JP2007206125A - Lcd backlight frame, holding structure for lcd module, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LCD backlight frame which can be made thin and increase the adhesive strength of an LCD. <P>SOLUTION: On a surface coming into contact with the LCD module 1, a step is formed at a position corresponding to the boundary between a back glass 5 that the LCD 2 has and a back polarizer 6 provided on the reverse surface of the back glass 5. The top surface of an upper stage portion bordering the step is bonded to the back glass 5 with a both-sided adhesive tape 22 to hold the back glass 5. The top surface of a lower stage portion bordering the step is bonded to the back polarizer 6 with the both-sided adhesive tape to hold the back polarizer 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an LCD backlight frame, an LCD module holding structure, and an electronic apparatus having the structure.

  In recent years, the demand for mobile communication devices has increased rapidly. Among them, mobile phones for public communication have been widely used by individuals and companies due to the enhancement of communication services and the reduction in communication charges. As applications of these mobile communication devices, not only voice transmission / reception but also Internet access and use of e-mail are rapidly increasing, and there is a tendency that the area of an LCD (Liquid Crystal Display) increases due to an increase in the number of display characters. In addition, since mobile communication devices are becoming lighter, thinner, and smaller, the proportion of the LCD with respect to the overall size of the device is increasing.

  An LCD driver IC that controls driving and display of the LCD is connected to the LCD. TAB (Tape Auto Bonding), COF (Chip on film), COG (Chip on glass), etc. are generally known as this connection method. However, since the cellular phone is thin and has a small mounting area, the COG method is used. Generally adopted.

  LCDs are made by enclosing a liquid crystal material between two glass plates and pasting polarizing plates on the front and back of the combined glass. Transparent electrodes (ITO) are formed on the inner surface of each glass plate. In addition, since the electrode portion used for IC connection by the TAB, COF, and COG methods needs to expose the transparent electrode, the structure has only one glass plate.

  Further, in order to electrically connect the LCD and the substrate inside the mobile phone, in the TAB and COF systems, electrodes for connecting to the substrate inside the mobile phone are provided on the LCD. In the case of the COG method, FPC and COF are connected to the transparent electrode exposed portion of the LCD, and these FPC and COF are provided with electrodes for connecting to a substrate inside the mobile phone.

  The LCD also seals an effective display area that guarantees the specified display, an active area in the effective display area where the display is actually lit, a black mask area specific to the TFT and TFD methods, and two glasses. It is composed of a sealing area to be stopped and a crimping area used for connection with the LCD driver IC, and the dimensions of the area excluding the active area are designed to be narrow so that the display on the LCD looks as large as possible in the device.

  Also, the LCD is positioned by the LCD frame and the LCD is prevented from being damaged by mechanical stress such as drop impact or bending twist, and the LCD frame is formed in a frame shape for holding the LCD. The LCD frame may be integrated with a light guide plate for LCD illumination. In general, the polarizing plate and the LCD frame are fixed to each other by a double-sided tape as long as the LCD and the LCD frame are not affected by the active area.

  FIG. 7 is a side sectional view showing a conventional LCD holding structure.

  The LCD holding structure shown in FIG. 7 is a structure in which the LCD module 1 including the LCD 2 is held by the LCD backlight module 114.

  The LCD 2 includes a front polarizing plate 3, a front glass 4, a back glass 5, and a back polarizing plate 6.

  The LCD 2 is electrically and physically connected to the FPC 13 by heat and pressure bonding using an ACF resin 12 for FPC connection of an anisotropic conductive film. The FPC 13 is an LCD driver IC of an anisotropic conductive film. The LCD module 1 is configured by being electrically and physically connected to the LCD driver IC 11 by heat and pressure bonding using the connection ACF resin 10.

  Note that the FPC 13 is a flexible printed circuit (FPC), a chip on fpc (COF), or the like.

  On the other hand, the LCD backlight module 114 includes a light guide plate 16, a frame 115 for fixing the light guide plate 16 and positioning the LCD 2, an LED chip 117, a reflection sheet 18, a brightness enhancement film 19, and a diffusion sheet 20. And the FPC 21 on which the LED chip 117 is mounted, and the double-sided tape 122 that adheres the LCD 2 and the frame 115 to each other.

  As shown in FIG. 7, the double-sided tape 122 is attached to the back polarizing plate 6 attached to the LCD 2 in a square shape (rectangular frame shape).

  Moreover, there exists patent document 1 as a prior art document relevant to this invention.

In Patent Document 1, as shown in FIG. 1 and FIG. 2 of Patent Document 1 and the description thereof, the light guide plate includes a protruding surface and a non-projecting surface, and the liquid crystal display panel is provided with a double-sided tape. It is stuck only on the non-projecting surface of the light guide plate. The polarizing plate on the back side of the liquid crystal display panel is in contact with the surface of the light collector through the opening of the double-sided tape. That is, the double-sided tape is not bonded to the polarizing plate on the back side of the liquid crystal display panel.
JP 2002-98959 A

  However, the conventional technique shown in FIG. 7 has a problem that the module cannot be thinned unless the LED chip 117 is thinned because the double-sided tape 122 is attached to the back polarizing plate 6. Moreover, since the double-sided tape 122 is affixed on the back polarizing plate 6, there exists a problem that an adhesive area is small. In addition, since the back polarizing plate 6 is made of a soft material, sufficient adhesive strength with the double-sided tape 22 can be secured. When an external force such as a drop impact or bending twist is applied to the mobile phone, the back polarizing plate There is a problem that peeling of the plate 6 and the double-sided tape 122 occurs, the LCD 2 is violated inside the mobile phone, the LCD 2 is cracked or chipped, and the LCD 2 cannot be displayed.

  Further, in the technique of Patent Document 1, since the liquid crystal display panel is pasted only on the non-projecting surface of the light guide plate via the double-sided tape, the adhesion area is small, so that sufficient adhesive strength cannot be ensured. There's a problem.

  The present invention has been made to solve the above-described problems, and includes an LCD backlight frame, an LCD module holding structure, and an electronic device having the structure capable of being thinned and improving the adhesive strength of the LCD. The purpose is to provide.

  In order to solve the above problems, an LCD backlight module of the present invention is an LCD backlight module that holds an LCD module including an LCD, and the LCD is provided on the back surface of the back glass provided on the LCD and on the back surface of the back glass. And a holding surface for holding the LCD module in the LCD backlight module has a second step corresponding to the first step. In the holding surface, the upper step portion with the second step as a boundary is bonded to the back glass by a double-sided tape to hold the back glass, while the holding surface has the second step as a boundary. The lower stage is characterized in that it is adhered to the back polarizing plate by the double-sided tape and holds the back polarizing plate.

  In the LCD backlight module of the present invention, the LCD backlight module has an opening on a side opposite to the side on which the LCD module is disposed with respect to the holding surface, and the opening has the holding It is preferable that the reflection sheet is provided so as to be flush with the end surface opposite to the side on which the LCD module is disposed with respect to the surface.

  In the LCD backlight module of the present invention, the double-sided tape preferably has a light shielding property.

  In the LCD backlight module of the present invention, it is preferable that the double-sided tape extends to a position covering the back side of the LCD driver included in the LCD module.

  The LCD module holding structure of the present invention is characterized in that the LCD module is held by the LCD backlight module of the present invention.

  The electronic device of the present invention is characterized by having the holding structure for the LCD module of the present invention.

  The present invention is preferably a mobile phone or other portable electronic device.

  According to the present invention, for example, when the LED portion becomes thicker than the light guide plate portion due to thinning, the step caused by the thickness of the LED is absorbed by the single glass portion without the back polarizing plate of the LCD module. Thus, the thickness can be reduced. In that case, in the LED portion, the adhesive strength of the LCD can be improved by attaching the double-sided tape to the back glass or the light shielding tape without the back polarizing plate of the LCD module.

  Embodiments according to the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a front view showing an LCD backlight module according to the first embodiment, and FIG. 2 is a side sectional view showing the LCD backlight module.

  As shown in FIGS. 1 and 2, the LCD backlight module 14 according to this embodiment includes a frame for positioning the LCD 2 (not shown in FIGS. 1 and 2; see FIG. 3) and fixing the light guide plate 16. 15, light guide plate 16, LED chip 17, reflection sheet 18, brightness enhancement film 19, diffusion sheet 20, FPC 21 mounted with LED chip 17, LCD 2, and frame 15. 22.

  The double-sided tape 22 is formed in a square shape (rectangular frame shape) in a back polarizing plate 6 attached to the LCD 2 (the LCD 2 and the back polarizing plate 6 are not shown in FIGS. 1 and 2; see FIGS. 3 and 4). ) And the outer circumference of the double-sided tape 22 is set to be equal to or larger than the outer shape of the LCD 2.

  The shape of the double-sided tape 22 includes the dimensional tolerance of the back polarizing plate 6, the pasting tolerance of the back polarizing plate 6, the external dimension tolerance of the LCD 2, the mounting tolerance of the LCD 2 and the frame 15, the pasting tolerance of the frame 15 and the double-sided tape 22, The double-sided tape 22 runs on the back polarizing plate 6 in consideration of the outer tolerance of the tape 22 itself, and the back glass 5 (not shown in FIGS. 1 and 2; not shown in FIG. 1 and FIG. 2) (See FIG. 4).

  The double-sided tape 22 illuminates only the active area 8 of the LCD 2 with the light of the backlight module 14, and a double-sided tape is pasted on both sides of a light-shielding material, for example, a black PET base material, to prevent light emission unnecessary for display. The one attached is selected.

  The frame 15 is made of a material that can sufficiently withstand an external impact, and a resin or metal such as ABS or PPS is preferable.

  The brightness enhancement film 19 is commonly called a prism sheet, and is generally used in a two-layered manner as shown in FIG. 2, but depending on the type of the light guide plate 16, it may be used as a single sheet.

  The diffusion sheet 20 has a function of diffusing light and expanding the directivity of light.

  3A and 3B are diagrams showing the LCD module 1 held by the backlight module 14, in which FIG. 3A is a front view and FIG. 3B is a side view.

  As shown in FIG. 3, the LCD module 1 includes an LCD 2, an LCD driver IC connection ACF resin 10, an LCD driver IC 11, an FPC connection ACF resin 12, and an FPC 13.

  Among these, the LCD 2 includes a front polarizing plate 3, a front glass 4, a back glass 5, a back polarizing plate 6, an active area 7, a BM area 8, and a seal area 9. The active area 7 is an effective display area as an LCD.

  The FPC 13 is a flexible printed circuit (FPC), a chip on fpc (COF), or the like.

  The FPC 13 and the LCD driver IC 11 are electrically and physically connected to each other by heat-pressure bonding using the ACF resin 10 for connecting the LCD driver IC which is an anisotropic conductive film, and the LCD 2 and the FPC 13 are anisotropic. The LCD module 1 is configured by electrically and physically connecting each other by heat and pressure bonding using an ACF resin 12 for FPC connection of a conductive film.

  In a normal LCD, the front polarizing plate 3 is set as close as possible to the outer dimensions of the glass 4, and the back polarizing plate 6 is also set to be approximately the same size as the front polarizing plate 3. The back polarizing plate 6 and the front polarizing plate 3 are attached to positions facing each other with the front glass 4 and the back glass 5 interposed therebetween. That is, a portion of the back glass 5 where the back polarizing plate 6 is not attached exists in the single glass portion, and a step (first step) 24 is generated by the thickness of the back polarizing plate 6.

  In contrast, in the LCD backlight module 14, a step (second step) 26 corresponding to the step 24 of the LCD 2 is formed on the holding surface 25 that holds the LCD module 1.

  Specifically, the step 26 is caused by, for example, the LED chip 17 being thicker than the combined thickness of the light guide plate 16, the brightness enhancement film 19, and the diffusion sheet 20.

  On the holding surface 25, the upper step with the step 26 as a boundary, that is, the surface of the LED chip 17 (the right end surface in FIG. 2) is bonded to the back glass 5 by the double-sided tape 22 to hold the back glass 5.

  On the other hand, the lower surface of the holding surface 25 with the step 26 as a boundary, that is, the surface of the diffusion sheet 20 (the right end surface in FIG. 2) is adhered to the back polarizing plate 6 by the double-sided tape 22 to hold the back polarizing plate 6. To do.

  FIG. 4 is a side sectional view showing a joined state between the LCD backlight module 14 shown in FIG. 1 and the LCD module 1 shown in FIG.

  As shown in FIG. 4, the LCD backlight module 14 and the LCD module 1 are bonded to each other by a double-sided tape 22.

  In this embodiment, even when the light guide plate 16, the diffusion sheet 20, the brightness enhancement film 19, and the reflection sheet 18 are thin, and the LED chip 17 is not thin and relatively thick, the double-sided tape 22 seems to have a step. It is configured to absorb the thickness caused by the LED chip 17 projecting by fixing it to the back polarizing plate 6 at the lower part and to the back glass 5 at the higher part. Can be realized.

  Moreover, by fixing the stepped portion of the double-sided tape 22 to the back glass 5, the area where the backlight module 14 and the LCD 2 are bonded can be expanded, and the glass and double-sided tape with a smooth surface and high hardness can be used. 22 adheres, and even when a mechanical stress such as a drop impact or bending twist is applied to the portable device on which the LCD module 1 is mounted, the LCD 2 does not peel off from the frame 15, so The bending can be prevented, and the action of mechanical stress on the LCD 2 can be prevented.

  In addition, it is the dimension of the clearance which pulled the thickness of the double-sided tape 22 from the thickness of the back polarizing plate 6 that can absorb the thickness which the LED part protruded.

  According to the first embodiment as described above, for example, even when the LED chip 17 cannot be thinned and becomes relatively thick, it is possible to realize a thinning as a module.

  The reason is that the double-sided tape 22 is configured to have a step, and is fixed to the back polarizing plate 6 at the lower step portion and to the back glass 5 at the higher step portion, so that the thickness protruding at the LED chip portion is increased. It was because it was able to absorb.

  As a further effect, by fixing the stepped portion of the double-sided tape 22 to the back glass 5, the area where the backlight module 14 and the LCD 2 are bonded can be expanded, and the glass having a smooth surface and high hardness. And the double-sided tape 22 are bonded to each other, so that even if a mechanical stress such as a drop impact or bending twist is applied to the portable device on which the LCD module 1 is mounted, the LCD 2 is not peeled off from the frame 15, so Can be prevented, and the action of mechanical stress on the LCD 2 can be prevented.

[Second Embodiment]
Next, a second embodiment will be described with reference to the drawings.

  FIG. 5 is a cross-sectional view showing an LCD backlight module 30 according to the second embodiment. The LCD backlight module 30 is configured in the same manner as the LCD backlight module 14 according to the first embodiment (FIGS. 1, 2, and 4) except for the points described below. The LCD module 1 held by the LCD backlight module 30 is the same as that of the first embodiment (FIGS. 3 and 4).

  As shown in FIG. 5, in the case of the present embodiment, the reflective sheet 18 is bonded to the frame 15 by expanding the area of the reflective sheet 18 and providing a notch 31 in a portion that contacts the reflective sheet 18 on the inner side surface of the frame 15. It is configured.

  That is, the LCD backlight module 30 has an opening 32 at a portion opposite to the side on which the LCD module 1 is disposed with respect to the holding surface 25, and the LCD module with the holding surface 25 as a reference. The reflection sheet 18 is provided so as to be flush with the end surface 33 on the side opposite to the side where 1 is disposed.

  Thereby, in the case of 2nd Embodiment, the bottom face part of the flame | frame 15 can be deleted. As a result, the total thickness can be reduced by the thickness of the bottom surface of the frame 15.

[Third Embodiment]
Next, a third embodiment will be described with reference to the drawings.

  First, a conventional LCD module holding structure employing a COG (Chip on glass) method and its problems will be described.

  FIG. 8 is a side view of an LCD module 50 adopting a COG (Chip on glass) system, and FIG. 9 is a state of joining the LCD module 50 of FIG. 8 and a conventional LCD backlight module 60 (conventional LCD employing a COG system). It is a sectional view showing a module holding structure.

  As shown in FIG. 8, the COG method is a method in which an LCD driver IC is connected to the front glass 4 or the back glass 5 by heat and pressure using an ACF resin and electrically and physically connected.

  As shown in FIG. 8, in the holding structure of the LCD module adopting the COG method, in order to prevent the LCD driver IC 11 from malfunctioning due to light, a light shielding tape 23 is provided on the back side of the back glass 5 on which the LCD driver IC 11 is mounted. It is necessary to paste.

  FIG. 6 is a sectional view showing an LCD module holding structure by the LCD backlight module 40 according to the third embodiment. The LCD backlight module 40 is configured in the same manner as the LCD backlight module 14 according to the first embodiment (FIGS. 1, 2, and 4) except for the points described below. The LCD module held by the LCD backlight module 40 is the LCD module 50 shown in FIG.

  As shown in FIG. 6, in the present embodiment, the area of the double-sided tape 22 having a light shielding property is extended to the lower part of the LCD driver IC 11, and the double-sided tape 22 can also function as the light shielding tape 23. That is, the double-sided tape 22 extends to a position that covers the back side of the LCD driver IC 11 included in the LCD module 50. As a result, the light-shielding tape 23 is not necessary, and the cost can be reduced.

  The LCD backlight modules 14, 30, and 40 described in the above embodiments and the LCD module holding structure using them can be preferably applied to a mobile phone or other portable electronic devices. The present invention can also be suitably applied to electronic devices other than portable types.

It is a front view which shows the LCD backlight module which concerns on 1st Embodiment. It is a sectional side view which shows the LCD backlight module which concerns on 1st Embodiment. It is a figure which shows the LCD module hold | maintained by the backlight module which concerns on 1st Embodiment, (a) is a front view, (b) is a side view. It is a sectional side view which shows the holding structure of the LCD module by the LCD backlight module which concerns on 1st Embodiment. It is a sectional side view which shows the LCD backlight module which concerns on 2nd Embodiment. It is a sectional side view which shows the holding structure of the LCD module which concerns on 3rd Embodiment. It is a sectional side view which shows the holding structure of the conventional LCD module. It is a sectional side view which shows the other example of an LCD module. FIG. 9 is a side sectional view showing a conventional holding structure of the LCD module of FIG. 8.

Explanation of symbols

1 LCD module 2 LCD
5 Back glass 6 Back polarizing plate 14 Backlight module 15 Frame 18 Reflective sheet 22 Double-sided tape

Claims (8)

In an LCD backlight module holding an LCD module with an LCD,
The LCD has a first step across a back surface of a back glass provided in the LCD and a back surface of a back polarizing plate provided on the back surface of the back glass,
In the LCD backlight module, the holding surface for holding the LCD module has a second step corresponding to the first step,
In the holding surface, while the upper step portion with the second step as a boundary is bonded to the back glass by a double-sided tape and holds the back glass,
The LCD backlight module, wherein the lower surface of the holding surface having the second step as a boundary is bonded to the back polarizing plate by the double-sided tape to hold the back polarizing plate. The LCD backlight module has an opening at a portion opposite to the side where the LCD module is disposed with respect to the holding surface,
The reflection sheet is provided in the opening so as to be flush with an end surface opposite to a side on which the LCD module is disposed with respect to the holding surface. LCD backlight module.   The LCD backlight module according to claim 1, wherein the double-sided tape has a light shielding property.   The LCD backlight module according to claim 3, wherein the double-sided tape extends to a position covering a back side of an LCD driver included in the LCD module.   An LCD module holding structure, wherein the LCD module is held by the LCD backlight module according to claim 1.   An electronic apparatus comprising the LCD module holding structure according to claim 5.   The electronic device according to claim 6, wherein the electronic device is a portable electronic device.   The electronic device according to claim 7, wherein the electronic device is a mobile phone.

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