VUCKOVIC, Dusan (Rajiceva 1/25, Nis, RS-18000, RS)
PRIJIC, Aneta (Bulevar Nikole Tesle 17/6, Nis, RS-18000, RS)
PRIJIC, Zoran (Bulevar Nikole Tesle 17/6, Nis, RS-18000, RS)
VRACAR, Ljubomir (Starca Vujadina 20A, Nis, RS-18000, RS)
VUCKOVIC, Dusan (Rajiceva 1/25, Nis, RS-18000, RS)
PRIJIC, Aneta (Bulevar Nikole Tesle 17/6, Nis, RS-18000, RS)
PRIJIC, Zoran (Bulevar Nikole Tesle 17/6, Nis, RS-18000, RS)
| CLAIMS 1. What is claimed is the device which has the function of the key consisted of at least two printed circuit boards divided by at least one spacer which forms at least one cavity within the structure, characterized by within the cavity between the layers of printed circuit board should be at least one device that changes its electrical characteristics under the influence of the mechanical force which affects the surface, of at least one of the printed circuit board and that all of these electronic components that are necessary for work of the device are placed in the cavity between the layers of the printed circuit board. 2. The device according to the claim 1, characterized by the pressure sensor should be used within at least one of the cavity between the layers of the printed circuit boards. 3. The device according to the claim 1, characterized by the printed circuit board should be of polygonal shape with the connectors on at least one of its sides. 4. The device according to the claim 1, characterized by the wireless electronic circuits should be within at least one of the cavity between the layers of the printed circuit boards. 5. The device according to the claim 1, characterized by at least one of the printed circuit boards or at least one of the spacer should have the possibility of being elastically deformed under the influence of the mechanical force that is affecting the device. 6. The device according to the claim 1, characterized by at least one of the printed circuit boards presents the "power plane", meaning that the most of the conducting surface of the device is connected to the common power supply. 7. The device according to the claim 1, characterized by at least one of the printed circuit boards presents the "power plane", meaning that the most of the conducting surface of the device is connected to the common grounding. 8. The device according to the claim 1, characterized by the top printed circuit board, which is under the influence of the mechanical force, should be the casing made of electrically non-conducting material. 9. The device according to the claim 1, characterized by the top printed circuit board, which is under the influence of the mechanical force, should be the casing made of electrically conducting material. 10. The device according to the claim 1, characterized by the components for visual indication are placed within at least one of the cavity between the layers of printed circuit boards. 11. The device according to the claim 1 , characterized by the components for audio indication are placed within at least one of the cavity between the layers of printed circuit boards. |
TECHNICAL FIELD
This invention relates to the field of electromechanical engineering and realization of programmable keys.
BACKGROUND ART
Beside the fact that classical mechanical keys are relatively complex and expensive for mass production, they also have many disadvantages. First of all there is a problem of reliability in the field of industrial exploitation. High level of humidity, presence of various chemical vapors, speck of dust, etc. may decrease the duration and reliability of the keys. In order to produce keys that are resistant to humidity and dust, it is necessary to modify the production process for standard keys and introduce additional production steps for the purpose of adequate keys protection, whereby the problem of mechanical reliability is still present.
There are many protection techniques for classical keys in order to comply with standards for industrial application. Usually this is related to the sealing into the water-resistant enclosure, or coating using various protective materials such as rubber, silicone, etc. In the case when keys also have remote electronics nearby, it is necessary to provide additional protection for electrical components.
DISCLOSURE OF THE INVENTION
In order to have simple and cost-effective mass production of the robust key a new innovative design has been developed. The design is based on the usage of standard processes in the production of printed circuit board. The key is made of sensing elements and controlling electronics, where all the components are integrated between the layers of printed circuit board. This makes compact, hermetically closed key whose production is cheap and fast. The key produced in this manner presents the finished module ready for implementation into the adequate devices. DETAILED DESCRIPTION OF THE DRAWINGS
Figure 1 presents the cross-section of the key produced with the printed circuit board technology. The key consists of flexible top surface (101), sensing element (103), spacer (102), inner printed circuit board with electronic components (104), spacer (105) with the cavity (107) for components and bottom printed circuit board (108) with outer contacts (106).
Figure 2 presents the example of key construction with square shape (202) with contacts (201) on each side of the key.
Figure 3 presents the example of key construction with octagonal shape (302) with contacts (301) on each side of the key.
DETAILED DESCRIPTION OF THE INVENTION
In order to have simple and cost/effective mass production of the robust key a new innovative design has been developed. The design is based on the usage of standard processes in the production of printed circuit board (PCB) technology. The key is made of sensing element (103) which is placed under the top PCB (101). The sensing element is affected by the mechanical force applied on the top PCB (101) which modifies its characteristics. The components of the controlling electronics are placed within the cavity (107) between the two PCBs, where necessary space for their placement is provided with the spacer (105). The task of controlling electronics is to read the sensor ' s parameters and, on the basis of specific algorithm, to generate the signal which states that the key is pressed, as well as to provide the key programmability. The bottom PCB (108) is used as so called "power plane", meaning it is connected to the common grounding or to the common power supply. In this way the device has the electrostatic shield that protects the sensor ' s construction from external electrical fields which could disturb its operability. Additionally, the bottom PCB is used for placement of the contacting surfaces (106) which provide the integration of the key into final product. This type of the key design allows the construction of the compact, hermetically sealed key whose production is cheap and fast. The key produced in this manner presents the finished module ready for implementation into the adequate devices. Its programmability allows the change of working parameters by the final user.
Figure 2 and 3 present the examples of key construction in the shape of square (202) and octagon (302). The contact surfaces (201) and (301) placed onto the edges of the key are used for connecting the key with the surrounding where it will be exploited. Even though the square and octagonal shapes are suitable for keyboard formation consisted of multiple keys, this invention is not limited only for this geometrical shapes and they are given here as two of the possible solutions. Within the controlling electronics it is possible to integrate the audio and/or light indication of the key working mode and its present condition. In this manner better interaction with the user is achieved.