Patent Application
20090167979
1. Field of the Invention
The present invention relates to a structure of a liquid crystal display panel carrying an image display portion of a liquid crystal display apparatus, further in details, relates to a structure of assembling a liquid crystal display panel capable of being assembled simply and at low cost.
2. Prior Art
A liquid crystal display apparatus is constituted by installing various kinds of boards, a speaker, and a liquid crystal display panel or the like to an inner portion of a display portion constituted by a back face side cabinet and a front face side cabinet. Further, the liquid crystal display panel is constituted by a structure of successively attaching an outer shape part of covering upper and lower, left and right, and back faces of a light emitting part, an optical sheet of diffusing/converging light irradiated by the light emitting part, and a liquid crystal cell of displaying an image to a front face side of the light emitting part. Further, as the light emitting part, one constituted by arranging a cold cathode fluorescent tube substantially in a linear shape, or a plurality of LEDs is used to constitute a structure of holding a vicinity of an end portion of the light emitting part by the outer shape part.
The optical sheet and the liquid crystal cell are attached to the outer shape part by using holding members of respectively holding vicinities of edge portions thereof and means for supplying a power source is constituted by being connected to the light emitting part and a circuit board installed to an inner portion of a cabinet of the liquid crystal display apparatus by way of a wire member. Further, the liquid crystal cell is connected to a drive circuit board separately by way of a flexible printed wiring plate, and the drive circuit board is fixed to the liquid crystal display panel and connected to a control circuit board separately installed to the liquid crystal display apparatus. Further, there is also a liquid crystal display apparatus in which a circuit of supplying a power source and a control circuit are constituted by the same board.
Describing a structure of a holding member mentioned above in details, there is “method of fabricating display apparatus and face-like member” according to JP-A-2006-317865. According to the structure, although a liquid crystal cell can be prevented from being destructed by constituting a front bezel (holding member) of holding the liquid crystal cell by a frame member in a quadrangular shape, the front bezel constituted by the frame member in the quadrangular shape is constituted by punching and forming a flat plate, and therefore, a material of a center portion is wasted, and therefore, high cost is caused.
Further, in “liquid crystal module” according to JP-A-2006-350218, a loss of a material in fabricating is restrained by dividing a bezel (holding member) in a shape of a rectangular frame into two members, and the bezel is constituted by forming the two members into a rectangular frame shape by carrying out an operation of fastening two members into the frame by a screw. Hence, there are provided a liquid crystal panel (liquid crystal cell), a bezel in a shape of a rectangular frame (holding member for liquid crystal cell), a frame, a linear light source (light emitting part) for a back light, a reflecting sheet, and a back face plate. The bezel is divided into two members in an L-like shape, and respective divided ends of the respective members are provided with projected pieces of forming screw fastening pieces by being overlapped by each other. The two members are installed into the frame in the rectangular shape by fastening the screw fastening pieces to the frame by setscrews to form the bezel in a shape of the rectangular frame. That is, despite an L type mode of dividing the frame-like bezel in two, a molding die is complicated and large-sized, and when a size thereof is increased, the bezel is frequently deformed by being bent in transportation or in installation.
Further, in “frame structure used in back light module” according to JP-A-2006-285161, a middle frame (holding member for optical sheet) constituting the structure is constituted by a frame member in a quadrangular shape, an edge of an optical sheet mounted on a back chassis is held, and a liquid crystal cell is held by a front bezel (holding member for liquid crystal cell) by mounting a surrounding edge of the liquid crystal cell on the middle frame. Therefore, cost is increased and molding die is enlarged similar to the above-described structure.
The holding member constituting the liquid crystal display panel of the background art poses the above-described problem in this way. A problem to be resolved by the invention is constituted by the problem and the invention provides a liquid crystal display panel including a holding member fabrication of which is simple at low cost. Further, the invention provides a liquid crystal display panel alleviating color nonuniformity based on a difference of colors of the holding member and an outer shape part and preventing leakage of light to outside.
A liquid crystal display panel according to the invention is constituted by a structure of arranging a back face member on a rear side of a light emitting part, further, arranging side face members on both sides of the light emitting part, constituting an outer shape part by the back face member and the side face member, arranging the light emiting part on a side of an inner face of the outer shape part, and successively installing an optical sheet, a middle holding member of holding the optical sheet, a liquid crystal cell of displaying an image, and a front face side holding member of holding the liquid crystal cell on a front face side of the light emitting part. The back face member is constituted substantially by a trapezoidal shape in a sectional view thereof extending edge portions of two sides different from a side of attaching the side face member, and the side face member is constituted by a shape matching with the sectional shape of the back face member. Further, the liquid crystal display panel is constituted by a structure of including first holding means for holding vicinities of edge portions of two sides opposed to each other of the optical sheet at the side face member, including second holding means for holding a vicinity of an edge portion of other one side of the optical sheet at the back face member and holding a vicinity of an edge portion of a side opposed to the side of the optical sheet held by the second holding means by the middle holding member. Therefore, the optical sheet is easily attached to the outer shape part by the first holding means, the second holding means, and the middle holding member. Further, there may be constituted a structure of holding other two sides different from the two sides of the optical sheet held by the first holding means by the middle holding member.
Describing in details of the structure of holding the vicinity of the edge portion of the optical sheet by the middle holding member, it is preferable to form a single or a plurality of locking hook(s) at the middle holding member, forming a flat receiving face for mounting the optical sheet at a position of the back face member for attaching the middle holding member, and forming groove holes engaging with the formed locking hooks by a number the same as that of the locking hooks at the middle holding member. Further, it is further preferable to constitute a structure of extending both end portions of the middle holding member to overlap front face sides of the side face members contiguous to each other.
Further, describing in details of the structure of holding the vicinities of the edge portion of the optical sheet by the first holding member, it is preferable to constitute a structure of forming recess grooves on sides of inner faces opposed to each other of the side face members, forming projections fitted to the recess grooves to extend from both end edges of the optical sheet to outer sides, and holding the projections formed at the optical sheet to fit to the recess grooves formed at the side face members.
Further, describing in details of the structure of holding the vicinity of the edge portion of the optical sheet by the second holding member, it is preferable to constitute a structure of forming a foldback portion substantially in a channel-like shape in a section thereof at an end portion of the back face member and holding the vicinity by fitting the edge portion of the optical sheet to the foldback portion.
Further, when the optical part is a cold cathode fluorescent tube constituting substantially a linear shape or substantially a U-like shape, it is preferable to constitute a structure of holding both end portions of the cold cathode fluorescent tube by the side face members.
Further, the liquid crystal cell is attached after attaching the optical sheet to the outer shape part, and the liquid crystal cell is constituted by a structure of using the front face side holding member constituted by divided parts of respectively holding vicinities of respective sides thereof and pinching the vicinities of the respective sides of the liquid crystal cell by the respective front face side holding members along with the side face members, the back face member, or the middle holding member.
It is preferable for the front face side holding members to make the shapes of parts attached to positions symmetric with each other by constituting a reference by a center of the liquid crystal cell the same, further, it is preferable to provide the front face side holding member with fastening means with the back face member.
Further, the liquid crystal cell includes a drive circuit board connected from a vicinity of any one side by way of a flexible printed wiring plate constituting substantially a shape of a flat face, in order to prevent an erroneous operation of the drive circuit board by leakage of light of the light emitting part, it is preferable to form a drive circuit board fixing portion for fixing the drive circuit board to the back face member, construct a constitution for holding at least a vicinity of an edge portion of one side of the optical sheet the most proximate to the drive circuit board fixing portion by the middle holding member, and form a light blocking wall for preventing light of the light emitting part from being leaked to a side of the back face member at the middle holding member.
According to the liquid crystal display panel of the invention, with regard to holding the optical sheet at the outer shape part, there is constituted a structure of holding two sides, or three sides of the optical sheet by the first holding means, and the second holding means provided at the existing outer shape part, and holding remaining one side or two sides by the middle holding member, and therefore, in comparison with a middle frame (holding member for optical sheet) of the background art constituted by a frame member in a quadrangular shape, fabrication is simple and cost is inexpensive. Further, by constituting the front face side holding member of holding the liquid crystal cell by divided structures for respectively holding the respective sides of the liquid crystal cell, in comparison with a front bezel (holding member for liquid crystal cell) of the background art constituted by the frame member in a quadrangular shape, fabrication is easy and cost is inexpensive. Further, by making the shapes of the holding members on the front face side disposed at the positions respectively symmetric with each other by constituting the reference by the center of the liquid crystal cell the same, a die for molding can be simplified, a number of the dies can be reduced, and deformation of shape in transportation and installation can be prevented.
In addition thereto, when the front face side holding member is attached for holding the liquid crystal cell, first, by tacking two sides opposed to each other of the liquid crystal cell which are not connected with the drive circuit board by the front face side holding member, the liquid crystal cell can tackedly be fixed to the outer shape part, and in such a state, even when the liquid crystal display panel in the midst of an assembling operation is erected or reversed, the liquid crystal cell is not detached to drop from the outer shape part, and an operation of fixing the drive circuit board connected with the liquid crystal cell to the back face member can simply be carried out.
Further, by constituting the middle holding member by the structure of forming to extend both ends to overlap the front face side of the side face member, a color nonuniformity in displaying an image is prevented, further, by forming the light blocking wall at the middle holding member for holding the optical sheet, light leaked to the side of the back face member can be blocked, and the erroneous operation of the drive circuit board can be prevented.
An embodiment as the best mode for carrying out the invention will be explained as follows in reference to
According to the liquid crystal display apparatus, inner constitution parts of various kinds of boards, a speaker or the like are successively attached to the back face side cabinet 3, finally, the liquid crystal display panel 15 constituted by installing the respective parts shown in
That is, although when the liquid crystal display panel 15 is attached to the back face side cabinet 3, it is not easy to lead out the connector attached with wire member extended from the power source supplying circuit board to be processed to connect to the cold cathode fluorescent tube 7, according to the invention, by attaching the connector 17 to the side frame 8, an operation of connecting the power source supplying circuit board can be facilitated.
The back chassis 5 includes an upper side plate 19a and a lower side plate 19b on both sides (upper and lower sides) of a back plate 18 and the upper and lower side plates 19a and 19b are inclined in directions of opening front end sides thereof. That is, substantially a trapezoidal shape is constituted in a sectional view thereof. Further, an edge 20b of the lower side plate 19b is constituted by substantially a channel-like shape in a section thereof and lower ends of the diffusion plate 9 and the diffusion sheet 10 are fitted thereto to be attached to stop thereby. An edge 20a of the upper side plate 19a on one side is constituted by a flat receiving face and mounted with upper ends of the diffusion plate 9 and the diffusion sheet 10.
The reflecting sheet 6 is provided with a similar section one size smaller than that of the back chassis 5 and includes an upper side plate 22a and a lower side plate 22b on both sides of a back plate 21. Therefore, the back plate 21 overlaps the back plate 18, the upper side plate 22a overlaps the upper side plate 19a, and the lower side plate 22b overlaps the lower side plate 19b to laminate. Further, openings of both ends of the reflecting sheet 6 are installed with the side frames 8, 8 substantially in a trapezoidal shape, the side frames 8, 8 are attached with a plurality of pieces of the cold cathode fluorescent tubes 7, 7 . . . , and the connectors 17, 17 . . . connected with wire members 23, 23 . . . extended from one end sides of the cold cathode fluorescent tubes 7, 7 . . . are fitted to be attached to the connector holding portions 16, 16 . . . formed at the side frame 8. Further, although the reflecting sheet 6 is used in the embodiment in order to increase a brightness of light irradiated from the cold cathode fluorescent tubes 7, 7 . . . , the reflecting sheet 6 can also be saved by, for example, forming the back chassis 5 by color capable of increasing the brightness, or directly coating an inner face side of the back chassis 5 by color easy to be reflected.
The diffusion plate 9 and the diffusion sheet 10 are overlapped to be mounted, the lower ends of the diffusion plate 9 and the diffusion sheet 10 are inserted to the edge 20b of the section substantially in the channel-like shape of the lower side plate 19b of the back chassis 5 as described, and the upper edges are mounted on the flat receiving portion of the edge 20a of the upper side plate 19a. Further, both side ends of the diffusion plate 9 and the diffusion sheet 10 are mounted on upper faces of the side frames 8, 8, projections 24, 24 are formed to project at side ends of the diffusion plate 9 and the diffusion sheet 10, and the projections 24, 24 are fitted to recess grooves provided at the side frames 8, 8 to be attached to stop thereby.
Further, projections 25, 25 . . . formed at upper ends of the diffusion plate 9 and the diffusion sheet 10 are fitted to grooves provided at the edge 20a of the upper side plate 19a to be attached to stop thereby. In this way, the middle frame 11 is attached to upper end portions of the diffusion plate 9 and the diffusion sheet 10 mounted on the edges 20a, 20b of the back chassis 5 and the side frames 8, 8, and the slender rubber members 14, 14 . . . are attached to the side frames 8, 8, the edge 20b of the lower side plate 19b and the middle frame 11. Further, the liquid crystal cell 12 is laminated thereon and the front bezel 13 is attached thereto.
The front bezel 13 is constituted by 4 pieces of bezels of an upper bezel 13a, a lower bezel 13b, a left bezel 13c, and a right bezel 13d, the upper and the lower bezels 13a, 13b are constituted by a common shape, and also the left and the right bezels 13c, 13d are constituted by a common shape.
That is, the left and the right bezels 13c, 13d constitute an L shape section and includes a longitudinal piece 26 and an upper piece 27 and both side ends of the liquid crystal cell 12 are held by the upper pieces 27 by tacking the longitudinal pieces 26 to the side frames 8.
The middle frame 11 holds upper ends of the diffusion plate 9 and the diffusion sheet 10 mounted on the upper side plate edge 20a of the back chassis 5 and are attached to overlap the upper face of the side frame 8 by forming to extend an end portion thereof. Although the side frame 8 is molded by a resin of white color to reflect light, the middle frame 11 is constituted by black color to prevent leakage of light.
Hence, when both end portions of the middle frame 11 are brought into a state of being butted to inner side faces of the side frame 8, light is leaked from a gap between the middle frame 11 and the side frame 8, or a nonuniformity of color is brought about at a corner of the liquid crystal cell 12. Particularly, in a white screen display, a nonuniformity constituting a black shadow in an optically recognized range of the liquid crystal cell 12 is brought about to constitute a factor of considerably deteriorating a grade. In order to prevent this, the both end portions of the middle frame 11 are extended to bring about a state of being overlapped to the upper face of the side frame 8.
Meanwhile, in a state of locking the hook 37 of the middle frame 11 by the groove hole of the back chassis 5, a gap is produced between the hook 37 and the groove hole and light of the cold cathode fluorescent tubes 7, 7 . . . is leaked from a surrounding of a hole 38.
Meanwhile, although according to the embodiment, there is constituted a structure of attaching the middle frame 11 only at upper ends of the diffusion plate 9 and the diffusion sheet 10 to hold, the middle frame 11 can also be attached to lower ends thereof. Therefore, in this case, it is not necessary to constitute the lower side plate edge 20b of the back chassis 5 by the shape of the section substantially in the channel-like shape but similar to the edge 20a of the upper side plate 19a, a structure of forming a flat receiving portion and mounting the lower ends of the diffusion plate 9 and the diffusion sheet 10 is constituted. Further, the groove hole of locking the hook 37 of the middle frame 11 is provided.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-340815 | Dec 2007 | JP | national |
