Abstract: Compensation needed to be made for reduced light efficiency in aged sub-pixels of an active matrix organic light-emitting diode (OLED) display are determined using a current ratio or a voltage ratio pertaining to an aged sub-pixel relative to un-aged, reference sub-pixels. When the current through the sub-pixels or the voltage across the sub-pixels are measured to determine the age of the sub-pixels, correction is made to the measured current or voltage to account for variations in the ambient temperature in which the OLED display is placed.

Abstract: A touch screen includes a plurality of single-layer ITO bars having a substantially rectangular shape and arranged in parallel to each other in order to detect touches on the touch screen. The location of a touch on the touch screen in the direction along an ITO bar is determined by applying a signal on one end of the ITO bar and measuring the change in the amplitude and the delay of the signal on the opposite end of the ITO bar. Such application and measurement of the signal can be repeated with the application of the signal occurring on the opposite end of the ITO bar and the measurement of the signal occurring on said one end of the ITO bar, in order to enhance the accuracy of the measurement.

Abstract: A key is determined to be the user-selected key of a touch sensitive input device if the touch on the key is determined to be valid continuously for longer than a first predetermined period of time. Another key may be determined to the user-selected key, replacing the previously determined user-selected key, if the touch on another key is valid continuously for a second predetermined period of time that may be longer than the first predetermined period of time.

Abstract: A new Class L amplifier which dynamically switches between multiple pairs of power rails, and has the ability to select the most advantageous combination of rails for the minimization of power dissipation in the amplifier. A bridged amplifier system using two Class L amplifiers to drive a load.

Abstract: A new Class L amplifier which dynamically switches between multiple pairs of power rails, and has the ability to select the most advantageous combination of rails for the minimization of power dissipation in the amplifier. In one embodiment, a bridged amplifier system includes two Class L amplifiers to drive a load.

Abstract: Disclosed are a device and a method for driving a display element that adjusts a backlight luminescence to be suitable for a mean luminescence of an image data for each frame, analyzes the mean, maximum and minimum luminescence of an image to be displayed to reduce power consumption due to unnecessary backlight luminescence, and then adjusts the backlight luminescence in accordance with the analyzed result. The device for driving a display element includes a buffer memory, a histogram analyzer, a main memory, a maximum luminescence determining and mapping unit and a digital-to-analog converter (DAC). When an image data to be displayed for each frame is inputted to the buffer memory, the histogram analyzer analyzes the image data for each frame to calculate a mean luminescence, a maximum/minimum luminescence and a histogram for each of the R, G and B colors, and then outputs the analyzed image data for each frame to the maximum luminescence determining and mapping unit.

Abstract: An improved Class G type amplifier is provided which switches between multiple power rails depending upon the instantaneous amplitude of the input signal versus the power rails without excessive distortion. The low voltage (inner) amplifier includes a plurality of parallel amplifier devices, and the high voltage (outer) amplifier includes a plurality of parallel amplifier devices. A plurality of switches each couples the input signal to either a respective one of the inner amplifier devices or a respective one of the outer amplifier devices. The switches are activated sequentially, such that the switching from inner amplifier devices to outer amplifier devices or vice versa is staggered over time. This avoids having a single, large glitch in the output and spreads multiple smaller glitches over enough time so that some of the radiated glitch energy can fall within frequencies where amplifier feedback circuitry can eliminate its noise. The switches are sequentially activated by a series of delay elements.

Abstract: Compensation needed to be made for reduced light efficiency in aged sub-pixels of an active matrix organic light-emitting diode (OLED) display are determined using a current ratio or a voltage ratio pertaining to an aged sub-pixel relative to un-aged, reference sub-pixels. When the current through the sub-pixels or the voltage across the sub-pixels are measured to determine the age of the sub-pixels, correction is made to the measured current or voltage to account for variations in the ambient temperature in which the OLED display is placed.

Abstract: Compensation needed to be made for reduced light efficiency in aged sub-pixels of an active matrix organic light-emitting diode (OLED) display are determined using a current ratio or a voltage ratio pertaining to an aged sub-pixel relative to un-aged, reference sub-pixels.

Abstract: An improved Class G type amplifier which switches between multiple power rails depending upon the instantaneous amplitude of the input signal versus the power rails. The low voltage (inner) amplifier includes a plurality of parallel amplifier devices, and the high voltage (outer) amplifier includes a plurality of parallel amplifier devices. A plurality of switches each couples the input signal to either a respective one of the inner amplifier devices or a respective one of the outer amplifier devices. The switches are activated sequentially, such that the switching from inner to outer amplifier devices or vice versa is staggered over some period of time. This avoids having a single, large glitch in the output, and spreads multiple smaller glitches over enough time that some of the glitch energy can fall within the frequency range where the amplifier's feedback circuitry can eliminate its noise. The switches are sequentially activated by a series of delay elements.

Abstract: A voltage reference generation circuit having switch pairs coupled to systematically commutate a flying capacitor among adjacent pairs of voltage rail outputs. The circuit requires only a single flying capacitor, N+1 switch pairs, and N storage capacitors, to generate N intermediate voltage references between VDD and GND. A signal generator produces N+1 non-overlapping switch enable signals to systematically enable the switch pairs and commutate the single flying capacitor between the rail pairs. The flying capacitor remains charged to VDD/(N+1). The N storage capacitors hold their respective reference outputs at VDD*N/(N+1), VDD*(N?1)/(N+1), VDD*(N?2)/(N+1), and so forth.

Abstract: An organic light-emitting diode display driver adjusts the display scan period of the current driving the organic light-emitting diodes of a selected row based upon the sum of the display data corresponding to the selected row, thereby removing crosstalk in the OLED display panel. The driver includes an adder for adding the display data corresponding to the selected row and a scan period look-up table storing display scan period values. The scan period look-up table is configured such that it outputs display scan period values substantially proportional or inversely proportional to the sum of the display data to remove bright crosstalk or dark crosstalk, respectively, in the OLED display panel.

Abstract: An amplifier system having one or more signal paths. Each path includes a phase amplifier and a Class G Type amplifier. The phase amplifier receives an input signal bearing phase information. The Class G Type amplifier receives an envelope signal bearing amplitude information. The output of the Class G Type amplifier is coupled to provide the VCC reference for the phase amplifier. Thus, the output signal of the phase amplifier bears both phase and amplitude information. High frequency performance and high efficiency are obtained.

Abstract: An amplifier system having one or more signal paths. Each path includes a linear amplifier and a Class G Type amplifier. The linear amplifier receives an input signal bearing phase and amplitude information. The Class G Type amplifier receives an envelope signal which tracks the anticipated output signal, plus a DC offset. The output of the Class G Type amplifier is coupled to provide the VCC reference for the linear amplifier. High frequency performance and high efficiency are obtained.

Abstract: An audio amplifier system having improved power efficiency by wasting less power in its bias voltage circuit. An amplifier provides a voice signal to a first (+) input of a loudspeaker and a high efficiency converter provides a bias voltage to a second (?) input of the loudspeaker. In multi-loudspeaker systems, a single high efficiency converter can bias all the loudspeakers at a common node. The high efficiency converter can be a charge pump or a buck converter or the like, and has greater than 90% efficiency.

Abstract: An improved Class G type amplifier which switches between multiple power rails depending upon the instantaneous amplitude of the input signal versus the power rails. The low voltage (inner) amplifier includes a plurality of parallel amplifier devices, and the high voltage (outer) amplifier includes a plurality of parallel amplifier devices. A plurality of switches each couples the input signal to either a respective one of the inner amplifier devices or a respective one of the outer amplifier devices. The switches are activated sequentially, such that the switching from inner to outer amplifier devices or vice versa is staggered over some period of time. This avoids having a single, large glitch in the output, and spreads multiple smaller glitches over enough time that some of the glitch energy can fall within the frequency range where the amplifier's feedback circuitry can eliminate its noise. The switches are sequentially activated by a series of delay elements.

Abstract: A phase-slipping phase-locked loop which generates an output signal whose frequency is a non-integer multiple of a reference frequency. The PLL has a first input for receiving a first binary value i which specifies an integer portion of the frequency multiplier, and a second input for receiving a second binary value f which specifies a fractional portion of the frequency multiplier. A multi-phase VCO has a plurality v of outputs on equal phase shifted spacing. The phase slipping is applied every i cycles, and the second binary value f specifies a phase slip stride, such that the frequency multiplier equals i+f/v.

Abstract: An RF power amplification system having a power amplifier, a matching network, and an antenna power controller which compares a voltage at the matching network output to a voltage at the matching network input and uses a result of that comparison to manipulate the power amplifier and/or the matching network, to control the power applied to the antenna. In one embodiment, the power controller tristates one or more of a plurality of parallel power amplifier devices in the amplifier, to control the antenna power. In another embodiment, the power controller manipulates a plurality of parallel resistors or other impedances in the power amplifier, switching some impedances in and some impedances out, to maximize the power coupling to the antenna or to operate the amplifier device in a maximally efficient operating range.

Abstract: A new Class L amplifier which dynamically switches between multiple pairs of power rails, and has the ability to select the most advantageous combination of rails for the minimization of power dissipation in the amplifier. A bridged amplifier system using two Class L amplifiers to drive a load.

Abstract: An audio amplifier such as for driving headphones. The amplifier includes multiple amplifier devices coupled in parallel. Both a bias generator and a volume control are responsive to a user setting. Under low output signal conditions, one or more of the amplifier devices are disabled in response to the user setting. Disabled amplifier devices do not consume output bias current. Thus the audio amplifier has reduced power consumption, and the system has longer battery life.