The present invention relates to a method and an apparatus for manufacturing a liquid crystal component, and specifically relates to a method and an apparatus for manufacturing a liquid crystal component, in which when a gap between a panel surface of a liquid crystal module and a transparent cover is filled with a predetermined resin to bond both of them, the bonding can be performed to make a good condition which is targeted.
A display of a liquid crystal module used in cellular phones or various display devices conventionally has an air gap structure in which a gap (air gap) in a range of about 0.5-1 mm is provided between a panel surface of the liquid crystal module and a transparent cover such as a tempered glass plate or an acrylic plate, so as not to influence the liquid crystal module even in a case that the cover is broken by an external impact.
However, in this air gap structure, because a liquid crystal panel of a liquid crystal module, an air layer forming the air gap and the transparent cover made of glass or of plastic have mutually different indexes of refraction and are layered in sequence, there may be caused a reflection of light on each interfacial surface (an interfacial surface between the liquid crystal panel and the air layer, an interfacial surface between the air layer and the transparent cover and an interfacial surface between the transparent cover surface and an external air), so that a brightness may be reduced or so that a contrast ratio may be worsened by a light scattering. For example, the display from the liquid crystal panel sometimes becomes difficult to see under the light of the sun.
For that problem, there has been recently disclosed a technology where the above-described air gap is filled with a transparent optical resin whose index of refraction is close to glass or acrylic and is cured by ultraviolet irradiation, etc. (non-patent document 1). The above-described air gap is filled with this optical resin, so that the interfacial surface between the above-described liquid crystal panel and the air layer and the interfacial surface between the air layer and the transparent cover are substantively eliminated, the reflection or the light scattering on these interfacial surface is eliminated, and the brightness of the display from the liquid crystal panel and the contrast ratio can be greatly improved.
Further, in the above-described improved technology, it is required that the optical resin is formed with no air entrainment, especially with no unnecessary protrusion from the panel part of the liquid crystal module and with no influence on the surrounding members, so that a method and an apparatus for the application and hardening of the optical resin has been required to develop urgently.
Accordingly, an object of the present invention is to provide a method and an apparatus for manufacturing a liquid crystal component, which can form the optical resin layer in a surely desirable shape between the panel surface of the liquid crystal module and the transparent cover, in order to satisfy a further demand in a technology concerning the optical resin which has been recently developed and disclosed.
To achieve the above-described object, a method for manufacturing a liquid crystal component according to the present invention is a method for manufacturing a liquid crystal component, wherein a transparent cover is provided with a gap relative to a panel surface of a liquid crystal module, and after filling the gap with a transparent resin, the resin is cured to bond the liquid crystal module and the transparent cover, characterized in that a dam is formed by semi-curing the resin after applying the resin to a peripheral section of at least one surface of the panel surface and a surface of the transparent cover facing the panel surface, the panel surface and the transparent cover are faced after applying the resin to a center section of at least one surface of the panel surface and the transparent cover surface facing the panel surface, the resin applied to the center section is pushed to spread by reducing the gap between the panel surface and the transparent cover facing each other, and a whole of the resin which exists in the gap is cured after the resin pushed to spread is dammed up by the dam.
In that method, because the semi-cured dam is formed after applying the resin to the peripheral section of at least one surface of the panel surface and the surface of the transparent cover facing the panel surface, when the resin applied to the center section is pushed to spread in the gap between the panel surface and the transparent cover, the resin which has been pushed to spread can be properly dammed by the dam so as to surely prevent an unnecessary protrusion into a position of a peripheral member. Because the liquid resin dammed by the dam is the same resin as the semi-cured resin which has formed the dam and both of them are in a condition before a complete cure, both resins can be easily assimilated into a single resin layer, without forming any interfacial surface therebetween. In addition, because of the damming by the dam a resin layer shaped in a predetermined planer shape can be easily formed by merely pushing to spread the resin. Furthermore, by pushing to spread the resin equally, the air entrainment can be easily prevented. As a result, a transparent resin layer is surely formed in a desirable shape in the above-described gap.
In the method for manufacturing a liquid crystal component according to the present invention, it is preferred that while the transparent cover surface facing to the panel surface is directed upward the resin is applied to the center section of the facing surface in a condition where the transparent cover is turned upside down, the resin applied as described above is hung down so that a more central part thereof is positioned at a lower part, and at that condition, the panel surface and the transparent cover are faced and the gap therebetween is reduced. The transparent cover with the resin which has been applied to the center section of its upper surface is turned upside down, in order that the applied resin comes to form a smooth curved shape where the more central part thereof is positioned at the lower part by the resin's own weight, and in that condition the air can be pushed out from the center section of the applied resin toward the periphery by pushing to spread the resin in reducing the gap between the panel surface and the transparent cover, so as to more surely prevent the air entrainment in achieving the pushing to spread the resin equally.
In this case it is preferable that an appropriate waiting time is given for the resin to hang down from a time when the transparent cover is turned upside down to a time when the gap is reduced. When an appropriate waiting time is given, even when it may be short, the curving surface of the hanging resin becomes smoother curving surface, so that the air entrainment can be surely prevented in achieving pushing more uniformly to spread the resin.
In addition, it is also preferable that a pressurization of the transparent cover toward the panel surface of the liquid crystal module is controlled when the above-described gap is reduced. Because the pressurization control makes it possible to control a velocity of pushing to spread the resin or an amount of pushing to spread it, a control of an arrival time to the dam of the resin to be pushed to spread becomes possible as well as a control toward a desirable shape of a combined shape of the resin which has been pushed to spread and the resin which has formed the dam. In this pressurization control a feed back control can be performed by detecting the pressure so that the pressure becomes a target pressure. In addition, if the sensor is provided in each corner part and a pressure detected by each sensor is controlled to become equal, the pressure distribution can be equalized.
In addition, it is preferable that a parallelism of the transparent cover relative to the panel surface of the liquid crystal module is adjusted when the gap is reduced. If the parallelism is adjusted in a predetermined range, the resin to be pushed to spread can extend more equally. In addition, the air becomes easy to get out to the periphery so that the air entrainment can be prevented more surely. This parallelism can be achieved by either adjusting an inclination of support means at the time of bonding or equalizing a gap (or a position such as a height of a bonding object member) detected by each sensor provided in each corner part to a predetermined value.
In addition, it is preferable that when the panel surface and the transparent cover are faced to each other, a position adjustment, namely an alignment, between them is performed. From the aspect of the process simplification it is preferable that the dam is formed at only one side of the panel surface and the transparent cover, and when both of them are aligned in a predetermined relationship, even a positional relationship between the resin applied to the center section and the dam can be determined into a desirable positional relationship, and the pushing to spread the resin and the damming by the dam can be performed in more desirable form in the present invention.
The dam can be formed by a dispenser which applies the resin on a predetermined part in sequence, or by a stamper which applies the resin at once in a predetermined form. They can be selected appropriately in consideration of the apparatus specification or demanded takt time, etc.
In the method using the stamper, when a desirable resin layer is formed in the gap between the panel surface of the liquid crystal module and the surface of the transparent cover facing the panel surface, first the resin to fill the gap is applied using the stamper on at least one surface of either the panel surface of the liquid crystal module or the surface of the transparent cover facing the panel surface. Because the stamper keeps the resin in a predetermined pattern, when the kept resin is simply transcribed the resin can be applied at once, namely in an extremely short time, in a desirable pattern, namely the pattern which is optimum for forming the resin layer, and therefore the takt time of a whole bonding process can be greatly reduced. In addition, because this optimum pattern to keep the resin is set in a predetermined pattern as the most desirable pattern by a preliminary experiment, etc., the optimum pattern to apply the resin can be surely reproduced in the everytime resin application, being extremely suitable to achieve a mass production. The resin to form the dam is applied in the optimum pattern, so that the pushing to spread the resin after its application can be performed smoothly in a desirable form.
In a method according to the present invention, the dam can be formed all over a whole circumference of the peripheral section of the above-described one surface, as to a planar shape of the dam to be formed. In this case, it is preferable to form a comparatively short dam relative to the size of the above-described gap in order that the air can be easily let out. In addition, the dam can also be formed intermittently in the peripheral section of the above-described one surface. In this case, because the space between adjacent dams formed intermittently can function as an outlet of the escaping air, the dam can be formed into a comparatively high dam having a high damming function against the resin which has been pushed to spread.
As the above-described transparent resin, an ultraviolet cure resin is preferably used because it is available actually and has been verified for its target optical function like the optical resin disclosed in non-patent document 1 as described above has been an ultraviolet cure resin, though even a thermosetting resin could be used in principle.
Further, the following embodiment can be employed in the method for manufacturing a liquid crystal component according to the present invention. In other words, after applying the resin to fill the gap to at least one surface of the panel surface of the liquid crystal module and the transparent cover surface facing the panel surface, a total weight of the applied resin and an object to be applied is scaled, a weight of the applied resin only is determined by subtracting a weight of the object to be applied from the total weight, a size of the gap to be controlled is calculated from the weight of the applied resin and a predetermined area to be filled with the resin in the gap, and based on the calculated size of the gap, a relative position of the transparent cover surface facing the panel surface to the panel surface of the liquid crystal module can be controlled.
In this method, the total weight of the applied resin and the object to be applied is scaled, and the weight of the applied resin only, is determined by subtracting the weight, which has been grasped in advance or which has been preliminarily scaled before the resin application, of the object to be applied from the total weight, and the size of the gap to be controlled is calculated based on a relation between the weight of the applied resin and the predetermined area (namely, the area which is supposed to be filled with the resin and which is so determined as to be able to prevent the reflection or the light scattering on a conventional interfacial surface as described above and to improve greatly the brightness or the contrast ratio from the display of the liquid crystal panel) to be filled with the resin in the gap. By controlling the relative position (namely, the final gap size to bond both of them) of the transparent cover surface facing the panel surface to the panel surface of the liquid crystal module into this calculated gap size (namely, by reducing the actual gap into the above-described calculated size of the gap), the interposed applied resin can be pushed to spread all over the whole desired region, causing no protrusion from the region. As a result, the control into the optimum gap can be achieved in accordance with the amount of the applied resin, and the whole region of the optimum gap can be filled with the resin without protrusion. Further, because the gap size as a control target has been calculated before the start of the pushing movement to spread the resin by reducing the gap actually, when the relative position of the transparent cover surface facing the panel surface to the panel surface of the liquid crystal module is controlled (for example, the height position of the transparent cover surface facing the panel surface relative to the panel surface of the liquid crystal module), the target position can be controlled at high speed and the takt time of the whole bonding process can be shorten.
Furthermore, the following embodiment can be employed in the method for manufacturing a liquid crystal component according to the present invention. In other words, before a whole of the resin which exists in the gap is cured, a light irradiated from a side direction toward a layer of the resin, and a presence of a bubble in the layer of the resin can be detected by an observation means, utilizing a difference in refractive index with respect to the irradiated light.
In this method, when the interposed resin between the panel surface of the liquid crystal module and the facing surface of the transparent cover, which are facing each other, is pushed to spread by reducing the gap, if the air entrainment is generated and an air bubble comes in the resin layer, the presence of the air bubble in the resin layer is detected by the observation means, utilizing a difference in refractive index with respect to the light irradiated from the side direction. Because the difference in refractive index is utilized and the interfacial surface between the air bubble and the resin can be recognized clearly, even a minimal air bubble can be detected in a high precision. As the observation means, CCD camera, etc. is preferably used because there is a fear that the number of the pixels may run short in the image processing.
The presence of the air bubble in the resin layer is detected in a high precision, so that a desirable resin layer is formed and the resin can be cured only for a bonded body reaching an acceptability criterion, on the other hand, a bonded body which has failed to reach the acceptability criterion can be easily applied to a repair treatment because the resin has not been full-cured. Therefore, an extremely high rate of the process yield can be surely achieved. In addition, because the presence of the air entrainment generation can be detected properly by simple means the bonding process can be performed effectively, which makes a contribution to the reduction of the takt time of the whole bonding process.
An apparatus for manufacturing a liquid crystal component according to the present invention is an apparatus for manufacturing a liquid crystal component, wherein a transparent cover is provided with a gap relative to a panel surface of a liquid crystal module, and after filling the gap with a transparent resin, the resin is cured to bond the liquid crystal module and the transparent cover, comprising:
means for applying the resin to a peripheral section of at least one surface of the panel surface and a surface of the transparent cover facing the panel surface, in a shape of a dam,
means for semi-curing the resin applied in the dam shape,
means for applying the resin in a center section of at least one surface of the panel surface and the transparent cover surface facing the panel surface,
means for making the panel surface and the transparent cover face each other,
means for pushing to spread the resin applied in the center section by reducing the gap between the panel surface and the transparent cover facing each other until the resin is dammed up by the dam, and
means for curing a whole of the resin which exists in the gap.
In the apparatus for manufacturing a liquid crystal component, it is preferable that the means for applying the resin in the center section of at least one surface of the panel surface and the transparent cover surface facing the panel surface comprises means for applying the resin in the center section of the facing surface while the transparent cover surface facing to the panel surface is directed upward, and the apparatus has means for turning the transparent cover upside down for making a condition where the applied resin is hung down so that a more central part thereof is positioned at a lower part.
In this case, it is preferable that a waiting time is given for the resin to hang down from a time when the transparent cover is turned upside down to a time when the gap is reduced.
In addition, it preferable to have means for controlling a pressurization of the transparent cover toward the panel surface of the liquid crystal module when the gap is reduced.
Further, it is also preferable to have means for adjusting a parallelism of the transparent cover relative to the panel surface of the liquid crystal module when the gap is reduced.
Further, it is preferable to have means for adjusting a position (means for aligning) between the panel surface and the transparent cover.
In addition, a structure which has either a dispenser or a stamper for applying the resin to form the dam can be employed.
The dam can be formed in a whole circumference of the peripheral section of the one surface, and can be formed intermittently.
Further, it is preferable that an ultraviolet cure resin is used as the transparent resin, and in that case it is preferable to have an ultraviolet irradiating means for semi-curing and curing the ultraviolet cure resin.
According to the method and the apparatus for manufacturing a liquid crystal component according to the present invention, as for the technology concerning the optical resin which has been recently developed and disclosed, the optical resin layer can be formed in a surely desirable shape between the panel surface of the liquid crystal module and the transparent cover with no unnecessary protrusion. That makes it possible to correspond with a mass production utilizing this optical resin.
Hereinafter, desirable embodiments of the present invention will be explained referring to figures.
XY biaxial table 12 whose position can be controlled in horizontal directions X,Y, for example provided with an NC (numerical control) servomechanism;
XY biaxial table 13 thereon whose position can be controlled in horizontal directions X,Y, for example provided with an air cylinder;
bonding/inversion table 14 provided on XY biaxial table 13;
bonding/inversion pedestal 15 provided on bonding/inversion table 14;
post-inversion loading pedestal 17 having pin 16, loading pedestal for repair stock 18 and;
bonding mechanism 19 whose position can be controlled in a vertical direction Z and whose pressurizing power can be controlled at the time of bonding. Bonding mechanism 19 is provided with the followings: dispenser 20,21 for applying the optical resin made of a transparent ultraviolet cure resin attached with an elevator cylinder having a large diameter and a small diameter; observation camera 22, such as CCD camera whose view angle is a predetermined value, attached with an elevator cylinder and; ultraviolet irradiation means 23 (ultraviolet light source) to irradiate ultraviolet (UV) for semi-curing or curing (for example, the above-described pre-curing) the applied resin.
Hereinafter, the operation of thus constructed apparatus will be explained together with an example of the method according to the present invention. As depicted in
Next as depicted in
Next as depicted in
Next as depicted in
Next as depicted in
After the completion of a predetermined bonding, as depicted in
In the above-described successive steps, though a planar shape of a dam to apply to transparent cover 31 is not limited, it can be formed in a shape depicted in
In addition, as depicted in
The forming of the target resin layer can be achieved as depicted in
The above-described measurement of the total weight can be performed by a weight sensor provided in the apparatus such as a weight sensor provided in a holding means of the transparent cover. The calculation of the applied resin itself may be executed by a computer based on the signal from the weight sensor, and the target gap may be calculated by a computer from the obtained weight of the applied resin and the predetermined gap area.
By adding such a step S11, the gap size as a control target can be calculated before the operation that the gap is actually reduced and the resin is pushed to spread, and at the time of controlling the relative position of the transparent cover surface facing to the panel surface relative to the panel surface of the liquid crystal module, the control into the target position can be performed at a high speed so that the takt time of the whole bonding process can be shorten.
In the inspection of the air entrainment, for example, observation camera 22 such as the above-described CCD camera is used and the alignment height of camera 22 is adjusted to the resin layer between transparent cover 31 and substrate 35 by adjusting the height of bonding mechanism 19, so that the air bubble presence in the resin layer can be detected, as depicted in
The method and the apparatus for manufacturing a liquid crystal component according to the present invention is applicable for all uses to bond both of the panel surface of the liquid crystal module and the transparent cover by filling the gap therebetween with a predetermined resin, and specifically suitable for the use required to see the display under the sunlight, for example for a manufacturing of a liquid crystal module of cellular phones.
Number | Date | Country | Kind |
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2007-169454 | Jun 2007 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2008/061194 | 6/19/2008 | WO | 00 | 1/11/2010 |