410results about "Dynamic coding" patented technology

When an array of proximity sensors is used as a keyboard, it can provide an ambiguous output if a user's finger overlaps several keys or if liquid is spilled on the keyboard. This ambiguity is reduced by an iterative method that repeatedly measures a detected signal strength associated with each key, compares all the measured signal strengths to find a maximum, determines that the key having the maximum signal strength is the unique user-selected key and then suppresses or ignores signals from all other keys as long as the signal from the selected key remains above some nominal threshold value.

An improved key matrix scanning technique conducts a first pre-scan on a first array of connections in a key matrix to identify any activated keys or buttons associated with the first array. A second sub-scan is conducted on a second array of connections in the key matrix but only for the connections in the first array that are detected as having activated keys.

The invention relates to a keyboard scanning circuit, comprising N vertical lines, N*N keys formed by N first horizontal lines and second horizontal lines, N I / O ports (in-out ports), N diodes, N resistors and a power supply VCC. The N vertical lines, N first horizontal lines and second lines are arranged in a matrix manner to form a plurality of cross points. The N*N cross points are arranged in a manner corresponding to the N*N keys. Each horizontal line is connected to an I / O port through a diode; and each second horizontal line is grounded. Each vertical line is connected to the power supply VCC through a resistor in an electric manner. The N first horizontal lines correspond to the N vertical lines respectively; each pair of horizontal line and vertical line corresponding to each other communicate with each other and no key is arranged on the N cross points between the horizontal line and the vertical line. The keyboard scanning circuit is capable to use N I / O ports to scan N*N keys, the structure is simple, I / O port resource is saved and the cost is reduced. Besides, a keyboard scanning method is provided.

A matrix keyboard circuit comprises N-numbered column lines, N-numbered first row lines, N*N-numbered keys, N+1-numbered elements with resistance, N-numbered diodes and a power supply, wherein the N-numbered first row lines are respectively connected on the power supply by the elements with resistance. The matrix keyboard circuit also comprises N-numbered I / O ports and grounded second row lines, wherein The N-numbered first row lines and the second row lines respectively intersect with the N-numbered column lines to form N*(N+1)-numbered matrix intersecting points; a diode is arranged on the intersecting point of each column line and a first row line corresponding to the column line; the cathode of the diode on one intersecting point is connected with the column line forming the intersecting point and the anode thereof is connected with the row line forming the intersecting point; the N*N-numbered keys are correspondingly arranged on other N*N-numbered intersecting points respectively; and the first end of a key on one intersecting point is electrically connected with the column line forming the intersecting point and the second end thereof is electrically connected with the row line forming the intersecting point. The invention also provides a scanning method of the matrix keyboard circuit.

An improved key matrix scanning technique conducts a first pre-scan on a first array of connections in a key matrix to identify any activated keys or buttons associated with the first array. A second sub-scan is conducted on a second array of connections in the key matrix but only for the connections in the first array that are detected as having activated keys.