CN201113981Y - Press key detection circuit - Google Patents
Press key detection circuit Download PDFInfo
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- CN201113981Y CN201113981Y CNU2007201216475U CN200720121647U CN201113981Y CN 201113981 Y CN201113981 Y CN 201113981Y CN U2007201216475 U CNU2007201216475 U CN U2007201216475U CN 200720121647 U CN200720121647 U CN 200720121647U CN 201113981 Y CN201113981 Y CN 201113981Y
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Abstract
The utility model discloses a key detection circuit, which comprises at least a key detection unit circuit, wherein, various key detection unit circuits are used for detecting key actions corresponding to the key detection unit circuits; the key detection unit circuit comprises a low-level detection circuit, a low-level output end, a high-level detection circuit, a high-level output end and a detection level input end; the low-level detection circuit is connected between the low-level output end and the detection level input end; the high-level detection circuit is connected to the high-level output end and the detection level input end; one end of a key is alternately connected with the low-level output end or the high-level output end of the corresponding key detection unit circuit while the other end is connected with a detection output end of the key together. The key detection circuit designed by the utility model not only can detect high level but also can detect low level, and can be suitable for different level detection requirements, thereby convenience is brought to software design.
Description
Technical field
The utility model relates to electronic circuit, relates in particular to a kind of key press detecting circuit.
Background technology
Key press detecting circuit is a kind of circuit the most basic in the design of electronic circuits, is applied in the control system of various band buttons.Key press detecting circuit generally comprises low level key press detecting circuit and high level key press detecting circuit, common low level key press detecting circuit as shown in Figure 1, it comprises a plurality of diodes, each diode correspondence is in the detection of a button, negative electrode at each diode is given a low level seriatim, and the end away from diode of button links to each other with detection I/O (input and output) mouthful, button detects the I/O mouth because pull-up resistor remains high level at ordinary times, when button is pressed, button detects the I/O mouth and detects the low level input, i.e. explanation its series diode negative electrode this moment is applied in low level button and is pressed.Detect the key press detecting circuit of high level, its principle is identical with said method.
The defective of key press detecting circuit of the prior art is, no matter be high level key press detecting circuit or low level key press detecting circuit, they all are to detect a kind of level, this requires to detect the design that this part will satisfy hardware circuit fully at button on the software design, and software development has been subjected to certain restriction.
Summary of the invention
Technical problem to be solved in the utility model provides a kind of key press detecting circuit, can eliminate the restriction of key press detecting circuit to software development, improves the adaptability of key press detecting circuit.
In order to solve the problems of the technologies described above, the utility model has adopted following technical scheme:
A kind of key press detecting circuit, comprise at least one button detection cell circuit, each button detection cell circuit is used for detecting actuation of keys corresponding with it, described button detection cell circuit comprises the low level testing circuit, the low level output, high-level detection, high level output and detection level input, described low level testing circuit is connected between described low level output and the described detection level input, described high-level detection is connected described high level output and described detection level input, described button one end is selected a ground and is linked to each other with the low level output or the high level output of corresponding button detection cell circuit, and the other end detects output with button jointly and links to each other.
Described low level testing circuit comprises first diode, and described first diode cathode links to each other with detection level input, and anode links to each other with the low level output.
Described high-level detection comprises switching tube, second diode, resistance, described second diode cathode links to each other with the high level output, and anode extremely links to each other with switching tube the 3rd, described switching tube first utmost point links to each other with detection level input through described resistance, and second utmost point links to each other with a logic high.
Described switching tube is the positive-negative-positive triode, described first base stage very, described second emitter-base bandgap grading very, the described the 3rd collector electrode very.
The key press detecting circuit of the utility model design can detect high level, can detect low level again, only needs a selection key to link to each other with low level output or high level output, just can adapt to different level detection requirements, thereby has brought convenience for software design.
Description of drawings
Fig. 1 is a low level key press detecting circuit structural representation of the prior art;
Fig. 2 is the key press detecting circuit structural representation of the utility model embodiment.
Embodiment
The utility model is described in further detail in conjunction with embodiment for the contrast accompanying drawing below.
As shown in Figure 2, the key press detecting circuit of the preferred embodiment of the utility model comprises at least one button detection cell circuit, 3 button detection cell circuit shown in Fig. 2, obviously, its quantity can be adjusted accordingly according to the number of keys that will detect.Each button detection cell circuit is used to detect the action of pressing of button K corresponding with it, comprise the low level testing circuit, low level output 1, high-level detection, high level output 2 and detection level input 3, the low level testing circuit is connected low level output 1 and detects between the level input 3, high-level detection is connected high level output 2 and detects level input 3, button K one end is selected a ground and is linked to each other with the low level output 1 or the high level output 2 of corresponding button detection cell circuit, and the other end detects output 4 with button jointly and links to each other.
The low level testing circuit comprises the first diode D1, and the first diode D1 negative electrode links to each other with detection level input 3, and anode links to each other with low level output 1.
High-level detection comprises switching tube Q, the second diode D2, resistance R, the second diode D2 negative electrode links to each other with high level output 2, and anode extremely links to each other with switching tube Q the 3rd, switching tube Q first utmost point links to each other with detection level input 3 through resistance R, and second utmost point links to each other with a logic high.In the present embodiment, logic high employing+5V.
Switching tube Q can be a triode, can be metal-oxide-semiconductor also, adopts the positive-negative-positive triode in the present embodiment, and is corresponding, above-mentioned first base stage very, second emitter-base bandgap grading very, the 3rd collector electrode very.
The detection level is a low level, the detection level of each button detection cell circuit adopts input mode one by one, promptly when detecting, the detection level input 3 of each button detection cell circuit is input low level seriatim, concrete operation principle is: when needs high level button detects, button K is linked to each other with high level output 2, detect level input 3 input low levels, the base stage that is switching tube Q is a low level, switching tube Q conducting, when button K pressed, this moment, button detected output 4 output high level, had realized that the high level button detects.And when needs low level button detects, button K is linked to each other with low level output 1, detect level input 3 input low levels, to press at button K, this moment, button detected output 4 output low levels, had realized that the low level button detects.
This compatible type key press detecting circuit only needs according to actual selection employing low level testing circuit or high-level detection just can adapt to different level detection requirements, for software design has been brought convenience.Moreover, owing to adopt the key press detecting circuit of this design to link to each other with the control board that the high level button detects, also can link to each other with the control board that the low level button detects, therefore can save the design cost of PCB (printed circuit board (PCB)), reduce the quantity of PCB model simultaneously, be of value to control and management.
Above content be in conjunction with concrete preferred implementation to further describing that the utility model is done, can not assert that concrete enforcement of the present utility model is confined to these explanations.For the utility model person of an ordinary skill in the technical field, under the prerequisite that does not break away from the utility model design, can also make some simple deduction or replace, all should be considered as belonging to protection range of the present utility model.
Claims (4)
1. key press detecting circuit, comprise at least one button detection cell circuit, each button detection cell circuit is used for detecting button corresponding with it (K) action, it is characterized in that, described button detection cell circuit comprises the low level testing circuit, low level output (1), high-level detection, high level output (2) and detection level input (3), described low level testing circuit is connected between described low level output (1) and the described detection level input (3), described high-level detection is connected described high level output (2) and described detection level input (3), described button (K) end is selected a ground and is linked to each other with the low level output (1) or the high level output (2) of corresponding button detection cell circuit, and the other end detects output (4) with button jointly and links to each other.
2. key press detecting circuit as claimed in claim 1 is characterized in that, described low level testing circuit comprises first diode (D1), and described first diode (D1) negative electrode links to each other with detection level input (3), and anode links to each other with low level output (1).
3. key press detecting circuit as claimed in claim 1, it is characterized in that, described high-level detection comprises switching tube (Q), second diode (D2), resistance (R), described second diode (D2) negative electrode links to each other with high level output (2), anode extremely links to each other with switching tube (Q) the 3rd, and described switching tube (Q) first utmost point links to each other with detection level input (3) through described resistance (R), and second utmost point links to each other with a logic high.
4. key press detecting circuit as claimed in claim 3 is characterized in that, described switching tube (Q) is the positive-negative-positive triode, described first base stage very, described second emitter-base bandgap grading very, the described the 3rd collector electrode very.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201216475U CN201113981Y (en) | 2007-07-19 | 2007-07-19 | Press key detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201216475U CN201113981Y (en) | 2007-07-19 | 2007-07-19 | Press key detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201113981Y true CN201113981Y (en) | 2008-09-10 |
Family
ID=39965729
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007201216475U Expired - Lifetime CN201113981Y (en) | 2007-07-19 | 2007-07-19 | Press key detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201113981Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102111467A (en) * | 2011-03-04 | 2011-06-29 | 惠州Tcl移动通信有限公司 | Mobile phone and key detection device thereof |
| CN102998619A (en) * | 2012-11-28 | 2013-03-27 | 深圳和而泰智能控制股份有限公司 | Method, device and system for testing sensing buttons |
| CN110716115A (en) * | 2018-06-27 | 2020-01-21 | 京东方科技集团股份有限公司 | Ultrasonic signal detection circuit, ultrasonic signal detection method, and display panel |
-
2007
- 2007-07-19 CN CNU2007201216475U patent/CN201113981Y/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102111467A (en) * | 2011-03-04 | 2011-06-29 | 惠州Tcl移动通信有限公司 | Mobile phone and key detection device thereof |
| CN102111467B (en) * | 2011-03-04 | 2014-07-30 | 惠州Tcl移动通信有限公司 | Mobile phone and key detection device thereof |
| CN102998619A (en) * | 2012-11-28 | 2013-03-27 | 深圳和而泰智能控制股份有限公司 | Method, device and system for testing sensing buttons |
| CN102998619B (en) * | 2012-11-28 | 2015-07-15 | 深圳和而泰智能控制股份有限公司 | Method, device and system for testing sensing buttons |
| CN110716115A (en) * | 2018-06-27 | 2020-01-21 | 京东方科技集团股份有限公司 | Ultrasonic signal detection circuit, ultrasonic signal detection method, and display panel |
| CN110716115B (en) * | 2018-06-27 | 2021-01-22 | 京东方科技集团股份有限公司 | Ultrasonic signal detection circuit, ultrasonic signal detection method, and display panel |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20080910 |
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| CX01 | Expiry of patent term |