WO2012008243A1

WO2012008243A1 - Illumination device, display device and television receiver

Info

Publication number: WO2012008243A1
Application number: PCT/JP2011/063041
Authority: WO
Inventors: 張　志芳
Original assignee: シャープ株式会社
Priority date: 2010-07-14
Filing date: 2011-06-07
Publication date: 2012-01-19

Abstract

Disclosed is a backlighting device (illumination device) (12) comprising: an LED (light source) (17); a light guide member (19) which has an optical input face (19b) onto which light is input from the LED (17); a polygonal mirror (turning reflection body) (22) which reflects light from the LED (17) while rotating (turning), and scans the optical input face (19b) by means of the reflected light; and a control section (25) which, when the optical input face (19b) is divided into a plurality of regions (divided optical input faces (19bS)) in the scanning direction (X-axis direction) of the reflected light from the polygonal mirror (22), controls the light emission state of the LED (17) in a time-divided manner corresponding to the scanning period of the reflected light for each region.

Description

Lighting device, display device, and television receiver

The present invention relates to a lighting device, a display device, and a television receiver.

In recent years, the display elements of image display devices such as television receivers are shifting from conventional cathode ray tubes to thin display panels such as liquid crystal panels and plasma display panels, which enables thinning of image display devices. Since the liquid crystal panel used for the liquid crystal display device does not emit light by itself, a backlight device is separately required as a lighting device, and the backlight device is roughly classified into a direct type and an edge light type according to the mechanism. In order to further reduce the thickness of the liquid crystal display device, it is preferable to use an edge light type backlight device, and an example described in Patent Document 1 below is known.

JP 2001-92370 A

(Problems to be solved by the invention)
What is described in the above-mentioned Patent Document 1 includes a large number of light sources arranged in parallel to the end of the backlight device, and a light guide plate that guides light from each light source and emits it toward the liquid crystal panel side. By adjusting the light emission state of each light source individually, the amount of light emitted from each region of the light guide plate divided in correspondence with each light source is controlled. However, in this case, since it is necessary to arrange a large number of light sources in parallel along the light incident surface, there is a problem that the cost related to the light sources tends to be high. It was a problem.

The present invention has been completed based on the above circumstances, and aims to reduce costs.

(Means for solving problems)
The illumination device according to the present invention includes a light source, a light guide member having a light incident surface on which light from the light source is incident, and the light incident surface that reflects light from the light source while being rotated. And the light incident surface is divided into a plurality of regions in the scanning direction by the reflected light from the rotating reflector, and is associated with the scanning period of the reflected light for each region. A control unit that controls the light emission state of the light source in a time-sharing manner.

In this way, the light emitted from the light source is reflected by the rotating reflector and then enters the light incident surface of the light guide member. Here, since the rotating reflector reflects light from the light source while being rotated, the light incident surface can be scanned by the reflected light. Then, the control unit controls the light emission state of the light source in a time-sharing manner in association with the scanning period of the reflected light for each region on the light incident surface divided in the scanning direction by the reflected light, thereby reflecting the reflected light for each region. It is possible to individually adjust the amount of incident light. Therefore, according to the present invention, it is possible to reduce the number of light sources used, compared to a conventional arrangement in which a large number of light sources are arranged in parallel and the light emission state of each light source is individually adjusted. Costs related to the light source can be reduced.

The following configuration is preferable as an embodiment of the present invention.
(1) The alignment direction of the light source and the rotating reflector and the alignment direction of the rotating reflector and the light guide member are substantially orthogonal to each other. If it does in this way, compared with the case where a light source, a rotation reflector, and a light guide member are all located in a line, the whole illuminating device can be kept small.

(2) The rotating reflector is disposed at a substantially central position of the light incident surface in the scanning direction. In this way, among the light reflected by the rotating reflector, the light path lengths of the light reaching one end of the light incident surface and the light reaching the other end in the scanning direction are substantially equal. Become. Therefore, for example, it is possible to obtain an effect that it is easy to set the scanning period of each region of the light incident surface by the reflected light from the rotating reflector.

(3) The light source is disposed on an end side of the light incident surface in the scanning direction. In this case, compared to a case where the light source is arranged on the center side of the light incident surface in the scanning direction, it is possible to obtain an effect such as easy connection of wiring to the light source.

(4) The plurality of regions on the light incident surface are partitioned so that the dimensions in the scanning direction are substantially the same. In this way, the scanning period of the reflected light from the rotating reflector for each region can be made substantially the same, so that the control by the control unit becomes easier.

(5) The rotating reflector is constituted by a polygon mirror that rotates in one direction. In this way, each region on the light incident surface can be scanned by the reflected light from the polygon mirror rotating in one direction, which is particularly suitable for scanning the light incident surface at high speed.

(6) The polygonal mirror has a regular polygonal shape when viewed from the direction along the rotation axis. In this way, the surfaces that reflect the light from the light source are all uniform in size. For example, if the rotation speed of the polygon mirror is constant, the scanning range for the light incident surface per unit time is constant. be able to.

(7) The polygonal mirror has a square shape when viewed from the direction along the rotation axis. In this way, it is possible to set the angle range in which light from the light source can be reflected to approximately 180 degrees. Therefore, it is particularly suitable when the light incident surface of the light guide member is large in the scanning direction, and the degree of freedom of arrangement in the polygon mirror in the illumination device is increased.

(8) A condensing member that is interposed between the light source and the rotating reflector and condenses light from the light source and emits the light toward the rotating reflector. In this way, the light emitted from the light source can be efficiently supplied to the rotating reflector. Thereby, the light from the light source can be incident on the light incident surface of the light guide member without waste, and the utilization efficiency can be improved, so that the luminance can be improved and the power consumption can be reduced.

(9) The light source, the condensing member, and the rotating reflector are arranged in a straight line, the alignment direction of the light source, the condensing member, and the rotating reflector, and the rotating reflection. The body and the arrangement direction of the light guide members are substantially orthogonal to each other. If it does in this way, compared with the case where a light source, a condensing member, a rotation reflector, and a light guide member are all located in a line, the whole illuminating device can be kept small.

(10) The light condensing member condenses light from the light source so that a traveling direction of light emitted toward the rotating reflector is parallel to the light incident surface. If it does in this way, the light parallel to a light-incidence surface can be appropriately incident on each area | region in a light-incidence surface by reflecting and turning an angle | corner with a rotation reflector.

(11) The light condensing member is disposed in a position near the light source relative to the rotating reflector. In this way, the light emitted from the light source can be collected more efficiently.

(12) The control unit blinks the light source periodically to change the time ratio between the lighting period and the extinguishing period. In this way, the light emission state of the light source is controlled by a so-called PWM (Pulse Width Modulation) method, so that the voltage value applied to the light source can be made constant, and the circuit configuration related to the control can be changed. It can be made simple, and a light control range can be secured sufficiently large, and the light emission state of the light source can be controlled more appropriately.

(13) The light guide member includes a plurality of divided light guide members divided for each of the plurality of regions on the light incident surface. If it does in this way, the light which injected into each area | region in a light-incidence surface can be made to radiate | emit, after being individually guided by each division | segmentation light guide member.

(14) A low refractive index layer having a refractive index relatively lower than that of the divided light guide member is interposed between the adjacent divided light guide members. If it does in this way, since it will become difficult to radiate | emit the light in a division | segmentation light guide member to the low-refractive-index layer side, it can prevent that light crosses between adjacent division | segmentation light guide members, and an adjacent division | segmentation light guide member The optical independence can be ensured. In addition, it is possible to secure a sufficient amount of light emitted from each divided light guide member and improve luminance.

(15) The low refractive index layer is an air layer. This eliminates the need for a special member for forming the low refractive index layer, and thus can cope with low cost.

(16) The light source is an LED. In this way, high brightness and low power consumption can be achieved.

Next, in order to solve the above problem, a display device of the present invention includes the above-described illumination device and a display panel that performs display using light from the illumination device.

According to such a display device, since the lighting device that supplies light to the display panel has a reduced number of light sources used, it is possible to reduce manufacturing costs.

A liquid crystal panel can be exemplified as the display panel. Such a display device can be applied as a liquid crystal display device to various uses such as a display of a television or a personal computer, and is particularly suitable for a large screen.

(The invention's effect)
According to the present invention, cost reduction and the like can be achieved.

1 is an exploded perspective view showing a schematic configuration of a television receiver according to Embodiment 1 of the present invention. The exploded perspective view which shows schematic structure of the liquid crystal display device with which a television receiver is equipped The top view which shows the arrangement structure of the chassis in the backlight apparatus with which a liquid crystal display device is equipped, the light guide member, and the light source unit. Sectional view taken along line iv-iv in FIG. V-v sectional view of FIG. Block diagram for explaining LED drive control The top view for demonstrating operation | movement of a light source unit, Comprising: The reflected light injects into the 1st division | segmentation light incident surface The top view for demonstrating operation | movement of a light source unit, Comprising: The reflected light injects into the 3rd division | segmentation light incident surface The top view for demonstrating operation | movement of a light source unit, Comprising: The reflected light injects into the 6th division | segmentation light entrance surface The top view for demonstrating operation | movement of a light source unit, Comprising: The reflected light injects into the 8th division | segmentation light incident surface The top view for demonstrating operation | movement of a light source unit, Comprising: The reflected light is irradiated to the synchronous detection part An enlarged plan view for explaining an operation of the light source unit and showing a process in which the reflected light scans the fourth split light incident surface. The top view which shows the arrangement configuration of the chassis in the backlight apparatus which concerns on Embodiment 2 of this invention, the light guide member, and the light source unit. The top view which shows the arrangement configuration of the chassis in the backlight apparatus which concerns on Embodiment 3 of this invention, a light guide member, and a light source unit. The top view which shows the arrangement configuration of the chassis in the backlight apparatus which concerns on Embodiment 4 of this invention, a light guide member, and a light source unit. The top view which shows the arrangement configuration of the light source unit which concerns on Embodiment 5 of this invention. The top view which shows the arrangement configuration of the chassis in the backlight apparatus which concerns on other embodiment (1) of this invention, a light guide member, and a light source unit. The top view which shows the arrangement configuration of the light source unit which concerns on other embodiment (2) of this invention.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the liquid crystal display device 10 is illustrated. In addition, a part of each drawing shows an X axis, a Y axis, and a Z axis, and each axis direction is drawn to be a direction shown in each drawing. Moreover, let the upper side shown in FIG.4 and FIG.5 be a front side, and let the lower side of the figure be a back side.

As shown in FIG. 1, the television receiver TV according to the present embodiment includes a liquid crystal display device 10, front and back cabinets Ca and Cb that are accommodated so as to sandwich the liquid crystal display device 10, a power source P, a tuner T, And a stand S. The liquid crystal display device (display device) 10 has a horizontally long (longitudinal) square shape as a whole and is accommodated in a vertically placed state. As shown in FIG. 2, the liquid crystal display device 10 includes a liquid crystal panel 11 that is a display panel and a backlight device (illumination device) 12 that is an external light source, which are integrated by a frame-like bezel 13 or the like. Is supposed to be retained.

As shown in FIG. 2, the liquid crystal panel 11 has a horizontally long (longitudinal) rectangular shape in a plan view, and a pair of glass substrates are bonded together with a predetermined gap therebetween, and between the two glass substrates. The liquid crystal is sealed. One glass substrate is provided with a switching element (for example, TFT) connected to a source wiring and a gate wiring orthogonal to each other, a pixel electrode connected to the switching element, an alignment film, and the like. The substrate is provided with a color filter and counter electrodes in which colored portions such as R (red), G (green), and B (blue) are arranged in a predetermined arrangement, and an alignment film. The liquid crystal panel 11 is connected to a control board (not shown) with a liquid crystal driving driver for supplying a driving signal to each source wiring and each gate wiring. The driving is controlled by the liquid crystal panel control unit 26 (FIG. 6). The liquid crystal panel control unit 26 displays, for example, 60 or 120 display images on the liquid crystal panel 11 per second. A polarizing plate is disposed on the outside of both substrates.

As shown in FIG. 2, the backlight device 12 covers a substantially box-shaped chassis 14 having an opening that opens toward the light emission surface side (the liquid crystal panel 11 side), and covers the opening of the chassis 14. The optical member 15 group (diffusing plate (light diffusing member) 15a and a plurality of optical sheets 15b arranged between the diffusing plate 15a and the liquid crystal panel 11) is provided. Further, in the chassis 14, a light source unit U, which will be described in detail later, a light guide member 19 that guides light from the light source unit U and guides it to the optical member 15 (liquid crystal panel 11), and a light guide member 19 are provided. And a frame 16 that is pressed from the front side. The backlight device 12 is of a so-called edge light type (side light type) in which the light source unit U is arranged opposite to one end of the light guide member 19 on the long side. Below, each component of the backlight apparatus 12 is demonstrated in detail.

The chassis 14 is made of a metal plate material (sheet metal made of iron, aluminum, or the like), and has a shallow box shape as a whole as shown in FIGS. Specifically, the chassis 14 includes a bottom plate 14a that has a horizontally-long rectangular shape like the liquid crystal panel 11, a pair of long side plates 14b that rise from outer ends on the long side of the bottom plate 14a, and a short side of the bottom plate 14a. And a pair of side plates 14c on the short side that rise from the outer ends of the side. The long side direction of the chassis 14 (bottom plate 14a) coincides with the X-axis direction (horizontal direction), and the short side direction coincides with the Y-axis direction (vertical direction). The frame 16 and the bezel 13 can be screwed to the long side plate 14b.

As shown in FIG. 2, the optical member 15 has a horizontally long rectangular shape when viewed in a plane, like the liquid crystal panel 11 and the chassis 14. The optical member 15 is placed on the front side (light emitting side) of the light guide member 19 and is disposed between the liquid crystal panel 11 and the light guide member 19. The optical member 15 includes a diffusion plate 15a disposed on the back side (light guide member 19 side, opposite to the light emitting side) and an optical sheet 15b disposed on the front side (liquid crystal panel 11 side, light emitting side). Composed. The diffusing plate 15a has a structure in which a large number of diffusing particles are dispersed in a substantially transparent resin-made base material having a predetermined thickness, and has a function of diffusing transmitted light. The optical sheet 15b has a sheet shape that is thinner than the diffusion plate 15a, and three optical sheets are laminated. Specific types of the optical sheet 15b include, for example, a diffusion sheet, a lens sheet, a reflective polarizing sheet, and the like, which can be appropriately selected and used.

As shown in FIG. 2, the frame 16 is formed in a frame shape (frame shape) extending along the outer peripheral end portion of the light guide member 19, and the outer peripheral end portion of the light guide member 19 extends over substantially the entire circumference. It can be pressed from the front side. Of the pair of long side portions in the frame 16, the long side portion on the light source unit U side (left side shown in FIG. 4) is formed wider than the other long side portion as shown in FIG. ing. Further, the frame 16 can receive the outer peripheral end of the liquid crystal panel 11 from the back side. As for the bezel 13, the long side portion on the light source unit U side has a wide shape like the above-described frame 16 (FIGS. 2 and 4).

The overall structure of the light guide member 19 will be described. The light guide member 19 is made of a synthetic resin material (for example, acrylic) having a refractive index sufficiently higher than that of air and substantially transparent (exceeding translucency). As shown in FIG. 2, the light guide member 19 is formed in a plate shape having a horizontally long rectangular shape when viewed in a plane, as in the case of the liquid crystal panel 11 and the chassis 14, and the entire long side direction is the X-axis direction. In addition, the entire short side direction coincides with the Y-axis direction, and the plate thickness direction orthogonal to the main plate surface coincides with the Z-axis direction. As shown in FIG. 4, the light guide member 19 is disposed in the chassis 14 at a position directly below the liquid crystal panel 11 and the optical member 15, and the light source unit U is opposed to one end thereof. Accordingly, the alignment direction of the optical member 15 (liquid crystal panel 11) and the light guide member 19 matches the Z-axis direction, while the alignment direction of the light source unit U and the light guide member 19 matches the Y-axis direction. Both the alignment directions are orthogonal to each other. The light guide member 19 introduces light from the LED 17 included in the light source unit U, and has a function of rising and emitting the light toward the optical member 15 side (Z-axis direction) while propagating the light inside. .

As shown in FIG. 2, the light guide member 19 has a substantially flat plate shape that extends along the bottom plate 14a of the chassis 14 and the plate surfaces of the optical member 15 as a whole. It is assumed to be parallel to the Y-axis direction. Of the main plate surface of the light guide member 19, the surface facing the front side is a light emission surface 19 a that emits internal light toward the optical member 15 and the liquid crystal panel 11 as shown in FIG. 4. Of the outer peripheral end surfaces adjacent to the main plate surface of the light guide member 19, the end surface on the long side and facing the light source unit U is a light incident surface 19 b on which light from the light source unit U is incident. The light incident surface 19b as a whole is a long surface in which the long side direction coincides with the X-axis direction and the short side direction coincides with the Z-axis direction, and is a surface substantially orthogonal to the light emitting surface 19a. The

On the surface 19c opposite to the light exit surface 19a of the light guide member 19, a light guide reflection sheet 20 capable of reflecting the light in the light guide member 19 and rising up to the front side covers the entire area. Is provided. In other words, the light guide reflection sheet 20 is disposed between the bottom plate 14 a of the chassis 14 and the light guide member 19. Note that at least one of the light exit surface 19a and the opposite surface 19c of the light guide member 19 has a reflecting portion (not shown) that reflects internal light or a scattering portion that scatters internal light (see FIG. (Not shown) is patterned so as to have a predetermined in-plane distribution, and thereby, the emitted light from the light emitting surface 19a is controlled to have a uniform distribution in the surface.

The light guide member 19 having the entire structure as described above is divided into a plurality of parts as shown in FIGS. 3 and 5, and accordingly, the light incident surface 19a and the light emitting surface 19b are also divided into a plurality. It is divided. Hereinafter, the divided light guide member 19 is referred to as a “divided light guide member”, and the divided light incident surface 19a and the light output surface 19b are referred to as “divided light incident surface” and “divided light output surface”. And the suffix “S” is attached to each symbol. Specifically, each divided light guide member 19S is divided into eight parts in the long side direction (X axis direction) in such a manner that the light guide member 19 is divided along the short side direction (Y axis direction). Therefore, the divided widths (dimensions along the scanning direction to be described later) are substantially equal. Each divided light guide member 19 </ b> S has a long side dimension that coincides with an overall short side dimension of the light guide member 19, whereas a short side dimension (a dimension along a scanning direction described later) has a light guide member 19. About 1/8 of the entire long side dimension. There is a slight gap between the adjacent divided light guide members 19S, which is an air layer AS having a relatively lower refractive index than each of the divided light guide members 19S. The light emitting surface 19a and the light incident surface 19b are divided into a plurality of regions for each divided light guide member 19S in the X-axis direction, and the divided regions are divided light emitting surfaces 19aS and divided light incident surfaces 19bS. It is said. In other words, each of the divided light guide members 19S has a divided light emitting surface 19aS and a divided light incident surface 19bS individually, and the divided light emitting surfaces 19aS are arranged in a single plane so that the entire light can be obtained. The exit surface 19a is configured, and the divided light incident surfaces 19bS are arranged in a single plane, so that the entire light incident surface 19b is configured. The divided light exit surfaces 19aS have substantially the same area. Similarly, the divided light incident surfaces 19bS have substantially the same area.

In the following, when distinguishing each divided light guide member 19S, each divided light emitting surface 19aS, and each divided light incident surface 19bS, the one at the left end shown in FIG. 3 (the one closest to the LED 17) is “first”. The subscript “A” is attached to each symbol, and the right side of the symbol is designated as “second”, “third”..., And the subscript “B”, “C”,. Each of the symbols is attached with a suffix “H” as “eighth” with the one at the right end of the figure (the one farthest from the LED 17). Specifically, the first divided light guide member 19SA to the eighth divided light guide member 19SH respectively include the first divided light incident surface 19aSA to the eighth divided light incident surface 19aSH and the first divided light output surface 19bSA to the eighth. Each has a divided light exit surface 19bSH. In addition, when each division | segmentation light guide member 19S, each division | segmentation light emission surface 19aS, and each division | segmentation light entrance surface 19bS are named generically without distinguishing, a subscript shall not be attached | subjected to each code | symbol.

Subsequently, the light source unit U will be described in detail. 2 and 3, the light source unit U emits an LED (Light Emitting Diode) 17 as a light source, an LED substrate 18 on which the LED 17 is mounted, and the light from the LED 17 while condensing the light. A condenser lens 21 to be reflected, a polygon mirror 22 that reflects light from the condenser lens 21 toward the light guide member 19, and a synchronization detection unit 23 that synchronizes the light emission state of the LED 17 with the rotation state of the polygon mirror 22. It is composed of

3 and 4, the LED 17 has a configuration in which an LED chip is sealed with a resin material on a substrate portion fixed to the LED substrate 18. The LED chip mounted on the substrate unit has one main emission wavelength, and specifically, one that emits blue light in a single color is used. On the other hand, the resin material that seals the LED chip is dispersed and blended with a phosphor that emits a predetermined color when excited by the blue light emitted from the LED chip, and generally emits white light as a whole. It is said. In addition, as the phosphor, for example, a yellow phosphor that emits yellow light, a green phosphor that emits green light, and a red phosphor that emits red light are used in appropriate combination, or any one of them is used. It can be used alone. The LED 17 is a so-called top type in which a surface opposite to the mounting surface with respect to the LED substrate 18 is a light emitting surface. The LED 17 has a light distribution such that the optical axis of the emitted light, that is, the traveling direction of light having the highest emission intensity coincides with the X-axis direction.

The LED substrate 18 has a plate shape made of synthetic resin (such as glass epoxy resin), and has a white surface with excellent light reflectivity. As shown in FIG. 3, the LED board 18 has its main plate surface parallel to the Y-axis direction and the Z-axis direction, that is, orthogonal to the main plate surfaces of the liquid crystal panel 11 and the light guide member 19 (optical member 15). It is accommodated in the chassis 14 in a posture. The LED board 18 is fixed to the left side plate 14b shown in FIG. 3 among the side plates 14c on the short side of the chassis 14 by screws or the like. The LED substrate 18 is disposed at a position spaced apart from the light incident surface 19b of the light guide member 19 in the side plate 14c on the short side. A wiring pattern (not shown) made of a metal film (copper foil or the like) is formed on the mounting surface of the LED 17 on the LED substrate 18, and terminal portions formed at the ends of the wiring pattern will be described later. By being connected to the external LED driving unit 24, driving power is supplied to the LED 17. In addition, by attaching the LED board 18 to the side plate 14c arranged at the end of the chassis 14, it is possible to easily secure a wiring path to the LED driving unit 24.

As shown in FIG. 3, the condenser lens 21 is interposed between the LED 17 and a polygon mirror 22 described below, and is disposed relatively closer to the LED 17 than the polygon mirror 22. Specifically, the condensing lens 21 is arranged at a position facing the first divided light incident surface 19bSA of the first divided light guide member 19SA closest to the LED 17 among the light guide members 19 with a predetermined interval. Has been. The condensing lens 21 as a whole is formed in a semi-doughnut shape in plan view, and the surface on the LED 17 side (surface on the light incident side) forms a concave curved surface and the surface on the polygon mirror 22 side (light emission). Side surface) is a convex curved surface. The condensing lens 21 can emit the light emitted from the LED 17 while condensing the light, and the emitted light travels substantially straight along the X-axis direction (parallel to the light incident surface 19b). At the same time, the optical design is such that it hits the polygon mirror 22. Specifically, the light emitted from the LED 17 includes not only those with the highest emission intensity that travel along the X-axis direction, which is the optical axis, but also those that travel in a direction inclined with respect to the optical axis. However, the light traveling in the direction inclined with respect to the optical axis is refracted or reflected in the process of passing through the condenser lens 21, so that the light travels substantially straight along the optical axis and hits the polygon mirror 22. Can be converted to light. Of the light emitted from the LED 17, the light having the highest emission intensity that travels along the X-axis direction, which is the optical axis, is hardly affected by refraction even when transmitted through the condenser lens 21. It is assumed that the lens travels straight along the optical axis as it is.

As shown in FIG. 3, the polygon mirror 22 has an X-axis direction with respect to the condenser lens 21, that is, in the traveling direction of the emitted light from the condenser lens 21, more than the distance between the condenser lens 21 and the LED 17. They are placed at relatively wide positions. That is, the polygon mirror 22 is arranged linearly along the X-axis direction with respect to the LED 17 and the condenser lens 21. The polygon mirror 22 is disposed at a substantially central position with respect to the light guide member 19 in the entire long side direction (the parallel direction of the divided light guide members 19S, the X-axis direction). The polygon mirror 22 is rotatable in one direction around the rotation axis 22a and reflects the light from the condenser lens 21, thereby scanning the light incident surface 19b of the light guide member 19 with the reflected light. It is possible to do.

Specifically, the polygon mirror 22 has a square shape when viewed from the direction along the rotation axis 22a (Z-axis direction), and four flat reflecting surfaces 22b are formed adjacent to each other on the outer peripheral surface thereof. (FIGS. 7 to 12). The reflecting surfaces 22b are equal in area and dimensions. The angle formed by the adjacent reflecting surfaces 22b is 90 degrees. The polygon mirror 22 is driven by an electromagnetic motor (not shown) so as to rotate at a constant rotational speed (angular speed) in the clockwise direction (arrow line direction) shown in FIG. It has become. As the polygon mirror 22 rotates, the angle of each reflecting surface 22b with respect to the light from the condenser lens 21 toward the polygon mirror 22 changes in a time-division manner, and the light reflected by the reflecting surface 22b The traveling direction changes in a time-sharing manner. Specifically, since the polygonal mirror 22 has a square planar shape, the traveling direction of the light (reflected light) reflected by the reflecting surface 22 b is the traveling direction of the light from the condenser lens 21 toward the polygon mirror 22. The angle formed with respect to the angle can be changed in the range of 0 to 180 degrees (angle range of 180 degrees). Accordingly, the reflected light from the polygon mirror 22 is directed from the left side to the right side shown in FIG. 3 along the long side direction (X-axis direction) of the light incident surface 19b of the light guide member 19 as the polygon mirror 22 rotates. It is possible to scan linearly. Specifically, the reflected light is transmitted from the left end shown in FIG. 3 on the first light incident surface 19bSA of the first divided light guide member 19SA to FIG. 3 on the eighth light incident surface 19bSH of the eighth divided light guide member 19SH. It can be continuously scanned over the entire area up to the right end shown. The rotation speed of the polygon mirror 22 is such that the time it takes for the reflected light to scan from the left end of the first light incident surface 19bSA shown in FIG. 3 to the right end of the eighth light incident surface 19bSH shown in FIG. The display period of one display image on the panel 11 is set to coincide with, for example, 1/60 seconds, 1/120 seconds, or the like. Further, the time for scanning the divided light incident surface 19bS of each divided light guide member 19S with reflected light (one scanning period of reflected light with respect to the divided light incident surface 19bS) is the display period of one display image on the liquid crystal panel 11 ( For example, about 1/8 of 1/60 seconds, 1/120 seconds, etc.). The polygon mirror 22 and the light guide member 19 are arranged along the Y-axis direction, and the arrangement direction is orthogonal to the X-axis direction that is the arrangement direction of the LED 17, the condenser lens 21, and the polygon mirror 22. There is a relationship.

As shown in FIG. 3, the synchronization detection unit 23 is attached to the side plate 14 c of the chassis 14 to which the LED board 18 is attached. The synchronization detection unit 23 is located between the LED substrate 18 and the light guide member 19 and can receive the reflected light from the polygon mirror 22. The synchronization detection unit 23 has a built-in optical sensor (not shown) that can detect light, and can detect reflected light from the polygon mirror 22. The synchronization detection unit 23 is connected to a control unit 25 described below, and can output a detection signal toward the control unit 25 when detecting reflected light from the polygon mirror 22. Subsequently, drive control of the control unit 25 and the LED 17 will be described in detail.

As shown in FIG. 6, the control unit 25 can output a signal to the LED drive unit 24 based on the detection signal from the synchronization detection unit 23 to control the drive of the LED 17. Specifically, when the detection signal is input from the synchronization detection unit 23, the control unit 25 refers to information on the rotation speed of the polygon mirror 22 and outputs a signal related to the control to the LED drive unit 24 to obtain a predetermined signal. The light emission state of the LED 17 can be controlled at the timing. At this time, the control unit 25 can control the light emission state of the LED 17 in a time-sharing manner for each scanning period with respect to each split light incident surface 19bS by reflected light.

Specifically, the control unit 25 changes the time ratio between the lighting period and the extinguishing period by periodically blinking the LED 17 while keeping the voltage value applied to the LED 17 constant, so-called PWM (Pulse Width Modulation: pulse). The light emission state of the LED 17 is controlled by the (width modulation) method, and the time ratio between the lighting period and the extinction period in one scanning period with respect to the divided light incident surface 19bS by the reflected light is scanned with respect to each divided light incident surface 19bS. It can be set individually for each period. Note that the amount of light incident on the split light incident surface 19bS during the one scanning period is uniquely determined by the time ratio between the lighting period and the extinguishing period because the voltage value applied to the LED 17 is constant. . Therefore, the control unit 25 can freely set the amount of incident light on each divided light incident surface 19bS individually. For example, the amount of incident light on each divided light incident surface 19bS can be all the same or different. it can. A signal related to a display image is input to the control unit 25 from a liquid crystal panel control unit 26 that controls driving of the liquid crystal panel 11. Therefore, the control unit 25 can control the light emission state of the LED 17 based on the luminance information of the display image. Specifically, the control unit 25 divides the display image into eight divided display areas (divided light emission surfaces 19aS) shared by the divided light guide members 19S, and converts the display image into each divided display area. The required luminance is calculated, and based on the calculated luminance information, the light emission state of the LED 17 is controlled in a time-sharing manner for each scanning period with respect to each divided light incident surface 19bS.

This embodiment has the structure as described above, and its operation will be described next. When the power supply of the liquid crystal display device 10 configured as described above is turned on, the liquid crystal panel control unit 26 controls the driving of the liquid crystal panel 11 and the light from the light source unit U is incident on the light incident surface of the light guide member 19. The light enters the liquid crystal panel 11 by being incident on the liquid crystal panel 11 after being incident on the light 19b and propagating through the optical member 15, and is emitted toward the liquid crystal panel 11. Thus, a predetermined image is displayed on the liquid crystal panel 11. Is displayed. Hereinafter, the operation of the backlight device 12 will be described in detail.

When the power is turned on, the LED 17 is turned on by the LED driving unit 25 based on a signal from the control unit 25 constituting the light source unit U (FIG. 6), and the polygon mirror 22 is driven by driving the electromagnetic motor. It is rotated around the rotation axis 22a at a constant rotation speed. As shown in FIG. 3, the light from the LED 17 is condensed by the condenser lens 21, becomes light that goes straight along the X-axis direction, and is emitted toward the polygon mirror 22. Is reflected in a state where a predetermined angle is given. The light reflected by the polygon mirror 22 can scan the light incident surface 19b of the light guide member 19 over the entire length in the X-axis direction. Specifically, as shown in FIGS. 7 to 10, the reflected light from the polygon mirror 22 scanned from the left end to the right end of the first divided light incident surface 19bSA of the first divided light guide member 19SA. Thereafter, the second divided light incident surface 19bSB of the second divided light guide member 19SB on the right side, the third divided light incident surface 19bSC... Of the third divided light guide member 19SC are scanned in this order, and the eighth divided light guide is obtained. After the eighth divided light incident surface 19bSH of the optical member 19SH is scanned, the first divided light incident surface 19bSA of the first divided light guide member 19SA is scanned again. Note that the time required for scanning all the divided light incident surfaces 19bS by reflected light by setting the rotational speed of the polygon mirror 22 is the display period of one display image on the liquid crystal panel 11 (for example, 1/60 seconds). , 1/120 seconds, etc.). The light emission state of the LED 17 is controlled by the control unit 25 so as to be synchronized with the rotation state of the polygon mirror 22 and the display image displayed on the liquid crystal panel 11.

Specifically, the light reflected by the reflecting surface 22b of the polygon mirror 22 includes what is irradiated on the synchronization detecting unit 23 as shown in FIG. 11 in addition to the light incident on the light incident surface 19b. Therefore, based on the detection of the reflected light from the polygon mirror 22 by the synchronization detection unit 23 and the output of the detection signal to the control unit 25, the control unit 25 changes the rotation state of the polygon mirror 22. The light emission state of the LED 17 can be synchronized. That is, the control unit 25 scans the light incident surface 19b of the light guide member 19 by the reflected light of the polygon mirror 22 based on the timing at which the detection signal is received from the synchronization detection unit 23 and information on the rotational speed of the polygon mirror 22. Therefore, the light emission state of the LED 17 can be controlled in a time-sharing manner for each scanning period in which the reflected light scans each split light incident surface 19bS. As shown in FIG. 12, this scanning period means the divided light from the scanning start position (indicated by the one-dot chain line in FIG. 12) where the reflected light is applied to the left end of the divided light incident surface 19bS of the divided light guide member 19S. This is the time required to reach the scanning end position (indicated by the two-dot chain line in the figure) irradiated on the right end of the figure on the incident surface 19bS. In the control unit 25, it is preferable to perform control such that the LED 17 is turned off during a period in which the reflected light can scan the air layer AS existing between the divided light incident surfaces 19bS.

And the control part 25 is controlling the light emission state of LED17 based on the signal which concerns on the display image from the liquid crystal panel control part 26 which controls the drive of the liquid crystal panel 11, as shown in FIG. Specifically, the control unit 25 determines the luminance required for each divided display region (each divided light emitting surface 19aS) shared by each divided light guide member 19S from the signal related to the display image input from the liquid crystal panel 11. Based on the calculated luminance information, the light emission state of the LED 17 is controlled in a time-sharing manner for each scanning period with respect to each divided light incident surface 19bS. The specific drive control of the LED 17 will be described. The control unit 25 determines the time ratio between the lighting period and the extinguishing period of the LED 17 for each scanning period with respect to each divided light incident surface 19bS, and the luminance of each divided light guide member 19S. The LED 17 is driven and controlled in a time-sharing manner while being determined based on the information. For example, with respect to the scanning period of the divided light incident surface 19bS of the divided light guide member 19S that shares a relatively dark divided display area, the incident light quantity is relatively reduced by relatively shortening the lighting period and lengthening the extinguishing period. On the other hand, with respect to the scanning period of the divided light incident surface 19bS of the divided light guide member 19S that shares a relatively bright divided display area, the incident light quantity is increased by relatively increasing the lighting period and shortening the extinction period. The light emission state of the LED 17 is controlled in a time-sharing manner for each scanning period so as to relatively increase the number of. As a result, the amount of incident light on the divided light incident surface 19bS of each divided light guide member 19S can be individually adjusted, and the amount of incident light can be made appropriate based on the luminance information of the display image. The light incident on each split light incident surface 19bS is reflected by the light guide reflection sheet 20 or totally reflected at the interface with the air layer AS, so that each split can be performed efficiently without leaking to the outside. After propagating through the light guide member 19S, the light is emitted from the split light exit surface 19aS. The emitted light from each divided light exit surface 19aS irradiates each divided display area in the liquid crystal panel 11, while the emitted light amount is substantially equal to the incident light amount to each divided light incident surface 19bS. Because of this relationship, the contrast ratio of the display image can be increased.

As described above, the backlight device (illumination device) 12 of the present embodiment includes the LED (light source) 17, the light guide member 19 having the light incident surface 19 b on which the light from the LED 17 is incident, and the rotation (rotation). ) While reflecting the light from the LED 17 and scanning the light incident surface 19b by the reflected light, and the scanning direction (X) of the light incident surface 19b by the reflected light from the polygon mirror 22 When divided into a plurality of regions (divided light incident surface 19bS) in the axial direction, a control unit 25 is provided that controls the light emission state of the LED 17 in a time-sharing manner in association with the scanning period of the reflected light for each region.

In this way, the light emitted from the LED 17 is reflected by the polygon mirror 22 and then enters the light incident surface 19 b of the light guide member 19. Here, since the polygon mirror 22 reflects the light from the LED 17 while being rotated (turned), the light incident surface 19b can be scanned by the reflected light. Then, the control unit 25 controls the light emission state of the LED 17 in a time-sharing manner in association with the scanning period of the reflected light with respect to each region (divided light incident surface 19bS) on the light incident surface 19b divided in the scanning direction by the reflected light. This makes it possible to individually adjust the amount of reflected light incident on each region. Therefore, according to the present embodiment, the number of LEDs 17 used can be reduced compared to a conventional arrangement in which a large number of LEDs are arranged in parallel and the light emission state of each LED is individually adjusted. For example, the cost related to the LED 17 can be reduced.

Also, the arrangement direction of the LED 17 and the polygon mirror 22 and the arrangement direction of the polygon mirror 22 and the light guide member 19 are substantially orthogonal to each other. In this way, the entire backlight device 12 can be kept small as compared with a case where the LEDs, the polygon mirror, and the light guide member are all linearly arranged.

Further, the polygon mirror 22 is disposed at a substantially central position of the light incident surface 19b in the scanning direction. In this way, of the light reflected by the polygon mirror 22, the light path lengths of the light reaching one end of the light incident surface 19 b and the light reaching the other end in the scanning direction are substantially equal. Become. Therefore, for example, it is possible to obtain an effect that it is easy to set the scanning period of each region of the light incident surface 19 b by the reflected light from the polygon mirror 22.

The LED 17 is disposed on the end side of the light incident surface 19b in the scanning direction. In this way, compared to the case where the LED is arranged on the center side of the light incident surface 19b in the scanning direction, it is possible to obtain an effect such as easy connection of the wiring to the LED 17, for example.

Further, the plurality of regions on the light incident surface 19b are divided so that the dimensions in the scanning direction are substantially the same. In this way, the scanning period of the reflected light from the polygon mirror 22 for each region can be made substantially the same, so that the control by the control unit 25 becomes easier.

Further, the rotating reflector is constituted by a polygon mirror 22 that rotates in one direction. In this way, each region on the light incident surface 19b can be scanned by the reflected light from the polygon mirror 22 rotating in one direction, which is particularly suitable for scanning the light incident surface 19b at a high speed.

The polygon mirror 22 has a regular polygonal shape when viewed from the direction along the rotation axis 22a. In this way, the surfaces (reflecting surfaces 22b) that reflect the light from the LED 17 are all uniform in size. Therefore, for example, if the rotation speed of the polygon mirror 22 is constant, the light incident surface 19b per unit time. The scanning range for can be made constant.

Further, the polygonal mirror 22 has a square shape when viewed from the direction along the rotation axis 22a. If it does in this way, it will become possible to make the angle range which can reflect the light from LED17 into about 180 degrees. Therefore, it is suitable particularly when the light incident surface 19b of the light guide member 19 is large in the scanning direction, and the degree of freedom of arrangement in the polygon mirror 22 in the backlight device 12 is increased.

Further, a condensing lens (condensing member) 21 is provided between the LED 17 and the polygon mirror 22 and condenses the light from the LED 17 and emits the light toward the polygon mirror 22. In this way, the light emitted from the LED 17 can be efficiently supplied to the polygon mirror 22. As a result, the light from the LED 17 can be incident on the light incident surface 19b of the light guide member 19 without waste, and the utilization efficiency can be improved. Therefore, the luminance can be improved and the power consumption can be reduced. it can.

Further, the LED 17, the condenser lens 21 and the polygon mirror 22 are arranged in a straight line, the arrangement direction of the LED 17, the condenser lens 21 and the polygon mirror 22, and the arrangement direction of the polygon mirror 22 and the light guide member 19. Are substantially orthogonal to each other. In this way, the entire backlight device 12 can be kept small as compared with the case where the LED, the condensing lens, the polygon mirror, and the light guide member are all linearly arranged.

Further, the condensing lens 21 condenses the light from the LED 17 so that the traveling direction of the light emitted toward the polygon mirror 22 is parallel to the light incident surface 19b. In this way, the light parallel to the light incident surface 19b is reflected by the polygon mirror 22 and angled, so that it can be appropriately incident on each region on the light incident surface 19b.

In addition, the condenser lens 21 is disposed at a position near the LED 17 relative to the polygon mirror 22. In this way, the light emitted from the LED 17 can be collected more efficiently.

Further, the control unit 25 periodically blinks the LED 17 to change the time ratio between the lighting period and the extinguishing period. Thus, since the light emission state of the LED 17 is controlled by a so-called PWM (Pulse Width Modulation) method, the voltage value applied to the LED 17 can be made constant, and a circuit configuration related to the control can be obtained. It can be made simple, and the dimming range can be secured sufficiently large, and the light emission state of the LED 17 can be controlled more appropriately.

The light guide member 19 is composed of a plurality of divided light guide members 19S divided into a plurality of regions on the light incident surface 19b. If it does in this way, the light which injected into each area | region in the light-incidence surface 19b can be radiate | emitted after light-guided separately by each division | segmentation light guide member 19S.

Further, an air layer (low refractive index layer) AS having a refractive index relatively lower than that of the divided light guide member 19S is interposed between the adjacent divided light guide members 19S. This makes it difficult for the light in the divided light guide member 19S to be emitted toward the air layer AS, so that light can be prevented from passing between the adjacent divided light guide members 19S, and the adjacent divided light guides can be prevented. The optical independence of the member 19S can be ensured. In addition, it is possible to secure a sufficient amount of light emitted from each divided light guide member 19S and improve luminance.

Also, the low refractive index layer is an air layer AS. This eliminates the need for a special member for forming the low refractive index layer, and thus can cope with low cost.

Further, the light source is the LED 17. In this way, high brightness and low power consumption can be achieved.

<Embodiment 2>
A second embodiment of the present invention will be described with reference to FIG. In the second embodiment, a pair of light source units 1U is provided. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

As shown in FIG. 13, a pair of light source units 1U are arranged at both ends of the long side of the chassis 114. Specifically, a predetermined interval is provided between the long-side side plates 114b and the light guide member 119 in the chassis 114, and the light source units 1U are arranged in the spaces. In other words, the light guide member 119 according to the present embodiment is disposed in a form sandwiched between the pair of light source units 1U, and both side surfaces along the entire long side direction (X-axis direction) are each light source unit 1U. And a pair of light incident surfaces 119b facing each other. Accordingly, each divided light guide member 119S has a pair of divided light incident surfaces 119bS on both side surfaces along the short side direction (X-axis direction), and is scanned by the light from each light source unit 1U facing each other. It has become so. The LED 117, LED board 118, condenser lens 121, polygon mirror 122, and synchronization detection unit 123 that constitute each light source unit 1 </ b> U are arranged symmetrically with respect to the center position of the light guide member 119. In the following, the lower light source unit 1U shown in FIG. 13 is referred to as a “first light source unit”, and a subscript A is added to the reference, whereas the upper light source unit 1U shown in FIG. B shall be attached. Specifically, the LED board 118 and the synchronization detection unit 123 that form the first light source unit 1UA are attached to the left side plate 114c shown in FIG. 13, whereas the LED board 118 and the synchronization detection that form the second light source unit 1UB. The part 123 is attached to the side plate 114c on the right side of the figure. The condensing lenses 121 forming the light source units 1UA and 1UB are arranged at positions closer to the LED 117 than the polygon mirror 122, respectively. The polygon mirrors 122 forming the light source units 1UA and 1UB are both rotated in the clockwise direction (arrow line direction) shown in FIG.

The pair of light source units 1U arranged as described above can be controlled in a plurality of ways as follows by the control unit 25 (see FIG. 6). For example, the divided light guide members 119SA to 119SH constituting the light guide member 119 can be scanned by being shared by the first light source unit 1UA and the second light source unit 1UB. Specifically, for example, for each divided light incident surface 119bS in each of the divided light guide members 119SA, 119SB, 119SC, and 119SD in the left half shown in FIG. 13 among the divided light guide members 119S, the first light source unit 1UA is used. While the scanning is performed by the reflected light from the polygon mirror 122, the divided light incident surfaces 119bS in the divided light guide members 119SE, 119SF, 119SG, and 119SH on the right half of the figure are polygons forming the second light source unit 1UB. It is possible to set so as to scan with the reflected light from the mirror 122. In addition to the above, for example, the divided light incident surfaces 119bS in the odd-numbered divided light guide members 119SA, 119SC, 119SE, and 119SG among the divided light guide members 119S are from the polygon mirror 122 that forms the first light source unit 1UA. The divided light incident surfaces 119bS of the even-numbered divided light guide members 119SB, 119SD, 119SF, and 119SH are scanned by the reflected light from the polygon mirror 122 that forms the second light source unit 1UB. It is possible to set to In this way, there is a non-scanning period in which the divided light incident surface 119bS is not scanned during the scanning period in which the reflected light from each light source unit 1U scans the divided light incident surface 119bS. Since a slight period (non-scanning period) in which the air layer AS between the adjacent divided light guide members 119S can be scanned can be continued, the light emission state of each LED 117 can be controlled more easily.

Furthermore, for example, it is of course possible to perform time-division control of the lighting states of the LEDs 117 constituting the pair of light source units 1U at the same timing by the control unit 25, and in this way, a pair of upper and lower light guide members 119 Since the light is incident on the light incident surface 119b at the same timing, it is possible to obtain an effect that unevenness in the in-plane luminance distribution of the light emitted from the light guide member 119 is less likely to occur.

<Embodiment 3>
Embodiment 3 of the present invention will be described with reference to FIG. In this Embodiment 3, what changed the arrangement | positioning of the light source unit 2U and the division | segmentation aspect of the light guide member 219 from above-mentioned Embodiment 1 is shown. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

The light source unit 2U is disposed at one end of the chassis 214 on the short side as shown in FIG. Specifically, the light source unit 2U is disposed between the light guide member 219 and the side plate 214c on the right short side shown in FIG. The LED board 218 and the synchronization detection unit 223 forming the light source unit 2U are attached to the lower long side plate 214b shown in FIG. The condenser lens 221 is disposed at a position closer to the LED 217 than the polygon mirror 222. The polygon mirror 222 is disposed at a substantially central position in the entire short side direction of the light guide member 219 (Y-axis direction, scanning direction by reflected light described later). The polygon mirror 222 is assumed to rotate in the clockwise direction (arrow line direction) shown in FIG.

Of the light guide member 219, of the both side surfaces along the entire short side direction (Y-axis direction), the surface facing the light source unit 2U is a light incident surface 219b. The light incident surface 219b is linearly scanned from the lower side to the upper side shown in FIG. 14 along the Y-axis direction by the reflected light from the polygon mirror 222 forming the light source unit 2U. The light guide member 219 is divided into six parts along the long side direction (X-axis direction) in the short side direction (Y-axis direction, the scanning direction by reflected light from the polygon mirror 222). It is divided into optical members 219S, and the divided widths are substantially equal. Light from the LED 217 whose light emission state is controlled in a time-sharing manner is incident on each split light incident surface 219bS of each split light guide member 219S via the polygon mirror 222.

<Embodiment 4>
A fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, a pair of light source units 3U described in the third embodiment is provided. In addition, the overlapping description about the same structure, effect | action, and effect as above-mentioned Embodiment 3 is abbreviate | omitted.

As shown in FIG. 15, a pair of light source units 3 </ b> U are arranged at both ends on the short side of the chassis 314. Specifically, a predetermined interval is provided between the short-side side plates 314c and the light guide member 319 in the chassis 314, and the light source units 3U are disposed in the spaces. In other words, the light guide member 319 according to the present embodiment is arranged in a form sandwiched between the pair of light source units 3U, and both side surfaces along the entire short side direction (Y-axis direction) are respectively light source units 3U. And a pair of light incident surfaces 319b facing each other. Therefore, each divided light guide member 319S has a pair of divided light incident surfaces 319bS on both side surfaces along the short side direction (X-axis direction), and is scanned by the light from each light source unit 3U facing each other. It has become so. The LED 317, the LED substrate 318, the condenser lens 321, the polygon mirror 322, and the synchronization detection unit 323 constituting each light source unit 3U are arranged in point symmetry with the center position of the light guide member 319 as a symmetric point. Hereinafter, the light source unit 3U on the right side shown in FIG. 15 is referred to as a “first light source unit”, and a suffix A is attached to the reference numeral, whereas the light source unit 3U on the left side in FIG. Shall be attached. Specifically, the LED substrate 318 and the synchronization detection unit 323 that form the first light source unit 3UA are attached to the lower side plate 314b shown in FIG. 15, whereas the LED substrate 318 that forms the second light source unit 3UB and the synchronization. The detector 323 is attached to the upper side plate 314b in the figure. The condensing lenses 321 forming the light source units 3UA and 3UB are arranged at positions closer to the LED 317 than the polygon mirror 322, respectively. Both the polygon mirrors 322 forming the light source units 3UA and 3UB rotate in the clockwise direction (arrow line direction) shown in FIG.
The pair of light source units 3U arranged as described above can be controlled in a plurality of ways by the control unit 25 (see FIG. 6), details of which are described in the second embodiment. Since it is the same as what was described, the overlapping description is omitted.

<Embodiment 5>
A fifth embodiment of the present invention will be described with reference to FIG. In the fifth embodiment, a galvanometer mirror 27 is used in place of the polygon mirror 22 described in the first embodiment. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

As shown in FIG. 16, the galvanometer mirror 27 has a horizontally long plate shape and a surface facing the light guide member 19 side as a reflection surface 27b, and is rotatable about a rotation shaft 27a. . Specifically, the galvanometer mirror 27 is reciprocally swung around the rotation shaft 27a in the direction of the arrow shown in FIG. 16, and accordingly, the light from the condenser lens 21 toward the galvanometer mirror 27 is detected. The angle of the reflection surface 27b is changed in a time division manner, and the traveling direction of the light reflected by the reflection surface 27b is changed in a time division manner. Then, the reflected light from the galvano mirror 27 moves along the long side direction (X) of the light incident surface 19b (divided light incident surface 19bS) of the light guide member 19 (divided light guide member 19S) as the galvano mirror 27 rotates. It is possible to scan linearly from the left side to the right side shown in FIG.
In addition, as another example of the rotating reflector that reciprocally swings, a resonant mirror can be cited, which can be used in place of the galvanometer mirror 27 described above.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above-described embodiments, the light guide member is divided into a plurality of parts. However, the present invention includes a structure in which the light guide member is not divided. Specifically, as shown in FIG. 17, the number of the light guide member 19 'can be one, and even in that case, each region separated by the one-dot chain line in the light incident surface 19b'. The light emission state of the LED 17 may be controlled in a time-sharing manner for each scanning period of the reflected light from the polygon mirror 22.

(2) In the first to fourth embodiments described above, the polygon mirror is shown to be square when viewed from the direction along the rotation axis. For example, as shown in FIG. 18, along the rotation axis 22a ′. It is also possible to use a polygon mirror 22 ′ that is a regular hexagon when viewed from the direction.

(3) In addition to the above (2), the shape of the polygon mirror viewed from the direction along the rotation axis may be other regular polygons such as a regular triangle, a regular pentagon, a regular heptagon, and a regular octagon. It is.

(4) In addition to the above (3), the shape of the polygon mirror viewed from the direction along the rotation axis may be a non-regular polygon such as an isosceles triangle or a trapezoid.

(5) In each embodiment described above, a polygon mirror, a galvano mirror, and a resonant mirror are exemplified as the rotating reflector. However, other rotating reflectors using MEMS (Micro Electro Mechanical System) technology are used. Is also possible.

(6) In each of the above embodiments, the control unit performs PWM control of the light emission state of the LED, but it is of course possible to control the light emission state of the LED by other methods. For example, the light emission state of the LED can be controlled in a time-sharing manner by changing the drive voltage for driving the LED in a time-sharing manner.

(7) In each of the above-described embodiments, the case where the light emission state of the LED is synchronized with the rotation state (rotation state) of the polygon mirror (galvano mirror) by the synchronization detection unit has been described. It can be omitted. In that case, for example, a sensor is provided in an electromagnetic motor for rotationally driving the polygon mirror so that the rotation state is directly detected, and the light emission state of the LED is controlled by the control unit based on the detection signal. .

(8) In each of the above-described embodiments, the division width in the light guide member, that is, the case where the dimensions in the scanning direction in each division light guide member are substantially equalized, but the division width in the light guide member is set to be different. It is also possible.

(9) In the first embodiment described above, among the side plates on the short side of the chassis, the left side plate shown in FIG. 3 is attached with the LED substrate and the synchronization detection unit, but the opposite side (FIG. 3 Of course, it does not matter if the LED substrate and the synchronization detection unit are attached to the side plate on the right side.

(10) In the above-described third embodiment, among the long side plates of the chassis, the lower side plate shown in FIG. 14 is attached with the LED substrate and the synchronization detection unit. Needless to say, the LED board and the synchronization detection unit may be attached to the upper side plate shown in FIG.

(11) In the above-described embodiments, the LED board is attached to the side plate of the chassis. For example, a heat sink having an L-shaped cross section is prepared, the LED board is attached to the heat sink, and the heat sink is attached to the chassis. It may be attached to the bottom plate.

(12) In each of the above-described embodiments, one or two light source units are arranged in the chassis, but three or four light source units are arranged in the chassis. included.

(13) In each of the above-described embodiments, an arrangement in which the arrangement direction of the LED, the condenser lens and the polygon mirror (galvano mirror) and the arrangement direction of the polygon mirror (galvano mirror) and the light guide member are orthogonal to each other. Although illustrated, it is also possible to set the above-described two alignment directions to make an angle of 90 degrees or more (obtuse angle) or to make an angle of 90 degrees or less (acute angle). Even in that case, it is preferable that the traveling direction of the light condensed by the condenser lens is set to coincide with the arrangement direction of the LED and the polygon mirror (galvano mirror).

(14) In each of the above-described embodiments, the polygon mirror (galvano mirror) is arranged at the substantially central position in the scanning direction on the light incident surface. However, the polygon mirror (galvano mirror) is displaced from the central position. What was made into the arrangement | positioning was also included in this invention.

(15) In each of the above-described embodiments, the LED is arranged at the position that is the end in the scanning direction on the light incident surface. Those arranged close to each other are also included in the present invention.

(16) In each of the above-described embodiments, the synchronization detection unit is attached to the same side plate as the LED substrate and arranged at a position between the LED and the light guide member. Can be attached to a side plate (for example, the opposite side plate) different from the LED substrate. Furthermore, it is also possible to place the synchronization detection unit on the same side plate as the LED substrate, and arrange the LED between the light guide member and the LED.

(17) In the above-described embodiments, the air layer is used as the low refractive index layer interposed between the adjacent divided light guide members. However, a low refractive index layer made of a low refractive index material may be used. Is possible.

(18) In each of the embodiments described above, the air layer is interposed between the adjacent divided light guide members, but a reflective layer made of a reflective sheet or the like having excellent light reflectivity is used instead of the air layer. It is also possible.

(19) In each of the above-described embodiments, the case where the condensing lens is used as the condensing member is shown, but a condensing member other than the lens can also be used.

(20) In each of the above-described embodiments, the LED is used as the light source. However, other types of light sources (cold cathode tube, hot cathode tube, laser light source, etc.) can of course be used.

(21) In each of the above-described embodiments, a specific example of the display period of one display image on the liquid crystal panel is shown as 1/60 seconds or 1/120 seconds. It is also possible to change to 240 seconds or the like, and the scanning period for the light incident surface by the reflected light of the rotating reflector may be changed accordingly. In addition, the specific numerical value of the above-described display period can be appropriately changed in addition to the above.

(22) In Embodiment 2 and Embodiment 4 described above, the LED substrate and synchronization detection unit forming the first light source unit and the LED substrate and synchronization detection unit forming the second light source unit are attached to different side plates of the chassis. In this case, the LED substrate and the synchronization detection unit forming the first light source unit and the LED substrate and the synchronization detection unit forming the second light source unit are attached to the same side plate. It is also possible to arrange them (arranged on the same side). In that case, the polygon mirror forming the first light source unit and the polygon mirror forming the second light source unit may be set so that the rotation directions are opposite.

(23) In each of the above-described embodiments, the liquid crystal panel is illustrated in a vertically placed state in which the short side direction coincides with the vertical direction, but the liquid crystal panel matches the long side direction with the vertical direction. What is set in a vertical state is also included in the present invention.

(24) In the above-described embodiment, the TFT is used as the switching element of the liquid crystal display device. However, the present invention can also be applied to a liquid crystal display device using a switching element other than TFT (for example, a thin film diode (TFD)), and color display. In addition to the liquid crystal display device, the present invention can be applied to a liquid crystal display device that displays black and white.

(25) In each of the above-described embodiments, the liquid crystal display device using the liquid crystal panel as the display panel has been exemplified. However, the present invention can also be applied to a display device using another type of display panel.

(26) In each of the above-described embodiments, the television receiver provided with the tuner is exemplified. However, the present invention can be applied to a display device not provided with the tuner.

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device (display device), 11 ... Liquid crystal panel (display panel), 12 ... Backlight device (illumination device), 17, 117, 217, 317 ... LED (light source), 19, 119, 219, 319 ... Light guide member, 19S, 119S, 219S, 319S ... split light guide member, 19b, 119b, 219b, 319b ... light incident surface, 19bS, 119bS, 219bS, 319bS ... split light entrance surface (region), 21, 121, 221 , 321 ... Condensing lens (condensing member) 22, 122, 222, 322 ... Polygon mirror (rotating reflector), 22a ... Rotating shaft, 22b ... Reflecting surface (surface), 25 ... Control unit, 27 ... Galvano Mirror (rotating reflector), AS ... Air layer (low refractive index layer), TV ... TV receiver

Claims

A light source;
A light guide member having a light incident surface on which light from the light source is incident;
A rotating reflector that reflects the light from the light source while being rotated and scans the light incident surface with the reflected light; and
When the light incident surface is divided into a plurality of regions in the scanning direction by the reflected light from the rotating reflector, the light emission state of the light source is time-divided in association with the reflected light scanning period for each region. An illuminating device provided with the control part to control.
The lighting device according to claim 1, wherein the alignment direction of the light source and the rotating reflector and the alignment direction of the rotating reflector and the light guide member are substantially orthogonal to each other.
The lighting device according to claim 1 or 2, wherein the rotating reflector is disposed at a substantially central position of the light incident surface in the scanning direction.
The illuminating device according to any one of claims 1 to 3, wherein the light source is disposed on an end side of the light incident surface in the scanning direction.
The illumination device according to any one of claims 1 to 4, wherein the plurality of regions on the light incident surface are partitioned so that dimensions in the scanning direction are substantially the same.
The illumination device according to any one of claims 1 to 5, wherein the rotating reflector is configured by a polygon mirror that rotates in one direction.
The lighting device according to claim 6, wherein the polygon mirror has a regular polygonal shape when viewed from a direction along the rotation axis.
The lighting device according to claim 7, wherein the polygonal mirror has a square shape when viewed from a direction along a rotation axis thereof.
9. The light emitting device according to claim 1, further comprising a light collecting member that is interposed between the light source and the rotating reflector and collects light from the light source and emits the light toward the rotating reflector. The lighting device according to item 1.
The light source, the light condensing member, and the rotating reflector are arranged in a straight line, the alignment direction of the light source, the condensing member, and the rotating reflector, the rotating reflector, and the rotating reflector The lighting device according to claim 9, wherein the alignment direction of the light guide members is substantially orthogonal to each other.
The said condensing member condenses the light from the said light source so that the advancing direction of the light radiate | emitted toward the said rotation reflector may be parallel to the said light-incidence surface. 10. The lighting device according to 10.
The lighting device according to any one of claims 9 to 11, wherein the light condensing member is disposed in a position near the light source relative to the rotating reflector.
The lighting device according to any one of claims 1 to 12, wherein the control unit periodically blinks the light source to change a time ratio between a lighting period and a light-off period.
The lighting device according to any one of claims 1 to 13, wherein the light guide member includes a plurality of divided light guide members divided for each of the plurality of regions on the light incident surface.
The lighting device according to claim 14, wherein a low refractive index layer having a refractive index relatively lower than that of the divided light guide member is interposed between the adjacent divided light guide members.
The lighting device according to claim 15, wherein the low refractive index layer is an air layer.
The lighting device according to any one of claims 1 to 16, wherein the light source is an LED.
A display device comprising: the lighting device according to any one of claims 1 to 17; and a display panel that performs display using light from the lighting device.
The display device according to claim 18, wherein the display panel is a liquid crystal panel in which liquid crystal is sealed between a pair of substrates.
A television receiver comprising the display device according to claim 18 or 19.