JP5010387B2 - Push button device - Google Patents

Description

  The present invention relates to a push button device including an illumination device that illuminates an operation key input unit provided in a small portable electronic device such as a mobile phone or a PDA (personal digital assistant).

Many conventional cellular phones and the like are provided with an illumination device that illuminates the operation key input unit so that the operation key can be easily input even at night or in a dim place. A conventional push button device will be described with reference to FIG. 5A is a plan view, and FIG. 5B is a schematic cross-sectional view of FIG. As shown in FIG. 5, the operation key 2 is disposed so as to be exposed from the opening 7 provided in the lid 1. Further, the light of the light emitting element 3 provided on the circuit board 5 is irradiated to the operation keys 2 arranged on both sides to illuminate the inside of the operation keys 2 so that the operation keys 2 are easy to see.

  Thus, in addition to the conventional push button device that directly irradiates the operation key 2 with the light from the light emitting element 3, a device using a light guide is disclosed (for example, see Patent Document 1). As shown in FIG. 6, the push button device includes a key sheet 106, a light transmissive circuit board 108, and a light guide 110 formed of a light transmissive material. A rectangular plate-like key sheet 106 in which a plurality of operation keys 107 are integrally formed, a plate-like light guide 110 disposed to face the key sheet 106, and a short side of the light guide 110 The light guide body 110 includes light emitting elements 113 and 114 disposed on the side surfaces, and the light guide 110 has light emitting elements 113 and 114 parallel to the short side direction on both the surface facing the operation unit and the back surface thereof. V-shaped grooves 111 and 112 for reflecting light toward the key sheet 106 are provided.

Japanese Patent Application Laid-Open No. 2002-300258 (page 2-3, FIG. 1)

  However, in the conventional example in which the light of the light emitting element 3 shown in FIG. 5 is directly applied to the operation key 2, the light directly above the light emitting element 3 having the highest luminance is transmitted by the lid 1 in order to reduce the luminance unevenness. Since the operation key 2 is irradiated with light that is shielded and emitted obliquely upward from the light emitting element 3, it is difficult to efficiently increase the luminance even when the light emitting element 3 having high luminance is used. In addition, it is necessary to use a large number of light-emitting elements, which increases costs and increases power consumption.

  In addition, the push button device using the light guide shown in FIG. 6 uses the plate-like light guide 110 having a large area, but light is reflected by the V-shaped grooves 111 and 112 formed on both the front and back surfaces. Therefore, it is difficult to uniformly irradiate the entire key sheet 106, and the light use efficiency is low. Further, since the key sheet 106, the circuit board 108, and the light guide 113 are laminated, there is a problem that it is difficult to reduce the thickness.

(the purpose)
The present invention has been made in view of the above problems, and reduces the number of light emitting elements to be used, efficiently and uniformly illuminates operation keys, and suppresses an increase in power consumption. An object of the present invention is to provide a push button device that can be reduced in price.

In order to solve the above-described problems, a push button device according to the present invention includes a key sheet in which a plurality of operation keys arranged vertically and horizontally are exposed from the opening of the lid, and a lower surface side of the key sheet. A circuit board on which a plurality of key switches are mounted correspondingly, a linear light guide provided between the key sheet and the circuit board and arranged between the operation keys arranged in parallel, and a linear light guide A light-emitting element that is arranged at one or both ends and makes light incident thereon, and the linear light guide has a light scattering portion having light transmittance and light reflectivity on the surface, and is a key sheet for the linear light guide The upper surface on the side and the lower surface on the opposite side are formed in a mirror surface, and the light scattering portions are provided on both side surfaces of the linear light guide, both side surfaces are used as light emission surfaces, and the light scattering portion has a large number of protrusions protruding from the surface. Fine unevenness, which is a dot processed surface made of protrusions, is formed on the light exit surface. And a light scattering portion and the mirror surface portion arranged alternately in each of both side surfaces, further characterized in that the light scattering section is provided at a position corresponding to each of the plurality of operation keys.

  Further, the light scattering portion is characterized in that fine irregularities are formed. The light scattering portion is provided on both side surfaces of the linear light guide, and both side surfaces are light emitting surfaces.

  Further, the upper surface on the key sheet side and the lower surface on the opposite side of the linear light guide are formed as mirror surfaces, and a dot processing surface is formed in the light scattering portion. The dot processing surface of this light scattering portion is characterized by comprising a large number of protrusions protruding from the surface.

  The linear light guide has a substantially trapezoidal cross-sectional shape in which the upper surface side on the key sheet side is a short side and the lower surface on the opposite side is a long side.

  According to the present invention, it is possible to illuminate operation keys efficiently and uniformly, and to suppress an increase in power consumption, and to realize a thin and lightweight push button device at a low price.

  1 and 2 are diagrams illustrating a push button device according to an embodiment of the present invention, FIG. 3 is a diagram illustrating another example of a cross-sectional shape of a linear light guide in the present embodiment, and FIG. 4 is a linear light guide. It is the elements on larger scale which show the other example of a body. Hereinafter, specific embodiments of the push button device of the present invention will be described with reference to FIGS.

  1A and 1B show a main part of a push button device according to an embodiment of the present invention. FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA in FIG. As shown in FIG. 1, the push button device according to the present embodiment includes a circuit board 15, a plurality of key switches 14 arranged on the circuit board 15, a plurality of linear light guides 16, and a linear light guide 16. The light-emitting elements (light-emitting diodes (LEDs) in this embodiment) 13a and 13b that are arranged at both ends of the light-emitting device and incident on light and a plurality of operation keys 12a arranged vertically and horizontally above the key switch 14 are lids. 11 and the key sheet 12 exposed from the opening 18. The linear light guide 16 is provided between the key sheet 12 and the circuit board 15, and is disposed between the operation keys 12a arranged in parallel.

  2A and 2B are diagrams showing the linear light guide 16, FIG. 2A is a perspective view, and FIG. 2B is a schematic partial enlarged view seen from the direction of arrow A in FIG. 2 (c) is a diagram showing an optical path propagating in the schematic partial enlarged view as seen from the direction of arrow B in FIG. 2 (a). As shown in FIG. 2, the linear light guide 16 is a linear light guide that extends in only one direction, and has a quadrangular prism shape in this embodiment. The linear light guide 16 has both end portions 16e and 16f as light incident surfaces, and both longitudinal side surfaces 16c and 16d as light emission surfaces. Light emitting elements 13a and 13b are arranged as light sources in the vicinity of both end portions 16e and 16f of the linear light guide 16 that is a light incident surface, respectively. In addition, as a material of the linear light guide 16, acrylic resin, polycarbonate resin, or the like is used.

  Further, as shown in FIG. 2B, light scattering portions 17a and 17b having light transmissivity and light reflectivity are provided on both side surfaces 16c and 16d, which are light exit surfaces of the linear light guide 16. It has been. Fine irregularities are formed in the light scattering portions 17a and 17b. In the present embodiment, a dot processing surface is formed which includes a large number of protrusions protruding from the surfaces of both side surfaces 16c and 16d. The light scattering portions 17a and 17b are provided over the entire surfaces of both side surfaces 16c and 16d. Yes. Light from the light emitting element 13a that has entered from one end 16e as the light incident surface of the linear light guide 16 is reflected by the light scattering portions 17a and 17b, and the remaining portion is the light exit surface. The light is emitted from both side surfaces 16c and 16d with no luminance unevenness. Thereby, the operation key 12a can be illuminated efficiently and uniformly. Further, since the light guide has a linear shape and is disposed between the operation keys 12a arranged in parallel, a feeling of clicking the operation keys can be obtained.

  Further, as shown in FIG. 2C, the upper surface 16 a on the key sheet side and the lower surface 16 b on the opposite side of the linear light guide 16 are formed in a mirror surface, and serve as a light incident surface of the linear light guide 16. The light from the light emitting element 13a that has entered from one end 16e of the light is repeatedly totally reflected by the upper and lower surfaces 16a and 16b, and propagates inside the linear light guide 16.

  In addition, the optical path of the light from the light emitting element 13b that has entered from the other end 16f as the light entrance surface of the linear light guide 16 is incident from the one end 16e of the linear light guide 16. Since it is the same as the optical path of the light from the light emitting element 13a, the description is omitted.

  FIG. 3 is a diagram illustrating another example of the cross-sectional shape of the linear light guide. As shown in FIG. 3A, the linear light guide 26 has a substantially trapezoidal cross-sectional shape with the upper surface 26a side as a short side and the opposite lower surface 26b as a long side. Light scattering portions are formed on both side surfaces 26c and 26d as light emitting surfaces of the linear light guide 26. Thereby, since both side surfaces 26c and 26d form a slope, the emitted light is directed obliquely upward, and the operation key 12a can be illuminated more efficiently and brightly.

  Further, as shown in FIG. 3B, both side surfaces 36c and 36d as light emission surfaces of the linear light guide are formed into convex curved surfaces depending on the positional relationship between the operation key and the linear light guide. Alternatively, the light scattering portions may be provided by forming both side surfaces 46c and 46d into a concave curved surface. Further, as shown in FIG. 3C, both side surfaces 56c, 56d of the linear light guide are formed in a convex shape on a plurality of planes, or both side surfaces 66c, 66d are formed in a concave shape on a plurality of planes. A part may be provided.

  FIG. 4 shows another example of the linear light guide in the present embodiment. As shown in FIG. 4, the linear light guide 76 has light scattering portions 27a and 27b and mirror surface portions 19a and 19b arranged alternately on both side surfaces 76c and 76d, which are light emission surfaces, and further includes a light guide. In this example, the scattering portions 27a and 27b are provided at positions corresponding to the plurality of operation keys 12a. In the light scattering portions 27a and 27b, a dot processing surface including a large number of concave portions is formed on the surface. Thereby, in the mirror surface portions 19a and 19b, the light is totally reflected and the light scattered from the light scattering portions 27a and 27b is emitted toward the operation key 12a. Thus, it is preferable that the operation keys can be illuminated more efficiently and brightly by providing the light scattering portions 27a and 27b at positions corresponding to the plurality of operation keys 12a.

  As described above, according to the present embodiment, it is possible to efficiently illuminate the operation keys efficiently and uniformly, suppress an increase in power consumption, and realize a thin and lightweight push button device at a low price. In addition, since the light guide extending in one direction is used, the design of the light diffusing portion is facilitated, and uniform light can be emitted from the emission surface. For this reason, it is possible to illuminate uniformly regardless of whether the operation key is close to or away from the end of the linear light guide provided with the light emitting element.

In the present embodiment, an example in which a convex or concave dot processing surface is formed as the light scattering portion has been described. However, the present invention is not limited to this, and various processing such as prisms, grain processing surfaces, printing, and the like are possible. The light scattering portion can be formed by the surface.
Moreover, in this embodiment, although the light-scattering parts 17a and 17b were provided in both side surface 16c, 16d, you may provide in the lower surface 16b. At this time, it is preferable that the light is incident toward the operation key by appropriately adopting the shape of the light guide as shown in FIG.

FIG. 1A is a plan view of a push button device according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA in FIG. It is a figure which shows the linear light guide in embodiment of this invention, FIG. 2 (a) is a perspective view, FIG.2 (b) is the general | schematic partial enlarged view seen from the direction of the arrow A in FIG. FIG. 2 (c) is a schematic partial enlarged view of the optical path propagating through the inside, as viewed from the direction of arrow B in FIG. 2 (a). It is a figure which shows the other example of the cross-sectional shape of the linear light guide in embodiment of this invention. It is a general | schematic fragmentary enlarged view which shows the other example of the pushbutton apparatus in embodiment of this invention. It is a figure which shows the principal part of the pushbutton apparatus in a prior art, Fig.5 (a) is a top view, FIG.5 (b) is BB sectional drawing in Fig.5 (a). It is a perspective view which shows the principal part of the pushbutton apparatus in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Cover body 12 Key sheet 12a Operation key 13a, 13b Light emitting element 14 Key switch 15 Circuit board 16 Linear light guide 16a Upper surface 16b of linear light guide Lower surface 16c, 16d of linear light guide Side surfaces 16e and 16f of the end face 17a and 17b of the linear light guide Light scattering portion 18 Openings 19a and 19b Mirror surface portions 27a and 27b Light scattering portions

Claims (2)

A circuit board on which a plurality of operation keys arranged vertically and horizontally are exposed from the opening of the lid, and provided on the lower surface side of the key sheet, and a plurality of key switches are mounted corresponding to the arrangement positions of the operation keys A linear light guide provided between the key sheet and the circuit board and disposed between the operation keys arranged in parallel, and light disposed at one or both ends of the linear light guide. The linear light guide has a light scattering portion having light transmittance and light reflectivity on the surface, and the upper surface of the linear light guide on the key sheet side and the opposite side. The lower surface is formed in a mirror surface, the light scattering portion is provided on both side surfaces of the linear light guide, the both side surfaces are light emitting surfaces, and the light scattering portion has a number of protrusions protruding from the surface. The light emitting surface is formed with fine irregularities that are dot-processed surfaces made of And said light scattering portion and the mirror surface portion arranged alternately in each of the side surfaces is further push button apparatus being characterized in that provided in a position corresponding to each of said light scattering portion and the plurality of operation keys. 2. The pushbutton according to claim 1, wherein the linear light guide has a substantially trapezoidal cross-sectional shape in which an upper surface side on the key sheet side is a short side and a lower surface on the opposite side is a long side. apparatus.

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