The present application claims benefit of priority under 35 U.S.C. §§120, 365 to the previously filed Japanese Patent Application No. JP2014-055607 with a priority date of Mar. 18, 2014, which is incorporated by reference herein.
1. Technical Field
The present invention relates to keyboard devices in general, and particularly to a keyboard device used in an electronic apparatus.
2. Description of Related Art
A keyboard device used in an electronic apparatus such as a laptop personal computer (laptop PC) is normally equipped with a base plate, a membrane sheet provided on the upper or lower surface of the base plate, and a key top vertically movably arranged on the upper surface side of the base plate by a pantograph. In such a keyboard device, the corresponding signal is output to a key depressed by making contacting/separating action of the contact of the membrane sheet when the key top is depressed. When the depression of the key top is released, the key top is reset to its original position by the elastic force of a rubber dome (elastic member) provided inside.
The keyboard device generates a suitable repulsive force (or biasing force) when a user depresses the key top with a configuration based on the pantograph and the rubber dome and realizes high usability. To make a thinner keyboard device is relatively difficult because of the usage of rubber domes. For one prior art thin keyboard design, an actuator is placed thereinside and a haptic feedback (or vibration) is provided when a key is depressed. One problem with this thin keyboard design is that vibration is different in touch from the “click” of a key, and the usability is degraded with no suitable repulsive force. Consequently, it would be desirable to provide an improved thin keyboard design.
In accordance with a preferred embodiment of the present invention, a keyboard device includes a base, a key top, a film actuator, a position sensor, and a controller. The key top is movably arranged on the upper surface side of the base. Disposed between the base and the key top, the film actuator bends according to an applied voltage. Also disposed between the base and the key top, the position sensor detects a position of the key top. The controller applies a voltage to the film actuator in order to generate a repulsive force corresponding to the position of the key top detected by the IC position sensor.
All features and advantages of the present disclosure will become apparent in the following detailed written description.
The disclosure itself, as well as a preferred mode of use, further objects, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
A keyboard device, a push button device and an electronic apparatus according to the present invention will hereinafter be described in detail based on the accompanying drawings. It will be readily understood that the components of the present invention, as generally illustrated in the figures of the present specification, may be arranged and designed widely in various ways in a variety of different configurations. Thus, the following more detailed description of the embodiments of the device, system and method of the present invention is not intended to limit the scope of the present invention as claimed, but is merely representative of one example of the selected embodiment of the present invention, and is merely illustrative of the selected embodiment related to the device, system and method without inconsistency with the present invention as claimed in the present specification. One skilled in the related art will recognize that the present invention can be practiced even without one or more of the specific details or even with other methods, components and materials. Incidentally, the present invention is not limited by this embodiment. Further, the components in the following embodiments include one that can be assumed easily by one skilled in the related art, or the substantially the same one. The following embodiments and modifications may respectively be practiced independently, or parts or all thereof may be practiced in combination.
The display side chassis 12 is provided with a display 18. The display 18 is configured by, for example, a touch panel type liquid crystal display device. The main body side chassis 14 accommodates thereinside a substrate (not shown) equipped with various electronic parts such as a keyboard controller (refer to
The keyboard device 16 is an isolation type keyboard device equipped with a plurality of keys (key switches) 22, and a frame (or isolation frame) 26 that fills a gap surrounding a key top 24 constituting an operation surface of each key 22. Namely, in the keyboard device 16, the frame 26 partitions between the key tops 24 and other adjacent key tops 24, and the partitioned key tops 24 are respectively arranged independently.
The frame 26 is a frame body formed with a plurality of holes through which the key tops 24 of the keys 22 are inserted in a sheet of plate-like member formed of a resin or the like.
The keyboard device 16 is connected to the keyboard controller. When an operator depresses the key top 24, a signal corresponding to the key 22 depressed by making contacting/separating action of the contact of a membrane sheet (not shown) (when the key switch is in a state of ON) is output to the keyboard controller.
In the present embodiment, in order to generate a repulsive force suitable for a user where the key top 24 is depressed while thinning the keyboard device 16, a film actuator is used in the keyboard device 16.
The key top 24 has a surface which serves as an operation surface depressed by the operator upon depressing the key 22. The film actuator 31 applies a repulsive force (biasing force) in the direction to return the key top 24 to its original position when the key top 24 is depressed. Both end sides of the film actuator 31 are fixed to the base plate 34.
In
The position sensor 32 is for detecting the position of the key top 24 and can use the same material as the film actuator 31, for example. When the film actuator is bent, the polarization of the piezoelectric polymer 31a is aligned in direction to generate a polarization potential. It is therefore possible to detect the position of the key top 24 by measuring the potential. When the film actuator is used as the position sensor 32 (hereinafter referred to as a film sensor 32), both end sides of the film sensor 32 are fixed to the base plate 34, and the position (height) of the key top 24 is set to correspond to the bending of the film sensor 32 one on one. Incidentally, although a description has been made about the example in which the film sensor is used as the position sensor 32, an electrostatic sensor or a distance sensor may be used.
The keyboard controller 40 is equipped with a key top position calculating table 40a, a force curve table 40b, and a film actuator characteristic table 40c. The key top position calculating table 40a is a table that defines the relationship between the detected voltage of the film sensor 32 and the position (or height) of the key top 24. The force curve table 40b is a table that defines the relationship between the position of the key top 24 and the repulsive force generated by the film actuator 31. The film actuator characteristic table 40c is a table that defines the relationship between the repulsive force generated by the film actuator 31 and the drive voltage to be applied to the film actuator 31. These tables are calculated by experiment, simulation or the like.
The driver 41 amplifies the voltage outputted from the keyboard controller 40 and applies the same to the film actuator 31. The amplifier 42 amplifies the detected voltage of the film sensor 32 and outputs the same to the keyboard controller 40.
In
Incidentally, a plurality of force curves (e.g., a force curve small in repulsive force, a force curve large in repulsive force, etc.) may be prepared and configured to be selectable according to the preference of the user.
The keyboard controller 40 calculates a repulsive force of the film actuator 31 corresponding to the calculated position of the key top 24 by referring to the force curve table 40b (Step S3). Subsequently, the keyboard controller 40 calculates a voltage to be applied to the film actuator 31 corresponding to the calculated repulsive force of the film actuator 31 by referring to the film actuator characteristic table 40c (Step S4). Afterwards, the keyboard controller 40 applies the calculated voltage to the film actuator via the driver 41 (Step S5). Thus, the repulsive force corresponding to the position of the key top 24 occurs in the film actuator 31.
Incidentally, although the position of the key top 24, the repulsive force of the film actuator 31 and the voltage applied to the film actuator 31 are calculated using the tables here, they may be calculated using operational expressions. Further, although the voltage for generating the repulsive force of the film actuator 31 corresponding to the position of the key top 24 is calculated using the two two-dimensional tables of the force curve table 40b and the film actuator characteristic table 40c, it may be calculated using a three-dimensional table that defines the relationship among the position of the key top 24, the repulsive force of the film actuator 31 and the voltage applied to the film actuator 31.
A schematic configuration example of the keyboard device 16 according to the present embodiment will next be described.
In
A guide mechanism (pantograph) 51 guides the up/down movement of the key top 24 accompanied with its depression operation. In other words, the guide mechanism 51 guides the depression and return movements of the key top 24. The guide mechanism 51 has a first link member and a second link member. The first link member and the second link member are arranged so as to intersect with each other. The first link member and the second link member are coupled to each other through a shaft 51a in the central part of an intersecting portion and rotated about the shaft 51a. The first link member has one end pivotally supported by an engaging part 34a of the base plate 34 and the other end brought into abutment against the back surface of the key top 24. The second link member has one end pivotally supported by an engaging part 34b of the base plate 34 and the other end brought into abutment against the back surface of the key top 24.
The film actuator 31 is laminated with the film sensor 32 of the same shape as that. The film actuator 31 is an elastic member that generates a repulsive force corresponding to the position of the key top 24. The film actuator 31 has a portion arranged between the base plate 34 and the key top 24 and acting on the key top 24, which penetrates the inner periphery of the guide mechanism 51. The film actuator 31 is brought into contact with the lower surface of the key top 24, and both ends of the portion acting on the key top 24 are fixed to a receiving part 34c of the base plate 34.
The base plate 34 is made of a member having rigidity endurable to the key touch of the user, e.g., a metal and is formed approximately like a plate. The engaging parts 34a and 34b and the receiving part 34c are formed on the base plate 34.
Since the film actuator 31 is not stretched in the state in which no voltage is applied to the film actuator 31 as illustrated in
Incidentally, when the keyboard device 16 becomes active (e.g., where the PC main body is reset from a sleep state when the power supply thereof is ON, etc.), the keyboard controller 40 applies the initial applied voltage to the film actuator 31. When the keyboard device 16 becomes inactive (where a tablet configuration, i.e., configuration in which the keyboard device 16 of the main body side chassis 14 is exposed, is adapted in such a configuration that the display side chassis 12 is rotatable 360° relative to the main body side chassis 14 where the PC main body is in the sleep state when the power supply thereof is OFF, etc.), the keyboard controller 40 may turn OFF the voltage to be applied to the film actuator 31.
According to the present embodiment as described above, the keyboard device is equipped with the base plate 34, the key top 24 vertically movably arranged on the upper surface side of the base plate 34, the film actuator 31 arranged between the base plate 34 and the key top 24 and bent according to the applied voltage, the film sensor 32 arranged between the base plate 34 and the key top 24 and for detecting the position of the key top 24, and the keyboard controller 40 that applies the voltage to the film actuator 31 and generates the repulsive force according to the position of the key top 24 detected by the position sensor. Therefore, with an inexpensive and simple configuration, it is possible to obtain a repulsive force suitable for the user where the key top is depressed, while thinning the keyboard device. Additionally, the keyboard device can be made thinner as compared with the configuration where the rubber dome is used. Further, it is possible to obtain a repulsive force more suitable when the key top is depressed than the case of using vibrations generated by haptic feedback, thereby making it possible to improve usability. Further, the keyboard device can be provided with an inexpensive and simple configuration as compared with the structure of generating a repulsive force by an electromagnetic coil mechanism.
Incidentally, in the above embodiment, the mechanism of generating the repulsive force by the film actuator 31 is applied to the keyboard device 16, but the present invention is not limited by or to this. The present invention can be applied even to a push button device mounted in an electronic apparatus or the like. In this case, the push button device can include as a basic configuration, a configuration equipped with a base, an operating member vertically movably arranged on the upper surface side of the base, a film actuator disposed between the base and the operating member and bent according to a voltage to be applied, a position sensor disposed between the base and the operating member and for detecting the position of the operating member, and control means that applies a voltage to the film actuator to generate a repulsive force corresponding to the position of the operating member detected by the position sensor.
As has been described, the present disclosure provides an improved thin keyboard design.
While the disclosure has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure.
Number | Date | Country | Kind |
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2014-055607 | Mar 2014 | JP | national |