JP2552652Y2 - Cover member for illuminated shield pushbutton switch - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a cover member for an illuminated shield push button switch, in particular, an electromagnetic wave shield coloring layer having a light-shielding property to prevent electromagnetic interference from high-frequency pulses. The present invention relates to a cover member for an illuminated shield push button switch which is useful for telephones, portable telephones, and the like.

[0002]

2. Description of the Related Art As for a cover member for a push button switch,
An illuminated type in which characters and symbols are formed on the top surface of the cover member, or a transparent color layer and a light-shielding colored layer are provided on the entire surface of the cover member so that characters and symbols are transmitted therethrough is known. However, these known push-button switch cover members have no protection device against radio interference caused by high frequency. For this reason, high-frequency radio interference occurs in cover members used for cordless telephones such as in-vehicle telephones and portable telephones, remote control switches, and the like.

[0003]

That is, high frequencies of several hundred MHz to 1 GHz are used for vehicle-mounted telephones and portable telephones, but this must not be affected by other electromagnetic waves. The electronic equipment of these telephones is designed to shield the housing and electronic components to prevent interference from electromagnetic waves, so that it can not affect the telephone or other electronic equipment, but the cover used here The members are no measures and no treatment.

[0004] Therefore, regarding the cover member used for the vehicle-mounted telephone and the portable telephone, the electromagnetic wave due to the electromagnetic wave noise due to the high frequency pulse transmitted from a large number of ICs and LSIs built in the electronic equipment of these telephones. An obstacle has been created, and as the frequency of digital switches in this electronic device has been raised from the order of a few KHz to the order of several hundred MHz in order to improve its processing capability, this electromagnetic interference has become increasingly difficult. Since the number of the cover members is increasing, it is necessary to provide the cover member with a shielding effect.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a cover member having a shielding property which solves such a problem. The cover member is provided above a key top of a cover member formed of a transparent or translucent rubber material. A light-transmitting colored layer is provided, and a light-shielding and conductive light-shielding colored layer is provided on the outer surface of the cover member and on the light-transmitted colored layer. A light section is provided.

That is, the inventor of the present invention has conducted various studies to develop a shield cover member for preventing electromagnetic interference from high-frequency pulses. As a result, the present inventors have found that the cover member is formed of a conventionally known transparent or translucent rubber material. A light-transmissive coloring layer is provided on the key top portion of the cover member, and a light-shielding pigment and a conductivity-imparting agent are added on the outer surface of the cover member and the light-transmissive coloring layer to form a light-shielding conductive layer. When a rubber composition having a property is applied, it is found that this coating layer serves as a light-shielding colored layer that prevents electromagnetic interference from high-frequency pulses as well as light-shielding. By irradiating and partially removing the light-shielding shielding colored layer and giving it a predetermined code shape, it is confirmed that this becomes a shielding cover member. It was completed devised. This will be described in more detail below.

[0007]

The present invention relates to a cover member having a shielding property. As described above, the cover member formed of a transparent or translucent rubber material is provided with a translucent coloring layer above a key top portion. A light-shielding and conductive light-shielding coloring layer is provided on the outer surface of the cover member and the light-transmitting coloring layer, and a light-transmitting portion having a predetermined sign is provided on the light-shielding coloring layer. This is characterized by the fact that the light-shielding colored coloring layer is light-shielding and conductive, so that external light does not enter into the inside of the cover member. It prevents electromagnetic interference caused by high-frequency pulses, so that the built-in light source makes it easy to see characters and symbols such as signs even in dark places. It is useful for example, for telephone.

The cover member of the present invention is shown in FIG. FIG. 1 is a longitudinal sectional view of a shielding member 1 according to the present invention, which includes a key top portion 2, a thin movable portion 3, and a base formed using a transparent or translucent rubber material. A translucent colored layer 7 is provided on the key top portion 2 of the cover member 6 including the portion 4 and the conductive contact portion 5, and a light-shielding shield is provided on the outer surface of the cover member 6 and on the translucent colored layer 7. The light-shielding colored layer 8 is provided with a light-transmitting portion 9.

The cover member 6 itself may be obtained by a conventional method, and is therefore made of silicone rubber such as methylvinylsiloxane, polybutadiene, polyisoprene, terpolymer of ethylene propylene diene, perfluoropropylene. A rubber composition comprising a vinyl polymer and an organic peroxide, such as vinylidene fluoride copolymer, chloroprene rubber, and urethane rubber, or a redox catalyst, sulfur, or sulfur in place of the organic peroxide; A rubber composition to which a catalyst such as a homologue is added,
Alternatively, compression molding, injection molding, transfer molding, or the like may be performed using an addition reaction type siloxane composition from vinyl siloxane, an organohydrogen polysiloxane, and a platinum-based catalyst.

However, since the cover member 6 is preferably made of silicone rubber, it usually has a hardness of 80 or less in IRHD when crosslinked.
It is preferable to use a silicone rubber having a rebound resilience of 40% or more. This may be either the whole made insulative or the whole made conductive, but it is usually good to make the contact part conductive and make the others insulative. It comprises a part 2, a thin movable part 3, a base part 4, and a conductive contact part 5.

In the cover member 1 of the present invention having a shielding property, a translucent colored layer 7 is provided on the upper surface of the key top portion of the conventional cover member 6 because of the illumination type.
Since this translucent colored layer is the one that transmits light first, it is dropped into the key top portion 2 using a dispenser or the like as a liquid material in which a coloring agent is mixed in a rubber material such as silicone rubber. , Should be cured, but this thickness is generally 0.5-to ensure translucency
It should be about 1.0mm.

Further, the cover member 1 of the present invention has a shielding property.
Then, a light-shielding coloring layer 8 is provided on the outer surface of the cover member 6 and on the above-mentioned translucent coloring layer 7, whereby the inside of the cover member 6 is shielded from external light, and Electromagnetic interference from high frequency pulses is prevented. This light-shielding colored layer 8 is made of a rubber material such as silicone rubber or the like, and a colorant such as black, gray, or brown and carbon black, Ketjen black EC, metal powder or the like as a conductivity-imparting agent for making it conductive. It is advisable to use a mixture of these, but since carbon black or Ketjen Black EC etc. have strong light-shielding properties and low-resistance conductivity, methylvinylpolysiloxane with an average degree of polymerization of 100 or more is used. 35 to 45 parts by weight of Ketjen Black EC as a conductivity-imparting agent was added to 100 parts by weight of a silicone rubber compound consisting of, having a volume resistivity of 0.5 Ωcm or less and a plasticity of Williams of 800 or less, preferably 100 It should be ~ 700.

The cover member 1 having a shielding property is required to be provided with a translucent portion 9 because it is of an illuminating type. The light-shielding colored layer may be partially removed by irradiating a laser beam, and a predetermined code portion such as a character or a symbol may be formed here.

The cover member 1 according to the present invention is manufactured by forming a cover member 6 from a rubber material by a conventional method, for example, compression molding, injection molding, transfer molding, or the like. A light-transmitting colored layer 7 is formed from the rubber material described above, and a light-shielding colored layer 8 is applied on the outer surface of the cover member 6 and on the light-transmitted colored layer 7. The light transmitting portion 9 may be provided with a laser beam or the like. However, since it takes time to process the cover member, this may be performed, for example, by the following method.

That is, the cover member 1 having the shielding property
Is manufactured according to the method shown in FIGS.
The shading of the light-shielding colored layer 8, the shaping of the translucent colored layer 7, the shaping of the cover member 6 , and the shaping of the light-transmitting portion 9 may be performed in this order. FIG. 2 is a longitudinal sectional view schematically showing an apparatus for forming a light-shielding colored layer, which comprises a vulcanized conductive rubber sheet 11 and an unvulcanized conductive rubber sheet 12 formed by a light-shielding part forming mold 13, Press and heat molding using 14
This light-shielding colored layer 8 is formed in a mold 13 as shown in FIG.

FIG. 3 is a schematic longitudinal sectional view of an apparatus for forming the translucent colored layer 7, which shows a colorant in the center concave portion of the light-shielding colored layer 8 formed by the method of FIG. A liquid rubber material 15 containing the compound may be dropped and cast through the syringe 16 and the dispenser 17. FIGS. 4 and 5 are longitudinal sectional views showing a method of forming the cover member 6. As shown in FIG. 4, the light shielding shield coloring layer 8 and the translucent coloring layer 7 are formed as shown in FIG. A plate-shaped rubber material 18 may be prepared on a mold 13 to be held, and may be molded by pressing and heating with a mold 19, according to which the light-shielding colored coloring layer 8 and the transparent layer 8 are transparent as shown in FIG. The cover member 6 bonded and integrated with the light colored layer 7 is obtained.

FIG. 6 shows this light-shielding colored layer 8
FIG. 2 is a longitudinal sectional view of a method of forming a light transmitting portion 9. In this case, when a laser beam 21 is irradiated from a laser marker 20 through a mask 22 from above a light shielding and shielding colored layer 8, The light-shielding colored layer 8 is partially removed by the light 21 to form a light-transmitting portion 9 on which a code portion such as a character or a symbol engraved on the mask 22 is printed, as shown in FIG. As described above, the shield member 1 of the present invention is obtained.

[0018]

Next, embodiments of the present invention will be described. Example Silicone rubber KE 971U [trade name manufactured by Shin-Etsu Chemical Co., Ltd.] 100 parts by weight, vulcanizing agent C-19A / 19B [trade name manufactured by Shin-Etsu Chemical Co., Ltd.] 2.5 parts by weight / 3.0 parts by weight Ketjen Black EC as conductive carbon black (trade name, manufactured by Lion Akzo Co., Ltd.) Vulcanization molding of conductive silicone rubber with a Williams plasticity of 600 obtained by kneading 40 weight by calender roll into a 20 μm thick sheet Then, the unvulcanized conductive silicone rubber described above was passed through a calender roll on the vulcanized conductive rubber sheet to a thickness of 30 μm.
m of the unvulcanized conductive silicone rubber sheet was obtained to obtain a sheet for a light-shielding colored layer.

The sheet for the light-shielding colored layer is cut into a size that can be formed into a shape of a push button switch, placed on an engraving die, and coated with a mold release agent.
The light-shielding colored layer was molded by pressurizing and heating at 140 to 160 ° C. at 0 kgf / cm ² . Then, an addition-reaction type low-temperature curable liquid silicone rubber, KE-1935A / B (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed at a ratio of A / B = 100/100,
100 parts by weight of a colorant for silicone rubber, KE-Colo
2 parts by weight of r.W-KE-Color.MB (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was rotated and mixed at 300 rpm with a blade type stirrer to obtain two kinds of liquid silicone rubber compositions having different hues. After the preparation, this was poured into the central concave portion using a syringe and a dispenser until the thickness became 1 mm, and the mixture was heated and cured at 130 ° C. to form a translucent colored layer.

Next, the silicone rubber composition
A sheet obtained by injection-molding KE1915 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) using an injection molding machine is placed, and heated to 20 kgf / cm ² and 170 ° C. using an embossing die. A cover member composed of a thin movable portion and a base portion was formed as having the above-described light-shielding colored layer and light-transmitting colored layer. It should be noted that the cover member obtained in this manner was coated with N
d: Using a YAG laser marker SL-478J (trade name, manufactured by NEC Corporation), cut out the shape of the letters “AS” and irradiate several pulses of laser light with an energy of 15 Joules through an aluminum-deposited glass mask. As a result, a character-shaped light-transmitting portion is formed here, and since the light-transmitting portion is of an illuminated type, the character can be easily identified even at night and has an electromagnetic wave shielding effect.

[0021]

The present invention relates to a cover member having a shielding property. As described above, the cover member formed of a transparent or translucent rubber material is provided with a translucent coloring layer on the upper surface of the key top portion. A light-shielding and conductive light-shielding colored layer is provided on the outer surface of the cover member and the light-transmitting colored layer, and a light-transmitting portion having a predetermined sign is provided on the light-shielding colored layer. This is characterized by being useful as an illuminating type since the inside of the shielding cover member is shielded from external light by the light-shielding shielding colored layer. Can prevent electromagnetic interference from high-frequency pulses, so that it can be advantageously used for in-vehicle telephones and portable telephones.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a shield cover member of the present invention.

FIG. 2 is a longitudinal sectional view of a molding device for forming a light-shielding colored layer when the cover member of the present invention is manufactured.

FIG. 3 is a vertical cross-sectional view of the light-transmitting colored layer forming apparatus when the cover member of the present invention is manufactured.

FIG. 4 is a longitudinal sectional view of the cover member manufacturing apparatus when manufacturing the shield cover member of the present invention.

FIG. 5 is a vertical cross-sectional view of the inside of a mold during molding of the shielding cover member of the present invention.

FIG. 6 is a vertical cross-sectional view of the light-transmitting portion forming apparatus when manufacturing the shielding member according to the present invention.

[Description of Signs] 1 … cover member of shielding property 2… key top portion 3… thin movable portion 4… base portion 5… conductive contact portion 6 …
Cover member, 7: translucent colored layer,
8: light-shielding colored layer, 9: light-transmitting part,
11 ... vulcanized conductive rubber sheet, 12 ... unvulcanized conductive rubber sheet, 13, 14 ... shading mold, 15 ... rubber material, 16 ... syringe, 17 ... dispenser, 18 ... plate rubber material, 19… embossed mold,
20… Laser marker, 21… Laser light,
22 ... Mask.

Claims (2)

(57) [Scope of request for utility model registration] 1. A push-button switch cover member formed of a transparent or translucent rubber material is provided with a light-transmissive colored layer above the key top portion, and is provided with a light-transmissive outer surface of the push-button switch cover member. A cover for an illuminated shielded push button switch, wherein a light-shielding and conductive light-shielding shielding colored layer is provided on the coloring layer, and a light-transmitting portion having a predetermined sign shape is provided on the light-shielding shielding colored layer. Element. 2. A volume resistivity in which 35 to 45 parts by weight of Ketjen black as a conductivity-imparting agent is added to 100 parts by weight of a silicone rubber compound having a light-shielding colored layer made of methylvinylpolysiloxane having an average degree of polymerization of 100 or more. Rate is
2. The cover member for an illuminated shield type push button switch according to claim 1, wherein the cover member is made of one having a Williams plasticity of 800 or more at 0.5 Ω · cm or less.