JP2014191021A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device having improved durability against an impact such as falling by increasing fixing strength of a liquid crystal display panel to a lower frame.SOLUTION: The liquid crystal display device includes a liquid crystal display panel LCP, a cover panel CP fixed to the top face of the liquid crystal display panel via a transparent resin adhesive layer TR, a backlight device disposed on the back face of the liquid crystal display panel, and a lower frame LFR in a box shape which is open at an upper face side and accommodates the liquid crystal display panel and the backlight device; and the liquid crystal display panel and the backlight device are adhered and fixed by an adhesive layer AD provided between an edge of the liquid crystal display panel and the backlight device. The display device has an engaging portion CO formed on a side face of the lower frame, and also has a fixing member FM which engages with a peripheral edge of the liquid crystal display panel through a gap CG formed between the top face of the liquid crystal display panel and the back face of the cover panel and also engages with the engaging portion of the lower frame.

Description

  The present invention relates to a liquid crystal display device, and in particular, a liquid crystal display panel to which a cover panel is fixed via a transparent adhesive layer and a backlight arranged on the back surface of the liquid crystal display panel are in a box shape with an upper surface opened. The present invention relates to a liquid crystal display device housed in a lower frame.

  Thin liquid crystal display devices are used as display devices for many portable information devices such as mobile phones, personal digital assistants (PDAs), digital cameras, and multimedia players.

Among them, in recent years, a so-called screen-fit type liquid crystal display device in which a transparent resin is filled between a liquid crystal display panel and a cover panel disposed on the surface of the liquid crystal display panel to integrate them is a portable information device. Widely used as a liquid crystal display.
In the liquid crystal display device having a screen fit structure, since the cover panel and the liquid crystal display panel are integrated, the strength of the liquid crystal display device itself is increased, and resistance to impact due to dropping or the like is improved. In addition, light reflection between the cover panel and the liquid crystal display panel is reduced compared to the method in which the space between the liquid crystal display panel and the cover panel is filled with air. As a result, the light transmittance is improved and image display is performed. This has the advantage of improving the contrast.

The structure of a conventional liquid crystal display device having a screen fit structure will be described with reference to FIGS.
1 and 2 respectively show conventional examples of a liquid crystal display device having a screen fit structure.
These liquid crystal display devices have a common basic structure such as a liquid crystal display panel and a backlight, but the size of the cover panel CP is different. That is, in the liquid crystal display device shown in FIG. 1, the planar size of the cover panel CP is larger than the planar size of the lower frame LFR, and in the liquid crystal display device shown in FIG. 2, the planar size of the cover panel CP is substantially equal to the planar size of the lower frame LFR. It is.

The liquid crystal display device shown in FIG. 1 and FIG. 2 is a module in which a liquid crystal display panel and the backlight are accommodated in a lower frame LFR formed in a box shape with an upper surface made of a highly rigid material such as metal. It is mounted on an actual device such as a mobile phone by fixing the module to the actual device casing.
A backlight is accommodated on the bottom side of the lower frame LFR, and a liquid crystal display panel LCP integrated with the cover panel CP via the transparent resin layer TR is accommodated on the backlight.
Note that an upper polarizing plate UPP and a lower polarizing plate LPP are attached to both surfaces of the liquid crystal display panel LCP.

The liquid crystal display panel LCP has a configuration in which liquid crystal is sealed between two transparent substrates. For example, one transparent substrate has electrodes and wirings for driving the liquid crystal, and switching elements configured with thin film transistors. Arranged and constitutes a TFT substrate. On the other transparent substrate, a color filter is arranged to constitute a color filter substrate.
The backlight includes a backlight frame BLF having a light source such as an LED, a light guide plate LGP that guides light reflected from the light source and reflects it toward the liquid crystal display panel LCP, and directs light from the light guide plate LGP to the liquid crystal display panel. And an optical sheet OS such as a diffusion sheet that diffuses uniformly, and a reflection sheet RS laid on the bottom surface of the light guide plate LGP.
Therefore, the liquid crystal display panel LCP displays an image by transmitting light emitted from the backlight.

The conventional liquid crystal display device as described above accommodates the liquid crystal display panel LCP and the backlight device integrated with the cover panel CP in the lower frame LFR, and the edge of the liquid crystal display panel LCP and the backlight frame of the backlight device. The BLF is bonded and fixed by an adhesive layer AD such as a light-shielding double-sided tape, and is modularized in the lower frame LFR.
In order to increase the effective display area of the liquid crystal display panel LCP, even if the adhesive layer AD is provided on the entire periphery of the liquid crystal display panel LCP, the total adhesive area of the adhesive layer AD cannot be increased so much.

3 and 4 show a structure for mounting the liquid crystal display device thus modularized on an actual machine, that is, a structure for fixing to an actual machine housing PKG.
3A and 3B show examples of a liquid crystal display device module in which the planar size of the cover panel CP is larger than the planar size of the lower frame LFR as shown in FIG. 1, that is, the cover panel CP projects sideways. Each is shown.
In such a liquid crystal display device, as shown in FIG. 3A, the protruding portion of the cover panel CP is adhered and fixed to the actual housing PKG with an adhesive layer AD1 such as a double-sided adhesive tape, or FIG. ), The overhanging portion of the cover panel CP is held down and fixed by the edge of the actual machine housing PKG.

  On the other hand, as shown in FIG. 2, the planar size of the cover panel CP is substantially equal to the planar size of the lower frame LFR, that is, in the liquid crystal display device having no overhanging portion of the cover panel CP as shown in FIG. The lower frame LFR is bonded and fixed to the actual housing PKG with an adhesive layer AD2 such as a double-sided adhesive tape.

Here, the actual device such as a mobile phone or a digital camera on which the liquid crystal display device is mounted may cause a situation where the user may inadvertently drop the device. In such a case, a force for pulling out the mounted liquid crystal display device (for example, a force for pulling the liquid crystal display device upward in the drawing in FIG. 3) is applied depending on the drop mode.
In such a case, if the mounting structure is as shown in FIG. 3, in addition to the adhesive force of the adhesive layer AD that fixes the liquid crystal display panel LCD by the adhesive layer AD to the backlight frame BLF, the cover panel CP is mounted on the actual housing. It is possible to prevent the liquid crystal display device from jumping out of the actual machine housing PKG due to the adhesive force of the adhesive layer AD1 fixed to the PKG and the force with which the actual machine housing PK engages and suppresses the cover panel CP.

  However, in the mounting structure as shown in FIG. 4, the cover panel CP and the liquid crystal display panel LCP which are relatively heavy are only fixed by the adhesive layer AD having a relatively small area. As shown, when the force F for pulling out the mounted liquid crystal display device is applied, the adhesive layer AD may be peeled off and the liquid crystal display panel LCP may jump out of the actual housing PKG.

  Patent Document 1 discloses a point load on a liquid crystal display panel having a so-called hybrid panel structure in which a front panel is fixed to a polarizing plate on the viewer side of the liquid crystal display panel via an adhesive having a refractive index equivalent to that of the polarizing plate. In addition, a technique relating to an improvement in resistance to vibration stress is disclosed.

JP 2010-60704 A

The problem to be solved by the present invention is to increase the fixing strength of the liquid crystal display panel to which the cover panel is fixed to the lower frame.
That is, an object of the present invention is to provide a liquid crystal display device with improved resistance to impacts such as dropping by solving the above-described problems.

In order to solve the above problems, the liquid crystal display device of the present invention has the following technical features.
(1) A liquid crystal display panel, a cover panel fixed to the surface of the liquid crystal display panel via a transparent adhesive layer, a backlight device disposed on the back surface of the liquid crystal display panel, and a box shape with an open top surface A liquid crystal display panel and a lower frame that accommodates the backlight, and the liquid crystal display panel and the backlight are provided between an edge of the liquid crystal display panel and the backlight. In the liquid crystal display device bonded and fixed by the adhesive layer, an engagement portion is formed on the side surface of the lower frame, and the liquid crystal is passed through a gap formed between the front surface of the liquid crystal display panel and the back surface of the cover panel. It has a fixing member engaged with the peripheral part of a display panel, and engaging with the engaging part of the said lower frame.

(2) In (1), the fixing member has a shape straddling an adjacent side surface intersecting a side surface where the engaging portion of the lower frame is formed.

(3) In the liquid crystal display device described in (1) or (2), the fixing member is provided on each of opposite side edges of a rectangular liquid crystal display panel.

  As a typical effect of the present invention, it is possible to increase the fixing strength of the liquid crystal display panel to which the cover panel is fixed to the lower frame, thereby improving the resistance to impact such as dropping. Can be provided.

It is side surface sectional drawing explaining an example of the conventional liquid crystal display device which has a screen fitting structure. It is side surface sectional drawing explaining the other example of the conventional liquid crystal display device which has a screen fitting structure. It is side surface sectional drawing explaining the fixation structure to the actual machine housing | casing of the conventional liquid crystal display device shown in FIG. It is side surface sectional drawing explaining the fixation structure to the real machine housing | casing of the conventional liquid crystal display device shown in FIG. It is a figure explaining the malfunction by the fixing structure shown in FIG. It is side surface sectional drawing explaining the liquid crystal display device based on one Example of this invention. It is a top view explaining the liquid crystal display device which concerns on one Example of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the liquid crystal display device based on one Example of this invention, (a) is a side view, (b) is an enlarged view of the A section in (a), (c) is B in (a). It is an arrow view. It is a perspective view explaining the fixing member of the liquid crystal display device which concerns on one Example of this invention.

Hereinafter, the liquid crystal display device according to the present invention will be described in detail using a preferred embodiment.
FIG. 6 is a side sectional view for explaining one embodiment of the liquid crystal display device according to the present invention.
The liquid crystal display device of this example includes a liquid crystal display panel LCP, a cover panel CP fixed to the surface of the liquid crystal display panel LCP via a transparent adhesive layer TR, and a back disposed on the back surface of the liquid crystal display panel LCP. A liquid crystal display panel LCP and a lower frame LFR that accommodates the backlight, the liquid crystal display panel LCP and the backlight having the liquid crystal display In the liquid crystal display device bonded and fixed by the adhesive layer AD provided between the edge of the panel LCP and the backlight, an engaging portion CO is formed on the side surface of the lower frame LFR, and the liquid crystal display panel LCP The front panel engages with the peripheral edge of the liquid crystal display panel LCP through a gap CG formed between the front surface and the back surface of the cover panel CP. And having a fixing member FM to be engaged with the engaging portion CO of the lower frame LFR.

Since the basic configuration of the liquid crystal display device of the present embodiment is the same as that of the conventional liquid crystal display device shown in FIG. 2, the redundant description of the parts and functions already described is omitted.
As will be described in detail below, the liquid crystal display device of the present embodiment is mainly characterized in a configuration in which the lower frame LFR and the liquid crystal display panel LCP are fixed by a fixing member FM, as shown in FIGS. There is.

As shown in FIG. 6, a gap CG is formed between the front surface of the liquid crystal display panel LCP and the back surface of the cover panel CP, and the peripheral portion on the upper surface side of the liquid crystal display panel LCP faces the gap CG.
The gap CG may be formed over the entire circumference of the liquid crystal display panel LCP, or may be formed only in a portion where the fixing member FM is provided as will be described later.
Further, the gap CG is formed for the purpose of engaging the fixing member FM as will be described later, and the liquid crystal display panel LCP and the cover panel CP are bonded to the transparent resin adhesive layer TR (in this embodiment, further the upper polarizing plate). If a gap is formed between the front surface of the liquid crystal display panel LCP and the back surface of the cover panel CP when producing an integrated structure with the UPP interposed, the gap can be used as the gap CG. Good.

The lower frame LFR has an engaging portion CO formed on its side surface. As will be described later, the engaging portion CO of the present embodiment is a hole into which the fixing protrusion FP of the fixing member FM is inserted and engaged. is there.
As shown in FIG. 6, the engaging portion CO of this embodiment is a hole that extends through the lower frame LFR to the backlight frame BLF, and the fixing protrusion FP of the fixing member FM is inserted into the hole CO. As a result, the backlight device is also fixed to the lower frame LFR.

The fixing member FM is formed of a material having high rigidity such as a metal, and FIG. 9A shows a perspective view seen from the front side, and FIG. 9B shows a perspective view seen from the back side. In addition, a long plate member is bent into an L shape to form a plane portion PL, and the plane portion PL has a structure in which a plurality of fixing protrusions FP are provided on the other side.
That is, when the cross section of the fixing protrusion FP is viewed, the fixing member FM has a substantially U-shaped cross section as shown in FIG.
The fixing protrusion FP and the hole (engagement portion) CO are provided in shapes, positions, and numbers corresponding to each other, but these shapes, positions, and numbers may be set arbitrarily.

As shown in FIG. 6B, the fixing member FM is inserted from the side of the liquid crystal display device to engage the flat portion PL with the peripheral portion on the upper surface side of the liquid crystal display panel LCP through the gap CG, and the fixing protrusion. The FP is engaged with the hole (engagement portion) CO.
By engaging the highly rigid fixing member FM in this way, the fixing strength of the liquid crystal display panel LCP to which the cover panel CP is fixed to the lower frame LFR is increased. That is, as shown in FIG. 5, when the force F for pulling out the liquid crystal display device due to the fall of the actual machine is involved, the liquid crystal display panel LCP in which the fixing member FM is relatively heavy in addition to the adhesive force of the adhesive layer AD. The situation in which the liquid crystal display device jumps out of the actual housing PKG can be prevented by the force of fixing the frame to the lower frame LFR.

  Here, since the fixing member FM is engaged and attached to the side surface of the lower frame LFR as described above, the thickness dimension (vertical direction dimension in FIG. 6) of the liquid crystal display device module is maintained even when the fixing member FM is attached. Do not increase. As a result, it is possible to avoid a situation where a large design change is required on the actual machine side where the liquid crystal display device module is mounted.

Further, the present invention does not limit the position and range where the fixing member FM is attached to the liquid crystal display panel as long as the fixing member FM can fix the liquid crystal display panel LCP to the lower frame LFR. As shown in FIG. 7, a fixing member FM is provided on each of the opposing side edges of the liquid crystal display panel LCP on which the drive system components (circuit board FPC, etc.) are not provided. ing.
Thus, the fixing member FM can be provided without considering the interference with the driving system component by attaching the fixing member FM to the side without the driving system component (circuit board FPC or the like). Moreover, since the fixing member FM holds the opposite side edges of the liquid crystal display panel LCP over substantially the entire length, the liquid crystal display panel LCP can be more firmly fixed to the lower frame LFR.

Here, in the present embodiment, as shown in FIGS. 8 and 9, end plates FL are formed at both ends of the fixing member FM by bending the plate material into an L shape, respectively. Each has a hole OH that can be said to be a second engaging portion.
In addition, protrusions PRO are formed on adjacent side surfaces (left and right side surfaces in the drawing in FIG. 7) that intersect with the side surface on which the engaging portion CO of the lower frame LFR is provided.

When the fixing member FM is engaged and attached to the liquid crystal display device as described above, the end plate portions FL abut against the adjacent side surfaces, and the projections PRO engage with the holes OH.
That is, by providing the end plate portion FL, the fixing member FM has a shape that is mounted across the adjacent side surface, and when the fixing member FM abuts on the adjacent side surface, the fixing member FM is in its longitudinal direction (gap CG It is possible to prevent displacement in the extending direction). Moreover, since the fixing force similar to the engagement between the fixing protrusion FP and the hole (engaging portion) CO is obtained by the engagement between the protrusion PRO and the hole OH, the fixing force by the fixing member FM is further increased.

In addition, this invention can employ | adopt a well-known various aspect, without being limited to the said Example.
For example, a protrusion may be provided on the side of the lower frame LFR, and a hole as an engaging portion may be provided in the fixing member FM, and the fixing member FM may be attached by engaging the protrusion and the hole.

Further, in a liquid crystal display device of a type in which the planar size of the cover panel CP and the planar size of the lower frame LFR are substantially equal as shown in FIG. 2, the fixed strength is obtained by using the edge of the cover panel CP as shown in FIG. Therefore, the present invention using the fixing member FM is suitable for application to such a type of liquid crystal display device. However, even if the present invention is applied to a liquid crystal display device in which the planar size of the cover panel CP is larger than that of the lower frame LFR as shown in FIG.
Therefore, the present invention is widely applied to a liquid crystal display device in which a liquid crystal display panel and a backlight are accommodated in a box-shaped lower frame having an open top surface and a cover panel fixed via a transparent resin adhesive layer. Can do.

  The present invention is a liquid crystal display device such as a mobile phone, a personal digital assistant (PDA), a digital camera, and a multimedia player. It can be used for a liquid crystal display device of a type that accommodates a fixed liquid crystal display panel and a backlight.

AD: adhesive layer,
BLF: Backlight frame,
CG: gap,
CO: hole (engagement part),
CP: Cover panel
FM: fixing member,
FL: end plate
FP: fixing protrusion,
FPC: Flexible printed circuit,
HO: hole (second engaging portion),
LCP: Liquid crystal display panel,
LFR: lower frame,
LGP: light guide plate,
LPP: lower polarizing plate,
OS: Optical sheet
PKG: Actual machine housing
PL: plane part,
PRO: protrusion,
RS: reflection sheet,
TR: transparent resin adhesive layer,
UPP: Upper polarizing plate,

Claims (3)

A liquid crystal display panel;
A cover panel fixed to the surface of the liquid crystal display panel via a transparent adhesive layer;
A backlight disposed on the back surface of the liquid crystal display panel;
A box-like shape having an upper surface opened; and a lower frame that houses the liquid crystal display panel and the backlight,
In the liquid crystal display device in which the liquid crystal display panel and the backlight are bonded and fixed by an adhesive layer provided between an edge of the liquid crystal display panel and the backlight.
Forming an engaging portion on a side surface of the lower frame;
It has a fixing member that engages with the peripheral portion of the liquid crystal display panel through a gap formed between the front surface of the liquid crystal display panel and the back surface of the cover panel, and engages with the engaging portion of the lower frame. A liquid crystal display device. The liquid crystal display device according to claim 1.
The liquid crystal display device according to claim 1, wherein the fixing member has a shape straddling an adjacent side surface intersecting with a side surface on which the engaging portion of the lower frame is formed. The liquid crystal display device according to claim 1 or 2,
The liquid crystal display device according to claim 1, wherein the fixing member is provided on each of opposite side edges of the rectangular liquid crystal display panel.

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