Abstract: The keyboard modification system includes: a looping module; a keycode processing module; a determining module; and, at least one additional keycode processing module. The looping module checks for the existence of incoming data from a communication port of a PDA and provides a keycode data output therefrom. A keycode processing module receives the keycode data output from the looping module and translates the data into variable data. A determining module determines whether a key on a keyboard of a portable keyboard assembly has remained depressed and if not continues to check for the existence of the variable data and translate the variable data to a keydata stream. The additional keycode processing module replaces the keydata stream with a different keydata stream if the key has remained depressed.

Abstract: A key switch signal recognition circuit including a plurality of key switch buttons, a plurality of key switch signal output lines, and a plurality of key switch button contact areas is disclosed. Each of the key switch contact areas includes a first wire set and a second wire set. The first wire set has at least one wire, and each wire of the first wire set has one end connected to a common line and an opposite end forming an open end. The second wire set has at least one wire respectively disposed in parallel to and electrically insulated from the wire of the first wire set. The wire of the second wire set is respectively connected to a key switch signal output line.

Abstract: Systems and methods for input of text symbols into an electronic device comprising a reduced keyboard having keys representing a plurality of characters are disclosed. Possible symbol variants are identified based on character inputs received from the reduced keyboard. Each identified symbol variant is grouped into one of a plurality of groups of symbol variants, each group having an associated priority, according to a type of the symbol variant. Within at least one of the groups, the symbol variants are ranked in decreasing order of frequencies of use of the symbol variants. A list of symbol variants comprising the plurality of groups of symbol variants in order of decreasing priority is then displayed, and an input symbol is selected from the list of symbol variants. The symbol variants of the at least one of the groups of symbol variants are thereby sorted by both priority and frequency of use.

Abstract: The invention that discloses a switching device for common keyboard, screen, and mouse can make several sets of computer hosts (CPUs) alternatively use a keyboard, a screen, and a mouse, etc., and through the invention, any set of computer may be chosen to be connected to those keyboard, screen, and mouse. The invention includes a human interface device processing unit, a compiler, a multiplexer, and a hub. The human interface device processing unit may process the signal of a human interface device (HID). The compiler has a firmware to receive the signal output from the human interface device processing unit. The multiplexer is controlled by the signal output from the compiler to decide in choosing which computer host to be connected. The hub is controlled by the human interface device processing unit to be acted as a signal assembly-and-transmission.

Abstract: A variable function calculator utilizes a fixed program memory array such as a programmed read only memory in which a number of programs are stored depending upon the desired functions of the calculator. The calculator also includes a program counter, an instruction register, control decoders, jump-condition circuits, a clock generator, a timing generator, digit and FLAG mask decoders, key input logic, a register and FLAG data storage array, a decimal and FLAG arithmetic logic unit, an output decoder, and a digit scanner which scans both the keyboard and display outputs. Aside from providing basic desk top calculator functions, the read only memory may be programmed so that the system provides metering functions, arithmetic teaching functions, control functions, etc.. A preferred embodiment of the invention is capable of being fabricated as a monolithic integrated semiconductor system utilizing contemporary metal-insulator-semiconductor techniques.

Abstract: A configurable computer input device. At least one switch is removably attachable to a surface and is in communication with a processor. At least one function is assignable to activation of the switch. The at least one switch may be repositioned distances smaller than a length or width of the at least one switch. Circuitry is in communication with the at least one switch for assigning at least one function to activation of the switch. Circuitry communicates the at least one function to a host computer. Circuitry determines the actuation status of the at least one switch and communicates the actuation status to the host computer.

Abstract: An arrangement of a plurality of status keys in a keyboard for entering information in an electronic device. The keyboard comprises a plurality of regular keys connected to a resistive strip at a plurality of locations for providing a first signal when one of the regular keys is pressed and the first signal is indicative of the location associated with the pressed regular key; a plurality of resistors, each having a different resistance, connected in series to the resistive strip, and separately connected in parallel to the status keys so that the resistors can be selectively by-passed by pressing one or more status keys, wherein a second signal is provided when one of the regular keys is pressed together with at least one status key, and wherein the second signal is indicative of the resistance the status key for identifying the pressed status key.

Abstract: A control apparatus for a built-in keyboard in notebook computers includes an keyboard encoder which has a serial/parallel port interface to transmit a keyboard scan code to a keyboard controller and to receive commands from the keyboard controller. The keyboard controller is integrated in a core-logic chip set. The keyboard encoder also includes a series bus interface to download matrix value pre-stored in the core-logic chip set to the keyboard encoder.

Abstract: 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.

Abstract: A keyboard switch matrix arrangement provides keyboard key discrimination utilizing simultaneous groupings of drive line combinations and sense line combinations (time division multiplexing) to discriminate between keyboard keys with substantially fewer total drive and sense lines than a conventional switch matrix, thereby substantially reducing the number of required IC pin connections. The invention permits given sense lines to sense more than one drive line for a valid key press duration (i.e., key actuation), and given drive lines to drive more than one sense line for a given valid key press duration. In this manner, and through utilization of time division multiplexing, the switch capacity of a matrix with a given number of drive lines and sense lines can be substantially increased.

Abstract: A controlling apparatus for programming extended code of keyboard and a method for the same. The keyboard receives an extended code processing command and judges the extended code processing command to be used for enabling a second key code or disabling a second key code of the key. The keyboard also receives key code setting parameters. The keyboard has a mode selection key to toggle the keyboard between a standard key code mode and an extended key code mode. Therefore, all keys on the keyboard can be assigned with new extended code or disabled for the new extended code to broaden the function thereof.

Abstract: A self-identifying keyboard is provided with customization logic which allows the keyboard processor to assign a keyboard identification (ID) value. The keyboard processor is interconnected to a data channel interface adapted to communicate with a host system. The host system can send a query for the ID value, via the data interface, and the keyboard processor can retrieve the ID value from a non-volatile memory, and transmit it back to the host system via the data channel interface. This customization approach simplifies system integration, by letting the host system automatically learn the keyboard type. The ID value may indicate a particular language of the keyboard. At the time of final system assembly, the same host system, or another suitably programmed manufacturing system can be used to assign the keyboard ID, when it is known what language or other unique functionality is used in the end-user product.

Abstract: An IACK keypad with independent key regions arranged in an array of multiple rows and columns, and combination key regions defined between rows and columns of the array of independent key regions. A trace matrix underlying the keymat either includes, in addition to normally isolated column traces and row traces underlying the independent key regions, trace extensions extending from the row and column traces to underlie the combination key regions, or additional row and column traces underlying the combination key regions and tied to other row and column traces. The trace extensions extend to within a contact region of an opposed electrical contact, such as on a snap dome, beneath the combination key region. Independent and combination key snap domes are constructed to insure singular tactile feedback during combination key operation.

Abstract: A USB-compliant keyboard device is provided that is capable of preventing malfunctions, operation failure and the like due to static noise by a simple method. The keyboard device has a keyboard main body with a large number of key tops on its upper surface, an upper case and a lower case accommodating the keyboard main body, a control circuit board on which a control circuit to control the keyboard main body is mounted, and USB connectors connected to the control circuit board. Further, a shield plate covering the control circuit board from a lower position is provided. The shield plate is electrically connected to frame ground members of the USB connectors and a shield line of a cable connected to a personal computer main body.

Abstract: 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.

Abstract: An apparatus for powering on a terminal with a keypad by randomly selecting any key of the keypad. The keypad includes a plurality of keys, each of which has contacts of two contacts.

Abstract: In place of a conventional n×m sense line/drive line matrix for keyboard key detection, discrimination between keyboard keys is carried out with one or more current divider or voltage divider circuits, with the result that the number of necessary IC pin connections may be reduced. The keyboard key switches are arranged into one or more current divider or voltage divider circuits. In a current divider embodiment, the key switches of each circuit are arranged in parallel with each other at respective points along a resistive switch line extending from Vcc to ground. When closed by key depression, the switches provide shortened paths from Vcc to ground, thus resulting in a current division effect. A voltage along the line is input to an A/D converter of a micro-controller which performs keyboard key discrimination.

Abstract: In a method of processing a multi-function key in a key inputting device, such as a multimedia keyboard, the scan code value of the multi-function key consists of the “windows key code” as a first value, one or more code keys of “ctrl”, “alt” and “shift” as a second value, and “a selected key code” as the third value, thereby forming a scan code value of the multi-function key being made to not overlap with a normal key or a combination of the normal keys, thereby preventing any collision or overlapping of codes, and ensuring the stability of the key codes.

Abstract: A wireless keyboard may be provided with a guard protocol which prevents unintended typematics. An alive signal may be periodically generated to advise a host processor-based system that the keyboard communication link is still effective. If the host processor-based system receives a key make signal but does not receive a break signal or an alive signal, the processor-based system may deduce that the link has gone inactive, and may generate its own break signal. This avoids unnecessary power consumption and unnecessary typematics.

Abstract: The present invention relates to an integrated circuit (IC) device for a wireless keyboard array that concentrates the circuital functionalities of an oscillation circuit, a transmission/receiving circuit, an array detector, a signal processor, a coder, a decoder, an array decoder, et cetera, to be manufactured as a wireless keyboard array IC to enable the keyboard simultaneously to simultaneously conduct the code transmission and the receiving of the decoding as well as output the signal data keyed in from the keyboard to a keyboard controller by the method of serialization and via the emitting circuit and receiving circuit, then the keyboard controller transmits the signal data into a computer for increasing the practical value of the economic efficiency.

Abstract: A shared interface device provides connection between a portable electronic device and a peripheral unit. The shared interface device comprises a switch and an energy-storing element. The switch has a terminal connected to a T×D/POWER pin of the portable electronic device and an R×D pin of the peripheral unit, and another terminal connected to a VCC pin of the peripheral unit. The switch is ON/OFF when the T×D/POWER pin of the portable electronic device is HI/LO. The energy-storing element has one end connected to another end of the switch to supply electrical power to the peripheral unit and another end connected to ground. The energy-storing element is charged when the switch is ON and used as a backup power supply when the switch is OFF.

Abstract: A keyboard has a processor, a scan matrix coupled to the processor, a first set of keys coupled to the scan matrix, a logic control circuit, and a second set of keys coupled to the logic control circuit. The processor decodes the identity of a pressed key from the second set of keys via the logic control circuit.

Abstract: A computer keyboard has multiple input/output function and is connected to a computer (or a set-top box). The keyboard comprises a keyboard main body, and a handset slot. The keyboard main body has a control circuit, a scan matrix circuit connected to the control circuit; a first switch and a second switch. The control circuit is connected to the normally-close terminals of the first switch and the second switch. The communication interface (such as USB or RS-232) of the keyboard is connected to the normally-open terminals of the first switch and the second switch. The common terminal of the first switch is connected to the handset slot and the internal circuit of the handset. The common terminal of the second switch is connected to the internal circuit of the computer. The keyboard main body has function key set connected to the control circuit when being pressed.

Abstract: A keypad arrangement is disclosed comprising a scanning unit (30) having a certain number of port line terminals (1 to 11) and a number of sensor cells (21) arranged in half-matrix structure having rows (23) and columns (22) whereby the number of columns (22) and the number of rows (23) each are less than the number of port line terminals. In comparison to normal detection systems, the given detection system allows a significant reduction of the port line terminals required to scan a given number of sensor cells. The device described is preferably applicable in communication devices.

Abstract: A key-pressing circuit has a control unit, a first charge storage circuit, and a key matrix circuit. The control unit has a controlling port and a detecting port, and the controlling port can be in either a grounded state or a floating state. The first charge storage circuit has a charging port that connects to the detecting port of the control unit. The key matrix circuit has a plurality of resistors and an associated plurality of switches. The resistors are connected together in series, forming a series resistor circuit that has a first end and a second end. One end of each switch connects to an end of its associated resistor. The other end of each switch connects to the controlling port of the control unit. The first end of the series resistor circuit connects to the charging port of the first charge storage circuit. The detecting port detects if the charging port of the first charge storage circuit reaches a predetermined voltage.

Abstract: A method of detecting short-circuits of a keyboard is provided. The method includes the steps of establishing a database of standard scanned codes and a keyboard matrix that corresponds to keys of a keyboard in the memory device of a computer mainframe and then predefining a set of 25 keys of the keyboard for detection purpose. When a tester presses one of the predefined keys, in the keyboard matrix a row of data line and a column of data line will connect with each other, allowing a keyboard controller to receive a signal variation responsive to the pressed key and then to produce a scanned code responding to the pressed key. After that, the scanned code is transmitted into the buffer of computer mainframe, triggering an interrupt IRQ1 in computer hardware. By executing a comparison program in the memory device of the computer mainframe, the computer mainframe compares the transmitted scanned code in the buffer with the data in the database stored in the memory device.

Abstract: Ideographic keyboard and method in which an array of characters are printed on one side of a panel and optically readable data corresponding to the characters is recorded on the other side of the panel. A character selector is moved about the first side the panel for selective alignment with the characters, and an optical reader is linked to the character selector for movement about the recorded data in concert with the character selector. The data corresponding to a selected character is read, and a coded signal for the selected character is output in response to the data which is read. In one disclosed embodiment, the data is recorded in the form of bar coding, and the reader is a bar code reader. Precise alignment of the reader with the data for the selected character is assured by reading data from a region larger than the data field itself and extracting the character data in software.

Abstract: A 3D electronic data input device with a key mapping card which changes from the prior 2 dimensions layout to 3 dimensions layout, has input keys and a mouse mounted on different sides of the keyboard. It also has electronic circus and connection devices. The key mapping card plays critical role to help users to find needed keys. There are several different sizes of the said keyboards to accommodate different hand sizes. The keyboard can hold and even be integrated with electronic device such as PDA.

Abstract: A method for switching among a plurality of key functions allocated to a special key, whereby the occurrence of a phenomenon that is contrary to a user's intent can be prevented. When a key event detector 14 detects the depression of a special key, it sets a register 18 by which a request is asserted to output a make scan code that is supposed to be output when the special key is independently depressed and that is originally allocated for the special key. A key event analyzer 15 and a code generator 16 output a scan code to carry out a predetermined key function in response to the depression of a key. But if the register 18 is set when the special key is released, the key event analyzer 15 and the code generator 16 output the above described make scan code.

Abstract: A key matrix circuit has a switching circuit with a first terminal and a second terminal that are switched on and off by pressing a selection key of a plurality of selection keys arranged in an N-row-by-M-column matrix, thereby making connection to a common ground circuit when a selection key is pressed. The key matrix circuit has a first voltage-dividing circuit connected between a connection circuit that connects the first terminals of the first row and a fixed power supply voltage, and a second voltage-dividing circuit connected between a connection circuit that connects the second terminals of the first column and the fixed power supply voltage, the connection points between resistances to of the first voltage-dividing circuit being connected to the connection circuits connected to the first terminals of the other rows, and the connection points between resistances of the second voltage-dividing circuit being connected to the connection circuits of the other rows.

Abstract: An antenna system for a radio frequency (“RF”) wireless keyboard includes a metallic plate as a part of the antenna system. The metallic plate is located within the wireless keyboard. A RF transmitter is coupled to the metallic plate and an antenna wire which form an the antenna loop. The antenna loop may also be directly integrated into the metallic plate by creating a cut-out space in the metallic plate. The antenna system may also include the metallic plate directly coupled with the RF transmitter so that the metallic plate is a whip or dipole antenna. The RF transmitter generates RF signals associated with particular keyswitches of the wireless keyboard. The antenna system transmits the generated RF signals to a RF receiver that resides separately from, and that communicates with, the wireless keyboard.

Abstract: An electronic device includes a keypad and a sensor that indicates proximity of a user to the electronic device, whereupon the keys of the keypad are illuminated. In particular, when the distance between the user and the sensor is less than a predetermined threshold, the keypad is illuminated in anticipation of the user providing keypad input to the electronic device. The sensor can be an infrared, an ultrasonic or a capacitive sensor. Alternately, the sensor can indicate contact between the user and the sensor, wherein the contact does not provide keypad input to the electronic device, for example, when the user touches but does not push a key of the keypad.

Abstract: A new apparatus for reading keyboard-commands of a portable computer comprises a shift register, a keyboard-matrix circuit, a filter, a buffer, an address generator, a mapping device, a comparator, and an output device. The shift register is for outputting a plurality of scan-input signals and a reference signal. The keyboard-matrix circuit is for outputting a scan-output signal according to the scan-input signals. The keyboard-matrix circuit includes a plurality of nodes corresponded to the keyboard buttons, respectively. The filter is for filtering the noise of the scan-output signal. The buffer is for further stabilizing the filter signal. The address generator is for reading the location of the node corresponding to the button being pressed. The mapping device is for outputting a mapping signal corresponding to the button being pressed. The comparator is for outputting a comparing signal, which represents the command corresponded to the pressed button.

Abstract: An apparatus and method is disclosed for providing a fast, low power consumption, detection of at least one depressed key in a resistive matrix keyboard. The common contact of each row of a resistive matrix is connected to a first input of each of a plurality of analog/digital comparators capable of switching between high and low voltage states. A common predetermined reference voltage is applied to a second input of each analog/digital comparator using a digital to analog converter. The output of a analog/digital comparator is in a first state if the voltage level applied to the first input is higher than the reference voltage, and in a second state if the voltage level applied to the first input is lower than the reference voltage. The reference voltage is varied to identify which analog/digital comparator has experienced a change of state.

Abstract: Character input control equipment enables the decrease of moving distance of a cursor between key positions and also enables efficient key input. The character input control equipment includes character input display field display controller for displaying a plurality of character input display fields in a display part, cursor movement controller for specifying one character input display field out of the plurality of character input display fields displayed in the display part by moving the cursor, and input character selector for selecting one character out of the plurality of characters corresponding to the one character input display field specified by the cursor movement controller wherein a plurality of characters correspond to each one of the plurality of character input display fields.

Abstract: A dual-function keyboard with two operational modes, a typing mode and a pointing mode. In the typing mode, each visible key functions as in a standard keyboard. In the pointing mode, all the keys function as pointer controllers. The keyboard also employs a novel “one-hot-encoding” circuitry that simplifies the wiring while allowing digital detection of any number of keys that are simultaneously depressed. The keyboard may be made of flexible materials and may be rolled-up or folded for easy transportation.

Abstract: Each keyboard key is marked with a self-defining indicator. A matrix of key sensing circuits for the keyboard are configured to detect this indicator when the keys are depressed and provide an output to a keyboard controller which in turn provides key signals to the keyboard's connector that is indistinguishable by a computer system from the output of a standard QWERTY keyboard. This enables the disabled user to carry this keyboard from one computer system to another and simply exchange it for the standard keyboard for the computer. There are no changes required to be made to the computer's operating system or any software of the computer in order to allow the disabled user to use the computer. Furthermore, other users are not required to reconfigure the computer system after the standard keyboard has been re-installed.

Abstract: A nodal point arrangement of keys on a keyboard comprises a nodal point layout of 8 rows and 16 columns, having 144 nodal points, some of the nodal points for switching with single key pressing, and rest of the nodal points for switching with two or more keys pressing. RCTRL and LCTRL are lined up in a row or a column to form a set. RSHIFT and LSHIFT are lined up in a row or a column to form a set either. RALT and LALT are lined up in a row or a column to form a set either. These three sets are disposed at the row or the column different with each other. APP is disposed at a row or a column same as either one of said three set. Fn is not allowed to locate at a row or a column same as RCTRL, LCTRL, RSHIFT, LSHIFT, RALT, LALT, and LWIN.

Abstract: A keyboard is placed into a suspend mode. Upon the detection of the pressing of a key, the keyboard processor is wakened from the suspend mode. No power is consumed during the suspend mode, sine the keyboard processor is not scanning the key matrix. The key matrix drive circuitry may also be tested by monitoring a signal emanating from the key matrix drive circuitry and scanning each of the drive lines in the key matrix. If the signal is altered, then the associated drive line in the keyboard drive circuitry is defective. Testing of sense circuitry is performed by changing pull-up resistors to pull-down resistors and then reading sense lines.

Abstract: Scan codes from an input device, such as a keyboard, are intercepted before being mapped to the operating system virtual key codes and instead are mapped to virtual key codes on an Abstract Virtual Keyboard. The Abstract Virtual Keyboard (AVK) supports scan codes for every known keyboard so the operating system could support multiple instances of input devices which were heretofore incompatible. The AVK vKeyCode is then passed through a filter if one is available for the AVK vKeyNumber. Next, a country language layout is called for the appropriate country and plugged into the AVK and the AVK vKeyNumber is entered. If an operating system (OS) virtual key code is returned, the system processes the OS virtual key code into a function or a character in the conventional manner. If no OS virtual key code is returned, another filter method is called to construct a key event. After an OS virtual key code is constructed from the filter, the operating system processes that code.

Abstract: A security keyboard matrix scanning method for a keyboard is disclosed. This invention utilizes bi-directional input/output ports, in which each line of the X-port and the Y-port can be selectively designated as a sensing line or an output line, to construct the X-port and Y-port such that at least one line of one of the two ports can output a scanning signal representative of a dummy scanning signal at the time the actual scanning signal is output from another line of either port. Thus, the scanning method disclosed in this invention can efficiently prevent a password from being recognized by a third party for illegal use thereby enhancing the security of a password identification device.

Abstract: The invention is, in its various aspects, an apparatus and a method for scanning a keypad or a keyboard. The apparatus comprises a keypad and an integrated circuit. The keypad includes a plurality of chained resistors and a plurality of key switches. Each of the plurality of key switches is tied to a common node at a first terminal thereof and tapping the chained resistors at a second node thereof. Each of the key switches generates a signal indicative of the respective key switch being pressed when the key switch is pressed. The integrated circuit is capable of receiving the generated signal. The integrated circuit furthermore includes an analog to digital converter capable of generating a reference signal and a circuit capable of determining which key switch has been pressed from the magnitude of the generated voltage signal and the reference signal.

Abstract: An apparatus and a method for increasing the number of keys in a ready made key-matrix , it is necessary to increase some extra diodes and change the keyboard scanning method . To increase some extra keys in the key-matrix, the diodes are in series with the keys, and the keyboard scanning method is executed by detecting the conductive direction of the diodes. The method avoids redesigning any IC to increase I/O ports, therefore, it can save the cost of redesigning and advance the sale.

Abstract: A keyboard having fewer keys than the characters available utilizes linked sequences of keystrokes in generation of some characters. Other characters may be produced with one keystroke. The difference between linked keystrokes and independent keystrokes both made in sequence is determined by either the length of the interval between keystrokes or use of a delimiting key. A threshold level for the interval between keystrokes which decides whether two sequential keystrokes are linked or not may be set by the user or may be automatically determined with the use of an adaptive predictive algorithm. It is generally suggested that pairs of keys be linked, particularly adjacent pairs of keys in a fixed configuration, and that the characters generated by either a single keystroke of a given key or the characters generated by two linked keystrokes be represented upon the keyboard in a disposition which facilitates intuitive learning of the keyboard.

Abstract: A computer implemented method for allowing the entry of text in any number of languages using any keyboard chosen by the user. The computer implemented method monitors a user's keystrokes detecting the entry of multiple identical consecutive keystrokes of any diacritical character in a predefined set of characters, then maps the keystrokes to replacement characters. A diacritical character is a character with diacritical variations that change the sound or accent of that character. A predefined set of characters is that set of characters defined as the characters in a predefined or selected language that have diacritical variations. Thus, once multiple identical consecutive keystrokes of any key are detected, the method determines whether the multiple keystrokes are of a diacritical character or whether they are of some other character.

Abstract: A keyboard has key positions providable with keys. A number of the key positions are actually provided with keys, whereas at least one other key position has a mode setting option. The mode setting option provides a feature that is readable by a microprocessor connected to the keyboard. Such features include pulse dialing parameters such as a pulse rate, a pulse width, and a pulse pause, or tone dialing parameters, or the like.

Abstract: A keyboard with key codes switchable by means of a single modifier key and a method of control thereof are provided. When a modifier key such as an Alt key, a Ctrl key, or a Shift key is pressed and then immediately released, the set of key codes is switched to another if no other modifiable key stroke is inserted during the press-and-release operation. Consequently, multimedia hot keys will be obtained by switching the key code set to another set of key coding that represents individual multimedia functions.

Abstract: A digital cordless telecommunications unit that serves for communications when paired with a similar unit and connected with a network is disclosed. The unit receives and transmits analog voice signals and also transmits digital baseband signals and receives digital formatted baseband signals. The unit includes a baseband chip, as well as an audio functions block and a system control functions block. The audio functions block comprises an audio front end for receiving and transmitting the analog voice signals and an adaptive differential pulse code modulator codec, connected to the audio front end. The codec converts the analog voice signals to the digital baseband signals and converts the digital formatted baseband signals to the analog voice signals for transmission.

Abstract: A five-switch keypad apparatus having four diodes that multiplex the switch contacts onto three sense terminals. The three sense terminals create a binary code that defines eight possible switch states. The eight states are used to indicate each individual switch closure, a lack of a switch closure, and two simultaneous dual switch closures. In an application, a decoder, connected to the three sense terminals, converts the sequence of binary codes into three control signals. The three control signals can control a door lock, a trunk lock and an automatic lock function.

Abstract: A keyboard control apparatus for a keyboard having a multicode key, to which are assigned a plurality of codes for characters and symbols, and a control key which is to be pressed at approximately the same time as the multicode key, has a key pressing time delay detection means that detects the times of pressing the multicode key and the control key, a threshold setting means, into which is stored a threshold value with regard to the delay time, a comparison means which compares the threshold value to the delay time between the pressing of the multicode key and the control key, and a key code generation means which, in response to the results of this comparison, validate a prescribed code data of the multicode key in the case in which the delay time is smaller than the threshold value.