Summary of the invention
The object of the present invention is to provide a kind of control board transducer, be intended to solve that the capacitive sensing sensitivity that exists in the prior art is not high, the big problem of cladding thickness control difficulty;
Another object of the present invention is to provide a kind of display device.
The present invention realizes like this, a kind of control board transducer, described transducer comprises a capacitive induction button, and be connected with described capacitive induction button, detect the capacitance detector of its capacitance variations, described capacitive induction button comprises two copper sheets, a copper sheet ground connection wherein, form an electric capacity between described two copper sheets, be coated with insulating barrier on described two copper sheets, described insulating barrier is provided with an induction antenna, form an electric capacity respectively between described induction antenna and two copper sheets, described capacitance detector comprises a capacitance switch, one charge power supply, one comparator, one reset switch, one pulse-width modulator and a timer, described charge power supply, comparator and reset switch are formed a relaxation oscillator, and described relaxation oscillator continues to discharge and recharge to described control board transducer.
Described induction antenna is a conductive sponge.
A kind of display device, described equipment comprises a control board transducer, described control board transducer comprises a capacitive induction button, and be connected with described capacitive induction button, detect the capacitance detector of its capacitance variations, described capacitive induction button comprises two copper sheets, a copper sheet ground connection wherein, form an electric capacity between described two copper sheets, be coated with insulating barrier on described two copper sheets, described insulating barrier is provided with an induction antenna, form an electric capacity respectively between described induction antenna and two copper sheets, described capacitance detector comprises a capacitance switch, one charge power supply, one comparator, one reset switch, one pulse-width modulator and a timer, described charge power supply, comparator and reset switch are formed a relaxation oscillator, and described relaxation oscillator continues to discharge and recharge to the electrode of described control board transducer.
Described induction antenna is a conductive sponge.
Described display device is display or television set.
In the present invention, by in the control board transducer, increasing by an induction antenna, strengthened the sensitivity of control board transducer, thereby reduced the distance of reaction between capacitive induction button and the conductor.Utilize control board transducer provided by the invention to realize the no touch control of function button on various tv products and the display product and switch key simultaneously.
Embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
In the present invention, by on the copper sheet of the capacitive induction button that constitutes the control board transducer, increasing by an insulating barrier, on insulating barrier, increase by an induction antenna, increased the sensitivity of capacitive induction button, thereby reduce the influence of cladding thickness the capacitive induction button.In the present invention simultaneously, utilize the control board transducer to realize the function button on various tv products and the display product and the no touch control of switch key.
Control board transducer of the present invention comprises at least one capacitive induction button and the capacitance detector that is connected with this capacitive induction button.
Fig. 1 shows the structure of capacitive induction button, and details are as follows:
The capacitive induction button comprises two copper sheets 1, a copper sheet ground connection wherein, an electric capacity that forms between two copper sheets 1.Suppose that the total capacitance value between copper sheet 1 and the ground is C
PWhen the capacitive induction button is not pressed, form a parasitic capacitance C between copper sheet 1 and the ground
Y, at this moment, C
P=C
YWhen a conducting element 3 (this conducting element can be finger, human body etc.) when the capacitive induction button, according to the sensing principle of capacitive induction technology, will produce an additional capacitor C
X, make the total capacitance C between copper sheet and the ground
PValue increase, this moment C
P=C
Y+ C
XPlating one deck drop oil is as insulating barrier on copper sheet 1, insulating barrier is provided with the induction antenna 5 of sensing effect together, this induction antenna can be conductive sponge, it has very strong conductivity, can strengthen the sensitivity of capacitive induction button, reduce the distance of reaction between capacitive induction button and the conductor.On induction antenna 5, cover a glassy layer 7, with protection capacitive induction button.Because the sensitivity of capacitive induction button has increased, the thickness of this glassy layer is controlled relatively easily.Detect the capacitance variations of capacitive induction button by capacitance detector and can judge whether the capacitive induction button is pressed.
Fig. 2 shows the composition of capacitance detector, and details are as follows:
This capacitance detector is used for detecting the capacitance variations of capacitive induction button, presses to have judged whether button.Capacitance detector comprises a capacitance switch, a charge power supply, a comparator, a reset switch, a pulse-width modulator (PWM) and a timer.Wherein capacitance switch is connected with above-mentioned capacitive induction button, continues to discharge and recharge by the relaxation oscillator be made up of comparator, charge power supply and the reset switch electrode capacitance to the capacitive induction button.Simultaneously, an electric capacity charge threshold V is set in comparator
TH, the output of comparator is sent to the clock input circuit of PWM, and the output of PWM is connected to the pin of catching of timer, and the output of PWM all will be enabled a timer.When charging capacitor reaches electric capacity charge threshold V
THThe time, calculate the count value (n) of timer.Wherein the count value of timer (n) is for reaching electric capacity charge threshold V when charge and discharge capacitance
THThe time, the capacitor charge and discharge number of times.
The count value of timer (n) can be associated with a specific thresholding.When the count value of timer during, think that the capacitive induction button is pressed, otherwise think and be not pressed less than this specific threshold value.
Determining of this specified threshold is relevant with the induction sensitivity of residing environment of display and capacitive induction button.As: suppose not to be pressed when the capacitive induction button, charging/discharging voltage reaches V
THThe time, the count value of timer is n1; When the capacitive induction button has conductor approaching, charging/discharging voltage reaches V
THThe time, the count value of timer is n2.On the principle, as long as the value of n2 can think then that less than the value of n1 the capacitive induction button is pressed at this moment.But the capacitive induction button is subject to environmental impact of living in, when the increase of the temperature of the residing environment of display or humidity, may increase the capacitance of capacitive induction button, make when not having conductor close, capacitance bridge charge conversion detection method also judges have button to press, and causes operate miss.Therefore, in the method that the capacitance bridge charge conversion detects,, avoid the misjudgment that causes because of capacitance variations that environmental change causes by setting a specified threshold.Have only when n value during, think that just switch is pressed less than this specified threshold.
When the sensitivity of capacitive induction button improved, the setting of this specified threshold also can correspondingly increase, thereby can increase the distance of reaction between capacitive induction button and the conductor.Its concrete big I is according to cladding thickness, the sensitivity of capacitive induction button, by repeatedly test is definite.Because when the distance between conductor and the capacitive induction button was big more, the sensitivity of inductive switch was low more, have only so when setting smaller threshold value, could guarantee the correct induction of induction type capacitance switch.
In the present invention, by on the electrode of capacitive induction button, increasing by a conductive sponge, this conductive sponge can increase the sensitivity of capacitive induction button, thereby can determine relatively large specified threshold, has increased the distance of reaction between conductor and the capacitive induction button.
Fig. 3 shows the hardware circuit of the application of control board transducer of the present invention on display.
Because the PSoC SOC (system on a chip) comprises 8 digital modules and 12 analog modules.The user can define the needed function of user by these modules are configured.As: digital module can be configured to functional modules such as timer, counter, serial communication port (UARTS), CRC generator, PWM; Analog module can be configured to functional modules such as analog to digital converter, digital to analog converter, programmable gain amplifier, programmable filter, differential comparator.Digital module and analog module also can constitute modulator-demodulator, complicated motor controller, the treatment circuit of sensor signal etc.
Be configured by internal hardware in the present invention, be configured to form the capacitance detector of control board transducer PSoC chip CY8C21534.The state of the electrode of the CY8C21534 chip cycle detection capacitive induction button that is configured has judged whether that button presses.The CY8C21534 chip is connected with burned device by the burned socket of software, and the internal hardware of CY8C21534 IC chip is configured.Its concrete configuration is as follows: comparator takies an analog module, and its in-phase input end multiway analog switch is connected with the capacitive induction button by the I/O interface, and its inverting input connects internal reference voltage as electric capacity charge threshold V
TH, be used for comparing with input terminal voltage.The output of comparator is sent to the clock input circuit of pulse-width modulator (PWM).This PWM pulse width modulation module takies 1 digital module, and its clock input is connected with the output of comparator, and the output of PWM is connected to the pin of catching of timer.1 16 bit timing device takies 2 digital modules, timing is carried out in the pulse of PWM output, and calculated the count value (n) of timer.
As a specific embodiment of the present invention, display is provided with 5 capacitive induction buttons, be respectively: Menu capacitive induction button, Auto capacitive induction button, On/Of capacitive induction button, "-" capacitive induction button and "+" capacitive induction button are used for adjusting display.Each capacitive induction button is connected with the corresponding pin of CY8C21534 chip respectively by lead.
PSoC chip CY8C21534 detects the capacitive induction button and is pressed through configuration, is connected with the control unit (LCD-MCU) of display by the gang socket of display control unit, and testing result is sent to LCD-MCU.In running order when display, control the operation that display responds corresponding capacitance formula induced key by LCD-MCU according to the testing result of CY8C21534 chip, and send instruction, the prompting of buzzer song to buzzer.The CY8C21534 chip provides operating voltage for corresponding induction indicator light simultaneously, shows with the corresponding LED lamp of the capacitive induction button that is pressed.
As mentioned above, in the present invention, by on the capacitive induction button, increasing by an induction antenna, strengthened the sensitivity of capacitive induction button, and by PSoC chip CY8C21534 being configured to the capacitance detector of capacitance variations that is used to detect the capacitive induction button of control board transducer, make the control board transducer on display product, be applied, and this control board transducer the application principle on the tv product on similar, do not repeat them here.
Fig. 4 shows the module of the specific implementation of the application of control board transducer of the present invention on display and forms, and details are as follows:
When display in running order, be that display is not when being closed, working power module 31 provides operating voltage for capacitance detector module 32 and LCD-MCU module 33 simultaneously, capacitance detector herein can be the CY8C21534 chip, so that capacitance detector module and LCD-MCU module can mutual communication, realize of the operation of capacitive induction button to display.The on and off of the power supply indicator in the voltage-controlled source indicator light control module 36 that provides according to working power module 31 of LCD-MCU module 33 simultaneously.When the close induction of conductor control module 34, according to the capacitive induction principle, application-specific integrated circuit module 32 detects the existence of conductor, and application-specific integrated circuit module 32 is sent instruction to induction indicator light control module 35, simultaneously for it provides operating voltage, make that to respond to indicator light accordingly bright with the capacitive induction button.Simultaneously capacitance detector module 32 is sent instruction to LCD-MCU module 33, the voltage of LCD-MCU module 33 is reduced, and LCD-MCU module 33 detects the change in voltage of himself, judges that switch is pressed, send instruction to buzzer control module 37, the prompting of buzzer song.
The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.