The present invention relates to an illuminating device, a display device, and a television receiver.
For example, a liquid crystal panel that is used in liquid crystal display devices such as a liquid crystal television does not emit light by itself, and it is therefore necessary to separately provide a backlight device as an illuminating device. The backlight device is configured to be placed on the backside (side opposite to s display surface) of the liquid crystal panel. The backlight device includes a metal or resin chassis in which a surface on the liquid crystal panel side is opened, a reflecting sheet laid on a chassis, a plurality of fluorescent tubes (such as cold-cathode tubes) that are accommodated as the lamp in the chassis, a plurality of optical members (such as diffuser sheets) that are disposed in the opening portion of the chassis to efficiently send the light emitted from the cold-cathode tube onto the liquid crystal panel side, and a lamp clip that supports a middle portion of the elongated cold-cathode tube. The lamp clip has a configuration in which a lamp gripping portion that grips the cold-cathode tube is provided in a plate-like main body mounted on a bottom plate of the chassis.
When the cold-cathode tube is lit, a slight decrease in light quantity of the cold-cathode tube is inevitable in the lamp gripping portion. As a result, there is a risk of observing part of the main body as a faint shadow on the liquid crystal panel.
For example, Patent Document 1 proposes a technology of preventing the generation of the shadow in the main body. In the technology proposed in Patent Document 1, the main body is formed into a triangular shape in section, and an inclined surface is formed in a surface of the main body, and the light with which the main body is illuminated from both sides of the portion of the cold-cathode tube griped by the lamp gripping portion can be reflected toward the liquid crystal panel by the inclined surface. Therefore, the generation of the shadow is prevented in the main body.
Patent Document 1: Japanese Patent Publication Laid-Open No. 2005-17691
In the technology described in Patent Document 1, the generation of the shadow is prevented in the main body by devising the shape of the lamp clip. However, it is necessary to newly produce a lamp clip having a particular structure, and it is necessary to replace a general-purpose product conventionally used with the new lamp clip. This results in a problem of cost increase. Therefore, there is a demand for proposing another solving means as the solving means for suppressing the shadow of the main body, that is, luminance unevenness.
On the other hand, since the luminance unevenness is possibly generated by a difference in reflection efficiency between the lamp clip and the reflecting sheet, the problem of the generation of the luminance unevenness is hardly solved by the technology described in Patent Document 1. That is, there is a risk that the technology described in Patent Document 1 might be insufficient as the countermeasure for the luminance unevenness.
Specifically, in recent years, the demand for the thinner liquid crystal display device arises. When the backlight device is thinned in response to the demand, the luminance unevenness is easily generated by the reason such as a distance between the optical member and the cold-cathode tube is shortened. Therefore, the advanced countermeasure for the luminance unevenness tends to be required.
The above-described problem similarly occurs in the backlight device that includes an optical member support having a configuration in which a support pin is provided in the main body in order to support the optical member.
The present invention has been accomplished in view of the foregoing, and an object of the invention is to preferably reduce the luminance unevenness.
An illuminating device according to the present invention includes a chassis, a lamp disposed in the chassis, a lamp holder mounted to the chassis and a reflecting member disposed in the chassis. The lamp holder includes a main body and a lamp gripping portion. The lamp gripping portion is provided on the main body so as to grip the lamp. The reflecting member has an opening through which the lamp gripping portion is passed and an inner edge portion thereof covers an outer edge portion of the main body.
The lamp gripping portion that grips the lamp, the lamp gripping portion being included in the lamp holder, is passed through the opening of the reflecting member, and the outer edge portion of the main body is covered with the inner edge portion of the opening, which hardly visually recognizes as the shadow the outer edge portion of the main body that forms the step between the outer edge portion and the chassis. In the present invention, the reflecting member reduces the generation of the shadow in the outer edge portion of the main body, thereby enabling the use of the general-purpose product as the lamp holder to achieve the cost reduction. Additionally, because the lamp holder is covered with the reflecting member, the ratio of the surface area of the lamp holder to the surface area of the reflecting member is decreased. As a consequence, the luminance unevenness is hardly generated even if the lamp holder differs from the reflecting member in the reflection efficiency. Therefore, this configuration is suitable to the thinner liquid crystal display panel. As used herein, the “surface area” means an area of a portion in which the reflecting member or the lamp holder is exposed to the lamp.
A first embodiment of the invention will be described with reference to
As illustrated in
The liquid crystal panel 11 and the backlight device 12, which constitute the liquid crystal display device 10, will be described below (see
In a configuration of the liquid crystal panel (display panel) 11, a pair of glass substrates is bonded with a given gap, and liquid crystal is sealed between the glass substrates. One of the glass substrates is provided with switching elements (for example, TFT) connected to source interconnections and gate interconnections, which are orthogonal to each other, pixel electrodes connected to the switching elements, an oriented film, and the like. The other glass substrate is provided with a color filter in which colored portions such as R (red), G (green), and B (blue) are arrayed into a given matrix shape, a counter electrode, an oriented film, and the like. Polarizing plates 11a and 11b are disposed outside the substrates (see
As illustrated in
The chassis 14 is made of metal and formed into a shallow substantially box shape through sheet-metal processing. The chassis 14 includes a rectangular bottom plate and a folded outer edge portion (a folded outer edge portion 21a in a short-side direction and a folded outer edge portion 21b in a long-side direction) that is vertically folded into a substantially U-shape from each side. A plurality of mounting holes 22 are made in both end portions in a long-side direction of a bottom plate of the chassis 14 to mount the relay connectors 19. As illustrated in
A reflecting sheet 23 is provided on an inner surface side (the side of the surface opposite to the cold-cathode tube 17 or the diffuser plate 15a, surface side) of the bottom plate of the chassis 14. The reflecting sheet 23 is made of a synthetic resin, the surface of the reflecting sheet 23 is colored in white that is excellent in reflectivity, and the reflecting sheet 23 has a rectangular shape as the chassis 14 and is spread along the inside of the bottom plate surface of the chassis 14 so as to cover the substantially whole area of the bottom plate surface. The reflecting sheet 23 constitutes a reflecting plane that reflects the light emitted from the cold-cathode tube 17 in the chassis 14 toward the side of the diffuser plate 15a. As illustrated in
The cold-cathode tube 17 is formed into an elongated tubular shape. A plurality of the cold-cathode tubes 17 are in parallel with one another to be accommodated in the chassis 14 while length directions (axial direction) of the cold-cathode tubes 17 are aligned with the long-side direction of the chassis 14 (see
The holder 20 is made of a white synthetic resin. The holder 20 covers the end portion of the cold-cathode tube 17 and has an elongated substantially box shape extending along the short-side direction of the chassis 14. As illustrated in
The stepwise surface of the holder 20 includes three surfaces that are parallel to the bottom plate surface of the chassis 14, and the short-side edge portion of the diffuser plate 15a is placed on a first surface 20a that is located at the lowest position. An inclined cover 26 that is inclined toward the bottom plate surface of the chassis 14 extends from the first surface 20a. The short-side edge portion of the liquid crystal panel 11 is placed on a second surface 20b in the stepwise surface of the holder 20. A third surface 20c that is located at the highest position in the stepwise surface of the holder 20 is provided at a position at which the third surface 20c overlaps the folded outer edge portion 21a of the chassis 14, and the third surface 20c is in contact with the bezel 13.
The diffuser plate 15a is formed by a synthetic-resin plate-like member in which light scattering particles are blended in a dispersed manner. The diffuser plate 15a has a function of diffusing linear light emitted from the cold-cathode tube 17 that is of the tubular light source. As described above, the short-side edge portion of the diffuser plate 15a is placed on the first surface 20a of the holder 20, is not subjected to a constraint force in a vertical direction. On the other hand, as illustrated in
In the optical sheet 15b disposed on the diffuser plate 15a is constituted such that a diffuser sheet, a lens sheet, and a reflection type polarizing plate are sequentially stacked from the side of the diffuser plate 15a. The optical sheet 15b has a function of shaping the light, which is emitted from the cold-cathode tube 17 to pass through the diffuser plate 15a, into planar light. The liquid crystal panel 11 is placed on the upper surface side of the optical sheet 15b, and the optical sheet 15b is retained while sandwiched between the diffuser plate 15a and the liquid crystal panel 11.
The lamp clip 18 will be described in detail. The lamp clip 18 is made of a synthetic resin (for example, polycarbonate), and the surface of the lamp clip 18 is colored in white that is excellent in reflectivity. As illustrated in
A lamp gripping portion 28 that holds the cold-cathode tube 17 at a predetermined height and a support pin 29 that supports the diffuser plate 15a at a position higher than that of the cold-cathode tube 17 are provided on a front surface (surface opposite to the diffuser plate 15a and cold-cathode tube 17, the surface on the side opposite from the chassis 14 side) of the main body 27 as shown in
As illustrated in
Each two lamp clips 18 (lamp clips 18 disposed on both the end sides in the short-side direction with respect to the central side) arrayed in the long-side directions of the chassis 14 are disposed at positions that deviate in the long-side direction with respect to the lamp clips 18 adjacent to each other in the short-side direction. Accordingly, compared with the case in which the lamp clips 18 are arrayed in line along the short-side direction, a shadow of the lamp clip 18 is hardly visible from a human eye characteristic because the lamp clips 18 are disposed in the dispersed manner in the bottom plate surface of the reflecting sheet 23. Assuming that the number of lamp clips 18 are equal, it is easily visible from the human eye characteristic when the lamp clips 18 is disposed linearly or collectively, while the luminance unevenness is hardly generated in the backlight device 12 by disposing the lamp clips 18 in the dispersed manner like the present embodiment even if the reflecting sheet 23 differs from the lamp clip 18 in reflectance.
As described above, although the lamp clips 18 are disposed in the dispersed manner to some extent in the chassis 14, the existing range of the lamp clips 18 is limited to the specific range in the long-side direction of the chassis 14. In other words, mounting regions Al where the lamp clips 18 are mounted in the long-side direction of the chassis 14 and non-mounting regions A2 where the lamp clips 18 are not mounted are alternately arrayed in the chassis 14. Each of the mounting region Al and the non-mounting region A2 has a predetermined width in the long-side direction of the chassis 14 and is formed into a strip shape extended along the short-side direction of the chassis 14.
Two mounting holes 32 and 33 are formed in the inner surfaces of the bottom plates of the chassis 14 for inserting the mounting portions 30 and 31 to positions at which each of the lamp clips 18 should be mounted while piercing in a thickness direction. In order to distinguish the mounting holes 32 and 23 from each other, the mounting holes 32 and 33 are sequentially referred to as a first mounting hole 32 and a second mounting hole 33 from the left illustrated in
The lamp gripping portion 28 constituting a support structure for the cold-cathode tube 17 will be described in detail. As illustrated in
A retaining projection 36 is provided in the inner surface (inner circumferential surface opposite to the cold-cathode tube 17) in a leading end portion of the arm portion 34 in order to retain the cold-cathode tube 17, and the opening 35 described above is secured between the retaining projections 36. The width of the opening 35 is set slightly narrower than an outside diameter dimension of the cold-cathode tube 17. Accordingly, in mounting or removing the cold-cathode tube 17 through the opening 35, the cold-cathode tube 17 presses the arm portions 34, whereby the arm portions 34 are elastically deformed and expanded. The retaining projection 36 hangs over inward (toward a center axis line side of the cold-cathode tube 17) from the inner surface in the leading end portion of the arm portion 34, and is located at a position at which the cold-cathode tube 17 is covered from the front side (light outgoing side), that is, the retaining projection 36 is located on the side in the direction in which the cold-cathode tube 17 drops out of. In the mounted state, the cold-cathode tube 17 is supported at three points, that is, a central first support point located immediately below the center of the cold-cathode tube 17 in the bottom surface of the lamp gripping portion 28 and second and third support points located at inner ends of the retaining projections 39. Between the support points, a slight gap (clearance) extending in the circumferential direction is provided between the outer circumference surface of the cold-cathode tube 17 and the inner circumference surface of the lamp gripping portion 28.
Guide portions 37 are provided in the outer surfaces in the leading end portions of the arm portions 34 in order to guide the operation to mount the cold-cathode tube 17. Each guide portion 37 is formed into a tapered shape while rising obliquely outward from the arm portion 34. The guide portions 37 have gradients from projection base ends to projection leading ends so as to be separated from each other. In addition, in the guide portions 40, the inner surfaces opposite to the cold-cathode tube 17 are formed into inclined surfaces having the similar gradients. Accordingly, an interval between the inner surfaces that are of surfaces opposite to each other in the guide portions 37 is gradually narrowed downward in the FIG., that is, in the direction in which the cold-cathode tube 17 is mounted, and the interval is gradually widened in the direction in which the cold-cathode tube 17 is detached. Therefore, the operation to mount the cold-cathode tube 17 can smoothly be guided by the inner surfaces of the guide portions 37. The inner surface of the guide portion 37 continues directly and smoothly into the inner surface of the retaining projection 36.
Next, the support pin 29 constituting the support structure for the diffuser plate 15a will be described in detail. As illustrated in
A detailed description will then be given of the mounting portions 30 and 31 constituting the retaining structure of the lamp clip 18 for the chassis 14 along with the mounting holes 32 and 33 in the chassis 14. First the retaining structure will briefly be described. As illustrated in
The first mounting portion 30 and the second mounting portion 31 have a common structure. The common structure will be described below. The first mounting portion 30 and the second mounting portion 31 include base portions 30a and 31a that are projected from a rear surface of the main body 27 and cantilever projections 30b and 31b that are projected (extended) along the long-side direction of the main body 27 while bent at a substantially right angle from leading ends of base portions 30a and 31a, respectively. The first mounting portion 30 and the second mounting portion 31 are formed into a substantially L-shape when viewed from the front face. The width dimensions and length dimensions of the first mounting portion 30 and second mounting portion 31 are set so as to be smaller than the short-side dimension and long-side dimension of the main body 27.
A difference of the structure between the first mounting portion 30 and the second mounting portion 31 will be described below. The guide portion 38 that can guide the operation to be mounted on the chassis 14 is provided at leading end of the projection 30b of the first mounting portion 30. The guide portion 38 is formed with a gradient that is away from the main body 27 toward the leading end side. A latching projection 39 that is projected toward the side of the main body 27 from leading end of the projection 31b of the second mounting portion 31 is provided. A tapered surface of the latching projection 39 is formed in a surface opposite to the main body 27. A surface of the latching projection 39 opposite to the base portion 31a in erects in substantially parallel with the outer surface of the base portion 31a and forms a substantially straight surface along the direction (Z-axis direction) orthogonal to the direction (Y-axis direction) in which the lamp clip 18 is slid to the chassis 14, thereby becoming a latching surface for the chassis 14.
The first mounting hole 32 and the second mounting hole 33, which are made in the chassis 14, will be described below. The first mounting hole 32 and the second mounting hole 33 are formed into a size that permits the insertion of the corresponding first mounting portion 30 and second mounting portion 31. More specifically, the first mounting hole 32 and the second mounting hole 33 are formed into rectangular shapes according to the first mounting portion 30 and the second mounting portion 31 when viewed from above, and the length dimensions and width dimensions of the first mounting hole 32 and second mounting hole 33 are smaller than those of the main body 27. Accordingly, in the state with the lamp clip 18 being mounted, the first mounting hole 32 and the second mounting hole 33 are closed by the main body 27. A latching hole 40 in which the latching projection 39 can be latched is made in the chassis 14 at the position adjacent to the second mounting hole 33. The latching hole 40 is made on the right with respect to the second mounting hole 33 as illustrated in
In the present embodiment, the reflecting sheet 23 is attached from the front side of the lamp clip 18 while the lamp clips 18 are mounted on the chassis 14 (
As described above, the reflecting sheet 23 has a size in which the substantially whole area of the inner surface of the bottom plate that is of the portion, on which the lamp clip 18 is mounted in the chassis 14. As illustrated in
As illustrated in
A width dimension (opening width), that is, the dimension in the X-axis direction of the opening 41 is set so as to be equal to or slightly larger than the dimension in the X-axis direction of the support pin 29. As described above, the dimension in the X-axis direction of the support pin 29 is larger than the dimension in the X-axis direction of the lamp gripping portion 28. On the other hand, a length dimension (opening length), that is, the dimension in the Y-axis direction of the opening 41 is larger than a distance between the arm portions 34 on end sides of the lamp gripping portions 28 located at both end positions. Accordingly, in assembling the reflecting sheet 23, the lamp gripping portions 28 and the support pin 29 are collectively passed through the opening 41.
When the reflecting sheet 23 is attached as illustrated in
When the reflecting sheet 23 is attached, while the most part of the reflecting sheet 23 except the inner edge portion 42 of each opening 41 constitutes a laying portion 23a that is laid on the inner surface of the chassis 23, the inner edge portion 42 of each opening 41 of the reflecting sheet 23 includes an overlapping portion 42a that runs over the outer edge portion 43 of the main body 27 to overlap the front side. The overlapping portion 42a is formed into the frame shape that is parallel to the outer edge portion 43 of the main body 27 when viewed from above. Accordingly, in the reflecting sheet 23, a difference in thickness corresponding to the thickness of the main body 27 in the Z-axis direction is generated between the overlapping portion 42a and the laying portion 23a with respect to the chassis 14. In the reflecting sheet 23, a portion located between the overlapping portion 42a and the laying portion 23a with respect to the chassis 14 constitutes an inclined portion 42b having a rising slope from the laying portion 23a toward the overlapping portion 42a. In other words, the inclined portion 42b is formed to be spread out from the overlapping portion 42a toward the laying portion 23a with respect to the chassis 14. The overlapping portion 42a and the laying portion 23a with respect to the chassis 14 are connected in a slope manner by the inclined portion 42b, thereby eliminating a step. A gap having a substantially triangular shape in section is provided between the inclined portion 42b and the outer circumference end surface in the outer circumference edge 43 of the main body 27. The inclined portion 42b is formed into the frame shape that further surrounds the overlapping portion 42a from the outside when viewed from above, and the outer circumference end surface at the outer circumference edge 43 of the main body 27 and the outside portion in the chassis 14 are covered over the whole circumference with the inclined portion 42b.
When the reflecting sheet 23 is attached, the lamp gripping portions 28 and the support pin 29 provided on the main body 27 are all inserted in the opening 41. Accordingly, the adjacent lamp gripping portions 28 face each other without the reflecting sheet 23 therebetween. Moreover, the lamp gripping portion 28 and the adjacent support pin 29 face each other without the reflecting sheet 23 therebetween.
In the present embodiment, the reflecting sheet 23 is not sandwiched between the chassis 14 and the main body 27 of the lamp clip 18. Correspondingly, in the present embodiment, a double-sided adhesive tape 44 is used to fix the reflecting sheet 23 to the chassis 14. In the configuration of the double-sided adhesive tape 44, adhesive agents (not illustrated) are disposed in both the front and the rear surfaces of a base material (not illustrated) that is formed into a strip shape having a predetermined width. As illustrated in
As illustrated in
Action of the present embodiment having the above-described structure will be described below. The liquid crystal panel 11 and the backlight device 12 are separately produced and assembled in each other using the bezel 13 or the like, thereby producing the liquid crystal display device 10 shown in
The work of mounting each lamp clip 18 on the chassis 14 is performed in advance of the assembly of the reflecting sheet 23. A worker grips the support pin 29 of the lamp clip 18, and pushes the mounting portions 30 and 31 into the bottom plate of the chassis 14 while aligned with the mounting holes 32 and 33. Therefore, the mounting portions 30 and 31 are inserted in the mounting holes 32 and 33. The surface on the backside of the main body 27 abuts on the surface of the chassis 14, and whereby the projections 30b and 31b are projected from the backside of the chassis 14. Then the lamp clip 18 is slid in the direction in which the projections 30b and 31b are projected (the right illustrated in
The work that assembles the reflecting sheet 23 in the chassis 14 is performed after the lamp clip 18 is completely mounted on the chassis 14 in the above-described manner. In advance of the assembly of the reflecting sheet 23, the double-sided adhesive tape 44 is adhered to the surface (surface opposite to the chassis 14) on the backside of the reflecting sheet 23. At this point, as illustrated in
The reflecting sheet 23 is adhered to the chassis 14 after the double-sided adhesive tape 44 is adhered to the non-formation region A4 in the reflecting sheet 23. As illustrated in
After the lamp gripping portions 28 and the support pin 29 are passed through the opening 41, the outer edge portion 43 of the main body 27 is covered with the inner edge portion 42 of the opening 41. When the most part of the reflecting sheet 23 abuts on the inner surface of the bottom plate of the chassis 14, as illustrated in
After reflecting sheet 23 is attached in the above-described way, the cold-cathode tube 17 is mounted on each lamp gripping portion 28 of the lamp clip 18, and the holder 20 is mounted. Then, when the diffuser plate 15a and the optical sheet 15b are placed while stacked, the liquid crystal panel 11 is placed from the front side, and the bezel 13 is assembled to assemble the liquid crystal display device 10.
The action in lighting each cold-cathode tube 17 in the backlight device 12 will be described below. As illustrated in
Because the lamp clip 18 mounted on the chassis 14 includes the main body 27 having the predetermined thickness, a step is generated between the chassis 14 and the outer edge portion 43 of the main body 27. Therefore, assuming that the outer edge portion 43 of the main body 27 is exposed to the side of the diffuser plate 15a, an outer circumference end surface of the outer edge portion 43 and a portion surrounding thereof are hardly illuminated with the light emitted from the cold-cathode tube 17, thereby easily generating a shadow. On the other hand, in the present embodiment, because the outer edge portion 43 of the main body 27 is covered from the front side with the inner edge portion 42 of the opening 41 in the reflecting sheet 23, the shadow is hardly generated by the outer edge portion 43 of the main body 27. More specifically, the inner edge portion 42 of the opening 41 includes the overlapping portion 42a that runs over and overlaps the outer edge portion 43 of the main body 27 and the inclined portion 42b that is spread out from the overlapping portion 42a toward the laying portion 23a, and covers the outer edge portion 43 of the main body 27 over the whole circumference. This rarely generates the region that is hardly illuminated with the light emitted from the cold-cathode tube 17. In other words, because the laying portion 23a, overlapping portion 42a, and inclined portion 42b in the reflecting sheet 23 are substantially evenly illuminated with the light emitted from the cold-cathode tube 17, the shadow is hardly generated compared with the case in which the outer edge portion 43 of the main body 27 is exposed to the side of the diffuser plate 15a. Therefore, the luminance unevenness is less likely to occur in the backlight device 12.
In the present embodiment, the outer edge portion 43 of the main body 27 in the lamp clip 18 is covered with the reflecting sheet 23, thereby taking the countermeasure for the luminance unevenness. On the other hand, when the countermeasure for the luminance unevenness is taken by devising the shape of the lamp clip like the conventional technology, the cost increases caused by the need of newly producing the lamp clip having the special structure and the need of exchanging the lamp clip from the general-purpose product arise. On the other hand, in the present embodiment, although the need of forming the opening 41 in the reflecting sheet 23 arises, only one component that is of the reflecting sheet 23 is subjected to the processing. In addition, the processing is also performed at low cost, and the general-purpose product conventionally used can directly be used as the lamp clip 18. Therefore, this configuration can be dealt with at low cost as a whole.
Additionally, in the present embodiment, a ratio of a surface area of the whole lamp clip 18 to a surface area of the reflecting sheet 23 lowers by the portion in which each lamp clip 18 is covered with the reflecting sheet 23. For example, when the lamp clip 18 is lower than the reflecting sheet 23 in reflectance, the lamp clip 18 is easily visually recognized as darker than the reflecting sheet 23, so that the lamp clip 18 tends to be easily visually recognized as a dark portion with increasing the ratio of the surface area of the lamp clip 18. On the other hand, in the present embodiment, the ratio of the surface area of the whole reflecting sheet 23 to the surface area of the lamp clip 18 can be increased by the area in which each lamp clip 18 is covered with the reflecting sheet 23. Therefore, the luminance unevenness is less likely to occur in the backlight device 12 even if the reflectivity of the lamp clip 18 is lower than that of the reflecting sheet 23. As used herein, the “surface area” means an area of a portion in which the reflecting sheet 23 or the lamp clip 18 is exposed to the cold-cathode tube 17 or the diffuser plate 15a.
As described above, according to the present embodiment, the backlight device 12 includes the chassis 14, the cold-cathode tube 17 disposed in the chassis 14, the main body 27 mounted on the chassis 14, the lamp clip 18 having the lamp gripping portion 28 and the reflecting sheet 23 disposed in the chassis 14. The lamp clip 18 is provided on the main body 27 so as to grip the cold-cathode tube 17. The reflecting sheet 23 has the opening 41 through which the lamp gripping portion 28 is passed and inner edge portion thereof covers the outer edge portion of the main body 27.
Because the outer edge portion 43 of the main body 27 is covered with the inner edge portion 42 of the opening 41 while the lamp gripping portion 28 that grips the lamp in the lamp clip 18 is passed through the opening 41 of the reflecting sheet 23, the outer edge portion 43 that forms the step between the chassis 14 and the outer edge portion 43 in the main body 27 can be hardly visually recognized as the shadow. In the present embodiment, the reflecting sheet restricts the generation of the shadow in the outer edge portion 43 of the main body 27, so that the general-purpose product can be used as the lamp clip 18. Therefore this configuration achieves the cost reduction. Additionally, because the lamp clip 18 is covered with the reflecting sheet 23, the ratio of the surface area of the lamp clip 18 to the surface area of the reflecting sheet 23 is decreased. Therefore, the luminance unevenness is less likely to occur even if the lamp clip 18 and the reflecting sheet 23 have different reflection efficiencies. Therefore, this configuration is suitable to the thinner liquid crystal display device.
The main body 27 is formed into the rectangular shape, and at least the long-side v portion 43a in the outer edge portion 43 of the main body 27 is covered with the inner edge portion 42 of the opening 41 in the reflecting sheet 23. Because the long-side outer edge portion 43 in the outer edge portion 43 of the rectangular main body 27 is a region where the shadow is easily noticeable compared with the short-side outer edge portion 43b, at least the long-side outer edge portion 43a is covered with the of the inner edge portion 42 of the opening 41 in the reflecting sheet 23. Therefore, the luminance unevenness is further effectively reduced.
The outer edge portion 43 of the main body 27 is covered over the whole circumference with the inner edge portion 43 of the opening 41 in the reflecting sheet 23. Because the outer edge portion 43 of the main body 27 is less likely to be visually recognized as the shadow, the luminance unevenness is very effectively reduced.
The plurality of lamp gripping portions 28 are provided on the main body 27 and all inserted in the opening 41. Therefore, when the lamp gripping portions 28 are passed through the opening 41 in assembling the reflecting sheet 23, the lamp gripping portions 28 are hardly hooked in the reflecting sheet 23. Consequently, this configuration is excellent in the assembly workability of the reflecting sheet 23.
The support pin 29 that can support the diffuser plate 15a is provided in the main body 27 while the diffuser plate 15a is disposed at the position at which the cold-cathode tube 17 is sandwiched between the diffuser plate 15a and the chassis 14, and the support pin 29 is passed through the opening 41. Therefore, when the reflecting sheet 23 is assembled, the support pin 29 is passed through the opening 41. The diffuser plate 15a can be supported well by the support pin 29.
The opening 41 surrounds the lamp gripping portions 28 and the support pin 29 collectively. Therefore, when the lamp gripping portions 28 and the support pin 29 are passed through the opening 41 in assembling the reflecting sheet 23, the lamp gripping portions 28 and the support pin 29 are hardly hooked in the reflecting sheet 23. This configuration is excellent in the assembly workability of the reflecting sheet 23.
The diffuser plate 15a is disposed such that the cold-cathode tube 17 is sandwiched between the diffuser plate 15a and the chassis 14. The support pin 29 that supports the diffuser plate 15a and a plurality of the lamp gripping portions 28 are provided on the main body 27. The support pin 29 is passed through the opening 41. The lamp gripping portions 28 and the support pin 29 are all inserted in the opening 41. Therefore, when the lamp gripping portions 28 and the support pin 29 are passed through the opening 41 in assembling the reflecting sheet 23, the lamp gripping portions 28 and the support pin 29 are hardly hooked in the reflecting sheet 23. As a consequence, this configuration is further excellent in the assembly workability of the reflecting sheet 23.
The opening 41 has the width that is constant over the total length. The width measures in the direction perpendicular to the direction in which the lamp gripping portions 28 and the support pin 29 are aligned. Namely, the shape of the opening 41 is simple and thus the inner edge portion 42 of the opening 41 is less likely to be deformed.
The double-sided adhesive tape 44 is included in order to fix the reflecting sheet 23 to the chassis 14. When the outer edge portion 43 of the main body 27 is covered with the inner edge portion 42 of the opening 41 of the reflecting sheet 23, the reflecting sheet 23 is hardly fixed by the lamp clip 18. However, according to the configuration described above, because the reflecting sheet 23 can be fixed to the chassis 14 by the double-sided adhesive tape 44, this configuration can maintain the state in which the outer edge portion 43 of the main body 27 is covered with the inner edge portion 42 of the opening 41. Additionally, this configuration is suitable to the cost reduction.
A plurality of the lamp clips 18 are mounted on the chassis 14 and the reflecting sheet 23 has a plurality of the openings 41 at the positions corresponding to the lamp clips 18. The outer edge portions 43 of the main bodies 27 of the multiple lamp clips 18 are covered with a single reflecting sheet 23. In comparison to an illuminating device in which a reflecting sheet is used for each lamp clip, better assembly workability at a low cost. Additionally, this configuration is extremely excellent in the assembly workability because the substantially whole area of the chassis 14 is covered with the reflecting sheet 23.
In the cold-cathode tube 17 used in the present embodiment, the tube diameter is set to 4.0 mm, the distance between the cold-cathode tube 17 and the reflecting sheet 23 is set to 0.8 mm, the distance between the adjacent cold-cathode tubes 17 is set to 16.4 mm, and the distance between the cold-cathode tube 17 and the diffuser plate 15a is set to 2.7 mm. In the backlight device 12, the distance between the constituents decreases to achieve a thinner device, particularly the distance between the cold-cathode tube 17 and the diffuser plate 15a and the distance between the cold-cathode tube 17 and the reflecting sheet 23 decrease. Using the thinner backlight device 12, the thickness (that is, the thickness from the surface of the liquid crystal panel 11 to the rear surface of the backlight device 12) of the liquid crystal display device 10 can be set to 16 mm, and the thickness (that is, the thickness from the surface of the front-side cabinet Ca to the rear surface of the backside cabinet Cb) of the television receiver TV can be set to 34 mm, thereby implementing the flat-screen television receiver.
A second embodiment of the invention will be described with reference to
As illustrated in
As described above, according to the present embodiment, the lamp gripping portions 28-A and the support pin 29-A are provided such that the distance D1 from the outer edge of the of the lamp gripping portion 28-A to the outer end of the main body 27-A differs from the distance D2 from the outer edge of the support pin 29-A to the outer edge of the main body 27-A. The distances D1 and D2 measure in the direction perpendicular to the direction in which the lamp gripping portion 28-A and the support pin 29-A are aligned. In addition, the opening 41-A has a part 41a having a small with and a part 41b having a large width. One of the lamp gripping portion 28-A and the support pin 29-A, whichever the distance to the outer edge of the main body 27-A is smaller, is passed through the part 41b having the large width. The other one, the distance from which to the outer edge of the main body 27-A is larger, is passed through the part 41a having the small width. Even if the lamp gripping portion 28-A and the support pin 29-A have different sizes that measure in the direction perpendicular to the direction in which the lamp gripping portions 28-A and the support pin 29-A are aligned, the areas of the lamp clip 18-A covered with the reflecting sheet 23-A can be increased by forming the opening 41-A with different widths corresponding to the sizes of the lamp gripping portions 28-A and support pin 29-A. Therefore, even if the lamp clip 18-A differs from the reflecting sheet 23-A in the reflection efficiency. Therefore, the luminance unevenness is further less likely to occur.
A third embodiment of the present invention will be described with reference to
As illustrated in
The reflecting sheet 23-B partially remains between the adjacent openings 46, 47. The partially remaining reflecting sheet 23-B includes covering portions 48 and 49 that covers the middle portion of a main body 27-B between the lamp gripping portions 28-B and the middle portion of the main body 27-B between the lamp gripping portion 28-B and the support pin 29-B. Specifically, the reflecting sheet 23-B remaining between the adjacent openings 46 includes the first covering portion 48 that covers the middle portion of the main body 27-B between the adjacent lamp gripping portions 28-B. The first covering portion 48 is formed so as to be substantially equal to or smaller than an interval between the adjacent lamp gripping portions 28-B in the Y-axis direction. On the other hand, the reflecting sheet 23-B remaining between the opening 46 and the adjacent opening 47 includes the second covering portion 49 that covers the middle portion of the main body 27-B between the lamp gripping portion 28-B and the adjacent support pin 29-B. The second covering portion 49 is formed so as to be substantially equal to or smaller than an interval between the lamp gripping portion 28-B and support pin 29-B which are adjacent to each other in the Y-axis direction, and so as to be smaller than the first covering portion 48.
When the reflecting sheet 23-B is assembled in the chassis 14-B after the lamp clips 18-B are mounted on the chassis 14-B, the following procedure is performed. That is, as illustrated in
When the reflecting sheet 23-B is attached to the chassis 14-B, as illustrated in
As described above, according to the present embodiment, the plurality of lamp gripping portions 28-B are provided on the main body 27-B. The reflecting sheet 23-B has a plurality of openings 46 such that each of the lamp gripping portions 28-B is inserted in corresponding one of the openings 46. The reflecting sheet 23-B also has the first covering portion 48 that covers an area of the main body 27-B between the adjacent lamp gripping portions 28-B. The first covering portion 48 is located between the adjacent openings 46. Therefore, the portion of the main body 27-B between the adjacent lamp gripping portions 28-B is covered with the first covering portion 48 located between the adjacent openings 46, whereby the covered area of the reflecting sheet 23-B with respect to the lamp clip 18-B is increased. Even if the lamp clip 18-B and the reflecting sheet 23-B have different reflection efficiencies, the luminance unevenness is less likely to occur. The first covering portion 48 bridges between the adjacent openings 46 separated from each other. This restricts the reflecting sheet 23-B from being deformed so as to widen the opening 46-B. In addition, this suppresses the deformation of the inner edge portion 46a of the opening 46-B.
The reflecting sheet 23-B has a plurality of openings 46, 47 such that the lamp gripping portions 28-B and support pin 29-B are inserted in the respective openings 46, 47. The reflecting sheet 23-B also has the second covering portions 49 between the adjacent openings 46, 47. The second covering portions 49 cover the areas of the main body 27-B between the lamp gripping portions 28-B and the adjacent support pin 29-B. Because the areas of the main body 27-B between the lamp gripping portions 28-B and the adjacent support pin 29-B is covered with the second covering portion 49, the areas of the lamp clip 18-B covered by the reflecting sheet 23-B is increased. Even if the lamp clip 18-B and the reflecting sheet 23-B have reflection efficiencies, the luminance unevenness is less likely to occur. Additionally, each second covering portion 49 bridges between the adjacent openings 46, 47 separated from each other. Therefore, reflecting sheet 23-B is restricted form being deformed so as to widen the openings 46, 47. In addition, this suppresses the deformation of the inner edge portions 46a, 47a of the openings 46, 47.
The reflecting sheet 23-B has a plurality of the openings 46, 47 such that the lamp gripping portions 28-B and the support pin 29-B are inserted in the respective openings 46, 47. The reflecting sheet 23-B also has the first covering portion 48 that covers an area of the main body 27-B between the adjacent lamp gripping portions 28-B and the second covering portion 49 that covers an area of the main body 27-B between the lamp gripping portion 28-B and the adjacent support pin 29-B. The first covering portion 48 and the second covering portion 49 are located between the adjacent openings 46, 47, respectively. Therefore, the area of the main body 27-B between the adjacent lamp gripping portions 28-B and the area of the main body 27-B between the lamp gripping portion 28-B and the adjacent support pin 29-B are entirely covered with the first covering portion 48 and second covering portion 49. This further increases the covered area of the reflecting sheet 23-B with respect to the lamp clip 18-B. Accordingly, even if the lamp clip 18-B and the reflecting sheet 23-B have the reflection efficiencies, the luminance unevenness is less likely to occur.
A fourth embodiment of the present invention will be described with reference to
As illustrated in
As described above, according to the present embodiment, the lamp gripping portions 28-C and the support pin 29-C are provided such that the distance from the outer edge of the lamp gripping portion 28-C to the outer edge of the main body 27-C differs from the distance from the outer end of the support pin 29-C to the outer edge of the main body 27-C. The distances measure in the direction perpendicular to the direction in which the lamp gripping portions 28-C and the support pin 29-C are aligned. The width of the opening 47-C that measures at a part through which one of the lamp gripping portion a openings 46-C, 47-C having the smaller distance between the lamp gripping portion 28-C and the support pin 29-C is passed becomes larger, and the opening width of the opening 46-C through which one of the openings 46-C, 47-C having the larger distance between the lamp gripping portion 28-C and the support pin 29-C is passed becomes smaller. In the direction orthogonal to the direction in which the lamp gripping portions 28-C and the support pin 29-C are arrayed, even if the lamp gripping portion 28-C differs from the support pin 29-C in the size, the covered area of the reflecting sheet 23-C with respect to the lamp clip 18-C can be enlarged by forming the openings 46-C, 47-C into the opening width corresponding to the sizes of the lamp gripping portions 28-C and support pin 29-C. Therefore, even if the lamp clip 18-C differs from the reflecting sheet 23-C in the reflection efficiency. Therefore, the luminance unevenness is further less likely to occur.
A fifth embodiment of the present invention will be described with reference to
As illustrated in
In mounting the reflecting sheet 23-D on the chassis 14-D, the outer edge portion 43-D of the main body 27-D is covered with an inner edge portion 42-D of an opening 41-D when the reflecting sheet 23-D is laid on the chassis 14-D in the state illustrated in
As described above, according to the present embodiment, the outer edge portion 43-D of the main body 27-D is formed into the shape that is spread out toward the outer end side. Accordingly, because the reflecting sheet 23-D is laid on along the spread-out outer edge portion 43-D of the main body 27-D, the inner edge portion 42-D of the opening 41-D that covers the outer edge portion 43-D of the main body 27-D is maintained in the similar spread-out shape. Therefore, the luminance unevenness is less likely to occur. This configuration also restricts the reflecting sheet 23-D from interfering in the outer edge portion 43-D of the main body 27-D to generate the damage.
A sixth embodiment of the present invention will be described with reference to
As illustrated in
A reflecting member 51 that is a different component from the reflecting sheet 23-E is laid on the lamp clip 18-E that is mounted on the chassis 14-E with the reflecting sheet 23-E placed therebetween. The reflecting member 51 is made of the same material as the reflecting sheet 23-E. As illustrated in
The work that mounts each lamp clip 18-E is performed after the reflecting sheet 23-E is attached to the chassis 14-E. Then the work that separately mounts the reflecting member 51 corresponding to each lamp clip 18-E is performed. When the reflecting member 51 is laid on the lamp clip 18-E while the opening 54 is positioned with respect to the lamp gripping portions 28-E and support pin 29-E in the lamp clip 18-E that should be mounted, the lamp gripping portions 28-E and the support pin 29-E are passed through the opening 54. When the reflecting member 51 is attached, the outer edge portion 43-E of the main body 27-E is covered over the whole circumference with an inner edge portion 54a of the opening 54, and the outer edge portion of the reflecting member 51 and the reflecting sheet 23-E are adhered rigidly by the double-sided adhesive tape 55.
A seventh embodiment of the present invention will be described with reference to
As illustrated in
When the lamp clip 18-F is pushed into the chassis 14-F along the Z-axis direction from the front side, the mounting portions 30-F and 31-F are inserted in the mounting holes 32-F and 33-F to tentatively and elastically deform the projections 30b-F and 31b-F. When the lamp clip 18-F is pushed into a regular depth, the mounting portions 30-F and 31-F are projected to the backside of the chassis 14-F, and the projections 30b-F and 31b-F-F are restored to latch the latching surfaces in peripheral edge portions of the mounting holes 32-F and 33-F in the chassis 14-F from the backside. With this configuration, the lamp clip 18-F is maintained in the mounted state with respect to the chassis 14-F. In addition to the lamp clip 18 of the slide-mount type of the first to sixth embodiments, this configuration also preferably reduces the luminance unevenness in the lamp clip 18-F of the push-mount type of the seventh embodiment. Additionally, because the second mounting portion 31-F is placed immediately below the support pin 29-F, operability is improved in mounting the lamp clip 18-F on the chassis 14-F.
An eighth embodiment of the present invention will be described with reference to
As illustrated in
An opening 60 through which the support pin 58 of the optical member support 56 is passed is provided in a reflecting sheet 23-G. The opening 60 is formed into a size that is smaller than the main body 57 of the optical member support 56. When the reflecting sheet 23-G is laid on from the front side of the optical member support 56 while the optical member support 56 is mounted on the chassis 14-G, an outer edge portion 57a of the main body 57 of the optical member support 56 is covered over the whole circumference with the inner edge portion 60a of the opening 60. Therefore, the outer edge portion 57a of the main body 57 of the optical member support 56 is hardly visually recognized as the shadow, and whereby the ratio of the surface area of the optical member support 56 to the surface area of the reflecting sheet 23-G is decreased by the area in which the optical member support 56 is covered with the reflecting sheet 23-G. Accordingly, this configuration is suitable to reduce the luminance unevenness.
As described above, according to the present embodiment, in the optical member support 56 including the main body 57 that is mounted on the chassis 14-G, and the support pin 58 that is provided in the main body 57 to be able to support the diffuser plate 15a-G, the opening 60 through which the support pin 58 is passed is provided in the reflecting sheet 23-G, and the outer edge portion 57a of the main body 57 is covered with the inner edge portion 60a of the opening 60. Therefore, the support pin 58-G of the optical member support 56, which supports the diffuser plate 15a-G is passed through the opening 60 of the reflecting sheet 23-G, and the outer edge portion 57a of the main body 57 is covered with the inner edge portion 60a of the opening 60, so that the outer edge portion 57a of the main body 57, which forms the step between the outer edge portion 57a and the chassis 14-G, is hardly visually recognized as the shadow. In the present embodiment, the reflecting sheet 23-G reduces the generation of the shadow in the outer edge portion 57a of the main body 57, so that the general-purpose product can be used as the optical member support 56 to achieve the cost reduction. Additionally, because the optical member support 56 is covered with the reflecting sheet 23-G, the ratio of the surface area of the optical member support 56 to the surface area of the reflecting sheet 23-G is decreased. Therefore, the luminance unevenness is less likely to occur even if the optical member support 56 and the reflecting sheet 23-G have different reflection efficiencies. Accordingly, this configuration is suitable to the thinner liquid crystal display device.
The present invention is not limited to the embodiment explained by the description and drawings, but, for example, the following embodiments are also included in the technical scope of the invention.
(1) In the first to seventh embodiments described above, the opening of the reflecting sheet surrounds the lamp gripping portions and the support pin in the lamp clip collectively, or the opening individually passes the lamp gripping portions and the support pin in the lamp clip therethrough. On the other hand, the invention may also encompass a configuration in which an individual opening through which the lamp gripping portion or the support pin is individually passed and a collective opening through which the plurality of lamp gripping portions are collectively passed or a composite type collective opening through which the lamp gripping portion and the support pin are collectively passed are combined.
(2) For example, as illustrated in
(3) In the embodiments described above, the outer edge portion of the main body is covered over the whole circumference with the inner edge portion of the opening. On the other hand, the invention may also encompass a configuration in which the outer edge portion of the main body is partially covered. For example, when at least the long-side outer edge portion in the outer edge portion of the main body is covered with the inner edge portion of the opening, the short-side outer edge portion is hardly noticeable as the shadow even if the short-side outer edge portion in the outer edge portion of the main body is exposed. Therefore, a certain effect of suppressing the luminance unevenness is obtained.
(4) In addition to the above description (3), for example, in a configuration in which the lamp gripping portion or the support pin is formed in the total width region of the main body, the outer edge portion of the main body may be covered with the inner edge portion of the opening with respect to the portion except the portion in which the lamp gripping portion or the support pin is placed. The invention may also encompass this configuration. Additionally, the range where the outer edge portion of the main body is covered with the inner edge portion of the opening can appropriately be changed.
(5) In the third and fourth embodiments described above, the opening through which the support pin is passed is formed into the quadrangular shape according to other openings for lamp gripping portions. The invention may also encompass a configuration in which the opening for a support ping is formed into a circular shape according to (along) a planar shape (outer shape) of the support pin. Therefore, the covered area of the reflecting sheet with respect to the main body can further be increased.
(6) In addition to the embodiments described above, the sizes, shapes and the number of lamp gripping portions or support pins can appropriately be changed. Correspondingly, the size, shape and the number of openings can also appropriately be changed. Specifically, in the embodiments described above, the lamp gripping portion in the X-axis direction is smaller than the support pin in the X-axis direction. On the other hand, the invention may also encompass a configuration in which the support pin is smaller than the lamp gripping portion. At this point, the technology described in the second and fourth embodiments is applied to match the opening width of the opening with the sizes of the lamp gripping portions and support pin, which allows the covered area of the reflecting sheet with respect to the main body to be increased.
(7) In the third and fourth embodiments described above, each covering portion is formed to be the bridge between the adjacent openings. On the other hand, the invention may also encompass a configuration in which the covering portion is cut by a slit in midstream while the adjacent openings are communicated by the slit. Therefore, the covering portion can be deformed so as to turn up at the slit, so that the work that passes the lamp gripping portions and support pin through the opening is facilitated in mounting the reflecting sheet. In the mounted state, the increase in covered area of the reflecting sheet with respect to the main body can be achieved by covering the main body with the covering portion.
(8) In the embodiments described above, the main body is formed into the rectangular shape. Additionally, the invention may also encompass, for example, a configuration in which the main body is formed into a square shape, a circular shape, or an ellipsoidal shape.
(9) In addition to the embodiments described above, the point at which the double-sided adhesive tape is placed can appropriately be changed. For example, the double-sided adhesive tape may be placed near the chassis or the outer edge portion in the reflecting sheet.
(10) In the embodiments described above, the double-sided adhesive tape is used as the mounting member that mounts the reflecting sheet on the chassis by way of example. Alternatively, for example, an adhesive agent may be used. Alternatively, another mounting member that mechanically or chemically fixes the reflecting sheet to the chassis can be used.
(11) Except the embodiments described above, the numbers of mounting portions and mounting holes can appropriately be changed. The shapes of the mounting portion and mounting hole can appropriately be changed.
(12) In the embodiments described above, the mounting portion and the mounting hole are made in order to mount the lamp clip on the chassis. The invention may also encompass, for example, a configuration, in which the lamp clip is mounted on the chassis by interposing the double-sided adhesive tape between the chassis and the rear surface of the main body in the lamp clip to eliminate the mounting portion and the mounting hole.
(13) In the embodiments described above, the cold-cathode tube is used as the light source. The invention may also encompass a configuration in which another kind of light source such as a hot-cathode tube is used.
(14) In the embodiments, the chassis is made of the sheet metal. Alternatively the chassis may be formed by resin molding.
(15) In the embodiments described above, the TFT is used as the switching element of the liquid crystal display device. Additionally, the invention can be applied to a liquid crystal display device in which a switching element (such as Thin Film Diode (TFD)) except the TFT is used, and can also be applied to a monochrome liquid crystal display device in addition to the color liquid crystal display device.
(16) In the embodiments described above, the liquid crystal display device in which the liquid crystal panel is used is illustrated as the display panel. The invention can also be applied to a display device in which another kind of display panel is used.
(17) In the embodiments described above, the television receiver including the tuner is illustrated. The invention can also be applied to a display device that does not include the tuner.
Number | Date | Country | Kind |
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2008-046780 | Feb 2008 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2009/051724 | 2/2/2009 | WO | 00 | 8/3/2010 |