Abstract: A circuit is disclosed for driving an OLED in a graphics display. The circuit employs a current source operating in a switched mode. The output of the current source is connected to a terminal of the OLED. The current source is responsive to a combination of a selectively set cyclical voltage signal and a cyclical variable amplitude voltage signal. The current source, when switched on, is designed and optimized to supply the OLED with the amount of current necessary for the OLED to achieve maximum luminance. When switched off, the current source blocks the supply of current to the OLED, providing a uniform black level for an OLED display. The apparent luminance of the OLED is controlled by modulating the pulse width of the current supplied to the OLED, thus varying the length of time during which current is supplied to the OLED.

Abstract: A novel photographic cropping method and device, which may eliminate the need to cut or mark photos being cropped, is disclosed.

Abstract: Conventional skipping ropes have a generally elongate handle swivellably mounted on each end of the rope which is held by the user between the fingers and palms. In accordance with the invention, the handle is shaped like a “T” with the vertical stroke of the T (3) swivellably connected to the rope (1). The handle may be held with the crosspiece of the T (4) between fingers and palm and with the vertical extending between two fingers. This gives a more comfortable and effective skipping position.

Abstract: In order to set the output optical power of a laser diode precisely and under digital control without expensive digital to analog conversion devices, a digital controller provides a sequence of pulses. A capacitor is charged by these pulses to produce a control voltage which controls the current through the laser diode via an operational amplifier driver stage. The output power obtained from the laser as detected by a photodetector, which is optically coupled to the laser and may be packaged therewith, is monitored by the computer so as to determine the rate at which laser power changes and indirectly at the rate at which the capacitor charges. This rate may vary depending upon environmental conditions and manufacturing tolerances. Based upon the charging rate, a pulse is generated and used to either provide additional charge or to charge the capacitor to the voltage corresponding to the desired optical power output.

Abstract: A unitary hand-held bar code scanner and reader produces an elliptical beam, oriented with its major axis along the direction of the bars, utilizing optics employing far field diffraction effects to shape the beam and maintain its elliptical aspect (length to width ratio) constant over a distance in front of the scanner were bar codes may be located. The optics eliminates parallax even though the photodetector and light source (preferably a laser diode) are located offset from each other on a board on which the optics are mounted. A housing assembly has channels which mount the board therein without shock absorbing devices. A digital microcomputer controller and peripheral devices regulate the optical power output from the laser diode and prevents catastrophic failure, if the electrical current through the laser diode exceeds safe limits.

Abstract: A system especially suited for powering up and down electronic equipment operated to a power conservation mode, which conserves more power than other power conservation efforts. The system is operated by hitting any key of a keyboard which provides data entry signals via a plurality of data lines. An embodiment disclosed provides a flip-flop having power on and power off outputs and also inputs which change the flip-flop between set and reset states. A first isolation switch connects at least one of the plurality of keyboard data lines to the flip-flop for conditioning the flip-flop into the one of its set and reset states which provides power on output when serial data is provided, as when any key of the keyboard is pressed.

Abstract: A laser drive and control system which provides protection for a laser diode by preventing excess current from a power source, that normally supplies power to the laser diode, from destroying the laser diode when the voltage supplied by the power source to the laser diode decreases below a certain voltage which causes excess current. The system is implemented in CMOS circuitry for miniaturization into an integrated circuit chip.

Abstract: A bar code scanner includes a separate transmitter and receiver, each being able to ultrasonically transmit and receive data, respectively. The receiver transmits an acknowledgement signal when a protocol is received, and sends the acknowledgement signal to the transmitter which, unless it receives the acknowledgement signal, will retransmit the protocol a predetermined number of times. The transmitter includes a receiver which monitors an ultrasonic frequency band for a time period in which transmission by the transmitter is not allowed. The time period corresponds to a time when another ultrasonic signal in the ultrasonic frequency band is detected by the receiver of the transmitter. Transmission by the transmitter is allowed as soon as the another ultrasonic signal is no longer detected by the receiver of the transmitter.

Abstract: An amplifier circuit provides wide bandwidth low noise performance by minimizing the effect of a pole created by the feedback resistor and the capacitance of the input device, such as a photodiode. This is accomplished by shifting the dominant pole to higher frequencies in the amplifier disclosed. A first amplifier stage receives a signal from an input device, such as the photodiode, and feedback from a second amplifier stage. The first amplifier stage is connected to the second amplifier stage such that a lower gain stage is employed to eliminate the phase shift which occurs if the amplifier alone is used in open loop form. The output of the low gain stage is provided to a second amplifier stage with associated gain setting components such that the dominant pole of the overall amplifier is shifted to a higher frequency, typically two decades higher than available from the single stage open loop amplifier.

Abstract: A bar code hand held scanning terminal which combines a data input device, a display and a scanning engine in a single portable unit. This unit is compact and may be employed in, for example, a scanning terminal which is attached to the back of a hand of an operator. Alternatively, the unit may be employed in a gun-type hand held scanning terminal. The combination has a display which is pivotally connected to the hand held scanning terminal such that the display may be in an open position or in a closed position. A light sensor is used to detect the opening or closing of the display portion of the hand held scanning terminal and maybe used to selectively deactivate the scanning beam when the display is open. The scanning device may be used to read bar code labels for inventory or warehousing, in medical prescription distribution, etc.

Abstract: A successive approximation A/D having dual comparators for allowing a larger range of analog input signals to be converted into digital form. One comparator is an N-channel device, and the other comparator is a P-channel device. The A/D switches to either the N-channel device or the P-channel device based upon whether the first two comparisons the determine the most-significant bit and the next-most significant bit are a "11", in which the N-channel device is selected, or anything else, in which the P-channel device is selected. Switching circuitry is included to output the proper comparator based on these two comparisons.Control circuitry is also provided to allow for successive conversions using only a single address read.

Abstract: An improved miniature scanning module for scanning and reading data fields having images or symbols such as bar codes, adapted to be included in a scanning application such as a portable transaction terminal. The scan engine of the module has an oscillator apparatus in which at least one side of a vertical coil cuts lines of magnetic force from an independent fixed magnet assembly and has a rotor and a stator which are molded interconnect devices in which electrical circuits are formed by surface plating or printing during multiple-shot molding of the parts. The rotor is supported by a plurality of metal alloy flexures depending from the stator, which flexures both mechanically support the rotor and transmit electrical power and signals between control circuitry on one or more printed circuit boards on the stator and electrical elements on the rotor. A semiconductor laser diode mounted on the rotor scans in one dimension when the rotor oscillates.

Abstract: A system for bar code reading and scanning is provided having automatic gain control for accurate reading of bar codes over a range of distance. An amplifier within the system provides a plurality of selectable amplification gain levels for increasing the size of the signal received by a digitizing element. A processor is programmed to select the gain level. The system has a light source, preferably a laser diode, and a laser diode circuit, which provides accurate setting by the processor of the laser optical power output. The laser diode is calibrated according to each selected gain level of the amplifier such that the system can scan within a desired range of distances from the system to a bar code. The system successively scans a bar code, with each scan being at a different amplification level. In the alternative, a signal size detector provides a signal representative of the size of the signal to the digitizer.

Abstract: A system for use in a bar code processing system using a combination of a first derivative signal and a second derivative signal to determine the bar edge. The predominant signal in determining the edge is the second derivative signal. A zero-cross of the second derivative signal occurs at the bar edge. The first derivative signal is used to qualify the point in time in the second derivative signal for which a zero-cross is examined the system is particularly suited for near filled operation.

Abstract: A resolution enhancer circuit provides an increased resolution capability for an A/D converter. The resolution enhancer circuit receives as input an analog input signal having a range greater than the effective range of the A/D, and prescales the input signal to a range that is within the common mode range of op amps used within the resolution enhancer circuit. The input signal can also have a range much less than the effective range of the A/D, and then it would be increased by the prescaler to be within an operable range of the A/D. The prescaled signal is provided to a sampling circuit, which samples the prescaled signal at times determined to be near-saturation conditions of the A/D. A magnified difference between the prescaled signal and the sampled signal, biased to the sampled signal, is then input to the A/D, which determines a number of A/D counts based on that value.

Abstract: An optical scanner unit has a window which transmits light from inside the scanner to a target, for example, a bar code, and receives light from a target into the scanner. The window is tilted at Brewster's angle to permit light from inside the scanner to exit the scanner without "exit reflection" of light off the interior of the window. The window also permits light returned from the scanned target to enter the scanner and be sensed by a photodetector therein. The same window may be used for light transmitted to the photodetector and from the light source. The window is disposed at Brewster's angle relative to the scanning beam at the center of scan, and is close to Brewster's angle over the entire scan.