WO2007102249A1

WO2007102249A1 - Lighting apparatus for display panel and display device

Info

Publication number: WO2007102249A1
Application number: PCT/JP2006/320959
Authority: WO
Inventors: Kentaroh Aoki
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2006-03-07
Filing date: 2006-10-20
Publication date: 2007-09-13
Also published as: JP2009122131A

Abstract

A cold cathode tube (23) configuring a backlight (12) is arranged on the rear side of a liquid crystal panel (11). The backlight (12) is provided with a case (21) wherein the cold cathode tube (23) is stored, and an optical member (22) arranged on the opening section side of the case (21). On the end portions of the cold cathode tube (23), holders (25) are mounted, and holder covers (26) for covering the end portions of the cold cathode tube (23) and the holders (25) are attached. The holders (25) are held to be displaced in a vertical direction to the holder covers (26), i.e., a direction of becoming close to or separated from the liquid crystal panel (11), and the end portions of the cold cathode tube (23) are permitted to be displaced in the same direction with such displacement of the holder.

Description

Specification

Illumination device and display device for display panel

Technical field

[0001] The present invention relates to a lighting device and a display device for a display panel.

Background art

[0002] A liquid crystal display device, which is a kind of display device, is roughly composed of a liquid crystal panel for displaying an image and a knock light as an external light source, and is particularly arranged on the back side of the liquid crystal panel. This backlight is called a direct type.

[0003] As an example of such a direct type backlight, one described in Patent Document 1 below is known. This backlight is composed of a box-shaped base whose upper surface is open, a plurality of fluorescent tubes mounted in the base, and a plurality of optical sheets arranged in a stacked state in the opening of the base. The Each fluorescent tube is supported with respect to the base in a posture parallel to the surface direction of the liquid crystal panel. The light emitted from each fluorescent tube is supplied to the liquid crystal panel through each optical sheet.

Patent Document 1: Japanese Patent Laid-Open No. 2001-22285

Disclosure of the invention

[0004] The fluorescent tube, which is the light source of the backlight described above, is a kind of linear light source, and its light distribution is as follows. That is, when the linear light source 1 (fluorescent tube) is viewed from the side in the axial direction, as shown in FIG. 11, the direction perpendicular to the axial direction has the highest light intensity, and as it approaches the axial direction from there. The light intensity gradually decreases.

Therefore, as described above, when each fluorescent tube is arranged in a posture parallel to the surface direction of the liquid crystal panel, it looks sufficiently bright when viewed from the front, but when viewed from an oblique direction. There is a problem that it looks relatively dark. In particular, there has been a problem when the installed liquid crystal display device must be viewed from an oblique direction due to restrictions on the installation location of the liquid crystal display device and the viewing location of the user of the liquid crystal display device.

[0006] The present invention has been completed based on the above situation, and an object thereof is to always obtain a good display quality regardless of the situation. [0007] An illumination device for a display panel according to the present invention is arranged on the back side of the display panel and emits light toward the display panel, and the linear light source with respect to the surface direction of the display panel. Movable means for displacing the linear light source so that the angle formed by the axis of the light source changes.

In the light distribution of the linear light source, the light intensity in the direction orthogonal to the axial direction is the largest, and the light intensity gradually decreases as it approaches the axial direction. In the present invention, by displacing the linear light source by the movable means, the angle formed by the axis of the linear light source with respect to the surface direction of the display panel can be changed, so that the entire light distribution of the linear light source is tilted. It becomes possible. Therefore, even when there are restrictions such as the installation location and the display panel can only be seen with a predetermined directional force, sufficient brightness is ensured by adjusting the angle of the linear light source according to the direction. can do.

As an embodiment of the present invention, the following configuration is preferable.

(1) The movable means is configured to include a movable portion that is attached to the end portion of the linear light source and that displaces the end portion in a direction in which the end portion is in contact with or separated from the display panel. As a result, it is possible to avoid the light emitted from the linear light source force from being blocked by the movable portion, and to maintain good display quality.

(2) A plurality of linear light sources are provided, a plurality of movable means are provided, and each movable means is connected to a different linear light source. As a result, the linear light sources connected by the respective movable means can be displaced independently of each other, which is more suitable for viewing the display panel from different directions.

(3) The adjacent linear light sources are connected to different movable means. As a result, the linear light sources adjacent to each other can be displaced independently of each other by each movable means, so even when the entire display panel is viewed from different directions, the brightness of the entire display panel is uneven. Is less likely to occur.

[0012] (4) The movable means includes a holding unit capable of holding the movable unit at a plurality of different positions, and an operation unit connected to the movable unit and capable of moving the movable unit as an external cover. To do. Thus, when the operation unit is operated from the outside, the movable unit is moved, and the linear light source is displaced accordingly. The movable part is held at a predetermined position by the holding part. Angle of linear light source The external force can be adjusted manually.

[0013] (5) The movable means is composed of an electric actuator that moves the movable portion, and an input unit that controls the operation of the electric actuator. Thus, by controlling the operation of the electric actuator by the input unit, the movable unit can be moved and the linear light source can be displaced.

[0014] (6) The input unit includes a receiving unit capable of receiving a signal from a transmitter for remote operation. Thereby, the linear light source can be displaced by remote operation.

(7) It is assumed that a support portion that supports the central portion in the length direction of the linear light source is provided.

Thereby, when the linear light source is displaced by the movable means, it is displaced in a seesaw shape with the support portion as a fulcrum.

(8) The linear light source is constituted by a discharge tube such as a hot cathode tube, a cold cathode tube, or a xenon tube.

(9) The linear light source has a configuration in which a plurality of point light sources are linearly arranged.

[0018] According to the present invention, it is possible to always obtain a good display quality regardless of the situation.

Brief Description of Drawings

FIG. 1 is a schematic exploded perspective view of a liquid crystal display device according to Embodiment 1 of the present invention.

[Figure 2] Cross section of liquid crystal display

[Figure 3] Side view of holder and holder cover

FIG. 4 is a cross-sectional view showing a state where the cold cathode tube is inclined to the right.

FIG. 5 is a cross-sectional view showing a state in which the cold-cathode tube is inclined upward to the left

FIG. 6 is a schematic plan view of a cold cathode tube and a holder according to Embodiment 2 of the present invention.

FIG. 7 is a cross-sectional view showing a state in which one cold cathode tube group has an upwardly inclined posture and the other cold cathode tube group has an upper left force S-like inclined posture.

FIG. 8 is a cross-sectional view showing a state in which one cold cathode tube group is set in a horizontal posture and the other cold cathode tube group is set in an upwardly inclined posture.

FIG. 9 is a cross-sectional view showing a state in which one cold cathode tube group is set in a horizontal posture and the other cold cathode tube group is set in a tilted posture in an upward left direction.

FIG. 10 is a schematic sectional view of an electric movable means according to Embodiment 3 of the present invention. 圆 11] Explanatory diagram of light distribution of conventional linear light source

Explanation of symbols

[0020] 10.-. 揿 ta display device (display device)

11. LCD panel (display panel)

12. .. Backlight (lighting device)

23.-. Cold cathode tube (Linear light source)

24. .. Support

25, 40 ... Holder (movable means, movable part)

26. .. Holder cover (movable means, holding part)

35, 43 ...

42.-. Connection part (movable means)

52. .. Electric motor (movable means, electric actuator) BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 of the present invention will be described with reference to FIGS. Embodiment 1 shows a liquid crystal display device 10 which is a kind of display device. In the following, the vertical and left-right directions are based on Figure 2.

As shown in FIG. 1 and FIG. 2, the liquid crystal display device 10 is roughly arranged on the liquid crystal panel 11 and the back side (back side) for displaying images and the like while having translucency. A backlight 12 that is an external light source to be held, and a substantially frame-shaped bezel 13 for holding the liquid crystal panel 11. The liquid crystal panel 11 is received by the frame 14 forming the knock light 12 and is held in a state of being sandwiched between the frame 14 and the bezel 13 fixed by screws B to the frame 14 from the front side. Come on!

[0023] The liquid crystal panel 11 roughly includes a pair of glass substrates 15, a liquid crystal 16 filled between the glass substrates 15, and an outer surface of the glass substrates 15 (surface opposite to the liquid crystal 16 side). And a pair of polarizing plates 17 to be attached to. Both glass substrates 15 face each other and are bonded together with a predetermined gap between them by a spacer, and the liquid crystal 16 filled therebetween is surrounded by a sealant 18. The glass substrate 15 on the back side is orthogonal to each other The switching element (for example, TFT) force connected to the source wiring and the gate wiring to be mounted on the front glass substrate 15 is provided with R, G, and B pixel electrodes in a matrix. One end of SOF19 (System On Film) is connected to the end of the glass substrate 15 on the back side via an anisotropic conductive film (ACF) to the source wiring and gate wiring, and the other end of the SOF19 A printed circuit board 20 is connected to the side. The printed circuit board 20 is fixed to the frame 14 with screws in a vertical posture while bending the S OF 19.

[0024] Next, the backlight 12 will be described in detail. As shown in FIG. 2, the backlight 12 roughly covers a rectangular metal case 21 having an opening on the upper surface side (liquid crystal panel side) and the opening of the case 21. Can be held in a state where the optical member 22 is sandwiched between the case 21 and a plurality of optical members 22 (four pieces of diffusion plate, diffusion sheet, lens sheet, and brightness enhancement sheet in order from the bottom). A frame 14 and a plurality (18 in FIG. 1) of cold cathode tubes 23 which are linear light sources accommodated in a case 21 are provided.

[0025] Each optical member 22 is for converting substantially linear light emitted from each cold cathode tube 23 into a surface, and is formed into a rectangular surface larger than the display area of the liquid crystal display device 10. It has been. Each optical member 22 is stacked in the vertical direction and is held in a state where the outer peripheral edge outside the display area is sandwiched between the outer peripheral edge of the case 21 on the back side and the frame-like frame 14 on the front side. It has become so. As described above, in the present embodiment, the knock light 12 includes the optical member 22 integrally.

Here, the cold cathode tube 23 will be described in detail. The cold cathode tube 23 is a kind of discharge tube, and its configuration and light emission principle are generally as follows. The cold cathode tube 23 has a structure in which electrodes are provided at both ends of an elongated substantially cylindrical glass tube sealed with mercury inside, and electrons are ejected by applying an instantaneous high voltage between both electrodes. When the electrons collide with mercury atoms, mercury nuclear ultraviolet rays are emitted, and the ultraviolet rays are converted into visible light by phosphors applied to the inside of the glass tube, and light is emitted. .

Next, the arrangement of the cold cathode tubes 23 will be described in detail. Each cold-cathode tube 23 has its axial direction parallel to the longitudinal direction of case 21 (liquid crystal panel 11). 1 (Liquid crystal panel 11) are arranged along the short direction. The spacing (pitch) between adjacent cold cathode tubes 23 is set to be approximately the same. The alignment direction of the cold cathode tubes 23 is parallel to the surface direction of the liquid crystal panel 11.

[0028] The mounting structure of each cold cathode tube 23 will be described in detail. A substantially central portion of each cold cathode tube 23 in the length direction is supported by a support portion 24 attached to the case 21. On the other hand, holders 25 are attached to both ends of each cold cathode tube 23. The cold cathode tube 23 is held by the support 24 and the holder 25 at a position that is lifted by a predetermined height from the upper surface of the case 21 (the surface facing the liquid crystal panel 11 and the optical member 22). The holder 25 is formed in a substantially rectangular column shape that is elongated along the short side direction of the case 21, and a plurality of insertion holes into which each cold cathode tube 23 can be inserted individually are arranged on the side facing the inside. It is possible to hold all the cold cathode tubes 23 at once. From above the holder 25, holder covers 26 that cover (enclose) the ends of the cold-cathode tubes 23 and the holder 25 are attached to both ends in the long side direction of the case 21. The holder cover 26 includes an accommodation space 26 a that opens downward so that the ends of the holder 25 and the cold cathode tube 23 can be accommodated. Further, on the side facing the inner side of the holder cover 26, an escape groove 26b for allowing each cold cathode tube 23 to escape is formed in communication with the accommodation space 26a.

[0029] Now, the holder 25 described above is held in a state in which it can be displaced in the vertical direction with respect to the holder cover 26, that is, in a direction in which the holder 25 is in contact with or separated from the liquid crystal panel 11, and in association therewith, the cold cathode tube 23 The end of each can be displaced in the same direction. In other words, the holder 25 and the holder cover 26 constitute a movable means for displacing the cold cathode tube 23.

More specifically, guide portions 27 projecting outward are provided in the vicinity of both end portions in the length direction on the outer side surfaces of both holders 25. On the other hand, a guide groove 28 into which the above-described guide portion 27 can be fitted is provided on the side of the holder cover 26 facing outward. The guide groove 28 is configured to open in the vertical direction and outward, and has a height that allows the guide portion 27 to move up and down. The outer surface of the guide part 27 is in sliding contact with the peripheral surface of the guide groove 28, so that the movement operation (vertical movement) of the holder 25 is guided.

[0031] As shown in FIGS. 2 and 3, a pair of holding projections 29 are laterally formed on both side surfaces of the guide portion 27 of one of the holders 25 (right side shown in FIG. 1). Protruding ing. On the other hand, the holding grooves 30 to 32 are formed on the side edges of the guide grooves 28 so that the holding protrusions 29 can be fitted and locked. It is held at the height position. The holding grooves 30 to 32 are arranged in three positions spaced apart from each other in the guide groove 28, and the holding protrusions 29 are selectively fitted to these holding grooves 30 to 32. By doing so, the holder 25 can be held at three different positions up and down.

On the other hand, the support portion 24 includes a fixed portion 33 fixed to the case 21 and a rotating portion 34 pivotally supported so as to be rotatable with respect to the fixed portion 33. The portion 34 includes a pair of elastic pieces that can elastically hold the substantially central portion of the cold cathode tube 23 in the length direction. Accordingly, when the holder 25 having the holding projection 29 moves up and down (front side or back side), the cold cathode tube 23 is displaced in the opposite direction to each other and the entire support portion 24 is moved. Is tilted and displaced in the form of a seesaw. At this time, the end portion of the cold cathode tube 23 and the holder 25 move on an arc-shaped locus centering on the support portion 24. With this movement, the angle formed by the axis of the cold cathode tube 23 with respect to the surface direction of the liquid crystal panel 11 changes.

Specifically, in a state where the holding projection 29 of the holder 25 is locked to the central holding groove 30 among the holding grooves 30 to 32, each cold cathode tube 23 has the axis of the liquid crystal panel 11. It is parallel to the surface direction and supported in a horizontal position as a whole (Fig. 2). When the holding projection 29 is locked to the upper (front side) holding groove 31 among the holding grooves 30 to 32, each cold cathode tube 23 has its axis line as shown in FIG. It is tilted to the right as shown, and is supported in a posture in which the direction of light irradiation is generally tilted to the left (Fig. 4). In the state where the holding projection 29 is locked to the lower (back side) holding groove 32 among the holding grooves 30 to 32, each cold cathode tube 23 has the axis line with respect to the surface direction of the liquid crystal panel 11. It is tilted upward as shown in Fig. 5 and is supported in a posture in which the direction of light irradiation is generally tilted to the right (Figure 5). The central holding groove 30 is formed almost horizontally, whereas the upper and lower holding grooves 31 and 32 are inclined with respect to the surface direction of the liquid crystal panel 11 so as to conform to the attitude of the cold cathode tube 23. Shaped.

An operation portion 35 that projects further outward than the guide portion 27 is provided on the outer side surface of the holder 25 having the holding projection 29. The operation unit 35 is substantially the length direction of the holder 25. It is arranged in the center, and is arranged in a state of being exposed to the outside of the case 21 through a notch formed in the side part of the case 21. Therefore, the user of the liquid crystal display device 10 can manually operate the operation unit 35 with an external force. By operating this operation unit 35 up and down, the end of the holder 25 and the cold cathode tube 23 can be moved up and down, thereby changing the angle formed by the axis of the cold cathode tube 23 with respect to the liquid crystal panel 11. * Adjustable.

The present embodiment has the above-described structure, and the operation thereof will be described next. In the liquid crystal display device 10 configured as described above, in order to display an image on the liquid crystal panel 11, each cold cathode tube 23 of the knocklight 12 is turned on, and each switching is performed by appropriately supplying a signal to each wiring. The element is driven, thereby controlling the alignment state of the liquid crystal 16. As a result, a predetermined image can be displayed on the liquid crystal panel 11.

Here, the light distribution of the backlight 12 at the time of lighting will be described in detail. Each cold-cathode tube 23 is a linear light source, and its individual light distribution is such that the light intensity is greatest in the direction orthogonal to the axial direction, and the light intensity gradually decreases as it approaches the axial direction. (See Figure 11). Therefore, as shown in FIG. 2, when the posture of each cold cathode tube 23 is set to be horizontal along the surface direction of the liquid crystal panel 11, sufficient brightness is obtained when the liquid crystal display device 10 is viewed from the front. However, when viewed obliquely, there is a concern that the brightness may be insufficient due to the above-mentioned bias in the light distribution. In particular, the liquid crystal display device 10 can be seen only by an oblique force due to circumstances such as restrictions on the installation location of the liquid crystal display device 10 and the viewing location of the user! /, In case it was a problem.

In such a case, the posture of each cold cathode tube 23 is changed as follows. Specifically, when the liquid crystal display device 10 is viewed from the left oblique direction shown in FIG. 2, the operation unit 35 is operated upward (front side) shown in FIG. Then, while the outer surface of each guide portion 27 is in sliding contact with the inner peripheral surface of each guide groove 28, the right end of the right holder 25 and each cold-cathode tube 23 is upward, the left holder 25 and each cold-cathode tube The left end of 23 is displaced downward. At this time, the rotating part 34 in the support part 24 rotates with respect to the fixed part 33, so that the entire cold cathode tube 23 is allowed to tilt. Then, by holding the holding projection 29 in the upper holding groove 31, as shown in FIG. 4, each cold-cathode tube 23 is supported in a posture inclined upward to the right. This figure The direction in which the light intensity of each cold-cathode tube 23 is maximized is directed toward the user side, so that even when the liquid crystal display device 10 is viewed in the left oblique direction force shown in FIG. Can be secured.

Conversely, when the liquid crystal display device 10 is viewed from the diagonally right direction shown in FIG. 2, the operation unit 35 is operated downward (back side) shown in FIG. Then, in the same manner as described above, the right side ends of the right holder 25 and the cold cathode tubes 23 are guided downward by the guide portions 27 and the guide grooves 28, and the left side of the left holder 25 and the cold cathode tubes 23. The end is displaced upward. Then, by holding the holding projection 29 in the lower holding groove 31, as shown in FIG. 5, each cold cathode tube 23 is supported in a posture inclined to the left. In this position, the directional force at which the light intensity of each cold-cathode tube 23 is maximized is directed toward the user, so that even when the liquid crystal display device 10 is viewed from the diagonally right direction shown in FIG. Can ensure

As described above, according to the present embodiment, the cold cathode tube 23 can be displaced by the holder 25 so that the angle formed by the axis of the cold cathode tube 23 with respect to the surface direction of the liquid crystal panel 11 is changed. Therefore, even if there are restrictions on the installation location of the liquid crystal display device 10 and the liquid crystal panel 11 can only be seen with a predetermined directional force, the angle of the cold cathode tube 23 can be adjusted according to that direction, Therefore, good display quality can always be obtained regardless of the situation.

[0040] By the way, the display principle of the liquid crystal panel 11 utilizes the alignment characteristics of the liquid crystal molecules. Therefore, a difference in display performance tends to occur depending on the viewing angle of the liquid crystal panel 11. In general, the display performance is most excellent when the liquid crystal panel 11 is viewed from the front, and the display performance tends to deteriorate as the viewing angle increases. However, according to the present embodiment, the cold cathode tube 23 can be displaced independently of the liquid crystal panel 11, so that, for example, when the liquid crystal panel 11 is viewed simultaneously from the front and from the oblique direction, If the cathode tube 23 is tilted in accordance with the above-mentioned oblique direction, good display quality can be obtained even with! / In both directions.

[0041] Since the holder 25 for displacing the cold cathode tube 23 is attached to the end of the cold cathode tube 23, the holder 25 avoids blocking the light emitted from the cold cathode tube 23. Display quality can be kept good.

[0042] Further, the holder cover 26 holds the holder 25 at a plurality of different positions in the vertical direction (direction in which the holder 25 is in contact with and away from the liquid crystal panel 11), and the operation unit 35 provided on the holder 25 can be operated from the outside. Thus, the inclination angle of each cold cathode tube 23 can be easily adjusted manually with an external force.

[0043] In addition, since the substantially central portion in the length direction of the cold cathode tube 23 is supported by the support portion 24, when the cold cathode tube 23 is displaced, it is displaced in a seesaw shape with the support portion 24 as a fulcrum. Is done.

A second embodiment of the present invention will be described with reference to FIGS. Embodiment 2 shows a case where there are a plurality (two) of movable means. In the second embodiment, redundant description of the same structure, operation, and effect as in the first embodiment will be omitted. FIG. 6 shows an example in which the number of cold cathode tubes 23 is six, but the number can be arbitrarily changed.

In the present embodiment, as shown in FIG. 6, the holders 40, 41 attached to the end portions of the cold cathode tubes 23 are the holder 40 connected to the connecting portion 42, the connecting portion 42, and the like. There are two types of holders 40 and 41, a separated holder 41 and the like. Specifically, the connecting portion 42 is arranged on the outer side in the long side direction of the case 21 with respect to the holders 40 and 41, and also in the short side direction of the case 21 (perpendicular to the axial direction of the cold cathode tube 23 and the liquid crystal panel) 11 in a direction parallel to the surface direction). The connecting portions 42 are alternately connected to the holders 40 attached to the end portions of the cold cathode tubes 23. Accordingly, the types of the holders 40, 41 mounted on both ends of each cold cathode tube 23 are different on the left and right sides, and the types of the holders 40, 41 adjacent to each other in the short side direction of the case 21 are the top and bottom shown in FIG. Different settings are used.

[0046] Since the holders 40 and 41 attached to the ends of the adjacent cold cathode tubes 23 are separated from each other in this way, the adjacent cold cathode tubes 23 can be tilted independently of each other. Is done. Further, the connecting portion 42 is provided with an operating portion 43 that protrudes further outward and is exposed outside the case 21. Of the holders 40 connected to the connecting portion 42, the short side direction of the case 21 is Holding guides 29 are respectively provided on the guide portions 27 of the holders 40 arranged at both ends.

Next, the operation of the liquid crystal display device 10 using the holders 40 and 41 having the above-described configuration will be described. For example, when the user views the liquid crystal display device 10 simultaneously from the left and right oblique directions in the figure (specifically, when viewing the liquid crystal display device from the driver seat side and the passenger seat side simultaneously in an in-vehicle liquid crystal display device), By operating 43, as shown in FIG. 7, the cold cathode tube 23 group with the holder 40 connected to one of the connecting portions 42 is tilted about the support portion 24, and is raised to the right. In contrast to the inclined posture, the cold cathode tube 23 group to which the holder 40 connected to the other connecting portion 42 is attached is similarly tilted so as to be inclined to the upper left force ^. As a result, sufficient brightness can be ensured even when viewing from both left and right diagonal directions simultaneously. In the in-vehicle liquid crystal display device, when there is no user in the passenger seat, all the cold cathode tubes 23 may be operated so as to face the driver seat.

[0048] On the other hand, when the liquid crystal display device 10 is viewed simultaneously from the front and diagonally to the left, by operating each operation unit 43, it is connected to one connection unit 42 as shown in FIG. The cold cathode tube 23 group with the holder 40 attached is placed in a horizontal position, while the cold cathode tube 23 group with the holder 40 connected to the other connecting portion 42 is inclined upward to the right. The posture will be changed. As a result, sufficient brightness can be ensured even when viewing from both the front and diagonal directions at the same time. In addition, when the liquid crystal display device 10 is viewed simultaneously from the diagonal direction to the right with frontal force, the cold cathodes corresponding to one of the connecting portions 42 are operated by operating the operating portions 43 in the same manner as shown in FIG. Sufficient brightness can be ensured by setting the tube group 23 in a horizontal posture and the cold cathode tube group 23 corresponding to the other connecting portion 42 in a posture inclined upward to the left.

[0049] As described above, according to the present embodiment, the holders 40 respectively connected to the two connecting portions 42 are attached to the end portions of the cold cathode tubes 23. The liquid crystal panel 11 can be displaced independently of each other, which is more preferable when the liquid crystal panel 11 is viewed simultaneously from different directions.

[0050] Further, since the adjacent cold cathode tubes 23 are connected to different connecting portions 42, the adjacent cold cathode tubes 42 can be displaced independently of each other, and thus the entire liquid crystal panel 11 can be displaced. Even when viewing the images simultaneously from different directions, the brightness of the entire liquid crystal panel 11 is less likely to be uneven.

[0051] <Embodiment 3>

Embodiment 3 of the present invention will be described with reference to FIG. In the third embodiment, the cold cathode tube 23 is automatically displaced by an electric movable means. In the third embodiment, redundant description of the same structure, operation, and effect as in the first embodiment will be omitted.

In the present embodiment, as shown in FIG. 10, a belt 50 is attached to the outer surface of the holder 25 for the purpose of moving the holder 25 up and down. The inner circumferential surface of the belt 50 is provided with teeth aligned in the circumferential direction, and these teeth mesh with the teeth of a pair of gears 51 arranged at positions spaced apart from each other in the vertical direction. The motor shaft 52a of the electric motor 52 is attached to the center of each gear 51, and the gear 51 and the belt 50 rotate in conjunction with the rotation of the electric motor 52 in the forward and reverse directions. As a result, the holder 25 is moved up and down. A pair of the electric movable means is disposed at both end positions in the length direction of the holder 25.

[0053] The electric motor 52 is controlled to be turned on and off and controlled in the forward and reverse rotation directions by a user operating an input unit (not shown). The user can adjust the tilt angle of the cold cathode tube 23 by moving the holder 25 up and down by appropriately operating the input unit. At this time, since the holder 25 is steplessly held at a desired height position by the amount of rotation of the electric motor 52, it is possible to cope with fine adjustment of the inclination angle of the cold cathode tube 23. The input unit receives an infrared signal (signal) from a so-called touch panel type using a touch sensor installed on the screen of the liquid crystal panel 11 or a remote control (transmitter) for remote operation attached to the liquid crystal display device 10. It is possible to adopt either a remote control method using a receiver built in the liquid crystal display device 10 or a button method using a button installed on the outer surface of the liquid crystal display device 10. According to the remote control type, the viewer can displace the cold cathode tube 23 by remote control, which is excellent in convenience.

The present invention is not limited to the embodiments described above with reference to the drawings. For example, the following embodiments are also included in the technical scope of the present invention.

[0055] (1) In the first and second embodiments described above, the holding structure in which the holding protrusion of the holder fits into the holding groove of the holder cover is shown. Conversely, the holding protrusion is held by the holder cover. A groove may be provided. Also, in Embodiments 1 and 2, the force shown in the case of one holding protrusion and three holding grooves up and down is provided. Conversely, three holding protrusions are provided up and down, and one holding groove is provided. Also good. The number of holding protrusions and holding grooves can be arbitrarily changed. For the holder holding structure, apply a mechanism other than the concave / convex fitting between the holding protrusion and holding groove.

[0056] (2) In Embodiment 2 described above, the force shown in the case where the connecting portion is arranged on the outer side in the surface direction of the liquid crystal panel with respect to the holder, for example, the connecting portion is arranged above or below the holder. What is done is also included in the present invention. Specifically, the connecting part has a gate shape that straddles the upper or lower side of the adjacent holder, and the holder adjacent to the portal part is allowed to escape, thereby allowing the holder to move up and down. What should I do!

(3) The connecting portion may be automatically moved by attaching the belt in the electric movable means shown in Embodiment 3 to the connecting portion shown in Embodiment 2. ! In that case, the notch of the operation part and the case can be omitted.

(4) In each of the above-described embodiments, the case where the support portion for the cold cathode tube is configured by the fixed portion and the rotating portion has been shown. It may have a substantially triangular shape with a slope that supports and allows tilting of the cold cathode tube and does not have a rotating part. Further, the support position for the cold cathode tube may be a position other than the central position in the length direction of the cold cathode tube.

[0059] (5) In each of the embodiments described above, the cold cathode tube is displaced by displacing the holder attached to the end of the cold cathode tube, but other than the end of the cold cathode tube. A movable part may be attached to the part, and the movable part may be displaced.

[0060] (6) In Embodiment 2 described above, the case where adjacent cold-cathode tubes are connected to different movable means has been shown. For example, the upper half cold-cathode tube shown in FIG. 6 is used as one movable means. Alternatively, the lower half cold cathode tubes may be connected to the other movable means. In this case, for example, the information displayed on the upper and lower halves of the LCD panel is different, Useful when looking from different directions.

[0061] (7) In each of the above-described embodiments, the present invention includes one having three or more movable means having the force shown in the case where one or two movable means are provided.

(8) In each of the above-described embodiments, an example in which a cold cathode tube is used as the linear light source is illustrated.

In addition to the cold cathode tube, a discharge tube such as a hot cathode tube or a xenon tube can be used. In addition to the discharge tube, the present invention includes a configuration in which a plurality of point light sources such as LEDs are linearly arranged.

(9) In each of the embodiments described above, the present invention can be applied to the case where a display panel of a type other than the liquid crystal panel is used as the display panel.

Claims

The scope of the claims

[1] A linear light source that is arranged on the back side of the display panel and irradiates light toward the display panel, and an angle of the axial force of the linear light source with respect to the surface direction of the display panel changes. An illumination device for a display panel, comprising a movable means for displacing the linear light source.

[2] The first aspect according to claim 1, wherein the movable means includes a movable portion that is attached to an end portion of the linear light source and that displaces the end portion toward and away from the display panel. The illumination device for display panels as described.

[3] A plurality of the linear light sources are provided, a plurality of the movable means are provided, and each movable means is connected to a different linear light source. A lighting device for a display panel according to item 2.

4. The display panel illumination device according to claim 3, wherein the adjacent linear light sources are connected to different movable means.

[5] The movable means includes a holding unit capable of holding the movable unit at a plurality of different positions, and an operation unit connected to the movable unit and operable to move the movable unit from an external cover. The lighting device for a display panel according to any one of claims 2 and 4, which is not defined in claim 2.

[6] The movable means is composed of an electric actuator that moves the movable part and an input part that controls the operation of the electric actuator. 5. The illumination device for a display panel according to any one of items 4.

7. The display panel illumination device according to claim 6, wherein the input unit includes a receiving unit capable of receiving a signal of a transmitter for remote operation.

[8] The display panel according to any one of claims 1 and 7, wherein a support portion for supporting a central portion in the longitudinal direction of the linear light source is provided. Lighting device.

[9] The linear light source is constituted by a discharge tube such as a hot cathode tube, a cold cathode tube, or a xenon tube. Illumination device for display panel as described.

10. The display according to claim 1, wherein the linear light source has a configuration in which a plurality of point light sources are linearly arranged. Lighting equipment for panels.

[11] A display device comprising the display panel illumination device according to any one of claims 1 to 10 and a display panel.

12. The display device according to claim 11, wherein the display panel is configured by a liquid crystal panel in which liquid crystal is sandwiched between a pair of translucent substrates.