JP2009021037A - Surface light source device and liquid crystal display device assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface light source device in which wrinkles do not occur in an optical functional sheet even when the optical functional sheet expands by a thermal expansion and the optical functional sheet does not contact a liquid crystal display device and, furthermore, a gap existing between the optical functional sheet and the liquid crystal display device can be made as narrow as possible. <P>SOLUTION: The surface light source device 20 which illuminates a liquid crystal display device of a transmission type arranged in the front is provided with a case 30, a light source, a light diffusion plate, and an optical functional sheet 51 which is arranged in front of the light diffusion plate and installed at the upper part 32 of the front section in a state hung down from the upper part 32 of the front section of the case 30, and transmits the light emitted from the light diffusion plate, and is further provided with linear members 40 which are arranged in front of the optical functional sheet 51 and of which end parts are installed at both side parts 34, 35 of the front section of the case 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a planar light source device (so-called backlight) that illuminates a transmissive liquid crystal display device from the back, and a liquid crystal display device assembly incorporating the planar light source device.

  In the liquid crystal display device, the liquid crystal material itself does not emit light. Therefore, for example, a direct-type planar light source device (backlight) that illuminates the display area of the liquid crystal display device is disposed behind the display area composed of a plurality of pixels. In the color liquid crystal display device, one pixel includes, for example, three types of sub-pixels: a red light-emitting subpixel, a green light-emitting subpixel, and a blue light-emitting subpixel. Then, by operating the liquid crystal cell constituting each pixel or each sub-pixel as a kind of light shutter (light valve), that is, controlling the light transmittance (aperture ratio) of each pixel or each sub-pixel, An image is displayed by controlling the light transmittance of illumination light (for example, white light) emitted from the planar light source device.

A planar light source device disposed behind the liquid crystal display device and having a vertical light emission surface is, for example,
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate and transmits light emitted from the light diffusing plate;
It has.

  Since the light diffusion plate and the optical function sheet have different coefficients of thermal expansion, when the light diffusion plate and the optical function sheet are heated by a light source that is lit, the light diffusion plate and the optical function sheet expand with different elongation amounts. When the optical diffusion sheet and the optical functional sheet are in close contact with each other or the optical functional sheet cannot move freely, the optical functional sheet is wrinkled because the amount of extension is different. As a result, there is a problem that a shadow is reflected on the liquid crystal display device and the luminance of the display screen becomes non-uniform.

  Therefore, for example, a schematic view of the optical function sheet 51 as viewed from the front (liquid crystal display device side) of the planar light source device 120 is shown in FIG. It is attached to the housing upper part 32 in a state of being suspended from the housing upper part 32, and has a structure in which no wrinkles are generated in the optical functional sheet 51 even when the optical functional sheet 51 is extended by thermal expansion. More specifically, a plurality of holes are provided in the upper end portion of the optical function sheet 51, and a pin 38 that engages with the hole is attached to the housing upper part 32, and the pin 38 and the hole are engaged. By doing so, the optical function sheet 51 is suspended from the housing upper part 32. Therefore, no external force is applied in the thickness direction of the optical function sheet 51, and the optical function sheet 51 is disposed on the back side of the optical function sheet 51 in FIG. It is held so that it can freely expand and contract with respect to the functional sheet 51.

  Alternatively, a liquid crystal display device having a structure in which wrinkles are not generated in an optical function sheet by attaching the optical function sheet to a mold frame using a positioner is disclosed in JP-A-11-281966.

JP-A-11-281966 JP-A-2005-258403

  Usually, a gap of about 10 mm is provided between the optical function sheet 51 and the liquid crystal display device. In the conventional technique, as described above, the optical function sheet 51 is held so that it can freely expand and contract with respect to the light diffusion plate. Therefore, when the optical function sheet 51 is expanded by thermal expansion, Although the optical function sheet 51 is not wrinkled, it may come into contact with the liquid crystal display device. When such a phenomenon occurs, there arises a problem that the luminance of the display screen becomes non-uniform.

  Conventionally, a planar light source device in a liquid crystal display device assembly illuminates the entire display area with uniform and constant brightness. However, the planar light source device has a configuration different from such a planar light source device, that is, a plurality of planar light source devices. A planar light source device (partial drive type or split drive type planar light source device) having a configuration that changes the distribution of illuminance in a plurality of display area units is disclosed in, for example, 258403 is known. By controlling the planar light source device (also referred to as partial driving or divided driving of the planar light source device), it is possible to increase the white level and increase the contrast ratio due to the black level decrease in the liquid crystal display device. As a result, the quality of image display can be improved and the power consumption of the planar light source device can be reduced.

  In such a partial drive type planar light source device, a certain planar light source unit (referred to as a planar light source unit-A for convenience and a display area unit corresponding to the planar light source unit-A is referred to as a display area unit-A). Is a planar light source unit adjacent to the planar light source unit-A (referred to as a planar light source unit-B for convenience, and a display area unit corresponding to the planar light source unit-B is a display area) Assume that these planar light source units are controlled in a state where the luminance of the unit-B) is low. In such a case, in principle, the image displayed in the display area unit-B becomes dark. However, when the portion of the display area unit-B adjacent to the display area unit-A is viewed obliquely, a gap of about 10 mm is provided between the optical function sheet 51 and the liquid crystal display device. As shown in the conceptual diagram in FIG. 15B, there may arise a problem that the portion of the display area unit-B appears bright due to the light emitted from the high-luminance planar light source unit-A. Further, as shown in the simulation result in FIG. 16, there is a difference in luminance between when the image displayed on the liquid crystal display device is viewed from the front (front view) and when viewed from an oblique direction (non-front view). In FIG. 16, “distance between LC and BL” means a distance between the planar light source device and the liquid crystal display device. Such a problem is referred to as a “parallax problem” for convenience of explanation. Therefore, it is desirable that the gap existing between the optical function sheet 51 and the liquid crystal display device is as narrow as possible.

  Accordingly, an object of the present invention is to prevent wrinkling of the optical functional sheet, contact with the liquid crystal display device, and contact between the optical functional sheet and the liquid crystal display device even when the optical functional sheet is expanded by thermal expansion. An object of the present invention is to provide a planar light source device that can make an existing gap as narrow as possible and hardly cause a parallax problem, and a liquid crystal display device assembly incorporating such a planar light source device.

In order to achieve the above object, a planar light source device of the present invention is a planar light source device that illuminates a transmissive liquid crystal display device disposed in front of the planar light source device.
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
With
(E) a linear member that is disposed in front of the optical function sheet and has ends attached to both sides of the front surface of the housing;
Is further provided.

The liquid crystal display device assembly according to the first aspect of the present invention for achieving the above object includes a transmissive liquid crystal display device and a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
The planar light source device comprises:
(E) a linear member that is disposed in front of the optical function sheet and has ends attached to both sides of the front surface of the housing;
Is further provided.

  In the planar light source device of the present invention or the liquid crystal display device assembly according to the first aspect of the present invention (hereinafter collectively referred to as the first aspect of the present invention), the linear member (wire) is It is preferable to extend in the horizontal direction. The number of the linear members may be at least one and may be two or more. Moreover, you may further provide the 2nd linear member arrange | positioned ahead of the optical function sheet | seat, and the edge part was attached to the upper part and lower part of the front part of a housing | casing. Here, it is preferable that the second linear member extends in the vertical direction. The number of second linear members may be at least one and may be two or more. Examples of the material constituting the linear member or the second linear member include a wire made of metal or alloy, a wire made of chemical fiber, and a wire made of plastic. The thickness (diameter) of the linear member or the second linear member is such that the linear member or the second linear member receives light from the light source, so that the linear member is viewed by an observer who views the image on the liquid crystal display device. Alternatively, it is desirable that the thickness (diameter) at which the shadow of the second linear member is not recognized, or the thickness (diameter) at which it is difficult to recognize, for example, 10 μm to 50 μm. The linear member or the second linear member may be attached so that the linear member or the second linear member and the optical function sheet are always in contact with each other. When placed in the state, the linear member or the second linear member may be attached so that the linear member or the second linear member and the optical function sheet are in contact with each other. The attachment of the linear member or the second linear member to the front surface portion of the housing may be performed by an appropriate method.

A liquid crystal display device assembly according to a second aspect of the present invention for achieving the above object is a transmissive liquid crystal display device and a liquid crystal display device assembly including a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate and transmits light emitted from the light diffusing plate;
With
The optical function sheet is suspended from the upper part of the support panel provided in the liquid crystal display device via the optical function sheet mounting means.
The distance between the liquid crystal display device and the optical function sheet is controlled by the operation of the optical function sheet mounting means.

In the liquid crystal display device assembly according to the second aspect of the present invention,
The optical function sheet mounting means consists of a bimetal plate,
As a result of the temperature of the optical function sheet mounting means rising due to the heat generated by the light source, the shape of the optical function sheet mounting means changes, so that the optical function sheet can be moved away from the liquid crystal display device. .

A liquid crystal display device assembly according to a third aspect of the present invention for achieving the above object is a transmissive liquid crystal display device and a liquid crystal display device assembly including a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
With
A light diffusion sheet is disposed on the surface of the liquid crystal display device facing the planar light source device.

  In the liquid crystal display device assembly according to the third aspect of the present invention, specifically, for example, by adhering a light diffusion sheet on a polarizing plate constituting a surface of the liquid crystal display device facing the planar light source device. A light diffusion sheet can be arranged on the surface of the liquid crystal display device facing the planar light source device. The term “polarizing plate” includes a polarizing film or a polarizing sheet.

A liquid crystal display device assembly according to a fourth aspect of the present invention for achieving the above object is a transmissive liquid crystal display device and a liquid crystal display device assembly including a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
With
The surface of the liquid crystal display device facing the planar light source device is composed of a polarizing plate,
The polarizing plate has a light diffusion function. The term “polarizing plate” includes a polarizing film or a polarizing sheet.

  In the liquid crystal display device assembly according to the fourth aspect of the present invention, the polarizing plate has a light diffusing function. Specifically, the light diffusing material is provided on the outer surface of the polarizing plate (polarizing film / polarizing sheet). The structure to which is fixed can be mentioned. Here, examples of the material constituting the light diffusing material include fine particles obtained by forming a plastic material such as PMMA into a particle shape. As a method for fixing the light diffusing material to the polarizing plate, a mixture of a binder and the light diffusing material is used. The method of apply | coating to a polarizing plate and solidifying a binder can be mentioned.

  The planar light source device of the present invention including the above-described preferred configuration, the liquid crystal display device assembly according to the first to fourth aspects of the present invention (hereinafter, these may be collectively referred to simply as the present invention). In some cases, a plurality of light sources may be simultaneously driven under the same driving conditions and under certain driving conditions. Alternatively, a plurality of light sources may be partially driven. That is, when the planar light source device is assumed to divide the display area of the liquid crystal display device into P × Q virtual display area units, P × Q pieces corresponding to these P × Q display area units are used. The light emission states of the P × Q planar light source units may be individually controlled.

  In the present invention including the preferred configuration described above, the light source can be composed of, for example, a light emitting diode (LED). However, the present invention is not limited to this, and a cold cathode ray fluorescent lamp or electroluminescence (EL) ) Devices, cold cathode field electron emission devices (FED), plasma display devices, ordinary lamps, electric lamps and fluorescent lamps. When the light source is composed of a light-emitting diode, white light can be obtained by configuring a red light-emitting diode that emits red, a green light-emitting diode that emits green, and a blue light-emitting diode that emits blue. White light can also be obtained by light emission of a light emitting diode (for example, a light emitting diode that emits white light by combining ultraviolet or blue light emitting diodes and phosphor particles). Depending on the case, a light emitting diode that emits a fourth color other than red, green, blue, fifth color,... May be further provided.

  When the light source is composed of a light emitting diode, for example, a red light emitting diode that emits red with a wavelength of 640 nm, for example, a green light emitting diode that emits green with a wavelength of 530 nm, and a blue light emitting diode that emits blue with a wavelength of 450 nm, for example, When configuring, these combinations are specifically (one red light emitting diode, one green light emitting diode, one blue light emitting diode), (one red light emitting diode, two green light emitting diodes, one blue light emitting diode). Light emitting diodes), (two red light emitting diodes, two green light emitting diodes, one blue light emitting diode) and the like, but not limited thereto.

  The light-emitting diode that constitutes the light source may have a so-called face-up structure or a flip-chip structure. That is, the light-emitting diode includes a substrate and a light-emitting layer formed on the substrate, and may have a structure in which light is emitted from the light-emitting layer to the outside, or light from the light-emitting layer passes through the substrate. It is good also as a structure radiate | emitted outside. More specifically, the light emitting diode (LED) includes, for example, a first compound semiconductor layer having a first conductivity type (for example, n-type) formed on a substrate, and an active layer formed on the first compound semiconductor layer. A first electrode having a stacked structure of a second compound semiconductor layer having a second conductivity type (for example, p-type) formed on the active layer and electrically connected to the first compound semiconductor layer; A second electrode electrically connected to the two-compound semiconductor layer is provided. The layer constituting the light emitting diode may be made of a known compound semiconductor material depending on the emission wavelength.

  In the planar light source device of the present invention and the liquid crystal display device assemblies according to the first, third, and fourth embodiments of the present invention, the optical function sheet is suspended from the upper part of the front surface portion of the housing. The optical function sheet may be attached to the lower part of the front part of the housing so as to be movable in the vertical and horizontal directions, or moved in the vertical and horizontal directions. You may freely attach to the both sides of the front part of a housing | casing, and you may attach to the both sides of the front part of a housing | casing and the lower part so that it can move vertically and horizontally. For example, by attaching a pin to the upper part of the front part of the housing, providing a hole in the optical function sheet, and engaging the pin and the hole, the optical function sheet is suspended from the upper part of the front part of the housing. However, the present invention is not limited to such a method.

  In the present invention, examples of the optical functional sheet provided in the planar light source device include a light diffusion sheet, a prism sheet, and a polarization conversion sheet including a reflective polarizing film having a multilayer structure. At least one type may be attached. In the planar light source device of the present invention, the liquid crystal display device assembly according to the first, third, and fourth aspects of the present invention, the optical function sheet may be in contact with the light diffusion plate. However, it may be in a non-contact state. A reflective sheet may be attached to the inner surface of the housing. Examples of the material constituting the light diffusion plate or the light diffusion sheet include polycarbonate resin (PC), polystyrene resin (PS), and methacrylic resin.

  The housing may be made of, for example, plastic or metal, and is a box-shaped (cuboid) member having a kind of opening as a whole and having four side surfaces and one bottom surface. And this opening part opposes a liquid crystal display device, the peripheral part of this opening part is equivalent to the front part of a housing | casing, and four side surfaces correspond to the upper part of a housing | casing, a lower part, and two side parts. A light source may be attached to the base corresponding to the bottom surface. The support panel may be made of, for example, plastic or metal.

  A partition may be provided between the planar light source unit and the planar light source unit. Specific examples of the material constituting the partition include polymethyl methacrylate resin (PMMA), polycarbonate resin (PC), polyarylate resin (PAR), polyethylene terephthalate resin (PET), acrylic resin, ABS resin, and glass. It can be mentioned, It can be set as a transparent structure or an opaque structure with respect to the light radiate | emitted from the light source with which the planar light source unit was equipped. A light diffusion reflection function may be imparted to the partition wall surface, or a specular reflection function may be imparted. In order to impart a light diffusing and reflecting function to the partition wall surface, irregularities may be formed on the partition wall surface based on a sandblasting method, or a film (light diffusion film) having irregularities may be attached to the partition wall surface. In addition, in order to impart a specular reflection function to the partition wall surface, a light reflection film may be attached to the partition wall surface, or a light reflection layer may be formed on the partition wall surface by plating, for example.

  The transmissive liquid crystal display device includes, for example, a front panel having a transparent first electrode, a rear panel having a transparent second electrode, and a liquid crystal material disposed between the front panel and the rear panel. Consists of. The liquid crystal display device may be a monochrome liquid crystal display device or a color liquid crystal display device.

  More specifically, the front panel includes, for example, a first substrate made of, for example, a glass substrate or a silicon substrate, and a transparent first electrode (also called a common electrode, for example, ITO provided on the inner surface of the first substrate. And a polarizing plate (polarizing film / polarizing sheet) provided on the outer surface of the first substrate. Further, in the transmissive color liquid crystal display device, a color filter covered with an overcoat layer made of acrylic resin or epoxy resin is provided on the inner surface of the first substrate. Examples of the color filter arrangement pattern include a delta arrangement, a stripe arrangement, a diagonal arrangement, and a rectangle arrangement. The front panel further has a configuration in which a transparent first electrode is formed on the overcoat layer. An alignment film is formed on the transparent first electrode. On the other hand, the rear panel more specifically includes, for example, a second substrate made of a glass substrate or a silicon substrate, a switching element formed on the inner surface of the second substrate, and conduction / non-conduction by the switching element. A transparent second electrode to be controlled (also called a pixel electrode, made of, for example, ITO) and a polarizing plate (polarizing film / polarizing sheet) provided on the outer surface of the second substrate are configured. An alignment film is formed on the entire surface including the transparent second electrode. Various members and liquid crystal materials constituting the liquid crystal display device including these transmissive color liquid crystal display devices can be formed of known members and materials. Examples of the switching element include a three-terminal element such as a MOS type FET and a thin film transistor (TFT) formed on a single crystal silicon semiconductor substrate, and a two-terminal element such as an MIM element, a varistor element, and a diode.

  An area where the transparent first electrode and the transparent second electrode overlap and includes a liquid crystal cell corresponds to one pixel (pixel) or one sub-pixel (sub-pixel). In the transmissive color liquid crystal display device, the red light emitting sub-pixel (which may be referred to as sub-pixel [R]) constituting each pixel (pixel) transmits red light with the liquid crystal cell constituting the region. The green light emitting subpixel (sometimes referred to as subpixel [G]) is composed of a combination of a liquid crystal cell constituting the region and a color filter that transmits green light. The blue light-emitting subpixel (sometimes referred to as subpixel [B]) is composed of a combination of a liquid crystal cell that forms the region and a color filter that transmits blue light. The arrangement pattern of the sub-pixel [R], sub-pixel [G], and sub-pixel [B] matches the arrangement pattern of the color filter described above. The pixel is not limited to a configuration in which three types of sub-pixels [R, G, B], which are a sub-pixel [R], a sub-pixel [G], and a sub-pixel [B], are configured as one set. For example, a set of these three types of sub-pixels [R, G, B] plus one or more types of sub-pixels (for example, one sub-pixel that emits white light to improve brightness) To expand the color reproduction range, one set including sub-pixels that emit complementary colors to expand the color reproduction range, one set including sub-pixels that emit yellow to expand the color reproduction range It can also be composed of a set of subpixels that emit yellow and cyan.

  Here, the light transmittance (also referred to as aperture ratio) Lt of the pixel or sub-pixel, the luminance (display luminance) y of the display area corresponding to the pixel or sub-pixel, and the luminance (light source luminance) of the planar light source unit Y is defined as follows:

Y ₁ ... Is the maximum luminance of the light source luminance, for example, and may be hereinafter referred to as the light source luminance and the first specified value.
Lt ₁ ... Is the maximum value of the light transmittance (aperture ratio) of the pixels or sub-pixels in the display area unit, for example, and may be hereinafter referred to as light transmittance / first specified value.
Lt ₂ ... In the display area unit / input signal maximum value x _U-max that is the maximum value of the values of the input signals input to the drive circuit for driving all the pixels constituting the display area unit. This is the light transmittance (aperture ratio) of the pixel or sub-pixel when it is assumed that a control signal corresponding to an input signal having the same value is supplied to the pixel or sub-pixel. Sometimes called. In addition, 0 ≦ Lt ₂ ≦ Lt ₁
y ₂ ... When the light source luminance is the light source luminance and the first specified value Y ₁ and the light transmittance (aperture ratio) of the pixel or sub-pixel is assumed to be the light transmittance and the second specified value Lt ₂ The display brightness obtained in the following is sometimes referred to as “display brightness / second prescribed value”.
Y ₂ ... ・ In the display area unit ・ Assuming that a control signal corresponding to an input signal having a value equal to the input signal maximum value x _U-max is supplied to the pixel or sub-pixel, Assuming that the light transmittance (aperture ratio) of the sub-pixel is corrected to the light transmittance / first prescribed value Lt ₁ , the luminance of the pixel or the sub-pixel is set to the display luminance / second prescribed value (y ₂ ). The light source brightness of the planar light source unit. However, the light source luminance Y ₂ may be corrected in consideration of the influence of the light source luminance of each planar light source unit on the light source luminance of other planar light source units.

When the planar light source device is partially driven, it is assumed that a control signal corresponding to an input signal having a value equal to the input signal maximum value x _U-max in the display area unit is supplied to the pixel. The luminance of the light source constituting the planar light source unit corresponding to the display area unit is controlled by the drive circuit so that the ratio, the display luminance at the first specified value Lt _1, and the second specified value y ₂ ) are obtained. Specifically, for example, the light source luminance Y ₂ is set so that the display luminance y ₂ can be obtained when the light transmittance (aperture ratio) of the pixel or sub-pixel is, for example, the light transmittance · the first specified value Lt _1. What is necessary is just to control (for example, to reduce). That is, for example, the light source luminance Y ₂ of the planar light source unit may be controlled for each image display frame so as to satisfy the following expression (1). Note that Y ₂ ≦ Y ₁ .

Y ₂ · Lt ₁ = Y ₁ · Lt ₂ (1)

When expressed in pixels arranged in a two-dimensional matrix the number M ₀ × N ₀ of _{(pixels) (M 0, N 0)} , the value of (M _0, N _0), specifically, VGA ( 640,480), S-VGA (800,600), XGA (1024,768), APRC (1152,900), S-XGA (1280,1024), U-XGA (1600,1200), HD-TV ( 1920, 1080), Q-XGA (2048, 1536), (1920, 1035), (720, 480), (1280, 960), etc. It is not limited to these values. Further, the relationship between the value of (M ₀ , N ₀ ) and the value of (P, Q) is not limited, but can be exemplified in Table 1 below. Examples of the number of pixels constituting one display area unit include 20 × 20 to 320 × 240, preferably 50 × 50 to 200 × 200. The number of pixels in the display area unit may be constant or different.

  The driving circuit for driving the liquid crystal display device and the planar light source device includes, for example, a planar light source device control circuit and a planar light source configured by a light emitting diode (LED) driving circuit, an arithmetic circuit, a storage device (memory), etc. A unit drive circuit and a liquid crystal display device drive circuit including a known circuit such as a timing controller are provided. The luminance of the display area (display luminance) and the luminance of the planar light source unit (light source luminance) are controlled for each image display frame. Note that the number of image information (images per second) sent to the drive circuit as electrical signals per second is the frame frequency (frame rate), and the inverse of the frame frequency is the frame time (unit: seconds).

  In the planar light source device of the present invention, the liquid crystal display device assembly according to the first, third, and fourth embodiments of the present invention, the optical function sheet is disposed in front of the light diffusing plate, and the housing It is attached to the upper part of this front part in the state suspended from the upper part of the front part. Therefore, the optical function sheet is held so as to freely expand and contract with respect to the light diffusing plate, and when the optical function sheet is expanded by thermal expansion, wrinkles are not generated in the optical function sheet.

  Moreover, in the planar light source device of the present invention and the first aspect of the present invention, the linear member is disposed in front of the optical function sheet, and ends are attached to both sides of the front portion of the housing. ing. Therefore, even when the optical function sheet is stretched due to thermal expansion due to heat generated by the light source, the linear member prevents the optical function sheet from coming into contact with the liquid crystal display device, and the brightness of the display screen becomes non-uniform. The occurrence of this problem can be reliably prevented. In addition, since the linear member is arranged, the gap existing between the optical function sheet and the liquid crystal display device can be made as narrow as possible, so that a structure in which the parallax problem hardly occurs can be obtained.

  In the liquid crystal display device assembly according to the second aspect of the present invention, since the distance between the liquid crystal display device and the optical function sheet is controlled by the operation of the optical function sheet mounting means, the optical function sheet is heated by the heat generated by the light source. Even when the functional sheet is stretched due to thermal expansion, the optical functional sheet can be prevented from coming into contact with the liquid crystal display device, and the occurrence of the problem that the brightness of the display screen becomes uneven can be reliably prevented. In addition, since the gap existing between the optical function sheet and the liquid crystal display device can be made as narrow as possible, it is possible to obtain a structure in which the parallax problem hardly occurs.

  In the liquid crystal display device assembly according to the third aspect or the fourth aspect of the present invention, a light diffusion sheet is disposed on the surface of the liquid crystal display device facing the planar light source device, or the surface The polarizing plate constituting the surface of the liquid crystal display device opposed to the light source device has a light diffusion function. Therefore, a state in which an apparent light source is arranged in contact with the liquid crystal display device can be obtained, and as a result, a structure in which a parallax problem hardly occurs can be obtained.

Furthermore, in the present invention, a partial drive method (divided drive method) is adopted, and a control signal corresponding to an input signal having a value equal to the maximum value x _U-max in the display area unit is supplied to the pixel. In order to obtain the assumed pixel brightness (light transmittance, display brightness at the first specified value Lt ₁ , second specified value y ₂ ), the light source constituting the planar light source unit corresponding to the display area unit is obtained. If the luminance is controlled by the drive circuit, not only can the power consumption of the planar light source device be reduced, but also the white level can be increased and the black level can be reduced, and a high contrast ratio (on the screen surface of the liquid crystal display device, The brightness ratio of the all-black display part and all-white display part without external light reflection etc. can be obtained and the brightness of the desired display area can be emphasized, so that the image display quality is improved. Can be Kill.

  Hereinafter, the present invention will be described based on examples with reference to the drawings.

  Example 1 relates to the planar light source device of the present invention and the liquid crystal display device assembly according to the first aspect of the present invention. FIG. 1 shows a schematic view of the surface light source device of Example 1 as viewed from the front (liquid crystal display device side), and FIG. 2 shows a schematic partial cross-sectional view along the arrow AA in FIG.

The liquid crystal display device assembly of the first embodiment, or the liquid crystal display device assemblies of the second, fourth, and fifth embodiments, which will be described later, include the transmissive color liquid crystal display device 10 and the planar light source device 20. I have. The planar light source device 20
(A) housing 30,
(B) a light source 22 disposed inside the housing 30;
(C) a light diffusing plate 50 that is fixed to the front surface of the housing 30 and diffuses / transmits light emitted from the light source 22; and
(D) An optical element that is disposed in front of the light diffusion plate 50 and is attached to the upper portion 32 of the front surface portion while being suspended from the upper portion of the front surface portion of the housing 30 and allows light emitted from the light diffusion plate to pass therethrough. Function sheet 51,
It has.

And in the planar light source device 20 of Example 1, further,
(E) a linear member 40 disposed in front of the optical function sheet 51 and having ends attached to both side portions 34 and 35 of the front surface portion of the housing 30;
It has.

  Details of the transmissive color liquid crystal display device 10 will be described in a second embodiment.

  In the first embodiment, the linear members (wires) 40 extend in the horizontal direction, and the number of the linear members 40 may be at least one, and in the first embodiment, the number is two. The linear member 40 is made of a stainless steel wire, and has a thickness (diameter) such that a shadow of the linear member 40 is not recognized by an observer who views the image of the color liquid crystal display device 10, specifically 20 μm. . Both ends of the linear member 40 are wound around a mounting portion 41 made up of pins attached to both side portions 34 and 35 of the front surface portion of the housing 30, welded, and fixed. In the state where the optical function sheet 51 hangs vertically, a gap SP is provided between the optical function sheet 51 and the linear member 40, although it is a little.

  In the first embodiment, the light source 22 includes a plurality of cold-cathode ray type fluorescent lamps and is attached in the horizontal direction inside the housing 30. The plurality of light sources 22 are simultaneously driven under the same driving conditions and under certain driving conditions.

  The housing 30 is made of metal (specifically, an electrogalvanized steel sheet), and has a box shape (cuboid shape) having a kind of opening as a whole and having four side surfaces and one bottom surface. It is a member. The opening faces the color liquid crystal display device 10, the peripheral edge of the opening corresponds to the front surface of the housing 30, and the four side surfaces are the upper portion 32, the lower portion 33, and the two sides of the housing 30. Corresponding to parts 34 and 35. In the following description, the upper portion 32, the lower portion 33, and the two side portions 34 and 35 of the housing 30 may be expressed as the housing upper portion 32, the housing lower portion 33, and the housing side portions 34 and 35, respectively. . The casing base 31 corresponding to the bottom surface is provided with a reflection sheet 55, and the light source 22 is mounted above the reflection sheet 55 via a mounting member (not shown). Here, the reflection sheet 55 is disposed so that the reflection surface thereof faces the light diffusion plate 50, and is attached to the base portion 31 of the housing 30 via an attachment member (not shown). The reflection sheet 55 can be composed of, for example, a silver-enhanced reflection film having a structure in which a silver reflection film, a low refractive index film, and a high refractive index film are sequentially laminated on a sheet base material. The reflection sheet 55 is reflected by the light emitted from the plurality of light sources 22, the housing upper part 32, the housing lower part 33, the housing side parts 34 and 35, or in the second embodiment to be described later, further by the partition wall 25. Reflects light.

  The light diffusing plate 50 made of a polycarbonate (PC) resin plate having a thickness of 2 mm is sandwiched between the inner frame 36A attached to the upper portion 32 of the casing and the upper portion 32 of the casing via the spacer 36B. It is fixed to the front surface of the housing 30. The end of the transmissive color liquid crystal display device 10 is held by a support panel 37 attached to the upper part 32 of the casing and the upper part 32 of the casing so as to be sandwiched between the spacers 36C and 36D.

  Specifically, the optical function sheet 51 has a configuration in which a light diffusion sheet 52, a prism sheet 53, and a polarization conversion sheet 54 are stacked. And the pin 38 is attached to the housing | casing upper part 32, and the hole is provided in the optical function sheet | seat 51, By engaging the pin 38 and a hole, the optical function sheet | seat 51 is attached to the housing | casing upper part 32. FIG. It shall be in the state suspended from. Accordingly, no pressure is applied in the thickness direction of the optical function sheet 51, and the optical function sheet 51 can freely move in the vertical and horizontal directions. The illumination light from the light source 22 is emitted through the light diffusion plate 50, passes through the optical function sheet 51 such as the light diffusion sheet 52, the prism sheet 53, and the polarization conversion sheet 54, and passes through the color liquid crystal display device 10 from the rear. Illuminate.

  In the first embodiment, the optical function sheet 51 is disposed in front of the light diffusing plate 50 and attached to the housing upper part 32 in a state of being hung from the housing upper part 32. Therefore, the optical function sheet 51 is held so as to freely expand and contract with respect to the light diffusing plate 50. When the optical function sheet 51 is expanded by thermal expansion, the optical function sheet 51 is not wrinkled. Moreover, the linear member 40 is disposed in front of the optical function sheet 51, and ends are attached to the housing side portions 34 and 35. Therefore, even when the optical function sheet 51 is stretched due to thermal expansion, the linear member 40 prevents the optical function sheet 51 from coming into contact with the liquid crystal display device 10, and the brightness of the display screen becomes uneven. The occurrence of problems can be reliably prevented. In addition, since the linear member 40 is disposed, the gap SP existing between the optical function sheet 51 and the liquid crystal display device 10 is about 0.6 when the linear member 40 is not disposed. I was able to narrow it. As a result, the entire thickness of the liquid crystal display device assembly could be reduced. Further, conventionally, the thickness of the optical function sheet 51 is increased so that the optical function sheet 51 does not come into contact with the liquid crystal display device 10. However, in the first embodiment, the optical function sheet 51 is used. Is not in contact with the liquid crystal display device 10, the thickness of the optical function sheet 51 can be reduced.

  The second embodiment is a modification of the first embodiment. In Example 2, the light source was composed of a light emitting element, specifically, a light emitting diode. FIG. 3 shows a schematic partial cross-sectional view of the liquid crystal display device assembly of Example 2. This partial cross-sectional view is the same partial cross-sectional view as taken along the arrow AA in FIG. Moreover, the schematic diagram which looked at the planar light source device of Example 2 from the front (liquid crystal display device side) is the same as FIG. FIG. 4 shows a schematic view of the surface light source device of Example 2 as viewed from the front (liquid crystal display device side) with the optical function sheet 51 and the light diffusion plate 50 removed. In addition, a color liquid crystal display device and a planar light source suitable for use in Embodiment 2 or Embodiments 3 to 5 described later (hereinafter, these may be collectively referred to as Embodiment 2). FIG. 5 shows a conceptual diagram of a liquid crystal display device assembly composed of the device, FIG. 6 shows a conceptual diagram of a part of a drive circuit suitable for use in Example 2 and the like, and a schematic part of a color liquid crystal display device. A cross-sectional view is shown in FIG.

The liquid crystal display device assembly of Example 2 etc.
(A) a transmissive color liquid crystal display device 10 having a display area 11 composed of pixels arranged in a two-dimensional matrix, and
(B) The number of display areas 11 of the color liquid crystal display device 10 is P in the first direction and Q in the second direction extending at right angles to the first direction, for a total of P × Q virtual display areas. The color liquid crystal display device 10 corresponds to the P × Q display area units 12 when assumed to be divided into units 12, each of which includes P × Q planar light source units 21 each having a light source 23. A planar light source device 20 for illuminating from the rear,
It has.

  That is, the planar light source device 20 according to the second embodiment is a planar light source device that illuminates the transmissive color liquid crystal display device 10 having the display region 11 composed of pixels arranged in a two-dimensional matrix from the rear. Then, P display areas 11 of the liquid crystal display device 10 are P in the first direction and Q in the second direction extending perpendicular to the first direction, for a total of P × Q virtual display area units 12. The display area units 12 correspond to the P × Q display area units 12 when it is assumed that the display area units 12 are divided into the P × Q planar light source units 21 each having a light source 23. In the planar light source device 20 or the liquid crystal display assembly of the second embodiment, the light emission state of the light source 23 provided in the planar light source unit 21 is individually controlled. That is, a partial drive method or a split drive method is adopted.

  It should be noted that the planar light source device 20 is composed of a planar light source unit 21 and the light source 23 is composed of a light emitting element, specifically, a light emitting diode 23R, 23G, 23B. Since the configuration and structure of the light source device can be substantially the same as the configuration and structure of the liquid crystal display device assembly and the planar light source device described in the first embodiment, the differences from the first embodiment will be described below. , Explain.

Specifically, as shown in a conceptual diagram in FIG. 5, the transmissive color liquid crystal display device 10 in the second embodiment or the like has M ₀ pieces along the first direction and N ₀ along the second direction. A total of M ₀ × N ₀ pixels are provided with a display region 11 arranged in a two-dimensional matrix. Here, in Example 2 or the like, it is assumed that the display area 11 is divided into P × Q virtual display area units 12. Each display area unit 12 is composed of a plurality of pixels. Specifically, for example, the image display resolution satisfies the HD-TV standard, and the number M ₀ × N ₀ of pixels (pixels) arranged in a two-dimensional matrix is expressed as (M ₀ , N ₀ ). For example, (1920, 1080). In addition, a display area 11 (indicated by a one-dot chain line in FIG. 5) composed of pixels arranged in a two-dimensional matrix is divided into P × Q virtual display area units 12 (the boundary is indicated by a dotted line). ing. The value of (P, Q) is (19, 12), for example. However, in order to simplify the drawings, the numbers of the display area units 12 and the planar light source units 21 in FIGS. 4 and 5 are different from these values. Each display area unit 12 is composed of a plurality of (M × N) pixels, and the number of pixels constituting one display area unit 12 is, for example, about 10,000. Each pixel is configured as a set of a plurality of sub-pixels that emit different colors. More specifically, each pixel has three types of red light emitting subpixel (subpixel [R]), green light emitting subpixel (subpixel [G]), and blue light emitting subpixel (subpixel [B]). Of sub-pixels (sub-pixels). The transmissive color liquid crystal display device 10 is line-sequentially driven. More specifically, the color liquid crystal display device 10 includes scan electrodes (extending along the first direction) and data electrodes (extending along the second direction) that intersect in a matrix. Then, a scanning signal is input to the scanning electrode to select and scan the scanning electrode, and an image is displayed based on the data signal (a signal based on the control signal) input to the data electrode to constitute one screen.

  The liquid crystal display device according to the first embodiment also has the above-described configuration and structure, but is not partially driven. Therefore, it is assumed that the display area 11 is divided into P × Q virtual display area units 12. It is not necessary to introduce the concept of doing.

  The color liquid crystal display device 10 includes a front panel 60 provided with a transparent first electrode 64, a rear panel 70 provided with a transparent second electrode 74, and a schematic partial sectional view shown in FIG. The liquid crystal material is disposed between the front panel 60 and the rear panel 70.

  The front panel 60 includes, for example, a first substrate 61 made of a glass substrate and a polarizing plate (polarizing film / polarizing sheet) 66 provided on the outer surface of the first substrate 61. A color filter 62 covered with an overcoat layer 63 made of acrylic resin or epoxy resin is provided on the inner surface of the first substrate 61. On the overcoat layer 63, a transparent first electrode (also called a common electrode) is provided. (For example, made of ITO) 64 is formed, and an alignment film 65 is formed on the transparent first electrode 64. On the other hand, the rear panel 70 more specifically includes, for example, a second substrate 71 made of a glass substrate, and switching elements (specifically, thin film transistors and TFTs) formed on the inner surface of the second substrate 71. 72, a transparent second electrode (also referred to as a pixel electrode, made of, for example, ITO) 74 whose conduction / non-conduction is controlled by the switching element 72, and a polarizing plate (polarized light) provided on the outer surface of the second substrate 71 Film / polarizing sheet) 76. An alignment film 75 is formed on the entire surface including the transparent second electrode 74. The front panel 60 and the rear panel 70 are joined to each other at their outer peripheral portions via a sealing material (not shown). Note that the switching element 72 is not limited to a TFT, and may be composed of, for example, an MIM element. Reference numeral 77 in the drawing is an insulating layer provided between the switching element 72 and the switching element 72.

  Since various members and liquid crystal materials constituting these transmissive color liquid crystal display devices can be composed of well-known members and materials, detailed description thereof is omitted.

  The direct-type planar light source device (backlight) 20 includes P × Q planar light source units 21 corresponding to P × Q virtual display area units 12, and each planar light source unit 21 includes a planar light source unit 21. The display area unit 12 corresponding to the light source unit 21 is illuminated from behind with white light. The planar light source unit 21 is partitioned by a partition wall 25. The light sources 23 provided in the planar light source unit 21 are individually controlled. However, the light source luminance of the planar light source unit 21 is not affected by the light emission state of the light sources 23 provided in the other planar light source units 21. In addition, although the planar light source device 20 is located behind the color liquid crystal display device 10, the color liquid crystal display device 10 and the planar light source device 20 are displayed separately in FIG. The light source 23 includes light emitting diodes 23R, 23G, and 23B that are driven based on a pulse width modulation (PWM) control method. The luminance of the planar light source unit 21 is increased / decreased by increasing / decreasing the duty ratio in the pulse width modulation control of the light emitting diodes 23R, 23G, 23B constituting the planar light source unit 21. Thus, for example, red light emitted from a red light emitting diode 23R that emits red with a wavelength of 640 nm, for example, a green light emitting diode 23G that emits green with a wavelength of 530 nm, and a blue light emitting diode 23B that emits blue with a wavelength of 450 nm, for example. Light and blue light are mixed, and white light with high color purity can be obtained as illumination light. The white illumination light is emitted from the planar light source unit 21 through the light diffusion plate 50, passes through the optical function sheet 51 such as the light diffusion sheet 52, the prism sheet 53, and the polarization conversion sheet 54, and is a color liquid crystal display device. 10 is illuminated from behind. The light emitting diodes 23R, 23G, and 23B may be collectively indicated by the light source 23.

  In the vicinity of the casing base 31, photodiodes 24R, 24G, and 24B, which are optical sensors, are arranged. The photodiode 24R is a photodiode with a red filter attached to measure the light intensity of red light, and the photodiode 24G is a photo diode with a green filter attached to measure the light intensity of green light. The photodiode 24B is a photodiode to which a blue filter is attached in order to measure the light intensity of blue light. Here, one set of photosensors (photodiodes 24R, 24G, 24B) is arranged in one planar light source unit 21. In FIG. 4, the photodiodes 24R, 24G, and 24B are not shown.

  As shown in FIGS. 5 and 6, the driving circuit for driving the planar light source device 20 and the color liquid crystal display device 10 based on an input signal from the outside (display circuit) is based on the pulse width modulation control method. Planar light source device control circuit 80 and planar light source unit drive circuit 90 for performing on / off control of the red light emitting diode 23R, the green light emitting diode 23G, and the blue light emitting diode 23B constituting the planar light source device 20, and a liquid crystal display The apparatus driving circuit 85 is used.

  The planar light source device control circuit 80 includes an arithmetic circuit 81 and a storage device (memory) 82. On the other hand, the planar light source unit driving circuit 90 includes an arithmetic circuit 91, a storage device (memory) 92, an LED driving circuit 93, a photodiode control circuit 94, switching elements 95R, 95G, and 95B including FETs, and a light emitting diode driving power source (constant). Current source) 96. These circuits constituting the planar light source device control circuit 80 and the planar light source unit driving circuit 90 may be known circuits. On the other hand, a liquid crystal display device driving circuit 85 for driving the color liquid crystal display device 10 is configured by a known circuit such as a timing controller 86. The color liquid crystal display device 10 is provided with a gate driver, a source driver, and the like (not shown) for driving a switching element 72 composed of a TFT constituting a liquid crystal cell.

Downstream of the light emitting diodes 23R, 23G, 23B, current detection resistors r _R , r _G , r _B are inserted in series with the light emitting diodes 23R, 23G, 23B, and the resistors r _R , r _G , The operation of the light emitting diode drive power supply 96 is controlled under the control of the LED drive circuit 93 so that the current flowing through r _B is converted into a voltage, and the voltage drop in the resistors r _R , r _G , r _B becomes a predetermined value. Is done. Here, FIG. 6 shows one light emitting diode driving power source (constant current source) 96, but actually, the light emitting diode driving power source for driving each of the light emitting diodes 23R, 23G, and 23B. 96 is arranged.

  The light emitting states of the light emitting diodes 23R, 23G, and 23B in a certain image display frame are measured by the photodiodes 24R, 24G, and 24B, and outputs from the photodiodes 24R, 24G, and 24B are input to the photodiode control circuit 94. In the photodiode control circuit 94 and the arithmetic circuit 91, for example, data (signals) as the luminance and chromaticity of the light emitting diodes 23R, 23G, and 23B are transmitted to the LED driving circuit 93, and the next image display frame A feedback mechanism is formed in which the light emitting states of the light emitting diodes 23R, 23G, and 23B are controlled.

  A display area 11 composed of pixels arranged in a two-dimensional matrix is divided into P × Q display area units. When this state is expressed by “row” and “column”, Q rows × It can be said that the display area unit is divided into P columns. The display area unit 12 is composed of a plurality of (M × N) pixels. When this state is expressed by “row” and “column”, it is composed of pixels of N rows × M columns. I can say. Further, the red light emitting subpixel (subpixel [R]), the green light emitting subpixel (subpixel [G]), and the blue light emitting subpixel (subpixel [B]) are collectively collected as “subpixel [ R, G, B] ”and may be referred to as“ sub-pixel ”for controlling the operation of the sub-pixel [R, G, B] (specifically, for example, controlling the light transmittance (aperture ratio)). The red light emitting subpixel / control signal, the green light emitting subpixel / control signal, and the blue light emitting subpixel / control signal input to [R, G, B] are collectively referred to as “control signal [R, G, B] ”and may be referred to as a red light-emitting subpixel / input signal or a green light-emitting subpixel that is input to the drive circuit from the outside in order to drive the subpixels [R, G, B] constituting the display area unit. The input signal and the blue light emitting subpixel / input signal may be collectively referred to as “input signal [R, G, B]”.

As described above, each pixel includes a red light emitting subpixel (red light emitting subpixel, subpixel [R]), a green light emitting subpixel (green light emitting subpixel, subpixel [G]), and a blue light emitting subpixel ( The blue light emitting subpixel and the subpixel [B]) are configured as a set of three subpixels (subpixels). In the description of the following examples, the sub pixels [R, G, B] each control of the luminance of the (gradation control) and 8-bit control, and performed at 2 ⁸ steps of 0 to 255. Therefore, the value of the input signal [R, G, B] input to the liquid crystal display device drive circuit 85 to drive each of the sub-pixels [R, G, B] in each pixel constituting each display area unit 12. x _R, x _G, each x _B, takes a value of 2 ⁸ steps. Further, pulse width modulation output signal values S _R , S _G , S for controlling the respective light emission times of the red light emitting diode 23R, the green light emitting diode 23G, and the blue light emitting diode 23B constituting each planar light source unit. _B also takes a value of 2 ⁸ steps of 0 to 255. However, the present invention is not limited to this. For example, 10-bit control can be performed in 2 ¹⁰ stages from 0 to 1023. In this case, if an 8-bit numerical expression is multiplied by, for example, 4 times Good.

A control signal for controlling the light transmittance Lt of each sub-pixel is supplied from the drive circuit to each sub-pixel. Specifically, a control signal [R, G, B] for controlling the light transmittance Lt of each of the sub-pixels [R, G, B] is transmitted to each of the sub-pixels [R, G, B]. Supplied from the drive circuit 85. That is, in the liquid crystal display device driving circuit 85, the control signals [R, G, B] are generated from the input signals [R, G, B], and the control signals [R, G, B] are subpixels. [R, G, B] are supplied (output). Since the light source luminance Y ₂ which is the luminance of the planar light source unit 21 is changed for each image display frame, the control signal [R, G, B] is, for example, the value of the input signal [R, G, B]. Values X _R-corr , X _G-corr , and X _B-corr obtained by performing correction (compensation) based on changes in the light source luminance Y _{2 with} respect to the values obtained by raising x _R , x _G , and x _B to the power of 2.2 Have. Then, the control signal [R, G, B] is sent from the timing controller 86 constituting the liquid crystal display device driving circuit 85 to the gate driver and source driver of the color liquid crystal display device 10 by a known method. The switching elements 72 constituting each subpixel are driven based on [R, G, B], and a desired voltage is applied to the transparent first electrode 64 and the transparent second electrode 74 constituting the liquid crystal cell. The light transmittance (aperture ratio) Lt of the sub-pixel is controlled. Here, the larger the values X _R-corr , X _G-corr , and X _B-corr of the control signal [R, G, B], the light transmittance (aperture ratio) Lt of the sub-pixel [R, G, B]. And the value of the luminance (display luminance y) of the display area corresponding to the sub-pixel [R, G, B] increases. That is, an image composed of light passing through the sub-pixels [R, G, B] (usually a kind of dot) is bright.

The display brightness y and the light source brightness Y ₂ are controlled for each image display frame, each display area unit, and each planar light source unit in the image display of the color liquid crystal display device 10. The operation of the color liquid crystal display device 10 and the operation of the planar light source device 20 within one image display frame are synchronized. Note that the number of image information (images per second) sent to the drive circuit as electrical signals per second is the frame frequency (frame rate), and the inverse of the frame frequency is the frame time (unit: seconds).

  In Example 2, in addition to the effects described in Example 1, the occurrence of the parallax problem shown in FIG. 15B and FIG. 16 could be suppressed.

  Example 3 relates to a liquid crystal display device assembly according to a second aspect of the present invention. A schematic partial cross-sectional view of the liquid crystal display device assembly of Example 3 is shown in FIG. 8, which is a partial cross-sectional view similar to that taken along the arrow AA in FIG. Further, in the planar light source device of Example 3, the schematic view seen from the front (liquid crystal display device side) after removing the optical function sheet 51 and the light diffusing plate 50 does not include the pin 38 and the mounting portion 41. 4 is the same as FIG. Further, a conceptual diagram of a liquid crystal display device assembly composed of a color liquid crystal display device and a planar light source device suitable for use in Embodiment 3 or Embodiments 4 to 5 to be described later, for use in Embodiment 3. A conceptual diagram of a part of a suitable drive circuit and a schematic partial sectional view of a color liquid crystal display device are the same as those shown in FIGS. 5, 6, and 7, respectively.

  The liquid crystal display device assembly of the third embodiment is substantially different from the liquid crystal display device assembly described in the second embodiment only in the points described below, so only the differences will be described.

  That is, in the third embodiment, the optical function sheet 51 is disposed in front of the light diffusion plate 50 and allows the light emitted from the light diffusion plate 50 to pass therethrough. The liquid crystal display device 10 is suspended from an upper part of a support panel 37 provided via an optical function sheet attaching means 39. The distance between the liquid crystal display device 10 and the optical function sheet 51 is controlled by the operation of the optical function sheet attaching means 39.

  More specifically, the optical function sheet attaching means 39 is made of a bimetal plate. One end of the optical function sheet attaching means 39 is attached to the support panel 37 by, for example, screws (not shown). Further, the other end portion of the optical function sheet attaching means 39 is free, and a pin 38 ′ is attached to the other end portion of the optical function sheet attaching means 39. The optical function sheet 51 is provided with a hole. By engaging the pin 38 ′ with the hole, the optical function sheet 51 can be suspended from the upper part of the support panel 37 via the optical function sheet mounting means 39. State.

  During the operation of the liquid crystal display device assembly, the shape of the optical function sheet mounting means 39 changes as a result of the temperature of the bimetal plate being the optical function sheet mounting means 39 being raised by the heat generated by the light source 23. Specifically, the other end portion of the optical function sheet attaching means 39 warps away from the main body portion of the liquid crystal display device 10 (see the schematic partial sectional view of the liquid crystal display device assembly in FIG. 9). . As a result, the optical function sheet 51 is moved away from the liquid crystal display device 10. Thus, even when the optical function sheet 51 is stretched due to thermal expansion due to heat generated by the light source 23, the optical function sheet 51 can be prevented from coming into contact with the liquid crystal display device 10, and the display screen can be prevented. It is possible to reliably prevent the occurrence of the problem that the luminance of the light becomes uneven. Further, since the gap existing between the optical function sheet 51 and the liquid crystal display device 10 can be reduced as much as possible, a structure in which the parallax problem hardly occurs can be achieved.

  Example 4 relates to the liquid crystal display device assembly according to the third aspect of the present invention. The schematic partial cross-sectional view of the liquid crystal display device assembly of Example 4 is the same as that shown in FIG. 3, and this partial cross-sectional view is the same as the cross-sectional view taken along the arrow AA in FIG. It is. Further, in the planar light source device of Example 4, a schematic diagram viewed from the front (liquid crystal display device side) with the optical function sheet 51 and the light diffusion plate 50 removed is the same as FIG. That is, the liquid crystal display device assembly of the fourth embodiment is substantially an improvement of the liquid crystal display device assembly of the second embodiment, but the liquid crystal display has a configuration and structure excluding the linear member 40 and the mounting portion 41. It can also be a display device assembly.

  In the liquid crystal display device assembly of Example 4, a light diffusion sheet 13 is disposed on the surface of the liquid crystal display device 10 facing the planar light source device 20, as shown in a conceptual diagram in FIG. Yes. Specifically, the light diffusion sheet 13 is bonded onto the polarizing plate (polarizing film / polarizing sheet) 76 shown in FIG. 7 using an adhesive. Specifically, the light diffusion sheet 13 is configured by applying a mixture of an acrylic resin as a binder and PMMA particles as a light diffusion material to a PET base material and solidifying the binder.

  Thus, since the light diffusion sheet 13 is disposed on the surface of the liquid crystal display device 10 facing the planar light source device 20, it is as if the entire light diffusion sheet 13 in close contact with the liquid crystal display device 10 is used. As a result, the parallax problem hardly occurs.

  As shown in the conceptual diagram of FIG. 10B, the optical function sheet 51 is configured by superimposing the light diffusion sheet 52 and the prism sheet 53, and the polarization conversion sheet 54 is composed of the light diffusion sheet 13 and the polarizing plate 76. It can also be set as the structure pinched | interposed between.

  Example 5 relates to a liquid crystal display device assembly according to a fourth aspect of the present invention. A schematic partial cross-sectional view of the liquid crystal display device assembly of Example 5 is the same as that shown in FIG. 3, and this partial cross-sectional view is the same as the cross-sectional view taken along the arrow AA in FIG. It is. Further, in the planar light source device of Example 5, the schematic diagram viewed from the front (liquid crystal display device side) with the optical function sheet 51 and the light diffusion plate 50 removed is the same as FIG. That is, the liquid crystal display device assembly of the fifth embodiment is substantially an improvement of the liquid crystal display device assembly of the second embodiment, but the liquid crystal having the configuration and structure excluding the linear member 40 and the mounting portion 41. It can also be a display device assembly.

  In the liquid crystal display device assembly of Example 5, as shown in a conceptual diagram in FIG. 11, a polarizing plate (polarizing film / polarizing sheet) constituting the surface of the liquid crystal display device 10 facing the planar light source device 20. 76 'has a light-diffusion function. Specifically, a light diffusing material is fixed to the outer surface of the polarizing plate 76 '. The light diffusing material is made of, for example, PMMA particles. For example, a mixture of a binder made of an acrylic resin and a light diffusing material is applied onto the polarizing plate 76 ′, and the binder is solidified, whereby the light diffusing material is applied to the polarizing plate 76 ′. It can be fixed.

  Thus, since the polarizing plate 76 ′ constituting the surface of the liquid crystal display device 10 facing the planar light source device 20 has a light diffusion function, it is as if the entire light diffusion sheet in close contact with the liquid crystal display device 10 is used. As a result of appearing to illuminate the liquid crystal display device 10, a parallax problem hardly occurs.

  Hereinafter, the driving method of the liquid crystal display device assembly in Examples 2 to 5 will be described with reference to FIGS. 5, 6, and 12. FIG. 12 is a flowchart for explaining a method of driving the liquid crystal display device assembly according to the second to fifth embodiments.

In the second to fifth embodiments, a control signal for controlling the light transmittance Lt of each sub-pixel is supplied from the drive circuit to each sub-pixel. More specifically, a control signal [R, G, B] that controls the light transmittance Lt of each of the sub-pixels [R, G, B] is supplied to each of the sub-pixels [R, G, B] constituting each pixel. B] is supplied from the drive circuit 90. In each of the planar light source units 21, inputs that are input to the drive circuits 80, 90, and 85 to drive all the pixels (subpixels [R, G, B]) constituting each display area unit 12. A control signal corresponding to an input signal having a value equal to the maximum value x _U-max in the display area unit that is the maximum value x _R , x _G , x _B of the signals [R, G, B]. Of the pixel (sub-pixel [R, G, B]) (light transmittance, display luminance at the first specified value Lt ₁ , second specified value y ₂ ) is obtained. As described above, the luminance of the light source 23 constituting the planar light source unit 21 corresponding to the display area unit 12 is controlled by the planar light source device control circuit 80 and the planar light source unit driving circuit 90. Specifically, for example, the light source luminance Y ₂ is obtained so that the display luminance y ₂ can be obtained when the light transmittance (aperture ratio) of the pixel or the sub-pixel is, for example, the light transmittance · the first specified value Lt _1. May be controlled (for example, decreased). That is, for example, the light source luminance Y ₂ of the planar light source unit 21 may be controlled for each image display frame so as to satisfy the following expression (1). Note that Y ₂ ≦ Y ₁ .

Y ₂ · Lt ₁ = Y ₁ · Lt ₂ (1)

[Step-100]
An input signal [R, G, B] and a clock signal CLK for one image display frame sent from a known display circuit such as a scan converter are input to the planar light source device control circuit 80 and the liquid crystal display device drive circuit 85. (See FIG. 5). Note that the input signals [R, G, B] are output signals from the image pickup tube, for example, when the input light quantity to the image pickup tube is y ′, and are output from, for example, a broadcasting station and the light transmittance of the sub-pixels. This is an input signal that is also input to the liquid crystal display drive circuit 85 to control Lt, and can be expressed as a function of the input light amount y ′ to the 0.45th power. The values x _R , x _G , x _B of the input signals [R, G, B] for one image display frame input to the surface light source device control circuit 80 constitute the surface light source device control circuit 80. The data is temporarily stored in the storage device (memory) 82. Further, the values x _R , x _G , x _B of the input signals [R, G, B] for one image display frame inputted to the liquid crystal display device driving circuit 85 are also stored in the liquid crystal display device driving circuit 85. (Not shown) once stored.

[Step-110]
Next, in the arithmetic circuit 81 constituting the surface light source device control circuit 80, the value of the input signal [R, G, B] stored in the storage device 82 is read, and the (p, q) th [however, first , P = 1, q = 1] for driving the sub-pixels [R, G, B] in all the pixels constituting the (p, q) -th display region unit 12 In the display circuit unit, the input signal maximum value x _U-max , which is the maximum value among the values x _R , x _G , x _B of the input signals [R, G, B], is obtained by the arithmetic circuit 81. Then, the display area unit / input signal maximum value x _U-max is stored in the storage device 82. This step is executed for all of m = 1, 2,..., M, n = 1, 2,..., N, that is, for M × N pixels.

For example, when x _R is a value corresponding to “110”, x _G is a value corresponding to “150”, and x _B is a value corresponding to “50”, x _U-max is “150”. Is a value corresponding to.

This operation is repeated from (p, q) = (1, 1) to (P, Q), and the display area unit internal input signal maximum value x _U-max in all the display area units 12 is stored in the storage device 82. Remember.

[Step-120]
Then, the control signal [R, G, B] corresponding to the input signal [R, G, B] having a value equal to the maximum value x _U-max in the display area unit is sub-pixel [R, G, B]. ] Corresponding to the display area unit 12 so that the brightness (light transmittance, display brightness at the first specified value Lt ₁ , second specified value y ₂ ) is obtained by the planar light source unit 21. The luminance (light source luminance Y ₂ ) of the light source 23 constituting the planar light source unit 21 is increased or decreased under the control of the planar light source unit drive circuit 90. Specifically, the light source luminance Y ₂ may be controlled for each image display frame and for each planar light source unit so as to satisfy the following expression (1). More specifically, the luminance of the light source 23 (light emitting diodes 23R, 23G, and 23B) is controlled based on the equation (2) that is the light source luminance control function g (x _nol-max ), and the equation (1) is satisfied. The light source luminance Y ₂ may be controlled as described above. A conceptual diagram of such control is shown in FIGS. 14 (A) and 14 (B). However, as will be described later, correction based on the influence of the other planar light source unit 21 is performed on the light source luminance Y ₂ as necessary. It should be noted that these relations regarding the control of the light source luminance Y ₂ , that is, the value of the control signal corresponding to the input signal having a value equal to the maximum value x _U-max in the display area unit and the input signal maximum value x _U-max . , The display luminance when assuming that such a control signal is supplied to the pixel (sub-pixel), the second specified value y ₂ , the light transmittance (aperture ratio) of each sub-pixel at this time [light transmittance / first 2 specified value Lt ₂ ], and a planar light source that provides display luminance and second specified value y ₂ when the light transmittance (aperture ratio) of each sub-pixel is set to light transmittance and first specified value Lt _1. The relationship of the brightness control parameters in the unit 21 may be obtained in advance and stored in the storage device 82 or the like.

Y ₂ · Lt ₁ = Y ₁ · Lt ₂ (1)
g (x _nol-max ) = a ₁ · (x _nol-max ) ^2.2 + a ₀ (2)

Here, input signals (input signals [R, G, B]) that are input to the liquid crystal display driving circuit 85 to drive the pixels (or the sub-pixels [R, G, B] constituting the pixels). ) _Is the maximum value x _max
x _nol-max ≡ x _U-max / x _max
And a ₁ and a ₀ are constants,
a ₁ + a ₀ = 1
0 <a ₀ <1, 0 <a ₁ <1
Can be expressed as For example,
a ₁ = 0.99
a ₀ = 0.01
And it is sufficient. The value x _R, x _G of the input signal [R, G, B], each x _B, and takes a value of 2 ⁸ steps, the value of x _max is a value corresponding to "255".

  By the way, in the planar light source device 20, for example, assuming brightness control of the planar light source unit 21 of (p, q) = (1, 1), other P × Q planar light source units. It may be necessary to consider the effects from 21. Since the influence that the planar light source unit 21 receives from the other planar light source units 21 is known in advance by the light emission profile of each planar light source unit 21, the difference can be calculated by back calculation, and as a result, the correction is performed. Is possible. The basic form of calculation will be described below.

The luminance (light source luminance Y ₂ ) required for the P × Q planar light source units 21 based on the requirements of the equations (1) and (2) is represented by a matrix [L _PxQ ]. Further, the luminance of a certain planar light source unit obtained when only a certain planar light source unit is driven and the other planar light source units are not driven is compared with P × Q planar light source units 21. Obtain in advance. Such luminance is represented by a matrix [L ′ _PxQ ]. Further, the correction coefficient is represented by a matrix [α _PxQ ]. Then, the relationship between these matrices can be expressed by the following equation (3-1). The correction coefficient matrix [α _PxQ ] can be obtained in advance.
[L _PxQ ] = [L ′ _PxQ ] · [α _PxQ ] (3-1)
Therefore, what is necessary is just to obtain | _require matrix [L' _PxQ ] from Formula (3-1). The matrix [L ′ _PxQ ] can be obtained from the inverse matrix operation. That is,
[L ′ _PxQ ] = [L _PxQ ] · [α _PxQ ] ⁻¹ (3-2)
Should be calculated. Then, the light sources 23 (light emitting diodes 23R, 23G, and 23B) provided in each planar light source unit 21 may be controlled so that the luminance represented by the matrix [L ′ _PxQ ] is obtained. Such operations and processes may be performed using information (data table) stored in the storage device (memory) 82. In the control of the light emitting diodes 23R, 23G, and 23B, since the value of the matrix [L ′ _PxQ ] cannot take a negative value, it is needless to say that the calculation result needs to be kept in a positive region. . Therefore, the solution of equation (3-2) may not be an exact solution but an approximate solution.

As described above, the matrix [L _PxQ ] obtained based on the values of the equations (1) and (2) obtained in the arithmetic circuit 81 constituting the surface light source device control circuit 80, and the matrix [α _PxQ ] of the correction coefficient. ], As described above, the luminance matrix [L ′ _PxQ ] when it is assumed that the planar light source unit is driven alone is obtained, and further, 0 to 0 based on the conversion table stored in the storage device 82. Convert to a corresponding integer (value of the pulse width modulation output signal) in the range of 255. Thus, the arithmetic circuit 81 constituting the planar light source device control circuit 80, the value S _R of the pulse width modulation output signal for controlling the light emission time of the red light emitting diode 23R in the surface light source unit 21, the green light emitting diode 23G The value S _G of the pulse width modulation output signal for controlling the light emission time and the value S _B of the pulse width modulation output signal for controlling the light emission time of the blue light emitting diode 23B can be obtained.

[Step-130]
Next, the values S _R , S _G , S _B of the pulse width modulation output signal obtained in the arithmetic circuit 81 constituting the surface light source device control circuit 80 are the surfaces provided corresponding to the surface light source unit 21. To the storage device 92 of the light source unit driving circuit 90 and stored in the storage device 92. The clock signal CLK is also sent to the planar light source unit driving circuit 90 (see FIG. 6).

[Step-140]
Then, based on the values S _R , S _G and S _B of the pulse width modulation output signal, the on time t _R-ON and the off time t _{R-OFF of} the red light emitting diode 23R constituting the planar light source unit 21, the green light emitting diode The arithmetic circuit 91 determines the ON time t _G-ON and OFF time t _{G-OFF of} 23G and the ON time t _B-ON and OFF time t _B-OFF of the blue light emitting diode 23B. still,
t _R-ON + t _R-OFF = t _G-ON + t _G-OFF = t _B-ON + t _B-OFF = constant value t _Const
It is. The duty ratio in driving based on pulse width modulation of the light emitting diode is
t _ON / (t _ON + t _OFF ) = t _ON / t _Const
Can be expressed as

The signals corresponding to the _ON times t _R-ON , t _G-ON , t _B-ON of the red light emitting diode 23R, the green light emitting diode 23G, and the blue light emitting diode 23B constituting the planar light source unit 21 are LED driving circuits. sent to 93, from the LED drive circuit 93, the on-time _{t R-oN, t G-} oN, based on the value of the signal corresponding to t _B-oN, the switching element 95R, 95G, 95B is, on-time t _R Only _-ON , _{tG -ON} , and _{tB -ON} are turned on, and the LED driving current from the light emitting diode driving power supply 96 is supplied to each of the light emitting diodes 23R, 23G, and 23B. As a result, each of the light emitting diodes 23R, 23G, and 23B emits light for the on times t _R-ON , t _G-ON , and t _B-ON in one image display frame. Thus, each display area unit 12 is illuminated at a predetermined illuminance.

The states obtained in this way are indicated by solid lines in FIGS. 13A and 13B. FIG. 13A shows an input signal input to the liquid crystal display device driving circuit 85 to drive the sub-pixels. value 2.2 squared value (x'≡x ^2.2) and is a diagram schematically showing the relationship between the duty ratio _{(= t ON / t Const)} , (B) in FIG. 13, the sub-pixel It is a figure which shows typically the relationship between the value X of the control signal for controlling the light transmittance Lt, and the display brightness | luminance y.

[Step-150]
On the other hand, the values x _R , x _G , x _B of the input signals [R, G, B] input to the liquid crystal display device driving circuit 85 are sent to the timing controller 86, and are input to the timing controller 86. A control signal [R, G, B] corresponding to the input signal [R, G, B] is supplied (output) to the sub-pixel [R, G, B]. The values X _R and X _{G of the} control signal [R, G, B] generated by the timing controller 86 of the liquid crystal display device driving circuit 85 and supplied from the liquid crystal display device driving circuit 85 to the sub-pixels [R, G, B]. , X _B and the values x _R , x _G , x _{B of} the input signals [R, G, B] are expressed by the following equations (4-1), (4-2), and (4-3): There is a relationship. However, _{b1_R} , _{b0_R} , _{b1_G} , _{b0_G} , _{b1_B} , _{b0_B} are constants. Further, since the light source luminance Y ₂ of the planar light source unit 21 is changed for each image display frame, the control signal [R, G, B] basically sets the value of the input signal [R, G, B] to 2. A value obtained by performing correction (compensation) based on a change in the light source luminance Y _{2 with} respect to the squared value. That is, in Examples 2 to 5, since the light source luminance Y ₂ is changed for each image display frame, the light source luminance Y ₂ (≦ Y ₁₎ Display brightness · second specified value y ₂ at the obtained As described above, the values X _R , X _G , and X _B of the control signal [R, G, B] are determined and corrected (compensated) to control the light transmittance (aperture ratio) Lt of the pixel or sub-pixel. . Here, the functions f _R , f _G , and f _B in the equations (4-1), (4-2), and (4-3) are functions obtained in advance for performing such correction (compensation). is there.

X _R = f _R (b 1 _—R · x _R ^2.2 + b 0 _—R ) (4-1)
X _G = f _G (b 1 _—G · x _G ^2.2 + b 0 _—G ) (4-2)
X _B = f _B (b 1 _—B · x _B ^2.2 + b 0 _—B ) (4-3)

  Thus, the image display operation in one image display frame is completed.

  As mentioned above, although this invention was demonstrated based on the preferable Example, this invention is not limited to these Examples. The configurations and structures of the transmissive color liquid crystal display device, the planar light source device, the planar light source unit, the liquid crystal display device assembly, and the drive circuit described in the embodiments are examples, and members, materials, and the like constituting these are also examples. This is an example, and can be changed as appropriate. Luminance compensation (correction) and temperature control of the planar light source unit may be performed by monitoring the temperature of the light emitting diode with a temperature sensor and feeding back the result to the planar light source unit drive circuit. In the embodiments, the description has been made on the assumption that the display area of the liquid crystal display device is divided into P × Q virtual display area units. However, in some cases, the transmissive liquid crystal display device has P × Q. You may have the structure divided | segmented into the actual display area unit. In the third to fifth embodiments, the light source may be composed of, for example, a plurality of cold cathode fluorescent lamps instead of the light emitting diodes 23R, 23G, and 23B.

  The first or second embodiment further includes a second linear member that is disposed in front of the optical function sheet 51 and has end portions attached to the upper portion 32 and the lower portion of the front surface portion of the housing 30. May be. Here, it is preferable that the second linear member extends in the vertical direction. The number of second linear members may be at least one and may be two or more. In some cases, the linear member may be omitted and only the second linear member may be provided. In the embodiment, the optical function sheet 51 is attached to the upper portion 32 of the front surface portion while being suspended from the upper portion 32 of the housing. However, the optical function sheet 51 is further movable. (In other words, pressure is not applied in the thickness direction of the optical function sheet 51), it may be attached to the lower portion 33 of the case, or may be attached to the side portions 34, 35 of the case so as to be movable. However, it may be movably attached to the case side parts 34 and 35 and the case lower part 33.

  In Example 3, the distance between the liquid crystal display device 10 and the optical function sheet 51 was controlled by the operation of the optical function sheet mounting means 39, but instead, it was disposed in the vicinity of the optical function sheet 51. The ambient temperature is measured by the temperature measuring means, and when the temperature exceeds a certain temperature, the optical function sheet 51 is moved by an actuator such as a motor or the optical function sheet 51 and the planar light source device 20 are moved. Thus, the distance between the liquid crystal display device 10 and the optical function sheet 51 may be controlled.

FIG. 1 is a schematic view of the planar light source device of Example 1 as viewed from the front (liquid crystal display device side). FIG. 2 is a schematic partial cross-sectional view of the liquid crystal display device assembly of Example 1 taken along the arrow AA of FIG. 3 is a schematic partial cross-sectional view of the liquid crystal display device assembly of Example 2 similar to that taken along the line AA in FIG. FIG. 4 is a schematic view of the planar light source device of Example 2 as viewed from the front (liquid crystal display device side), and shows a state where the optical function sheet and the light diffusion plate are removed. FIG. 5 is a conceptual diagram of a liquid crystal display device assembly including a color liquid crystal display device and a planar light source device suitable for use in the embodiment. FIG. 6 is a conceptual diagram of a portion of a drive circuit suitable for use in the embodiment. FIG. 7 is a schematic partial cross-sectional view of a color liquid crystal display device. FIG. 8 is a schematic partial cross-sectional view of the liquid crystal display device assembly of Example 3 similar to that taken along the line AA in FIG. 9 is a schematic partial cross-sectional view (although the light source is in an operating state) similar to that taken along the line AA in FIG. 1 of the liquid crystal display device assembly of Example 3. FIG. 10A and 10B are conceptual diagrams of the liquid crystal display device assembly of Example 4. FIG. FIG. 11 is a conceptual diagram of a liquid crystal display device assembly of Example 5. FIG. 12 is a flowchart for explaining a method of driving the liquid crystal display device assembly according to the second to fifth embodiments. FIG. 13A shows a value (x′≡x ^2.2 ) obtained by multiplying the value of an input signal input to the liquid crystal display device driving circuit to drive the subpixel by the power of 2.2 (x′≡x ^2.2 ) and the duty ratio (= t _ON / t _Const) and a diagram schematically showing the relationship, (B) in FIG. 13, the relationship between the value X of a control signal for controlling the light transmittance of the subpixel and the display luminance y schematically FIG. (A) and (B) of FIG. 14 show the display luminance when assuming that a control signal corresponding to an input signal having a value equal to the input signal maximum value x _U-max is supplied to the pixel. as second predetermined value y ₂ is obtained by the planar light source unit, the light source luminance Y ₂ of the planar light source unit is the conceptual view for describing under the control of the planar light source unit drive circuit, a state of increasing or decreasing . FIGS. 15A and 15B are a schematic view of a conventional planar light source device viewed from the front (liquid crystal display device side), and a problem in the conventional liquid crystal display device assembly, respectively. It is a conceptual diagram of the liquid crystal display device assembly. FIG. 16 is a simulation result showing that a difference in luminance occurs when an image displayed on the liquid crystal display device is viewed from the front and when viewed from an oblique direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Color liquid crystal display device, 11 ... Display area, 12 ... Display area unit, 20 ... Planar light source device, 21 ... Planar light source unit, 22 ... Light source, 23, 23R, 23G, 23B ... light emitting diode, 24R, 24G, 24B ... photodiode, 25 ... partition wall, 30 ... housing, 31 ... housing base, 32 ... upper housing 33 ... lower part of housing, 34, 35 ... side of housing, 36A ... inner frame, 36B, 36C, 36D ... spacer, 37 ... support panel, 38 ... pin, 39 ... Optical function sheet mounting means (bimetal plate), 40 ... Linear member, 41 ... Mounting portion, 50 ... Light diffusion plate, 51 ... Optical function sheet, 52 ... Light diffusion Sheet, 53 ... Prism sheet, 54 ... Polarization conversion 55 ... reflective sheet, 60 ... front panel, 61 ... first substrate, 62 ... color filter, 63 ... overcoat layer, 64 ... transparent first electrode (Common electrode), 65 ... alignment film, 66 ... polarizing plate (polarizing film / polarizing sheet), 70 ... rear panel, 71 ... second substrate, 72 ... switching element, 74 ... transparent second electrode, 75 ... alignment film, 76, 76 '... polarizing plate (polarizing film / polarizing sheet), 77 ... insulating layer, 80 ... planar light source device control circuit , 81... Arithmetic circuit, 82... Storage device (memory), 85... Liquid crystal display device drive circuit, 86... Timing controller, 90. Arithmetic circuit, 92... Storage device (memory), 93. LED drive circuit, 94 ... photodiode control circuit, 95R, 95G, 95B ... switching device, 96 ... LED driving power source (constant current source)

Claims (14)

A planar light source device for illuminating a transmissive liquid crystal display device arranged in front,
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
With
(E) a linear member that is disposed in front of the optical function sheet and has ends attached to both sides of the front surface of the housing;
A planar light source device, further comprising:   The planar light source device according to claim 1, wherein the linear member extends in a horizontal direction. It is composed of P × Q planar light source units corresponding to the P × Q display area units when assuming that the display area of the liquid crystal display device is divided into P × Q virtual display area units,
The planar light source device according to claim 1, wherein the light emission states of the P × Q planar light source units are individually controlled. A transmissive liquid crystal display device and a liquid crystal display device assembly including a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical functional sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
The planar light source device comprises:
(E) a linear member that is disposed in front of the optical function sheet and has ends attached to both sides of the front surface of the housing;
And a liquid crystal display device assembly.   The liquid crystal display device assembly according to claim 4, wherein the linear member extends in a horizontal direction. It is composed of P × Q planar light source units corresponding to the P × Q display area units when assuming that the display area of the liquid crystal display device is divided into P × Q virtual display area units,
The liquid crystal display device assembly according to claim 4, wherein the light emission states of the P × Q planar light source units are individually controlled. A transmissive liquid crystal display device and a liquid crystal display device assembly including a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate and transmits light emitted from the light diffusing plate;
With
The optical function sheet is suspended from the upper part of the support panel provided in the liquid crystal display device via the optical function sheet mounting means.
A liquid crystal display device assembly, wherein the distance between the liquid crystal display device and the optical function sheet is controlled by the operation of the optical function sheet mounting means. The optical function sheet mounting means consists of a bimetal plate,
The temperature of the optical function sheet mounting means is increased by the heat generated by the light source, and as a result, the shape of the optical function sheet mounting means changes, and the optical function sheet is moved in a direction away from the liquid crystal display device. Item 8. The liquid crystal display device assembly according to Item 7. It is composed of P × Q planar light source units corresponding to the P × Q display area units when assuming that the display area of the liquid crystal display device is divided into P × Q virtual display area units,
The liquid crystal display device assembly according to claim 7, wherein the light emission states of the P × Q planar light source units are individually controlled. A transmissive liquid crystal display device and a liquid crystal display device assembly including a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
With
A liquid crystal display device assembly, wherein a light diffusion sheet is disposed on a surface of a liquid crystal display device facing the planar light source device. It is composed of P × Q planar light source units corresponding to the P × Q display area units when assuming that the display area of the liquid crystal display device is divided into P × Q virtual display area units,
The liquid crystal display device assembly according to claim 10, wherein the light emission states of the P × Q planar light source units are individually controlled. A transmissive liquid crystal display device and a liquid crystal display device assembly including a planar light source device,
The planar light source device
(A) housing,
(B) a light source disposed inside the housing;
(C) a light diffusing plate that is fixed to the front surface of the housing and diffuses / transmits light emitted from the light source; and
(D) An optical function sheet that is disposed in front of the light diffusing plate, is attached to the upper portion of the front surface portion in a state of being suspended from the upper portion of the front surface portion of the housing, and transmits light emitted from the light diffusing plate;
With
The surface of the liquid crystal display device facing the planar light source device is composed of a polarizing plate,
The liquid crystal display device assembly, wherein the polarizing plate has a light diffusion function.   The liquid crystal display device assembly according to claim 12, wherein a light diffusing material is fixed to an outer surface of the polarizing plate. It is composed of P × Q planar light source units corresponding to the P × Q display area units when assuming that the display area of the liquid crystal display device is divided into P × Q virtual display area units,
The liquid crystal display device assembly according to claim 12, wherein the light emission states of the P × Q planar light source units are individually controlled.