CN101888235B - Projection touch key - Google Patents

Abstract

The invention discloses a projected touch button, which includes a button projection module, a capacitive field strength detection module, and a control module; the button projection module includes an operation board, a circuit board, and at least one actual button position and its corresponding operation button position, The operation panel and the circuit board form an included angle of 0°～90°. The actual key position is located on the circuit board, the operation key position is located on the operation panel, and the operation key position is in the projection area of the actual key position on the operation panel. The actual key position The distance from the operation button is less than 20 cm. The actual key position is connected to the input end of the capacitance field strength detection module, the output end of the capacitance field strength detection module is connected to the input end of the control module, and the capacitance field strength detection module detects the change of the capacitance field strength between the actual key position and the operation key position And send it to the control module, and the control module processes the keys. The invention realizes the separation of the button operation panel and the PCB board.

Description

Projected touch button

technical field

The invention relates to a touch button, in particular to a projected capacitive touch button, which belongs to the technical field of touch buttons.

Background technique

Touch buttons have been developed for many years. The touch-sensitive operation panel has the advantages of firmness, wear resistance, insulation, dust isolation, and water isolation, and its appearance is beautiful and novel. However, due to cost and stability reasons, it has not become popular in electronic devices until recent years. Especially in some home appliances, the advantages of touch buttons are more obvious, and it has become a popular technology in recent years. The capacitive touch key widely used at present adopts the principle of capacitive sensing, which can detect the touch of a finger through a shell of insulating materials such as glass and plastic with a thickness of 15 mm. Most of the capacitive touch keys adopt the human-computer interaction method, that is, the operator directly touches the key position corresponding to the PCB circuit board to trigger the key operation, which will easily cause long-term touch wear and tear, thereby affecting the service life of the key. At the same time, the back of the existing touch-sensitive button panel is directly connected to the processing circuit, which requires high production technology, troublesome maintenance and replacement of the button panel or circuit board, and poor scalability. More importantly, people are more and more pursuing the fashion and beauty of modern technology products while paying attention to the quality of electronic information products. If the operation panel of the touch button can be made transparent, and a beautiful and fashionable button pattern , will be able to meet users' pursuit of fashion and novelty of modern technology products, thereby stimulating their interest and demand for products. However, the back of the existing touch-sensitive key panel is directly connected to the processing circuit PCB, which cannot solve the technical problem of developing a transparent key operation panel.

Contents of the invention

The purpose of the present invention is to provide a projected touch key, which realizes the separation of the key operation panel and the PCB circuit board, and realizes key identification by changing the capacitive field strength between the actual key position and the operating key position.

The purpose of the present invention is achieved through the following technical solutions:

A projected touch key, including a key projection module 1, a capacitive field strength detection module 2, and a control module 3; the key projection module 1 includes an operation panel 4, a circuit board 5, and at least one actual key position 6 and each The operation button position 7 corresponding to the actual button position 6, the operation panel 4 is made of non-conductive material, the operation panel 4 and the circuit board 5 form an included angle, the range of the included angle is 0°～90°, the actual button position 6 , the capacitive field strength detection module 2, the control module 3 are located on the circuit board 5, the operation key position 7 is located on the operation panel 4, the operation key position 7 is in the projection area of the actual key position 6 on the operation panel 4, and the actual key position The distance between position 6 and operation button position 7 is less than 20 centimeters; the actual key position 6 is connected with the input end of capacitance field strength detection module 2, and the output end of capacitance field strength detection module 2 is connected with the input end of control module 3, and the capacitance The field strength detection module 2 detects the change of the capacitive field strength between the actual key position 6 and the operation key position 7, and transmits the change amount to the control module 3, and the control module 3 performs related key processing.

The object of the present invention can also be further realized by the following technical measures:

For the aforementioned projected touch key, a shielding ring 8 is provided on the outside of the same plane as the actual key position 6 .

In the aforementioned projected touch key, the capacitive field strength detection module 2 uses a dedicated capacitive touch IC chip.

Compared with the prior art, the beneficial effect of the present invention is: the separation of the key operation panel and the PCB circuit board is realized, thereby reducing the manufacturing process requirements for the touch screen, and the maintenance and replacement of the key panel or the circuit board are easy. When in use, the keys can be triggered spatially, allowing users to have a fresh and magical operating experience.

Description of drawings

Fig. 1 is a circuit structure diagram of the present invention;

Fig. 2 is a structural diagram of the button projection module of the present invention;

Fig. 3 is a single IC chip capacitance field strength scanning circuit structural diagram of the present invention;

Fig. 4 is a structure diagram of a plurality of IC chip capacitance field strength scanning circuits of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in FIG. 1 , the present invention includes a button projection module 1 , a capacitive field strength detection module 2 , and a control module 3 . As shown in FIG. 2 , the button projection module 1 includes an operation panel 4 , a circuit board 5 , and several actual button locations 6 and operation button locations 7 corresponding to each actual button location 6 . In this embodiment, there are six actual key positions and corresponding operation key positions, which are respectively used to control the TV volume increase and decrease, channel selection, power control, and menu control functions. The operating panel 4 and the circuit board 5 form a certain angle, which is 45° in this embodiment. The actual button position 6, the capacitive field strength detection module 2, and the control module 3 are installed on the circuit board 5, and the actual button position 6 is made of a conductor. In order to prevent mutual interference between a plurality of buttons, each actual button position A shielding ring 8 is provided on the outside of 6 and is installed on the circuit board 5 . The operation key position 7 is located on the operation panel 4, and the operation key position 7 is in the projection area of the actual key position 6 on the operation panel 4. In this embodiment, the operation panel 4 is made of transparent plexiglass, and the operation key position 7 is printed with corresponding Button sign. The distance between the actual key position 6 and the operating key position 7 is 10 centimeters. The above structure realizes the separation of the key operation panel and the PCB circuit board. The actual key position 6 is connected to the input end of the capacitance field strength detection module 2, the output end of the capacitance field strength detection module 2 is connected to the input end of the control module 3, and the capacitance field strength detection module 2 detects the actual key position 6 and the operation key The change of the capacitance field strength between the bits 7, and the change amount is transmitted to the control module 3, and the control module 3 performs related button processing. In this embodiment, the capacitive field strength detection module 2 uses a dedicated capacitive touch IC chip, and the control module 3 is an MCU chip with an interface for serial asynchronous communication. As shown in Figure 1, the user does not directly touch the actual key position 6 when using it, but touches the key position 7. The human finger and the actual key position 6 made of a conductor form a certain capacitance, and the special capacitive touch IC chip is scanned. Detect the change of the capacitive field strength between the two, convert the change of the capacitive field strength into a digital quantity through AD and send it to the MCU central processing unit chip, the button system can judge the user's action command, and then perform button trigger processing and output. The aforementioned shielding ring 8 is provided outside the actual key position 6 to divide the triggering areas of different keys so as to avoid misoperation. In fact, the user does not need to actually touch the operation button position 7 when using it, as long as the finger enters the sensing space area of the button according to the guidance of the button symbol, the button can be triggered to work in the air. Simultaneously, since the actual button position 6, the capacitive field strength detection module 2, the control module 3, etc. are installed on the circuit board 5, and the operation panel 4 is made of transparent plexiglass or ABS, there is no circuit under the transparent operation panel 4 , allowing users to have a fresh and magical operating experience.

As shown in FIG. 3 , in specific implementation, a single capacitive touch IC chip can be used in conjunction with a digital logic switch to realize the scanning of changes in the capacitive field strength of the button. Each actual button position on the PCB circuit board is connected with a digital logic switch, and the digital logic switch is connected with a dedicated capacitive touch IC chip. The capacitive field strength variation of the corresponding button is converted by AD, and then the converted data is sent to the MCU central processing chip for corresponding button processing. This solution only uses one capacitive touch IC chip, which saves cost.

As shown in Figure 4, another implementation method of the scanning circuit for capacitive field strength changes is that each actual button position on the PCB circuit board is directly connected to a dedicated capacitive touch IC processing chip, and each capacitive touch IC chip is responsible for detecting the corresponding button. The capacitive field strength changes, and multiple dedicated capacitive touch IC processing chips are respectively connected to the MCU central processor, and the MCU central processor realizes scanning of multiple IC chips and receives data sent by the IC chips. There is also a capacitive field strength change threshold in the dedicated capacitive touch IC processing chip. Only when the capacitive field strength change triggered by the user's finger touch operation button is greater than the preset field strength threshold, the capacitive touch IC chip can recognize the user's action. Instructions, the MCU compares multiple data sent by the IC chip through a certain algorithm, and determines that only the key with the largest change in capacitance field strength is triggered, and other keys are not triggered, and recognizes effective operations and misoperations, so as to perform corresponding key processing .

In addition to the above-mentioned embodiments, the present invention can also have other implementations, and all technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims (3)

1. a projection touch key is characterized in that, comprises button projection module (1), capacitor field intensity detection module (2), control module (3); Said button projection module (1) comprises operation panel (4), circuit board (5); Also comprise at least one actual key position (6) and the operation push-button position (7) corresponding with each actual key position (6); Operation panel (4) is by the non-conducting material manufacturing, and said operation panel (4) and circuit board (5) have angle, and the scope of this angle is 0 °～90 °; Said actual key position (6), capacitor field intensity detection module (2), control module (3) are positioned on the circuit board (5); Operation push-button position (7) is positioned on the operation panel (4), and operation push-button position (7) are in the view field of actual key position (6) on operation panel (4), and the distance of said actual key position (6) and operation push-button position (7) is less than 20 centimetres; Said actual key position (6) links to each other with the input of capacitor field intensity detection module (2); The output of capacitor field intensity detection module (2) links to each other with the input of control module (3); Capacitor field intensity detection module (2) detects the variation of capacitor field intensity between actual key position (6) and operation push-button position (7); And sending variable quantity to control module (3), the button that control module (3) is correlated with is handled.

2. projection touch key as claimed in claim 1 is characterized in that, the conplane outside, said actual key position (6) is provided with shading ring (8).

3. according to claim 1 or claim 2 projection touch key is characterized in that, said capacitor field intensity detection module (2) uses special-purpose capacitance touch IC chip.

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