JP4523421B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device that emits light in a ring shape along the outer periphery of a switch, and makes it easy to confirm, for example, the ON / OFF state of the switch by light emission around the switch.

  Conventionally, an annular light guide is provided around a switch, and light is emitted from the light source to the light guide according to the operation of the switch, so that the outer periphery of the switch emits light. For example, see Patent Document 1). The light source emits light from below the light guide toward the light guide, and the light from the light source introduced into the light guide travels inside the light guide and emits light in a ring shape.

  However, the light from the light source is relatively strong in the vicinity of the optical axis, and if the light is irradiated with the light source facing a part of the light guide, it is introduced into the light guide and transmitted in an annular shape. Even so, there is a difference in brightness between the vicinity of the light source and other parts.

  Therefore, it is conceivable to arrange a large number of light sources in a ring shape along the light guide to reduce the difference in brightness between the optical axes of the light sources adjacent to each other, but the number of parts increases by using a large number of light sources. However, there is a risk that the production efficiency is reduced and the cost is increased.

In order to eliminate the difference in brightness with a small number of light sources, it is conceivable to weaken the relatively strong light in the vicinity of the optical axis by separating the light source from the light guide and sufficiently spreading the light hitting the light guide. However, it is necessary to secure a space around the switch for increasing the distance between the light source and the light guide. Therefore, when the distance between the light source and the light guide is increased, it is difficult to make the periphery of the switch compact. When the space cannot be secured, the distance between the light source and the light guide is reduced. There is an inconvenience that it is not possible to eliminate the difference in brightness by increasing the length.
Japanese Patent Laying-Open No. 2004-214101 (FIG. 4)

  In order to eliminate such inconvenience, the present invention can uniformly emit light over the entire circumference of the switch along the outer periphery of the switch without causing a light / dark difference even with a very small number of light sources, and is compactly configured. An object of the present invention is to provide a light emitting device capable of performing the above.

  In order to achieve such an object, the present invention provides a light-emitting device that emits light in an annular shape along the outer periphery of a switch, and a cylindrical light guide portion whose tip is located on the outer periphery of the switch, and the light guide portion A reflecting portion that is provided in an annular shape along the entire outer periphery of the light guide, and an inner peripheral surface that faces the outer peripheral surface of the light guide portion is inclined in a direction in which the diameter gradually decreases toward the distal end side of the light guide portion; A light source having an optical axis directed parallel to or substantially parallel to the axis of the optical part and projecting to the reflecting part, and formed on the entire periphery of the rear edge surface of the light guiding part, and guided through the reflecting part. A light-diffusing surface portion that diffuses and emits light so that the light of the light source introduced into the light guide portion from the outer peripheral surface of the light portion is visible from the tip end side of the light guide portion.

  According to the present invention, after the light of the light source hits the reflection part, the reflected light from the reflection part is introduced into the light guide part from the outer peripheral surface of the light guide part. The light that enters the light guide unit and reaches the diffuser surface part is diffused and emitted by the diffuser surface part. And the light-scattering surface part of a light emission state permeate | transmits this light guide part from the front-end | tip part side of a light guide part, and is visually recognized. In addition, the said light-diffusing surface part can be formed by performing surface treatments, such as forming a fine uneven surface (wrinkle) on the perimeter of the rear-end edge surface of a light guide part.

  By providing the reflection unit, the light source can direct the optical axis in parallel or substantially parallel to the axis of the light guide unit, so that, for example, when a switch is provided on an operation panel or the like, A light source can be formed on a printed wiring board or the like facing the back side of the panel to make it compact.

  Here, it will be described in more detail until the light from the light source is visually recognized. When the light from the light source hits the reflection portion, the reflection portion has an annular shape, so that the light is guided along the reflection portion in a cylindrical shape. Wrap around the part. At this time, the light from the light source circulates around the light guide and spreads, so that the intensity of light near the optical axis of the light source is weakened and enters the light guide with a small difference in brightness. And the light which entered the inside of a light guide part diffuses in a light-scattering surface part, and the brightness difference of light becomes still smaller.

  Accordingly, the difference in brightness and darkness can be eliminated without increasing the distance between the light source and the light guide unit, and not only light can be emitted uniformly over the entire circumference of the light guide unit, but also a compact configuration can be achieved.

  In the present invention, the reflecting portion is characterized in that at least a portion facing the light source is formed with an extending portion extending from the other portion toward the light source. The extension portion increases the reflection area at the position facing the light source, so that the light from the light source can be received by the extension portion without waste and the amount of light directed toward the peripheral wall surface of the light guide portion can be increased.

  Moreover, as one aspect of the present invention, the light guide part and the reflection part are integrally formed of a transparent resin, and the reflection part has a small diameter side continuously provided on the outer periphery of the tip part of the light guide part. It is characterized by projecting in an annular shape along the entire outer peripheral surface of the light guide portion with a gap.

  By forming the light guide part and the reflection part integrally with a transparent synthetic resin or the like, it is possible to reduce the number of parts, facilitate manufacturing, prevent an increase in manufacturing cost, and form compactly. it can. In addition, for example, when the switch is provided on the operation panel of the equipment, if the operation panel is made of a transparent synthetic resin, the light guide part and the reflection part can be integrally formed on the operation panel, and the manufacturing efficiency can be improved. This can further suppress the increase in the manufacturing cost and the manufacturing cost.

  An embodiment of the present invention will be described with reference to the drawings. 1 is a perspective view of a warm air heater equipped with an operation panel employing the light emitting device of the present embodiment, FIG. 2 is a plan view showing a part of the operation panel of FIG. 1, and FIG. 3 is a line III-III in FIG. Cross-sectional explanatory drawing, FIG. 4 is explanatory drawing which shows the effect | action of the principal part.

  As shown in FIG. 1, an operation panel 2 for performing various operations during operation is provided on the upper part of the hot air heater 1. The operation panel 2 has a plurality of operation switches 4 for performing various operations including a main switch 3 for operating start / end of the hot air heater 1 as shown in part in a plan view in FIG. Is provided. The operation panel 2 is made of a transparent synthetic resin, and is provided with a light-shielding print 5 for display or decoration for guiding the operation of the switches 3 and 4. An annular light emitting unit 6 is provided around the main switch 3. The light emitting unit 6 is formed on a part of the operation panel 2 and exposes the operation panel 2 without performing the printing 5. Then, in response to the ON operation of the main switch 3, the light emitting unit 6 emits light in an annular shape so that the operation of the main switch 3 can be confirmed.

  As shown in FIG. 3, the main switch 3 includes a key top 7 that penetrates the operation panel 2 and exposes an upper end surface thereof, and a contact point that is located immediately below the key top 7 and is operated by a pressing operation of the key top 7 ( And an actuating part 8 having a built-in function (not shown). The key top 7 is elastically supported by a key top plate 9 provided opposite to the back side of the operation panel 2 and is supported so as to be freely pushed. The operating portion 8 is attached to a printed wiring board 10 provided to face the lower side of the key top plate 9.

  The light emitting unit 6 constitutes a part of the light emitting device of the present embodiment. As shown in FIG. 3, the light-emitting device includes a light guide unit 11, a reflection unit 12, and a pair of LEDs 13 that are light sources. The light guide portion 11 is formed in a cylindrical shape along the through hole of the operation panel 2 through which the key top 7 passes, and the tip portion of the light guide portion 11 is the light emitting portion 6. The light guide part 11 has light guide properties by being formed integrally with the operation panel 2. In addition, a light diffusing surface portion 14 is formed on the entire circumference of the lower end edge surface of the light guide portion 11 so that the light introduced into the light guide portion 11 strikes and diffuses and emits light. The light diffusing surface portion 14 is formed with a fine uneven surface on the lower end edge surface of the light guide portion 11 so that light is diffused, and a light emitting state that is visible by the light introduced into the light guide portion 11. Form. The reflecting portion 12 is inclined in a direction of gradually reducing the diameter toward the distal end portion of the light guide portion 11, and is formed along the outer periphery of the light guide portion 11 by forming an annular groove on the back side of the operation panel 2. Has been.

  A pair of LEDs 13 as a light source is provided on the printed wiring board 10 to which the operating portion 8 of the main switch 3 is attached, facing the back side of the operation panel 2. That is, the optical axis of each LED 13 is directed parallel to the axis passing through the center of the light guide 11. The key top 7 of the main switch 3 is connected to the key top plate 9 by a support portion (not shown) that gives elasticity, but the positions other than the support portion are open, and each of the key tops 7 is opened through this open portion. The LED 13 is configured to project light toward the reflecting portion 12. In addition, the reflecting portion 12 at a position facing each LED 13 is provided with an extending portion 15 that extends toward the LED 13 by projecting a part of the back side of the operation panel 2.

  When the main switch 3 is operated and the LED 13 is turned on in response to the operation, as shown in FIG. 4, the light of the LED 13 is first irradiated to the reflecting portion 12, and the reflecting portion 12 transmits the light from the LED 13 to the light guide portion. 11 is reflected toward the outer peripheral surface. Since the reflection part 12 is formed in an annular shape, the light of the LED 13 spreads around the light guide part 11 along the reflection part 12. As a result, light in the vicinity of the optical axis of the LED 13 (that is, a strong portion of the light formed along the contour of the LED 13 itself) is weakened, the optical axis becomes ambiguous, and light with a reduced light-dark difference is guided to the light guide unit. 11 hits the outer surface.

  Next, the light from the reflection unit 12 that has hit the outer surface of the light guide unit 11 enters the light guide unit 11 from the entire outer periphery of the light guide unit 11 because the reflection unit 12 is annular. The light that enters the light guide unit 11 is repeatedly reflected inside the light guide unit 11, and the light that reaches the lower end of the light guide unit 11 is diffused in the light scattering surface unit 14, so that the light scattering surface unit 14 enters a light emitting state. . The diffuse light emission of the light diffusing surface portion 14 further reduces the difference in light and darkness, and a state in which light is emitted uniformly over the entire circumference of the light diffusing surface portion 14 is formed. And the light emission state of the light diffusing surface part 14 permeate | transmits the light guide part 11, and is visually recognized from the light emission part 6 of the said operation panel 2. FIG.

  As described above, according to the light emitting device configured as in the present embodiment, even if the distance between the LED 13 and the light guide unit 11 is relatively short and the number of the LEDs 13 as the light source is extremely small, the light emitting unit 6 is used. Can be emitted uniformly over the entire circumference. Moreover, since the light guide part 11 and the reflection part 12 can be integrally formed in the operation panel 2 made of transparent synthetic resin, an increase in the number of parts can be prevented. In addition, by providing the reflecting section 12, as shown in FIG. 3, the printed wiring board 10 provided on the back side of the operation panel 2 only needs to be mounted with the LEDs 13 facing upward. The LED 13 can be easily attached to the LED.

  In the present embodiment, the example in which the light-emitting device of the present invention is provided on the operation panel 2 of the hot air heater 1 is shown, but the present invention is not limited to this, and the present invention can be easily applied to other devices. The light emitting device of the invention can be employed.

  In the present embodiment, the configuration in which the periphery of the main switch 3 emits light is shown. However, the configuration similar to that in the present embodiment can also be adopted when the periphery of another operation switch 4 is caused to emit light.

  Moreover, in this embodiment, although what used a pair of LED13 as a light source was shown as a most preferable example, LED13 may be single.

The perspective view of a warm air heater provided with the operation panel which employ | adopted the light-emitting device of one Embodiment of this invention. The top view which shows a part of operation panel of FIG. III-III sectional view explanatory drawing of FIG. Explanatory drawing which shows the effect | action of the principal part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Main switch (switch), 11 ... Light guide part, 12 ... Reflection part, 13 ... LED (light source), 14 ... Diffuse surface part, 15 ... Extension part.

Claims (3)

A light-emitting device that emits light in a ring shape along the outer periphery of a switch,
A cylindrical light guide portion whose tip is located on the outer periphery of the switch;
A reflecting portion that is provided in an annular shape along the entire outer periphery of the light guide portion, and an inner peripheral surface facing the outer peripheral surface of the light guide portion is inclined in a direction in which the diameter gradually decreases toward the distal end side of the light guide portion. When,
A light source having an optical axis directed parallel to or substantially parallel to the axis of the light guide unit and projecting on the reflection unit;
The light of the light source formed from the outer peripheral surface of the light guide part through the reflection part to the inside of the light guide part from the front end part side of the light guide part. A light-emitting device comprising: a light-diffusing surface portion that diffuses and emits light so as to be visible.   The light emitting device according to claim 1, wherein the reflecting portion is formed with an extending portion extending from the other portion toward the light source at least in a portion facing the light source.   The light guide part and the reflection part are integrally formed of a transparent resin, and the light guide part is connected to the outer periphery of the distal end of the light guide part with a small gap on the light guide part. The light-emitting device according to claim 1, wherein the light-emitting device is provided so as to project annularly along the entire circumference of the outer peripheral surface.

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