Switch device

A switch device is configured by engaging a plurality of switches in a cam section of an operating member in a manner such that a detecting section can detect positions of operation of the operating member based on electric ON/OFF states of the switches. With this arrangement, it is possible to detect the positions of operation of the operating member by only detecting the electric ON/OFF states of the switches wherever the position of operation the operating member may be. Consequently, a switch device that is simple in construction and capable of reliably detecting positions of operation of the operating member can be provided.

TECHNICAL FIELD

The present invention relates to a switch device to be used in control sections of various electronic equipment.

BACKGROUND ART

In association with the recent trend toward diversification and enhanced functionality of various electronic equipment such as video, audio and air-conditioning equipment, there are an increasing number of devices in which a desired function is selected among a variety of functions by turning a switch device to a particular position among several positions. A description of a conventional switch device of this type will be given referring toFIG. 8andFIG. 9.

FIG. 8is a perspective view of a conventional switch device. A plurality of wiring patterns (not shown) are formed on the top and rear surfaces of wiring board1(hereinafter “board”). Operating member2is rotatably mounted on the top surface of board1. Roughly disc-shaped knob2A is formed on the top surface of operating member2while two or more protruding portions3A,3B,3C, etc., are formed on the outer periphery of the lower part roughly in the form of a gear.

Also, switch10has lever4and lever4protrudes in a swingable manner from case5made of an insulating resin. Swinging motion of lever4around fulcrum4A causes a movable contact (not shown) to move into contact with fixed contacts (not shown). Terminals6A,6B,6C are provided for outputting electrical signals from the switch10.

Switch10is laid on the top surface of board1in a manner such that lever4engages protruding portions3A,3B,3C, etc., of operating member2. Also, terminals6A,6B,6C are soldered to predetermined wiring patterns and connected with detecting section7composed of electronic components including a microcomputer.

The switch device configured as described above is mounted in electronic equipment in a manner such that knob2A of operating member2is disposed in the control section on the front surface of the equipment. And the wiring patterns on board1are electrically connected to the electronic circuits of the equipment through a connector and the like.

Operation of the switch device having the above configuration will be described with reference to fragmentary plan views inFIG. 9AtoFIG. 9C. In order to switch between functions of the equipment, knob2A is rotated clockwise by 45°, for example, from the position shown inFIG. 9A. By this rotating operation, operating member2is rotated as shown inFIG. 9Band protruding portion3B pushes lever4of switch10and lever4swings from the neutral position to the left around fulcrum4A. With this operation, movable contacts housed inside case5are moved into or out of contact with fixed contacts, and terminals6A,6B, for example, output the electric signals to detecting section7and the function of the equipment is switched.

When knob2A is further rotated clockwise by 45° after protruding portion3B is detached from lever4and lever4temporarily returns to the neutral position, lever4is pushed by protruding portion3C to swing again to the left, and the second electric signal is output from terminals6A,6B to detecting section7. Detecting section7detects the electric signal from terminals6A,6B. Detecting section7detects the position of operation of operating member2in a manner such that, when an electric signal is output once, detecting section7detects that operating member2is rotated clockwise by 45°, and when electric signals are output twice, detecting section7detects that the operating member2is rotated by 90°, and stores the information.

Conversely, when knob2A is rotated counterclockwise as shown inFIG. 9Cfrom the position inFIG. 9A, operating member2is rotated counterclockwise and protruding portion3A pushes lever4. Since lever4swings to the right as a result of this operation, terminals6A,6C output an electric signal to detecting section7. Detecting section7detects the electric signal and determines that operating member2is rotated counterclockwise by 45° and stores the information.

That is, depending on whether the pair of terminals6A,6B or the pair of terminals6A,6C of switch10output the signal, detecting section7determines the direction of rotation of operating member2. Also, detecting section7determines the angle of rotation based on how many times electric signals are output and stores the information. This type of switch device is disclosed in Japanese Patent Unexamined Publication No. 2001-236861, for example.

In the above-described conventional switch, however, detecting section7has always to store the information on how many times knob2A of operating member2is rotated in which direction. Also, when knob2A is rotated under a state in which the power of the equipment is not on and no power is supplied to detecting section7, a problem occurs. That is, when the power is turned on next, the position of operation as stored in detecting section7does not agree with the actual position of operation of knob2A. As a result, it becomes necessary to provide some sort of detecting means or to provide correcting means in the electronic circuit, thereby increasing the complexity and cost of the switch device.

SUMMARY OF THE INVENTION

A switch device of the present invention includes an operating member having a cam section which is provided with a protruding portion, a plurality of switches, and a detecting section. The switches engage the cam section and the detecting section detects the position of operation of the operating member based on the electric ON/OFF states of the switches.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a perspective view of a switch device in an exemplary embodiment of the present invention.FIG. 2AtoFIG. 2Dare fragmentary plan views of the switch device ofFIG. 1. A plurality of wiring patterns (not shown) are formed on the top and rear surfaces of wiring board11(hereinafter “board”). Operating member12is mounted on the top surface of board11in a rotatable manner. Roughly disc-shaped knob (or user-operable member)12A is formed on the upper part of operating member12, and cam section12B having protruding portion13on the outer periphery is formed on the lower part of operating member12, Coupling section28is interposed between knob12A and can section12B. Protruding portion13is provided over a predetermined angle with respect to the axis of rotation of operating member12. Switch20has lever141and lever141projects in a swingable manner out of case15made of an insulating resin. Swinging motion of lever141around fulcrum14A causes a movable contact (not shown) housed inside case15to be moved into or out of contact with fixed contacts (not shown). Switch20outputs a resultant electric signal via terminals16A,16B. Switch20is laid on the top surface of board11in a manner such that lever141engages cam section12B of operating member12. Also, terminals16A,16B are soldered to predetermined wiring patterns on board11and connected to detecting section27composed of electronic components including a microcomputer. Switch21is configured in a manner similar to switch20and has lever142and terminals16C,16D. Switch20and switch21are disposed 90° apart from each other with respect to the axis of rotation of operating member12. The structure of each of the switches20,21is disclosed in Japanese Patent Unexamined Publication No. H10-21788, for example.

The switch device configured as described above is mounted on electronic equipment with knob12A of operating member12disposed in a control section of the front panel of the electronic equipment, and the wiring patterns on board11are electrically connected to electronic circuitry of the electronic equipment via a connector and the like. In mounting the switch device, as coupling section28is provided, it suffices to make a small hole in the electronic equipment.

Next, the operation of the switch device as configured above will be described referring toFIG. 2AtoFIG. 2D.

FIG. 2Aillustrates a state in which protruding portion13of operating member12is neither engaging lever141of switch20nor lever142of switch21. As switches20,21are in the OFF state, terminals16A,16B,16C,16D do not output electric signal to detecting section27.

In order to switch over equipment function from this state, knob12A is rotated clockwise by 90° as shown inFIG. 2B. With this operation, cam section12B is rotated, protruding portion13pushes lever141of switch20, the movable contact housed inside case15is brought into contact with fixed contacts and switch20is turned on. Terminals16A,16B output an electric signal of this state to detecting section27and the function of the equipment is switched. In this state, as switch21is not engaging protruding portion13, switch21is not outputting an electric signal to detecting section27.

Subsequently, as shown inFIG. 2C, knob12A is further rotated clockwise by 90°. With this operation, cam section12B is rotated, protruding portion13pushes lever141of switch21and switch21is also turned on. As a result, each of switches20,21outputs an electric signal to detecting section27.

Additionally, knob12A is further rotated clockwise by 90°, namely, to a position of 270° from the state ofFIG. 2A. As shown inFIG. 2D, while lever142remains pushed by protruding portion13, lever141becomes free from protruding portion13. Switch20is thus in the OFF state and switch21is in the ON state. Electric signals of the states are output to detecting section27.

In summary, in the state ofFIG. 2A, both switches are in the OFF state while in the state ofFIG. 2Bin which the operating member is rotated by 90°, only switch20is in the ON state. In the state of 180° rotation ofFIG. 2C, both switches are in the ON state and, in the state of 270° rotation ofFIG. 2D, only switch21is in the ON state. In this way, switches20,21are made to engage cam section12B of operating member12and detecting section27detects the position of operation of operating member12depending on the electric ON or OFF state of these two switches.

As the electric ON or OFF state of switches20,21depends on the position of operation of operating member12in this way, there is no need for detecting section27to store the information on how far operating member12is rotated in which direction. Also, even when operating member12is rotated in a state in which the power of the equipment is switched OFF and no power is being supplied to detecting section27, no trouble occurs. That is, when the power is switched on next time, detecting section27immediately detects the position of rotation of operating member12from the electric ON or OFF state of switches20,21.

As is described above, in this configuration, switches20,21engage cam section12B of operating member12and detecting section27detects the position of operation of operating member12based on the electric the ON or OFF state of switches20,21. By configuring the switch device in this way, position of operation of operating member12can be detected by only detecting electric ON or OFF state of switches20,21wherever the position of operation of operating member12may be. Consequently, a switch device is obtainable that is simple in structure and is capable of reliably detecting the position of operation of operating member12.

In the above description, switches20,21are disposed to the right and in the lower part of operating member12at an angle of 90° from each other relative to the axis of rotation of operating member12. A description is also made of a configuration in which operating member12can be rotated to four positions in increments of 90°. In addition to this, a switch device may also be configured by changing the locations of the switches, the location and angle of providing protruding portion13, or disposing many switches in order that various positions of rotation of operating member12can be detected.

Next, another exemplary embodiment of the present invention will be described. Structural elements that are the same as those in the above-described configuration are given the same reference numerals and detailed description is omitted.

FIG. 3is a perspective view of another switch device in the exemplary embodiment of the present invention.FIG. 4AtoFIG. 4Eare fragmentary plan views of the switch device ofFIG. 3. Cam section12C having a plurality of protruding portions13A,13B on the outer periphery is formed under operating member12. Protruding portions13A,13B are provided over respective predetermined angles with respect to the axis of rotation of operating member12. Switch22has lever171, and lever171projects in a swingable manner out of case18made of an insulating resin. By a swinging motion of lever171around fulcrum17A, a movable contact (not shown) housed inside case18is brought into contact with or detached from a plurality of fixed contacts (not shown). Switch22outputs respective electric signals via terminals19A,19B,19C.

Switch22is laid on the top surface of board11in a manner such that lever17engages cam section12C of operating member12. Terminals19A,19B,19C are soldered to predetermined wiring patterns on board11and connected to detecting section27. Switch23is configured in the same manner as switch22and has lever172and terminals19D,19E,19F. Switch22and switch23are disposed at 180° from each other relative to the axis of rotation of operating member12. The configuration of switches22,23is disclosed in Japanese Patent Unexamined Publication No. H11-260201, for example.

The switch device configured as described above is mounted on electronic equipment with knob12A of operating member12disposed in a control section on the front panel of the electronic equipment, and the wiring patterns on board11are electrically connected to electronic circuitry of the electronic equipment via a connector and the like.

Next, operation of the switch device having the above configuration will be described referring toFIG. 4AtoFIG. 4E.

FIG. 4Aillustrates a state in which protruding portions13A,13B of operating member12are engaging neither lever171of switch22nor lever172of switch23. As switches22,23are in the OFF state, terminals19A,19B,19C,19E,19F are not outputting an electric signal to detecting section27.

In order to switch over function of the electronic equipment from this state, knob12A is rotated clockwise by 30° as shown inFIG. 4B. With this operation, operating member12is rotated, protruding portion13A pushes lever171, lever171swings downwardly from the neutral position, and terminals19A,19B of switch22become mutually conducting, namely in the ON state. An electric signal of this state is output to detecting section27and the function of the equipment is switched. In this state, as switch23is not engaging protruding portion13B, switch23does not output an electric signal to detecting section27.

Next, knob12A is further rotated clockwise by 30° as shown inFIG. 4C. With this operation, operating member12is rotated, protruding portion13B pushes lever172, lever172swings upward from the neutral position and terminals19D,19E of switch23also become mutually conducting. As a result, both terminals19A,19B of switch22and terminals19D,19E of switch23output electric signals to detecting section27.

FIG. 4Dshows a state in which knob12A is rotated counterclockwise by 30° from the position shown inFIG. 4A. In this state, protruding portion13B pushes lever171, lever171swings upward from the neutral position and terminals19A,19B of switch22become mutually conducting. As a result, switch22outputs an electric signal to detecting section27and the function of the equipment is switched. Here, in this state, as switch23is not engaging protruding portion13A, switch23does not output an electric signal to detecting section27.

FIG. 4Eshows a state in which operating member12is further rotated counterclockwise by 30° from this state. In this state, protruding portion13A pushes lever172, lever172swings downward from the neutral position and terminals19D,19F also become mutually conducting. As a result, terminals19A,19C of switch22and terminals19D,19F of switch23output electric signals to detecting section27.

In summary, operating member12has cam section12C that includes a plurality of protruding portions13A,13B. And, depending on the direction of swinging of lever171, switch22outputs an electric signal from either terminals19A,19B or terminals19A,19C. Similarly, depending on the direction of swinging of lever172, switch23outputs an electric signal from either terminals19D,19E or terminals19D,19F. By employing this configuration, a plurality of electric ON/OFF states can be obtained.

Accordingly, in this configuration, five operating positions can be detected by using two switches22,23as shown inFIG. 4AtoFIG. 4E.

In this configuration, as described above, operating member12has protruding portions13A,13B, and switches22,23output signals of a plurality of electric ON/OFF states. With this, many positions of operation of operating member12can be detected with a small number of switches. Accordingly, a switch device with which an operating member can be set at various positions of rotation is provided at a low cost.

In the above description, switches22,23are disposed on the right and left of operating member12at an angle of 180° from each other relative to the axis of rotation of operating member12. And a description is given of a configuration in which operating member12is rotated to four positions in increments of 30°. In addition to this, a switch device may also be configured by changing the location of switches, the location and angle of providing protruding portions13A,13B, or further disposing many switches in order that various positions of rotation of operating member12can be detected.

Also, a description is given only of a configuration in which operating member12is rotated. In addition to this, a switch device may also be configured with operating member12D provided with a plurality of protruding portions13C as shown inFIG. 5and movable in a straight line and switches22,23that engage protruding portion13C to thereby detect various positions of operation of operating member12D.

Also, a description is given of a configuration in which a cam section having protruding portions13,13A,13B are formed on the lower outer periphery of operating member12. In addition to this, depending on the mode of operation or shape of operating member12, cam sections12B may be formed at different locations of knob12A such as on the lower part or on the inner surface as illustrated inFIG. 6andFIG. 7.

As described above, a switch device is obtainable that is simple in structure and that can reliably detect positions of operation of the operating member according to the present invention.