Patent Application
20080180390
The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2006-319586, filed Nov. 28, 2006, and which is hereby incorporated by reference herein in its entirety.
The present invention relates to a non-contact input device that shows a prescribed display through a translucent case in accordance with an operation position that approaches a front surface of the translucent case, and more particularly relates to a non-contact input device that uses an electrostatic capacitance detection method to detect the operation position that approaches the translucent case.
In recent years, there has been a demand to reduce the size of portable equipment, such as portable telephones, which has limited the input operation area that is provided to the front surface of the case for the purpose of inputting operation data; in turn, input operations that require pressing within such a small input operation area have become difficult to perform. Furthermore, to avoid complicating the small front surface of the case, there is a demand to show the prescribed display thereon only during the performance of an input operation—without displaying a switch input unit beforehand.
Accordingly, to solve the aforementioned problems, a non-contact input device has been proposed as described in Japanese Published Unexamined Patent Application No. 2003-178657, which is hereby incorporated by reference herein in its entirety. The device described in the '657 Application comprises a non-contact detecting means that detects, for example, an input operation and an input operation position only when an operating body is brought close to the case; in this non-contact input device, a detection part of the non-contact detecting means is transparent and the prescribed display is shown through the case only during the detection of the input operation.
The light reflecting sheet 103a is notched at the mounting positions of the LEDs 101; accordingly, the LEDs 101, which are mounted to the circuit board 102, are disposed so that they oppose one side surface of the light guiding plate 103. In addition, the transparent electrode 105 is connected to an electrostatic capacitance detection circuit (not shown), which monitors changes in the electrostatic capacitance between the transparent electrode 105 and its surroundings, via a lead-out pattern 105a.
With the non-contact input device 100 configured in this manner, during standby when an input operation is not being performed on the non-contact input device 100, i.e., when a finger (the operating body) is not proximate to the transparent electrode 105, there is no grounded electrode in the surroundings of the transparent electrode 105, and therefore the value of the electrostatic capacitance measured by the electrostatic capacitance detection circuit, which is connected to the transparent electrode 105, is extremely low. In this state, the LEDs 101 do not emit light and the display 106a that is printed on the display panel 106 is inconspicuous.
An input operation is performed on the non-contact input device 100 by bringing a finger close to the interior of the support frame 107. The finger is regarded as an electrode that is connected to a ground potential source via the human body, and therefore electrostatic capacitance increases as the finger approaches the transparent electrode 105; if the electrostatic capacitance detected by the electrostatic capacitance detection circuit exceeds a prescribed value, then operation data that indicate the input operation performed on the non-contact input device 100 are output to a processing device, which is on the equipment side (not shown), and the LEDs 101 are controlled so that they emit light.
The light that is emitted by the LEDs 101 is diffused outwardly (upwardly in the figure) from the light guiding plate 103 by the diffusing sheet 103b, passes through the transparent holding plate 104 and the transparent electrode 105, and irradiates the display 106a, which is printed on the display panel 106, from its rear surface. As a result, the display 106a stands out brightly, and consequently an operator can recognize—without touching the direct non-contact input device 100—the details executed as a result of the input operation and the fact that the input operation was detected.
However, because the non-contact input device 100 detects an input operation based on a change in the electrostatic capacitance of a single transparent electrode 105, it can only detect whether an input operation is being performed; consequently, it cannot detect the input operation position or, based on a change thereof, the input operation direction, and it also cannot be adapted to an input device that outputs operation data that differ by the type of input operation performed.
In addition, because the non-contact input device 100 only detects whether an input operation is being performed, the LEDs 101, which are self luminous devices, can only illuminate the fixed display 106a, which makes the non-contact input device 100 a simplistic display as it cannot show a display that varies in accordance with the type of input operation performed.
Generally, with an electrostatic capacitance detection method that detects different input operation positions non-contactually, a plurality of electrostatic capacitance detection electrodes is disposed on a board and an input operation position is detected based on changes in the electrostatic capacitances of the electrodes; however, if a plurality of electrodes is disposed on the board, the lead-out pattern that leads out from each electrode to the electrostatic capacitance detection circuit leads out to the rear surface side of the board via a through hole so that the electrode does not approach other electrodes or the operating body and thereby generate electrostatic capacitance that would cause an error. However, the board in which the through holes are formed cannot be made transparent and the transparent electrostatic capacitance detecting means that comprises the plurality of electrodes cannot be disposed on the upper side (outer side) of the light source, which comprises self luminous devices; therefore, although there is a demand to show a display on the front surface of the case that varies in accordance with the input operation position, a non-contact input device that achieves this has not been obtained.
Furthermore, with the abovementioned conventional non-contact input device 100, the input device is indicated by the support frame 107, which is disposed on the front surface of the equipment, and a finger or the like is brought close to this support frame 107, which serves as the target of the input operation; however, with a piece of portable equipment that has been reduced in size, such as a portable telephone, it is desirable to make the small front surface of case using a simpler design, and therefore a functional display of a switch input unit degrades the external appearance of the case.
The present invention considers such problems of the conventional art, and it is an object of the present invention to provide a non-contact input device that, only in a case wherein an input operation is performed by bringing an operating body close to a case without the usual display of a switch input unit on a front surface of the case, displays a character or a graphic through the case in accordance with that input operation position.
To achieve the abovementioned object, a non-contact input device according to a first aspect of the invention comprises: a plurality of self luminous devices that is dispersed and mounted on a printed wiring board; a translucent insulating case that covers a front surface side of the printed wiring board whereon the plurality of self luminous devices is mounted; a display control circuit that displays a prescribed character or graphic by individually controlling the flashing of the plurality of self luminous devices; a plurality of transparent electrostatic capacitance detection electrodes that is formed on a rear surface of the translucent insulating case or on one surface of a transparent insulating sheet that is provided and disposed along the rear surface of the translucent insulating case; and an electrostatic capacitance position detecting means that detects an operation position of an operating body based on changes in the electrostatic capacitance between one or two or more of the electrostatic capacitance detection electrodes and the operating body that approaches the front surface of the translucent insulating case; wherein, the display control circuit displays a character or a graphic through the translucent insulating case that differs in accordance with the operation position of the operating body or changes in the operation position of the operating body detected by the electrostatic capacitance position detecting means.
Because the insulating case is translucent, the interior of the case is not externally visible when the display control circuit controls the self luminous devices so that none of them emits light. In this case, the front surface of the insulating case has a simple design wherein the switch input unit is not displayed.
Because a plurality of the electrostatic capacitance detection electrodes is formed on one surface along the rear surface of the insulating case, when an operating body is brought close to the insulating case, the electrostatic capacitance of the electrostatic capacitance detection electrode that is closest to the operating body takes on the largest value, and thereby the operation position can be detected based on the electrostatic capacitance detection electrode that exceeds a prescribed value earliest or on the relative values of the electrostatic capacitances of the electrostatic capacitance detection electrodes. Because the plurality of the electrostatic capacitance detection electrodes is disposed on one surface without the use of an insulating board wherein through holes are formed, a character or a graphic that is displayed by the flashing of multiple self luminous devices is visible from outside of the translucent insulating case.
According to a second aspect of the invention, lead-out patterns, which lead out from the electrostatic capacitance detection electrodes to the electrostatic capacitance position detecting means, on the rear surface of the translucent insulating case or one surface of the transparent insulating sheet are narrowly formed so that the electrostatic capacitance between each lead-out pattern and the operating body decreases to a level at which that electrostatic capacitance can be ignored during the detection of the operation position of the operating body.
If the operating body approaches the front surface of the case, then the electrostatic capacitance between the operating body and the lead-out pattern, which is formed from a conducting material, increases; however, because the lead-out pattern is formed narrowly, that electrostatic capacitance is of an amount that can essentially be ignored when compared with the electrostatic capacitance between the electrostatic capacitance detection electrodes and the operating body, and therefore does not affect the detection of the operation position.
According to a third aspect of the invention, the plurality of electrostatic capacitance detection electrodes is distributed and formed on the rear surface of the translucent insulating case or one surface of the transparent insulating sheet so that no electrostatic capacitance detection electrode is surrounded by other electrostatic capacitance detection electrodes. Therefore it is possible to wire the lead-out patterns, which are connected to the electrostatic capacitance position detecting means, on the same surface so that each lead-out pattern does not approach other electrostatic capacitance detection electrodes.
In the usual state wherein an input operation is not performed, the display that indicates the switch input unit is not displayed on the front surface of the case, and therefore the external appearance of the front surface of the case does not become complicated, and it is possible to make a device that comprises the non-contact input device with a simple design.
In addition, because different characters and graphics are displayed through the case in accordance with the position at which the operating body approaches the case, it is possible to convey the fact that the input operation has been detected, as well as the details of that detected input operation, to the operator who has performed the input operation non-contactually.
Because an input operation direction can be detected based on changes in the detected operation position, it is also possible to display different characters and graphics through the case in accordance with the input operation direction. Accordingly, even if the number of electrostatic capacitance detection electrodes formed on one surface is limited, an input operation can output a great variety of operation data.
By forming the electrostatic capacitance detection electrodes on the same surface, without using a board wherein through holes are formed, it is possible to detect the operation position of the operating body with greater accuracy.
By providing no electrostatic capacitance detection electrode that is surrounded by other electrostatic capacitance detection electrodes, it is possible to wire each lead-out pattern, which leads out from one of the electrostatic capacitance detection electrodes to the electrostatic capacitance position detecting means, so that it does not approach other electrostatic capacitance detection electrodes. Accordingly, because the electrostatic capacitance effect of each of the lead-out patterns is small and the lead-out patterns are not affected by capacitance coupling with other electrostatic capacitance detection electrodes, it is possible to detect the operation position more accurately.
The invention will become more readily apparent from the Detailed Description of the Invention, which proceeds with reference to the drawings, in which:
In the figures, elements that are repeatedly illustrated are consistently identified by a single reference numeral.
The following table provides a key to the reference numerals and elements depicted in the drawings.
A non-contact input device 1 according to one embodiment of the present invention will now be explained, referencing
A flexible wiring board 5, which is formed from a transparent synthetic resin material, is attached along a rear surface of the insulating case 2. As shown in
A flexible tail 5a, one end of which is connected to an FPC connector 8, is formed integrally with the flexible wiring board 5, and lead-out patterns 6, each of which is made of transparent silver patterns that lead out from the electrostatic capacitance detection electrodes 4, are printed along the longitudinal direction of the flexible tail 5a. As illustrated in
The printed wiring board 7 of
A driver 11, which is shown in
The controller 9, which comprises the electrostatic capacitance position detection circuit 9A and the display control circuit 9B, is configured by a single chip microcontroller and is mounted to the printed wiring board 7 on the rear surface side. The electrostatic capacitance position detection circuit 9A outputs detection values that are in accordance with the electrostatic capacitance between each of the electrostatic capacitance detection electrodes 4 and ground, and determines that an input operation has been performed when the maximum value of each detection value exceeds a prescribed input determination value. Here, the input determination value may be set to a value such that it is determined that an input operation has been performed when a finger approaches a position that is approximately 10 cm from the front surface of the insulating case 2.
If it is determined that an input operation has been performed, the input operation position thereof is detected subsequently. Here, the front surface area of all of the electrostatic capacitance detection electrodes 4 are identical, and it is therefore assumed that the electrostatic capacitance detection electrode 4 that has the maximum detection value is the one that is most proximate to the operating finger, and the array position of that electrostatic capacitance detection electrode 4 is detected as the input operation position. This input operation position may optionally be derived more accurately from the centroid of the detection values of the electrostatic capacitance detection electrodes 4. In addition, after it is determined that an input operation has been performed, the input operation position is detected at fixed intervals, and an input operation direction may be detected based on detecting changes in the input operation position.
The controller 9 outputs prescribed operation data that correspond to the detected input operation position or the input operation direction to a processing device (PC) 13, which executes a prescribed process based on the operation data, via an interface 12, and outputs a display control signal that corresponds to the detected input operation position or the input operation direction from the display control circuit 9B to the driver 11 for operating the LEDs 3.
The operation of the non-contact input device 1 configured in this manner will now be explained. During a standby state—when the finger is not brought close to the insulating case 2—a conductor that is at ground potential does not approach the electrostatic capacitance detection electrodes 4, and therefore the electrostatic capacitance detected from each of the electrostatic capacitance detection electrodes 4 is extremely low and none of the detection values reaches the input determination value. During this time, the non-contact input device 1 determines that the state is the standby state, wherein an input operation is not performed, and the display control circuit 9B performs control so as to turn off all of the light emitting diodes 3. Accordingly, light is not emitted to the translucent insulating case 2 from the interior, only the front surface of the case 2 is visible, and the structure of the input device 1 therein does not appear on the front surface side.
In order to perform an input operation on the non-contact input device 1, an operator brings his or her finger close to the front surface of the insulating case 2; as the finger approaches, the electrostatic capacitance to ground through the body of the operator gradually increases; when the finger approaches within 10 cm of the front surface of the insulating case 2, the detection value that corresponds to the electrostatic capacitance of the electrostatic capacitance detection electrode 4 that is closest to the finger exceeds the input determination value, whereupon the electrostatic capacitance position detection circuit 9A determines that an input operation has been performed. Because the electrostatic capacitance detection electrode 4 for which the maximum detection value is detected at this time is the one that is closest to the approaching finger, and therefore the array position of that electrostatic capacitance detection electrode 4 is detected as the input operation position.
If the display control circuit 9B of the controller 9 detects the input operation and the input operation position, then it outputs a display control signal that performs control so as to turn on the 16 light emitting diodes 3 disposed below the electrostatic capacitance detection electrode 4 at the input operation position to the driver 11, and these light emitting diodes 3 emit light. The light emitted from the 16 light emitting diodes 3 passes through the transparent flexible wiring board 5 and that transparent electrostatic capacitance detection electrode 4, and irradiates the rear surface of the translucent insulating case 2; thereby, a square graphic below the operating finger is displayed through the insulating case 2. Accordingly, the operator can know—without touching the insulating case 2 of the portable telephone—that the input operation and the input operation position have been detected by the non-contact input device 1.
In the controller 9, while the electrostatic capacitance position detection circuit 9A is detecting whether an input operation has been performed, i.e., as long as the maximum value of each detection value is less than the input determination value, it detects the input operation position periodically with the same method, and if the input operation position changes over time, then an operation direction of the input operation is also detected.
Here, for example, if the array positions of the three electrostatic capacitance detection electrodes 4 in any row shown in
According to the present embodiment, portable equipment, such as portable telephones for which there is particular demand for size reduction, can be made with a simple design so that the external appearance looks as if an input device is not provided; furthermore, such portable equipment is capable of non-contactually inputting a variety of operation data with a small input operation area.
In the present embodiment of the present invention, the lead-out patterns 6 that lead out from the electrostatic capacitance detection electrodes 4 are disposed along the rear surface of the insulating case 2, which is the surface that opposes the approaching operating body. In particular as illustrated as
Furthermore, in order to reduce further the detection errors caused by the electrostatic capacitance of the lead-out pattern 6A, the electrostatic capacitance detection electrode 4A that is disposed at the center of the 3 row by 3 column matrix may be omitted. In the case of electrostatic capacitance detection electrodes 4 wherein the centrally disposed electrostatic capacitance detection electrode 4A is omitted, there is no electrostatic capacitance detection electrode 4 that is disposed so that it is surrounded by other electrostatic capacitance detection electrodes 4, and therefore it is possible for the lead-out patterns 6 to lead out to the electrostatic capacitance position detection circuit 9A from the perimeters of the electrostatic capacitance detection electrodes 4 without having to lead out through a gap between other electrostatic capacitance detection electrodes 4.
The electrostatic capacitance detection electrodes 21 are formed by partitioning a circular electrode into eight parts at equiangular intervals so that they form equal fan shapes, and all eight electrostatic capacitance detection electrodes 21 together form a circle; therefore, lead-out patterns 23, each of which leads out from the arcuate perimetric edge of one of the electrostatic capacitance detection electrodes 21, can lead out from a flexible tail 22a such that each lead-out pattern 23 does not approach other electrostatic capacitance detection electrodes 21. Accordingly, even though a plurality of the electrostatic capacitance detection electrodes 21 is formed on one surface of the transparent flexible wiring board 22 wherein no through hole is provided, the electrostatic capacitance between each of the lead-out patterns 23 and other electrostatic capacitance detection electrodes 21 is extremely low, which makes it possible to detect the operation position accurately.
In addition, disposing the identically shaped electrostatic capacitance detection electrodes 21 at equiangular intervals in this manner makes it possible to detect an operation position on the circumference, as well as to detect a rotational operation direction and a rotational operation speed more accurately when the finger performs a rotational operation.
Furthermore, the electrostatic capacitance detection electrodes 4 and the lead-out patterns 6 that lead out therefrom, as well as the electrostatic capacitance detection electrodes 21 and the lead-out patterns 23 that lead out therefrom, which were all discussed above, may be formed directly on the rear surface or within the walls of the translucent insulating case 2.
In addition, the embodiments discussed above explained a case wherein the light emitting source that shows the prescribed display comprises the light emitting diodes 3; however, instead of the light emitting diodes 3, the light emitting source may be some other light emitting device, such as an EL (electroluminescence) light emitting device, as long as it is a self luminous device.
It is within the scope of the present invention to include all foreseeable equivalents to the elements and structures as described with reference to
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-319586 | Nov 2006 | JP | national |
