JP2006313684A - Light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device capable of obtaining a desired planar light source. <P>SOLUTION: A plural kinds of light-emitting diodes 39 to 41 for irradiating white light on a liquid crystal display part 20 are constituted of light-emitting diode elements emitting a first emission light directed toward a reflector 33 correspondent to each out of the plurality of reflectors 33 and a second emission light expanding the irradiation light from the reflector 33 to which the first emission light is directed. For this, the emission light from the light-emitting diode lamp 37 is irradiated so as to spread from the reflector 33. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light source device suitable for use in, for example, a backlight illumination tool for a liquid crystal television.

  2. Description of the Related Art In recent years, liquid crystal displays have gained widespread use mainly for small and medium sized displays because they have advantages such as thinness and low power consumption compared to cathode ray tube (CRT) displays.

  As a light source device in such a liquid crystal display, in consideration of eliminating the adverse effect of mercury gas on the environment (human body), the deterioration of components due to ultraviolet light irradiation is prevented, and the power consumption cost due to the use of an inverter circuit From the viewpoint of reducing the amount of light and obtaining good color reproducibility, a light emitting diode (LED) element is employed instead of the cold cathode fluorescent tube in which mercury gas is enclosed.

  Conventionally, a light source device of this type has been proposed that includes an LED (light emitting diode lamp) incorporating a light emitting element and a reflector positioned around the LED (see, for example, Patent Document 1).

In such a light source device, the LED is turned on, and the illumination target (in front of the device) is irradiated after the lighting light is reflected by a reflector.
JP 2004-206947 A

  However, according to Patent Document 1, since it is used as a vehicular lamp, the emitted light from the light emitting element (light emitting diode element) is collected by the reflector, but the emitted light from the reflector is the irradiation surface of the illumination target. There is a problem that the desired planar light source cannot be obtained because it does not spread within a parallel virtual plane.

  Accordingly, an object of the present invention is to provide a light source device that can spread light emitted from a reflector in a virtual plane parallel to an irradiation surface to be illuminated, and thereby obtain a desired planar light source. .

  In order to achieve the above object, the present invention provides a plurality of reflectors that are arranged in parallel in at least one of the longitudinal and lateral directions in the same plane and that are open to the illumination target side, and are respectively accommodated in the plurality of reflectors. A light source device including a plurality of sets of light emitting diode lamps composed of a plurality of types of light emitting diode elements for irradiating an object with white light, wherein each of the plurality of types of light emitting diode elements is included in the plurality of reflectors. There is provided a light source device comprising a light emitting diode element that emits a first radiated light directed to a corresponding reflector and a second radiated light that spreads the emitted light from the reflector toward which the first radiated light is directed.

  According to the present invention, the light emitted from the reflector can be expanded in a virtual plane parallel to the irradiation surface of the illumination target, and a desired planar light source can be obtained.

[First embodiment]
FIG. 1 is a diagram for explaining a liquid crystal television provided with a light source device according to a first embodiment of the present invention. Fig.1 (a) is a front view, FIG.1 (b) is the sectional view on the AA line of Fig.1 (a). FIG. 2 is a front view for explaining the light source device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view for explaining the light source device according to the first embodiment of the present invention.
[Overall configuration of LCD television]

  1 (a) and 1 (b), a liquid crystal television (television) denoted by reference numeral 1 includes a main body portion 10 as an exterior body, a liquid crystal display portion 20 for displaying an image on the front surface of the main body portion 10, It is generally composed of a backlight unit 30 for illuminating the back surface (light incident surface) of the liquid crystal display unit 20.

  The main body 10 includes a housing 11 that houses various television components and a leg 12 that projects downward from the housing 11. The housing 11 has a through window 11A that opens forward, and is entirely formed of a substantially rectangular box made of a metal such as an aluminum alloy. The leg body 12 has a leg portion 12A and a seat portion 12B, is disposed below the housing 11, and is configured to hold the main body portion 10, the liquid crystal display portion 20, the backlight portion 30, and the like.

  The liquid crystal display unit 20 is composed of a transmissive liquid crystal panel having a liquid crystal display surface (light emitting surface) 20A, is disposed in front of the through window 11A, and is disposed on the front surface of a diffusion member 51 (described later) via a beef plate 52. It is installed. The illumination light from the backlight unit 30 incident on the light incident surface is converted into light corresponding to the image signal, and the converted light is emitted from the liquid crystal display surface 20A as transmitted light.

  The backlight unit 30 includes a light emitting diode lamp 37 for illuminating the liquid crystal display unit (illumination target) 20, and a diffusion member 51 for reducing luminance unevenness of illumination light emitted from the light emitting diode lamp 37. It is housed and held in the housing 11.

(Configuration of light-emitting diode lamp 37)
2 and 3, the light-emitting diode lamp 37 includes a plurality of element mounting boards 32 for mounting light-emitting diode elements and the like, a plurality of reflectors 33 as reflecting members, and white light on the liquid crystal display unit 20. A plurality of light emitting diode elements 39 to 41 for irradiating light, a heat sink 34 for dissipating heat generated by light emission of these light emitting diode elements 39 to 41, and further supplying power to the light emitting diode elements 39 to 41 The heat sink 34 is fixed to the housing 11 by being disposed in the rear region of the diffusing member 51.

<Configuration of element mounting substrate 32>
As shown in FIG. 3, the element mounting substrate 32 has a circuit pattern surface 32A parallel to the light incident surface of the liquid crystal display unit 20 on the element mounting side, arranged in parallel in the vertical and horizontal directions in the same plane, and It is fixed in the housing 11 via a heat sink 34. Among these, the element mounting boards 32 arranged in parallel in the horizontal direction are arranged close to (adjacent), while the element mounting boards 32 arranged in parallel in the vertical direction are arranged with a predetermined interval. The whole is formed of a flat rectangular aluminum base substrate or ceramic substrate. The element mounting substrate 32 can be another substrate such as a glass epoxy substrate. In this case, it is preferable to take heat dissipation measures such as disposing a heat conductive member such as a thermal pad on the back side of the element mounting substrate 32.

<Configuration of reflector 33>
The reflectors 33 are arranged in parallel in the vertical and horizontal directions as shown in FIG. 2, and are mounted on the circuit pattern surface 32A of the element mounting board 32 as shown in FIG. Since the reflector 33 has substantially the same configuration, only the configuration of one reflector 33 will be described. The reflector 33 has a reflective film made of aluminum or the like on its inner surface and is formed by a concave mirror having a cross-sectional arc shape that opens to the illumination target side. Has been. And it is comprised so that the emitted light from the light emitting diode elements 39-41 may be condensed and reflected toward the diffusion member 51.

<Configuration of light-emitting diode lamp 37>
As shown in FIG. 2, the light emitting diode lamps 37 are arranged in parallel in the vertical and horizontal directions and are mounted on the element mounting substrate 32. Since the light emitting diode lamp 37 has substantially the same configuration, only one light emitting diode lamp 37 will be described. The light emitting diode lamp 37 includes a red light emitting diode element 39, a green light emitting diode element 40, and a blue light emitting element that are juxtaposed in the horizontal direction. It consists of a diode element 41 and is connected to a power supply board via an element mounting board 32. The light emitting diode elements 39 to 41 are lateral emission type light emitting diode elements, and are mounted on the circuit pattern surface 32 </ b> A of the element mounting substrate 32. Each of the plurality of reflectors 33 is configured to radiate the first radiated light directed toward the corresponding reflector 33 and the second radiated light that spreads the emitted light from the reflector 33 toward which the first radiated light is directed. Yes.

<Configuration of heat sink 34>
The heat sink 34 is made of a heat conductive member such as a copper alloy or an aluminum alloy, and is disposed on the side opposite to the illumination target of the element mounting substrate 32. Since the heat sink 34 has substantially the same configuration, the configuration of one heat sink 34 will be described. As shown in FIG. 3, the heat sink 34 includes a receiving portion 34 </ b> A that is in close contact with the end surface on the side opposite to the illumination target of the element mounting substrate 32. The holding portion 34B is connected to the receiving portion 34A, and is fixed to the back surface portion of the housing 11. The heat generated from the light-emitting diode lamp 37 is dissipated to the surroundings, and the heat is conducted to the housing 11.

(Configuration of diffusion member 51)
The diffusing member 51 is disposed in the front region of the backlight unit 30 and is attached to the opening periphery of the through window 11A via the bracket 21. It is formed of a heat resistant member. Then, the illumination light emitted from the light emitting diode lamp 37 is diffused inside, and the luminance unevenness is reduced as described above. As the material of the diffusing member 51, other materials may be used as long as they are light transmissive and are not deformed or altered by the heat generated by the light emitting diode lamp 37.

[Operation of Light Emitting Diode Lamp 37]
When a voltage is applied to the light emitting diode lamp 37 from the power supply substrate, each of the light emitting diode elements 39 to 41 emits light in the light emitting layer, and a part of each of the emitted light (first emitted light) is reflected by the reflector 33. The light is emitted from the reflector 33, and the other radiated light (second radiated light) is emitted so as to spread from the reflector 33. Therefore, it is possible to obtain a planar light source having uniform brightness and good color mixing in the light incident surface and the virtual surface of the liquid crystal display unit 20. Then, the radiated light from the light emitting diode lamp 37 enters the diffusing member 51, and the incident light irradiates the liquid crystal display unit 20 as white light while being diffused in the diffusing member 51.

[Effect of the first embodiment]
According to the first embodiment described above, the following effects can be obtained.
(1) The first radiation emitted from the light emitting diode elements 39 to 41 of the light emitting diode lamp 37 is reflected by the reflector 33 and emitted from the reflector 33, and the second radiation is emitted so as to spread from the reflector 33. Thereby, a planar light source of white light can be obtained reliably in a virtual plane parallel to the light incident surface of the liquid crystal display unit 20.

(2) Since the second radiated light radiated from the light emitting diode elements 39 to 41 of the light emitting diode lamp 37 is emitted so as to spread from the respective reflectors 33, a space conventionally required for obtaining a planar light source is required. Therefore, the dimension between the liquid crystal display unit 20 and the light-emitting diode lamp 37 can be set to a small dimension, and the entire apparatus can be reduced in thickness.

(3) Since the overall vertical and horizontal dimensions of the light emitting diode lamp 37 can be made to correspond to the vertical and horizontal dimensions of the illumination target, even if the design of the illumination target is changed, the light emitting diode lamp is changed according to the design change. It is not necessary to manufacture all 37, and the manufacturing cost can be reduced.

(4) Since the light emitting diode elements 39 to 41 used for the illumination of the liquid crystal display unit (illumination target) 20 are respectively accommodated in the corresponding reflectors 33, some of the light emitting diode elements 37 to 41 in the light emitting diode lamp 37. If the LED fails and does not function, the light-emitting diode lamp may be replaced with the reflector 33 at the time of repair / inspection, and the replacement cost can be reduced.

[Second Embodiment]
FIG. 4 is a cross-sectional view for explaining the light source device according to the second embodiment of the present invention. 4, the same members as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the light source device shown in the second embodiment is provided with an optical lens 62 (only one shown) that collects the emitted light from the light emitting diode lamp 37 (only one shown). There is a feature.

  For this reason, the optical lens 62 is crowned (mounted) on the illumination target side end of the reflector 33, and is configured to collect the radiation light from the light emitting diode lamp 37. The illumination object side end surface of the optical lens 62 is formed of a plurality of light diffusion surfaces 62A for diffusing the radiated light from the corresponding light emitting diode lamps 37, respectively.

[Effect of the second embodiment]
According to the second embodiment described above, the following effects can be obtained in addition to the effects of the first embodiment.

  The radiated light emitted from the light emitting diode elements 39 to 41 of the light emitting diode lamp 37 and the reflected light reflected by the reflector 33 are collected by the optical lens 62 and diffused by the light diffusion surface 62 </ b> A. Is emitted. Thereby, a planar light source of white light can be obtained reliably in a virtual plane parallel to the light incident surface of the liquid crystal display unit 20.

[Third embodiment]
FIG. 5 is a front view for explaining the light source device according to the third embodiment of the present invention. 5, the same members as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the light source device shown in the third embodiment has a plurality of types of light emitting diode elements 72 to 75 (red light emitting diode elements 72, green light emitting diode elements 73 and 74, blue light emitting elements) arranged in parallel in the vertical direction. A plurality of sets of light emitting diode lamps (groups of light emitting diode lamps) 76 having a diode element 75) and a plurality of reflectors arranged in parallel in the lateral direction (a direction perpendicular to the parallel direction of the plurality of types of light emitting diode elements 72 to 75). 77 is characterized.

  Therefore, a plurality of sets of light emitting diode lamps (a plurality of sets of light emitting diode lamp groups) 76 corresponding to each of the plurality of reflectors 77 are accommodated. Each group of the light emitting diode lamp groups 76 includes five light emitting diode lamps 76A, and these light emitting diode lamps 76A are arranged in parallel in the same direction as the parallel direction of the plurality of types of light emitting diode elements 72 to 75.

[Effect of the third embodiment]
According to the third embodiment described above, the following effects are obtained in addition to the effects of the first embodiment.

  Since the light emitting diode lamps 76A having a plurality of kinds of light emitting diode elements 72 to 75 arranged in parallel in the vertical direction are arranged in parallel in the vertical direction in the plurality of reflectors 77 arranged in parallel in the horizontal direction, the light emitting diodes are arranged in the horizontal direction. The lamp group 76 can be densely arranged.

[Fourth embodiment]
FIG. 6 is a front view shown for explaining the light source device according to the third embodiment of the present invention. 6, the same members as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the light source device shown in the fourth embodiment includes a plurality of types of light emitting diode elements 82 to 85 (red light emitting diode element 82, green light emitting diode elements 83 and 84, blue light emitting) arranged in parallel in the horizontal direction. A plurality of sets of light emitting diode lamps (groups of light emitting diode lamps) 86 having a diode element 85) and a plurality of reflectors arranged in parallel in the lateral direction (the same direction as the parallel direction of the plurality of types of light emitting diode elements 82 to 85). 87 is characteristic.

  Therefore, a plurality of sets of light-emitting diode lamps (a plurality of sets of light-emitting diode lamp groups) 86 corresponding to each of the plurality of reflectors 87 are accommodated. Each group of light emitting diode lamp groups 86 includes nine light emitting diode lamps 86A, and these light emitting diode lamps 86A are arranged in parallel in a direction perpendicular to the parallel direction of the plurality of types of light emitting diode elements 82 to 85.

[Effect of the fourth embodiment]
According to the fourth embodiment described above, the following effects can be obtained in addition to the effects of the first embodiment.

  Since a plurality of light-emitting diode lamps 86A having a plurality of types of light-emitting diode elements 82 to 85 that are also arranged in parallel in the horizontal direction are arranged in parallel in the vertical direction in the plurality of reflectors 87 that are arranged in parallel in the horizontal direction. The light emitting diode lamps 86A can be densely arranged.

(A) And (b) is the front view and sectional drawing shown in order to demonstrate the liquid crystal television provided with the light source device which concerns on the 1st Embodiment of this invention. The front view shown in order to demonstrate the light source device which concerns on the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the light source device which concerns on the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the light source device which concerns on the 2nd Embodiment of this invention. The front view shown in order to demonstrate the light source device which concerns on the 3rd Embodiment of this invention. The front view shown in order to demonstrate the light source device which concerns on the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal television, 10 ... Main-body part, 11 ... Housing | casing, 11A ... Through-hole window, 12 ... Leg, 12A ... Leg part, 12B ... Seat part, 20 ... Liquid crystal display part, 20A ... Liquid crystal display surface, 21 ... Bracket 30 ... Backlight part, 32 ... Element mounting substrate, 32A ... Circuit pattern surface, 33, 77, 87 ... Reflector, 34 ... Heat sink, 34A ... Receiving part, 34B ... Holding part, 37, 76A, 86A ... Light emitting diode lamp , 39, 72, 82 ... red light emitting diode element, 40, 73, 74, 83, 84 ... green light emitting diode element, 41, 75, 85 ... blue light emitting diode element, 51 ... diffusion member, 52 ... buff plate, 62 ... Optical lens, 62A ... Light diffusion surface, 76, 86 ... Light emitting diode lamp group

Claims (6)

A plurality of reflectors that are arranged in parallel in at least one of the vertical and horizontal directions in the same plane and open to the illumination target side;
A light source device comprising a plurality of sets of light emitting diode lamps, each of which is housed in each of the plurality of reflectors and includes a plurality of types of light emitting diode elements for irradiating an illumination target with white light,
The plurality of types of light emitting diode elements radiate a first radiated light directed to a corresponding reflector among the plurality of reflectors and a second radiated light that spreads the emitted light from the reflector toward which the first radiated light is directed. A light source device comprising a light emitting diode element.   2. The light source according to claim 1, further comprising a plurality of optical lenses that are respectively crowned on the illumination target side end portions of the plurality of reflectors and collect the radiated light from the plurality of sets of light-emitting diode lamps respectively corresponding to the crowns. apparatus.   3. The light source device according to claim 2, wherein the illumination target side end surfaces of the plurality of optical lenses are formed of a plurality of light diffusion surfaces for diffusing emitted light from the plurality of sets of light emitting diode lamps to which the illumination lenses correspond respectively. .   The light source device according to claim 1, wherein the plurality of reflectors are arranged in parallel in the same direction as a parallel direction of the plurality of types of light emitting diode elements.   The light source device according to claim 1, wherein the plurality of reflectors are arranged in parallel in a direction perpendicular to a parallel direction of the plurality of types of light emitting diode elements.   6. The light source device according to claim 1, wherein the plurality of types of light-emitting diode elements are each composed of one red light-emitting diode element and one blue light-emitting diode element and two green light-emitting diode elements.

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