JP2012238462A - Light mixing unit, planar light source device and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light mixing unit in which luminance unevenness and color unevenness are suppressed with a compact structure using a plurality of light sources with different characteristics.SOLUTION: The light mixing unit includes a light source 6, a light source 10, and a light intensity distribution shaping member 110. The light source 6 emits a light beam 600. The light source 10 emits a light beam 1000 having an angle intensity distribution wider than the light beam 600. The light intensity distribution shaping member 110 changes the angle intensity distribution of the light beam 600 in the angle intensity distribution shaping region and makes the light beam 600 and the light beam 1000 enter from a light incident surface and mix them to emit as linear light 809. The light beam 600 enters inclined to a reference plane of the light intensity distribution shaping member 110 and propagates while reflecting in the angle intensity distribution shaping region, and the light beam 1000 enters nearly perpendicularly to the reference plane of the light intensity distribution shaping member 110.

Description

  The present invention relates to a light mixing unit, a surface light source device, and a liquid crystal display device in which light emitted from a plurality of light sources having different characteristics is mixed to obtain light having a uniform intensity distribution.

  The liquid crystal display element included in the liquid crystal display device does not emit light by itself. For this reason, the liquid crystal display device includes a backlight device on the back surface of the liquid crystal display element as a light source for illuminating the liquid crystal display element. Conventionally, a cold cathode fluorescent lamp (hereinafter referred to as CCFL (Cold Cathode Fluorescent)) that obtains white light by applying a phosphor on the inner wall of a glass tube has been the mainstream as a light source of a backlight device. However, in recent years, with the dramatic improvement in performance of light emitting diodes (hereinafter, LEDs (Light Emitting Diodes)), the demand for backlight devices using LEDs as light sources is rapidly increasing.

  Examples of elements called LEDs include single-color LEDs and white LEDs. The monochromatic LED obtains monochromatic light such as red, green, or blue by direct light emission of the LED. The white LED includes a blue LED and a yellow phosphor in a package. The yellow phosphor is excited by blue light. Thereby, the white LED obtains white light. In particular, white LEDs have high luminous efficiency and are effective in reducing power consumption. For this reason, white LEDs are widely used as light sources for backlight devices. Note that a single color is a color that is only one color and is not mixed with other colors. Monochromatic light is single light having a narrow wavelength width.

  On the other hand, the white LED has a wide wavelength bandwidth. For this reason, the white LED has a problem that the color reproduction range is narrow. The liquid crystal display device includes a color filter inside the liquid crystal display element. The liquid crystal display device performs color expression by taking out only the spectral ranges of the red, green, and blue wavelengths with this color filter. A light source having a continuous spectrum with a wide wavelength bandwidth such as a white LED needs to increase the color purity of the display color of the color filter in order to widen the color reproduction range. That is, the wavelength band that transmits the color filter is set narrow. However, if the wavelength band that passes through the color filter is set narrow, the light utilization efficiency decreases. This is because the amount of unnecessary light that is not used for image display of the liquid crystal display element increases. Further, there arises a problem that the brightness of the display surface of the liquid crystal display element is lowered and further the power consumption of the liquid crystal display device is increased.

  White LEDs have a small amount of energy in the red spectrum, particularly in the 600 nm to 700 nm band. That is, if a color filter having a narrow wavelength band width is used to increase the color purity in a wavelength range of 630 to 640 nm, which is preferable as pure red, there is a problem that the amount of transmitted light is extremely reduced. Therefore, there arises a problem that the luminance is remarkably lowered.

  In recent years, backlight devices using monochromatic LEDs or lasers with high color purity as light sources have been proposed as measures for improving such problems. High color purity means that the wavelength width is narrow and the monochromaticity is excellent. In particular, the laser has a very excellent monochromaticity and a high luminous efficiency. Therefore, it has become possible to provide a liquid crystal display device that employs a laser light source and displays a high-luminance image with a wide color reproduction range. In addition, it has become possible to provide a liquid crystal display device with low power consumption by employing a laser as a light source.

  A monochromatic LED or laser light source emits monochromatic light. For this reason, in order to generate white light using a monochromatic light source, the backlight device needs to include red, green, and blue light sources. That is, the backlight device needs to include different light sources that emit light of the three primary colors. The backlight device mixes light emitted from these light sources to generate white. At this time, if there is unevenness in the spatial intensity distribution on the display surface of the liquid crystal display element of each color, it will appear as unevenness in color. That is, the light intensity unevenness of each color appears as color unevenness when mixed to generate white.

  In order to solve this problem, it is necessary to improve the uniformity of the spatial intensity distribution in the plane of each color. However, light emitted from light sources having different light emission principles and light emitting element material properties have different divergence angles and light emission efficiencies. For this reason, the number and arrangement method of each light source are different. For these reasons, it is necessary to provide an optimum means for making the spatial intensity distribution in the plane corresponding to each light source uniform.

  A conventional backlight device suppresses uneven color using a dedicated light guide plate that matches the characteristics of each light source. For example, Patent Document 1 proposes a backlight device for a flat display panel provided with a dedicated light guide plate for each color light source. The backlight device for a flat display panel includes a light source different for each color and a light guide plate corresponding to the light source of each color. The backlight device has a structure in which these light guide plates are laminated. The backlight device generates white illumination light by adding together monochromatic planar light emitted from each light guide plate. This configuration can optimize the structure of each light guide plate to the characteristics of the corresponding light source. Therefore, it is possible to improve the uniformity of the spatial intensity distribution in the plane of each color, and to suppress color unevenness. The in-plane spatial intensity distribution is a distribution indicating the level of light intensity with respect to a two-dimensional position on an arbitrary plane.

JP-A-6-138458

  However, the above configuration has a plurality of stacked light guide plates. For this reason, the above-described configuration has a problem of increasing the size of the backlight device particularly in the thickness direction of the device.

  The present invention has been made in view of the above, and provides a light mixing unit, a surface light source device, and a liquid crystal display device that suppress unevenness in light intensity and color in a compact configuration while using a plurality of light sources having different characteristics. The purpose is to obtain. Since the backlight device is a light source that illuminates the display surface of the liquid crystal display element, it has a function as a surface light source device.

  In order to solve the above-described problems and achieve the object, the light mixing unit of the present invention includes a first light source that emits a first light beam, and a second light source having a wider angular intensity distribution than the first light beam. A second light source that emits a light beam, and an angular intensity distribution shaping region, wherein the angular intensity distribution of the first light ray is changed in the angular intensity distribution shaping region, and the first light beam and the second light beam are changed. A light intensity distribution shaping member that enters from the light incident surface and mixes and emits as linear light, and the first light beam is incident with an inclination with respect to a reference plane of the light intensity distribution shaping member. The second light beam propagates while being reflected at the angular intensity distribution shaping region, and is incident substantially perpendicular to the reference plane of the light intensity distribution shaping member.

  The present invention can provide a compact light mixing unit that mixes light emitted from a plurality of light sources having different characteristics while suppressing light intensity unevenness and color unevenness.

It is a block diagram which shows typically the structure of the liquid crystal display device in Embodiment 1 of this invention. It is a block diagram which shows typically the structure of the liquid crystal display device in Embodiment 1 of this invention. It is a block diagram which shows the liquid crystal display element in Embodiment 1 of this invention, and the drive method of a light source. It is the block diagram which showed arrangement | positioning of the light intensity distribution shaping member and light source in Embodiment 1 of this invention. It is the characteristic view which showed the angular intensity distribution on the XY plane of the emitted light of the liquid crystal display device in Embodiment 1 of this invention. It is the characteristic view which showed the angular intensity distribution on the XY plane of the emitted light of the liquid crystal display device in Embodiment 1 of this invention. It is the block diagram which showed arrangement | positioning of the light intensity distribution shaping member and light source in Embodiment 1 of this invention. It is a block diagram which shows typically the structure of the liquid crystal display device in Embodiment 1 of this invention. It is the block diagram which showed arrangement | positioning of the light intensity distribution shaping member and light source in Embodiment 1 of this invention. It is a block diagram which shows typically the structure of the liquid crystal display device in Embodiment 2 of this invention. It is a block diagram which shows typically the structure of the liquid crystal display device in Embodiment 2 of this invention. It is a block diagram which shows typically the structure of the liquid crystal display device in Embodiment 2 of this invention.

  Embodiments of a backlight device and a liquid crystal display device according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment.

Embodiment 1 FIG.
FIG. 1 is a diagram schematically showing a configuration of a liquid crystal display device 800 which is a transmissive display device according to the first embodiment of the present invention. In order to facilitate the description of the drawing, the short side direction of the liquid crystal optical element 1 is defined as the Y-axis direction, the long side direction is defined as the X-axis direction, and the direction perpendicular to the XY plane is defined as the Z-axis direction. Let the display surface 1a side be the + Z-axis direction. Further, the upward direction of the liquid crystal display device is defined as the + Y axis direction, and the light emission directions of the first light source 6 and the second light source 10 described later are defined as the + X axis direction.

  As shown in FIG. 1, the liquid crystal display device 800 includes a transmissive liquid crystal display element 1, an optical sheet 31, an optical sheet 32, a backlight device 303, and a light reflecting sheet 15. These components 1, 31, 32, 303, and 15 are arranged in the Z-axis direction. The liquid crystal display element 1 has a display surface 1a parallel to an XY plane including an X axis and a Y axis orthogonal to the Z axis. The X axis and the Y axis are orthogonal to each other. The optical sheet 31 is a first optical sheet. The optical sheet 32 is a second optical sheet.

  FIG. 2 is a configuration diagram showing the liquid crystal display device 800 shown in FIG. 1 from the −Z-axis direction. For ease of explanation, the light reflecting sheet 15 is omitted. As shown in FIG. 1 and FIG. 2, the backlight device 303 includes a light guide plate 811, a light diffuse reflection part 812, a light intensity distribution shaping member 110, a light source 6, and a light source 10. The light source 6 is a first light source, and the light source 10 is a second light source. Note that the backlight device 303 has a function of a surface light source device that emits planar light. In FIG. 1, the light source 10 overlaps with the light source 6, and therefore is indicated by a broken line for distinction.

  FIG. 3 is a block diagram showing a method for driving the liquid crystal display element 1 and the light sources 6 and 10. The liquid crystal display element driving unit 52 drives the liquid crystal display element 1. The light source driving unit 53a drives the light source 6 that is the first light source. The light source driving unit 53b drives the light source 10 that is the second light source. The control unit 51 controls the liquid crystal display element driving unit 52 and the light source driving units 53a and 53b.

  The control unit 51 performs image processing on the video signal 54 supplied from a signal source (not shown) to generate control signals (the liquid crystal display element control signal 55 and the light source control signals 56a and 56b). The control unit 51 supplies these control signals to the liquid crystal display element driving unit 52 and the light source driving units 53a and 53b. The light source driving unit 53 a drives the light source 6 based on the light source control signal 56 a from the control unit 51 to emit light from the light source 6. The light source driving unit 53 b drives the light source 10 based on the light source control signal 56 b from the control unit 51 to emit light from these light sources 10.

  In addition, the control part 51 can control the light source drive parts 53a and 53b, and can adjust the ratio of the light intensity of the emitted light 600 and the light intensity of the emitted light 1000. The outgoing light 600 is the first light. Moreover, the emitted light 1000 is the second light.

  The light sources 6 and 10 are types of light sources having different angular intensity distributions. The light source 6 is made of a laser element, for example. The angular intensity distribution of the light source 6 has a Gaussian distribution shape having a small full width at half maximum (angle at the maximum half value). The light source 6 emits red light having a peak at 640 nm and has a very monochromatic spectrum with a full width at half maximum of 1 nm.

  The light source 10 is composed of, for example, an LED element. The angular intensity distribution has a Lambertian distribution shape having a large full width at half maximum. The light source 10 emits blue-green (cyan) light having peaks near 450 nm and 530 nm and having a continuous spectrum in a band from 420 nm to 580 nm. Specifically, a green phosphor that absorbs blue light and emits green light is filled in a package including a blue LED that emits light directly. Moreover, as such a light source 10, for example, a light source other than an LED may be adopted as an excitation light source, and a light source that excites a green phosphor by the excitation light source to emit blue-green light may be employed. In addition, for example, a light source that emits blue-green light by exciting a phosphor that emits blue and green light with a light source that emits light having a wavelength in the ultraviolet region may be employed. For example, it is good also as a structure provided with blue LED and green LED of direct light emission.

  The outgoing light 600 emitted from the light source 6 and the outgoing light 1000 emitted from the light source 10 enter the light guide plate 811 via the light intensity distribution shaping member 110. The outgoing light 600 and outgoing light 1000 incident on the light guide plate 811 are converted into illumination light 810 directed in the + Z-axis direction by the light diffusing / reflecting part 812 provided on the back surface (−Z-axis side) of the light guide plate 811. The illumination light 810 is emitted toward the back surface 1 b of the liquid crystal display element 1. That is, the illumination light 810 is white planar light in which the red emitted light 600 and the blue-green emitted light 1000 are mixed. That is, the light guide plate 811 has a function as a surface emitting light guide plate.

  The illumination light 810 passes through the second optical sheet 32 and the first optical sheet 31 and is irradiated on the back surface 1 b of the liquid crystal display element 1. Here, the first optical sheet 31 has a function of condensing light emitted from the backlight device 303 in a normal direction to the screen of the liquid crystal display device 800. The second optical sheet 32 suppresses optical influences such as fine illumination unevenness.

  A light reflection sheet 15 is disposed immediately below the light diffuse reflection portion 812 (−Z axis direction). The light radiated from the light guide plate 811 and the light diffuse reflection part 812 to the back side (−Z axis direction) is reflected by the light reflection sheet 15 and used as illumination light for irradiating the back surface 1 b of the liquid crystal display element 1. . As the light reflecting sheet 15, for example, a light reflecting sheet based on a resin such as polyethylene terephthalate or a light reflecting sheet in which a metal is deposited on the surface of the substrate can be used.

  The liquid crystal display element 1 has a liquid crystal layer parallel to an XY plane perpendicular to the Z-axis direction. The display surface 1a of the liquid crystal display element 1 has a rectangular shape. The X-axis direction and the Y-axis direction shown in FIG. 1 are directions along two mutually orthogonal sides of the display surface 1a. The liquid crystal display element driving unit 52 changes the light transmittance of the liquid crystal layer in units of pixels in accordance with the control signal (liquid crystal display element control signal 55) supplied from the control unit 51. Each pixel further includes three subpixels, and each subpixel includes a color filter that transmits only red light, green light, and blue light. The liquid crystal display element driving unit 52 generates a color image by controlling the transmittance of each sub-pixel. As a result, the liquid crystal display element 1 spatially modulates the illumination light incident from the backlight device 303 to generate image light. The liquid crystal display element 1 can emit this image light from the display surface 1a. Note that image light is light having image information. According to the first embodiment, for example, the light source driving units 53 a and 53 b are individually controlled by the control unit 51, and the amount of red light emitted from the first light source 6 and the second light source 10 are controlled. It is possible to adjust the ratio of the amount of emitted blue-green light. For this reason, it is possible to realize low power consumption by adjusting the light emission amount of each light source according to the ratio of each color light intensity required for each video signal 54.

  The light guide plate 811 is made of a transparent material. The light guide plate 811 is a plate-like member. As the transparent material, for example, acrylic resin (PMMA) can be employed. The light guide plate 811 can be a plate-like member having a thickness of 3 mm, for example.

  The light diffusing / reflecting part 812 is disposed so as to be in contact with the −Z-axis direction surface of the light guide plate 811. The light diffusing / reflecting unit 812 has a function of converting light having a linear spatial intensity distribution incident on the light guide plate 811 into light having a planar spatial intensity distribution. The light diffuse reflection unit 812 has a function of emitting light having the planar spatial intensity distribution toward the liquid crystal display element 1. Linear light is light having this linear spatial intensity distribution. The planar light is light having this planar spatial intensity distribution.

  For example, the light diffuse reflection part 812 can adopt a configuration in which the diffuse reflection material 812a is applied in the form of dots on the back surface of the light guide plate 811. At that time, the density of the diffuse reflection material 812a applied in a dot shape is sparse in the vicinity of the light incident surface 811a and becomes denser as the distance from the light incident surface 811a increases. The density of the diffuse reflector 812a is the most dense in the vicinity of the end surface of the light guide plate 811 in the + X-axis direction. This makes the spatial intensity distribution in the plane of the illumination light 810 in the XY plane uniform. The illumination light 810 is illumination light emitted from the light guide plate 811.

  The emitted light 600 has a point-like spatial intensity distribution when emitted from the light source 6. The emitted light 1000 has a point-like spatial intensity distribution when emitted from the light source 10. The light intensity distribution shaping member 110 converts the outgoing lights 600 and 1000 having a point-like spatial intensity distribution into light 809 having a linear spatial intensity distribution. The widths of the linear light 809 generated at this time in the Z-axis direction and the Y-axis direction have the same size as the widths of the light exit surfaces 110b of the light intensity distribution shaping member 110 in the Z-axis direction and the Y-axis direction. .

  In the first embodiment, the outgoing light 600 and the outgoing light 1000 are mixed. As a result, the linear light 809 becomes linear white light. The emitted light 600 is red light emitted from the light source 6. The emitted light 1000 is blue-green light emitted from the light source 10. The linear light 809 is light emitted from the light emitting surface 110 b of the light intensity distribution shaping member 110.

  Further, the light intensity distribution shaping member 110 has a function of approximately approximating the angular intensity distribution of the emitted light 600, 1000. Here, the angular intensity distribution represents a change in light intensity for each angle. Specifically, the light intensity distribution shaping member 110 approximates the angular intensity distribution of the light 600 to the angular intensity distribution of the light 1000 on a plane (XY plane) parallel to the plane where the light source 6 and the light source 10 are arranged. Has the function of expanding the angular intensity distribution. Here, the angular intensity distribution of the light 600 when emitted from the light source 6 is narrow. Further, the angular intensity distribution of the light 1000 when emitted from the light source 10 is wide. As described above, the light 600 has a Gaussian distribution shape with a small full width at half maximum. The light 1000 has a Lambertian distribution shape with a large full width at half maximum.

  The detailed structure of the light intensity distribution shaping member 110 will be described below.

  The light intensity distribution shaping member 110 is composed of a plate-like member. The light intensity distribution shaping member 110 is, for example, a plate-like member having a thickness of 2 mm. Further, the light intensity distribution shaping member 110 is disposed in parallel with the XY plane and at substantially the same position as the light guide plate 811 in the Z-axis direction. That is, the light intensity distribution shaping member 110 is disposed at a position where the light emitting surface 110b and the light incident surface 811a face each other. The light intensity distribution shaping member 110 is, for example, 90 mm in the X-axis direction and 255 mm in the Y-axis direction. The light intensity distribution shaping member 110 is made of an acrylic resin transparent material such as PMMA, for example.

  As shown in FIGS. 1 and 2, the light incident surface 110 a of the light intensity distribution shaping member 110 faces the light emitting portions of the first light source 6 and the second light source 10. Here, the light emitting part is a part from which the outgoing lights 600 and 1000 are emitted from the light sources 6 and 10. Further, the light exit surface 110 b of the light intensity distribution shaping member 110 faces the light incident surface 810 a of the light guide plate 811.

  The first light source 6 is, for example, a light source device in which laser elements are arranged at substantially equal intervals in the Y-axis direction. The first light source 6 includes a number of laser elements that are multiples of natural numbers. Here, the natural number is a number obtained by starting from 1 and adding 1 to 1 in succession, and does not include zero. The second light source 10 is, for example, a light source device in which LED elements are arranged at substantially equal intervals in the Y-axis direction. The second light source 10 includes a natural number of LED elements.

  In the first embodiment, the first light source 6 has six laser elements 6a, 6b, 6c, 6d, 6e, and 6f arranged in the Y-axis direction. The second light source 10 has three LED elements 10a, 10b, and 10c arranged in the Y-axis direction. Laser element 6a, LED element 10a, laser element 6b, laser element 6c, LED element 10b, laser element 6d, laser element 6e, LED element 10c, and laser element 6f in this order from the upper side of FIG. 2 (the Y-axis direction in FIG. 2). Lined up.

  The laser elements 6a, 6b, 6c, 6d, 6e, and 6f of the first light source 6 are arranged at positions rotated clockwise or counterclockwise as viewed from the −Z axis direction with the Z axis as a rotation axis. ing. For this reason, the emitted light 600 is emitted in a direction having a predetermined angle from the X-axis direction on the XY plane. That is, the light emitting unit that emits the first light beam 600 is arranged in a direction rotated by an arbitrary angle from the X-axis direction with the Z axis as the rotation axis.

  The laser elements 6a, 6b, 6c, 6d, 6e, and 6f that are adjacent to each other are arranged so as to rotate in the opposite directions by the same angle with respect to the X axis. That is, the laser elements 6a, 6b, 6c, 6d, 6e, and 6f that are adjacent to each other are different in positive / negative only in the rotation direction, and all have the same rotation angle. As shown in FIG. 2, the laser element 6a is arranged to rotate counterclockwise by a predetermined angle with the Z axis as a rotation axis. On the other hand, the adjacent laser elements 6b are arranged to rotate clockwise by the same angle with the Z axis as the rotation axis. Further, the laser element 6c adjacent to the laser element 6b is arranged to rotate counterclockwise by the same angle with the Z axis as the rotation axis. The light emitting unit that emits the first light beam 600 of the first light source 6 is disposed to face the light incident surface 110 a of the light intensity distribution shaping member 110.

  On the other hand, LED element 10a, 10b, 10c is arrange | positioned so that the emitted light 1000 may be radiate | emitted in the X-axis direction. That is, the LED elements 10a, 10b, and 10c are arranged with the light emitting portion directed in the X-axis direction. The light emitting portions of the LED elements 10 a, 10 b, and 10 c are arranged to face the light incident surface 110 a of the light intensity distribution shaping member 110. In addition, the light emission part of LED element 10a, 10b, 10c is a part which radiate | emits the 2nd light ray 1000. FIG.

  FIG. 4 is a configuration diagram showing the arrangement of the light intensity distribution shaping member 110, the first light source 6, and the second light source 10. FIG. 4 is an enlarged view of a part of the light intensity distribution shaping member 110. FIG. 4 shows the shape of the light intensity distribution shaping member 110 in the XY plane. FIG. 4 shows the shape of the light intensity distribution shaping member 110.

  Of the light incident surface 110a of the light intensity distribution shaping member 110, the light incident surfaces 1106a, 1106b, 1106c, 1106d, 1106e, 1106f facing the laser elements 6a, 6b, 6c, 6d, 6e, 6f are alternately Z-axis. It has an irregular shape that rotates around. Specifically, the light incident surfaces 1106a, 1106b, 1106c, 1106d, 1106e, and 1106f facing the laser elements 6a, 6b, 6c, 6d, 6e, and 6f are the main parts of the first emitted light 600 emitted from the corresponding laser elements. It is arranged perpendicular to the light beam. Here, the principal ray refers to a ray traveling in the angular direction having the maximum intensity in the angular intensity distribution.

  A surface facing the laser element 6a is a light incident surface 1106a (not shown). The surface facing the laser element 6b is a light incident surface 1106b. The surface facing the laser element 6c is a light incident surface 1106c. The surface facing the laser element 6d is a light incident surface 1106d. The surface facing the laser element 6e is a light incident surface 1106e. A surface facing the laser element 6f is a light incident surface 1106f (not shown).

  In the first embodiment, the direction of the principal ray of each first light ray 600 emitted from the first light source 6 is directed to a direction rotated ± 20 degrees from the + X axis direction with the Z axis as the rotation axis. The first light beam 600 emitted from each of the laser elements 6a, 6c, and 6e is emitted in a direction rotated 20 degrees counterclockwise when viewed from the −Z axis direction on the XY plane. The light beams 600 respectively emitted from the laser elements 6b, 6d, and 6f are emitted in a direction rotated 20 degrees clockwise as viewed from the −Z axis direction on the XY plane.

  Further, the light incident surfaces 1106a, 1106c, and 1106e rotate 20 degrees counterclockwise when viewed from the −Z-axis direction with the Z-axis as a rotation axis. The light incident surfaces 1106b, 1106d, and 1106f rotate 20 degrees clockwise as viewed from the −Z axis direction with the Z axis as the rotation axis. That is, the light incident surfaces 1106a, 1106b, 1106c, 1106d, 1106e, 1106f are formed to be inclined with respect to the YZ plane. The YZ plane is a reference plane. FIG. 4 shows the laser elements 6b, 6c, 6d, and 6e and the light incident surfaces 1106b, 1106c, 1106d, and 1106e.

  Among the light incident surfaces 110a of the light intensity distribution shaping member 110, the light incident surfaces 1110a, 1110b, and 1110c that face the LED elements 10a, 10b, and 10c are second light emitted from the corresponding LED elements 10a, 10b, and 10c. It is arranged perpendicular to the chief ray of the ray 1000. The surface facing the LED element 10a is a light incident surface 1110a (not shown). The surface facing the LED element 10b is a light incident surface 1110b. The surface facing the LED element 10c is a light incident surface 1110c (not shown).

  In the first embodiment, the principal ray of each second light ray 1000 emitted from the second light sources 10a, 10b, and 10c is emitted toward the + X-axis direction. Corresponding light incident surfaces 1110a, 1110b, and 1110c are arranged in parallel to the YZ plane. FIG. 4 shows the LED element 10b and the light incident surface 1110b.

  That is, the light intensity distribution shaping member 110 includes the number of laser elements 6a, 6b, 6c, 6d, 6e, and 6f included in the first light source 6 and the number of LED elements 10a, 10b, and 10c included in the second light source 10. The same number of light incident surfaces 1106a, 1106b, 1106c, 1106d, 1106e, 1106f, 1110a, 1110b, 1110c as the total sum of the above.

  The light intensity distribution shaping member 110 has a fine optical structure 111 on the surface of the light incident surface 110a facing the first light source 6. In the first embodiment, the fine optical structure 111 is provided on the light incident surfaces 1106a, 1106b, 1106c, 1106d, 1106e facing the laser elements 6a, 6b, 6c, 6d, 6e, 6f.

  The fine optical structure 111 has a function of changing the traveling direction of incident light by refraction. As shown in FIG. 4, for example, the fine optical structure 111 has a configuration in which cylindrical side surface-shaped concave shapes are formed on the light incident surface 110 a at regular intervals in the Y-axis direction. Here, the central axis of the cylinder is parallel to the Z axis. The concave shape shown in FIG. 4 is a side shape cut by a plane passing through the central axis of the cylinder. A cross section obtained by cutting the fine optical structure 111 along the XY plane has a concave arc shape on the first light source 6 side. The cross section obtained by cutting the light incident surface 110a along the Z-X plane has a linear shape extending in the Z-axis direction.

  The fine optical structure 111 of the light intensity distribution shaping member 110 according to the first embodiment has a concave arc shape with a radius of 40 μm on the XY plane. The center of the arc shape is on the plane of each light incident surface 1106a, 1106b, 1106c, 1106d, 1106e. The depth of the concave shape is 20 μm. The interval between the arc shapes is 80 μm at the center of the arc.

  The first outgoing light 600 incident on the light incident surface 110a is diffused by the fine optical structure 111 when entering the light incident surface 110a. Therefore, the full angle of the angular intensity distribution of the first outgoing light 600 incident on the light intensity distribution shaping member 110 is larger than the full angle of the angular intensity distribution immediately after emitted from the first light source 6. The first outgoing light 600 travels in a random direction within the light intensity distribution shaping member 110. However, in FIG. 4, in order to clarify the optical path of the first light beam 600, the diffusion action by the fine optical structure 111 is not considered.

  In the first embodiment, the first outgoing light 600 emitted from the first light source 6 has a narrow angular intensity distribution with a full angle of 35 degrees on the XY plane. The shape of the angular intensity distribution of the outgoing light 600 has a substantially Gaussian distribution. The emitted lights 600a, 600b, 600c, 600d, 600e, and 600f emitted from the laser elements 6a, 6b, 6c, 6d, 6e, and 6f are added together in the light intensity distribution shaping member 110. Thereby, the full angle of the angular intensity distribution of the outgoing light 600 on the light outgoing surface 110b is a large angle.

  More specifically, the laser elements 6a, 6c, and 6e are arranged so as to rotate 20 degrees counterclockwise when viewed from the −Z-axis direction with respect to the X-axis direction around the Z-axis. The laser elements 6b, 6d, and 6f are arranged so as to rotate 20 degrees clockwise around the Z axis with respect to the X axis direction when viewed from the −Z axis direction. As a result, the axes of the outgoing light beams 600a, 600c, and 600e are inclined 20 degrees counterclockwise as viewed from the −Z-axis direction with respect to the + X-axis direction and centered on the Z-axis. The axes of the emitted light beams 600b, 600d, and 600f are inclined 20 degrees clockwise with respect to the + X-axis direction as viewed from the −Z-axis direction around the Z-axis. That is, the axes of the outgoing light beams 600a, 600c, and 600e and the outgoing light beams 600b, 600d, and 600f are directed in directions symmetric with respect to the X axis.

  Here, the axis of the light beam refers to an axis in the angular direction that is a weighted average of the angular intensity distribution of the light beam in an arbitrary plane. The angle that becomes the weighted average is obtained by weighting the light intensity to each angle and averaging the angles. When the peak position of the light intensity is deviated from the center of the angular intensity distribution, the axis of the light beam does not become the angle of the peak position of the light intensity. The ray axis is the angle of the center of gravity position in the area of the angular intensity distribution.

  In the angular intensity distribution of the light beams obtained by adding the light beams of the emitted light beams 600a, 600c, and 600e and the emitted light beams 600b, 600d, and 600f, the light beam axis is in the + X-axis direction. Further, the angular intensity distribution of the light beams obtained by adding these light beams has a wider full angle than the angular intensity distributions of the original outgoing lights 600a, 600c, 600e and outgoing lights 600b, 600d, 600f.

  5 and 6 are characteristic diagrams showing angular intensity distributions on the XY plane of the emitted light 600 and the emitted light 1000 in the first embodiment. FIG. 5 shows the addition of the angular intensity distribution 121a of the outgoing lights 600a, 600c, and 600e on the light outgoing face 110b of the light intensity distribution shaping member 110 and the angular intensity distribution 121b of the outgoing lights 600b, 600d, and 600f on the light outgoing face 110b. It is a figure which shows the angular intensity distribution 122 of the obtained light. The horizontal axis indicates the angle [deg], and the vertical axis indicates the light intensity (arbitrary unit. [Au] in FIG. 5 is an abbreviation for arbitrary units). Here, the angle is an angle rotated around the Z-axis from the + X-axis direction. -As viewed from the Z-axis direction, clockwise is the positive side and counterclockwise is the negative side.

  FIG. 6 is a diagram comparing the three angular intensity distributions 100, 120, and 122. The angular intensity distribution 100 is an angular intensity distribution of the emitted light 1000 emitted from the second light source 10 and emitted from the light emitting surface 110b via the light intensity distribution shaping member 110. The angular intensity distribution 120 is an angular intensity distribution of the outgoing light 1000 immediately after being emitted from the first light source 6. The angular intensity distribution 122 is an angular intensity distribution of the emitted light 600 emitted from the first light source 6 and emitted from the light emitting surface 110 b via the light intensity distribution shaping member 110. The horizontal axis indicates the angle [deg], and the vertical axis indicates the light intensity (arbitrary unit. [Au] in FIG. 6 is an abbreviation for arbitrary units). Here, regarding the angle intensity distributions 100 and 122, the angle is an angle rotated around the Z axis from the + X axis direction. -As viewed from the Z-axis direction, clockwise is the positive side and counterclockwise is the negative side. For the angular intensity distribution 120, the angle is 0 degrees in the direction of the principal ray.

  As shown in FIG. 5, the outgoing lights 600a, 600c, and 600e on the light outgoing surface 110b of the light intensity distribution shaping member 110 have the highest intensity in the direction rotated by approximately +20 degrees (angular intensity distribution 121a). This is due to the fact that the first light sources 6a, 6c, 6e are arranged by being rotated +20 degrees around the Z axis. Further, the outgoing lights 600a, 600c, and 600e on the light outgoing surface 110b of the light intensity distribution shaping member 110 have different angular intensity distributions from the outgoing lights 600a, 600c, and 600e emitted from the first light sources 6a, 6c, and 6e. Have. The outgoing lights 600a, 600c, and 600e immediately after emitted from the first light sources 6a, 6c, and 6e have a substantially Gaussian distribution with a full angle of 35 degrees. When the emitted lights 600a, 600c, and 600e are incident on a member having a refractive index equivalent to that of the light intensity distribution shaping member 110, the angular intensity distribution is narrowed by refraction, and the full angle is approximately 24 degrees. The light intensity distribution shaping member 110 of the first embodiment has a fine optical structure 111 on the light incident surfaces 1106a, 1106c, and 1106e. The outgoing lights 600a, 600c, and 600e are diffused by the fine optical structure 111, and the entire angle of the angular intensity distribution 121a is expanded to about 40 degrees. Further, the angular intensity distribution 121a has a gently changing shape.

  The outgoing lights 600b, 600d, and 600f on the light outgoing face 110b of the light intensity distribution shaping member 110 have the highest intensity in the direction rotated by approximately −20 degrees (angular intensity distribution 121b). This is due to the fact that the first light sources 6b, 6d, 6f are arranged by being rotated by -20 degrees around the Z axis. Further, the outgoing lights 600b, 600d, and 600f on the light outgoing surface 110b of the light intensity distribution shaping member 110 have different angular intensity distributions from the outgoing lights 600b, 600d, and 600f emitted from the first light sources 6b, 6d, and 6f. Have. The outgoing lights 600b, 600d, and 600f immediately after emitted from the first light sources 6b, 6d, and 6f have a substantially Gaussian distribution with a full angle of 35 degrees. When the emitted lights 600b, 600d, and 600f are incident on a member having a refractive index equivalent to that of the light intensity distribution shaping member 110, the angular intensity distribution is narrowed by refraction, and the full angle is approximately 24 degrees. However, the light intensity distribution shaping member 110 of the first embodiment has the fine optical structure 111 on the light incident surfaces 1106b, 1106d, and 1106f. The outgoing lights 600b, 600d, and 600f are diffused by the fine optical structure 111, and the entire angle of the angular intensity distribution 121b is expanded to about 40 degrees. Further, the angular intensity distribution 121b has a gently changing shape.

  As described above, on the light exit surface 110b of the light intensity distribution shaping member 110, the angular intensity distributions 121a and 121b of the two light beams have a symmetric shape with the X axis (angle 0 degree) as the center. The axis of the light in the angular intensity distribution 122 of the light obtained by adding the emitted light 600a, 600c, 600e and the emitted light 600b, 600d, 600f is on the X axis (angle 0 degree). The full angle of the angular intensity distribution 122 is about 80 degrees.

  As shown in FIG. 6, on the XY plane, the angular intensity distribution of the outgoing light 600 emitted from the first light source 6 has a substantially Gaussian distribution shape with a narrow full width. By passing through the light intensity distribution shaping member 110, the angular intensity distribution 122 of the emitted light 600 on the light emitting surface 110b becomes a substantially Lambertian distribution shape having a wide full angle. Thus, the outgoing light 600 immediately after entering the light guide plate 811 has an angular intensity distribution approximately approximate to the outgoing light 1000 immediately after entering the light guide plate 811. A region in which the angular intensity distribution of the outgoing light 600 is approximately approximated to the angular intensity distribution of the outgoing light 1000 in this way is referred to as an angular intensity distribution shaping region of the light intensity distribution shaping member 110.

  The outgoing light 600 and the outgoing light 1000 that have entered the light intensity distribution shaping member 110 travel in the light intensity distribution shaping member 110 in the + X-axis direction. The emitted light 600 is converted by the light intensity distribution shaping member 110 into a shape whose angular intensity distribution approximates that of the emitted light 1000. Thereafter, the outgoing light 600 and the outgoing light 1000 are mixed by spreading by their own divergence angle, and become linear white light from the light outgoing surface 110b of the light intensity distribution shaping member 110 to the light incident surface 810a of the light guide plate 811. Exit toward

  As described above, according to the first embodiment, even when the backlight device includes a plurality of types of light sources having different angular intensity distributions and the number of light emitting elements to be arranged, the light intensity distribution shaping member 110 is used. It is possible to generate linear white light with no color unevenness.

  Moreover, even when the light intensity distribution shaping member 110 includes light sources having different angular intensity distributions, the light intensity distribution shaping member 110 has a function of converting these angular intensity distributions into shapes that approximate. For this reason, even when emitted as planar light from the light guide plate 811 provided behind the light intensity distribution shaping member 110, planar white light with no color unevenness in the display surface of the liquid crystal display device is obtained. A certain illumination light 810 can be generated. In addition, since the angular intensity distributions of the red light and the blue-green light constituting the illumination light 810 are equal, uneven color due to a change in the angle formed with the display surface of the liquid crystal display device can be suppressed.

  In particular, in the case of including a laser having an angular intensity distribution with a shape whose width is very narrow and abruptly changed and an LED having an angular intensity distribution with a shape whose width is very wide and gently changed, the angular intensity distribution is approximated. It was difficult to make. However, in the first embodiment, the angular intensity distribution of these light sources is approximated. Therefore, in the liquid crystal display device 800 of the first embodiment, it is possible to provide a high-quality image without color unevenness.

  Conventionally, when a light source of a different type is used as a light source of a liquid crystal display device, in order to suppress color unevenness, each light source is provided with a light guide plate suitable for the property, and the light guide plates are laminated. . Therefore, it has been difficult to reduce the thickness of the device. However, in the liquid crystal display device 800 of the first embodiment, the light intensity distribution shaping member 110 is provided to reduce the thickness of the device.

  Further, in the liquid crystal display device 800 according to the first embodiment, by adopting the light intensity distribution shaping member 110, a light guide plate provided for a plurality of light sources having different characteristics is shared, and the light sources of these light sources are guided. The axes of light rays in the optical plate thickness direction (Z-axis direction) are made to coincide. Therefore, it is possible to further suppress color unevenness.

  In the first embodiment, a laser having excellent monochromaticity is employed as the light source. For example, the wavelength bandwidth of a red monochromatic LED having a narrower wavelength bandwidth than that of a white LED is about several tens of nanometers. On the other hand, the wavelength bandwidth of the red laser is only about a few nm. Red is a color with high human sensitivity to color differences. Therefore, the difference in wavelength bandwidth between the monochromatic LED and the laser in red is felt as a more prominent difference in human vision. Here, the wavelength bandwidth is a difference in color purity.

  Therefore, among the three primary colors, the effect of reducing power consumption and improving the color purity by replacing red light with a laser is high. For these reasons, in the liquid crystal display device 800 of the first embodiment, a laser is applied to the red light source.

  Conventionally, a white LED having a continuous spectrum from blue to red and a red single-color LED having a wide wavelength bandwidth have been used. In this case, a part of the red light passes through the green filter adjacent to the spectrum, so that the green color purity is also lowered. However, in the liquid crystal display device 800 according to the first embodiment, since the red color purity is increased, the amount of red light transmitted through the green filter is reduced, and the green color purity can be improved.

  Further, in the liquid crystal display device 800, the blue light and the green light are generated by a blue-green LED including a blue single-color LED and a phosphor that absorbs the blue light and emits green light. For green, it may be possible to adopt a monochromatic LED or monochromatic laser that emits green light. However, in a simple and compact device applicable to a display, these single-color LEDs and single-color lasers are inferior in terms of low power consumption and high output as compared with multicolor LEDs using phosphors. Therefore, in the liquid crystal display device 800 according to the first embodiment, in order to simplify the device, reduce the size, and reduce power consumption, the green light uses a phosphor instead of a light emitting element such as a single color LED or a single color laser. It is said.

  In the first embodiment, a blue monochromatic LED is employed as a light source that emits blue light and excites a green phosphor. In order to further expand the color reproduction range, it is also effective to employ a blue laser instead of a blue single color LED. However, like the light source 10 of the first embodiment, when a phosphor is excited by a blue light emitting element to obtain light of other colors, it is preferable to employ an LED rather than a laser.

  This is due to the following reason. In contrast to LEDs with low current drive and low output, the laser has high output with high current drive. For this reason, the amount of heat generated from the laser during driving is very large. In addition, light emitted from the LED has a wide divergence angle, whereas light emitted from the laser has a very narrow divergence angle. For this reason, in the case of a laser, the intensity density of excitation light incident on the phosphor (the intensity of light incident per unit volume of the phosphor) is very high. A part of the light incident on and absorbed by the phosphor is converted to another wavelength and emitted to the outside, and the other light mainly becomes thermal energy. Generally, the internal conversion efficiency (the amount of light converted into light of other wavelengths with respect to the amount of light absorbed) of the phosphor is about 40% to 80%. That is, the thermal energy generated at the same time ranges from 20% to 60% of the incident light energy. Accordingly, when a laser beam having a high output and a high light intensity density is incident, the calorific value of the phosphor becomes very large.

  As the amount of heat generated by the laser itself including the phosphor increases, the temperature of the phosphor increases. Moreover, even if the calorific value of the phosphor itself increases, the temperature of the phosphor increases. When the temperature of the phosphor rises, the internal conversion efficiency of the phosphor greatly decreases, causing a decrease in luminance and an increase in power consumption on the display surface of the liquid crystal display device. Accordingly, the light source 10 in the first embodiment employs a blue-green LED including a blue LED and a phosphor that is excited by the blue light and emits green light.

  As described above, in the liquid crystal display device 800 of the first embodiment, a laser is employed only for red among the three primary colors, and a blue-green LED is employed for blue and green. The blue-green LED includes a blue single-color LED and a phosphor that absorbs the blue light and emits green light. As a result, a liquid crystal display that achieves a wide color reproduction range with low power consumption by a simple and inexpensive configuration compared to a conventional white LED, a single primary color LED of three primary colors, or a liquid crystal display device using a single primary color laser. It is possible to provide a display device.

  In the first embodiment, a red laser having a peak wavelength at 640 nm is used as the light source of the backlight device 800. However, the present invention is not limited to this. For example, red lasers having different wavelengths may be employed. For example, it is also effective to employ, as the first light source 6, an LED that emits monochromatic light that is relatively excellent in monochromaticity. However, in order to obtain a wider color reproduction region, it is more effective to adopt a laser with a narrow wavelength width as much as possible to widen the color reproduction region. Note that a laser having a narrow wavelength width is a laser excellent in monochromaticity. In the first embodiment, the second light source 10 needs to employ a light source that emits light of a complementary color necessary for producing white color with respect to the monochromatic light source 6 employed as the first light source. .

  In the first embodiment, the first light source 6 is composed of six laser elements, but the present invention is not limited to this. In the present invention, in order to approximate the angular intensity distribution of the first light source 6 to the angular intensity distribution of the second light source 10, the angular intensity distributions of the two laser elements are added and the distribution shape is shaped into an optimum shape. ing. Accordingly, the first light source 6 may be provided with a number of laser elements that is a multiple of two. At this time, it is desirable that the plurality of laser elements be regularly arranged so that the spatial intensity distribution of the light emitted from the light intensity distribution shaping member 110 is not uneven.

  In the first embodiment, the second light source 10 is composed of three LED elements, but the present invention is not limited to this. At this time, it is desirable that the arrangement intervals of the LED elements are regularly arranged so that the spatial intensity distribution of the light emitted from the light intensity distribution shaping member 110 cannot be uneven.

  In the first embodiment, the light intensity distribution shaping member 110 is an integral part, but the present invention is not limited to this. For example, the light intensity distribution shaping member 210 shown in FIG. 7 divides the light intensity distribution shaping member 110 shown in FIG. 2 at an arbitrary position in the light source arrangement direction (Y-axis direction in FIG. 2). As shown in FIG. 8, the light intensity distribution shaping members 210 are arranged in the Y-axis direction.

  Thereby, even when the size of the light guide plate 811 changes, the same components can be used. That is, the number of light intensity distribution shaping members 210 to be arranged may be changed depending on the size of the light guide plate 811.

  In the light intensity distribution shaping member 210 of FIG. 7, the side surfaces 210c and 210d are formed perpendicular to the light emitting surface 210b. Further, the reflection of light generated on the side surfaces 210c and 210d is regular reflection due to a difference in refractive index between the light intensity distribution shaping member 210 and the air layer. For this reason, the side surface 210c, 210d has no influence on the angular intensity distribution shape of the outgoing light 600 and the outgoing light 1000.

  Further, instead of the light intensity distribution shaping member 210, for example, the light intensity distribution shaping member 310 of FIG. 9 can be adopted. The side surfaces 310c and 310d of the light intensity distribution shaping member 310 have a curvature. This is different from the side surfaces 210c and 210d of the light intensity distribution shaping member 210. By designing the shapes of the side surfaces 310c and 310d, the angular intensity distribution shape of the outgoing light 600 emitted from the first light source 6 can be finely adjusted.

Embodiment 2. FIG.
FIG. 10 is a diagram schematically showing a configuration of a liquid crystal display device 2000 which is a transmissive display device according to the second embodiment of the present invention. The liquid crystal display device 2000 of the second embodiment is different from the liquid crystal display device 800 of the first embodiment in that the light intensity distribution shaping member 110 is provided on the back side of the light reflecting sheet 15 (the −Z axis direction in FIG. 1). Is different. Another difference is that a cylindrical mirror 500 as a light traveling direction changing member is newly added between the exit surface 110b of the light intensity distribution shaping member 110 and the light incident surface 811a of the light guide plate 811. Constituent elements that are the same as those shown in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

  The reflection surface 500 a of the cylindrical mirror 500 is disposed to face the light emission surface 110 b of the light intensity distribution shaping member 110. The reflective surface 500a is also arranged to face the light incident surface 811a of the light guide plate 811. The light intensity distribution shaping member 110 is disposed substantially parallel to the light guide plate 811. As shown in FIG. 10, the cross section cut along the XZ plane of the reflective surface 500a has a concave arc shape on the light incident surface 811a side. Moreover, the cross section cut | disconnected by the XY plane of the reflective surface 500a is a linear form extended in a Y-axis direction. The reflective surface 500a is a reflective surface of the cylindrical mirror 500.

  Outgoing light 600 and outgoing light 1000 emitted from the first light source 6 and the second light source 10 enter the light intensity distribution shaping member 110 and travel in the −X-axis direction. Thereafter, the emitted light 600 and the emitted light 1000 are emitted from the light emitting surface 110b toward the cylindrical mirror 500. The cylindrical mirror 500 has a function as a light traveling direction changing member, and the light incident surface of the light guide plate 811 directs the emitted light 600 and the emitted light 1000 emitted from the light emitting surface 110b in the −X axis direction to the + X axis direction. It emits toward 811a.

  In the first embodiment, the light intensity distribution shaping member 110 is arranged on a plane parallel to the display surface 1a of the liquid crystal display device 800 in order to eliminate the problem of color unevenness that occurs when light sources having different characteristics are employed. Thus, the liquid crystal display device 800 is thinned. According to the second embodiment, the light intensity distribution shaping member 110 is arranged on the back side (−Z axis direction) of the light guide plate 811 or the light reflection sheet 15. Thereby, the bezel of the liquid crystal display device 800 can be made narrower than in the first embodiment. Here, the bezel refers to a member of an outer frame surrounding the display screen periphery of the liquid crystal display device.

  In the second embodiment, the semicircular cylindrical mirror 500 is used as the light traveling direction changing member, but the present invention is not limited to this. For example, as shown in FIG. 11, a 1/4 circular cylindrical mirror 510 may be employed. In this case, the cylindrical mirror 510 has a function of directing light traveling in the + Z-axis direction in the + X-axis direction. For this reason, it is necessary to employ the light intensity distribution shaping member 1100 to which a function of directing light traveling in the −X axis direction inside the light intensity distribution shaping member to the + Z axis direction is added.

  For example, a prism shape is added to the surface of the light intensity distribution shaping member 1100 that faces the light incident surface 1100a. Thereby, the light traveling in the −X-axis direction can be reflected and directed in the + Z-axis direction using the difference in refractive index between the light intensity distribution shaping member 1100 and the air layer. Furthermore, by depositing a reflective film on the prism surface, it is possible to suppress the generation of light that is not reflected by the prism surface and transmitted, and to suppress light loss.

  In the second embodiment, the light intensity distribution shaping member 110 and the light intensity distribution shaping member 1100 are arranged in parallel to the light guide plate 811 or the light reflection sheet 15, but the present invention is not limited to this. As shown in FIG. 12, the light intensity distribution shaping member 1100 may be configured to form an arbitrary angle with the light guide plate 811 or the light reflection sheet 15. The same applies to the light intensity distribution shaping member 110.

  In this way, the light intensity distribution shaping member 1100 is arranged to be inclined with respect to the main plane (XY plane in FIG. 12) in the casing of the liquid crystal display device 2000. Thus, there is an advantage that it is easy to optimize the relation between the direction of the axis of the outgoing light 600 and the outgoing light 1000, the inclination angle of the prism surface, the cylindrical mirror 510 as the light traveling direction conversion member, and the light guide plate 811. is there. In addition, since the light source 6 and the light source 10 have a size, even when the light guide plate 811 and the light intensity distribution shaping member 1100 are remotely arranged, the light intensity distribution shaping member 1100 is tilted to end the liquid crystal display device 2000. The thickness of the portion (near the light incident surface of the light guide plate 811) can be suppressed.

  In each of the above-described embodiments, terms indicating the positional relationship between components or the shape of the components, such as “parallel” and “vertical”, may be used. Further, there are cases where expressions with terms such as “substantially” or “substantially” such as substantially square, approximately 90 degrees, and approximately parallel are used. These represent that a range that takes into account manufacturing tolerances and assembly variations is included. For example, “substantially −Z-axis direction” is also a term including manufacturing tolerances and assembly variations. For this reason, even if “abbreviation” is not described in the claims, it includes a range that takes into account manufacturing tolerances and assembly variations. In addition, when “substantially” is described in the claims, it indicates that a range in consideration of manufacturing tolerances, assembly variations, and the like is included.

  DESCRIPTION OF SYMBOLS 1 Liquid crystal optical element, 1a Display surface, 15 Light reflection sheet, 110,210,310,1100 Light intensity distribution shaping member, 110a, 1100a Light incident surface, 110b Light output surface, 1106a, 1106b, 1106c, 1106d, 1106e, 1106f Light incident end face, 1110a, 1110b, 1110c light incident face, 111 fine optical structure, 100, 120, 121a, 121b, 122 angular intensity distribution, 210b light exit face, 210c, 210d, 310c, 310d side face, 31, 32 optical sheet , 303 backlight device, 51 control unit, 52 liquid crystal display element driving unit, 53a, 53b light source driving unit, 55 liquid crystal display element control signal, 56a, 56b light source control signal, 500, 510 cylindrical mirror, 50 a reflective surface, 6 light sources, 6a, 6b, 6c, 6d, 6e, 6f laser element, 600 outgoing light, 600a, 600b, 600c, 600d, 600e, 600f outgoing light, 809 linear light, 810 illumination light, 811 Light guide plate, 811a light incident surface, 812 light diffuse reflection part, 812a diffuse reflection material, 10 light source, 10a, 10b, 10c LED element, 1000 emitted light, 800, 2000 liquid crystal display device.

Claims (5)

A first light source that emits a first light beam;
A second light source that emits a second light beam having a wider angular intensity distribution than the first light beam;
An angular intensity distribution shaping region, the angular intensity distribution of the first light ray is changed in the angular intensity distribution shaping region, and the first light ray and the second light ray are incident from a light incident surface and mixed to form a line; A light intensity distribution shaping member that emits in the form of shaped light, and the first light ray is incident with an inclination relative to a reference plane of the light intensity distribution shaping member and propagates while being reflected by the angular intensity distribution shaping region. ,
The light mixing unit in which the second light beam is incident substantially perpendicular to a reference plane of the light intensity distribution shaping member.   2. The light mixing unit according to claim 1, wherein the first light source has a plurality of light emitting portions and is arranged at an angle symmetrical to an optical axis of the linear light.   The light mixing unit according to claim 1, wherein the light incident surface has an optical structure that scatters the first light beam. The light mixing unit according to any one of claims 1 to 3,
A surface light source device further comprising a surface light-emitting light-guiding plate that receives the linear light emitted from the light mixing unit and emits the light as planar light.   The liquid crystal display device which has a surface light source device of any one of Claim 1 to 4.

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