JP3070995B2 - LCD module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal module,
In particular, the present invention relates to a flexible, ultra-thin and ultra-lightweight liquid crystal module.

[0002]

2. Description of the Related Art A conventional liquid crystal panel generally has a structure in which a liquid crystal is sandwiched between a pair of glass substrates. Therefore, from the viewpoint of maintaining strength, the glass plate needs to have a certain thickness. In the case of a large panel, the use of a glass substrate significantly increases the weight of the panel. Therefore, it is necessary to perform stable installation in order to prevent deformation and avoid the influence of vibration. The labor required for panel assembly and maintenance work also increased the overall cost and was impractical. This has hindered the spread of large liquid crystal panels.

On the other hand, in recent years, various liquid crystal panels have been developed which are lightweight and can be bent to some extent to form a curved surface by using a flexible plastic substrate (Japanese Patent Publication No. 1-60834, Japanese Patent Publication No. Kaihei 1-
No. 91113). However, in a liquid crystal panel using the above-mentioned flexible plastic substrate, a printed circuit board cannot be directly mounted on the plastic substrate. Alternatively, there is a problem that the external dimensions of the liquid crystal display device need to be independently arranged at another location, which increases the size of the liquid crystal display device.

Further, a liquid crystal panel is formed of a flexible plastic substrate, and a liquid crystal driving LSI is provided on the back surface of the liquid crystal panel via a reinforcing plate and a circuit board which are bent to some extent.
A liquid crystal display device on which components such as the above are mounted is known. However, in this liquid crystal display device, since the circuit board and the liquid crystal driving LSI are fixed to the liquid crystal panel, when the panel is deformed, the terminals of the liquid crystal driving electrodes formed on the plastic substrate and the liquid crystal There is a problem that stress is generated at a joint portion of the driving LSI with a connection line, and a defect phenomenon such as disconnection or peeling of the panel is likely to occur. In order to avoid occurrence of this defect phenomenon as much as possible, the shape of the panel is determined once. After that, there is a problem that the shape cannot be changed.

Further, since the connection between the circuit board terminal and the external input terminal is generally performed by a method such as soldering, if a defect occurs after mounting the liquid crystal panel, the liquid crystal panel and the circuit board are connected. It is difficult to recycle by replacing them, and there is a problem that the yield may be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and is directed to a liquid crystal module which is flexible, ultra-thin and ultra-light, and in which liquid crystal panels and circuit boards (sheets) can be easily replaced. For the purpose of providing.

[0007]

In order to achieve the above object, a liquid crystal module according to the present invention comprises a liquid crystal panel having liquid crystal sandwiched between two flexible plastic substrates and a flexible circuit mounting a liquid crystal drive TAB. A matrix liquid crystal unit connected to a sheet (FPC), a connector connected to the electrode terminals of the flexible circuit sheet,
And a thin board having an interface connector connected to electrode terminals of an external controller, and the connectors are connected by printed wiring. The matrix liquid crystal unit and the thin board are integrally laminated. Preferably, all the TABs for driving a liquid crystal are collectively mounted on the plane of one flexible circuit sheet.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a liquid crystal display using a liquid crystal module according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of the same liquid crystal module.
As shown in FIG. 1, a liquid crystal module 1 of the present invention is housed inside an exterior including a front panel 101 and a rear panel 102, and is used as a liquid crystal display.

The liquid crystal module 1 comprises a liquid crystal unit 8 having at least a liquid crystal panel unit 10 having a liquid crystal panel 11 and a circuit unit 20 having at least a flexible circuit sheet (FPC) 21 connected thereto.
0 and a thin substrate 60.

As shown in FIG. 2, the liquid crystal panel unit 1
Numeral 0 denotes a polarizing filter 12 disposed on the front (front) side of a liquid crystal panel 11 in which liquid crystal is sandwiched between two thin flexible plastic substrates, and a polarizing filter 13 and a reflector 1 on the back side.
4 are arranged and these are overlapped without any gap.

Here, a liquid crystal driving electrode group is formed on the liquid crystal holding surface of each flexible substrate constituting the liquid crystal panel 11, and this liquid crystal driving electrode group is composed of one flexible substrate. It consists of a segment electrode formed thereon and a common electrode formed on another flexible substrate. Therefore, the liquid crystal panel 11 is of a matrix display type.

As a material for forming the flexible substrate, for example,
Examples include crystalline polymers such as uniaxially or biaxially stretched polyethylene terephthalate, amorphous polymers such as polysulfone and polyethersulfone, polyolefins such as polyethylene and polypropylene, polyamides such as polycarbonate and nylon. Of these, uniaxial or biaxially stretched polyethylene terephthalate, polyether sulfone, and the like are particularly preferable. The two flexible substrates may be made of the same material or different materials. Usually, at least one of the two substrates is made of an optical material. It should be transparent and provided with transparent electrodes.

Preferably, the thickness of the flexible substrate is 0.2 mm or less. As the thickness of the flexible substrate is reduced, the flexible substrate can be freely deformed regardless of the curvature. The preferred thickness of the flexible substrate is from 20 μm to
A flexible substrate having a thickness of 1 mm and having such a thickness can be referred to as a flexible film.

The material for forming the liquid crystal driving electrode group 13 formed on the flexible substrate is not particularly limited as long as it is a material having conductivity, but at least one of the electrodes has conductivity and transparency. It is preferable to use a material having both properties. Specifically, for example, ITO (Ind oxide) made of indium oxide or a mixture of indium oxide and tin oxide is used.
A transparent electrode such as an ium tin oxide film is preferably used.
The method for forming the liquid crystal driving electrode on the flexible substrate is not particularly limited, and is formed by a conventionally known method such as evaporation or sputtering.

The liquid crystal material sandwiched between the two flexible substrates is not particularly limited, but a ferroelectric liquid crystal material is preferably used. For example, a liquid crystal material composed of a ferroelectric polymer liquid crystal or a composition thereof is used. Preferably, it is used. Ferroelectric liquid crystal states include ferroelectric low-molecular liquid crystal,
A ferroelectric polymer liquid crystal, a mixture thereof, or the like can be given. Among the ferroelectric polymer liquid crystals, for example, a side chain type ferroelectric polymer liquid crystal having a chiral smectic C phase is preferably used. The polarizing filters 12 and 13 are made of polyvinyl alcohol (PVA) -iodine or PVA.
Those comprising dye-based materials are commonly used.
The polarizing filter is preferably flexible, and therefore, the thickness of the polarizing filter is preferably 0.2 mm or less. The polarizing filters 12 and 13 are disposed on the front and back surfaces of the liquid crystal panel main body in a crossed Nicols state. When a guest-host type liquid crystal is used, a polarizing filter is provided only on the surface (liquid crystal display surface) side. In either case, the polarization filters 12, 13 are
It is attached on a flexible substrate so that the contrast ratio at the time of N-OFF is maximized.

The reflection plate 14 is disposed on the back side (non-display side) of the liquid crystal panel main body. As the reflection plate 14, a metal foil such as aluminum (Al), a sheet formed by bonding a metal foil and a resin film, or the like is used. It is preferable that the thickness of the reflection plate 14 be 0.2 mm or less. If a backlight is provided instead of the reflector, a transmissive liquid crystal display panel can be constructed.

On the front face of the liquid crystal panel unit 10, a color film (color filter) 15 and a protection plate 16 are provided as required. The color film 15 is used for adjusting a color tone. Also, the protection plate 16
Is used to provide necessary safety strength for use.

The circuit unit 20 includes a TAB for driving a liquid crystal.
An insulating sheet 22 and 23 are superposed on both sides of a flexible circuit sheet (FPC) 21 on which a (TAB / LSI) 50 is mounted. For example, as shown in FIG. 3, the circuit sheet 21 has a wiring pattern formed on the front and back surfaces of a 25-μm-thick polyester film or the like, and has two TAB / LSIs 50A and 50B for common electrodes and a segment electrode drive. One TAB / LSI 50C is mounted on a plane and configured as a single sheet, and drives the common electrode and the segment electrode of the liquid crystal panel described above. The connection of the wiring patterns on the front and back surfaces of the circuit sheet 21 is through-hole bonding, and the insulating sheets 22 and 23 are superposed on the front and back surfaces of the circuit sheet to electrically insulate the front and back surfaces of the circuit sheet 21 from the outside.

As a material for forming the circuit sheet 21, a polyester film or a polyimide film having excellent flexibility and heat resistance is preferable. The thickness of the circuit sheet is preferably 0.1 mm or less. The material for forming the wiring pattern (conductive layer) is not particularly limited as long as it is a material having conductivity. However, in order to prevent disconnection even when the wiring sheet is folded, conductive particles such as silver, graphite, and metal are used. Friends alone or with these particles
It is preferable to use those dispersed in a flexible polymer resin binder. As a method of forming a wiring pattern,
Screen printing, photolithography and the like can be mentioned.

As shown in FIG. 4, the liquid crystal driving TAB 50 has lead wires 52a and 52b formed on a tape-shaped base film 51 with a sprocket, and leads 52a and 52b formed on the film have LSI53
Is mounted by TAB (Tape Automated Bonding) method, and LSI mounted on such a film
Will be referred to as a TAB LSI. TAB • LSI is distinguished from a normal LSI in which the LSI is mounted on a lead frame by a wire bonding method. TAB ・ LS
The total thickness of I is preferably 1 mm or less.

As the film for mounting the LSI, polyimide or polyester (P) having excellent flexibility and heat resistance is used.
ET) film or the like is used. An output terminal group 53a is provided at the tip of the lead wire 52a, and an input terminal group 53b is provided at the tip of the lead wire 52b. TAB ・
The output terminal group 53a of the LSI has 160 poles and the input terminal group 53
b is 34 poles.

The wiring pattern on the front side of the circuit sheet 21 is
It is as shown in FIG. In FIG. 5, the segment side electrode terminals 30 (288
The common-side electrode terminals 31 (96) are formed at the right end. Of the 288 segment-side electrodes 30, 160 poles located on the left side are driven by TAB50A (using all 160 poles), and the remaining 128 poles located on the right side are driven by TAB50B (using 128 poles out of 160 poles). The wiring patterns 32A and 32B are formed in such a manner as to be performed. Similarly, 96 common-side electrodes 31 are TAB50C (96 out of 160 poles are used).
The wiring pattern 32C is formed so as to be driven. One side of the wiring patterns 32A to 32C is a heat seal connector section 33A to 33C, and TAB · L
It can be connected to the SI output terminal group 53a by thermocompression bonding. That is, the hot melt resin layer is formed as an adhesive layer on the wiring pattern, and can be connected by thermocompression bonding.

On the front side of the circuit sheet, TAB · L
Circuit patterns 34A to 34C connected to the input terminals 53b of the SIs 50A to 50C are formed. One side of the wiring patterns 34A to 34C is a heat seal connector portion 3
5A to 35C, and can be connected to the input terminal group 53b of the TAB / LSI 50 by thermocompression bonding. Each of the wiring patterns 34A to 34C has a through hole 36.
A to 36C are connected to a wiring pattern on the back side (described later). The wiring pattern on the back side is a through hole 37
And is connected again to the input / output bus 38 on the front side, and is integrated into lock connector connection electrode terminals 39 (26 electrode terminals) provided at the other end of the input / output bus 38. Since the lock connector connection electrode terminal 39 is too weak in terms of strength if it is a flexible sheet (thickness: 25 μm), a 0.3 m thick plastic reinforcing plate is attached.
The thickness is about m.

FIG. 6 is a diagram showing a circuit pattern on the back side of the circuit sheet 21. The input terminals of the TABs 50A and 50B on the front side are connected to 34 segment common buses 40 through the through holes 36A and 36B.
C is also connected from the through hole 36C to the common common bus 41. This is also 34. Segment common bus 4
0 and the common common bus 41 are selectively coupled so that predetermined sequence control can be performed. In the connection area 42, the segment common bus 40
In the same way, the common area buses are consolidated into six in the connection area 43. This common common bus 43 is used as a control bus 44. The control buses 44 (six) are connected to the segment common bus 40 (20).
And a total of 26 are connected to the front-side input / output bus via the through hole 37. Aggregation is for short-circuiting and selecting common parts.

After the liquid crystal panel unit 10 and the circuit unit 20 are overlapped, the segment electrode and the common electrode of the liquid crystal panel unit and the circuit unit 2
The liquid crystal unit 80 is configured by heat-sealing the segment-side electrode and the common-side electrode of No. 0 and electrically connecting them. Liquid crystal panel unit 10 and circuit unit 20
Is lightly mounted with, for example, a double-sided tape, a cellophane tape, an adhesive, or the like.

As shown in FIG. 7, the thin board (printed board) 60 includes a lock connector 61 connected to the lock connector electrode terminal 39 of the circuit sheet, and an interface connected to the electrode terminal of the external controller. It has a connector 62. The lock connector 61 and the interface connector 62 are connected by a printed wiring 63. The printed wiring 63 is composed of 26 wiring patterns, and electrodes 61a and 62a are provided at both ends. The lock connector 61 is connected to the electrodes 61a (26) by soldering or the like. The electrodes 62a (26) are connected to the interface connector 62.
Are connected by soldering or the like.

The thin substrate 60 is provided with an appropriate number of mounting holes 64 at appropriate positions. The thickness of the thin substrate is appropriately selected, for example, within a range of about 0.1 mm to about 2 to 3 mm. Examples of the material for forming the thin substrate include resins such as epoxy and polyester, and composites of these with glass fibers.

The thin substrate 60 is provided with the liquid crystal unit 8 described above.
0 to form the liquid crystal module 1 integrally. That is, as shown in FIG.
The liquid crystal module 1 is integrally formed by superposing a thin substrate 60 on the rear surface of the liquid crystal module 1. In addition, the thin substrate 6
Preferably, a frame-shaped spacer 70 for averaging the thickness of the liquid crystal unit 80 is interposed between 0 and the liquid crystal unit 80. It is preferable that the thin substrate 60 and the liquid crystal unit 80 are lightly adhered with, for example, a double-sided tape, a cellophane tape, an adhesive, or the like.

The lock connector 61 on the thin substrate 60
It is electrically connected to the lock connector connection terminal 39 on the circuit sheet 21. The lock connector can be freely inserted and locked with a lever to ensure electrical connection. Similarly, if the lock is released by lever operation, the electrode terminal can be freely removed without requiring any force. Therefore, even if a defect occurs after mounting the liquid crystal panel, the liquid crystal panel and the circuit sheet can be replaced to easily reuse parts other than the liquid crystal unit, thereby improving the yield.

FIG. 8 is a plan view showing the connection state of the entire liquid crystal module. The segment electrode is shown at the upper end, and the common electrode is shown at the right end. When the liquid crystal panel is viewed from the front, the upper left end of the display is the origin of the display coordinates, so that the common electrode C1 in the first row and the segment electrode S1 in the first column are at the upper right end when viewed from the back. Similarly, the full scale coordinates of C ₁ , S ₂₈₈ , C ₉₆ , S ₁ , C ₉₆ , and S ₂₈₈ are given.

When an appropriate control signal is applied to the liquid crystal module having the above-described configuration from an external control device via the interface connector 62, the control signal is applied to the thin substrate 6
Of the TAB / LSI 50A to 50C on the circuit sheet 21 via the printed wiring 63 and the lock connector 61 on the
And the output signal of the TAB LSI
Liquid crystal drive voltage is applied to the C ₁ -C ₉₆ to the segment electrode S ₁ to S ₂₈₈ and the common electrode of the liquid crystal panel, thereby performing a liquid crystal display.

Since the liquid crystal module of the present invention is flexible, ultra-light and ultra-thin, it can be used not only in a single layer, but also, for example, in a multi-layer display by overlapping several layers. Can be performed. In addition, by suitably combining with a color filter, it has excellent features such as easy color display.

The present invention is not limited to the above embodiment,
The present invention is appropriately modified and implemented within the scope of the present invention. For example, the number of segment electrodes and common electrodes of the liquid crystal panel is appropriately designed, and the wiring pattern of the circuit sheet, the number of TAB / LSI, and the like are designed accordingly. Further, the lock connector and the interface connector can be replaced by a connector having a function equivalent to these.

[0034]

As described above, the liquid crystal module of the present invention is flexible, ultra-light and ultra-thin. Further, conversion of a liquid crystal panel or a circuit sheet is easy.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a liquid crystal display using a liquid crystal module of the present invention.

FIG. 2 is an exploded perspective view showing a liquid crystal module according to one embodiment of the present invention.

FIG. 3 is a plan view showing a TAB-mounted flexible circuit sheet for driving a liquid crystal.

FIG. 4 is a plan view showing a TAB for driving a liquid crystal.

FIG. 5 is a plan view showing a wiring pattern on a front side of a circuit sheet.

FIG. 6 is a plan view showing a wiring pattern on the back side of a circuit sheet.

FIG. 7 is a plan view showing a thin substrate.

FIG. 8 is a diagram showing the overall connection state of the liquid crystal module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Liquid crystal module 10 ... Liquid crystal panel unit 11 ... Liquid crystal panel 20 ... Circuit unit 21 ... Circuit sheet 50 ... Liquid crystal drive TAB 60 ... Thin board 61 ... Lock connector 62 ... Interface connector 80 ... Liquid crystal unit

Continuation of the front page (56) References JP-A-3-96921 (JP, A) Practical application Photograph of the contents of the specification and drawings attached to the application form of Japanese Patent Application No. 63-164569 (Japanese Utility Model Application No. 2-85473) Microfilm (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/1345

Claims (2)

(57) [Claims] 1. A matrix liquid crystal unit comprising a liquid crystal panel having liquid crystal sandwiched between two flexible plastic substrates and a flexible circuit sheet (FPC) on which a liquid crystal drive TAB is mounted; A connector connected to the electrode terminals of the sheet, and an interface connector connected to the electrode terminals of the external controller; a thin substrate formed by connecting these connectors by printed wiring; and And a liquid crystal module, wherein the liquid crystal module is formed by integrally superposing the thin substrate. 2. The liquid crystal module according to claim 1, wherein all of the liquid crystal driving TABs are mounted together on a plane of one flexible circuit sheet.