Patent Application
20180329239
The present invention relates to a display apparatus that displays an image using a liquid crystal panel. The present invention also relates to a display apparatus that has a configuration including a curved liquid crystal panel and capable of maintaining a good display quality, and to a method for producing the display apparatus.
In the field of recent display apparatus, curved displays including curved liquid crystal panels have been in practice. Preventing defects due to separation, distortion, misalignment, and the like of and between components has been a challenge in production of such curved displays.
Patent Literature 1 discloses a production method of a curved display. According to this production method, an acrylic or polycarbonate front supporting substrate is first placed on a semi-cylindrically shaped support having a curved surface (such as a side surface of a cylindrical product), and the front supporting substrate is preliminarily curved along the curved surface of the support. Next, an adhesive layer is formed on the curved front supporting substrate, and a liquid crystal panel including glass substrates is placed on the adhesive layer. The liquid crystal panel is attached to the adhesive layer by a certain process such as roller compression bonding or vacuum compression bonding thereby to curve the liquid crystal panel. Patent Literature 1 further discloses the following. A back supporting substrate is placed on the liquid crystal panel and curved along the liquid crystal panel. The front supporting substrate and the back supporting substrate are screwed to each other so as to hold the liquid crystal panel therebetween thereby to retain the curved surface of the liquid crystal panel.
Japanese Patent Application Laid-Open Publication No. 2011-085740
A liquid crystal panel includes a glass substrate provided with thin film transistors (TFTs) and a glass substrate provided with color filters (CFs), which are bonded with a photocurable adhesive. The glass substrates are each bonded in a narrow bonding region along a perimeter thereof. Such a bonding region accounts for a smaller percentage of an overall substrate surface particularly in a larger display apparatus. In a liquid crystal panel that is curved alone, glass substrates easily exert force to stretch outward along a curved shape thereof. Besides, the two glass substrates may stretch non-uniformly due to a difference in curvature therebetween. In such a situation, the two glass substrates may become misaligned relative to each other.
Conventional production methods of curved displays including the method disclosed in Patent Literature 1 are to curve and thus deform components sequentially on a component-by-component basis. The invention disclosed in Patent Literature 1 successfully reduces an effect of stress that develops due to the curved liquid crystal panel returning toward flat, but fails to cope with force that is exerted on non-curved portions of the liquid crystal panel when the liquid crystal panel is curved and thus deformed in the production.
The present invention has been made in view of the circumstances described above, and an object thereof is to provide a display apparatus and a method for producing the display apparatus, according to which it is possible to suppress misalignment of substrates relative to each other in a liquid crystal panel therein due to force exerted when the liquid crystal panel is curved and thus deformed, and thereby to reduce defective display.
A display apparatus according to one embodiment of the present invention includes a curved liquid crystal panel and a transparent plate. The curved liquid crystal panel includes a pair of glass substrates arranged opposed to each other and a liquid crystal enclosed between the glass substrates. The transparent plate is disposed over one surface of the curved liquid crystal panel which faces inward of a curved shape thereof, is larger than the curved liquid crystal panel, and is curved along the curved liquid crystal panel.
The display apparatus according to the embodiment of the present invention further includes additional plates and adhesive layers. The additional plates are respectively disposed over two opposed edge sections on a liquid crystal panel-facing surface of the transparent plate and along edges of the transparent plate, with the curved liquid crystal panel between the transparent plate and the additional plates. The adhesive layers bond sections of the transparent plate to the additional plates. The sections are outside of a region corresponding to the curved liquid crystal panel.
In the display apparatus according to the embodiment of the present invention, the transparent plate is bonded to the one surface of the curved liquid crystal panel.
The display apparatus according to one embodiment of the present invention further includes an additional plate and adhesive layers. The additional plate is disposed over another surface of the curved liquid crystal panel which is opposite to the one surface, has substantially the same size as the transparent plate, and is curved along the curved liquid crystal panel. The adhesive layers bond sections of the transparent plate to the additional plate. The sections are outside of a region corresponding to the curved liquid crystal panel.
In the display apparatus according to the embodiment of the present invention, the transparent plate is more rigid than the curved liquid crystal panel.
A method for producing a display apparatus according to one embodiment of the present invention is a method for producing a display apparatus including a curved liquid crystal panel. The curved liquid crystal panel includes a pair of glass substrates arranged opposed to each other and a liquid crystal enclosed between the glass substrates. The method includes placing, fixing, and curving and thus deforming. In the placing, a liquid crystal panel yet to be curved is placed over a transparent plate larger than the liquid crystal panel. In the fixing, the transparent plate and the liquid crystal panel are fixed to each other. In the curving and thus deforming, the transparent plate and the liquid crystal panel are curved and thus deformed together so that the transparent plate is inside of a curved shape thereof.
According to the embodiment of the present invention, a transparent plate larger than a flat liquid crystal panel is disposed over one surface of the liquid crystal panel which faces inward of a curved shape thereof, and both the liquid crystal panel and the transparent plate are curved together. Drag of the transparent plate, which is curved together with the liquid crystal panel on the inside of the curved shape, restricts force exerted in a stretching direction of the liquid crystal panel upon curving and deforming.
According to the embodiment of the present invention, the transparent plate disposed over the one surface and two additional plates respectively bonded to two opposed edge sections of the transparent plate hold the liquid crystal panel therebetween, and the transparent plate, the additional plates, and the liquid crystal panel are integrated and curved together. Drag of the transparent plate, which is curved together with the liquid crystal panel on the inside of the curved shape, restricts the force exerted in the stretching direction of the liquid crystal panel upon curving and deforming, because the transparent plate functions as an assisting plate in curving and deforming. The force in the stretching direction is further restricted by the additional plates bonded to the edge sections, and force of the liquid crystal panel returning toward flat is also restricted by the additional plates.
According to the embodiment of the present invention, the transparent plate disposed over the one surface is bonded to the curved liquid crystal panel. Also in a configuration in which the transparent plate is bonded to the liquid crystal panel, drag of the transparent plate, which is curved together with the liquid crystal panel on the inside of the curved shape, restricts the force exerted in the stretching direction of the liquid crystal panel upon curving and deforming, because the liquid crystal panel is integrated with the transparent plate before curving and deforming.
According to the embodiment of the present invention, the transparent plate disposed over the one surface and an additional plate having substantially the same size as the transparent plate hold edge sections of the liquid crystal panel therebetween, and thus the transparent plate, the additional plate, and the liquid crystal panel are integrated and curved together. Drag of the transparent plate, which is curved together with the liquid crystal panel, restricts the force exerted in the stretching direction of the liquid crystal panel upon curving and deforming, because the transparent plate functions as an assisting plate in curving and deforming. The force in the stretching direction is further restricted by the additional plate bonded to the sections of the transparent plate, which are outside of the region corresponding to the liquid crystal panel, and force of the liquid crystal panel returning toward flat is also restricted by the additional plate.
According to the embodiment of the present invention, the liquid crystal panel, which is originally flat, is joined to the transparent plate, which functions as an assisting plate, before being curved and deformed. Drag of the transparent plate, which is curved together with the liquid crystal panel on the inside of the curved shape, restricts the force exerted in the stretching direction of the liquid crystal panel, because the transparent plate and the liquid crystal panel that have been joined are curved and thus deformed together. It is more preferable to form an assisting plate as an optical member using a transparent material and include the assisting plate as a component of the display apparatus than to use and later remove a plate functioning as an assisting plate.
According to the embodiment of the present invention, the force that is exerted in the stretching direction of the liquid crystal panel upon curving and deforming is restricted, and thus misalignment of the pair of glass substrates of the liquid crystal panel relative to each other is suppressed. It is therefore possible to maintain the display quality of the display apparatus.
The following describes embodiments of the present invention in detail based on the drawings. It is to be understood that the embodiments described below are merely examples and the present invention is not limited to configurations described below.
The liquid crystal panel 1 has a shape obtained by curving a flat rectangular plate in a long side direction thereof such that a display surface (near-side surface in
The transparent plate 2 is obtained by curving a flat rectangular elastic transparent plate, such as an acrylic flat plate, in a long side direction thereof. The transparent plate 2 is larger than the liquid crystal panel 1. Preferably, an optical member such as a brightness enhancement film (BEF) and a diffuser sheet, not shown, is provided between the transparent plate 2 and the liquid crystal panel 1. A diffuser layer may be formed over a substantially entire surface, except a portion along a perimeter, of the transparent plate 2 to further provide some functions of an optical sheet disposed at a back surface of the liquid crystal panel. The transparent plate 2 is thicker than the liquid crystal panel 1. This is because the transparent plate 2 is preferably more rigid than the liquid crystal panel 1. For example, the liquid crystal panel 1 has a thickness of approximately 1 mm, and the transparent plate 2 has a thickness of approximately 2 mm. The transparent plate 2 may have the same thickness as the liquid crystal panel 1 as long as the transparent plate 2 is designed to be rigid enough to withstand a curvature radius of a desired curve and to restrict the liquid crystal panel 1 from being wavy when curved.
The fixing members 31 and 32 are obtained by curving flat rectangular plates of the same material as a base material of the transparent plate 2 or of a material that is more rigid than the base material of the transparent plate 2. A length of the fixing members 31 and 32 in a long side direction thereof is substantially equal to a length of the transparent plate 2 in a short side direction thereof. A length of the fixing members 31 and 32 in a short side direction thereof is slightly longer than a half of a difference between a length of the liquid crystal panel 1 in the long side direction thereof and a length of the transparent plate 2 in the long side direction thereof. The fixing members 31 and 32 are respectively bonded through adhesive layers 41 and 42 such that one of long sides of each fixing member is along either of short sides of the transparent plate 2. In such an arrangement, each of the fixing members 31 and 32 overlaps the liquid crystal panel 1 in a portion including the other of the long sides. Preferably, the adhesive layers 41 and 42 are of a material that remains stretchable after curing.
The display apparatus has a configuration in which the light source is disposed facing the liquid crystal panel 1, the transparent plate 2, and the fixing members 31 and 32, which are curved as described above, so as to face the transparent plate 2, and the housing and the retaining member house and retain the liquid crystal panel 1, the transparent plate 2, the fixing members 31 and 32, and the light source. Preferably, the retaining member retains the components while keeping the liquid crystal panel 1 and the light source in positions with a predetermined distance therebetween, and the housing surrounds the liquid crystal panel 1 so as to cover a perimeter and expose a display region.
The following describes steps for curving and thus deforming the liquid crystal panel 1 illustrated in
(1) Integration of Liquid Crystal Panel 1 with Transparent Plate 2
In production of the display apparatus according to Embodiment 1, the liquid crystal panel 1 is first integrated with the transparent plate 2.
(2) Deformation
Next, the liquid crystal panel 1, the transparent plate 2, and the fixing members 31 and 32 integrated as described in (1) are curved and thus deformed together.
The following describes effects produced by curving and thus deforming the liquid crystal panel 1, the transparent plate 2, and the fixing members 31 and 32 together as described above. First, localized stress on the liquid crystal panel 1 can be avoided, because the rigid transparent plate 2 is used as a jig for the liquid crystal panel 1, which is less rigid as employing thin glass substrates for ease of curving. Furthermore, the display apparatus can be formed thinner using a fewer components than a display apparatus formed using and later removing a plate functioning as an assisting plate, because the transparent plate 2 has a function of diffusing light from the light source and is included in the display apparatus as a component.
Integration of the liquid crystal panel 1 with the transparent plate 2 further produces an effect of restricting force that is exerted on ends of the liquid crystal panel 1.
According to the configuration of Embodiment 1, as described above, the transparent plate 2 functions as an assisting plate in curving and deforming, so that localized stress on the liquid crystal panel 1 can be avoided when curving the thin liquid crystal panel 1. Furthermore, drag of the assisting plate restricts force that is exerted in the stretching direction of the liquid crystal panel 1 and that is exerted on the ends of the liquid crystal panel 1. Thus, misalignment of the CF substrate 11 and the TFT substrate 12 relative to each other in the liquid crystal panel 1 is prevented. It is therefore possible to maintain the display quality in the liquid crystal panel 1.
The transparent plate 2 according to Embodiment 2 is bonded to a back surface of the liquid crystal panel 1 through an adhesive layer 6. The adhesive layer 6 is formed from a rubber-based adhesive that turns or remains transparent and stretchable after curing. The adhesive layer 6 bonds the transparent plate 2 to a region along a perimeter of a TFT substrate 12 of the liquid crystal panel 1. Preferably, the adhesive layer 6 has a thickness approximately equal to that of the liquid crystal panel 1. For example, the adhesive layer 6 has a thickness of at least 1 mm in a configuration in which the liquid crystal panel 1 has a thickness of approximately 1 mm.
The display apparatus according to Embodiment 2 has a configuration in which the light source is disposed facing the liquid crystal panel 1 and the transparent plate 2, which are curved as described above, so as to face the transparent plate 2, and the housing and the retaining member house and retain the liquid crystal panel 1, the transparent plate 2, and the light source.
The following describes steps for curving and thus deforming the liquid crystal panel 1 according to Embodiment 2 illustrated in
(1) Integration of Liquid Crystal Panel 1 with Transparent Plate 2
Also in production of the display apparatus according to Embodiment 2, the liquid crystal panel 1 is first integrated with the transparent plate 2.
(2) Deformation
Next, the liquid crystal panel 1 and the transparent plate 2 integrated as described in (1) are curved and thus deformed together.
Also according to Embodiment 2, the liquid crystal panel 1 and the transparent plate 2 that are integrated are curved and thus deformed together. Since the rigid transparent plate 2 is used as a jig, localized stress on the liquid crystal panel 1 can be avoided. Furthermore, the transparent plate 2 functions as an assisting plate in curving and deforming, and drag of the assisting plate restricts force that is exerted in the stretching direction of the liquid crystal panel 1 and that is exerted on the ends of the liquid crystal panel 1. Thus, misalignment of the CF substrate 11 and the TFT substrate 12 relative to each other in the liquid crystal panel 1 is prevented. It is therefore possible to maintain the display quality in the liquid crystal panel 1.
The transparent plates 21 and 22 are obtained by curving flat transparent rectangular plates in a long side direction thereof. The transparent plates 21 and 22 have substantially the same size as each other and are larger than the liquid crystal panel 1. The transparent plate 21 is for example composed of a highly transparent polymeric material such as poly(methyl methacrylate) (PMMA). The transparent plate 22 also provides some functions of an optical sheet as described below, and therefore may be formed as a diffuser plate by for example dispersing particles having different refractive indices in the polymeric material. The transparent plate 22 may also be formed so as to function as a light guide plate included in a light source. The transparent plates 21 and 22 are thicker than the liquid crystal panel 1. This is because the transparent plates 21 and 22 are preferably more rigid than the liquid crystal panel 1. For example, the liquid crystal panel 1 has a thickness of approximately 1 mm, and the transparent plates 21 and 22 have a thickness of approximately 0.5 to 2 mm. The transparent plates 21 and 22 may have the same thickness as the liquid crystal panel 1 as long as the transparent plates 21 and 22 are designed to be rigid enough to withstand a curvature radius of a desired curve and to restrict the liquid crystal panel 1 from being wavy when curved.
The transparent plates 21 and 22 are arranged with the liquid crystal panel 1 therebetween, and sections of the transparent plates 21 and 22, which are outside of the liquid crystal panel 1, are bonded through adhesive layers 43 and 44. In such an arrangement, a display surface of the liquid crystal panel 1 faces the transparent plate 21. The liquid crystal panel 1 is held between the transparent plates 21 and 22. Preferably, a BEF is disposed between a TFT substrate 12 of the liquid crystal panel 1 and the transparent plate 22.
The display apparatus according to Embodiment 3 has a configuration in which the light source is disposed facing the liquid crystal panel 1 and the transparent plates 21 and 22, which are curved as described above, so as to face the transparent plate 22, and the housing and the retaining member house and retain the liquid crystal panel 1, the transparent plates 21 and 22, and the light source. Preferably, the retaining member retains the components while keeping the liquid crystal panel 1 and the light source in positions with a predetermined distance therebetween, and the housing surrounds the liquid crystal panel 1 so as to cover a perimeter and expose a display region.
The following describes steps for curving and thus deforming the liquid crystal panel 1 illustrated in
(1) Integration of Liquid Crystal Panel 1 with Transparent Plates 21 and 22
(2) Deformation
Next, the liquid crystal panel 1 and the transparent plates 21 and 22 integrated as described in (1) are curved and thus deformed together.
Also according to Embodiment 3, the liquid crystal panel 1 and the transparent plates 21 and 22 that are integrated are curved and thus deformed together. Since the transparent plates 21 and 22 function as assisting plates in curving and deforming, localized stress on the liquid crystal panel 1 can be avoided while curving the thin liquid crystal panel 1. Furthermore, drag of the assisting plates restricts force that is exerted in the stretching direction of the liquid crystal panel 1 and that is exerted on the ends of the liquid crystal panel 1. Furthermore, according to Embodiment 3, the transparent plate 21 restricts opposed short side sections of the liquid crystal panel 1 from separating from the transparent plate 22 due to force of the liquid crystal panel 1 returning toward flat. Thus, misalignment of the CF substrate 11 and the TFT substrate 12 relative to each other in the liquid crystal panel 1 is restricted. It is therefore possible to maintain the display quality in the liquid crystal panel 1.
According to Embodiments 1 to 3, the liquid crystal panel 1 is curved in the long side direction thereof such that the display surface of the liquid crystal panel 1 is a convex. However, the present invention is not limited thereto, and the liquid crystal panel 1 may be curved such that the display surface thereof is a concave, or the liquid crystal panel 1 may be curved in a short side direction thereof.
Note that the presently disclosed embodiments are merely examples in all aspects and should not be construed to be limiting. The scope of the present invention is indicated by the claims, rather than by the description given above, and includes all variations that are equivalent in meaning and scope to the claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/082613 | 11/19/2015 | WO | 00 |
