JPH0739028U - Liquid crystal display - Google Patents

Abstract

(57) [Abstract] [Purpose] A liquid crystal display device integrated with an LCD using EL as a backlight, which enables improvement in workability during assembly and reduction in thickness of a product. A film substrate on the back side of the LCD unit 10 which is sealed with a liquid crystal substance 18, and a front surface side portion of a sealing film 21 of the EL unit 20 which is sealed with an EL light emitting substance 26,
It is formed by the common separation substrate 11. Further, the transparent electrode 13 for LCD is formed on one surface of the front and back surfaces of the separation substrate 11, and the transparent electrode 24 for EL is formed on the other surface. Then, including this separation substrate 11, L
The CD unit 10 is integrated by forming the EL unit 20 on the other surface side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an integrated liquid crystal display device using electroluminescence (EL) as a backlight of a liquid crystal display panel (LCD).

[0002]

[Prior art]

 In recent years, liquid crystal televisions using liquid crystals as display devices have been put into practical use. The liquid crystal is thin, lightweight, and has low power consumption, making it suitable for portable use. However, liquid crystal is a light-receiving element, so a backlight for illumination is required. In the past, fluorescent tubes have been used as the backlight, but since the fluorescent tubes are cylindrical, only the fluorescent tube part emits light, and uniform light cannot be spread over the entire liquid crystal display screen.

[0003] Therefore, there is a direct-type backlight in which a reflective case and a reflective sheet are provided so that the light is evenly spread over the entire liquid crystal display screen, and the linear light source emitted from the fluorescent tube is spread over the entire area. . There is also an edge-light type backlight in which a straight tube type fluorescent tube is arranged on the side end surface of the transparent light guide and one surface side is used as a surface light source by utilizing multiple reflection inside the light guide.

Further, recently, electroluminescence (EL: Electroluminescence), which is structurally excellent as a backlight for a liquid crystal display due to its flexibility in a thin and lightweight surface light source, is used. Has reached the end. An example of a liquid crystal display device using such an EL as a backlight is shown in FIG.

In FIG. 3, 30 is a liquid crystal display panel (LCD: Liquid Crystal Display, hereinafter referred to as LCD) section, and 40 is an EL section. The LCD section 30 is formed by sealing a liquid crystal substance 38 between upper and lower transparent film substrates 31, 32, transparent electrodes 33, 34, alignment films 35, 36 with sealing materials 37, 37. It is an electrode terminal part.

The EL part 40 seals the EL luminescent material 46 between the back electrode 42 and the insulating material 43 on the back side of the sealing film 41 and the transparent electrode 44 on the front side by the sealing material 45. 47 is a lower electrode terminal portion and 48 is an upper electrode terminal portion. The EL section 40 emits the EL light-emitting substance 46 by applying an AC voltage from both electrode terminal sections 47 and 48 to the back electrode 42 and the transparent electrode 44, and is turned on.

In the case where the LCD unit 30 and the EL unit 40 are integrated, it has been conventionally considered that the LCD unit 30 and the EL unit 40 are attached to each other.

[0008]

[Problems to be solved by the device]

 As described above, in the conventional EL backlight integrated LCD, the LCD unit 30 and the EL unit 40 exist independently, and since the LCD unit 30 and the EL unit 40 are attached to each other to be integrated, the number of working steps is reduced. However, there was a defect that the number of products increased and the product became thicker.

Therefore, an object of the present invention is to provide a liquid crystal display device integrated with an EL backlight capable of improving workability at the time of assembly and making the product thinner.

[0010]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention comprises a backlight, which is disposed on the back side of an LCD in which a liquid crystal substance is sealed between front and back film substrates, and an EL light-emitting substance is sealed in a sealing film. In a liquid crystal display device configured by EL, the film substrate on the back side of the LCD and the front surface side portion of the sealing film of the EL are formed by a common separation substrate, and the front and back surfaces including the separation substrate are included. It is characterized in that the LCD is formed on one surface side and the EL is formed on the other surface side to be integrated.

The transparent substrate for the LCD is formed on one surface side of the front and back surfaces of the separation substrate, and the transparent electrode for the EL is formed on the other surface side.

[0012]

[Action]

 Since the film substrate on the back side of the LCD and the front side of the EL sealing film are formed by a common separation substrate, the transparent electrodes for the LCD are on one side of the front and back surfaces of this separation substrate and the EL on the other side. By forming respective transparent electrodes for the LCD, the LCD including the separation substrate can be formed on one surface side of the front and back surfaces thereof, and the EL can be formed on the other surface side thereof to be integrated.

With this, unlike the conventional EL backlight integrated LCD, it is not necessary to attach the LCD section and the EL section that exist independently of each other, and the configuration is simplified, thus reducing the number of work steps. The product can be made thinner.

[0014]

【Example】

 An embodiment of the liquid crystal display device according to the present invention will be described below with reference to FIGS. 1 and 2.

First, FIG. 1 shows an EL backlight integrated liquid crystal display device as an example to which the present invention is applied, in which 10 is an LCD section and 20 is an EL section. The LCD part 10 and the EL part 20 are in a front-back integrated structure with a common separation substrate 11 made of a transparent film as a boundary part.

In the LCD section 10, transparent electrodes 13 and 14 for LCD are formed on the opposite surfaces of the separation substrate 11 on the back surface side and the transparent film substrate 12 on the front surface side, and the alignment films 15 and 16 are formed on the inner surfaces thereof. Are bonded to each other, and the liquid crystal substance 18 is sealed between them by the sealing materials 17, 17 ,. An LCD lower electrode terminal portion 19 from the LCD transparent electrode 13 is formed on the upper surface of the protruding portion extending in the end face direction of the separation substrate 11.

In the EL section 20, the EL back electrode 22 and the EL transparent electrode 24 are formed on the opposing surfaces of the back surface side sealing film 21 and the front surface side separation substrate 11, respectively, and the sealing film 21 is formed. An insulating substance 23 is locked on the inner surface by printing, and an EL light emitting substance 26 is sealed between them by a sealing material 25, 25 ,. Further, an EL lower electrode terminal portion 27 from the EL back electrode is formed on the upper surface of the protruding portion extending in the end face direction of the insulating material 23. The EL upper electrode terminal portion 28 from the EL transparent electrode 24 is formed on the lower surface of the protruding portion extending in the end face direction of the separation substrate 11.

As described above, the back side film substrate of the LCD part 10 and the front side part of the sealing film 21 of the EL part 20 are formed by the common separation substrate 11 made of a transparent film, and the separation substrate 11 is used as a boundary part. The EL backlight integrated liquid crystal display device 29 is configured.

Here, the sealing film 21 is made of a polymer of a trifluorochloroethylene film and polyethylene, and the peripheral edge of the EL portion 20 is thermocompression-bonded to seal the EL light-emitting substance 26 inside. The back electrode 22 for EL uses an opaque metal foil made of aluminum foil or the like, and has a function of efficiently reflecting EL light emission to the LCD 10 part side. The insulating material 23 is made of a material having a high dielectric constant, and is formed by screen-printing a mixture of cyanoethyl cellulose and barium titanate on the back electrode 22 and then drying it. The EL light-emitting material 26 is a light-emitting layer obtained by screen-printing a dispersion of zinc sulfide in cyanoethyl cellulose on the insulating material 23 and drying. The EL lower electrode terminal portion 27 uses a foil piece of copper or aluminum, and a conductive substance such as a conductive paste is used for connection with the back electrode 22, and both are pressure-bonded to achieve conduction.

In the above, as the separation substrate 11, a transparent polymer film having impermeability to water is used, and a material such as PES (polyether sulfone) is used. In the separation substrate 11 made of such a transparent film, the LCD transparent electrode 13 made of ITO (Indium Tin Oxide) or the like is formed on the side (upper surface side) of the LCD part 10 facing the alignment film 15, and the other EL part is formed. On the side facing the surface 20 (the lower surface side), the transparent EL electrode 24 using ITO or the like is similarly formed.

Next, FIG. 2 shows an example of connection with the circuit board 1 of the above-mentioned EL backlight integrated liquid crystal display device 29. Reference numeral 2 is an EL power supply circuit element, and 3 is an LCD lower electrode driver element. A child, 4 is an LCD upper electrode driving element, 5 is a CPU (Central Processing Unit) element, and 6, 7, 8, 9 are connection FPCs (Flexible Printed Circuits). As shown in the figure, an EL power supply circuit element 2, an LCD lower electrode driving element 3, an LCD upper electrode driving element 4, and a CPU element 5 are mounted on the circuit board 1.

First, in order to drive the display of the LCD section 10, the LCD upper electrode drive circuit connecting FPC 6 is connected to the LCD upper electrode terminal portion (not shown), and the LCD lower electrode terminal portion 19 is connected to the LCD lower electrode driving circuit. The respective FPCs 7 are connected to each other via an anisotropic conductive adhesive. A circuit in which the LCD upper electrode drive circuit connecting FPC 6 and the LCD lower electrode drive circuit connecting FPC 7 are mounted with the EL power supply circuit element 2, the LCD lower electrode drive element 3, the LCD upper electrode drive element 4, and the CPU element 5. Each is connected to the substrate 1. The LCD section 10 displays by the drive signals output from the LCD lower electrode drive element 3 and the LCD upper electrode drive element 4.

Further, in order to drive the EL section 20 to light, the EL upper electrode terminal section 28 is provided with an FPC 8 for connecting the EL upper electrode, and the EL lower electrode terminal section 27 is provided with an FPC 9 for connecting the EL lower electrode. Connect via a conductive adhesive. Then, the FPC 8 for connecting the EL upper electrode and the FPC 9 for connecting the EL lower electrode are connected on the circuit board 1, respectively.

The EL power supply circuit element 2 mounted on the circuit board 1 has an inverter function of converting a DC voltage into an AC voltage. The EL power supply circuit element 2 receives a direct current voltage from a battery (not shown) and generates an alternating current voltage, and then, through the EL upper electrode connecting FPC 8 and the EL lower electrode connecting FPC 9, the EL portion 20 By applying an AC voltage to both electrodes 22 and 24, the EL light emitting material 26 is caused to emit light, and the EL portion 20 is turned on.

As described above, according to the liquid crystal display device 29 integrated with the EL backlight, the boundary layer between the LCD section 10 and the EL section 20 is formed by the separation substrate 11 made of a transparent film, and the front and back surfaces of the separation substrate 11 are separated. By using as the transparent electrode 13 for LCD and the transparent electrode 24 for EL, the structure can be simplified as compared with the conventionally conceived one, the number of assembling steps can be reduced, and the product can be made thin.

In the above embodiments, the EL backlight integrated LCD is connected to the circuit board by the connection FPC, but instead of this, for example, a TAB (Tape Automated Bonding) method is used. A tape carrier may be used. In addition, it goes without saying that the specific detailed structure and the like can be appropriately changed.

[0027]

[Effect of device]

 As described above, according to the liquid crystal display device of the present invention, the film substrate on the back side of the LCD and the surface side portion of the sealing film of the EL are formed by the common separation substrate. By forming a transparent electrode for LCD on one surface of the front and back surfaces of this separation substrate and a transparent electrode for EL on the other surface of the separation substrate, the LCD is formed on one surface side of the front and back surfaces including the separation substrate. An EL back light integrated LCD can be obtained by forming ELs on the other surface side.

Therefore, unlike the conventional case, it is not necessary to attach the LCD section and the EL section that exist independently of each other, and the configuration can be simplified. Therefore, the work man-hours at the time of assembly are reduced, and the workability is improved. In addition to being able to achieve this, it is possible to achieve a thin product.

[Brief description of drawings]

1 is a vertical sectional side view showing an example of an EL backlight integrated liquid crystal display device to which the present invention is applied, and is a cross-sectional view taken along the line AA of FIG. 2 showing an example of connection with a circuit board. is there.

FIG. 2 is a schematic perspective view showing an example of connection with a circuit board of a liquid crystal display device integrated with an EL backlight to which the present invention is applied.

FIG. 3 is a vertical sectional side view showing an example of a conventional liquid crystal display device using EL as a backlight.

[Explanation of symbols]

 1 Circuit Board 2 EL Power Supply Circuit Element 3 LCD Lower Electrode Driving Element 4 LCD Upper Electrode Driving Element 5 CPU Element 6, 7, 8, 9 Connection FPC 10 LCD Section 11 Separation Substrate 12 Transparent Film Substrate 13, 14 Transparent Electrode 15 , 16 Alignment film 17 Sealing material 18 Liquid crystal material 19 Electrode terminal part 20 EL part 21 Sealing film 22 Back electrode 23 Insulating material 24 Transparent electrode 25 Sealing material 26 EL light emitting material 27, 28 Electrode terminal part 29 EL backlight integrated type Liquid crystal display

Claims (2)

[Scope of utility model registration request] 1. A backlight arranged on the back side of a liquid crystal display panel in which a liquid crystal substance is sealed between front and back film substrates is constituted by electroluminescence in which a light emitting substance is sealed in a sealing film. In the liquid crystal display device described above, the film substrate on the back side of the liquid crystal display panel and the surface side portion of the sealing film of electroluminescence are formed by a common separation substrate, and the front and back surfaces including the separation substrate are included. 2. A liquid crystal display device, characterized in that the liquid crystal display panel is formed on one surface side and the electroluminescence is formed on the other surface side so as to be integrated. 2. The transparent electrode for the liquid crystal display panel is formed on one surface side of the front and back surfaces of the separation substrate, and the transparent electrode for the electroluminescence is formed on the other surface side of the separation substrate, respectively. Liquid crystal display device.