JP2007258089A - Light source device and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device and a display device that can suppress the adverse effect of warpage of an LED substrate and can effectively dissipate heat inside a light source cover. <P>SOLUTION: The light source device comprises an LED substrate on which a plurality of LEDs 13 are arranged, a mounting side of the LED substrate for mounting the LEDs 13 thereon being formed into a recessed surface; and a light source cover 12 attached so as to cover the LED substrate 11 with its mounting side for the LEDs 13 opened. In the display device, the light source device having such a configuration is mounted to a back plate of an apparatus body, and light is emitted to a display plate through a light guide plate having an incidence surface on which light from the LEDs of the LED substrate of the light source device is incident, the incidence surface being formed on the back side of the emitting surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light source device and a display device that use an LED as a light source such as a guide light or a marker lamp.

  A display device such as a guide light or a marker light is configured to emit light from the back surface of a display plate arranged in front of the instrument body to illuminate the display plate. Usually, the display plate of such a display device is flat, and it is necessary to illuminate the display plate with light having a flat spread.

For example, a plurality of LEDs are arranged in a straight line as a light source to form an LED substrate, a light guide plate having an exit surface substantially orthogonal to an incident surface on which light is incident is provided, and a plurality of LED substrates are provided on the light guide plate. There is one in which light from an LED is incident to obtain light having a planar spread (see, for example, Patent Document 1).
Japanese Patent Laying-Open No. 2004-265813 (FIG. 5)

  However, in such a display device using an LED as a light source and having a light guide plate, the LED substrate is positioned above the light guide plate, and is necessary for dissipating the heat generated by the LED on the LED substrate due to the external dimensions of the fixture body. It is difficult to secure a conductive area. That is, since the light source cover blocks the ambient atmosphere and the atmosphere in the light source cover, heat generated from the LED as the light source is accumulated inside the light source cover. Thereby, not only the luminous flux that promotes the deterioration of the LED is lowered, but also the LED substrate may be warped.

  The temperature of the LED mounting side of the LED board rises due to the heat generated by the LED, and the temperature on the opposite side is lower than that of the mounting side. Occurs. When the LED substrate is warped, it not only adversely affects the LED substrate, but also changes the direction of the luminous flux of the LED, resulting in unevenness of illumination on the display surface of the display panel.

  An object of the present invention is to provide a light source device and a display device that can suppress adverse effects due to warpage of an LED substrate and can efficiently dissipate heat inside the light source cover.

A light source device according to a first aspect of the present invention includes: an LED substrate in which a plurality of LEDs are arranged and the LED mounting side is formed in a concave surface; and the LED mounting side of the LED substrate is opened to cover the LED substrate In the present invention and the following invention, the definition and technical meaning of terms are as follows unless otherwise specified.

  Arranging a plurality of LEDs includes arranging them in a straight line as well as a staggered arrangement, and in short, means arranging a plurality of LEDs vertically or horizontally. The LED mounting side is the side where the light emitting part of the LED is attached. Being formed in a concave surface means an arc shape in which both end portions are substantially at the same position and the central portion is recessed. The degree of the dent in the center of the bow shape is preferably such that when the LED is continuously lit, the LED substrate warps due to the difference in thermal expansion between the LED mounting side and the opposite side of the LED substrate, and the LED substrate is flat. It will be about. As a result, the LED substrate is kept flat when the LEDs are continuously lit.

  The light source cover is open on the LED mounting side of the LED substrate. This is for allowing the emitted light from the light emitting part of the LED to pass through. The light source cover covers the LED substrate so that the LED substrate is not directly exposed when the LED substrate is incorporated into the instrument body of the display device, and protects the LED substrate from dust and impact.

  According to a second aspect of the present invention, there is provided a light source device comprising: an LED substrate on which a plurality of LEDs are arranged; and an LED substrate mounting side of the LED substrate that is open so as to cover the LED substrate and a heat radiation vent hole at an upper portion. And a light source cover having a light source cover.

  Arranging a plurality of LEDs, as in claim 1, includes a case where they are arranged in a straight line as well as a staggered arrangement, and the point is that a plurality of LEDs are arranged vertically or horizontally. The upper part of the light source cover is the direction in which the air heated by the heat generated by the LEDs on the LED substrate rises, and the heat radiation vent hole is a hole for releasing this air to the outside. The heat radiating vent hole may be provided with a flange for preventing dust from entering from the outside as necessary.

  A light source device according to a third aspect of the present invention is the light source device according to the first aspect, wherein a heat radiating sheet having a concave portion at the center is provided corresponding to the concave surface of the LED substrate, and the light source cover is interposed through the heat radiating sheet. The LED board is attached so as to cover it.

  According to the present invention, in contrast to the invention of claim 1, a heat radiation sheet having a concave portion formed in the center corresponding to the concave surface of the LED substrate is provided, and a light source cover is attached so as to cover the LED substrate via the heat radiation sheet. It is.

  A light source device according to a fourth aspect of the present invention is the light source device according to any one of the first to third aspects; the light incident surface from the LED of the LED substrate of the light source device is formed on the back side of the output surface. A light guide plate; housing a lighting unit for controlling the lighting of the LED and holding the light source device therein; and a display plate formed on a front surface portion of the fixture body and provided on an output surface of the light guide plate It is characterized by comprising;

  The light guide plate receives light from the LEDs on the LED substrate of the light source device, and guides and emits the light to the back side of the display plate. The incident surface of the light guide plate is formed on the back side of the output surface. That is, the light guide plate is formed so that the incident surface and the output surface are in the same direction. In addition, since the display plate formed on the front surface of the instrument body is provided on the exit surface of the light guide plate, the light source device that enters the light on the incident surface of the light guide plate is located on the back side of the display plate in the instrument body, Attached to the back of the instrument body. Therefore, the back side of the instrument body can be secured as a necessary conductive area for radiating heat generated by the LED.

  According to the first aspect of the present invention, since the LED substrate is formed to be concave in advance, it is possible to absorb the warpage of the LED substrate when the LED is continuously lit. Therefore, illumination with good visibility of the display board can be performed.

  According to the second aspect of the present invention, since the heat radiation vent hole is provided in the upper portion of the light source cover covering the LED substrate, the heat accumulated in the vicinity of the LED substrate can be radiated. That is, since the air heated by the heat generated by the LED moves upward, it can be efficiently discharged from the heat radiating vents at the top of the light source cover.

  According to the invention of claim 3, since the heat radiation sheet having the concave portion formed in the center portion corresponding to the concave surface of the LED substrate is provided on the LED substrate formed to be concave in advance, the heat of the LED substrate is efficiently obtained. Heat can be dissipated.

  According to the invention of claim 4, the light from the LED of the LED substrate of the light source device is incident on the incident surface of the light guide plate whose incident surface is formed on the back side of the output surface. It is located on the back side of the display board. Therefore, it is not necessary to provide a light source cover on the upper part of the display board, and the back side of the instrument body can be secured as a necessary conductive area for dissipating heat generated by the LEDs. Thereby, it is possible to provide a display device that has good visibility and can efficiently dissipate heat from the LED.

(First embodiment)
FIG. 1 is a partially cutaway perspective view of a light source device according to a first embodiment of the present invention. FIG. 1A is a perspective view showing a state before an LED substrate is mounted on a light source cover. b) is a perspective view showing a state after the LED substrate is mounted on the light source cover.

  As shown in FIGS. 1A and 1B, the light source device includes an LED substrate 11 and a light source cover 12. The LED board 11 has a connector 14 for connecting the LED 13 of the LED board 11 to the lighting unit at the end thereof. The wiring 15 from the connector 14 is connected to the lighting unit, and the lighting power of the LED 13 is supplied from the lighting unit.

  The LED substrate 11 has a plurality of LEDs 13 arranged therein, and the mounting side of the LEDs 13 is formed in a concave surface. That is, the LED substrate 11 is formed in a bow shape so that the substantially central portion is concave. 1 (a) and 1 (b) show a case where a plurality of LEDs 13 are arranged in a straight line on the LED substrate 11, a plurality of LEDs 13 are arranged in a staggered manner in a portrait or landscape orientation. Also good.

  On the other hand, the light source cover 12 has an opening at a portion where the LED 13 of the LED substrate 11 is mounted, and the portion where the LED substrate 11 is mounted has a heat sink whose central portion is concave according to the bow shape of the LED substrate 11. A sheet 16 is provided. The LED substrate 11 is disposed on the heat dissipation sheet 16 and attached to the light source cover 12 so that the LEDs 13 face the outside of the opening.

  2 is a cross-sectional view taken along line XX in FIG. 1B, FIG. 2A is a cross-sectional view when the light source device is manufactured, and FIG. 2B is a state in which the LEDs 13 of the light source device are continuously lit. FIG.

  As shown in FIG. 2A, the LED substrate 11 is formed in a bow shape so that the substantially central portion on the mounting side of the LED 13 is a concave surface at the time of manufacture. That is, the both ends of the LED substrate 11 are maintained at substantially the same position, and the side on which the light emitting portion of the LED 13 is attached is formed as a concave surface. In addition, a heat radiating sheet 16 having a concave central portion is provided at a portion where the LED substrate 11 on the light source cover 12 side is mounted, corresponding to the LED substrate 11 formed in a bow shape. The heat radiation sheet 16 is made of a material having elasticity and stretchability.

  Next, the degree of depression at the center of the LED substrate 11 is set such that the LED substrate 11 becomes flat as shown in FIG. 2B when the LED 13 is continuously lit. This is because, when the LED 13 is in a continuous lighting state, the heat generation of the LED 13 increases the thermal expansion of the LED board 11 on the LED mounting side, and the LED board 11 extends from the opposite side of the LED mounting side. That is, due to the difference in thermal expansion between the LED mounting side of the LED board 11 and the opposite side, the LED board 11 is warped in the direction opposite to the LED mounting side. This is because the LED is warped in the LED mounting side direction.

  Further, the LED substrate 11 and the heat radiating sheet 16 are bonded to each other at the concave portion at the center and not bonded at the end of the LED substrate 11. As a result, when the LED board 11 becomes flat due to the warping of the LED board 11 when the LED 13 is continuously lit, the central portion of the heat radiation sheet 16 expands according to the warping of the LED board 11 and is flat. And the extension of the LED substrate 11 is absorbed at the end of the LED substrate 11.

  According to the first embodiment, when the LED is continuously lit, the LED substrate 11 is preliminarily bent by the difference in thermal expansion between the LED 13 mounting side of the LED substrate 11 and the opposite side. Is formed so as to be concave, so that the LED substrate is flat when the LED is continuously lit. Therefore, since the direction of the light flux of the LED does not change in the continuous lighting state of the LED, it is possible to perform illumination with good visibility of the display board.

(Second Embodiment)
FIG. 3 is an external perspective view of the light source cover of the light source device according to the second embodiment of the present invention. In the second embodiment, in contrast to the first embodiment shown in FIG. 1, a heat radiating vent hole 17 is provided in the upper part of the light source cover 12.

  In FIG. 3, a heat radiation vent hole 17 for heat radiation is provided in the upper part of the light source cover 12. The heat radiating vent hole 17 is provided with a flange 18 to prevent dust from entering the light source cover 12 from the outside. Now, it is assumed that an opening for emitting light from the LED of the LED substrate is formed on the left side surface of the light source cover 12. In that case, light from the LED on the LED substrate is emitted in the direction of the arrow. When the LED lights up, it generates heat. The air heated by the heat generated by the LED flows in the upward direction. The air heated by this heat generation is discharged to the outside from the heat radiation vent hole 17.

  In the above description, the case of the first embodiment in which the LED board 11 on which the mounting side of the LED 13 is formed to be concave has been described has been described, but it goes without saying that the present invention can also be applied to the case where the LED board 11 is a flat plate. .

  According to the second embodiment, the air heated by the heat generated by the LEDs 12 of the LED board 11 is discharged to the outside from the heat dissipation vents 17 provided in the upper part of the light source cover 12, so that the inside of the light source cover 12 can be efficiently performed. The heat can be released.

(Third embodiment)
FIG. 4 is a partially exploded perspective view of a display device according to the third embodiment of the present invention. FIG. 4 shows a case where the display device according to the third embodiment of the present invention is a guide light for guiding to an emergency exit. A lighting unit 20 and a battery 21 for controlling lighting of LEDs are housed in the instrument body 19. A power supply hole 22 and a mounting hole 23 are provided at substantially the center of the upper surface portion and the rear surface portion of the instrument main body 19. A power line for supplying power from an external power source through the power hole 22 is drawn into the instrument body 19. A power line from an external power source drawn into the instrument main body 19 is connected to the terminal block 24, and each element in the instrument main body 19 such as the lighting unit 20 and the battery 21 from the terminal block 24, as well as a light source section described later. Power is supplied to the LED. The battery 21 normally charges power from an external power source, and supplies power to each element in the instrument body 19 when the external power source fails. In addition, an inspection switch 25 for checking the charging state of the battery 21 and the lighting state of the LED is housed in the instrument body 19.

  A display plate 26 is supported by a front frame 27 on the front surface of the instrument body 19. The light source device according to the first embodiment or the second embodiment is attached to the back surface of the display panel 26. That is, a light source cover 12 that houses an LED substrate on which a plurality of LEDs are mounted is mounted, light from the LEDs enters the light guide plate 28, and the light guide plate 28 guides light to the back surface of the display plate 26. Illuminate. As a result, the figures, characters, and the like drawn on the display board 26 are illuminated and displayed. FIG. 4 shows the display board 26 on which a symbol for guiding the emergency exit is drawn.

  FIG. 5 is a cross-sectional view of the light guide plate 28 and the light source device provided on the back surface of the display plate 26.

The light source device includes an LED substrate 11 on which a plurality of LEDs 13 are mounted, and a light source cover 12 that houses the LED substrate 11. The light guide plate 28 guides light from the LEDs 13 on the LED substrate 11 to the display plate 26. Is.

  The light guide plate 28 has a protrusion 29, an incident surface 30 is provided on the protrusion 29, and an output surface 31 is provided in the front direction of the incident surface 30. In addition, a reflection sheet 29 is provided on a surface other than the entrance surface 31 and the exit surface 31 of the light guide plate 28. The light source device is disposed on the back surface of the incident surface 30 of the protrusion 29 of the light guide plate 28, and the light source cover 12 of the light source device is attached to the back plate of the instrument body 19.

  Here, the protrusions 29 are provided on the light guide plate 28 because the distance between the light incident surface 30 and the light exit surface 31 is maintained at a predetermined length or more, and the bright spot of the LED 13 of the light source device is This is to prevent it from appearing on the display surface. That is, the length of the protruding portion 29 of the light guide plate 28 is set to such a length that the bright spot of the LED 13 does not appear on the display surface of the display plate 26. The reason why the light source cover 12 of the light source device is attached to the back plate of the instrument main body 19 is to dissipate heat generated by the LEDs on the back of the instrument main body 19 via the light source cover 12.

  In this way, the incident surface 30 of the light guide plate 28 is provided on the back side of the output surface 31, and light from the LED 13 of the light source device attached to the instrument main body 19 is incident from the incident surface 30, and all of the light guide plate 28 is within the light guide plate 28. The light is reflected and emitted from the emission surface 31 to the display panel 26. Thereby, the display plate 26 is illuminated using the light from the LEDs 13 of the LED substrate 11 as a surface light source.

  According to the third embodiment, the light guide plate 28 in which the light incident surface 30 is provided on the back surface side of the light output surface 31 with a predetermined length is formed, and the light output surface is totally reflected within the light guide plate 28. 31 and the display plate 26 provided on the exit surface 31 is illuminated, so there is no need to worry about the bright spot of the LED 13. In addition, since the light source device is provided on the back plate in the fixture main body on the back of the display plate 26, not on the upper portion of the display plate 26, the back side of the fixture main body can be secured as a necessary conductive area for radiating the heat generated by the LEDs. . Therefore, the heat dissipation effect is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway perspective view of a light source device according to a first embodiment of the present invention. FIG. 1A is a perspective view showing a state before an LED board is mounted on a light source cover, and FIG. The perspective view which shows the state after mounting | wearing of the LED board to a light source cover. FIG. 2B is a cross-sectional view taken along line XX in FIG. 1B, FIG. 2A is a cross-sectional view when the light source device is manufactured, and FIG. 2B is a cross-section when the LED 13 of the light source device is in a continuous lighting state. Figure. The external appearance perspective view of the light source cover of the light source device concerning the 2nd Embodiment of this invention. The partial exploded perspective view of the display apparatus concerning the 3rd Embodiment of this invention. Sectional drawing of the light-guide plate and light source device which were provided in the back surface of the display board in the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... LED board, 12 ... Light source cover, 13 ... LED, 14 ... Connector, 15 ... Wiring, 16 ... Radiation sheet, 17 ... Radiation vent, 18 ... Gutter, 19 ... Appliance body, 20 ... Lighting unit, 21 ... Battery, 22 ... Power supply hole, 23 ... Mounting hole, 24 ... Terminal block, 25 ... Inspection switch, 26 ... Display plate, 27 ... Front frame, 28 ... Light guide plate, 29 ... Protrusion, 30 ... Incident surface, 31 ... Output surface

Claims (4)

An LED substrate in which a plurality of LEDs are arranged and the mounting side of the LEDs is formed in a concave surface;
A light source cover attached so as to cover the LED substrate by opening the LED mounting side of the LED substrate;
A light source device comprising: An LED substrate on which a plurality of LEDs are arranged;
A light source cover attached to the LED substrate so as to cover the LED substrate by opening the LED mounting side;
A light source device comprising:   The heat radiation sheet having a concave portion at the center is provided corresponding to the concave surface of the LED substrate, and the light source cover is attached so as to cover the LED substrate via the heat radiation sheet. The light source device described. A light source device according to any one of claims 1 to 3;
A light guide plate in which an incident surface of light from the LED of the LED substrate of the light source device is formed on the back side of the emission surface;
An instrument body that houses a lighting unit that controls lighting of the LED and holds the light source device therein;
A display panel formed on the light emitting plate and formed on the front surface of the instrument body;
A display device comprising:

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