JP6474630B2 - Display device - Google Patents

Description

  The present invention relates to a display device.

  The edge-light type light source device mounted on the display device uses white light guided to the light guide plate to partially emit light from the light guide plate in order to display a high contrast image and reduce power consumption. The partial drive which emits can be performed. A light source device mounted on such a display device has been proposed with a technique for improving moving image blur of the display device without increasing power consumption.

JP 2014-102295 A

  The present invention provides a display device that reduces deterioration in image quality.

One embodiment of the present invention is an image display panel, a light source that emits light, and a rear surface of the image display panel that is incident on the side surface of the surface facing the image display panel and transmits the light. A light source device including a plurality of regions divided in a direction intersecting a traveling direction of the light, including a light modulation layer that can be controlled to a transmission state or a scattering state that scatters the light, The light corresponding to each region is controlled by controlling the light modulation layer corresponding to each region to the scattering state during the scattering control time of the light modulation layer corresponding to each region set so as not to overlap in time. The scattering state of the modulation layer is controlled so as to temporally overlap a part of the scattering control time corresponding to the region that is farther from the side surface than the region, and the light modulation layer is Control to scattering state A control device for controlling the light source device in the driving pattern in accordance with the distance from the side surface of the region including the light modulation layer, was closed at the time, the control device, to the image display panel from the area The brightness of the light modulation layer corresponding to the area when the brightness of the emitted light emitted from the area around the area is higher than the brightness of the emitted light emitted to the image display panel. In the display device, the state is controlled so as to temporally overlap a part of the scattering control time of the light modulation layer corresponding to the region farther from the side surface than the region .

It is a figure which shows the structural example of the display apparatus of 1st Embodiment. It is a figure which shows the hardware structural example of the display apparatus of 2nd Embodiment. It is a top view which shows the structural example of the planar light source device of 2nd Embodiment. It is sectional drawing which shows the structural example of the planar light source device of 2nd Embodiment. It is a top view which shows the structural example of the upper electrode of the light guide of 2nd Embodiment. It is a top view which shows the structural example of the lower electrode of the light guide of 2nd Embodiment. It is a schematic diagram explaining the effect | action of the light modulation layer of 2nd Embodiment. It is a figure which shows an example of the partial drive of the planar light source device of 2nd Embodiment. It is a figure which shows the function structural example contained in the display apparatus of 2nd Embodiment. It is a figure which shows the function structural example of the signal processing part contained in the display apparatus of 2nd Embodiment. It is a figure which shows the drive pattern which changed the light emission output of the sidelight light source of 2nd Embodiment. It is a figure which shows the drive pattern which changed the intensity of the electric field of 2nd Embodiment. It is a figure which shows the drive pattern which changed the length of time to generate the electric field of 2nd Embodiment. It is a figure which shows the timing of the outgoing scanning and video scanning of 2nd Embodiment. It is a figure which shows the drive pattern in the case of enlarging the brightness difference of the light radiate | emitted from the one part area | region of the output surface of 3rd Embodiment, and the light radiate | emitted from another area | region. It is a modification of the aspect of the voltage difference between the electrodes in the overlap part of 3rd Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate modifications while maintaining the spirit of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part as compared with the embodiments for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited thereto. It is not limited.

In addition, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate.
[First Embodiment]
The display device of the first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration example of a display device according to the first embodiment.

The display device 1 includes an image display panel 10, a light source device 20, and a control device 30.
The image display panel 10 displays a predetermined image. The light source device 20 emits light to the image display panel 10. The light source device 20 includes a light source 21 and a light guide 22. The light source 21 emits light.

  The light guide 22 is disposed on the back surface of the image display panel 10, enters light emitted from the light source 21 from the side surface 23 of the surface facing the image display panel 10, and emits light to the image display panel 10. The light guide 22 has a plurality of regions (regions 22a, 22b, 22c, 22d, 22e, and 22f) that are divided in a direction that intersects the light traveling direction. Each region includes a light modulation layer that can be controlled to be a transmission state that transmits light or a scattering state that scatters light.

  The light modulation layer is, for example, a polymer-dispersed liquid crystal layer, and is controlled to a transmission state or a scattering state by generating an electric field. Therefore, when the light modulation layer corresponding to the region is in a transmissive state, the light passes through the region and travels to the adjacent region (light traveling direction). On the other hand, when the light modulation layer corresponding to the region is in a scattering state, the light is scattered by the light modulation layer, and a part of the scattered light is emitted from the region to the image display panel 10.

  The control device 30 controls the light source device 20. The control device 30 controls the light modulation layer corresponding to each region to be in a scattering state by generating an electric field in the light modulation layer corresponding to each region during the scattering control time of the light modulation layer corresponding to each region. The scattering control time of the light modulation layer corresponding to each region is set so as not to overlap in time. That is, the control device 30 controls the light modulation layer corresponding to each region in a scattering state (so that there is only one region including the light modulation layer in the scattering state) so as not to overlap in time.

  In this way, the light source device 20 controls the light modulation layer to the scattering state by the control device 30 controlling the light modulation layer corresponding to each region to the scattering state during the scattering control time of the light modulation layer corresponding to each region. Driving is performed by partial driving in which light is emitted to the image display panel 10 in order from the formed area.

  Here, a specific example in which the light source device 20 is partially driven by the control device 30 controlling the light modulation layer corresponding to each region in the scattering state during the scattering control time will be described. For example, when the control device 30 generates an electric field with respect to the light modulation layer corresponding to the region 22b and controls the light modulation layer to be in a scattering state, the light emitted from the light source 21 enters the light guide 22 from the side surface 23 and is modulated. The layer passes through a region 22a that is controlled to be transmissive. The light emitted from the light source 21 is scattered by the light modulation layer corresponding to the region 22b controlled to be in a scattering state, and light traveling toward the image display panel 10 from the scattered light is transferred from the region 22b to the image display panel 10. Are emitted.

  On the other hand, when the control device 30 generates an electric field for the light modulation layer corresponding to the region 22e and controls the light modulation layer to be in a scattering state, the light emitted from the light source 21 enters the light guide 22 from the side surface 23 and is modulated. The layers pass through the regions 22a, 22b, 22c, 22d that are controlled to be transmissive. The light emitted from the light source 21 is scattered by the light modulation layer corresponding to the region 22e controlled to be in a scattering state, and light traveling toward the image display panel 10 among the scattered light is transferred from the region 22e to the image display panel 10. Are emitted.

  As described above, the light emitted from the light source 21 increases the distance from the side surface 23 of the region that emits light to the image display panel 10 as the light passes through the region until the light is emitted from the light guide 22. The number increases. By the way, it is known that the intensity of light may change (attenuate) when passing through the region. The intensity of light is, for example, light brightness, brightness, and the like.

  Therefore, if the control device 30 partially drives the light source device 20 under the same driving conditions in the entire region, the intensity of light emitted from the light guide 22 may be shifted for each region. Therefore, it is desired that the control device 30 changes the control mode for each region.

  Therefore, when the control device 30 controls the light modulation layer corresponding to each region to the scattering state during the scattering control time of the light modulation layer corresponding to each region, the distance from the side surface 23 of the region including the light modulation layer is controlled. The light source device 20 is controlled with a drive pattern according to the above. The control device 30 controls the intensity of light emitted from the light source 21, the length of time that the light modulation layer is in the scattering state, and the degree of scattering in the scattering state of the light modulation layer as the drive pattern of the light source device 20.

  For example, the control device 30 sets the intensity of light emitted from the light source 21 and the length of time during which the light modulation layer is in the scattering state to the same condition in the entire region, and the side surface of the region including the light modulation layer that is controlled to the scattering state. According to the distance from 23, the intensity of the electric field at the time of controlling to a scattering state is changed.

  Specifically, when the control device 30 emits light of a predetermined intensity from each region, the farther the region including the light modulation layer that is controlled to the scattering state is from the side surface 23, the more the light modulation layer is in the scattering state. The electric field strength is controlled so that the degree of scattering is high. As described above, the farther the region is from the side surface 23, the higher the degree of scattering in the scattering state of the light modulation layer. The farther the region is from the side surface 23, the more light is scattered in the light modulation layer. It becomes possible to emit a lot of the light that has reached.

  Alternatively, the control device 30 sets the scattering degree in the scattering state of the light modulation layer and the length of time in which the light modulation layer is in the same state in the entire region, and from the side surface 23 of the region including the light modulation layer controlled to the scattering state. The intensity of light emitted from the light source 21 is changed according to the distance.

  Specifically, when the control device 30 emits light of a predetermined intensity from each region, the farther the region including the light modulation layer controlled to be in a scattering state is farther from the side surface 23, the light emitted from the light source 21. Control to increase the strength.

  Alternatively, the control device 30 sets the scattering degree in the scattering state of the light modulation layer and the intensity of the light emitted from the light source 21 in the same condition in the entire region, and from the side surface 23 of the region including the light modulation layer controlled to the scattering state. The length of time for generating the electric field to be controlled in the scattering state is changed according to the distance. Specifically, when the control device 30 emits light of a predetermined intensity from each region, the light modulation layer becomes more scattered as the region including the light modulation layer controlled to the scattering state becomes farther from the side surface 23. The length of time for generating the electric field is controlled so that the time to become longer.

  Thus, when controlling the light modulation layer in the scattering state, the control device 30 controls the light source device 20 with the drive pattern according to the distance from the side surface 23 of the region including the light modulation layer. The attenuation of light intensity can be corrected.

  Thereby, the control apparatus 30 can suppress that the intensity | strength of the light radiate | emitted from each area | region deviates from desired intensity | strength, when driving the light source device 20 partially. As a result, the display device 1 can reduce deterioration in image quality.

[Second Embodiment]
In the second embodiment, the display device of the first embodiment will be described more specifically.
First, a hardware configuration example of the display device according to the second embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating a hardware configuration example of the display device according to the second embodiment.

The display device 100 is an embodiment of the display device 1 shown in FIG. 1, and the entire device is controlled by a control unit 100a.
In the control unit 100a, a CPU (Central Processing Unit) 100a1, a RAM (Random Access Memory) 100a2, a ROM (Read Only Memory) 100a3, and a plurality of peripheral devices can mutually input and output signals via the bus 100f. It is connected to the.

  The CPU 100a1 controls the entire display device 100 based on an OS (Operating System) program or application program stored in the ROM 100a3 and various data expanded in the RAM 100a2. At the time of execution of the process, it may be operated by an OS program or an application program temporarily stored in the RAM 100a2.

  The RAM 100a2 is used as a main storage device of the control unit 100a. The RAM 100a2 temporarily stores at least part of OS programs and application programs to be executed by the CPU 100a1. The RAM 100a2 stores various data necessary for processing by the CPU 100a1.

  The ROM 100a3 is a read-only semiconductor storage device that stores an OS program, an application program, and fixed data that is not rewritten. Further, instead of the ROM 100a3 or in addition to the ROM 100a3, a semiconductor storage device such as a flash memory can be used as a secondary storage device.

  Peripheral devices connected to the bus 100f include a display driver IC (Integrated Circuit) 100b, an LED (Light Emitting Diode) driver IC 100c, an input / output interface 100d, and a communication interface 100e.

  An image display panel 200 is connected to the display driver IC 100b. The display driver IC 100 b displays an image on the image display panel 200 by outputting an output signal to the image display panel 200. The display driver IC 100b can also realize at least a part of functions of an image display panel driving unit described later.

  The planar light source device 300 (one embodiment of the light source device 20 of the first embodiment) is connected to the LED driver IC 100c. The LED driver IC 100c drives the light source in accordance with a light source control signal described later, and controls the luminance of the planar light source device 300. The LED driver IC 100c realizes at least a part of functions of a planar light source device driving unit (one embodiment of the control device 30 of the first embodiment) described later.

  An input device for inputting user instructions is connected to the input / output interface 100d. For example, an input device such as a keyboard, a mouse used as a pointing device, or a touch panel is connected. The input / output interface 100d transmits a signal sent from the input device to the CPU 100a1.

The communication interface 100e is connected to the network 1000. The communication interface 100e transmits / receives data to / from other computers or communication devices via the network 1000.
With the hardware configuration as described above, the processing functions of this embodiment can be realized.

  Next, a configuration example of the planar light source device 300 will be described with reference to FIGS. FIG. 3 is a plan view illustrating a configuration example of the planar light source device according to the second embodiment, and FIG. 4 is a cross-sectional view illustrating a configuration example of the planar light source device according to the second embodiment. FIG. 5 is a plan view illustrating a configuration example of the upper electrode of the light guide according to the second embodiment. FIG. 6 is a plan view illustrating a configuration example of the lower electrode of the light guide according to the second embodiment.

  The planar light source device 300 is disposed on the back side of the image display panel 200 and emits light on the back side of the image display panel 200. The planar light source device 300 includes a light guide 310 and a sidelight light source 302 in which at least one side surface of the light guide 310 is an entrance surface E and light sources 303a to 303j are arranged at positions facing the entrance surface E. I have.

  The light sources 303a to 303j of the sidelight light source 302 are light emitting diodes (LEDs) for incident light (for example, white light), and are configured such that the current or PWM value (duty ratio, etc.) can be controlled independently. . The light sources 303a to 303j (FIG. 3) are arranged along one side surface of the light guide 310. When the direction in which the light sources 303a to 303j are arranged is the light source arrangement direction LY, the incident direction LX orthogonal to the light source arrangement direction LY. The incident light from the light sources 303a to 303j enters the light guide 310 from the incident surface E. The light sources 303a to 303j are not limited to light emitting diodes, and semiconductor lasers can also be used.

  The light guide 310 guides light from the sidelight light source 302 (light sources 303 a to 303 j) arranged on the side surface thereof to the upper surface of the light guide 310. The light guide 310 has a shape corresponding to the image display panel 200 disposed on the upper surface side of the planar light source device 300. The light guide 310 includes a plurality of regions divided in a direction intersecting the light traveling direction. It should be noted that numbers are assigned to the regions (1) to (6) in the order closer to the sidelight light source 302.

  The planar light source device driving unit 500 is connected to the sidelight light source 302 (light sources 303a to 303j) and the light guide 310 so that signals can be transmitted. The planar light source device driving unit 500 is a partial light source device that partially emits light sequentially from the emission surfaces (surfaces facing the image display panel 200) of the regions (1) to (6) of the light guide 310. 300 is driven. The partial drive will be described later in detail with reference to FIG.

  Here, the planar light source device 300 will be described more specifically with reference to FIG. The planar light source device 300 includes a sidelight light source 302, a light guide 310, and a reflection sheet 330 provided on the lower surface of the light guide 310 (the surface opposite to the surface facing the image display panel 200). Composed.

  The reflection sheet 330 returns light leaking from the back surface of the light guide 310 (the lower surface in FIG. 4) to the light guide 310 side, and has functions such as reflection, diffusion, and scattering. . Thereby, the incident light from the sidelight light source 302 can be used efficiently, and it contributes to the improvement of the brightness | luminance of the output surface of the planar light source device 300. FIG. As the reflection sheet 330, for example, foamed PET (polyethylene terephthalate), a silver vapor deposition film, a multilayer film reflection film, white PET, or the like can be used. In FIG. 4, the reflection sheet 330 is laminated through an air layer, and is not optically adhered.

The light guide 310 includes a transparent substrate 311, an upper electrode 312, an alignment film 313, a light modulation layer 314 and a spacer 315, an alignment film 316, a lower electrode 317, and a transparent substrate 318 arranged in this order. is there.
The transparent substrates 311 and 318 support the light modulation layer 314 and are generally made of a substrate transparent to visible light, such as a glass plate or a plastic film.

  The upper electrode 312 is a transparent electrode provided on the transparent substrate 311 so as to face the transparent substrate 318. Here, the upper electrode 312 will be described with reference to FIG. For example, as shown in FIG. 5, the upper electrode 312 is provided in a strip shape extending in a direction parallel to the extending direction of the sidelight light source 302 corresponding to each in-plane region.

  The upper electrode 312 is connected to a different wiring 312a for each upper electrode 312 corresponding to the regions (1) to (6). The upper electrode 312 is electrically connected by the connected wiring 312a. In the upper electrode 312, a voltage corresponding to a signal from the planar light source device driving unit 500 is applied to the connection terminal 312 b at the end of the wiring 312 a. As a result, the upper electrode 312 is controlled for each upper electrode 312 corresponding to the regions (1) to (6). Returning to FIG. 4, the description will be continued.

  The lower electrode 317 is provided on the transparent substrate 318 so as to face the transparent substrate 311. Here, the lower electrode 317 will be described with reference to FIG. As shown in FIG. 6, the lower electrode 317 has a strip shape extending in a direction parallel to the in-plane region and facing the upper electrode 312. The lower electrode 317 is electrically connected by the connected wiring 317a, and a voltage corresponding to a signal from the planar light source device driving unit 500 is applied to the connection terminal 317b at the end of the wiring 317a. In the light modulation layer corresponding to each region, an electric field corresponding to a voltage difference between the upper electrode 312 and the lower electrode 317 corresponding to each region (hereinafter, voltage difference between the electrodes) is generated. Note that the shapes of the upper electrode 312 and the lower electrode 317 are not limited to the above shapes as long as an electric field can be generated in the light modulation layer corresponding to the region independently for each region. Returning to FIG. 4, the description will be continued.

The alignment films 313 and 316, for example, align liquid crystal molecules 314b used for the light modulation layer 314. Examples of the alignment film include a vertical alignment film and a horizontal alignment film.
The spacer 315 controls the interval between the transparent substrates 311 and 318. The spacer 315 is formed of a transparent material that transmits light. The spacer 315 is formed in a region that does not overlap with the upper electrode 312 and the lower electrode 317. The spacer 315 transmits light more than the light modulation layer 314 in the transmissive state. Therefore, by providing the spacer 315, it is possible to suppress the attenuation of light traveling in the light guide 310 compared to the case where the light modulation layer 314 is provided on the entire surface. Note that the light guide 310 may not include the spacer 315.

  The light modulation layer 314 is a polymer-dispersed liquid crystal layer, and is composed of a composite layer including a liquid crystal monomer 314a and a plurality of liquid crystal molecules 314b dispersed in the liquid crystal monomer 314a. The liquid crystal monomer 314a and the liquid crystal molecule 314b have the same optical anisotropy.

  The operation of the light modulation layer 314 will be described with reference to FIG. FIG. 7 is a schematic diagram for explaining the operation of the light modulation layer of the second embodiment. The optical axes Ax1 and Ax2 described in FIGS. 7A and 7B are lines parallel to the traveling direction of the light beam so that the refractive index becomes one value regardless of the polarization direction. The liquid crystal monomers 314a and liquid crystal molecules 314b in (A) and (B) are schematically shown.

First, a case where there is no voltage difference between electrodes corresponding to a region and no electric field is generated in the light modulation layer 314 in the region will be described with reference to FIG.
In this case, the directions of the optical axis Ax1 of the liquid crystalline monomer 314a and the optical axis Ax2 of the liquid crystalline molecule 314b coincide with each other (become parallel) (FIG. 7A). Further, the directions of the optical axis Ax1 and the optical axis Ax2 do not always have to completely coincide with each other, and the direction of the optical axis Ax1 and the direction of the optical axis Ax2 may be slightly shifted due to, for example, a manufacturing error. .

When no electric field is generated in the light modulation layer, the optical axis Ax2 of the liquid crystal molecules 314b is orthogonal to the surfaces of the transparent substrates 311 and 318. On the other hand, as shown in FIGS. 7A and 7B, the liquid crystal monomer 314a has the optical axis Ax1 of the liquid crystal monomer 314a of the transparent substrates 311 and 318 regardless of the presence or absence of the electric field of the light modulation layer 314. The structure is orthogonal to the surface. The optical axis Ax2 does not always need to be completely orthogonal to the surfaces of the transparent substrates 311 and 318. For example, even if the optical axis Ax2 intersects the surfaces of the transparent substrates 311 and 318 at an angle other than 90 degrees due to manufacturing errors or the like. Good. Further, the optical axis Ax1 does not always need to be completely orthogonal to the surfaces of the transparent substrates 311 and 318. For example, even if the optical axis Ax1 intersects the surfaces of the transparent substrates 311 and 318 at an angle other than 90 degrees due to a manufacturing error or the like. Good.

  Here, it is preferable that the ordinary light refractive indexes of the liquid crystalline monomer 314a and the liquid crystalline molecule 314b are equal to each other, and the extraordinary refractive indexes of the liquid crystalline monomer 314a and the liquid crystalline molecule 314b are equal to each other. In this case, for example, when there is no voltage difference between the electrodes and no electric field is generated in the light modulation layer 314, as shown in FIG. Is obtained. As a result, for example, the light L1 traveling in the front (upper part in FIG. 7) direction and the light L2 and light L3 traveling in the oblique (upper oblique direction in FIG. 7) direction are not scattered in the light modulation layer 314 and are modulated. Permeate layer 314.

Next, regarding the light modulation layer 314, a case where an electric field is generated in the light modulation layer 314 due to a voltage difference between electrodes (corresponding to an arbitrary region of the emission surface) will be described.
In this case, since the optical axis Ax2 is inclined by the electric field generated in the light modulation layer 314 due to the voltage difference between the electrodes of the liquid crystalline molecules 314b, the optical axis Ax1 of the liquid crystalline monomer 314a and the optical axis of the liquid crystalline molecules 314b. Ax2 directions are different from each other (intersect) (FIG. 7B). The liquid crystalline molecules 314b have an optical axis Ax2 other than 90 degrees with respect to the surfaces of the transparent substrates 311 and 318, for example, when an electric field is generated in the light modulation layer 314 due to a voltage difference between the electrodes. The structure is such that they intersect at an angle or are parallel. Therefore, when an electric field is generated in the light modulation layer 314 due to the voltage difference between the electrodes, the refractive index difference is increased in all directions in the light modulation layer 314, and high scattering properties are obtained. Thereby, for example, as illustrated in FIG. 7B, the light L <b> 1 traveling in the front direction and the light L <b> 2 and the light L <b> 3 traveling in the oblique direction are scattered in the light modulation layer 314.

  The ordinary refractive index of the liquid crystalline monomer 314a and the liquid crystalline molecule 314b may be slightly deviated due to, for example, a manufacturing error, and is preferably 0.1 or less, and preferably 0.05 or less. More preferred. Further, the extraordinary refractive index of the liquid crystalline monomer 314a and the liquid crystalline molecule 314b may be slightly deviated due to, for example, a manufacturing error, and is preferably 0.1 or less, preferably 0.05 or less. Is more preferable.

Further, the refractive index difference (Δn ₀ = extraordinary light refractive index n ₀ -normal light refractive index n ₁ ) of the liquid crystalline monomer 314a and the refractive index difference of the liquid crystalline molecule 314b (Δn ₁ = abnormal light refractive index n ₂ -normal light refraction). The ratio n ₃ ) is preferably as large as possible, preferably 0.05 or more, more preferably 0.1 or more, and further preferably 0.15 or more. When the difference in refractive index between the liquid crystal monomer 314a and the liquid crystal molecule 314b is large, the light modulation layer 314 has high scattering ability, and the light guide conditions of the light guide 310 can be easily broken. It becomes easy to take out light from 310.

  The liquid crystalline monomer 314a included in the light modulation layer 314 has, for example, a streak structure or a porous structure that does not respond to an electric field, or a response speed slower than the response speed of the liquid crystal molecules 314b. It has a rod-like structure having The liquid crystalline monomer 314a is formed by, for example, aligning a material having alignment properties and polymerizability (for example, a monomer) along the alignment direction of the liquid crystal molecules 314b or the alignment directions of the alignment films 313 and 316 with at least one of heat and light. It is formed by polymerizing. On the other hand, the liquid crystalline molecules 314b are mainly composed of a liquid crystal material, for example, and have a response speed sufficiently faster than the response speed of the liquid crystalline monomer 314a.

  The monomer having orientation and polymerizability may be any material that has optical anisotropy and is composited with liquid crystal, and is particularly preferably a low molecular weight monomer that is cured by ultraviolet rays. Since the direction of optical anisotropy between the liquid crystal and the polymerized low-molecular monomer (polymer material) preferably coincides in the state where no electric field is generated, The liquid crystal and the low molecular weight monomer are preferably aligned in the same direction. When liquid crystal is used as the liquid crystalline molecule 314b, when the liquid crystal is a rod-like molecule, the shape of the monomer material used is preferably rod-like. From the above, it is preferable to use a material having both polymerizability and liquid crystallinity as the monomer material. For example, the monomer material includes an acryloyloxy group, a methacryloyloxy group, a vinyl ether group, and an epoxy group as the polymerizable functional group. It preferably has at least one functional group selected from the group. These functional groups can be polymerized by irradiation with ultraviolet rays, infrared rays or electron beams, or by heating. A liquid crystalline material having a polyfunctional group can also be added in order to suppress a decrease in the degree of alignment during ultraviolet irradiation. When the alignment films 313 and 316 are not used, a state in which these materials are aligned by an external field such as a magnetic field or an electric field is temporarily created, and an alignment state is created by curing the monomer by ultraviolet rays or heat. You can also

In addition, although the type which makes a transition from a transmission state to a scattering state by an electric field (here, “normally transparent”) is shown, the type which makes a transition from a scattering state to a transmission state by an electric field (here, “normally scattering”). ) Further, the light guide 310 only needs to have a function of allowing light emitted from the sidelight light source 302 to be incident entirely or partially from the inside of the planar shape, and not only transmission / scattering but also optical phenomena such as diffraction and refraction. Can be used. However, in the case of considering the application of a display lighting device, a normally transparent light guide is preferable from the viewpoint of guiding incident light far and efficiently emitting light from the light guide 310. Hereinafter, description will be made using a normally transparent light guide.

  Next, partial driving will be described. FIG. 8 is a diagram illustrating an example of partial driving of the planar light source device according to the second embodiment. The planar light source device 300 is a planar light source so that light is emitted from the region (2) of the light guide 310. It is controlled by the device driving unit 500.

The light modulation layer 320 corresponding to the region (1) of the light guide 310 is in a state where no voltage difference is generated between the electrodes corresponding to the region (1) (no voltage applied state), and FIG. This is a transmission state corresponding to.
The light modulation layer 321 corresponding to the region (2) of the light guide 310 is in a state where a voltage difference is generated between the electrodes corresponding to the region (2) (voltage application state), and FIG. The corresponding scattering state.

The light L4 emitted from the sidelight light source 302 enters from the side surface of the light guide 310, repeats total reflection between the transparent substrate 311 and the transparent substrate 318, and proceeds in the horizontal direction of FIG.
Since the light modulation layer 320 is in a state in which no voltage is applied, the directions of the optical axes of the liquid crystalline monomer 314a and the liquid crystalline molecule 314b coincide with each other, and there is almost no difference in refractive index. Therefore, the light L4 incident on the region (1) corresponding to the light modulation layer 320 is transmitted without being scattered and proceeds in the horizontal direction (region (2) side). That is, no light is emitted from the emission surface of the region (1) including the light modulation layer 320 controlled to be in the state of no voltage application.

  Since the light modulation layer 321 is in a voltage application state, the directions of the optical axes of the liquid crystalline monomer 314a and the liquid crystalline molecule 314b are different, and the refractive index difference increases in all directions. Therefore, the light L4 incident on the region (2) corresponding to the light modulation layer 321 is scattered. A part of the light L4 scattered toward the image display panel 200 is emitted from the light guide 310. As a result, light is emitted to the image display panel 200 from the region (2) including the light modulation layer 321 controlled to the voltage application state. Further, a part of the scattered light L4 that travels toward the reflection sheet 330 is emitted from the light guide 310, reflected by the reflection sheet 330, returned to the inside of the light guide 310, and image display of the light guide 310. The light is emitted from the panel 200 side. Therefore, the brightness | luminance radiate | emitted from the output surface of the light guide 310 can be raised by arrange | positioning the reflective sheet 330. FIG.

  As described above, the planar light source device driving unit 500 generates an electric field in the light modulation layer due to the voltage difference between the electrodes corresponding to each region, thereby scattering light in the light modulation layer corresponding to each region and guiding the light. Light can be emitted from any region of the emission surface of the body 310.

Next, a functional configuration example included in the display device 100 including such a configuration will be described with reference to FIG. FIG. 9 is a diagram illustrating a functional configuration example included in the display device according to the second embodiment.
The display device 100 includes an image output unit 110, a signal processing unit 120, an image display panel 200, a planar light source device 300, an image display panel driving unit 400, and a planar light source device driving unit 500.

  The image output unit 110 outputs the image signal to the signal processing unit 120. In the image signal, color information (information of an image displayed on the display unit) corresponding to each pixel 201 of the image display panel 200 is set.

  The signal processing unit 120 is connected to an image display panel driving unit 400 that drives the image display panel 200 and a planar light source device driving unit 500 that drives the planar light source device 300. The signal processing unit 120 generates a display signal to be displayed on the image display panel 200 based on the image signal, and outputs the display signal to the image display panel driving unit 400. Further, the signal processing unit 120 generates a light source control signal for driving the planar light source device 300 based on the image signal, and outputs the light source control signal to the planar light source device driving unit 500.

  The image display panel 200 performs display using a divided area obtained by dividing the display surface as a display unit. This display unit is a pixel 201. For example, P × Q pixels 201 are arranged in a matrix to form a display surface.

  The pixel 201 includes three subpixels of red (R), green (G), and blue (B). Note that red (R), green (G), and blue (B) are examples, and for example, one sub-pixel may be configured by four sub-pixels added with white, and other colors such as cyan, magenta, and yellow may be used. You may comprise by the color of.

  The image display panel driving unit 400 includes a signal output circuit 410 and a scanning circuit 420, and drives the image display panel 200. The image display panel driving unit 400 selects the pixel 201 by sequentially outputting the scanning signal based on the display signal from the scanning circuit 420, and sequentially outputs the video signal based on the display signal from the signal output circuit 410. The operation (light transmittance) of the pixel 201 is controlled.

  The planar light source device 300 is disposed on the back surface of the image display panel 200 and emits light toward the image display panel 200. The planar light source device 300 is arranged such that the scanning direction of the scanning circuit of the image display panel 200 (the direction from the top to the bottom in FIG. 9) and the light traveling direction of the sidelight light source 302 are parallel. That is, in the planar light source device 300, video scanning based on video signals is sequentially performed from a portion (pixel 201) corresponding to the region (1) of the light guide 310 of the image display panel 200.

  The planar light source device driving unit 500 includes a light source driving circuit 510 and a light modulation driving circuit 520. Based on the light source control signal output from the signal processing unit 120, the light source driving circuit 510 controls the output of light emitted from the sidelight light source 302 of the planar light source device 300. The light modulation driving circuit 520 controls the strength of the electric field generated between the upper electrode 312 and the lower electrode 317 and the length of time for generating the electric field. Thereby, the planar light source device driving unit 500 controls the luminance of light on the emission surface of the planar light source device 300 (light guide 310).

  The processing operation of the signal processing unit 120 is realized by the display driver IC 100b and the LED driver IC 100c or the CPU 100a1 shown in FIG. When realized by the display driver IC 100b, an input signal is input to the display driver IC 100b and the LED driver IC 100c via the CPU 100a1. The display driver IC 100b generates a display signal and controls the image display panel 200. Further, a light source control signal is generated and output to the LED driver IC 100c via the bus 100f.

  When realized by the CPU 100a1, a display signal is input from the CPU 100a1 to the display driver IC 100b. A light source control signal is also generated by the CPU 100a1 and output to the LED driver IC 100c via the bus 100f.

Next, a functional configuration example further provided in the signal processing unit 120 of the display device 100 will be described with reference to FIG. FIG. 10 is a diagram illustrating a functional configuration example of the signal processing unit included in the display device according to the second embodiment.
The signal processing unit 120 includes an image analysis unit 121, a light source data storage unit 122, a drive pattern determination unit 123, an image processing unit 124, and a timing generation unit 125. An image signal is input from the image output unit 110 to the signal processing unit 120.

  The image analysis unit 121 analyzes the image signal and requests the required luminance value of light emitted from each region of the light guide 310 of the planar light source device 300 based on the image displayed on the image display panel 200 (hereinafter, each The required brightness value of the area is calculated. The required luminance value is a luminance value required for emitted light, and the planar light source device 300 is controlled to satisfy the required luminance value.

  The image analysis unit 121 analyzes the image signal before one image display frame, and calculates the required luminance value of each region of the light guide 310 in the one image display frame from the image before the one image display frame. For example, the image analysis unit 121 analyzes an image signal before one image display frame and calculates a required luminance value of the entire exit surface. The required brightness value of the entire exit surface may be a fixed value set in advance. Further, the image analysis unit 121 analyzes an image signal corresponding to each area before one image display frame (a signal necessary for determining an image to be displayed in a portion corresponding to each area of the image display panel 200). The required luminance value for each area may be calculated.

Alternatively, every time an image signal corresponding to each area of one image display frame is input, the image analysis unit 121 analyzes the input image signal corresponding to each area, and the required luminance value of light in each area Is calculated.
Note that the image analysis unit 121 may calculate the required luminance value for each block of a two-dimensional array in which each region is divided in parallel with the light traveling direction.

  The light source data storage unit 122 sets all the light sources 303a to 303j to a predetermined lighting pattern, and controls the upper electrode 312 and the lower electrode 317 corresponding to each region with a predetermined voltage application pattern (generates a predetermined electric field for a predetermined time). Brightness distribution information is stored.

  When all the light sources 303a to 303j are turned on with a predetermined lighting amount, and an electric field having a predetermined intensity is generated in a light modulation layer corresponding to each area in a time-division manner for a predetermined time, the area is directed toward the image display panel 200. The luminance value of the emitted light is stored as luminance distribution information. The light source data storage unit 122 stores luminance distribution information (light source lookup table) in which the luminance values of light are set in a table format.

  Since the light source lookup table is information unique to the display device 100, it is created in advance and stored in the light source data storage unit 122. Note that as the luminance distribution information, the display surface of the image display panel 200 (or the exit surface of the planar light source device 300) is m × n (m, n is an arbitrary value satisfying 1 ≦ m ≦ P and 1 ≦ n ≦ Q). The brightness value of the planar light source device 300 detected for each divided region may be stored.

  The drive pattern determination unit 123 determines the lighting pattern of the sidelight light source 302 and the voltage application pattern to the upper electrode 312 and the lower electrode 317 based on the required luminance value of each region and the light source lookup table stored in the light source data storage unit 122. To decide.

  The drive pattern determination unit 123 corrects the difference between the required luminance value of each region and the luminance value of each region set in the light source lookup table by changing the light emission output of the sidelight light source 302 and voltage application. Determine the pattern.

  The drive pattern determination unit 123 controls the difference between the required luminance value of each region and the luminance value of each region set in the light source lookup table so that the light modulation layer corresponding to each region is in a scattering state (generates an electric field). The lighting pattern and the voltage application pattern corrected by changing the length of time are determined.

  The drive pattern determination unit 123 calculates the difference between the required luminance value of each region and the luminance value of each region set in the light source lookup table by the degree of scattering (the electric field to be generated) in the scattering state of the light modulation layer corresponding to each region. The lighting pattern and the voltage application pattern corrected by changing the intensity are determined.

  An example of a drive pattern including such lighting patterns for the light sources 303a to 303j and application patterns for the upper electrode 312 and the lower electrode 317 of the light guide 310 will be described later.

The image processing unit 124 generates a display signal based on the image signal.
The timing generation unit 125 generates a timing signal for controlling the timing of controlling the light modulation layer corresponding to each area of the planar light source device 300 by the planar light source device driving unit 500 to a scattering state (hereinafter, emission scanning). The timing generation unit 125 generates a timing signal corresponding to the output timing of the display signal from the image processing unit 124.

Next, a driving pattern in the case where the image signal before one image display frame is analyzed and the image analysis unit 121 calculates the required luminance value of the entire emission surface will be described with reference to FIGS.
FIG. 11 is a diagram illustrating a drive pattern in which the light emission output of the sidelight light source according to the second embodiment is changed. FIG. 12 is a diagram illustrating a drive pattern in which the electric field strength of the second embodiment is changed. FIG. 13 is a diagram illustrating a drive pattern in which the length of time for generating an electric field according to the second embodiment is changed.

As illustrated in FIG. 11, t ₁ to t ₆ are periods in which the planar light source device 300 drives the light modulation layer corresponding to each region in a scattering state and emits light from each region in one image display frame. . For example, t _{1 to} t ₆ are set by dividing one image display frame in accordance with a region. t ₁ is a period during which light is emitted from the region (1). Similarly, t _{2 to} t ₆ are periods in which light is emitted from the regions (2) to (6). The LED current is a value of a current supplied to the light sources 303a to 303j of the sidelight light source 302. When the LED current value increases, the light emission output of the sidelight light source 302 increases. Note that the same current is supplied to the light sources 303a to 303j.

  Normally, when incident light is simply incident on the side surface of the light guide 310 from the sidelight light source 302, the brightness of the light is attenuated as the light travels in the light guide 310 (away from the incident side surface). For this reason, if all the regions are controlled in the same control mode, light having uniform luminance cannot be emitted from the entire emission surface of the planar light source device 300. That is, in order to emit light having a desired luminance from each region, it is desirable to control the light attenuation depending on the distance of each region in accordance with the control corresponding to the calculation.

  Therefore, the drive pattern determination unit 123 corrects the difference between the required luminance value and the light source lookup table with the light emission output (the magnitude of the LED current) of the sidelight light source 302, and takes into account the light attenuation due to the distance. Determine the driving pattern.

  That is, the drive pattern determination unit 123 fixes the length of time for generating the electric field and the intensity of the electric field in all regions, and changes only the value of the LED current (the light emission output of the sidelight light source 302). To decide.

In the driving pattern drive pattern determination unit 123 is determined, for example, an electric field corresponding to the voltage difference v between electrodes occurs through the period in the light modulation layer corresponding to the area (1) in the period t _1, sidelight source 302 Light of an output corresponding to the LED current i ₁ is emitted.

Further, in the period t ₂ , an electric field corresponding to the voltage difference v between the electrodes is generated in the light modulation layer corresponding to the region (2) throughout the period, and the sidelight light source 302 corresponds to the LED current i ₂ (> i ₁ ). Emits output light. Similarly, in the period t _{2 to} t ₆ , an electric field corresponding to the voltage difference v between the electrodes is generated in the light modulation layer corresponding to the regions (2) to (6) throughout the period, and the sidelight light source 302 generates the LED current i _2. ˜i ₆ (i ₁ <i ₂ <i ₃ <i ₄ <i ₅ <i ₆ ) is emitted.

  Thus, by controlling the magnitude of the LED current according to the distance to the sidelight light source 302 in the region, the planar light source device 300 corrects the light attenuation according to the distance by the light emission output of the sidelight light source 302. it can. Thereby, the planar light source device 300 suppresses the intensity of the light emitted from each area from deviating from the required intensity due to the attenuation of the light due to the distance, and the desired intensity from each area to the image display panel 200. Luminous light can be emitted.

  Alternatively, as shown in FIG. 12, the drive pattern determination unit 123 corrects the difference between the required luminance value and the light source lookup table by the degree of scattering (electric field strength) in the scattering state of the light modulation layer. It is also possible to determine a drive pattern that takes into account the light attenuation due to.

  That is, the drive pattern determination unit 123 fixes the length of time for generating the electric field and the light emission output of the sidelight light source 302 in the scattering state of the light modulation layer in the entire region, and the voltage difference between the electrodes (the electric field strength). The driving pattern is determined by changing only (a).

In the driving pattern determined by the driving pattern determination unit 123, for example, an electric field corresponding to the voltage difference v ₁ between the electrodes is generated in the light modulation layer 314 corresponding to the region (1) in the period t ₁ , and the sidelight light source is generated. 302 emits light having an output corresponding to the LED current i. Further, in the period t ₂ , an electric field corresponding to the voltage difference v ₂ (> v ₁ ) between the electrodes is generated in the light modulation layer 314 corresponding to the region (2) throughout the period, and the sidelight light source 302 corresponds to the LED current i. The light of the output to be emitted is emitted. Similarly, the voltage difference between the electrodes v _{3 to} v ₆ (v ₂ <v ₃ <v ₄ <v ₅ ) through the light modulation layer corresponding to the region (3) to the region (6) during the period t _{3 to} t ₆ . An electric field corresponding to <v ₆ ) is generated, and the sidelight light source 302 emits light having an output corresponding to the LED current i. The larger the voltage difference between the electrodes, the stronger the electric field generated, the higher the degree of scattering in the scattering state of the light modulation layer corresponding to the region, and the more light is extracted.

  In this way, by controlling the magnitude of the voltage difference between the electrodes corresponding to the region according to the distance to the sidelight light source 302 in the region, the planar light source device 300 emits light attenuation according to the distance. Correction can be made by the degree of scattering of the modulation layer. Thereby, the planar light source device 300 prevents the intensity of the light emitted from each area from deviating from the required intensity due to the attenuation of the light due to the distance, and the image display panel 200 from each area of the emission surface. Thus, light having a desired luminance can be emitted.

  Alternatively, as shown in FIG. 13, the drive pattern determination unit 123 corrects the difference between the required luminance value and the light source lookup table by the length of time for controlling the light modulation layer in the scattering state, and thereby the light according to the distance. It is also possible to determine a drive pattern that takes into account the attenuation of.

  That is, the drive pattern determination unit 123 fixes the intensity of the electric field and the light emission output of the sidelight light source 302 in the scattering state of the light modulation layer in the entire region, and generates the electric field (voltage difference between the electrodes). The drive pattern is determined by changing only the length.

In the driving pattern drive pattern determination unit 123 is determined, for example, between the light modulating layer 314 in the period T ₁ corresponding to the region (1) in the period t _1, an electric field corresponding to the voltage difference v between the electrodes occurs, The sidelight light source 302 emits light having an output corresponding to the LED current i. In addition, in the period t ₂ , an electric field corresponding to the voltage difference v between the electrodes is generated in the light modulation layer 314 corresponding to the region (2) during the period T ₂ (> T ₁ ), and the sidelight light source 302 generates the LED current. Emits light with an output corresponding to i. Similarly, during the periods T _{3 to} T ₆ (T ₂ <T ₃ <T ₄ <T ₅ <T ₆ ) in the light modulation layer 314 corresponding to the regions (3) to (6) in the period t _{3 to} t ₆ . An electric field corresponding to the voltage difference v between the electrodes is generated, and the sidelight light source 302 emits light having an output corresponding to the LED current i. Note that the light modulation layer 314 corresponding to each region extracts more light as the time in the scattering state becomes longer.

In this way, the planar light source device 300 attenuates light in accordance with the distance by controlling the length of time in which a voltage difference is generated between the electrodes in the region according to the distance to the sidelight light source 302 in the region. Can be corrected by the length of time to control the light modulation layer to the scattering state.
Thereby, the planar light source device 300 prevents the intensity of the light emitted from each area from deviating from the required intensity due to the attenuation of the light due to the distance, and the image display panel 200 from each area of the emission surface. Thus, light having a desired luminance can be emitted.

  In the above description, the case where uniform light is emitted from the entire exit surface (the case where the image analysis unit 121 calculates the required brightness value of the entire exit surface) has been described, but light having different luminance is emitted for each region. The same applies to the case. Further, the planar light source device 300 supplies different LED currents for the respective light sources 303a to 303j, and emits light while controlling the luminance for each block of a two-dimensional array in which each region is divided in parallel with the light traveling direction. The same applies to the case.

  When the light attenuation due to distance is corrected by the light emission output of the sidelight light source 302, when the light attenuation due to distance is corrected by the strength of the electric field, the light attenuation due to distance depends on the length of time for generating the electric field. Although the case where it correct | amended was demonstrated, each can also be used together.

  Next, the timing of the emission scanning for controlling the light modulation layer corresponding to each region to the scattering state and the video scanning of the pixel 201 corresponding to each region of the image display panel 200 will be described with reference to FIG. FIG. 14 is a diagram illustrating the timing of the emission scanning and the image scanning according to the second embodiment, which is the timing of the emission scanning and the image scanning when the planar light source device 300 is moved by the drive pattern of FIG.

The video scanning of the image display panel 200 ends for all pixels (hereinafter, pixel (1)) corresponding to the region (1) of the image display panel 200 when d _{1 has} elapsed from the start, and when d _{2 has} elapsed, the image display panel The process is completed for all the pixels corresponding to the region (2) of 200 (hereinafter, pixel (2)). Similarly, the video scanning of the image display panel 200 is performed for all pixels (hereinafter, pixels (3) to (6)) corresponding to the regions (3) to (6) of the image display panel 200 after d _{3 to} d _{6 have} elapsed. Exit for. Then, the video scanning of the image display panel 200 in one image display frame ends when d _{6 has} elapsed from the start. Then, after the V blank period, video scanning of the next one image display frame starts.

  Based on the timing signal, the planar light source device driving unit 500 emits light (corresponding to the region) so that the time for emitting light from each region is after all the video scanning for the pixels corresponding to the region is completed. The light modulation layer is controlled to be in a scattering state). That is, the planar light source device driving unit 500 controls the planar light source device 300 so as not to perform emission scanning of the region while image scanning is performed on the region.

For example, the planar light source device driving unit 500 starts emission scanning of one image display frame after d ₁ has elapsed from the start of video scanning in the one image display frame, and d from the start of video scanning of the next one image display frame. After ₁ lapse, the exit scanning of the next one image display frame is started.

  Specifically, the planar light source device driving unit 500 starts video scanning of the pixel (1) in the next one image display frame after the video scanning of all the pixels (1) in one image display frame is completed. Before, the emission scanning is performed on the region (1) in the one image display frame.

  The planar light source device driving unit 500 performs the 1st scanning after the video scanning of all the pixels (2) in one image display frame is completed and before the video scanning of the pixel (2) in the next one image display frame is started. Outgoing scanning is performed on the region (2) in the image display frame. Similarly, the planar light source device driving unit 500 completes the image scanning of the pixels (3) to (6) in the one image display frame and the pixels (3) to (6) in the next one image display frame. ), The emission scanning is performed on the areas (3) to (6) in the one image display frame.

  According to such video scanning and emission scanning timing, the emission scanning of each area can be reliably performed after the video scanning of the pixels 201 corresponding to each area of the image display panel 200 is completed. Therefore, the display device 100 can prevent the pixel 201 from being irradiated with light while the pixel 201 of the image display panel 200 is scanned. Thereby, the display apparatus 100 can suppress moving image blur.

  Further, according to the timing described above, the drive pattern determination unit 123 outputs the image signal corresponding to each input region every time the image analysis unit 121 inputs the image signal corresponding to each region of one image display frame. The drive pattern can also be determined using the required brightness value of the light of each region calculated by analysis.

  Since the image signals are input sequentially, the image of the portion corresponding to each area of the image display panel 200 in the one image display frame is not fixed at the start of video scanning of the one image display frame. Therefore, at the start of video scanning of one image display frame, the image analysis unit 121 cannot analyze the image signal corresponding to each area of the one image display frame and calculate the required luminance value of each area.

  However, by performing the emission scanning of each area in one image display frame after the video scanning of the pixels 201 corresponding to each area of the image display panel 200 in the one image display frame is completed, the image analysis unit 121 includes: An image signal corresponding to each area is input before the emission scanning of each area.

  Therefore, the image analysis unit 121 can analyze the image signal corresponding to each area of the one image display frame and calculate the required luminance value of each area before the emission scanning of each area in the one image display frame. . As a result, the drive pattern determination unit 123 acquires the required brightness value of each region calculated by the image analysis unit 121 analyzing the image of the portion corresponding to each region before the emission scan, and the drive pattern of each region. Can be determined.

In other words, the drive pattern determination unit 123 is more appropriate for the image displayed in the one image display frame than the required luminance value of each region calculated by the image analysis unit 121 analyzing the image signal before one image display frame. The drive pattern can be determined using the required luminance value of the region. Thereby, the display apparatus 100 can improve image quality.
[Third Embodiment]

  Next, a display device according to a third embodiment will be described. In the display device according to the third embodiment, the planar light source device driving unit emits light emitted from a part of the emission surface and other regions based on the analysis result of the image signal of the image analysis unit. Increase the difference between light and darkness (dynamic range).

For example, the image analysis unit determines that the required luminance value of the area is a value at the time of white display (maximum luminance value), and the difference in luminance from the required luminance value of the area around the area is equal to or greater than a predetermined value. In some cases, a luminance value higher than the value for white display is requested as the required luminance value of the area.
The configuration of the display device of the third embodiment is the same as that of the display device 100 of the second embodiment. In addition, the same number is attached | subjected to the same thing as 2nd Embodiment, and description is abbreviate | omitted.

  A driving pattern for increasing the difference in brightness between light emitted from a part of the emission surface of the planar light source device 300 and light emitted from another area will be described with reference to FIGS. FIG. 15 is a diagram showing a drive pattern in the case where the difference in brightness between light emitted from a partial region of the emission surface of the third embodiment and light emitted from another region is increased. Shows a case where light having high emission brightness is emitted from the region (3). FIG. 16 is a modification of the mode of the voltage difference between the electrodes in the overlap portion of the third embodiment.

The drive pattern determination unit 123 sets the periods t _{1 to} t ₆ in a time-sharing manner, generates a period for generating an electric field in the region (3), and sets a period t _L in the period t ₄ for generating an electric field in the region (4). Determine the overlapped drive pattern.

In the driving pattern drive pattern determining unit 123 has determined, sidelight source 302 emits a light output corresponding to the LED current I _L in the period t _L. The value of the LED current I _L is determined so that the luminance corresponding to the difference between the luminance required for the region (3) and the luminance satisfied by the period t _{3 is} satisfied during the period t _L. 123. For example, the drive pattern determination unit 123 determines the LED current I _L to be larger than any value of the LED currents i _{1 to} i ₆ . As a result, the drive pattern determining unit 123 can reduce the time period t _L overlapping.

In the driving pattern drive pattern determining unit 123 has determined, in the period t ₄ when sidelight source 302 after lapse of the period t _L of the period t ₄ is the LED current I ₄ (> i ₄ where (not only overlap period t _L The light of the output corresponding to the LED current)) is emitted. This is because in the period t _L , light is emitted from the area (3) closer to the side light source 302 than the area (4), and thus the period t _L does not contribute much to the luminance of the area (4).

  If it drives with such a drive pattern, the planar light source device 300 can make the brightness | luminance of the light radiate | emitted from area | region (3) brighter, satisfy | filling the required luminance value of each area | region, and the light radiate | emitted from area | region (3). And the difference (dynamic range) of light and dark with the light radiate | emitted from another area | region can be enlarged.

  Although the case where light attenuation due to distance is corrected by the light emission output of the sidelight light source 302 has been described, when light attenuation due to distance is corrected by electric field strength, light attenuation due to distance generates an electric field. Even when the correction is made according to the length of time to be performed, the same can be realized.

The driving pattern determination unit 123, as shown in FIG. 16 (a), than the voltage difference v between the voltage difference v _L the duration t ₃ electrodes between the electrodes corresponding to the region (3) in the period t _L A driving pattern to be reduced may be determined. By driving with such a driving pattern, the scattering degree of the light modulation layer in the period t _L becomes smaller than the scattering degree of the light modulation layer in the period t ₃ .
Thus, by controlling the value of the voltage difference v _L between the electrodes corresponding to the region (3), the drive pattern determination unit 123 can control the luminance of the light emitted from the region (4) in the period t _L. That is, the drive pattern determination unit 123 makes the voltage difference v _L between the electrodes corresponding to the region (4) smaller than the voltage difference v, thereby reducing the value of the LED current I ₄ that flows to satisfy the required luminance value. can do.

Furthermore, drive pattern determining unit 123, as shown in FIG. 16 (b), may determine the drive pattern generating a voltage difference v between the electrodes in the PWM driving in the region (3) in the period t _L. By driving with such a drive pattern, the state (scattering state, transmission state) of the light modulation layer corresponding to the region (3) is alternately switched at a predetermined interval in the period t _L. In this way, by generating the voltage difference v between the electrodes by PWM driving in the region (3), the drive pattern determination unit 123 controls the luminance of the light emitted from the region (4) in the period t _L to request The value of the LED current I ₄ that flows to satisfy the luminance value can be reduced. Note that the drive patterns shown in FIGS. 16A and 16B can be used in combination.

  The above processing functions can be realized by a computer. In that case, a program describing the processing contents of the functions that the display device should have is provided. By executing the program on a computer, the above processing functions are realized on the computer. The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include a magnetic storage device, an optical disk, a magneto-optical recording medium, and a semiconductor memory. Examples of the magnetic storage device include a hard disk drive (HDD), a flexible disk (FD), and a magnetic tape. Optical discs include DVD (Digital Versatile Disc), DVD-RAM, CD (Compact Disc) -ROM, CD-R (Recordable) / RW (ReWritable), and the like. Magneto-optical recording media include MO (Magneto-Optical disk).

  When distributing the program, for example, a portable recording medium such as a DVD or a CD-ROM in which the program is recorded is sold. It is also possible to store the program in a storage device of a server computer and transfer the program from the server computer to another computer via a network.

The computer that executes the program stores, for example, the program recorded on the portable recording medium or the program transferred from the server computer in its own storage device. Then, the computer reads the program from its own storage device and executes processing according to the program. The computer can also read the program directly from the portable recording medium and execute processing according to the program. In addition, each time a program is transferred from a server computer connected via a network, the computer can sequentially execute processing according to the received program.
Further, at least a part of the above processing functions can be realized by an electronic circuit such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), or a PLD (Programmable Logic Device).

  Within the scope of the idea of the present technology, those skilled in the art can conceive various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present technology. For example, those in which the person skilled in the art appropriately added, deleted, or changed the design of the above-described embodiments, or those in which the process was added, omitted, or changed the conditions are also the gist of the present technology. As long as it is provided, it is included in the scope of the present technology.

  In addition, it is understood that what is obvious from the description of the present specification or can be appropriately conceived by those skilled in the art regarding other functions and effects brought about by the aspects described in the present embodiment is brought about by the present technology. .

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 10 ... Image display panel, 20 ... Light source device, 21 ... Light source, 22 ... Light guide, 22a-22f ... area | region, 23 ... Side surface, 30 ... Control device

Claims (4)

An image display panel;
A light source that emits light and a back surface of the image display panel. The light is incident from a side surface of the surface that faces the image display panel, and is in a transmission state that transmits the light or a scattering state that scatters the light. A light source device comprising: a light guide including a controllable light modulation layer and having a plurality of regions divided in a direction intersecting a traveling direction of the light;
The light corresponding to each region is controlled by controlling the light modulation layer corresponding to each region to the scattering state during the scattering control time of the light modulation layer corresponding to each region set so as not to overlap in time. The scattering state of the modulation layer is controlled so as to temporally overlap a part of the scattering control time corresponding to the region that is farther from the side surface than the region, and the light modulation layer is and a control unit for controlling the light source device in the driving pattern in accordance with the distance from the side surface of the region including the light modulation layer in controlling the scattering state possess,
When the control device raises the luminance of the emitted light emitted from the region to the image display panel higher than the luminance of the emitted light emitted from the region around the region to the image display panel. In addition, the scattering state of the light modulation layer corresponding to the region overlaps with a part of the scattering control time of the light modulation layer corresponding to the region which is farther from the side surface than the region. To control,
Display device. The control device includes an analysis unit that analyzes an image signal supplied to the image display panel,
Based on the analysis result of the image signal by the analysis unit, the scattering state of the light modulation layer corresponding to the region is determined based on the scattering state of the light modulation layer corresponding to the region farther from the side surface than the region. Determining the region to overlap in time with a portion of the scattering control time;
The display device according to claim 1 . The control device temporally overlaps the light modulation layer corresponding to the region with a part of the scattering control time of the light modulation layer corresponding to the region farther from the side surface than the region. In the case of controlling to the scattering state, while being overlapped, the scattering state and the transmission state are alternately switched at a predetermined interval.
The display device according to claim 1 or 2. The control device temporally overlaps the light modulation layer corresponding to the region with a part of the scattering control time of the light modulation layer corresponding to the region farther from the side surface than the region. When controlling to the scattering state, the scattering degree of the scattering state of the light modulation layer corresponding to the region while being overlapped is the scattering degree of the scattering state in the scattering control time of the light modulation layer. Control to be lower,
Display device according to any one of claims 1 to 3.

Images