formed by adhering the end portion of the rising portion of the reflecting sheet on the end face of the eaves. The screw holes are provided at positions corresponding to the corners of the back case, and the mounting portion provided with the screw holes is drawn at the inner portion of the back case near the corner of the back case, and the liquid crystal module according to claim 3, characterized in that there is a case omitted shape the circumference of the.

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