JP2007134080A - Illuminated pushbutton device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illuminated push button switch having high luminance, no luminance unevenness and good pressing feeling.
An inclined portion having a predetermined angle as a refracting portion is provided on the top surface of the operation button or on the top surface and the bottom surface.
[Selection] Figure 3

Description

  The present invention relates to an illumination type push button device applied to various electronic devices such as an illumination type push button switch.

Conventionally, an illuminated push button switch is provided on the operation surface of the device to turn the switch on and off in conjunction with the button press. For example, information corresponding to the button press is stored in the button. This illuminated pushbutton switch has a light source inside and forms a display part that transmits light in the button part, etc., and displays switch information etc. by the light from the light source. Can be done. (For example, see Patent Document 1 to Patent Document 4.)
A conventional illuminated operation button will be described in detail with reference to FIGS.

  5 to 7 show a conventional example 1 in which an LED (light emitting diode) is arranged directly below the operation button and a tact switch is arranged on the side. FIG. 5 is a side view of the illuminated push button switch as viewed from the side, and FIG. 6 is a top view. FIG. 7 is a cross-sectional view taken along the broken line BB in FIG.

  The LED 106 and the tact switch 102 are mounted on the substrate 103. The operation button is composed of two parts, a light shielding unit 101 and a transmission unit 104. The center of the LED 106 and the center of the operation button are arranged on the same axis. A projection shape 105 for pressing the tact switch 102 is formed at the end of the light shielding portion 101 of the operation button. When the operation button is pressed, the projection shape 105 presses the operating range of the tact switch 102, the switch is operated, and the LED is lit or blinks. The transmissive part 104 of the operation button is formed of a diffusing material, or the light incident part and the light emitting part are subjected to texturing, so that light is diffused to reduce luminance unevenness. Further, in order to operate the tact switch 102 without a sense of incongruity even when the right end of the operation button is pressed, fulcrum fulcrums 107, 108a, and 108b are formed in the light shielding portion and the transmission portion of the operation button.

  8 to 10 show a conventional example 2 in which the tact switch is arranged almost directly below the operation button and the LED is arranged on the side. FIG. 8 is a side view of the illuminated push button switch as viewed from the side, and FIG. 9 is a top view. FIG. 10 is a cross-sectional view taken along the broken line CC in FIG.

The LED 116 and the tact switch 112 are mounted on the substrate 113. The surface of the operation button 111 is painted, and the light emitting display unit 114 is cut with a laser. A protrusion 115 for pressing down the tact switch 112 is formed near the lower center of the operation button 111. In order to make the light of the LED 116 reach the light emitting display unit 114, the surface of the button 111 is devised so that the light is diffusely reflected inside the operation button 111 by devising painting or plating.
JP-A-7-326246 JP-A-11-143410 JP 2003-249142 A JP 2004-336168 A

  In the case of Conventional Example 1 in which the LED is arranged directly below the button, sufficient luminance can be obtained, and occurrence of luminance unevenness can be avoided. However, in order to press the switch with the protrusion formed on the end of the button, pressing the part close to the button protrusion requires less force to operate the switch, but the part away from the button protrusion When is pressed, even if there is a special fulcrum, a relatively large force is required to operate the switch. In the worst case, the switch may not be operated.

  Further, in the case of the conventional example 2 in which the switch is arranged almost directly below the button, the force required to operate the switch is almost equal regardless of which part of the button is pressed, and the switching is good. However, since the LED moves away from just below the button, the luminance is greatly reduced unless a light guide is used, and luminance unevenness occurs such that the portion near the LED has high luminance and the portion far from the button has low luminance. When a light guide is used, low luminance and luminance unevenness can be improved, but this leads to an increase in cost. Further, since the operation system has been made thinner in recent years, it is difficult to give the light guide the necessary thickness.

In view of the above object, the illuminated pushbutton device of the present invention forms an inclined portion along the exterior shape on the light exit surface of the light guide,
The light emitting element is disposed at a position where light is refracted in the substantially same direction as the optical axis on the exit surface. An inclined portion having a predetermined angle with respect to the optical axis of the light source may be formed on the light incident surface of the light guide. The switch is disposed almost directly below the light guide.

  As described above, according to the present invention in which the light-reflecting body is provided with a refracting portion that refracts light, even when the LED is not placed directly below, it can appear as if the LED is directly below. It can be applied to an illuminated pushbutton device in which the light source cannot be placed directly below. For example, an illuminated pushbutton switch in which a switch is arranged directly below can realize an illuminated pushbutton switch that does not interfere with switching, has high luminance, and has no luminance unevenness.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a side view showing an embodiment of an illuminated pushbutton switch according to the present invention applied to an operation button of an electronic device or the like, and FIG. 2 is a top view. FIG. 3 shows a cross-sectional view taken along the broken line AA in FIG.

  A tact switch 2 and an LED 6 are mounted on the printed wiring board 3. The operation button 1 is disposed immediately above the tact switch 2, and is attached and fixed to a cover (not shown). The operation button 1 is formed with a projection shape 5 for pressing the tact switch, and the operation button 1, the projection shape 5 and the tact switch 2 are coaxially centered.

  When the operation button 1 is pressed, the projection shape 5 formed on the operation button presses the tact switch, the switch is activated, and the LED 6 is lit or blinks. The operation button 1 has an inclined portion on the top surface according to the external shape of a cover (not shown). Also, the bottom surface has an inclined portion. The light from the LED is refracted twice and guided to the upper surface of the button, with the inclined portion at the bottom as the first refracting portion and the inclined portion at the top as the second refracting portion. Then, in FIG. 3, a virtual image of the LED is displayed at the intersection of the oblique lines in which the light beam emitted from the button is extended inside the button. Therefore, although the LED 6 is located away from the center of the operation button 1, when viewed from the upper surface of the button, the LED 6 looks as if it is directly below the button.

  FIG. 4 is a schematic diagram showing a state of refraction of a light beam emitted from the top surface of the operation button perpendicularly to the wiring board. The inclination angle of the refracting part and the position of the LED can be calculated by the refraction law shown in [Equation 1]. Here, N and N ′ are the refractive index of air and the refractive index of the material used for the operation button 1, respectively.

θ₀ 〜θ₄ 、Ｎ、Ｎ′には［数２］、［数３］、［数４］に示す関係が成り立つ。

The relationships shown in [Equation 2], [Equation 3], and [Equation ₄ ] hold in θ _{0 to} θ ₄ , N, and N ′.

設計変数は天面の傾斜角θ₀ と底面の傾斜角θ₄ である。天面の傾斜角θ₀ は外装の曲面形状に沿って決定されるため、実質的な設計変数は底面の傾斜角θ₄ のみとなる。θ₀ 、θ₄ を決定すると、θ₁ 、θ₂ 、θ₃ 、も順次求まり、底面の鉛直方向とθ₃ の角を成す直線が配線基板と交わる位置にＬＥＤを配置すればよい。すなわち、ＬＥＤの、見た目の位置からのオフセット量ｘは

The design variables are the top surface tilt angle θ ₀ and the bottom surface tilt angle θ ₄ . Since the inclination angle θ _{0 of the} top surface is determined along the curved surface shape of the exterior, the substantial design variable is only the inclination angle θ _{4 of the} bottom surface. When θ ₀ and θ ₄ are determined, θ ₁ , θ ₂ , and θ ₃ are also obtained sequentially, and the LED may be arranged at a position where a straight line that forms an angle of θ ₃ with the vertical direction of the bottom surface intersects the wiring board. That is, the offset amount x of the LED from the apparent position is

となる。

It becomes.

In claim 1, the illumination member is characterized in that an inclined portion is formed only on the top surface of the light guide. In [Equation 3], the inclination angle of the bottom surface is set to θ ₄ = 0. Thus, the present invention can be applied even when the bottom surface does not have an inclined portion. If the bottom of the wiring board and the light guide are close,

と近似してもかまわない。

May be approximated.

As an example, polycarbonate is used as the material of the light guide, and the LED offset amount x is obtained when θ ₀ = 30 °, θ ₄ = 10 °, h ₀ = 3.0, h ₄ = 0.5. The refractive index of polycarbonate is about 1.55 and N ′ = 1.55. The calculation is performed assuming that the refractive index of air is N = 1. From [Equation 2], θ ₁ = 18.8 °, from [Equation 3], θ ₂ = 21.2 °, and from [Equation 4], θ ₃ = 34.1 °, and x = 0.72.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and can be implemented with various changes and improvements. For example, although the embodiment has been described using the operation buttons, the present invention can also be applied to a general lighting unit that does not require a switch when there is another member directly below and the LED cannot be disposed directly below.

Side view showing an embodiment of the present invention The top view which shows the Example of this invention Sectional drawing which shows the Example of this invention Schematic diagram showing the state of refraction Side view showing illuminated pushbutton switch of Conventional Example 1 Top view showing illuminated pushbutton switch of Conventional Example 1 Sectional drawing which shows the illumination type pushbutton switch of the prior art example 1. Side view showing illuminated pushbutton switch of Conventional Example 2 Top view showing illuminated pushbutton switch of Conventional Example 2 Sectional drawing which shows the illumination type pushbutton switch of the prior art example 2.

Explanation of symbols

1 Operation Button 2 Tact Switch 3 Wiring Board 4 Light Emitting Display 5 Projection Shape 6 LED

Claims (3)

In an illuminated pushbutton device having a light emitting element as a light source and a light guide that guides light of the light emitting element to the outside,
An illuminated push button device, wherein a switch is disposed substantially directly below a light guide, and the light emitting element is disposed at a position where light is refracted in a direction substantially the same as the push direction on the exit surface. The illuminated pushbutton device according to claim 1,
An illumination type push button device, wherein a light emitting surface of the light guide is formed with an inclined portion which is not perpendicular to the optical axis of the light source. The illuminated pushbutton device according to claim 2,
An illumination type push button device, wherein an inclined surface that is non-perpendicular to an optical axis of the light source is formed on an incident surface of the light guide.

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