JP3695265B2 - Display device and electronic device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device that displays images such as characters, numbers, figures, and the like, and an electronic apparatus configured using the same.
[0002]
[Prior art]
Currently, display devices such as liquid crystal devices are widely used as display devices for electronic devices such as mobile phones and portable information terminals, and are used to display images such as characters, numbers, figures, and the like.
[0003]
In general, a liquid crystal device controls the alignment of liquid crystal by controlling a voltage applied to liquid crystal sandwiched between a pair of substrates. Then, a liquid crystal driving IC is connected to the substrate in order to control the voltage applied to the liquid crystal. As a method for connecting the liquid crystal driving IC to the substrate in this way, conventionally, a COG (Chip On Glass) method in which the liquid crystal driving IC is directly mounted on the substrate, or TAB (Tape Automated Bonding). Various methods are known, such as a TAB method in which a TCP (Tape Carrier Package) is formed by bonding a liquid crystal driving IC on an FPC (Flexible Printed Circuit) using this technique, and the TCP is connected to a substrate. .
[0004]
Considering a COG type liquid crystal device, after mounting a liquid crystal driving IC on a substrate, a connection substrate, usually a flexible substrate, is connected to the input terminal of the substrate, and the connection substrate is interposed therebetween. A liquid crystal driving voltage and a control signal are transmitted to the liquid crystal driving IC.
[0005]
[Problems to be solved by the invention]
The conventional COG type liquid crystal device has a problem that a flexible substrate connected to a substrate on which a liquid crystal driving IC is mounted is easily damaged by bending. There is also a problem that the liquid crystal driving IC is likely to malfunction because light enters the active surface of the liquid crystal driving IC mounted on the substrate through the substrate.
[0006]
Conventionally, as disclosed in, for example, JP-A-60-182679, although it is not a COG type liquid crystal device, its flexibility is used to reinforce the mechanical strength of a flexible substrate connected to the substrate. A technique of attaching a reinforcing member to a substrate is known. However, the technology of providing the reinforcing member as described above in the COG type liquid crystal device has not been proposed in the past, and such a reinforcing member is also used for other purposes in relation to the COG type mounting structure. The idea of doing so has not been proposed in the past.
[0007]
The present invention has been made in view of the above-described problems. In a display device such as a liquid crystal device, the present invention is for reinforcing a flexible substrate connected to a substrate and driving directly mounted on the substrate. An object of the present invention is to simultaneously achieve a plurality of actions of shielding light entering an IC, that is, an IC chip, with a simple configuration.
[0008]
[Means for Solving the Problems]
(1) In order to achieve the above object, a display device according to the present invention is connected to a substrate of the display device, an IC chip mounted on the substrate, and a surface of the substrate on which the IC chip is mounted. In a display device having a flexible substrate disposed so as to protrude from the substrate,
The sheet member mounted on the surface of the substrate opposite to the surface on which the IC chip is mounted is mounted wider than the planar size of the IC chip at a position that blocks light incident on the IC chip through the substrate. The flexible substrate is attached to the flexible substrate along an end surface of the substrate on the side where the flexible substrate protrudes.
[0009]
According to this display device, both the actions of increasing the bending strength of the flexible substrate and preventing light from entering the IC chip through the substrate can be achieved simultaneously by the action of the sheet member. .
[0010]
(2) In the display device according to (1), a length of the portion of the sheet member attached to the substrate in a width direction of the flexible substrate is equal to that of the flexible substrate of the sheet member. It is desirable that it is larger than the width of the portion to be mounted. By doing this, the strength of the sheet member can be sufficiently maintained, and therefore the reinforcement of the flexible substrate becomes even stronger.
(3) In the display device according to the above (1) or (2), the sheet member has a size exceeding an edge of a surface on which the IC chip is mounted, and the substrate is defined by the excess portion. It is desirable to cover the end face. In this way, it is possible to more reliably prevent light from entering the IC chip, and further to protect the side end surfaces of the substrate that are easily damaged such as cracks from the damage.
[0011]
(4) With respect to the display device according to any one of (1) to (3), the display device includes a control substrate provided at a position not facing the IC chip with respect to the substrate, and the flexible substrate includes: The sheet member is bent inside and bent to the opposite side of the surface of the substrate on which the IC chip is mounted and connected to the control substrate.
[0012]
If the configuration described in any one of (1) to (3) is applied to the display device having this configuration, damage to the flexible substrate bent at a large bending angle can be reliably prevented, and the back side of the substrate can be prevented. The light shielding effect on the IC chip can be further enhanced by the synergistic effect of the flexible substrate and the sheet member bent to the left.
[0013]
(5) Next, an electronic apparatus according to the present invention is an electronic apparatus including a display device, a control circuit, and an electrical connection member that electrically connects the display device and the control circuit. The display device according to any one of (1) to (4) is configured.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 shows an embodiment of a liquid crystal device as a display device according to the present invention. The liquid crystal device 1 shown here has a pair of substrates 2 a and 2 b facing each other, and these substrates are bonded to each other by a sealing material 3. The liquid crystal is sandwiched in the gap between the pair of substrates 2a and 2b in the portion surrounded by the sealing material 3. In addition, as shown in FIG. 2, the conductive material 4 is included inside the sealing material 3. Further, a liquid crystal injection port 3a is formed in a part of the sealing material 3 as shown in FIG.
[0015]
In FIG. 2, the first substrate 2a has a substrate material 6a. On the liquid crystal side surface of the substrate material 6a, that is, the surface facing the second substrate 2b, for example, a plurality of first electrodes 7a acting as a common electrode are provided. An overcoat layer 8a is formed thereon, and an alignment film 9a is further formed thereon.
[0016]
In addition, a polarizing plate 11a as an optical element is attached to the outer surface of the substrate material 6a by, for example, sticking, and a reflection plate 12 as an optical element is attached to the outer surface of the substrate material 6a, for example. That is, in the liquid crystal device 1 of the present embodiment, the upper side surface of FIG. 2 is an image display surface.
[0017]
The second substrate 2b facing the first substrate 2a has a substrate material 6b, and a plurality of second materials that act as segment electrodes, for example, on the liquid crystal side surface of the substrate material 6b, that is, the surface facing the first substrate 6a. An electrode 7b is formed in a predetermined pattern, an overcoat layer 8b is formed thereon, and an alignment film 9b is further formed thereon.
[0018]
Further, a retardation plate 10 as an optical element is attached to the outer surface of the substrate material 6b by, for example, sticking, and a polarizing plate 11b as an optical element is further attached thereto by, for example, sticking.
[0019]
In addition, as an optical element provided in both or one side of the 1st board | substrate 2a and the 2nd board | substrate 2b, another element, for example, a light diffusing plate etc., can be considered as needed other than the above-mentioned thing. Further, the phase difference plate 10 may be disposed on both outer sides of the first substrate 2a and the second substrate 2b, 11a may be a polarizing plate that reflects / transmits according to the polarization axis, and 12 may be a light absorption layer. In addition, other optical elements such as a color filter can be provided on one inner surface of the substrate materials 6a and 6b as necessary.
[0020]
The substrate materials 6a and 6b are formed in a predetermined shape, for example, a rectangular shape or a square shape by using a hard light-transmitting material such as glass or the like, or a light-transmitting material having flexibility such as plastic. The first electrode 7a and the second electrode 7b are formed with a thickness of about 1000 mm by a transparent electrode such as ITO (Indium Tin Oxide), and the overcoat layers 8a and 8b are made of, for example, silicon oxide, titanium oxide, or the like. The alignment films 9a and 9b are formed to a thickness of about 800 mm with a polyimide resin, for example.
[0021]
As shown in FIG. 1, the first electrode 7a is formed in a so-called stripe shape by arranging a plurality of linear patterns in parallel with each other. On the other hand, the second electrode 7b is also formed in a stripe shape by arranging a plurality of linear patterns parallel to each other so as to intersect the first electrode 7a. A plurality of points where these electrodes 7a and 7b intersect in a dot matrix form with a liquid crystal layer in between form a pixel for displaying an image. An area partitioned by the plurality of pixels is a display area for displaying an image such as a character.
[0022]
As shown in FIG. 2, a plurality of spacers 13 are dispersed on the liquid crystal side surface of either the first substrate 2a or the second substrate 2b formed as described above. The sealing material 3 is provided on the liquid crystal side surface in a frame shape as shown in FIG. Further, a liquid crystal injection port 3 a is formed at an appropriate position of the sealing material 3.
[0023]
A uniform dimension held by the spacer 13, for example, a gap of about 5 μm, that is, a so-called cell gap is formed between the substrates 2a and 2b, and the liquid crystal 14 is injected into the cell gap through the liquid crystal injection port 3a. After completion of the above, the liquid crystal injection port 3a is sealed with resin or the like. The liquid crystal panel of the liquid crystal device is configured as described above.
[0024]
In FIG. 1, the first substrate 2 a has a substrate protruding portion 2 c that extends outside the second substrate 2 b and further outside the sealing material 3. The first electrode 7a on the first substrate 2a extends directly to the substrate overhanging portion 2c to form a wiring 15. The second electrode 7b on the second substrate 2b is connected to the wiring 15 on the substrate overhanging portion 2c through the conductive material 4 (see FIG. 2) included in the sealing material 3. Reference numeral 20 denotes an external connection terminal for electrical connection with an external circuit (not shown).
[0025]
In reality, a large number of the electrodes 7a and 7b, the wiring 15 on the substrate overhanging portion 2c connected to them and the external connection terminals 20 are formed over the entire surface of each of the substrates 2a and 2b at very narrow intervals. In FIG. 1 and each figure to be described hereinafter, in order to show the structure in an easy-to-understand manner, those electrodes and the like are schematically shown at intervals wider than actual intervals, and some of the electrodes are not shown. Further, the electrodes 7a and 7b are not limited to being formed in a straight line, but may be formed as a pattern such as an appropriate character or figure.
[0026]
A liquid crystal driving IC 16 is directly mounted on the substrate extension 2c by an ACF (Anisotropic Conductive Film) 17 to form a so-called COG mounting structure. As shown in FIG. 2, the liquid crystal driving IC 16 has a plurality of terminals or bumps 21 on its active surface, that is, the lower surface of FIG.
[0027]
As is well known, the ACF 17 is a conductive polymer film that is used to electrically connect together a pair of terminals with anisotropy. For example, as shown in FIG. Alternatively, it is formed by dispersing a large number of conductive particles 19 in a thermosetting resin film 22.
[0028]
The substrate overhanging portion 2c and the liquid crystal driving IC 16 are thermocompression-bonded, that is, heated under pressure, with the ACF 17 interposed therebetween, thereby adhering the liquid crystal driving IC 16 to the substrate overhanging portion 2c and the bumps 21 of the liquid crystal driving IC 16 A connection having conductivity in one direction is realized between the wiring 15 on the substrate overhanging portion 2c and between the bump 21 of the liquid crystal driving IC 16 and the external connection terminal 20 on the substrate overhanging portion 2c.
[0029]
In FIG. 1, an external connection terminal 20 on a substrate overhanging portion 2c is conductively connected via a ACF 18 to a wiring terminal 24a on an FPC (Flexible Printed Circuit) 23 as a flexible substrate. Further, a part of the sheet member 26 is attached to the back surface of the substrate extension 2c by, for example, sticking, and another part of the sheet member 26 is attached to the back surface of the FPC 23 by, for example, sticking.
[0030]
The sheet member 26 reinforces the mechanical strength of the FPC 23 to be bent, and prevents light from entering the active surface of the liquid crystal driving IC 16, that is, the surface on which the bumps 21 are formed, from the back side of the first substrate 2 a. It is used for the purpose of both prevention, and therefore, it is formed of a dark resin material having a mechanical strength of a certain level or more and having a light shielding property, such as black, and is further shown in FIG. Thus, the active surface of the liquid crystal driving IC 16 is mounted at a position where it covers the back side of the substrate overhanging portion 2c.
[0031]
Further, in FIG. 2, a PCB (Printed Circuit Board) 27 as a control board is mounted on the outer surface of the reflector 12 mounted on the outer surface of the first substrate 2a by, for example, an adhesive or an adhesive. Is done. The PCB 27 is equipped with a circuit for supplying power and control signals to the liquid crystal driving IC 16 and a control circuit for controlling an electronic device in which the liquid crystal device 1 is incorporated, such as a mobile phone.
[0032]
Then, the tip of the FPC 23 is bent to the back side of the first substrate 2a as indicated by the arrow A, and the wiring terminal 24b provided at the tip of the FPC 23 is connected to the terminal 28 formed at the tip of the PCB 27 by, for example, soldering or the like. Conductive connection.
[0033]
In the liquid crystal device 1 configured as described above, a scanning voltage is applied to each of the first electrode 7a and the second electrode 7b for each row by the liquid crystal driving IC 16 and further to the other of the electrodes. By applying a data voltage based on the display image for each pixel, the light passing through each pixel portion is modulated by applying a voltage difference between the two voltages to the liquid crystal layer at each pixel position. As a result of passing through the polarizing plate or the like, images such as letters and numbers are displayed on the outside of the substrate 2a or 2b, in the case of this embodiment, on the outside of the substrate 2b.
[0034]
In the present embodiment, as shown in FIG. 2, since the sheet member 26 is attached by bonding or the like between the back surface of the FPC 23 and the back surface of the substrate overhanging portion 2c, the FPC 23 is attached as indicated by an arrow A as in the present embodiment. Even if it is bent with a large curvature, the FPC 23 can be reliably prevented from being damaged.
[0035]
Furthermore, since the sheet member 26 of the present embodiment has a dark color with a light shielding property, for example, black, and is provided at a position where light can be prevented from entering the active surface of the liquid crystal driving IC 16, the sheet member 26 is active. It is possible to reliably prevent the liquid crystal driving IC 16 from malfunctioning when light enters the surface through the first substrate 2a. That is, in this embodiment, the bending strength of the FPC 23 that is a flexible substrate is increased by one sheet member 26, and light is prevented from entering the active surface of the liquid crystal driving IC 16 through the first substrate 2a. Both actions can be achieved simultaneously.
[0036]
In the present embodiment, in the manufacturing process of the liquid crystal device, the sheet member 26 is attached, that is, only adhered to at least two portions of the FPC 23 and the substrate 2a of the flexible substrate. It is possible to take measures against light shielding by the number of parts. There is a light-shielding method of patterning a light-shielding film on the surface of the substrate 2a facing the active surface of the IC 16, and this can also be used. However, if the light can be shielded only by the sheet member 26, this process is used. Is simple.
[0037]
(Second Embodiment)
FIG. 4 shows another embodiment of a liquid crystal device as a display device according to the present invention. The liquid crystal device 31 according to this embodiment is different from the embodiment shown in FIG. 1 in that the sheet member 26 provided between the substrate extension portion 2c and the FPC 23 is modified. Since the components other than the sheet member can be the same as those shown in FIG. 1, they will be denoted by the same reference numerals, and description thereof will be omitted.
[0038]
The sheet member 36 used in the embodiment shown in FIG. 4 is formed of the same material as the sheet member 26 used in FIG. 1, but has a larger area than the sheet member 26 and the side surface of the substrate overhanging portion 2c. It has a size that exceeds. The part beyond that constitutes a plurality of folding margins 37. The sheet member 36 is mounted on the back surface of the substrate overhanging portion 2c, that is, the surface opposite to the surface on which the liquid crystal driving IC 16 is mounted, covering the active surface of the liquid crystal driving IC 16, and the folding margin 37 is indicated by an arrow. Like B, it is bent toward the side surface of the substrate overhanging portion 2c and further fixed to these side surfaces by adhesion or the like. Further, the sheet member 36 extends to the back surface of the FPC 23 and is fixed thereto by adhesion or the like.
[0039]
Accordingly, as shown in FIG. 5, the side surface of the substrate overhanging portion 2c of the first substrate 2a is shielded by the folding margin 37 of the folded sheet member 36. As a result, similarly to the first embodiment, the light that enters the active surface of the liquid crystal driving IC 16 through the substrate extension 2c can be more reliably shielded by the sheet member 36.
[0040]
(Third embodiment)
FIG. 6 shows an embodiment of a mobile phone which is an example of an electronic apparatus according to the invention. The cellular phone 30 shown here is configured by storing various components such as an antenna 38, a speaker 32, a liquid crystal device 40, a key switch 33, a microphone 34, and the like in an exterior case 41 as a casing.
[0041]
Inside the outer case 41 is provided a control circuit board 42 on which a control circuit for controlling the operation of each component described above is mounted. Further, the liquid crystal device 40 can be configured using the liquid crystal device 1 shown in FIG. 1 or the liquid crystal device 31 shown in FIG. 4, and a wiring cable 43 as an electrical connection member is provided between the liquid crystal device 40 and the control circuit board 42. Electrically connected.
[0042]
In the cellular phone 30, a signal input through the key switch 33 and the microphone 34, reception data received by the antenna 38, and the like are input to the control circuit on the control circuit board 42. Then, the control circuit displays an image such as a number, a character, or a pattern on the display surface of the liquid crystal device 40 based on the various data inputted, and further transmits transmission data from the antenna 38.
[0043]
(Other embodiments)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims.
[0044]
For example, in this embodiment, a liquid crystal device has been described as an example of a display device. However, a self-luminous display device using electroluminescence (EL), a plasma display panel (PDP) using plasma emission, and a phosphor are used. It can also be implemented in various display devices such as the field emission display used. Note that when an EL is used, the display device has only one substrate.
[0045]
For example, although a mobile phone is illustrated as an electronic device in FIG. 6, the liquid crystal device of the present invention can be used for various other electronic devices such as a portable information terminal.
[0046]
【The invention's effect】
According to the display device and the electronic apparatus according to the present invention, the bending strength of the flexible substrate extending from the substrate of the display device is increased, and light is prevented from entering the IC chip mounted on the substrate through the substrate. Both actions can be achieved simultaneously by the action of the sheet member.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a liquid crystal device according to the present invention in an exploded state.
2 is a cross-sectional view showing a cross-sectional structure of a main part of the liquid crystal device shown in FIG.
3 is a plan view of a surface opposite to the image display surface of the liquid crystal device shown in FIG. 1. FIG.
FIG. 4 is a perspective view showing another embodiment of the liquid crystal device according to the present invention in an exploded state.
5 is a plan view of a surface opposite to an image display surface of the liquid crystal device shown in FIG.
FIG. 6 is a perspective view showing an embodiment of an electronic apparatus according to the invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Liquid crystal device 2a, 2b Substrate 2c Substrate overhanging part 3 Sealing material 3a Liquid crystal inlet 6a, 6b Substrate material 7a, 7b Electrode 14 Liquid crystal 15 Wiring 16 Liquid crystal drive IC
23 FPC (flexible substrate)
24a, 24b Wiring terminal 26 Sheet member 27 PCB (control board)
30 Mobile phone (electronic equipment)
31 Liquid crystal device 36 Sheet member 37 Folding allowance

Claims (5)

A display device substrate; an IC chip mounted on the substrate; and a flexible substrate connected to a surface of the substrate on which the IC chip is mounted and disposed so as to protrude from the substrate. In the display device,
The sheet member mounted on the surface of the substrate opposite to the surface on which the IC chip is mounted is mounted wider than the planar size of the IC chip at a position that blocks light incident on the IC chip through the substrate. The display device is attached to the flexible substrate along an end surface of the substrate on the side where the flexible substrate projects. In claim 1,
The length of the width direction of the flexible substrate of the portion of the sheet member attached to the substrate is:
A display device, wherein the width of a portion of the sheet member to be mounted on the flexible substrate is larger. The display device according to claim 1 or 2,
The display device according to claim 1, wherein the sheet member has a size exceeding an edge of a surface on which the IC chip is mounted, and an end portion of the substrate is covered by the excess portion. The display device according to any one of claims 1 to 3,
A control board provided at a position not facing the IC chip with respect to the board;
The display device according to claim 1, wherein the flexible substrate is bent to the opposite side of the surface of the substrate on which the IC chip is mounted, with the sheet member being bent, and connected to the control substrate. In the electronic device which has a display apparatus, a control circuit, and the electrical connection member which electrically connects the said display apparatus and the said control circuit, the said display apparatus is at least any one of Claims 1-4. An electronic apparatus comprising the display device described above.

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