JP2010009787A - Illumination unit, and liquid crystal display therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination unit which has a heat radiation structure capable of extending the life of light emitting diodes and which enables a light source unit with light emitting diodes to be replaced easily. <P>SOLUTION: A tubular accommodation section 30 formed with one end surface 22c of a light guide 22, a frame 23 and a heat radiation plate 24 is configured such that the light source unit 21 is insertable/removable in a first direction. The light source includes: light emitting diodes 41 each having a light emission surface which is substantially parallel to a mounting surface; a film substrate 42 on which the plurality of light emitting diodes are arranged in the first direction and mounted; a heat radiation member 43 having a support portion 43A which supports the film substrate and a reflection portion 43B which extends from the support portion in a second direction perpendicular to the first direction; and an adhesive tape 44 which adheres the film substrate to the support portion and includes heat radiation properties. In a state in which the light source unit is inserted in the accommodation section, the light emission surface of the light-emitting diode is opposed to one end surface of the light guide, and the reflection portion of the heat radiation member is put in contact with the heat radiation plate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an illumination unit and a liquid crystal display device including the illumination unit, and more particularly to an illumination unit including a light emitting diode (LED) as a light source and a liquid crystal display device including the illumination unit.

  Liquid crystal display devices are utilized in various fields as display devices for OA equipment such as personal computers and televisions, taking advantage of features such as light weight, thinness, and low power consumption. In recent years, liquid crystal display devices are also used as mobile terminal devices such as mobile phones, display devices such as car navigation devices and game machines.

  As such a liquid crystal display device, a reflection type that selectively reflects external light to display an image, a transmission type that selectively transmits backlight light to display an image, and a reflection type and transmission type A module such as a transflective module that has both functions of a mold has been developed.

  Among these, the transmissive liquid crystal display device includes a transmissive liquid crystal display panel and an illumination unit (that is, a backlight) disposed on the back side of the liquid crystal display panel. In recent years, as a lighting unit mounted on such a liquid crystal display device, a light emitting diode applied as a light source has been put into practical use.

  For example, according to Patent Document 1, a plurality of semiconductor light emitting devices (LEDs or light emitting diodes) having a light emitting surface that is substantially perpendicular to the mounting surface are mounted in a row on one surface of a film substrate, and light emission of the semiconductor light emitting device is performed. A backlight device is disclosed that is housed in a metal frame with one surface of a film substrate attached to the surface of the light guide plate so that the surface is in close contact with the light incident surface of the light guide plate.

In particular, according to this Patent Document 1, in order to release heat generated in the semiconductor light emitting element to the metal frame, a heat radiating metal thin film is provided on almost the entire other surface of the film substrate where the semiconductor light emitting element is not mounted. The metal thin film is pressed by the metal frame. Further, according to Patent Document 1, a so-called side view type LED is used as a semiconductor light emitting element, and the film substrate is firmly bonded over a wide area of the light guide plate.
JP 2003-76287 A

  The light emitting diode has a characteristic of generating heat during operation and has a characteristic of being easily deteriorated in a high temperature environment. For this reason, in order to extend the life of the light emitting diode, it is desired to improve the heat dissipation efficiency and drive in a low temperature environment.

  In addition, when a light emitting diode deteriorates, it is desired that it can be easily replaced. As in Patent Document 1, in the configuration in which the film substrate on which the LED is mounted is bonded to the light guide plate, it is necessary to disassemble the backlight device and peel the film substrate from the light guide plate. More complicated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to have a heat dissipation structure capable of extending the life of a light emitting diode and to easily replace a light source unit including the light emitting diode. An object of the present invention is to provide an illumination unit and a liquid crystal display device including the illumination unit.

A lighting unit according to an aspect of the present invention comprises:
A light guide plate;
A frame that holds the light guide plate and is spaced from one end surface of the light guide plate;
A heat radiating plate that forms a cylindrical accommodating portion together with one end surface of the light guide plate and the frame;
A light source unit housed in the housing portion,
The accommodating portion is configured to be able to insert and remove the light source unit in the first direction,
The light source unit includes: a light emitting diode whose light emitting surface is substantially parallel to a mounting surface; a film substrate on which a plurality of the light emitting diodes are mounted side by side in the first direction; a support unit that supports the film substrate; A heat radiating member having a reflecting portion extending in a second direction orthogonal to the first direction from the supporting portion; and an adhesive tape that adheres the film substrate to the supporting portion and has a heat radiating property. The light emitting surface of the light emitting diode faces the one end surface of the light guide plate in a state of being inserted into the portion, and the reflective portion of the heat radiating member and the heat radiating plate are in contact with each other.

A liquid crystal display device according to an aspect of the present invention includes:
A liquid crystal display panel holding a liquid crystal layer between a pair of substrates;
An illumination unit that is disposed on the liquid crystal display panel and illuminates the liquid crystal display panel,
The lighting unit is:
A light guide plate;
A frame that holds the liquid crystal display panel and the light guide plate and is spaced from one end surface of the light guide plate;
A heat radiating plate that forms a cylindrical accommodating portion together with one end surface of the light guide plate and the frame;
A light source unit housed in the housing portion,
The accommodating portion is configured to be able to insert and remove the light source unit in the first direction,
The light source unit includes: a light emitting diode having a light emitting surface that is substantially parallel to a mounting surface; a film substrate on which the plurality of light emitting diodes are mounted side by side in the first direction; a support unit that supports the film substrate; A heat radiating member having a reflecting portion extending in a second direction orthogonal to the first direction from the supporting portion; and an adhesive tape that adheres the film substrate to the supporting portion and has a heat radiating property. The light emitting surface of the light emitting diode faces the one end surface of the light guide plate in a state of being inserted into the portion, and the reflective portion of the heat radiating member and the heat radiating plate are in contact with each other.

  According to the present invention, there is provided an illumination unit having a heat dissipation structure capable of extending the life of a light-emitting diode, and capable of easily replacing a light source unit including the light-emitting diode, and a liquid crystal display device including the illumination unit. be able to.

  That is, the light source unit includes a plurality of light emitting diodes mounted side by side in the first direction. The housing portion surrounded by the light guide plate, the frame, and the heat radiating plate is configured so that the light source unit can be inserted and removed along the first direction. For this reason, it becomes possible to replace | exchange a light source unit easily by extracting a light source unit from an accommodating part.

  In the light source unit, the film substrate on which a plurality of light emitting diodes as heat sources are mounted is bonded to the support portion of the heat radiating member with a heat radiating adhesive tape. Thus, since the film substrate closer to the heat source is bonded to the heat dissipation member, the heat generated in the light emitting diode is directly transmitted from the film substrate to the heat dissipation member via the adhesive tape without passing through a heat insulating material such as air, Heat dissipation efficiency can be improved.

  Furthermore, in a state where the light source unit is inserted into the housing portion, the heat radiating member is in contact with the heat radiating plate. For this reason, the heat generated in the light emitting diode can be released from the heat radiating member of the light source unit to the heat radiating plate.

  Thereby, the light emitting diode can be driven in a low temperature environment, and the life of the light emitting diode can be extended.

  Hereinafter, an illumination unit and a liquid crystal display device according to an embodiment of the present invention will be described with reference to the drawings. Here, a liquid crystal display device having a transmissive display function for selectively transmitting backlight light from a backlight unit, which is an illumination unit, and displaying an image will be described.

  That is, as shown in FIG. 1, the liquid crystal display device 1 includes a transmissive liquid crystal display panel 2 having a substantially rectangular flat plate shape, and a backlight unit 15 that illuminates the liquid crystal display panel 2. The liquid crystal display panel 2 is configured by holding a liquid crystal layer between a pair of substrates. That is, the liquid crystal display panel 2 includes a substantially rectangular array substrate 3 and a counter substrate 4, and a liquid crystal layer 5 sealed between the array substrate 3 and the counter substrate 4. The array substrate 3 and the counter substrate 4 are bonded to each other through a sealing material (not shown).

  The liquid crystal display panel 2 includes a substantially rectangular active area 6 for displaying an image on the inner side surrounded by a sealing material. The active area 6 is composed of a plurality of pixels PX arranged in a matrix.

  In the active area 6, the array substrate 3 includes a plurality of scanning lines Y (1, 2,...), A plurality of signal lines X (1, 2,...), A switching element 7 disposed in each pixel PX, and each pixel PX. The pixel electrode 8 connected to the switching element 7 is provided. The pixel electrode 8 is formed of a light-transmitting conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

  Each scanning line Y extends along the row direction of the pixel PX. Each signal line X extends along the column direction of the pixels PX so as to intersect with each scanning line Y via an insulating layer. Each switching element 7 is disposed in a region including an intersection of the scanning line Y and the signal line X.

  The switching element 7 is composed of, for example, a thin film transistor (TFT) having a semiconductor layer formed of amorphous silicon, polysilicon, or the like. The gate electrode 7G of the switching element 7 is electrically connected to the corresponding scanning line Y (or formed integrally with the scanning line). The source electrode 7S of the switching element 7 is electrically connected to the corresponding signal line X (or formed integrally with the signal line). The drain electrode 7D of the switching element 7 is electrically connected to the pixel electrode 8 of the corresponding pixel PX.

  The common electrode 9 for applying a voltage to the liquid crystal layer 5 due to a potential difference with the pixel electrode 8 may be provided on the array substrate 3 or on the counter substrate 4. That is, in the horizontal electric field mode mainly using the horizontal electric field (electric field substantially parallel to the main surface of the substrate), the array substrate 3 has the common electrode 9 that is electrically insulated from the pixel electrode 8 and opposed to the pixel electrode 8. I have. In the vertical electric field mode mainly using the vertical electric field (electric field substantially perpendicular to the main surface of the substrate), the counter substrate 4 includes a common electrode 9 that faces the pixel electrode 8 with the liquid crystal layer 5 interposed therebetween. Similar to the pixel electrode 8, the common electrode 9 is formed of a light-transmitting conductive material.

  The surfaces of the array substrate 3 and the counter substrate 4 that are in contact with the liquid crystal layer 5 are each covered with an alignment film. The array substrate 3 and the counter substrate 4 are bonded to each other with the alignment films facing each other via a spacer (not shown) (for example, a columnar spacer formed integrally with one substrate). At this time, a predetermined gap is formed between the array substrate 3 and the counter substrate 4 by a spacer. The liquid crystal layer 5 is formed of a liquid crystal composition sealed in the gap between the array substrate 3 and the counter substrate 4.

  In the liquid crystal display panel 2, optical elements OD1 and OD2 are provided on the outer surface of the array substrate 3 and the outer surface of the counter substrate 4, respectively. These optical elements OD1 and OD2 include a polarizing plate whose polarization direction is set in accordance with the characteristics of the liquid crystal layer 5. Further, the optical elements OD1 and OD2 may include a retardation plate as necessary.

  In the color display type liquid crystal display device, the liquid crystal display panel 2 includes a plurality of types of pixels in the active area 6, for example, a red pixel that displays red (R), a green pixel that displays green (G), and a blue (B). Has a blue pixel. That is, the red pixel includes a red color filter that transmits light having a red main wavelength. The green pixel includes a green color filter that transmits light having a green dominant wavelength. The blue pixel includes a blue color filter that transmits light having a blue main wavelength. These color filters are arranged on the main surface of the array substrate 3 or the counter substrate 4.

  The liquid crystal display device 1 includes a bezel cover 11 having a rectangular frame shape. The bezel cover 11 includes a rectangular window portion 11A that exposes the active area 6 of the liquid crystal display panel 2, and a rectangular frame-shaped main body portion 11B that defines the window portion 11A. The liquid crystal display panel 2 configured as described above is sandwiched between the backlight unit 15 and the bezel cover 11. At this time, the backlight unit 15 is arranged with the surface thereof facing the back side of the liquid crystal display panel 2 (that is, the array substrate side), and illuminates the liquid crystal display panel 2 from the back side.

  As shown in FIG. 2, the backlight unit 15 includes a light source unit 21, a light guide plate 22, a frame 23, a heat radiating plate 24, a back cover 25, an optical sheet 26, and the like.

  The light guide plate 22 has a function of guiding emitted light from the light source unit 21 toward the liquid crystal display panel 2. The light guide plate 22 is made of a light-transmissive resin material such as acrylic resin or polycarbonate resin. The light guide plate 22 includes a wedge-type plate having a thin portion at one end and a thick portion at the other end opposed to the thin portion, and a flat plate type having a substantially uniform thickness over the whole. However, in this embodiment, a rectangular flat plate type is adopted.

  The light guide plate 22 includes a rectangular first main plane 22a facing the liquid crystal display panel 2, a rectangular second main plane 22b facing the first main plane 22a, and the first main plane 22a. And four rectangular end faces connecting the second main plane 22b. The one end surface 22 c functions as an incident surface facing the light source unit 21. Further, the first main plane 22 a functions as an emission surface that emits light toward the liquid crystal display panel 2.

  The frame 23 is mainly configured to hold the light guide plate 22. The frame 23 is also configured to hold the liquid crystal display panel 2. Such a frame 23 is made of a resin material. The frame 23 is separated from the one end surface 22 c of the light guide plate 22. The bezel cover 11 is fixed to the frame 23 by a method such as caulking or screwing in a state where the liquid crystal display panel 2 is sandwiched between the bezel cover 11 and the frame 23.

  The heat radiating plate 24 closes the space between the one end surface 22c of the light guide plate 22 and the frame 23, and extends in the normal direction of the paper surface in FIG. A cylindrical accommodating portion 30 is formed. The heat radiating plate 24 is made of a heat radiating material such as stainless steel (SUS) or aluminum (Al). Further, the heat radiating plate 24 is fixed to the frame 23 by a method such as caulking or screwing.

  The accommodating portion 30 corresponds to a space that can accommodate the light source unit 21 described in detail later, and extends in the extending direction of the light source unit 21.

  The back cover 25 is generally formed in a box shape and can store the light guide plate 22 and the like together with the frame 23 and the like.

  As the optical sheet 26, an optical sheet 26 </ b> A disposed between the liquid crystal display panel 2 and the first main plane 22 a of the light guide plate 22, and a back cover 25 and the second main plane 22 b of the light guide plate 22. An arranged optical sheet 26B is provided. The optical sheet 26A is, for example, a light condensing sheet, a diffusion sheet, a sheet having a plurality of optical functions, and the like, and imparts predetermined optical characteristics to the light emitted from the light guide plate 22 to the liquid crystal display panel 2. Lead. The optical sheet 26 </ b> B is a reflection sheet, and reflects the light leaking from the second main plane 22 b of the light guide plate 22 toward the light guide plate 22 again. These optical sheets 26 are formed in a substantially rectangular shape having substantially the same size as the first main plane 22 a and the second main plane 22 b of the light guide plate 22.

  As shown in FIGS. 3 and 4, the light source unit 21 has a shape extending in the first direction D1, and is a light emitting diode (LED) 41, a film substrate 42, a heat radiating member 43, and an adhesive tape 44, which are point light sources. And so on.

  The light emitting diode 41 is a semiconductor light emitting element having a light emitting surface 41 </ b> E that is substantially parallel to a mounting surface mounted on the film substrate 42. The film substrate 42 is formed in a strip shape extending in the first direction D1 (that is, a substantially rectangular shape having a long side along the first direction D1). The plurality of light emitting diodes 41 are mounted on the film substrate 42 side by side in the first direction D1. In the example shown in FIG. 3 and the like, the plurality of light emitting diodes 41 are arranged in a line along the first direction D1, but may be arranged in a plurality of lines.

  The heat radiating member 43 includes a support portion 43A that supports the film substrate 42, and a reflection portion 43B that extends from the support portion 43A in a second direction D2 orthogonal to the first direction D1. The support portion 43A and the reflection portion 43B are integrally formed so as to have a substantially L-shaped cross section.

  That is, the support portion 43A has a substantially rectangular shape having long sides along the first direction D1 and short sides along the third direction D3 orthogonal to the first direction D1 and the second direction D2. . The length of the short side along the third direction D3 of the support portion 43A is equal to or greater than the width of the film substrate 42 (that is, the length of the short side of the rectangle). The reflection portion 43B has a substantially rectangular shape having long sides along the first direction D1 and short sides along the second direction D2. One long side of the support part 43A and one long side of the reflection part 43B are connected. In the example shown here, the other long side of the support portion 43A is similarly connected to the other reflection portion 43C, and the heat radiating member 43 is formed to have a substantially U-shaped cross section.

  Further, the heat radiating member 43 includes an insertion portion 43E on one end side along the first direction D1. Further, the heat dissipation member 43 includes a knob 43F on the other end side along the first direction D1. The knob portion 43F is formed on a surface orthogonal to the support portion 43A and the reflection portions 43B and 43C. For example, a screw hole is provided in the knob 43F.

  Such a heat radiating member 43 is formed of a metal material having heat radiating properties such as stainless steel (SUS) or aluminum (Al). The reflecting portions 43B and 43C are formed so that the surface surrounding the light emitting diode 41 has light reflectivity, and reflects a part of the light emitted from the light emitting diode 41.

  The adhesive tape 44 bonds the film substrate 42 on which the plurality of light emitting diodes 41 are mounted to the support portion 43A. At this time, the light emitting surface 41E of the light emitting diode 41 faces the second direction D2. The adhesive tape 44 is made of a material having heat dissipation properties.

  The accommodating part 30 mentioned above is comprised so that the light source unit 21 of such a structure can be inserted or extracted in the extension direction (namely, D1). That is, the accommodating part 30 has a guide that allows the light source unit 21 to be inserted along the extending direction D1. Such a guide is provided on at least one of the light guide plate 22, the frame 23, and the heat radiating plate 24 that constitute the housing portion 30. Moreover, this accommodating part 30 has a recess into which the insertion part 43E of the light source unit 21 is inserted.

  Thus, the light source unit 21 inserted and accommodated in the accommodating portion 30 is positioned at a predetermined position by the guide and the recess. Further, in a state where the light source unit 21 is inserted into the housing portion 30, the knob portion 43 </ b> F of the heat radiating member 43 is screwed to the frame 23 as shown in FIG. 5. That is, a light source unit 21 is fixed to the frame 23 in a state where the light source unit 21 is positioned in the housing portion 30 by inserting a screw from a screw hole formed in the knob portion 43F and screwing the screw into the frame 23.

  Thus, in the state where the light source unit 21 is inserted into the housing portion 30, the light emitting surface 41E of the light emitting diode 41 faces the one end surface 22c of the light guide plate 22 and the heat radiating member 43 of the heat radiating member 43, as shown in FIG. The reflecting portion 43B is in contact with the heat sink 24. At this time, the support portion 43 </ b> A and the reflection portion 43 </ b> C of the heat dissipation member 43 are in contact with the frame 23.

  At this time, the light emitting surface 41E of the light emitting diode 41 is preferably separated from the one end surface 22c of the light guide plate 22. In other words, since the light emitting diode 41 is a heat generation source, if it is in contact with the light guide plate 22, there is a possibility that problems such as deformation of the light guide plate 22 occur due to the influence of the heat. In this embodiment, since the light source unit 21 is positioned in a state where the light source unit 21 is inserted into the housing portion 30, it is not necessary to position the light emitting diode 41 and the light guide plate 22 in contact with each other.

  According to such a configuration, in the light source unit 21, the film substrate 42 on which the plurality of light emitting diodes 41 that are heat sources are mounted is bonded to the heat radiating member 43 with the heat radiating adhesive tape 44. Heat generated by the diode 41 can be released from the film substrate 42 to the heat radiating member 43 via the adhesive tape 44. In particular, since the film substrate 42 is bonded to the support portion 43A without air functioning as a heat insulating material, the heat from the light emitting diode 41 can be directly released from the film substrate 42 to the heat radiating member 43. Efficiency can be improved.

  Further, the heat radiating member 43 is in contact with the heat radiating plate 24 in a state where the light source unit 21 is inserted into the housing portion 30. For this reason, the heat generated in the light emitting diode 41 can be further released from the heat radiating member 43 of the light source unit 21 to the heat radiating plate 24. Thus, by adding the heat radiating plate 24 to the heat radiating path, the heat capacity is increased and the heat radiating efficiency can be further improved as compared with the case where only the heat radiating member 43 is provided. Furthermore, since the heat sink 24 is exposed to the outside air, it is possible to further improve the heat dissipation efficiency.

  Therefore, the light emitting diode 41 can be driven in a relatively low temperature environment, and the life of the light emitting diode 41 can be extended.

  Further, when it is necessary to replace the light source unit 21 such as when the light emitting diode 41 is deteriorated, the light source unit 21 picks up the knob 43F of the heat radiating member 43 as shown in FIG. It is possible to extract the liquid crystal display device 1 from the storage unit 30 along the direction D1 in the side direction (side extraction method). As a result, the light source unit 21 can be easily replaced in units.

  In a state where the light source unit 21 is inserted into the housing part 30, it is desirable that the reflection part 43B of the heat dissipation member 43 and the heat dissipation plate 24 are screwed. For example, as shown in FIG. 6, the heat radiating member 43 and the heat radiating plate 24 are fixed by screwing from the back side of the liquid crystal display device 1 (two screws in the example shown in FIG. 6). It becomes possible to improve both adhesiveness. Thereby, the heat dissipation from the heat radiating member 43 to the heat radiating plate 24 can be further improved.

  The adhesive tape 44 applied in this embodiment is desirably formed so that its width (that is, the length along the third direction D3) is equal to or greater than the width of the film substrate 42.

  That is, when the width of the adhesive tape 44 is equal to the film substrate 42 (3 mm) and when the width of the adhesive tape 44 is smaller than the width of the film substrate 42 (1 mm), the temperature rise value of the light emitting diode 41 is changed. Compared. FIG. 7 shows a comparison result of temperature rise values for each tape width.

  Here, the difference between the temperature of the light-emitting diode 41 before driving and the temperature of the light-emitting diode 41 after a stable passage of 2 hours after supplying a predetermined amount of current to the light-emitting diode 41 is defined as a temperature rise value.

  When the width of the adhesive tape 44 is 1 mm, the temperature rise value is 34.9 ° C. when a current of 75 mA is supplied to the light emitting diode 41, and the temperature rise value is when the current of 150 mA is supplied to the light emitting diode 41. It was 79.6 ° C.

  On the other hand, when the width of the adhesive tape 44 is 3 mm, the temperature rise value is 22.8 ° C. when a current of 75 mA is supplied to the light emitting diode 41, and a current of 150 mA is supplied to the light emitting diode 41. Sometimes the temperature rise was 54.9 ° C.

  As described above, when the width of the adhesive tape 44 is smaller than the width of the film substrate 42, the heat path escaping from the film substrate 42 to the heat radiating member 43 is reduced, and the film is not provided in the portion where the adhesive tape 44 is not interposed. Since an air layer is interposed between the substrate 42 and the heat dissipation member 43 for heat insulation, a sufficient heat dissipation effect cannot be obtained and the temperature of the light emitting diode 41 is increased.

  Therefore, it is desirable to apply the adhesive tape 44 whose width is equal to or greater than the width of the film substrate 42. Thereby, the film substrate 42 can adhere | attach the whole surface of the surface on the opposite side to the surface in which the light emitting diode 41 was mounted to the heat radiating member 43. FIG. Therefore, it is possible to ensure a sufficient heat path without an air layer interposed between the film substrate 42 and the heat dissipation member 43.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  The transmissive liquid crystal display panel described in the above-described embodiment has a transmissive display function that selectively transmits illumination light from the backlight unit 15 in at least a part of the active area 6. Any configuration may be used, and a transflective liquid crystal display panel in which each pixel has a reflective portion and a transmissive portion is also included.

  In the embodiment described above, in particular, in the example shown in FIG. 2, the heat radiating plate 24 is fixed on the outside of the frame 23 by a technique such as caulking or screwing, but as shown in FIG. It may be fixed inside the frame 23 by a technique such as screwing. According to such a configuration, in the state in which the light source unit 21 is inserted into the accommodating portion 30, not only the reflecting portion 43B but also the support portion 43A of the heat radiating member 43 comes into contact with the heat radiating plate 24. Therefore, the example shown in FIG. As described above, the heat dissipation efficiency can be further improved as compared with the example in which the resin frame 23 and the support portion 43A are in contact with each other.

FIG. 1 is an exploded perspective view schematically showing the structure of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a structure including the light source unit of the backlight unit in the liquid crystal display device shown in FIG. FIG. 3 is a perspective view schematically showing the structure of the light source unit shown in FIG. FIG. 4 is a cross-sectional view schematically showing the structure when the light source unit shown in FIG. 3 is cut along line AA. FIG. 5 is a diagram for explaining a situation in which the light source unit is inserted and removed from the side in the liquid crystal display device shown in FIG. FIG. 6 is a diagram schematically showing the structure of the back side of the liquid crystal display device. FIG. 7 is a diagram showing a comparison result of temperature rise values of the light emitting diodes depending on the width of the adhesive tape. FIG. 8 is a cross-sectional view schematically showing another structure including the light source unit of the backlight unit in the liquid crystal display device shown in FIG.

Explanation of symbols

PX: Pixel 1 ... Liquid crystal display device 2 ... Liquid crystal display panel 3 ... Array substrate 4 ... Counter substrate 5 ... Liquid crystal layer 15 ... Backlight unit (illumination unit)
DESCRIPTION OF SYMBOLS 21 ... Light source unit 22 ... Light guide plate 23 ... Frame 24 ... Heat sink 25 ... Back cover 26 ... Optical sheet 30 ... Storage part 41 ... Light emitting diode 41E ... Light emitting surface 42 ... Film substrate 43 ... Heat radiating member 43A ... Support part 43B ... Reflection Part 43E ... Plug part 43F ... Pick part 44 ... Adhesive tape

Claims (7)

A light guide plate;
A frame that holds the light guide plate and is spaced from one end surface of the light guide plate;
A heat radiating plate that forms a cylindrical accommodating portion together with one end surface of the light guide plate and the frame;
A light source unit housed in the housing portion,
The accommodating portion is configured to be able to insert and remove the light source unit in the first direction,
The light source unit includes: a light emitting diode whose light emitting surface is substantially parallel to a mounting surface; a film substrate on which a plurality of the light emitting diodes are mounted side by side in the first direction; a support unit that supports the film substrate; A heat radiating member having a reflecting portion extending in a second direction orthogonal to the first direction from the supporting portion; and an adhesive tape that adheres the film substrate to the supporting portion and has a heat radiating property. The lighting unit, wherein the light emitting surface of the light emitting diode faces the one end surface of the light guide plate and the reflecting portion of the heat radiating member and the heat radiating plate are in contact with each other in a state of being inserted into the portion.   The lighting unit according to claim 1, wherein the adhesive tape has a width equal to or greater than a width of the film substrate.   2. The lighting unit according to claim 1, wherein in a state where the light source unit is inserted into the housing portion, the reflection portion of the heat radiating member and the heat radiating plate are screwed.   2. The lighting unit according to claim 1, wherein the heat radiating member is fixed to the frame by screwing in a state where the light source unit is inserted into the housing portion.   The lighting unit according to claim 1, wherein the heat radiating member is made of a metal material.   The lighting unit according to claim 1, wherein a light emitting surface of the light emitting diode is separated from one end surface of the light guide plate. A liquid crystal display panel holding a liquid crystal layer between a pair of substrates;
An illumination unit that is disposed on the liquid crystal display panel and illuminates the liquid crystal display panel,
The lighting unit is:
A light guide plate;
A frame that holds the liquid crystal display panel and the light guide plate and is spaced from one end surface of the light guide plate;
A heat radiating plate that forms a cylindrical accommodating portion together with one end surface of the light guide plate and the frame;
A light source unit housed in the housing portion,
The accommodating portion is configured to be able to insert and remove the light source unit in the first direction,
The light source unit includes: a light emitting diode whose light emitting surface is substantially parallel to a mounting surface; a film substrate on which a plurality of the light emitting diodes are mounted side by side in the first direction; a support unit that supports the film substrate; A heat radiating member having a reflecting portion extending in a second direction orthogonal to the first direction from the supporting portion; and an adhesive tape that adheres the film substrate to the supporting portion and has a heat radiating property. A liquid crystal display device, wherein the light emitting surface of the light emitting diode faces the one end surface of the light guide plate and the reflective portion of the heat radiating member and the heat radiating plate are in contact with each other in a state of being inserted into the portion.

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