The invention relates to piezoelectric input sensors and to devices in which such piezoelectric sensors are used.
European patent application of the present applicant published under publication number EP 2 770 637 A1 (the contents of which are incorporated herein by reference)—hereinafter the '637 publication—describes a piezoelectric switch circuit having at least one piezoelectric sensor element. FIG. 10 thereof has been redrawn as
The piezoelectric sensor elements of the piezoelectric switch circuit of the '637 publication and also that shown in
A piezoelectric switch circuit configured to detect a signal resulting from bending of at least one piezoelectric sensor element being part of the circuit and also to produce a haptic signal, like the piezoelectric switch circuit disclosed in the '638 publication, where the haptic signal is produced by a boost converter (cf.
It is understood that since each piezoelectric sensor element requires one microcontroller channel for reading sensor inputs and each piezoelectric sensor element that is used to produce a haptic signal requires a further microcontroller channel for switching the haptic signal, the number of channels required at the microcontroller will be rapidly increased with an increasing number of piezoelectric sensor elements used to produce a haptic signal. This is considered as a disadvantage.
It is an objective of the invention to simplify circuit design in the context of producing haptic signaling in a piezoelectric sensor comprising a plurality of piezoelectric sensors, of which at least two are useable for producing haptic signaling.
This objective can be fulfilled with the piezoelectric sensor according to claim 1, with the device comprising a piezoelectric sensor according to claim 6.
The piezoelectric sensor comprises a microcontroller, and a plurality of piezoelectric sensor elements of which at least two are a) useable for producing a haptic signal by a voltage generated by a boost converter connected to each piezoelectric sensor element via a respective switch, and b) connected to a piezo channel of the microcontroller.
The piezoelectric sensor further comprises a multiplexer for individually controlling each of the switches for which a signal is present at a digital selection line connected to the respective piezo channel, if a signal from an increase voltage pin is present.
The microcontroller is configured:
The piezoelectric sensor enables a simplified circuit design with respect to the microcontroller, in which a piezo channel can be used both to collect sensor input from a piezoelectric sensor element and to set a signal to cause the multiplexer to effect the closing of the switch to generate haptic feedback at the same piezoelectric sensor.
If the piezo channel is connected to the piezoelectric sensor element for reading a signal resulting from bending of the piezoelectric sensor element, the same piezo channel can be shared for collecting the signal resulting from bending of the piezoelectric sensor and also for setting the signal to cause the multiplexer to effect the closing of the switch to generate haptic feedback at the same piezoelectric sensor.
The boost converter may be configured to produce the voltage if a signal generated by the microcontroller is present in the increase voltage pin and/or in the enable signal pin of the microcontroller. Alternatively, the boost converter may be configured to produce the voltage if a signal generated by a multiplexer function in the multiplexer is present. The signal can be derived from signal from the increase voltage pin of the microcontroller, in which case the signal at the enable signal pin is not necessarily needed at the microcontroller output.
Preferably, the microcontroller is configured to use the piezo channel in a time-interleaved manner for receiving sensor input from a piezoelectric sensor element and for giving output for a digital selection line to the multiplexer.
The device comprises a surface at least one a piezoelectric sensor according to the first aspect of the invention attached to the surface from below such that the at least one piezoelectric sensor is useable as a touch sensor through the surface and for producing haptic feedback through the surface.
In the following, the invention will be explained in more detail with reference to the embodiments shown in
Same reference numerals refer to same or similar structural elements in all FIG.
The exemplary embodiments of piezoelectric device 2′ according to the present invention will be explained in detail with additions and amendments to piezoelectric device 2 disclosed in the '638 publication. For the sake of conciseness, the reader is referred to the '638 publication as regards the detailed explanation of any components and the respective circuitry not explicitly described in the following.
Furthermore, for the more detailed structure of device 1 and the arrangement of piezoelectric device 2′ in the device 1, the reader is referred to
As can be more easily understood from
The fewer microcontroller 26 channels are needed for controlling switching of a haptic signal and for detection of signals from piezoelectric sensor elements 20, the more channels are available with the existing microcontroller 26 configurations.
The principle of operating the boost converter 1101 to produce a haptic signal is described in more detail with reference to
Preferably, the HVEN signal is only activated when the DRVP has switching activity and toggles with logic part 81 (cf.
The haptic channel selection is needed only during haptic booster upward drive, since the downward drive by transistor 1107 utilizes the HV switch diodes 1106 inside the haptic output switches 1105 to drain the charge from the PHZ<i> nodes.
The piezoelectric sensor 2′ comprises a microcontroller 26 and a plurality of piezoelectric sensor elements 20, of which at least two are:
The piezoelectric sensor 2′ further comprises a multiplexer 80 for individually controlling each of the switches 1105 for which a signal is present at a digital selection line connected to the respective piezo channel (PZF1; PZF2; PZF3), if signal DRVP from increase voltage pin (53) is present.
The multiplexer 80 can be implemented as an array of individually controllable switches in the switching part 82. The logic part 81, electrically connected to the increase voltage pin 53 of the microcontroller 26, is configured to individually control the switches in the switching part 82 for which there is a signal present in the respective piezo channel (PZF1, PZF2, PZF3) and if the signal DRVP at the increase voltage pin 53 is present. Consequently, the signal in the respective piezo channel (PZF1, PZF2, PZF3) then controls the respective switch 1105.
The microcontroller 26 is configured:
The microcontroller 26 is configured to use the piezo channel (PZF1; PZF2; PZF3) in a time-interleaved manner for receiving sensor input from a piezoelectric sensor element 20 and for giving output for a digital selection line to the multiplexer 80.
Preferably, the piezo channel (PZF1; PZF2; PZF3) is connected to the piezoelectric sensor element 20 for reading a signal resulting from bending of the piezoelectric sensor element 20.
Enable signal pin 54 of microcontroller 26 is connected to boost converter 1101. Boost converter 1101 produces a high voltage when signal HVEN is present in enable signal pin 54 and signal DRVP is present in increase voltage pin 53.
The multiplexer 80 is configured to operate its switching part 82 to trigger its output lines (going to haptic output switch 1105, I; 1105, II; 1105, III, respectively) in response to a signal in a respective input line (coming from PZF1, PZF2, PZF3, respectively) being present, if at the same time the increase voltage (DRVP) signal is present.
In the embodiment shown in
The advantage of the approach illustrated in
In yet another embodiment, an signal DRVP for both boost converter 1101 and multiplexer 80 can be generated with a suitable configuration of microcontroller 26. Signal HVEN is generated in enable signal pin 54 during upward drive. The signal HVEN can in this case be passed to both converter 1101 and multiplexer 80.
In the method of using a piezo channel (PZF1; PZF2; PZF3) of a microcontroller 26, the piezo channel (PZF1; PZF2; PZF3) is used
The many features and advantages of the present invention are apparent from the written description. Further, since numerous modifications and changes will be readily apparent to those skilled in the art, the invention should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.
In particular, the number of piezoelectric sensors 2′ may be different from three. Furthermore, it is not necessary that each piezoelectric sensor 2′ is configured so that a haptic signal can be switched over it.
Number | Date | Country | Kind |
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14192448 | Nov 2014 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/076193 | 11/10/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2016/075131 | 5/19/2016 | WO | A |
Number | Name | Date | Kind |
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7446456 | Maruyama | Nov 2008 | B2 |
20110127880 | Murphy et al. | Jun 2011 | A1 |
20111028250 | Murphy et al. | Jun 2011 | |
20130200871 | Sprentall | Aug 2013 | A1 |
Number | Date | Country |
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102822775 | Dec 2012 | CN |
103683516 | Mar 2014 | CN |
2770638 | Aug 2014 | EP |
2846479 | Apr 2004 | FR |
2011 002926 | Jun 2011 | JP |
2011 048696 | Oct 2011 | JP |
2016 075131 | May 2016 | WO |
Entry |
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Jan. 8, 2019 Notice of Rejection from Japanese Patent Office (original and English translation). |
International Search Report and Written Opinion for PCT Application PCT/EP2015/076193, EPO, dated Feb. 18, 2016. |
Translation of office action from Japanese Patent Office in corresponding Japanese Patent Application 2017-543892 and dated Sep. 11, 2018. |
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Office Action dated Dec. 25, 2019 from National Intellectual Property Administration, P.R. China and Search Report English Translation. |
Number | Date | Country | |
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20170324020 A1 | Nov 2017 | US |