JP2012216434A - Lighting device, and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device capable of having no effect of thermal expansion of an optical coupling member elongated in one direction and easily manufacturing.SOLUTION: A backlight 10 includes a light guide plate 13, a flat plate-shaped chassis 11 for supporting the light guide plate 13, and a light source module 20 for irradiating light to the light guide plate 13. The light source module 20 includes a light source unit containing an elongated optical coupling member 30 extended in one direction, which makes LED chips 25a, 25b and light emitted from the LED chips 25a, 25b couple to the light guide plate 13, and a light source holder 21 for supporting the light source unit being movable in the longitudinal direction of the optical coupling member 30. The optical coupling member 30 is arranged between the light guide plate 13 and the LED chips 25a, 25b, and couples the emitted light of the LED chips 25a, 25b so as to make the light incident to the light guide plate 13 in a slanting state. Further, the light source holder 21 is mounted on a chassis 11.

Description

  The present invention relates to an illuminating device used as a backlight of a liquid crystal display device, for example, and an electronic apparatus including the illuminating device.

  A liquid crystal display device displays an image by light from the outside, and generally includes a backlight that emits the light. As such a backlight, a backlight of a type directly below a light guide plate in which a plurality of LEDs (light emitting diodes) are arranged in a two-dimensional matrix and a light guide plate is arranged on the plurality of LEDs is known.

  For example, Patent Document 1 discloses an illumination device in which a plurality of two-dimensional matrix-shaped insertion holes are formed in an LED mounting substrate, and an LED chip is inserted into each insertion hole.

JP 2009-266624 A (published on November 12, 2009) JP 2011-013331 A (published January 20, 2011)

  In the backlight directly under the light guide plate as described above, it is conceivable to arrange light coupling members (lenses) having various shapes in order to allow light from the LED chip to enter the light guide plate at a desired angle. For example, it is conceivable to arrange a long lens extending in one direction as disclosed in Patent Document 2 on a plurality of LED chips. When such a lens extending in one direction is disposed, the lens expands in the one direction due to heat generated from the LED chip. As a result, stress is applied to the lens, causing problems such as deterioration of optical performance and damage. Therefore, it is conceivable to provide a movable mechanism as described in Patent Document 2. However, the liquid crystal display device is relatively large, and there is a problem that it is difficult to process to provide a movable mechanism in the chassis of the liquid crystal display device.

  The present invention has been made to solve the above problems, and provides an illumination device and an electronic apparatus that are not affected by thermal expansion of an optical coupling member extending in one direction and that are easy to manufacture. With the goal.

  In order to solve the above problems, an illumination device of the present invention is an illumination device including a light guide plate, a flat chassis that holds the light guide plate, and a light source module that emits light to the light guide plate. The light source module includes a light source unit including a light source and a long light coupling member extending in one direction for optically coupling light emitted from the light source to the light guide plate, and a slide in the longitudinal direction of the light coupling member. A support member that movably supports the light source unit, and the light coupling member is disposed between the light guide plate and the light source so that light is incident obliquely on the light guide plate. The emitted light of the light source is combined, and the support member is attached to the chassis.

  According to said structure, a light-guide plate, an optical coupling member, and a light source will be arrange | positioned in this order. For this reason, the light emitted from the light source below the light guide plate is coupled to the light guide plate through the optical coupling member and incident obliquely, and moves to the end of the light guide plate while totally reflecting inside the light guide plate. In the middle, the total reflection condition is appropriately broken in the optical path conversion element, emitted from the light guide plate, reflected by the reflection sheet, and further emitted from the liquid crystal panel side surface of the light guide plate while passing through the light guide plate, It goes to the liquid crystal panel through the diffusion sheet and the prism sheet.

  In addition, even if the long optical coupling member extending in one direction expands in the longitudinal direction due to heat generated from the light source, the light source unit is arranged in the longitudinal direction of the optical coupling member on the support member according to the expansion amount. Slide in the direction. Therefore, unnecessary stress is not applied to the optical coupling member, the optical performance of the optical coupling member can be maintained, and damage or the like can be prevented.

  Furthermore, since the support member separate from the chassis supports the light source unit so as to be slidable, the relatively large chassis can be formed in a simple shape, and the processing of the chassis can be simplified. Further, the support member only needs to support the light source unit, and can be smaller in size than the chassis. Then, a mechanism for sliding the light source unit may be provided on the support member having a relatively small size, and there is an advantage that it is easy to perform processing for the mechanism, that is, it is easy to manufacture the lighting device.

  As described above, according to the above configuration, it is possible to provide an illumination device that is not affected by the thermal expansion of the optical coupling member extending in one direction and is easy to manufacture.

  Furthermore, in the lighting device of the present invention, the support member is attached to the back surface of the surface of the chassis that holds the light guide plate, and the chassis has a slit or an opening in a portion facing the support member. It is preferable.

  According to said structure, only the light source module protrudes in the back surface side of the surface holding the light-guide plate in a chassis. Therefore, it is possible to reduce the thickness of parts other than the light source module. Moreover, the heat generated in the light source module can be released more efficiently.

  Furthermore, in the illumination device of the present invention, it is preferable that a plurality of the light sources are provided along the longitudinal direction of the optical coupling member.

  According to said structure, uniform light can be entered into a light-guide plate along the longitudinal direction of an optical coupling member. As a result, the light emitted from the light guide plate can also be made uniform along the longitudinal direction of the optical coupling member.

  In the illumination device of the present invention, the light source unit further includes a plate-like member on which the light source and the optical coupling member are mounted, and the plate-like member is the same as the longitudinal direction of the optical coupling member. The support member supports the plate-like member by a fixing member inserted into the elongated hole, and both ends of the fixing member and the elongated hole in the longitudinal direction. It is preferable that a gap is formed between at least one of the two.

  According to said structure, since the clearance gap is formed between the fixing member and at least one of the both ends in the longitudinal direction of the said long hole, the plate-shaped member is only the length of a long hole by the length of the clearance gap. It becomes movable in the direction, that is, the longitudinal direction of the optical coupling member.

  Furthermore, in the lighting device of the present invention, it is preferable that the plate-like member is a heat radiating plate. Thereby, the heat generated by the light source can be efficiently released.

  In addition, an electronic apparatus according to the present invention includes the above-described lighting device. Also with this configuration, it is possible to provide an electronic device that is not affected by the thermal expansion of the optical coupling member extending in one direction and is easy to manufacture.

  The illuminating device of the present invention is an illuminating device including a light guide plate, a flat chassis that holds the light guide plate, and a light source module that irradiates light to the light guide plate. A light source unit including a long light coupling member extending in one direction for optically coupling light emitted from the light source to the light guide plate, and supporting the light source unit slidable in the longitudinal direction of the light coupling member. A support member, and the light coupling member is disposed between the light guide plate and the light source, and couples light emitted from the light source so that light is incident obliquely on the light guide plate. The support member is attached to the chassis.

  Therefore, it is possible to provide an illumination device that is not affected by the thermal expansion of the optical coupling member extending in one direction and is easy to manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing a configuration of a liquid crystal display device according to an embodiment of the liquid crystal display device of the present invention. It is a perspective view which shows the whole structure of the light source module with which the said liquid crystal display device is provided. It is sectional drawing which shows the structure of the liquid crystal display device which shows the vicinity of a light source module. It is a perspective view which shows the light source holder with which the said light source module is provided. It is a perspective view which shows the light source unit with which the said light source module is provided. It is a disassembled perspective view which shows a part of light source unit. It is a disassembled perspective view which shows the method of attaching an LED board to a heat sink. (A) is sectional drawing which shows the optical path when the light radiate | emitted from the LED chip injects into a light-guide plate via the optical coupling member which has a paraboloid, (b) is principal part sectional drawing which shows the LED chip vicinity. It is. It is sectional drawing which shows an optical path when the light radiate | emitted from two LED chips injects into a light-guide plate through the optical coupling member which has a paraboloid and an ellipse surface. (A) is a front view which shows the structure of a liquid crystal display device, (b) is the side view. (A) is sectional drawing which shows the structure of a liquid crystal display device, (b) is a graph which shows the luminance distribution of the height direction of a light-guide plate. It is principal part sectional drawing which shows the structure of the edge part of the said liquid crystal display device. It is a disassembled perspective view which shows the assembly method of a light source module. It is a perspective view which shows the detailed structure of a light source module. FIG. 9 is a cross-sectional view showing a configuration of a modification of the light source module, and shows an optical path when light emitted from one LED chip enters the light guide plate through an optical coupling member having a parabolic surface. It is a top view which shows the structure of the modification of a light source module, and shows the incident direction when light injects into a light-guide plate from the double row optical coupling member which has a row of LED chips.

<Overall configuration of liquid crystal display device>
One embodiment of the present invention is described below with reference to FIGS.

  As shown in FIG. 1, a liquid crystal display device (electronic device) 1 according to the present embodiment includes a backlight (illumination device) 10, a diffusion sheet 2, a prism sheet 3, a liquid crystal panel 4, and a bezel 5 stacked in this order. It is configured. Therefore, the light emitted from the backlight 10 enters the liquid crystal panel 4 through the diffusion sheet 2 and the prism sheet 3. A desired image is displayed by partially changing the light transmittance in the liquid crystal panel 4. The liquid crystal panel 4 has a rectangular flat plate shape, and the diffusion sheet 2 and the prism sheet 3 have substantially the same shape as the liquid crystal panel 4.

<Backlight configuration>
The backlight 10 includes a light source module 20, a chassis 11, a reflection sheet 12, and a light guide plate 13 in order from the bottom (that is, in order from the liquid crystal panel 4).

  The light source module 20 has a long shape (band shape) extending in a direction parallel to the long side of the liquid crystal panel 4, and is disposed so as to face a central portion in the short side direction of the liquid crystal panel 4. That is, the light source module 20 is disposed along the horizontal direction (longitudinal direction) of the liquid crystal panel 4 and so as to face the center line in the vertical direction (short direction) of the liquid crystal panel 4.

  The chassis 11 is formed of a material such as iron, for example, and increases the strength of the backlight 10. In the chassis 11, a light coupling member 30 (not shown) in the light source module 20 is divided into two at a portion that contacts the light guide plate 13, and is configured by 11 a and 11 b. Similarly to the chassis 11, the reflection sheet 12 is also divided into two portions where a light coupling member (not shown) in the light source module 20 abuts against the light guide plate 13, and is configured by reflection sheets 12 a and 12 b. A slit 14 is formed between the chassis 11a and 11b and the reflection sheets 12a and 12b. Therefore, the light from the light source module 20 passes through the slit 14 and reaches the light guide plate 13.

  The light guide plate 13 is for guiding the light emitted from the light source module 20 to the liquid crystal panel 4 side, and has a flat plate shape.

<Configuration of light source module>
Next, the configuration of the light source module 20 will be described. FIG. 2 is a perspective view showing the overall configuration of the light source module 20. As shown in FIG. 2, the light source module 20 has a plurality of light source units 29 and the plurality of light source units 29 arranged in one direction. And a light source holder 21 to be supported. FIG. 3 is a cross-sectional view of the liquid crystal display device 1 showing the vicinity of the light source module 20. As shown in FIG. 3, the light source module 20 is disposed on the back side of the liquid crystal display device 1.

  FIG. 4 is a perspective view showing the entire light source holder 21. The light source holder 21 has a long shape (band shape) extending in one direction, and includes a holder main body portion 21a and a flange portion 21b. The holder main body 21a has a groove having a concave cross section (a U-shape). And the holder main-body part 21a supports the some light source unit 29 so that sliding (sliding) movement is possible in the bottom face of a groove | channel. The details of the mechanism that slidably supports the light source unit 29 will be described later. Moreover, the collar part 21b is extended in parallel with the bottom face of the holder main-body part 21a from the both ends along the longitudinal direction in the holder main-body part 21a. The flange portion 21b has a plurality of screw holes 21e to be attached to the chassis 11.

  FIG. 5 is a perspective view showing the light source unit 29. As shown in FIGS. 5 and 3, the light source unit 29 is emitted from LED substrates 24a and 24b on which LED chips (Light Emitting Diodes) 25a and 25b as light sources are mounted, and LED chips 25a and 25b. A long optical coupling member 30 as an optical element for coupling the light to be incident on the light guide plate 13 at a predetermined angle, and a plate shape on which the LED substrates 24a and 24b and the optical coupling member 30 are mounted. And a heat sink 22 as a member. The optical coupling member 30, the LED boards 24a and 24b, and the heat sink 22 are arranged in this order. Since the semiconductor LED chip has a very fine size, FIG. 5 omits the description for preventing the complexity of the drawing. In this embodiment, an LED chip is used as a light source. However, since a semiconductor chip-shaped LED is smaller in size and can be arranged in a narrow area, even when an inexpensive low-power LED chip is used. This is because it is preferable in that a large number of LEDs are arranged at close intervals to improve illuminance and to be used as a light source for a highly functional backlight. However, the present invention is not limited to this. For example, an LED housed in a package may be used, and an organic EL light emitting element or an inorganic EL light emitting element may be used.

  A plurality of LED chips 25a and 25b are provided in parallel in two rows. As shown in FIG. 6, the LED substrates 24a and 24b on which the plurality of LED chips 25a and 25b are mounted are provided. An optical coupling member 30 is provided on the upper side. Further, as shown in FIG. 7, the LED boards 24 a and 24 b are attached on the heat sink 22 with screws. The heat sink 22 is configured in a plate shape with a material having high thermal conductivity such as aluminum. Therefore, heat dissipation can be improved. Further, the length of the long optical coupling member 30 in the longitudinal direction (for example, 111 mm) is set slightly longer than the width of the heat sink 22 (for example, 110 mm). Thereby, as shown in FIG. 2, when a plurality of light source units 29 are arranged side by side, it is possible to reliably prevent a gap from being formed between the optical coupling members 30 in the adjacent light source units. .

  The optical coupling member 30 is provided on the LED chips 25a and 25b. That is, the LED chips 25a and 25b are arranged on the LED substrates 24a and 24b, and the optical coupling member 30 is disposed on the LED chips 25a and 25b. However, if the optical coupling member 30 is mounted as it is, the LED chips 25a and 25b are damaged, and therefore the optical coupling member 30 is disposed between the LED chips 25a and 25b with a slight gap in the height direction.

  As shown in FIGS. 8A and 8B, the optical coupling member 30 is a belt-like body having a substantially U-shaped section (tunnel shape) provided between the light guide plate 13 and the LED chips 25a and 25b, that is, a rod-shaped body. The optical coupling member 30 is made of the same resin as the light guide plate 13 (for example, acrylic resin). Since the refractive index can be made the same if they are the same material, the light is smoothly incident on the light guide plate 13 from the optical coupling member 30. The refractive index of the light guide plate 13 may be slightly higher than the refractive index of the optical coupling member 30. Further, the material is not limited to resin, and a material such as glass may be used. Specifically, as shown in FIG. 8A, the surface of the optical coupling member 30 on the light guide plate 13 side is a top flat surface 31 in contact with the flat light guide plate 13, and both end sides from the top flat surface 31. And reflecting surfaces 32a and 32b extending away from the light guide plate 13, respectively. The reflection surfaces 32a and 32b can be, for example, a cross-sectional parabola shown in FIG. However, the shape is not limited to this, and a part of an elliptical cross section, a curved shape such as an arc shape, or a plane that is inclined obliquely from the top flat surface 31 may be any shape that can effectively couple light to the light guide plate. I do not care. Thereby, the optical coupling member 30 functions to propagate the light emitted from the light source while being bent inside the optical coupling member and to make the light incident obliquely to the flat light guide plate. For this reason, most of the light from the light source can be coupled to the light guide plate.

  Further, the surface of the optical coupling member 30 opposite to the light guide plate 13 side, that is, the lower end of the optical coupling member 30 is two lower flat surfaces 33, and a height of 0. Spacers 23a and 23b of about 5 mm are formed to prevent the LED chips 25a and 25b from being damaged by the collision between the LED chips 25a and 25b and the optical coupling member 30. That is, thanks to the spacers 23a and 23b, the LED chips 25a and 25b are disposed between the LED substrates 24a and 24b and the two lower flat surfaces 33 of the optical coupling member 30, and the gaps that do not damage the LED chips 25a and 25b. Can be provided. The LED chip 25a is bonded to the LED substrate 24a. An adhesive or the like is applied in the vicinity of the spacer 23a, and is fixed to the LED substrate 24a.

  Further, a recess 34 is formed in the central portion on the lower end side of the optical coupling member 30. However, the present invention is not necessarily limited to this, and a cross-sectionally semi-cylindrical shape or a semicircular cross-sectional shape in which the recess 34 does not exist may be used. In other words, in the present embodiment, it is only necessary to secure an optical path to the light guide plate 13 for the light reflected by the reflecting surfaces 32a and 32b. Thereby, cost reduction can be aimed at. In addition, it is also possible to provide reflection means such as a reflection sheet (not shown) in the recess 34. Thereby, even if the stray light generated in the vicinity of the top flat surface 31 may occur, a part of the stray light can be reflected to the light guide plate 13 side to improve the irradiation to the liquid crystal panel 4.

  LED chips 25a and 25b are provided close to each other below the lower flat surface 33 of the optical coupling member 30, respectively. As shown in FIG. 8B, these LED chips 25a and 25b are preferably present on the end side with respect to the focal position F of the reflecting surfaces 32a and 32b having a cross-sectional parabola or a cross-sectional ellipse. Accordingly, as shown in FIG. 8A, for example, light emitted from the LED chip 25a is reflected by the reflecting surface 32a of the parabolic parallax of the optical coupling member 30, and the reflected light is flat on the top of the optical coupling member 30. The light reaches the surface 31 and enters the light guide plate 13 obliquely while maintaining the arrival direction. Then, the light incident on the light guide plate 13 travels by being totally reflected inside the right side of the light guide plate 13 shown in FIG. 8A, and is transmitted through an optical path conversion unit (not shown) formed on the lower surface or the upper surface of the light guide plate 13. Colliding with a light scatterer changes the angle of travel through the light guide plate 13, the total reflection condition is broken, the light is emitted from the light guide plate 13, reflected by the reflection sheet 12, and further passed through the light guide plate 13 to be guided. The light is emitted from the surface of the optical plate 13 on the liquid crystal panel 4 side and travels toward the liquid crystal panel 4 through the diffusion sheet 2 and the prism sheet 3. In addition, although the light radiate | emitted from LED chip 25b is not shown in FIG. 8 (a) (b), it progresses symmetrically with the light from LED chip 25a. FIG. 9 schematically shows a state in which light from the left and right LED chips 25a and 25b passes through the optical coupling element 30, enters the light guide plate 13, and propagates through the inside thereof.

  That is, as shown in FIG. 9, the light emitted from the LED chips 25 a and 25 b is reflected by the reflecting surfaces 32 a and 32 b having an elliptical cross section of the optical coupling member 30, and the reflected light is the top flat surface of the optical coupling member 30. 31, and enters the light guide plate 13 obliquely while maintaining the arrival direction. Then, the light incident on the light guide plate 13 changes the angle of traveling through the light guide plate 13 by colliding with a light scatterer which is an optical path changing unit (not shown) while totally reflecting inside the light guide plate 13 and traveling. The total reflection condition is broken, the light is emitted from the surface of the light guide plate 13 on the liquid crystal panel 4 side, and travels toward the liquid crystal panel 4 through the diffusion sheet 2 and the prism sheet 3. The light emitted from the LED chip 25a and the light emitted from the LED chip 25b travel in the light guide plate 13 symmetrically.

  Thus, by making the shape of the reflecting surfaces 32a and 32b in the optical coupling member 30 into a cross-sectional parabola or a cross-sectional ellipse, the light emitted from the LED chips 25a and 25b is reflected on the reflecting surfaces 32a and 32b having a cross-sectional parabola or a cross-sectional ellipse. Thus, the light can be reflected and efficiently combined to be incident on the light guide plate 13 from the top flat surface 31. In the comparison between the cross-section parabola and the cross-section ellipse, the cross-section ellipse can be coupled so that light is focused and incident on the light guide plate 13, so that the coupling efficiency can be increased.

  As a result, in the backlight 10 in the liquid crystal display device 1 of the present embodiment, as shown in FIGS. 10A and 10B, a long (band-like) shape is formed across the center of the screen of the liquid crystal display device 1. By providing the light source module 20, the emitted light from the light guide plate 13 having the luminance distribution shown in FIGS. 11A and 11B can be obtained. The luminance distribution that the center of the screen is bright matches the luminance distribution for displaying the liquid crystal display device 1 appropriately. For this reason, in the present embodiment, it is possible to obtain a uniform and smooth luminance distribution. As a result, it can be said that it is superior to the conventional side edge type backlight.

  Moreover, in the backlight 10 of this Embodiment, the light of LED chip 25a * 25b is introduced from the downward direction of the light-guide plate 13. FIG. Therefore, the light use efficiency is superior to the conventional side edge type backlight.

  Further, in the backlight 10 of the present embodiment, unlike the conventional side edge type backlight, as shown in FIG. 12, the end portion side (side edge portion) of the light guide plate 13, that is, the end of the liquid crystal panel 4 is used. Since there is no light source in the part, it is possible to provide the frame 6 directly at the end of the liquid crystal panel 4. As a result, a narrow frame can be achieved.

  Further, as shown in FIG. 3, the heat sink 22 is disposed on the most back side of the liquid crystal display device 1. Therefore, the heat dissipation effect becomes higher.

<Sliding mechanism of light source unit>
Next, the details of the mechanism that enables the light source unit 29 to slide in the light source holder 21, which is a characteristic configuration of the present invention, will be described. FIG. 13 is a view showing a mechanism for attaching the light source unit 29 to the light source holder 21.

  As shown in FIG. 13, a rivet hole 21c into which a rivet 28 for mounting the light source unit 29 is inserted corresponding to each of the plurality of light source units 29 is formed on the bottom surface of the groove of the holder main body 21a. A cylindrical projection 21 d for determining the position of the light source unit 29 is formed. The number of rivet holes 21c and protrusions 21d may be set as appropriate in consideration of the size of the light source unit 29 and the like.

  The heat sink 22 included in each light source unit 29 is formed with a fastening long hole 22a through which the rivet 28 passes and a fitting long hole 22b into which the protrusion 21d formed on the light source holder 21 is inserted. . The fastening elongated hole 22a and the fitting elongated hole 22b extend in the longitudinal direction of the optical coupling member 30 extending in one direction. The relative positional relationship between the fastening long hole 22a and the fitting long hole 22b in the heat sink 22 is relative to the rivet hole 21c corresponding to each light source unit 29 formed in the holder main body 21a and the protrusion 21d. Same as relationship.

  The light source unit 29 is installed on the bottom surface of the holder main body 21a so that the longitudinal direction of the light coupling member 30 and the longitudinal direction of the light source holder 21 (that is, the direction parallel to the groove) are parallel. At this time, the fastening long hole 22a of the heat sink 22 and the rivet hole 21c of the holder main body 21a overlap, and the protrusion 21d of the holder main body 21a is inserted into the fitting long hole 22b of the heat sink 22. A light source unit 29 is installed. The outer diameter of the cylindrical protrusion 21d is equal to or slightly smaller than the width in the short direction of the fitting long hole 22b.

  Then, a rivet (for example, a plastic rivet) 28 having a circular cross section is inserted into the rivet hole 21c through the fastening long hole 22a. The outer diameter of the rivet 28 is equal to or slightly smaller than the width in the short direction of the fastening long hole 22a.

  FIG. 14 is a perspective view showing a state when the light source unit 29 is attached to the light source holder 21 by the rivet 28. As shown in FIG. 14, the rivet 28 fixes the sheet-like heat sink 22 with respect to the light source holder so as not to move in the normal direction (z direction in the drawing).

  Further, the protrusion 21d of the light source holder 21 is inserted into the fitting long hole 22b of the heat sink 22, and the outer diameter of the protrusion 21d is equal to or slightly smaller than the width of the fitting long hole 22b in the short direction. . Here, the short direction of the fitting long hole 22b is perpendicular to the longitudinal direction of the fitting long hole 22b, and the direction perpendicular to the long direction of the optical coupling member 30 extending in one direction (the optical coupling member 30 (Short direction). Therefore, the light source unit 29 is fixed to the light source holder 21 so as not to move in the short direction (y direction in the figure) of the optical coupling member 30.

  On the other hand, the outer diameter of the protrusion 21d is equal to or slightly smaller than the width of the fitting long hole 22b, and the outer diameter of the rivet 28 is equal to the width of the fastening long hole 22a in the short direction. Or slightly smaller. That is, a gap is formed between the protruding portion 21d and at least one of both end portions in the longitudinal direction of the fitting elongated hole 22b. Similarly, a gap is formed between the rivet 28 and at least one of both end portions in the longitudinal direction of the fastening elongated hole 22a. As a result, the light source unit 29 can slide (move) relative to the light source holder 21 in the longitudinal direction (x direction in the drawing) of the optical coupling member 30 by the gap.

  As described above, the optical coupling member 30 is a lens (for example, acrylic glass) formed of a material such as acrylic resin. Such materials generally have a relatively high coefficient of thermal expansion. Therefore, it can be considered that the heat is generated by the heat generated by the LED chips 25a and 25b. The amount of expansion at that time increases in the longitudinal direction of the optical coupling member 30 extending in one direction. However, in the light source module 20 of this embodiment, the light source holder 21 supports the light source unit 29 so that it can slide along the longitudinal direction of the optical coupling member 30. Therefore, even if the optical coupling member 30 expands in the longitudinal direction, the light source unit 29 slides on the light source holder 21 in the longitudinal direction of the optical coupling member 30 according to the expansion amount. Therefore, unnecessary stress is not applied to the optical coupling member 30, and the optical performance of the optical coupling member 30 can be maintained, and damage or the like can be prevented.

  A light source holder 21 having a movable mechanism for slidably supporting the light source unit 29 is attached to the chassis 11. That is, the movable mechanism may be provided not on the chassis 11 but on the light source holder 21. The chassis 11 has substantially the same size as the liquid crystal panel 4 and is relatively large. When a movable mechanism is provided for such a large chassis 11, processing becomes difficult. However, in this embodiment, a movable mechanism may be provided in the relatively small light source holder 21 that supports only the light source unit 29. Therefore, the backlight 10 provided with the movable mechanism of the light source unit can be easily manufactured.

<Supplement>
As described above, the backlight (illumination device) 10 according to the present embodiment includes the light guide plate 13, the flat chassis 11 that holds the light guide plate 13, and the light source module 20 that irradiates the light guide plate 13 with light. I have. The light source module 20 includes LED chips 25a and 25b as light sources and a long light coupling member 30 extending in one direction for optically coupling light emitted from the LED chips 25a and 25b to the light guide plate 13. 29 and a light source holder 21 as a support member that supports the light source unit 29 so as to be slidable in the longitudinal direction of the optical coupling member 30. The optical coupling member 30 is disposed between the light guide plate 13 and the LED chips 25a and 25b, and couples the emitted light of the LED chips 25a and 25b so that light is incident on the light guide plate 13 obliquely. The light source holder 21 is attached to the chassis 11.

  According to said structure, even if the elongate optical coupling member 30 extended in one direction expanded in the longitudinal direction with the heat | fever emitted from LED chip 25a * 25b, the light source unit 29 is the expansion amount. Accordingly, the light coupling member 30 slides in the longitudinal direction on the light source holder 21. Therefore, unnecessary stress is not applied to the optical coupling member 30, and the optical performance of the optical coupling member 30 can be maintained, and damage or the like can be prevented.

  Further, a relatively large chassis 11 having substantially the same size as the liquid crystal panel 4 can be formed into a simple flat plate shape. Moreover, since the light source unit 29 including the heat sink 22 can be disposed on the back side of the chassis 11, heat dissipation can be further improved. Furthermore, a mechanism for sliding the light source unit 29 may be provided for the light source holder 21 that is smaller in size than the chassis 11, and there is an advantage that processing for the mechanism is easy to be performed.

  Furthermore, the light guide plate 13, the optical coupling member 30, and the LED chips 25a and 25b are arranged in this order. That is, in the liquid crystal display device 1 of the present embodiment, the LED chips 25a and 25b are provided below the light guide plate 13, and the light is emitted from the LED chips 25a and 25b between the light guide plate 13 and the LED chips 25a and 25b. An optical coupling member 30 is provided for coupling the light so that the incident light is obliquely incident on the flat light guide plate 13. For this reason, the light emitted from the LED chips 25a and 25b below the light guide plate 13 is coupled to the light guide plate 13 through the optical coupling member 30 and incident obliquely, and is guided while being totally reflected inside the light guide plate 13. While moving to the end of the light plate 13, the total reflection condition is broken by an optical path conversion element (not shown) in the middle, emitted from the light guide plate 13, reflected by the reflection sheet 12, and further passed through the light guide plate 13, The light is emitted from the surface of the light guide plate 13 on the liquid crystal panel 4 side and travels toward the liquid crystal panel 4 through the diffusion sheet 2 and the prism sheet 3.

  As a result, unlike the conventional side edge type light guide plate, the backlight is directly under the light guide plate, so that the frame size can be reduced and the design effect can be improved. Further, since the gap between the LED chips 25a and 25b and the light guide plate 13 for avoiding the thermal expansion required in the side edge type light guide plate is not required, light does not leak from the gap. That is, in this embodiment, the optical coupling member 30 and the LED chips 25a and 25b are disposed below the light guide plate 13, and the thickness direction of the light guide plate 13 has a smaller thermal expansion than the long or short planar direction. The expansion and contraction of the light guide plate 13 is small, and the optical coupling member 30 and the LED chips 25a and 25b can be brought close to each other. These gaps can be set to 0.5 mm or less, for example. Since the optical coupling member 30 is in contact with the light guide plate 13, there is no gap. For this reason, the coupling efficiency from the LED chips 25a and 25b to the light guide plate 13 can be increased, and the light utilization efficiency can be improved.

  Further, the light source holder 21 is attached to the rear surface of the surface of the chassis 11 that holds the light guide plate 13 (the surface that contacts the light guide plate 13). The chassis 11 has a slit 14 at a portion facing the light source holder 21. is doing. In FIG. 3, the chassis 11 is divided into a plurality of parts and the slit 14 is formed in a portion facing the light source holder 21. However, the present invention is not limited to this. In short, the slit 14 is provided in the portion of the chassis 11 facing the light source holder 21 so that light can be emitted from the optical coupling member 30 to the light guide plate 13 without being blocked by the chassis 11. Therefore, any configuration that can embody such technical idea is acceptable. For example, by forming an opening in a portion of the chassis 11 that faces the light source holder 21, it is possible to have a configuration that allows light to be emitted from the optical coupling member 30 to the light guide plate 13. Various configurations can be employed.

  According to said structure, only the light source module protrudes in the back surface side of the surface holding the light-guide plate 13 in the chassis 11. FIG. Accordingly, it is possible to reduce the thickness of parts other than the light source module 20. Further, the heat generated in the light source module 20 can be released more efficiently.

  The light source unit 29 further includes a heat sink (heat radiating plate) 22 as a plate-like member on which the LED chips 25a and 25b and the optical coupling member 30 are mounted. The heat sink 22 has a fastening long hole 22 a and a fitting long hole 22 b whose longitudinal direction is the same as the longitudinal direction of the optical coupling member 30. The light source holder 21 supports the heat sink 22 by rivets 28 and protrusions 21d as fixing members inserted into the fastening elongated holes 22a and the fitting elongated holes 22b. Here, a gap is formed between the rivet 28 and the protruding portion 21d and at least one of both end portions in the longitudinal direction of the fastening elongated hole 22a and the fitting elongated hole 22b. Accordingly, the heat sink 22 is movable in the longitudinal direction of the fastening elongated hole 22a and the fitting elongated hole 22b, that is, in the longitudinal direction of the optical coupling member 30.

  Moreover, since the heat sink 22 is used as the plate-like member, the heat dissipation can be improved.

  In the present embodiment, by providing the optical coupling member 30 that is separate from the light guide plate 13, light is incident on the flat light guide plate 13 at an angle, so that incident light is incident inside the light guide plate 13. Is guided while being totally reflected.

  In other words, in the present embodiment, the optical coupling member 30 has a semicircular cross section in which the top part comes into contact with the light guide plate 13.

  As a result, incident light from the LED chips 25 a and 25 b via the optical coupling member 30 can be guided inside the light guide plate 13 without processing the light guide plate 13. For this reason, since light guide plate 13 itself is sufficient with a simple flat plate, processing for large light guide plate 13 is not required. Moreover, although it is difficult to process the light guide plate 13, the processing of the optical coupling member 30 is easier than that, and the manufacturing cost can be reduced.

  Further, in the present embodiment, the LED chips 25 a and 25 b are arranged so that the optical axis direction of the incident light to the optical coupling member 30 is orthogonal to the flat light guide plate 13. For this reason, the LED chips 25a and 25b do not need to be inclined with respect to the flat light guide plate 13, so the LED chips 25a and 25b can be easily arranged, and the structure and assembly method are simple.

  Therefore, the liquid crystal display device 1 that can increase the coupling efficiency from the LED chips 25a and 25b to the light guide plate 13 and improve the light utilization efficiency without processing the light guide plate 13 can be provided.

  In the present embodiment, the light guide plate 13 is not processed and light is incident from below (that is, from the back side of the light guide plate 13), so that the liquid crystal display device 1 of the light guide plate 13 is thinned. be able to. Specifically, a certain amount of thickness is required for processing the light guide plate 13. In this case, the conventional edge light system has a limit in reducing the thickness because the light coupling rate decreases when the light guide plate is made thinner than the width of the light source. In this regard, in the present embodiment, if the light guide plate 13 is thinned, the television is thinned and lightened. Moreover, since the material of the light guide plate 13 can be saved, the cost can be reduced from the point that processing is unnecessary. Further, since the LED chips 25a and 25b may be mounted upward, in the assembly of the respective member groups constituting the liquid crystal display device shown in FIG. 1 including the LED chips 25a and 25b, the assembly direction is one assembling direction. The assembly manufacturing apparatus configuration and assembly work are simplified. That is, in the case of the conventional edge light, since it is necessary to attach a light source from the side, manufacture becomes a little difficult.

  Moreover, in the liquid crystal display device 1 of this Embodiment, the optical coupling member 30 is provided in strip | belt shape. Further, the optical coupling member 30 provided in the belt shape is provided in parallel to the longitudinal direction of the light guide plate 13 having a rectangular flat plate shape.

  This eliminates the need for the relationship between the optical coupling member 30 and the LED chips 25a and 25b to be 1: 1, and the plurality of LED chips 25a and 25b are covered by the single optical coupling member 30, so that the structure of the optical system can be improved. It can be simplified. Moreover, since LED chip 25a * 25b can also be provided along the optical coupling member 30, wiring of LED chip 25a * 25b becomes easy.

  In the configuration in which the optical coupling member 30 is provided in a strip shape, the optical coupling member 30 may be a double row. In this case, in particular, it is preferable to arrange the light guide plates 13 symmetrically on the vertical or horizontal center line so that the luminance distributions of the double-row optical coupling members 30 are symmetrical. In addition, when the optical coupling members 30 are in a double row, it is desirable that the central luminance on the screen of the liquid crystal panel 4 is higher than the luminance at the screen edge.

  Moreover, in the liquid crystal display device 1 of this Embodiment, it is preferable that the optical coupling member 30 is provided on the vertical or horizontal center line in the flat light guide plate 13.

  That is, in the liquid crystal display device 1, the screen is easier to see when the luminance on the vertical or horizontal center line of the liquid crystal panel 4 is increased. In this regard, in the present embodiment, since the optical coupling member 30 is provided on the vertical or horizontal center line of the flat light guide plate 13, the luminance on the vertical or horizontal center line of the light guide plate 13 is high. The highest. Therefore, it is possible to provide the liquid crystal display device 1 suitable for the luminance distribution.

  In the liquid crystal display device 1 of the present embodiment, a plurality of LED chips 25 a and 25 b are provided along the longitudinal direction of the optical coupling member 30. Thereby, uniform light can be incident on the light guide plate 13 along the longitudinal direction of the optical coupling member 30. As a result, the light emitted from the light guide plate 13 can be made uniform along the longitudinal direction of the optical coupling member 30.

  Further, the LED chips 25 a and 25 b are provided in two rows along the longitudinal direction of the optical coupling member 30. Specifically, the LED chips 25a and 25b are provided in two rows in parallel along the center line immediately below both ends of the lower end chord in the optical coupling member 30 having a semicircular cross section.

  As a result, when light is incident on the light guide plate 13, the two rows of LED chips 25a and 25b emit light in opposite directions, whereby the line passing through the midpoint between the two rows is axially symmetric and both sides of the optical coupling member 30. That is, the light can be guided to both ends of the light guide plate 13. When the line passing through the midpoint between the two rows coincides with the center line of the light guide plate 13, the light guide plate is guided to both ends of the light guide plate with the center line of the light guide plate 13 being axially symmetrical. A luminance distribution that is axially symmetric about the 13 center lines can be obtained. Therefore, the luminance distribution can be made uniform in the light guide plate 13 with a simple structure. That is, when the LED chip 25a is single, there is a possibility that the portion directly above the LED chip 25a does not transmit light and becomes a dark part. This can be supplemented with light from other LED chips 25b.

  Moreover, in the liquid crystal display device 1 of this Embodiment, the light source consists of several LED chip 25a * 25b.

  As a result, the LED chips 25a and 25b are small in shape and can be densely arranged at a minute interval, thereby making it possible to increase the illuminance as a whole, which is suitable as a light source for the backlight 10.

  In the present embodiment, the light source module 20 is provided with two rows of LED chips 25a and 25b. However, the present invention is not necessarily limited to this. For example, as shown in FIG. 15, it is also possible to provide the optical coupling member 40 only on one side having the reflection surface 32a having a cross-sectional parabola or a cross-sectional ellipse. As a result, the LED chips 25 a can be configured to be provided in a line along the longitudinal direction of the optical coupling member 40.

  Regarding the optical coupling member 40, as a first embodiment, for example, the optical coupling member 40 is not provided on the center line in the vertical or horizontal direction of the light guide plate 13, but is provided at the end of the light guide plate 13, and from the LED chip 25a. The light can be made incident at the end of the light guide plate 13. With this configuration, light can be extracted from the entire surface of the light guide plate 13 that is guided in one direction in the light guide plate 13, and the entire surface of the liquid crystal panel 4 can be irradiated.

  As a second embodiment, the optical coupling member 40 can be provided on the vertical or horizontal center line of the light guide plate 13. Even in this case, for example, since the return light of the light guided to the right side of the center line is also guided to the left side of the center line, the entire surface of the liquid crystal panel 4 can be irradiated.

  Furthermore, as another embodiment in which the LED chips 25a are provided in one row along the longitudinal direction of the light coupling member 40, for example, as shown in FIG. 13, the light coupling member 40a having one row of LED chips 25a, and 1 The optical coupling members 40b having the LED chips 25b in a row can be arranged in a double row so that the emission directions of the LED chips 25a and 25b are opposed to each other. That is, in FIG. 13, the light indicated by the arrow pointing toward the right side of the paper is light emitted from the LED chip 25 a included in the optical coupling member 40 a, and the light indicated by the arrow pointing toward the left side of the paper is light. The optical coupling members 40a and 40b are configured so as to be light emitted from the LED chip 25b included in the coupling member 40b. With such a configuration, it is possible to emit light to both sides of the light guide plate 13 and to eliminate luminance unevenness on the reflecting portions of each other. In other words, it can be said that the configuration in which two rows of LED chips 25a and 25b are provided on one optical coupling member 30 described above is a configuration in which the configuration shown in FIG.

  In the present embodiment, the backlight 10 is applied to the liquid crystal display device 1. However, the present invention is not necessarily limited thereto, and for example, the backlight 10 can be applied to a lighting device. That is, the backlight 10 of the present embodiment can be applied to a large planar light source as it is. Further, since no member is required around the light guide plate 13, it can be applied to a larger planar light source by arranging them seamlessly.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the embodiments can be obtained by appropriately combining the technical means disclosed in the embodiments. The form is also included in the technical scope of the present invention.

  The present invention can be used for a backlight of a liquid crystal display device such as a television or a monitor, and is particularly applicable to a backlight directly under the light source. The backlight can be applied to a lighting device as a large planar light source.

1 Liquid crystal display device (electronic equipment)
4 Liquid crystal panel 10 Backlight (lighting device)
DESCRIPTION OF SYMBOLS 11 Chassis 13 Light-guide plate 14 Slit 20 Light source module 21 Light source holder 21a Holder main-body part 21b Eaves part 21c Rivet hole 21d Protrusion part (fixing member)
22 Heat sink (plate-like member, heat sink)
22a Long hole for fastening (long hole)
22b Long hole for mating (long hole)
24a / 24b LED board 25a / 25b LED chip (light source)
28 Rivet (fixing member)
29 Light source unit 30/40 Optical coupling member

Claims (6)

A light guide plate;
A flat chassis for holding the light guide plate;
A lighting device including a light source module that irradiates light to the light guide plate,
The light source module is slidable in the longitudinal direction of the light coupling member, including a light source unit including a light source and a long light coupling member extending in one direction for optically coupling light emitted from the light source to the light guide plate. And a support member for supporting the light source unit,
The optical coupling member is disposed between the light guide plate and the light source, and couples light emitted from the light source so that light is incident obliquely on the light guide plate,
The lighting device, wherein the support member is attached to the chassis. The support member is attached to the rear surface of the surface holding the light guide plate in the chassis,
The lighting device according to claim 1, wherein the chassis has a slit or an opening at a portion facing the support member.   The lighting device according to claim 1, wherein a plurality of the light sources are provided along a longitudinal direction of the optical coupling member. The light source unit further includes a plate-like member on which the light source and the optical coupling member are mounted,
The plate-like member has a long hole whose longitudinal direction is the same as the longitudinal direction of the optical coupling member,
The support member supports the plate-like member by a fixing member inserted into the elongated hole,
The lighting device according to any one of claims 1 to 3, wherein a gap is formed between the fixing member and at least one of both end portions in the longitudinal direction of the elongated hole.   The lighting device according to claim 4, wherein the plate member is a heat radiating plate.   An electronic apparatus comprising the illumination device according to claim 1.