JPH0545650A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide the liquid crystal display device which enables an EL as a back light to excellently be attached and detached and makes an LE termi nal hard to break during handling. CONSTITUTION:A fixture 14 where a space where the connection part between an EL terminal part 3a and a lead wire 13 can be inserted, an elastic arm 43 for engaging a printed board 2, and an engagement projection 44 provided at the tip part of the elastic arm 43 are formed, is fixed to the terminal lead-out part of the EL 3. At a specific part of the printed board 2, a hole or hollow 27 for engaging the engagement projection 33 is formed. The engagement projection 44 is engaged with the hole or hollow 27 on a snap-in system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device in which an electroluminescence (hereinafter abbreviated as EL) for a backlight is detachably mounted between a liquid crystal display panel and a printed circuit board, and more particularly, to a liquid crystal display device. , EL lead wire connection part protection structure and EL and printed circuit board mounting structure.

[0002]

2. Description of the Related Art An EL used as a backlight of a liquid crystal display panel has a life of about 2000 hours, which is much shorter than that of a liquid crystal display panel. Therefore, in a liquid crystal display device using EL as a backlight, E
L must be constructed so that it can be easily replaced. As a publicly known example having such a configuration, for example, JP-A-3-135595 can be cited.

FIG. 8 is an exploded perspective view of a liquid crystal display device according to the known example. As shown in this figure, the liquid crystal display device of this example includes a liquid crystal display panel 1, a printed circuit board 2, and an E
L3, a holder 4, a spacer 5 having a U-shaped planar shape, and a double-sided tape 6. The liquid crystal display panel 1 is adhered to one surface of the spacer 5 via the double-sided tape 6, and the other surface of the spacer 5 is adhered to the printed circuit board 2 via the double-sided tape 6. The EL 3 is inserted into the space formed between the liquid crystal display panel 1 and the printed board 2 through the opening of the spacer 5. The printed circuit board 2 has a small hole 2a for attaching a holder, and the holder 4 has a projection 4a which can be engaged with the small hole 2a.
Is projected.

In the liquid crystal display device of this example, after the liquid crystal display panel 1, the printed circuit board 2 and the spacer 5 are assembled through the double-sided tape 6, the liquid crystal display panel 1 and the printed circuit board are opened from the opening of the spacer 5. EL3 is inserted in the space formed between 2 and. Next, the protrusion 4a protruding from the holder 4 is engaged with the small hole 2a formed in the printed circuit board 2,
The holder 4 and the printed circuit board 2 make a main body of the EL 3 and the terminal portion 3
a and a lead wire (not shown) connected to this terminal portion 3a
By fixing and, the components are assembled together. When exchanging the EL3, the holder 4 can be removed from the printed board 2 and the EL3 can be pulled out to the opening side of the spacer 5, and the EL3 can be taken out without disassembling the liquid crystal display panel 1 and the printed board 2.

[0005]

By the way, in the liquid crystal display device as described above, normally, before the EL 3 is assembled into the assembly of the liquid crystal display panel 1, the printed circuit board 2 and the spacer 5, the terminal of the EL 3 is assembled. The lead wire is soldered to the portion 3a. This is because, after the EL 3 is incorporated in the assembly, not only the work is difficult but also the heat mounted during soldering may adversely affect the elements mounted on the liquid crystal display panel 1 and the printed circuit board 2.

However, in the liquid crystal display device according to the known example, before the EL3 was incorporated in the assembly, E
No member for protecting the connection between the terminal portion 3a of L3 and the lead wire is provided. For this reason, the EL 3 must be handled with the connecting portion exposed, and the terminal portion 3a of the EL 3 which is weak in strength is easily broken. Further, since the holder 4 is separate from the EL3, in order to fix the EL3 and the lead wire to the printed circuit board 2 with the holder 4, the EL3 and the lead wire are fixed at predetermined positions on the printed circuit board 2. In addition, the holder 4 must be attached to the printed board 2 while holding each of these parts so as to be sandwiched between the holder 4 and the printed board 2, which causes a problem of poor workability.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal display device which is easy to handle and is excellent in the attachment and detachment of the EL.

[0008]

In order to solve the above problems, the present invention provides a lead wire in a terminal portion between a liquid crystal display panel and a printed circuit board having a circuit for driving the liquid crystal display panel. In a liquid crystal display device in which a backlight EL connected to the
A space into which a connecting portion between the terminal portion and the lead wire can be inserted, a resilient arm for engaging with the printed circuit board, and an engagement protrusion provided at a tip portion of the resilient arm. Is formed, and the fixture in which the connecting portion is inserted is fixed in the space, and a hole or a recess for engaging the engaging protrusion is formed in a predetermined portion of the printed circuit board. The EL is set at a fixed position with respect to the printed circuit board by detachably engaging the protrusion with the hole or the depression.

[0009]

As described above, if the fixing member is fixed to the EL and the connecting portion between the EL terminal and the lead wire is inserted into the fixing member, an unreasonable external force is applied to the connecting portion when handling the EL. There is no effect, and inconvenience such as disconnection of the EL terminal portion is eliminated. Also, since the fixture is fixed to the EL, simply insert the EL between the liquid crystal display panel and the printed circuit board and engage the engagement protrusion formed on the fixture with the hole or recess formed on the printed circuit board. The EL can be removably fixed to a predetermined position on the printed circuit board by simply doing so, and therefore the work of mounting and removing the EL on the printed circuit board is significantly facilitated.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exploded perspective view showing an embodiment of a liquid crystal display device according to the present invention, FIG. 2 is a main part plan view showing a mounting state of an EL, a printed circuit board, lead wires and a fixture, and FIG. Is an inside view of the upper member that constitutes the fixture, FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3, FIG. 5 is a view taken along the arrow B of FIG. 3, and FIG. 6 is an inside view of the lower member that constitutes the fixture. 7 is a sectional view taken along line CC of FIG.

As shown in FIG. 1, the liquid crystal display device of this embodiment mainly includes a liquid crystal display panel 1 and a printed circuit board 2.
, EL3, a rubber connector 11 for electrically connecting the liquid crystal display panel 1 and the printed circuit board 2, a metal frame 12 for integrally assembling these members, and a lead wire 13 connected to a terminal portion of the EL3. And a fixture 14 fixed to the terminal lead-out portion of EL3.

Liquid crystal display panel 1, printed circuit board 2, EL
As the rubber connector 11, the metal frame 12, and the lead wire 13, known materials can be used. When these are outlined, the liquid crystal display panel 1 encloses liquid crystal between an upper electrode substrate 21 and a lower electrode substrate 22 which is slightly smaller than the upper electrode substrate 21, and has polarizing plates 23 and 24 on the surfaces of both electrode substrates 21 and 22, respectively. An electrode terminal group for external connection (not shown) is attached to the terminal portion 21a of the upper electrode substrate 21.
Are formed at equal intervals. A circuit (not shown) for driving the liquid crystal display panel 1 is provided on the printed circuit board 2, and a connection terminal 25 is formed on a part of the circuit with the same pitch as the electrode terminal group. In addition, a cutout portion 26 for inserting a leg piece formed in a metal frame 12 which will be described later in detail, and a fixture 14 which will be described in detail later are provided on the printed circuit board 2.
A hole or a recess 27 for engaging the engaging projection formed on the. The rubber connector 11 has a laminated structure in which insulating layers 11a and conductive layers 11b are alternately stacked along the longitudinal direction and at the same pitch as the electrode terminal group and the connection terminal 25, and the conductive layer 11b portion is formed. Is provided between the electrode terminal group and the connection terminal, and they are brought into close contact with each other so that conduction can be achieved. The EL3 is formed by encapsulating a light-emitting body such as ZnS-Mn or ZnS-Cu between a transparent electrode and a lower electrode, and a terminal portion 3a connected to the transparent electrode and the lower electrode from one side edge (FIG. 2). (See) has been pulled out. The metal frame 12 includes the liquid crystal display panel 1 and the printed circuit board 2.
And a rubber connector 11 are integrally assembled, and a front portion 32 having an opening 31 for exposing the display surface of the liquid crystal display panel 1, and four sides of the front portion 32 are erected in one direction. And a leg piece 34 extending from the tip of the side surface portion 33. The leg piece 34 is formed in an inverted T shape with a narrow connecting portion 35 and a wide engaging portion 36 formed at the tip of the connecting portion 35. The lead wire 13 is for connecting the EL 3 to an external device and has the terminal portion 3a at one end.
A core wire for connecting to is exposed, and a connector 37 for connecting to an external device is connected to the other end.

The fixture 14 includes an upper member 14a and a lower member 14
b. As shown in FIGS. 2 to 5, the upper member 14a includes an upper plate 41, a stop plate 42 that is erected vertically from one side edge of the upper plate 41, and the upper plate 41 from the tip of the stop plate 42.
An elastic arm 43 extending in a direction facing the upper plate 41, an engagement protrusion 44 projecting from a tip end portion of the elastic arm 43 facing the upper plate 41, and the stop plate 42 of the upper plate 41.
And a side surface plate 45 standing on the side edge forming a right angle with the standing side edge. The height of the side plate 45 is
It is formed to be lower than the height of the stop plate 42, and the distance d between the upper side of the side plate 45 and the lower surface of the elastic arm 43 is formed to be substantially equal to the thickness of the printed circuit board 2. The elastic arm 4 is attached to the stop plate 42.
A notch 46 for positioning the lower member 14b is formed on both sides of the notch 46 of the upper plate 41.
A semicircular groove 47 for inserting the lead wire 13 is provided in the central portion of the. Further, in the portion of the upper plate 41 following the concave groove 47, the concave portion 4 for accommodating the connecting portion between the terminal portion 3 a of the EL 3 and the lead wire 13.
8 is recessed. Further, small holes 49 for fixing the lower member 14b are formed on both sides of the recessed portion 48 of the upper plate 41 at the recessed position. 3 and 4
Reference numeral 50 in the inside indicates the elastic arm 43 and the engaging projection 4.
4 shows the escape holes of the mold required to mold No.

The lower member 14b is formed in a substantially flat plate shape as shown in FIGS. 6 and 7, and is a protrusion 5 which can be inserted outwardly from one side edge into a notch 46 formed in the upper member 14a.
1 is projected. On the inner surface of the lower member 14b, a semi-circular concave groove which is integrally combined with the concave groove 47 at a portion corresponding to the concave groove 47 formed in the upper member 14a to form a circular lead wire insertion hole. 52 is recessed, and a pin-shaped projection 53 is formed at a portion corresponding to the small hole 49 formed in the upper member 14a so as to have a length capable of penetrating the small hole 49. .. The thickness s of the lower member 14b is formed to be substantially equal to the height h of the side plate 45 erected on the upper member 14a. Reference numeral 54 in FIGS. 6 and 7 indicates an escape groove necessary for avoiding an abutment with the elastic arm 43 when the lower member 14b is combined with the upper member 14a.

A method for assembling a liquid crystal display device using the above-mentioned members will be described below. The rubber connector 11 is interposed between the liquid crystal display panel 1 and the printed board 2, and the electrode terminal group of the liquid crystal display panel 1, the connection terminals 25 of the printed board 2, and the conductive layer 11b of the rubber connector 11 are aligned with each other. To do. Next, the metal frame 12 is attached to the surface of the liquid crystal display panel 1, and the leg pieces 34 of the metal frame 12 are inserted into the notches 26 formed in the side edge portions of the printed circuit board 2. After that, the metal frame 12 is pressed in the compression direction of the rubber connector 11, the connecting portion 35 of the leg piece 34 protruding from the lower surface of the printed circuit board 2 is twisted, and the engaging portion 36 is pressed while the rubber connector 11 is compressed. Engage the back side of. As a result, the electrode terminal group of the liquid crystal display panel 1 and the connection terminal 25 of the printed board 2 are connected to each other by the conductive layer 1 of the rubber connector 11.
It is electrically connected via 1b. Further, a space corresponding to the thickness of the compressed rubber connector 11 is formed between the liquid crystal display panel 1 and the printed board 2.

On the other hand, the lead wire 1 is connected to the terminal portion 3a of the EL3.
3 is connected, and a fixing tool 14 in which a connecting portion between the terminal portion 3a and the lead wire 13 is inserted is fixed to the terminal lead-out portion of El3. The mounting method of the fixture 14 will be described in more detail.
The tip side of the upper member 14a (the side facing the stop plate 42) is brought into contact with the terminal lead-out portion of the EL3, the connection portion is housed in the recessed portion 48 formed in the upper member 14a, and the recessed groove 47 is formed. The lead wire 13 is extended to the outside. Then, the inner surface of the upper member 14a and the inner surface of the lower member 14b are matched with each other, and the lower member 1 is placed in the notch 46 formed in the upper member 14a.
The protrusion 51 formed on the upper member 14a is inserted, and further, the protrusion 53 formed on the lower member 14b is inserted into the small hole 49 formed in the upper member 14a to crimp both members 14a, 14b. . As a result, the connecting portion between the terminal portion 3a and the lead wire 13 is inserted into the fixing tool 14, and the tip portion of the protrusion 53 projects outward from the upper plate 41 of the upper member 14a. Next, while maintaining this state, the tip end portion of the protrusion 53 projecting outward from the upper plate 41 is thermally deformed to integrate the EL 3, the upper member 14a, and the lower member 14b.

In inserting the EL3 to which the lead wire 13 is connected as described above between the liquid crystal display panel 1 and the printed circuit board 2, the light emitting surface of the EL3 is placed on the liquid crystal display panel 1 side. The EL 3 is inserted from the side edge of the lead wire 13 on the non-connection side into the space formed between the liquid crystal display panel 1 and the printed circuit board 2. The upper plate 41 of the upper member 14a and the elastic arm 43 sandwich the side end portion of the printed circuit board 2 and push the stopper plate 42 of the upper member 14a until the side end surface of the printed circuit board 2 comes into contact with the elastic arm 43. The engaging projection 44 provided at the tip of the is engaged with the hole or recess 27 formed in the printed board 2. As a result, the EL 3 with the lead wire is detachably attached to the assembly of the liquid crystal display panel 1 and the printed circuit board 2.

When replacing the EL3, the elastic arm 43 is used.
The tip end of the EL element is deformed in a direction away from the printed circuit board 2 to release the engagement between the engagement protrusion 44 and the hole or the recess 27 formed in the printed circuit board 2, and the EL 3 is connected to the liquid crystal display panel 1 and the printed circuit board 2. Pull out from the assembly with. After that, a new EL 3 to which the lead wire 13 and the fixture 14 are attached in advance is attached by the above method.

It should be noted that the gist of the present invention is to fix a fixing tool 14 for inserting the connecting part between the EL terminal part and the lead wire 13 to the terminal lead-out part of the EL 3, and fix the fixing tool 14 to the printed circuit board 2.
However, the specific configuration of the liquid crystal display panel 1, the printed circuit board 2, the EL 3, the rubber connector 11, the metal frame 12, the lead wire 13, and the fixture 14 is different from the above. The present invention is not limited to the above embodiment. For example, the fixing tool 14 is configured to have a structure in which the lead wire 13 can be attached, and the EL 3 and the lead wire 13 are attached.
It is also possible to prevent not only the bending force but also the tensile force from acting on the connection portion with and. Thus, each of the above-mentioned members is
The design can be arbitrarily changed without departing from the scope of the present invention.

[0020]

As described above, in the liquid crystal display device of the present invention, the fixing member is fixed to the EL, and the connecting portion between the EL terminal and the lead wire is inserted into the fixing member. E
An unreasonable external force does not act on the connecting portion when handling L, and the inconvenience such as disconnection of the EL terminal portion is eliminated. Also, since the fixture is fixed to the EL, simply E
By inserting L between the liquid crystal display panel and the printed circuit board and engaging the engaging protrusion formed on the fixture with the hole or the recess formed on the printed circuit board, the EL can be attached to and detached from the predetermined position on the printed circuit board. Since it can be fixed on the printed circuit board, the work of attaching and detaching the EL to and from the printed circuit board is significantly facilitated.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a plan view of an essential part showing a mounting state of an EL, a printed circuit board, a lead wire and a fixture.

FIG. 3 is an inside view of an upper member that constitutes a fixture.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a view on arrow B of FIG. 3. FIG.

FIG. 6 is an inside view of a lower member that constitutes a fixture.

FIG. 7 is a sectional view taken along line CC of FIG.

FIG. 8 is an exploded perspective view of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 Printed circuit board 3 EL 3a Terminal part 13 Lead wire 14 Fixing tool 27 Hole or dent 43 Elastic arm 44 Engagement protrusion

Claims (1)

[Claims] 1. A backlight electroluminescent device having a lead wire connected to a terminal portion is detachably mounted between a liquid crystal display panel and a printed circuit board having a circuit for driving the liquid crystal display panel. In the liquid crystal display device, a space into which a connecting portion between the terminal portion and the lead wire can be inserted, a resilient arm for engaging the printed circuit board, and an elastic arm An engaging projection provided at a tip portion is formed to fix the fixing tool having the connecting portion inserted in the space, and to engage the engaging projection with a predetermined portion of the printed circuit board. By forming a hole or a recess and detachably engaging the engagement protrusion with the hole or the recess, the electroluminescence is applied to the printed circuit board. A liquid crystal display device characterized by being set in a fixed position.