JP2008191429A - Operation unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation unit capable of improving luminance by optimizing the position of a light guide sheet with respect to a light source. <P>SOLUTION: A contact sheet 12 is arranged on a substrate 11. The light guide sheet 14 is arranged via a spacer 13 on the contact sheet 12. A light source unit 15 is arranged near an end surface B of the light guide sheet 14. A light emission diode (LED) 151 which is the light source is mounted within the light source unit 15. The spacer 13 is provided in order to align the positions of the light emission center of the light emission diode 151 which is the light source and the center of the thickness direction of the light guide sheet 14. The thickness thereof is set at the thickness sufficient for aligning the light emission center of the light emission diode 151 and the position of the center in the thickness direction of the light guide sheet 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an operation unit arranged in an operation area of a mobile terminal device such as a mobile phone.

2. Description of the Related Art Conventionally, a planar light source that supplies light from the back side of a liquid crystal display panel toward the display surface side, for example, a backlight device, is known as a lighting device for a display device, mainly a liquid crystal display device. An example of such a backlight device is disclosed in Patent Document 1. As disclosed in Patent Document 1, the thickness of the light-emitting diode that is the light source of the backlight device is substantially equal to or greater than the thickness of the wiring board.
JP 2003-298119 A

  In recent years, a light guide sheet has been developed to emit light in an operation region of a mobile terminal device such as a mobile phone by using the planar light source as described above. Since this light guide sheet is disposed on the operation area of the portable terminal device, it is necessary to be flexible in order to ensure the user's operation, and the thickness thereof is also thin. Since this light guide sheet is thinner than the light emitting diode as a light source, the position of the light guide sheet relative to the light emitting diode is optimized in order to efficiently guide the light from the light emitting diode and improve the luminance. There is a need.

  This invention is made | formed in view of this point, and it aims at providing the operation unit which can improve the brightness | luminance by optimizing the position of the light guide sheet with respect to a light source.

  The operation unit of the present invention includes a base body having an operation area, a main surface and an end face, a light guide sheet disposed on the base body directly or via a predetermined sheet, and in the vicinity of the end face of the light guide sheet. A light source disposed, a spacer disposed between the light guide sheet and the base, and a spacer having a thickness sufficient to align the light emission center of the light source and the center of the light guide sheet in the thickness direction; It is characterized by comprising.

  According to this configuration, since the light emission center of the light source and the center of the light guide sheet in the thickness direction are aligned, light from the light source can be efficiently incident on the light guide sheet. Thereby, since the light from the light source can be efficiently used for illumination of the light emitting area, the luminance of the light emitting area can be improved.

  In the operation unit of the present invention, it is preferable that the spacer is made of a light transmitting material (for example, a transparent material). In this case, it is preferable that the position of the light emission center of the light source and the position of the center in the thickness of the light guide sheet and the spacer are matched.

  In the operation unit of the present invention, the spacer has an inclined surface whose thickness decreases toward the traveling direction of light from the light source, and is formed between the light guide sheet and the inclined surface in a cross-sectional view. The angle is preferably 30 ° or more.

  The operation unit of the present invention includes a base body having an operation area, a main surface and an end face, a light guide sheet disposed on the base body directly or via a predetermined sheet, and in the vicinity of the end face of the light guide sheet. A light source disposed, a spacer disposed between the light guide sheet and the base, and a spacer having a thickness sufficient to align the light emission center of the light source and the center of the light guide sheet in the thickness direction; Therefore, it is possible to optimize the position of the light guide sheet with respect to the light source and improve the luminance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing an operation unit according to an embodiment of the present invention. The operation unit shown in FIG. 1 includes a base body 11 having an operation area. There is no particular limitation on the configuration of the operation area of the base 11. A contact sheet 12 is disposed on the base 11. The contact sheet 12 is made of a plastic material such as PET (polyethylene terephthalate) resin. Note that the contact sheet 12 may not be provided. In this case, the spacer 13 is provided directly on the base 11.

  A light guide sheet 14 is disposed on the contact sheet 12 via a spacer 13. That is, the spacer 13 is disposed between the light guide sheet 14 and the base body 11 via the contact sheet 12. The light guide sheet 14 has a main surface A and an end surface B, and is made of a flexible material such as plastic. Specifically, the light guide sheet 14 is made of polyurethane resin, PET (polyethylene terephthalate) resin, PEN (polyethylene naphthalate) resin, silicone resin, polyolefin resin, acrylic resin, or the like. A light emitting region (not shown) made of a light reflecting material is provided on the light guide sheet 14.

  In the vicinity of the end face B of the light guide sheet 14, the light source unit 15 is disposed. In the light source unit 15, a light emitting diode (LED) 151 as a light source is attached. The light guide sheet 14 needs to be thin in order to reliably perform an operation in the operation area (for example, pressing a button). For this reason, the thickness of the light guide sheet 14 is thinner than the thickness of the light source unit 15.

  The light emitted from the light emitting diode 151 in the light source unit 15 enters from the end surface B of the light guide sheet 14 and guides the light in the light guide sheet 14. The light guided in the light guide sheet 14 is emitted to the outside diffused in the light emitting region provided on the main surface A of the light guide sheet 14 (the main surface opposite to the base body 11).

  The spacer 13 is provided to align the light emission center of the light emitting diode 151 as a light source and the center of the light guide sheet 14 in the thickness direction, and the thickness thereof corresponds to the light emission center of the light emitting diode 151 and the light guide sheet. 14 is set to a thickness sufficient to align the center position in the thickness direction. Therefore, the thickness of the spacer 13 is appropriately set in consideration of the thickness of the light guide sheet 14 and the position of the light emission center of the light emitting diode 151 on the substrate 11. The spacer 13 is set to white. Thereby, light can be reflected efficiently and light can be efficiently guided into the light guide sheet 14. In this case, examples of the material of the spacer 13 include acrylic resin, PET resin, silicone resin, and ABS resin.

  In the operation unit having the above configuration, the light emission center of the light emitting diode 151 and the center of the light guide sheet 14 in the thickness direction are aligned by the spacer 13, so that the light from the light emitting diode 151 can be efficiently transmitted. 14. Thereby, since the light from the light emitting diode 151 can be efficiently used for illumination of the light emitting region, the luminance of the light emitting region can be improved.

  When the spacer 13 aligns the light emission center of the light emitting diode 151 and the center of the light guide sheet 14 in the thickness direction, the position of the light emission center of the light emitting diode 151 and the center position in the thickness of the light guide sheet 14 and the spacer. You may comprise so that can be matched. That is, as shown in FIG. 2A, the light emission center of the light emitting diode 151 may be aligned with the center of the total thickness of the light guide sheet 14 and the transparent spacer 16. Specifically, as shown in FIG. 2B, the light guide sheet 14 is opposed to the light source unit 15 with the end face of the transparent spacer 16 that transmits light flush with the light guide unit 14, The center X in the thickness direction of the transparent spacer 16 and the light emission center of the light emitting diode 151 are aligned.

  Even in this case, the thickness of the spacer 16 is set to a thickness sufficient to align the position with the light emission center of the light emitting diode 151. Therefore, the thickness of the spacer 16 is appropriately set in consideration of the thickness of the light guide sheet 14 and the position of the light emission center of the light emitting diode 151 on the substrate 11. The spacer 16 is made of a transparent material. Thereby, it can be made to function as a light guide integrally with the light guide sheet 14. In this case, examples of the material of the spacer 16 include the same material as the light guide sheet 14 and ABS resin.

  About the spacer 16, it is preferable to have the slope 16a from which the thickness becomes thin toward the advancing direction of the light from the light emitting diode 151. FIG. By providing the inclined surface 16a in this manner, the light guided in the spacer 16 can be guided in the light guide sheet 14 and effectively used for light emission in the light emitting region without being emitted to the outside.

  Here, the influence on the luminance of the angle θ formed between the light guide sheet 14 and the inclined surface 16a in a cross-sectional view shown in FIG. 2B will be described. This effect was determined by a ray tracing simulation with ZEMAX (registered trademark) -EE. Specifically, a light guide sheet having a thickness of 0.2 mm, a diffusion diameter of 2.25 mm and a diffusion probability of 0.15 in 3 × 7 rows is used, and θ in FIG. Each of the spacers 16 having a thickness of 0.25 mm, which is between .degree. And 90.degree., Is emitted from the light emitting region when light is incident on the end face of the light guide sheet + spacer from the light source as shown in FIG. The brightness of the light was examined. At this time, with the end faces of the light guide sheet and the spacer being flush with each other, the light source unit was opposed to the light source unit, and the center of the light guide sheet and the spacer in the thickness direction was aligned with the light emission center of the light source. As a light source, two white LEDs NESW020A (manufactured by Nichia Corporation) were used, a current of 5 mA (10 mA in total) was passed per lamp (0.25 lumen per lamp), and the number of light beams was 100,000. It was. The result is shown in FIG.

For comparison, the brightness of the light without the spacer was also examined and found to be 45 cd / m ² . As can be seen from FIG. 3, if the angle θ formed between the light guide sheet 14 and the inclined surface 16a is 30 ° or more, the light guided in the spacer is guided in the light guide sheet without being emitted to the outside. The light can be used effectively for light emission in the light emitting region, and the luminance is improved.

  In the operation unit according to the present invention, as shown in FIG. 4, a spacer 13 is disposed between the contact sheet 12 and the light guide sheet 14, and the spacer 13 is joined to the contact sheet 12 and the light guide sheet 14. Thus, it is possible to prevent the light guide sheet 14 from being displaced. Thereby, the brightness | luminance improvement in an operation unit can be aimed at stably. In this case, the spacer 13 and the light guide sheet 14 are joined by the adhesive material 17, and the spacer 13 and the contact sheet 12 are joined by the adhesive material 18. At this time, the adhesive material 17 is appropriately selected depending on the material of the light guide sheet 14. For example, when the light guide sheet 14 is made of a silicone resin, a silicone adhesive is used, and when the light guide sheet 14 is made of a urethane resin, an acrylic adhesive is used. On the other hand, it is preferable to use an acrylic adhesive material for the adhesive material 18.

  The present invention is not limited to the above embodiment, and can be implemented with various modifications. For example, the configuration of the operation region in the substrate, the dimensions of each part, the material, and the like can be set as appropriate without departing from the effects of the present invention. Other modifications may be made as appropriate without departing from the scope of the object of the present invention.

It is a figure which shows the operation unit which concerns on embodiment of this invention. It is a side view which shows the other example of the operation unit which concerns on embodiment of this invention, (a) is a side view, (b) is the elements on larger scale of (a). It is a figure which shows the relationship between the angle (theta) of the slope of a spacer, and a brightness | luminance. It is the elements on larger scale which show the other example of the operation unit which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Base body 12 Contact sheet 13, 16 Spacer 14 Light guide sheet 15 Light source unit 16a Slope 17, 18 Adhesive material 151 Light emitting diode

Claims (4)

  A base having an operation area; a light guide sheet having a main surface and an end face; and disposed on the base directly or via a predetermined sheet; a light source disposed in the vicinity of the end face of the light guide sheet; A spacer disposed between the light guide sheet and the substrate and having a thickness sufficient to align the light emission center of the light source and the center of the light guide sheet in the thickness direction. Operation unit to perform.   The operation unit according to claim 1, wherein the spacer is made of a light transmitting material.   The operation unit according to claim 2, wherein the position of the light emission center of the light source and the position of the center in the thickness of the light guide sheet and the spacer are matched.   The spacer has an inclined surface whose thickness decreases toward the traveling direction of light from the light source, and an angle formed between the light guide sheet and the inclined surface in a sectional view is 30 ° or more. The operation unit according to claim 2 or claim 3, wherein

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