Patent Application
20130048195
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2011-189197 filed on Aug. 31, 2011, the entire contents of which are incorporated herein by reference.
The present invention relates to the technology of manufacturing a liquid crystal panel obtained by enclosing a liquid crystal between two substrates.
A liquid crystal panel obtained by enclosing a liquid crystal between two substrates has the merit of having a relatively thin and light-weight structure. Therefore, the liquid crystal panel has been widely used as an information display screen of a display device.
Two substrates of a liquid crystal panel are bonded by a sealant. The sealant limits the range of enclosing a liquid crystal between the two substrates. Thus, the liquid crystal is enclosed in the range encompassed by the sealant between the two substrates.
The liquid crystal is injected after fully hardening the sealant. In the stage of bonding the two substrates, the sealant is placed in an unhardened state or a half-hardened state so that the two substrates can be bonded.
The sealant generates a gas when it is hardened. The gas reforms the liquid crystal. The liquid crystal is injected after hardening the sealant. Accordingly, when the sealant is fully hardened, the gas generated from the sealant is forcibly removed.
Not to keep the distance between the two substrates too narrow, it is common to arrange spacers between the two substrates. In addition, when flexible substrates such as films etc. are used, there is a member (structures) for keeping the distance between the two substrates not too wide arranged between the two substrates. The structures are to bond the two substrates like the sealant, and are necessary to perform the hardening process. When the structures are hardened, a gas is generated as with the sealant. When the structures are used, a larger amount of gas is generated, thereby enhancing the probability of the necessity to remove the gas.
A method of removing the gas, decreasing the pressure of a panel, and removing the gas from the space of the sealant through which the liquid crystal is injected is considered. However, since the method requires a heating process using infrared light (infrared ray), there occurs uneven heating when a large number of panels are simultaneously processed. Therefore, the method is not appropriate. In addition, although there is a method of absorbing the gas from the space in the sealant, it is hard to use the method because the gas cannot be appropriately absorbed from the uneven surface of the panel which may have broken portions in the surface.
A method of forcibly removing the gas can be, for example, absorbing the gas from the hole which is made as an aperture in the two substrates respectively. The hole can be made in the two substrates because the substrate having a flat surface can contact the member for absorbing the gas in an appropriate state.
The hole through which the gas is absorbed is made outside the area in which a liquid crystal is enclosed (hereafter referred to as an “enclosed area”) so that the entire area can be used as a display area. To absorb the gas through the hole made outside the area, the sealant is applied to form a path (first path) for enclosing the enclosure area by providing a space for injecting a liquid crystal, and a path (second path) for enclosing the area including the aperture facing the enclosure area with the space interposed (
The sealant before fully hardening is soft and has low adhesive strength. Since it is common that the hole is made using a tool, at least one of the two substrates is subject to a certain level of force when the hole is made. The force may transform the sealant into an inappropriate state. When the sealant enters the inappropriate state, there occurs a problem that, for example, the distance between the two substrates cannot be maintained within an appropriate range. If the structures are arranged, the structures may enter an inappropriate state. Therefore, the processing area has conventionally been kept large so that an undesired influence of the force when raised during the perforating process may be reduced on the sealant enclosing the enclosure area. Hereafter, the inappropriate state of the sealant, the structures, etc. is referred to as “damage”.
The part including the processing area of the substrate and the sealant of the part enclosing the processing area are discarded. Therefore, to reduce the manufacture cost (cost of material) of the liquid crystal panel, it is preferable that the processing area can be smaller. However, if the processing area is smaller, there is a stronger possibility that the sealant encompassing the enclosure area is damaged when the hole is made. The damage of the sealant means an occurrence of a waster during the manufacturing process. A higher probability of the occurrence of the waster increases the manufacture cost. Thus, it is important to reduce the processing area while suppressing the occurrence of the damage of the sealant.
There is a method of making a hole in at least one of the two substrates in advance, to reduce the processing area more efficiently. However, when a perforating process is performed, dust can be made. The dust has to be removed to manufacture a liquid crystal panel because, in the manufacturing process of the liquid crystal panel, as in the process of, for example, generating an electrode on a substrate, the dust can generate a waster at a high probability. Thus, making a hole in advance requires adding the process of removing dust etc. Since adding a process (facility) increases the manufacture cost, it is not preferable to adopt the method of making a hole in advance.
A document of prior art can be, WO2007/102197, Japanese Laid-open Patent Publication No. 2000-155325, and Japanese Laid-open Patent Publication No. 2010-249923.
The present invention aims at providing the technology of suppressing the generation of damage of a sealant for bonding two substrates, and reducing the processing area in which a hole is made in the bonded two substrates.
In the system according to the present invention, when a liquid crystal panel is manufactured by enclosing a liquid crystal between two substrates, a sealant for bonding the two substrates is applied on one of the two substrates along a first path encompassing a first area in which the liquid crystal is enclosed, and a second path encompassing a second area facing the first area with a space provided as an aperture when the liquid crystal is injected, the two substrates to one of which the sealant is applied are bonded, only the sealant applied along the second path is hardened first, and then a hole which is an aperture for forcibly removing a gas generated when the sealant of the first path is hardened is formed.
First, the manufacturing process of a liquid crystal panel that disclosed the manufacturing method of the liquid crystal panel and the perforation device according to the embodiment is applicable is described below with reference to
As illustrated in
After performing the patterning process, as illustrated in
Structures 23 for protection against a large space between the films 10 and 20 are formed on the alignment layer 22 of the reverse film 20 as illustrated in
After forming the structures 23, as illustrated in
The sealant 14 is applied along the path (first path) enclosing an area 15 on which the electrode 11 and the alignment layer 12 of the face film 10 are formed with a space 14a. In addition, the sealant 14 is applied along the path (second path) enclosing another area 16 facing the area 15 from the space 14a. The space 14a is an injection inlet of the liquid crystal. Since the area 15 is a portion in which the liquid crystal is enclosed, it is hereafter referred to as an “enclosure area”. Since the area 16 is a portion in which a hole is made, it is hereafter referred to as a “processing area”.
The sealant 14 is hardened by the irradiation of ultraviolet rays or heating. The sealant 14 applied to the face film 10 is half-hardened (provisionally hardened) after bonding the films 10 and 20 so that the electrodes 11 and 21 face each other as illustrated in
The bonded two films 10 and 20 are cut along the broken line L1 as illustrated in
A heating process for fully hardening the sealant 14 is performed as illustrated in
By the heating process, the sealant 14 and the structures 23 generate a gas. Therefore, when the heating process is performed, a vacuuming process is performed as illustrated in
The bonded film 43 for which the sealant 14 etc. is fully hardened by the heating process is cut to remove a residual portion along the broken line L3. The liquid crystal is injected to a bonded film 46 which is the bonded film 43 after contour cutting process is performed.
As illustrated in
After fully hardening the sealant 14, as illustrated in
As illustrated in
Conventionally, a wide processing area 16 is assigned to suppress the damage of the sealant 14 etc. On the other hand, the present embodiment can reduce the width of the processing area 16 while suppressing the damage of the sealant 14 etc. Although the width of the processing area 16 is reduced from the width b as illustrated in
As illustrated in
The device table 53 is a table on which the bonded film 43 to be processed in the perforating process is placed. The heating head 52 is to heat the sealant 14 of the processing area 16 of the bonded film 43 placed on the device table 53. A heater 52a is arranged as a heat source in the heating head 52.
The body 51 of the device controls the entire perforation device 50, and is provided with a tool 51a for performing the perforating process. The body 51 of the device performs the perforating process on the bonded film 43 placed on the device table 53 by moving the tool 51a up and down.
The body 51 of the device moves the heating head 52 up and down. When the bonded film 43 is heated, the heating head 52 is moved down to the position indicated by the broken line, that is, for example, to the position where the head 52 contacts the bonded film 43. By the movement, the bonded film 43 can be efficiently heated by the heating head 52.
The perforation device 50 having the above-mentioned components is realized by an operator placing the bonded film 43 on the device table 53 and directing the start of the up and down movement of the tool 51a. The perforation device 50 can also automatically perform at least one of placing the bonded film 43 on the device table 53 and performing the perforating process by the up and down movement of the tool 51a.
As illustrated in
A through hole 52b is formed in the heating head 52, and the tool 51a moves up and down through the through hole 52b. The configuration is devised to make the holes 17 and 27 using the tool 51a in the processing area 16 in which the heating head 52 is heated without removing the heating head 52 so that the head 52 cannot touch the tool 51a. Thus, by providing the through hole 52b in the heating head 52, the structure of the perforation device 50 can be simplified.
Although not specifically illustrated in the attached drawings, the device table 53 is provided with a guide for arrangement of the bonded film 43 at an appropriate position. An operator uses the guide to place the bonded film 43 at the appropriate position on the device table 53. Thus, the bonded film 43 placed on the device table 53 enters the state in which the hole 53a is positioned in the processing area 16. The operator then operates the starting switch to direct the up and down movement of the tool 51a.
When the operator operates the starting switch, the heating head 52 is located at the position indicated by the solid line in
The heating operation performed using the heating head 52 is continued until, for example, the sealant 14 in the heating range 61 is fully or substantially fully hardened. When the heating operation is performed, the body 51 of the device lowers the tool 51a without lifting the heating head 52, or lowers the tool 51a while lifting the heating head 52. In this example, for convenience of explanation, it is assumed that the tool 51a is lowered without lifting the heating head 52. It is also assumed that the heating head 52 is lifted while moving the tool 51a up and down. When the heating head 52 is lifted with the timing above, the time taken to move the tool 51a and the heating head 52 can be shorter than in the case in which the tool 51a and the heating head 52 are separately moved.
By the heating operation performed using the heating head 52, the sealant 14 in the heating range 61 of the bonded film 43 is hardened, and the hardened sealant 14 is not easily damaged, thereby successfully standing a higher pressure. Therefore, although the processing area 16 becomes narrower, the sealant 14 is not damaged at the portion enclosing the enclosure area 15 when the perforating process is performed. Although the width of the processing area 16 is changed from the width b as illustrated in
The operation unit 72 is used by the operator to direct various settings and operations. The switches provided for the operation unit 72 include a starting switch 72a for directing the start of the perforating process. Settings are made for the temperature of the heating head 52, the heating time of the heating operation by the heating head 52, etc.
The display unit 78 displays necessary information for the operator. The control unit 71 directs the display unit 78 to display the necessary information depending on the operation of the operator on the operation unit 72. Thus, the operator can make various settings while confirming the information displayed on the display unit 78. The control unit 71 stores the set temperature and heating time of the heating head 52 in memory 71a as process information for the perforating process, and reflects the information in executing the perforating process.
The detection unit 73 detects the bonded film 43 appropriately placed on the device table 53. The detection is performed mechanically or optically, and the detection signal indicating the detection result is output to the control unit 71. The mechanical detection can be performed by arranging one or more switches pressed when the bonded film 43 is appropriately placed on the device table 53. The optical detection can be performed by arranging one or more optical sensors whose amount of photoreception changes when the bonded film 43 is appropriately placed on the device table 53. The detecting method is not limited to the applications above, but other method can also be used.
According to the detection signal input from the detection unit 73, the control unit 71 confirms whether or not the bonded film 43 is appropriately placed on the device table 53 when the starting switch 72a is operated. Thus, the control unit 71 enables the operation on the starting switch 72a only when it is confirmed that the bonded film 43 is appropriately placed on the device table 53.
The motor 74 is a power source for moving the tool 51a up and down, and the motor 75 is a power source for moving the heating head 52 up and down. The motor drive unit 76 is a drive circuit for driving motors 74 and 75 at the instruction from the control unit 71.
The motor drive unit 76 rotates the motor 74 in the same direction for a specified number of rotations upon receipt of the instruction to rotate the motor 74 from the control unit 71. By the number of rotations, the tool 51a moves up and down once, and returns to the position in which it was placed before starting the up and down movement.
On the other hand, when the motor 75 is rotated, the control unit 71 issues an instruction to the motor drive unit 76 including the rotation direction. Through the instruction of the rotation direction, the control unit 71 moves up or down the heating head 52.
Depending on the number of rotations of the motor 75, the amount of movement of the heating head 52 can be adjusted. However, when the heating head 52 is heated with the heating head 52 touching the bonded film 43 or moving the heating head 52 to the vicinity of the bonded film 43, it is necessary to control with high accuracy the amount of movement (down movement) to prevent the heating head 52 from adding the pressure that damages the sealant 14 to the bonded film 43.
Thus, it is necessary to detect the distance between the bonded film 43 and the heating head 52 and control the movement of the heating head 52, or to prepare a system for reducing the pressure of the heating head 52 which has contacted the bonded film 43 to be added to the bonded film 43. In the present embodiment, when the level of the resistance occurring when the heating head 52 is moved equals or exceeds a specified level, a system of interrupting the power transmitted from the motor 75 (for example, a clutch) is prepared, thereby preventing the heating head 52 from applying the pressure that damages the sealant 14 of the bonded film 43.
The control unit 71 recognizes the temperature of the heating head 52 according to the signal from the temperature sensor 51c, and reflects the recognition result on the control of the heater drive unit 77. Thus, the control unit 71 controls the temperature of the heater 52a by driving the heater drive unit 77 so that the temperature of the heating head 52 can match the set temperature. Therefore, by controlling the temperature of the heating head 52, the heating of the bonded film 43 by the heating head 52 can be performed according to the constantly set temperature.
When the operator operates the starting switch 72a, the control unit 71 starts the perforating process on condition that the detection signal from the detection unit 73 indicates the appropriate location of the bonded film 43. The perforating process is performed by the flow of control as follows.
The control unit 71 instructs the motor drive unit 76 to drive the motor 75 before moving the tool 51a up and down, and moves the heating head 52 until it contacts the bonded film 43, and then stops the head 52. Thus, the sealant 14 in the heating range 61 is heated, and is further hardened. Afterwards, the control unit 71 instructs the motor drive unit 76 to drive the motor 74 to moves the tool 51a up and down once to make the holes 17 and 27 in the heating range 61. The control unit 71 instructs the motor drive unit 76 to drive the motor 75 while moving the tool 51a up and down, and lifts the heating head 52. Thus, the drive of the motor 74 or 75 is terminated, thereby terminating the control for performing the perforating process.
The perforation device according to the present embodiment is provided with two motors 74 and 75 for separately moving up and down the tool 51a and the heating head 52, but one motor can perform the up and down movement. Next, a variation example of the perforation device for moving up and down the tool 51a and the heating head 52 using one motor is practically described below with reference to
In this variation example, a plate member 81 is attached to the tool 51a as illustrated in
Thus, by attaching the heating head 52 to the tool 51a, the heating head 52 moves up and down with the up and down movement of the tool 51a. Therefore, in this variation example, the motor 75 is not required, thereby further reducing the manufacture cost.
When the perforating process is performed, the heating head 52 heats the range 61 including the processing area 16 of the bonded film 43. The heating operation is performed by lowering the tool 51a until the heating head 52 contacts the bonded film 43 as illustrated in
As illustrated in
Thus, the control unit 71 in the variation example as illustrated in
In another variation example, as illustrated in
The heating head 90 is provided with a through hole 92 for the up and down movement of the tool 51a. The initial position of the tool 51a, that is, the position immediately before starting the perforating process, is the position in which the end portion of the tool 51a enters the through hole 92 of the heating head 90.
When the perforating process is performed, the infrared light 95 is irradiated from the infrared light lamp 91 to the bonded film 43, and the range 61 including the processing area 16 of the bonded film 43 is heated. After the heating operation, the tool 51a is once moved up and down, and the end portion of the tool 51a reaches the hole 53a of the device table 53, thereby making the holes 17 and 27 in the processing area 16 of the bonded film 43.
In another variation example, as illustrated in
The two variation examples of the perforation devices according to the present embodiment are described above with reference to
Furthermore, according to the present embodiment, the sealant 14 can be applied as illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-189197 | Aug 2011 | JP | national |
