37results about "Phantom key detection/prevention" patented technology

The invention relates to a key detection method and a device. The method is characterized by comprising the following steps: detecting a key to acquire a key signal; and carrying out the frequency-change sampling of the key signal, outputting a control signal when the frequency of sampling effective key signals reaches or exceeds a preset frequency, wherein the frequency-change sampling refers to the repeated process of progressively increasing a sampling frequency from a first frequency to a second frequency and progressively decreasing the second frequency to the first frequency, and preset time resides in each frequency of the sampling frequency. The invention decreases the interference frequency of the key detection by external signals.

An input apparatus using multidimensional electrodes to define key functions and the encoding method thereof is peculiarized by utilizing N-dimensional electrodes to define the individual key functions, where N is a positive integer number greater than two. The keyboard scan process according to the present invention is to perform the scan on the coordinate electrodes one by one and save the scan codes for making a synthetic determination, so as to identify the key being pressed. The keyboard encoder IC using the keyboard scan process of the present invention is advantageous to the pin number reduction and cost descent.

A logic circuit uses hardware to process keyboard scanning, more especially, a microprocessing system inputs the signal through a pressed key into a control circuit for conducting operation; since the column input end has electric resistance with higher driving ability than that of the row output/input end, a higher electric potential status is thereby obtained and conducted with the circuit through a pressed key to make the high and the lower electric potentials approach in accordance with each other and generate electric potential change, or through a converting method of automatically driving electric potential, the innovative effect of the present invention is achieved.

A keyboard includes plural keys, a membrane key switch module and plural diodes. The plural diodes are disposed on the membrane key switch module, and electrically connected with plural upper contacts or plural lower contacts of the membrane key switch module. Consequently, the keyboard has the function of avoiding the ghosting problem.

A keyboard control circuit for a keyboard having P keys includes an array module that includes P key switches, and a key-matrix having N scan lines that intersect M return lines to form N×M intersections, where P<N×M. The intersections include ghost key positions free of the key switches, and safe key positions being of a number at least equal to P. Each key switch is disposed at a corresponding safe key position. Each ghost key position cooperates with a corresponding group of first, second and third ones of the safe key positions to constitute four corners of a rectangle in the key matrix. A processing unit provides a scan signal to each scan line during a scan period, receives at least one scan line from the return lines in response to operation of at least one key switch, and outputs an input signal corresponding to operation of the at least one key switch.

A keyboard supporting N-key rollover (NKRO) is provided. The keyboard includes a first key data output module, which is coupled to a keyboard matrix for outputting an unlimited number of key data to a particular OS via a universal serial bus (USB) interface, and a second key data output module, which is coupled to the keyboard matrix for outputting a particular number of key data to any type of OS via the USB interface, synchronously

An input device with ghost key suppression includes a switch module, a comparator, an exchange unit, a bias voltage resistor, and a processing module. The switch module includes a plurality of strobe lines, a plurality of sense lines, and a plurality of switch units. Each of the switch units has a switch and a resistor connected in series between a corresponding one of the strobe lines and a corresponding one of the sense lines. The comparator is configured for comparing a signal received at an input end thereof with a reference signal for generating the comparison signal. The exchange unit is electrically connected to the sense lines and the comparator, and is operable in response to a control input for making and breaking electrical connection between each of the sense lines and the input end of the comparator. The processing module controls operation of the switch module and the exchange unit based on the comparison signal.

A computer keyboard which enables a computer to automatically recognize nomenclature information (ID) of keys is provided. Preferably, the keyboard contains a first memory which stores a table in which nomenclature information (ID) of keys and resistance values are associated with each other, a resistor having a resistance value substantially equal to any one of the resistance values, and a controller connected to the first memory and the resistor. The controller detects the resistance value of the resistor and reads the ID of the key corresponding to the resistance value from the table.

A keyboard scan circuit for a device receiving plural inputs simultaneously is provided. The scan circuit includes a plurality of keyboard input/output ports, each of which can be selected from a group consisting of an input mode, an output mode, and a floating mode for receiving one of a plural inputs, a plurality of rectangular matrices including a plurality of detectable input terminals and a plurality of synchronously detectable input terminals and formed by means of cross-linking the keyboard input/output ports, and a plurality of current-isolating elements electrically connected between the keyboard input/output ports and the rectangular matrices for mutually isolating signals of the rectangular matrices.

The invention relates in an aspect A to a method for determining active input elements (S1a, S2a) of an input arrangement (10), comprising

• • providing input elements (S1a to S2b) that are connected according to a matrix arrangement,
  • providing within the matrix arrangement at least two drive lines (L1, L2) that are each connected to a respective driving circuit (2, 4),
  • providing within the matrix arrangement at least two sense lines (Ca, Cb) that may be used to detect active input elements (S1a, S2a),
  • providing within the matrix arrangement serial connections (SC1 to SC4) each comprising one of the input elements (S1a) and a resistor (R1a) and each serial connection (SC1 to SC4) being connected to a respective one of the drive lines (L1, L2) and to a respective one of the sense lines (Ca, Cb),
  • providing pull resistors (Ra, Rb) that connect the sense lines (Ca, Cb) to a first potential, and
  • using a control device for the driving circuits that drives an active drive line (L1) to a second potential that is different from the first potential and that drives a non active drive line (L2) or non active drive lines to the first potential or to a potential having an absolute offset value from the first potential that is at most 50 percent or at most 10 percent of the absolute value of the difference of the first potential and of the second potential.

A keyboard apparatus including a key module and a detection circuit is provided. The key module includes a plurality of keys, a plurality of scan lines, and a plurality of return lines. The scan lines and the return lines are crossed to each other and coupled to the keys respectively. The detection circuit is coupled to the return lines and configured to detect a current flowing through each of the return lines and indicate that a switch of each of the keys is in an on state or in an off state according to a value of the current.

The present invention relates to a key input device and a portable mobile communication terminal using the same. First detection information relating to electrical connection with row signal lines and column signal lines is received from a key matrix circuit (S101). The first detection information is used to determine whether there is a possibility that three or more key switches are simultaneously depressed ON by a user and electrical connection relating to a key switch not depressed is erroneously detected (S108). If No, the first detection information is used to output information based on the key switch depressed ON by the user (S109). If Yes, the output based on the first detection information is suppressed.

Disclosed is a key operation device for detecting an open/close state of key switches using row and column signal lines. The key switches include: 1^st to 4^th key switches each corresponding to a key for inputting a direction; and ten-key switches correspond one-to-one to keys of a ten-key pad. The 1^st and 2^nd key switches are both coupled to one of the row signal lines and each to a different one of two of the column signal lines. The 3^rd and 4^th key switches are both coupled to another one of the row signal lines and each coupled to a different one of the two column signal lines to which the t and 2^nd key switches are respectively coupled. None of the ten-key switches is coupled to either of the two row signal lines to which the 1^st and 2^nd or 3^rd and 4^th key switches are coupled.

A keyboard apparatus including a key module and a detection circuit is provided. The key module includes a plurality of keys, a plurality of scan lines and a plurality of return lines. The scan lines and the return lines are crossed to each other and respectively coupled to the keys. The detection circuit detects a plurality of return voltages of the return lines and generates a plurality of detection signals accordingly so as to indicate that a switch of each of the keys is at an on state or at an off state. The detection circuit includes a plurality of P-type transistors. A first terminal of each P-type transistor is coupled to a ground terminal, a control terminal of each P-type transistor is directly coupled to a corresponding one of the return lines, and a second terminal of each P-type transistor generates and outputs one of the detection signals.

The present invention discloses a method and system for detecting hidden ghost keys on a keyboard matrix. The keyboard matrix is composed of multiple rows crossing with multiple lines that form multiple key-locating positions. The method comprises: selecting multiple preset keys from the matrix; detecting ghost keys among the matrix based on the selected preset keys; selecting multiple examining keys from the preset keys and the detected ghost keys, based on that at least one ghost key is included in the examining keys; and determining hidden ghost keys based on the examining keys. The system detects ghost keys among the matrix via a preset key selecting unit and a ghost key detecting unit, which selects multiple examining keys via an examining key selecting unit, and determines hidden ghost keys based on the examining keys through a hidden ghost keys detecting unit.

The invention discloses a method and an apparatus for ghosting suppression in a capacitive key matrix and touch pads. The apparatus includes a plurality of capacitive sensors arranged in a matrix on a substrate. A measuring circuitry measures the capacitance of each of a plurality of row lines and a plurality of column lines in the matrix coupled to the capacitive sensors. A first electrode is on the substrate on a first edge of the matrix and is proximal to a first corner of the matrix. The first electrode is coupled to the measuring circuitry. A second electrode is on the substrate on the first edge of the matrix and is proximal to a second corner of the matrix, the second corner opposing the first corner on the first edge. The second electrode is coupled to the measuring circuitry. The measuring circuitry determines the positions of two touches to the touch pad. Methods are disclosed.

A capacitive keyboard that can detect a key that has been depressed and the depressed amount thereof with high accuracy is provided. The capacitive keyboard includes a drive circuit 11 that alternatively switches the voltage of each of drive lines M from an L-level to an H-level, a sensing circuit 12 that detects the voltage generated in each of sensing lines N, and a control circuit 15 that detects, on the basis of the voltage value detected by the sensing circuit 12, the key that has been operated and the operation amount of the operated key. The sensing circuit 12 includes a peak hold circuit 32 that holds the peak value of the voltage that is input from a sensing line N over a predetermined period and an A/D conversion circuit 33 that converts the voltage held by the peak hold circuit 32 into a multi-stage digital voltage value.

An anti-ghost membrane switch device includes a first membrane layer, a second membrane layer, and a spacing layer. A first surface of the first membrane layer is provided with first trigger points and a first signal line. The first signal line is connected to the first trigger points and extends to a first output terminal. A second surface of the second membrane layer faces towards the first surface and is provided with second trigger points and second signal lines. Ends of the second signal lines are connected to the second trigger points. Another ends of the second signal lines extend to the second output terminal. The second signal lines are not electrically connected with one another. The first signal line of the first membrane layer and the second signal lines are not electrically connected with one another. The spacing layer is between the first and second membrane layers.