JP2007157384A - Sheet switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin sheet switch wherein uneven luminance caused by a switch contact in a symbol mark is not generated. <P>SOLUTION: This sheet switch 30 has a surface sheet 10 equipped with a movable electrode 16 and a stationary sheet 12 equipped with a stationary electrode 20, and is brought into a conducting state by forcing the movable electrode 16 to contact with the stationary electrode 20 by pressing a switch part 14. A light guide plate 24 is disposed at a position facing the switch part 14 on the back side of the stationary sheet 12, and the stationary sheet 12 having translucency makes light from the light guide plate 24 transmit through it to display the prescribed symbol mark 18 on the switch part 14. The movable electrode 16 and the stationary electrode 20 are structured so as to have translucency not to intercept an optical path from the light guide plate 24 till the symbol mark 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a seat switch, and more particularly to its structure.

  A sheet switch employed in an operation panel such as an electric pot is known as a thin switch having a thickness of about several millimeters. For example, a sheet switch with a movable contact described in Patent Document 1 is composed of a sheet with a movable contact and a circuit board having a central fixed contact and an outer fixed contact on the upper surface, and the outer peripheral lower end of the movable contact is fixed outside. It is configured to abut on the contact and have the top face the central fixed contact. When the top of the sheet is pressed, the sheet is bent, and the movable contact on the lower surface of the top is brought into contact with the center fixed contact to conduct.

  On the other hand, as an illuminated switch, a panel switch for an air conditioner in an automobile and a key switch of a cellular phone are known, and the switch function display is clarified in a dark environment such as at night. For example, the panel switch described in Patent Literature 2 collectively illuminates symbol marks such as characters and figures that display a switch function provided on the surface of the switch knob with an internal bulb light source. Moreover, the key switch of the mobile phone described in Patent Document 3 has an LED arranged on a circuit board directly under the keyboard, and illuminates a symbol mark printed on a transparent key member from the inside.

JP 2002-56746 A Japanese Patent Laid-Open No. 9-231855 JP-A-9-62201

  Switches, which are the operation part of equipment such as in-vehicle air conditioners, require a structure that considers operability and visibility in dark environments such as nighttime, and are required to be compact in a limited space. Is done. When illuminating the symbol mark on the surface of the sheet switch from the inside, there is a problem that the internal switch contact casts a shadow on the symbol mark, resulting in uneven brightness of the symbol mark display.

  It is an object of the present invention to provide a sheet switch capable of preventing the occurrence of uneven brightness of a symbol mark without impairing the original features of the sheet switch that are thin and light when an illumination function is added to the sheet switch. To do.

  The sheet switch of the present invention includes a substrate, a flexible surface sheet that is bonded to the substrate so as to form a switch portion partially located away from the substrate, and the substrate of the switch portion. A movable electrode disposed at a position facing the switch portion, and a fixed electrode disposed on the substrate at a position facing the switch portion, and pressing the switch portion to deform the surface sheet, In the sheet switch in which the movable electrode and the fixed electrode are brought into contact with each other, a light emitting portion that emits light is disposed at a position facing the switch portion on the back side of the substrate, and the substrate is translucent And a predetermined symbol mark is displayed on the switch unit by transmitting light from the light emitting unit, and the movable electrode has translucency.

  Another sheet switch of the present invention includes a substrate, a flexible surface sheet that is bonded to the substrate so as to form a switch portion that is partially spaced from the substrate, and the switch portion. A movable electrode disposed at a position facing the substrate; and a fixed electrode disposed at a position facing the switch portion on the substrate, and deforming the top sheet by pressing the switch portion In the sheet switch in which the movable electrode and the fixed electrode are brought into contact with each other, a light emitting portion that emits light is disposed at a position facing the switch portion on the back side of the substrate, and the substrate is transparent. It has optical properties, transmits light from the light emitting portion, displays a predetermined symbol mark on the switch portion, and is configured such that the movable electrode is disposed at a position avoiding the symbol mark.

  Furthermore, in the sheet switch, the fixed electrode may have a light transmitting property.

  Furthermore, in the sheet switch, the movable electrode and the fixed electrode can be configured to be printed with a light-transmitting conductive ink.

  Furthermore, in the sheet switch, the surface area of the fixed electrode may be larger than the surface area of the movable electrode.

  Further, in the sheet switch, a drawing pattern formed of an opaque conductive ink that is electrically connected to the fixed electrode may be arranged on the substrate.

  Further, in the sheet switch, a lead pattern electrically connected to the fixed electrode is disposed on the substrate, and a width of a portion of the lead pattern electrically connected to the fixed electrode is electrically connected to the fixed electrode. It can be set as the structure longer than the width | variety of the part extended on the opposite side to the side to connect.

  According to the seat switch of the present invention configured as described above, an illumination function can be added without impairing the original features of the sheet switch, which is thin and light, and the shadow of the switch contact provided inside the switch causes the optical path to pass. Since it is not blocked, it is possible to prevent the occurrence of uneven brightness of the symbol mark on the surface portion of the switch.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a main part of the seat switch of the present embodiment. 2 is a cross-sectional view of the sheet switch taken along line AA in FIG. The top sheet 10 is made of a light-transmitting material having flexibility, has a bulging portion formed by embossing, and is attached so as to face the fixed sheet 12 in an outer region excluding the bulging portion. By wearing, a hollow convex part is formed between the fixed sheet 12 and the fixed sheet 12. This bulging portion becomes the switch portion 14. The movable electrode 16 is disposed at a position on the back surface side of the top sheet 10 facing the switch portion 14, while the fixed electrode 20 is disposed at a position facing the switch portion 14 on the fixed sheet 12. As shown in FIG. 2, when the switch portion 14 of the top sheet 10 is pressed from the top to the bottom, that is, toward the fixed sheet 12, the top sheet 10 reverses and moves in the pressing direction. With this deformation movement, the movable electrode 16 on the back surface side of the top sheet 10 moves in the pressing direction, and is brought into conduction by contacting the fixed electrode 20 on the fixed sheet 12. Here, both the movable electrode 16 and the fixed electrode 20 are formed by printing with a translucent material such as transparent conductive ink. In addition, translucency refers to a property that light simply passes through, and includes translucency through which the other side can be seen. For example, if the other side is transparent, such as frosted glass, it cannot be said that it is transparent, but it can be said to have translucency. Further, a double-sided adhesive sheet 22 is used for attaching the top sheet 10 and the fixing sheet 12.

  A light-transmitting portion (hereinafter referred to as a symbol mark) 18 representing a predetermined character or figure for displaying a switch function is printed on the back surface side of the switch portion 14 of the top sheet 10 and its periphery. The portions other than the symbol mark 18 are light-shielding. In this embodiment, the symbol mark 18 is shown in the shape of “A / C”. The fixing sheet 12 is formed of a light-transmitting material, and a light guide plate 24 that emits light is attached to a position facing the switch portion 14 on the back surface side of the fixing sheet 12. The light guide plate 24 guides light from a light source disposed at a distant position and emits light toward the switch unit 14. The light guide plate 24 is a plate made of a transparent material, and light emitted from the light guide plate 24 causes the switch unit 14 to display a predetermined symbol mark 18. Instead of the light guide plate 24, a light diffusing plate that scatters light from a distant light source and emits light toward the switch unit 14 may be employed. Further, instead of the light guide plate 24, a light emitter may be placed directly on this portion. The light emitter may be a planar light emitter formed of a light emitting element such as an EL (electroluminescent) element.

  The light guided and emitted by the light guide plate 24 passes through the fixed sheet 12 and the transparent fixed electrode 20, passes through the hollow convex portion between the top sheet 10 and the fixed sheet 12, and then passes through the transparent movable electrode 16. Then, it reaches the back side of the top sheet 10. And this light permeate | transmits the symbol mark 18 of the back surface side of the surface sheet 10, and is inject | emitted from the sheet switch surface. Since the fixed electrode 20 and the movable electrode 16 are transparent, the characters or figures in the shape of the symbol mark 18 are illuminated and displayed without uneven brightness. Thereby, the switch function indicated by the symbol mark 18 can be clearly and clearly recognized by the visual sense of an external user. As described above, in the present embodiment, since there is no obstacle that blocks the optical path such as the switch contact in the middle of the optical path inside the switch 30, the light source input for illumination is compared with the sheet switch in which the switch contact is opaque. Can be used effectively and power consumption can be saved. Further, since such a configuration does not involve a large-scale specification change of the sheet switch structure, the existing sheet switch can be easily modified, and a sheet switch that eliminates uneven light emission of the symbol mark can be provided at low cost. .

  Another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a plan view showing a sheet switch in which the movable electrode 26 is disposed at a position avoiding the symbol mark 18. The same reference numerals are given to the same parts as those in the above embodiment, and the description will be omitted. An opaque movable electrode 26 is disposed at a position facing the switch part 14 on the back surface side of the top sheet 10, and a fixed electrode 20 is disposed at a position facing the switch part 14 on the fixed sheet 12. The movable electrode 26 is printed and formed on the back side of the top sheet 10 at a position where the light from the light guide plate 24 does not form a shadow on the symbol mark 18, and the fixed electrode 20 is printed and formed using a translucent material such as transparent conductive ink. Has been. The symbol mark 18 has a shape of “A / C”, and two movable electrodes 26 are arranged so as to be substantially parallel to the shape of “/”. And the fixed electrode 20 is arrange | positioned in the position which can be reliably conduct | electrically_connected when it contacts the movable electrode 26. FIG. The portions “A”, “/”, and “C” have translucency, but the movable electrode 26 is disposed in the light-shielding design portion, so that the light emitted from the light guide plate 24 is symbol mark. 18 does not form a shadow of the movable electrode 26. As long as the shape of the movable electrode 26 does not overlap the symbol mark 18, other shapes can be adopted. As described above, in the present embodiment, as the material of the movable electrode 26, an opaque conductive material such as an opaque conductive ink having a higher elongation ratio and a lower conductive resistance than the transparent conductive ink can be selected. This is suitable when a large deformation strain of the movable electrode 26 is assumed, or when it is desired to reduce the conduction resistance of the movable electrode 26.

  FIG. 3 is a plan view showing the main part of the fixed electrode and the lead pattern. The longer the width of the electrically connected portion between the fixed electrode 20 and the fixed electrode lead pattern 28 is, the larger the conduction section is, so the conduction resistance is reduced, and stable conduction of the switch can be ensured. For this reason, in each of the above embodiments, as shown in FIG. 3, the fixed electrode lead pattern 28 is arranged in a T shape to secure an electrical connection portion between the fixed electrode 20 and the fixed electrode lead pattern 28. You may reduce the conduction | electrical_connection resistance in a connection part. The shape of the lead pattern 28 is not limited to the T shape shown in FIG. 3, and the width of the portion of the lead pattern 28 that is electrically connected to the fixed electrode 20 is electrically connected to the fixed electrode 20. Any other shape may be used as long as it is longer than the width of the portion extending in the opposite direction. Further, when the fixed electrode lead pattern 28 is arranged at a position where light to the symbol mark 18 is not blocked, an opaque conductive ink whose conduction resistance is generally small may be used as the lead pattern 28. Such a configuration of the lead pattern 28 is suitable when the fixed electrode 20 is formed of a material having a high conduction resistance such as a transparent conductive ink.

  Further, in each of the above embodiments, the fixed electrode 20 may be disposed at a position where light to the symbol mark 18 is not blocked. In this case, an opaque material that is generally considered to have a low conduction resistance can be used as the material of the fixed electrode 20.

  In the above embodiments, the surface area of the fixed electrode 20 may be larger than the surface area of the movable electrode 16 or 26. In this case, the contact area between the fixed electrode 20 and the movable electrode 16 or 26 can be stably secured, so that the switch can be more reliably connected.

  The top sheet 10 may be divided into a “top sheet” formed of a film material and a “moderation sheet” having a light moderation feeling in the pressing operation feeling of the switch. In this case, it is desirable that the symbol mark 18 and other design portions are printed and formed on the “surface sheet” side, and the movable electrode 16 is disposed on the “moderation sheet” side.

  Further, when the fixed electrode 20 is formed of a translucent material, the light amount of the light guide plate 24 and the light transmission of the symbol mark 18 are transmitted so that the light emission display unevenness of the symbol mark 18 is not recognized by an external user's vision. The degree may be adjusted in advance.

  In each of the above embodiments, the contact continuity type sheet switch of the contact point has been described. However, the sheet switch according to the present invention is based on a resistance type switch that operates when the resistance value between the electrodes reaches a certain value, or the principle of the capacitor. The present invention can be similarly applied to a capacitive switch known as an applied non-contact type switch.

It is a top view which shows the principal part of the sheet switch of this embodiment. It is sectional drawing of the sheet | seat switch in the AA line of FIG. It is a top view which shows the principal part of a fixed electrode and an extraction pattern. It is a top view which shows the principal part of the sheet switch of other embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Surface sheet, 12 Fixed sheet, 14 Switch part, 16, 26 Movable electrode, 18 Symbol mark, 20 Fixed electrode, 22 Double-sided adhesive sheet, 24 Light guide plate, 28 Fixed electrode extraction pattern, 30 Sheet switch.

Claims (7)

A substrate,
A flexible topsheet bonded to the substrate so that a part of the switch portion is located away from the substrate;
A movable electrode disposed at a position facing the substrate of the switch unit;
A fixed electrode disposed on the substrate at a position facing the switch unit;
In the sheet switch that presses the switch part to deform the surface sheet, and brings the movable electrode and the fixed electrode into contact with each other,
At a position facing the switch portion on the back side of the substrate, a light emitting portion that emits light is disposed,
The substrate has translucency, transmits light from the light emitting portion and displays a predetermined symbol mark on the switch portion,
The sheet switch, wherein the movable electrode has translucency. A substrate,
A flexible topsheet bonded to the substrate so that a part of the switch portion is located away from the substrate;
A movable electrode disposed at a position facing the substrate of the switch unit;
A fixed electrode disposed on the substrate at a position facing the switch unit;
In the sheet switch that presses the switch part to deform the surface sheet, and brings the movable electrode and the fixed electrode into contact with each other,
At a position facing the switch portion on the back side of the substrate, a light emitting portion that emits light is disposed,
The substrate has translucency, transmits light from the light emitting portion and displays a predetermined symbol mark on the switch portion,
The sheet switch, wherein the movable electrode is disposed at a position avoiding the symbol mark. The seat switch according to claim 1 or 2,
The sheet switch, wherein the fixed electrode has translucency. The seat switch according to any one of claims 1 to 3,
The sheet switch, wherein the movable electrode and the fixed electrode are formed by printing with a conductive ink having translucency. The seat switch according to any one of claims 1 to 4,
A sheet switch characterized in that a surface area of the fixed electrode is larger than a surface area of the movable electrode. The seat switch according to any one of claims 1 to 5,
The sheet switch according to claim 1, wherein a lead pattern formed of an opaque conductive ink electrically connected to the fixed electrode is disposed on the substrate. The seat switch according to claim 6,
A lead pattern electrically connected to the fixed electrode is disposed on the substrate, and a width of a portion of the lead pattern electrically connected to the fixed electrode is defined as a side electrically connected to the fixed electrode. A seat switch characterized by being longer than the width of the oppositely extending portion.

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