An organic light emitting display apparatus that has high (or improved) contrast and/or impact resistance. The organic light emitting display apparatus includes: a substrate; an organic light emitting device on the substrate to display an image; a sealing member on the organic light emitting device; a semitransparent film on a surface of the sealing member facing away from the organic light emitting device to transmit a portion of external light and to reflect another portion of the external light; a passivation film on the semitransparent film to protect the semitransparent film; and a transmissive black layer between the sealing member and the organic light emitting device to increase contrast, wherein the semitransparent film has a refractive index greater than that of the passivation film.

Organic light emitting display apparatus

An analog-to-digital converter for converting an analog input voltage signal to a digital output voltage signal of m upper bits and n lower bits which has a plurality of resistors connected in a series circuit to a voltage source for establishing respective reference voltages, an upper bit encoder having a first input receiving the analog input voltage and second inputs connected to the series circuit at respective intervals defining groups of the resistor therebetween for generating the m upper bits and a switch control signal, each of the groups including a plurality of the resistors, a first lower bit encoder having a first input receiving the analog input voltage signal and second inputs for generating the n lower bits, a second lower bit encoder having a first input receiving the analog input voltage signal and second inputs for generating the n lower bits, a switch circuit associated with each of the groups of the resistors and responsive to the switch control signal for selectively connecting each of the second inputs of the first and second lower bit encoders to respective resistors in the associated group of the resistors, and a circuit for alernately combining the m upper bits with the n lower bits generated by the first and second lower bit encoders and for generating the digital output voltage signal.

Analog-to-digital converter

A compact analog-to-digital converter (ADC) system suitable for high-resolution gamma-ray detectors has been developed around the Burr Brown PCM78P 16-b audio ADC. An associated application-specific integrated circuit (ASIC), handling four ADCs, provides sliding scale circuitry, lower threshold adjustment, channel number identification, and zero suppression. The conversion time is 4.5 mu s, and the differential nonlinearity, for 13-b resolution, is less than +or-0.8%. >

Analog to digital converter

WE 54,364 ABSTRACT OF THE DISCLOSURE Apparatus for measuring current over a wide range generates an eight bit accurate, 16-bit dynamic range digital signal from a current transformer secondary. Two signals proportional to the rectified secondary current, one generated by a large burden resistor and the other by an amplifier with programmable gain and an overrange indication, are applied through a multiplexer to an eight bit analog to digital converter which has three selectable reference voltages. A microprocessor selects the input signal, converter reference voltage, and one of four levels of amplifier gain which provide the greatest resolution for the magnitude of the current being measured, and provides an appropriate scale factor, from 20 to 28, for the eight bit accurate digital signal generated by the analog to digital converter.

Wide dynamic range current measuring apparatus

A stripe geometry is fabricated in a laser-diode structure having a plurality of epitaxial layers, including in tandem an undoped active semiconductor layer (3), a p-doped semiconductor layer (4), a moderately n-doped semiconductor layer (5) and a heavily p + -doped layer (6) by focusing laser radiation on the n-doped semiconductor layer (5). The laser radiation is chosen to have a wavelength which passes through the p + -doped layer (6) without absorption. When the laser radiation is absorbed in the n-doped layer, heat is generated which causes diffusion of p-dopant from the two adjacent layers to convert the exposed region to p-type. As the laser beam is scanned, a stripe having a forward pn junction for laser action is formed.

Heterojunction semiconductor laser fabrication utilizing laser radiation

An analog-to-digital converter includes a first and a second comparator each of which receives an analog input. The first comparator generates a plurality of reference voltages which establish a first continuous range of voltage gaps. The first comparator has a plurality of quantizing outputs, one of which will be at a logical one and the rest of which will be at logical zeros in order to indicate which of the voltage gaps encompasses the analog input voltage. The first comparator also has first and second reference current outputs whose magnitudes are representative of which voltage gap encompasses the analog input voltage and a third reference current output whose magnitude is representative of the voltage gap width. A first encoder receives the quantizing outputs of the first comparator and generates a binary number which represents which of the voltage gaps the analog input voltage is encompassed by and which constitutes the most significant bit group of the binary digital representation of the analog input voltage. The reference current outputs of the first comparator are input to a reference voltage level shifting circuit whose output voltage represents the voltage difference between a first boundary of the voltage gap which encompasses the analog input voltage and the maximum reference voltage value associated with the first comparator. The reference voltage level shifting output voltage is produced concurrently with the action of the first encoder, thereby providing overlapping operations for increased conversion speeds. This shifted reference voltage is provided as an input to a second comparator which compares the analog input with a plurality of internal reference voltages which form a second continuous range of voltage gaps. The second comparator has a plurality of outputs, one corresponding to each of the voltage gaps encompassed by the reference voltages in the second comparator. The second comparator produces a logical one on an output corresponding to the particular voltage gap defined by the shifted reference voltage. A second encoder receives as inputs the outputs of the second comparator and generates a binary output which represents the least significant bit group of the analog input voltage. In combination, the output of the first encoder and the output of the second encoder form a binary digital representation of the analog input voltage, including the most significant bits and the least significant bits thereof.

Serial-parallel analog-to-digital converter using voltage level shifting of a maximum reference voltage

An analog-to-digital converter includes a first comparator which receives an analog input. The first comparator generates a plurality of reference voltages which establish a first continuous range of voltage gaps. The first comparator has a plurality of quantizing outputs, one of which will be at a logical one and the rest of which will be at logical zeros in order to indicate which of the voltage gaps encompasses the analog input voltage. The first comparator also has a reference current output whose magnitude is representative of which voltage gap encompasses the analog input voltage. A first encoder receives the quantizing outputs of the first comparator and generates a binary number which represents which of the voltage gaps the analog input voltage is encompassed by and which constitutes the most significant bit group of the binary digital representation of the analog input voltage. A voltage subtractor circuit receives as inputs the reference current output of the first comparator and the analog input. The voltage subtractor produces an output voltage which represents the voltage difference between a first boundary of the voltage gap which encompasses the analog input voltage and the value of the analog input voltage. The voltage subtractor output voltage is produced concurrently with the action of the first encoder, thereby providing overlapping operations for increased conversion speeds. This voltage is provided as an input to a second comparator which compares the output voltage produced by the voltage subtractor with a plurality of internal reference voltages which form a second continuous range of voltage gaps. The second comparator has a plurality of outputs, one corresponding to each of the voltage gaps encompassed by the reference voltages in the second comparator. The second comparator produces a logical one on an output corresponding to the particular voltage gap which encompasses the difference voltage produced by the voltage subtractor. A second encoder receives as inputs the outputs of the second comparator and generates a binary output which represents the difference voltage produced by the voltage subtractor and which constitutes the least significant bit group of the analog input voltage. In combination, the output of the first encoder and the output of the second encoder form a binary digital representation of the analog input voltage, including the most significant bits and the least significant bits thereof.

Serial-parallel analog-to-digital converter using voltage subtraction

A high-speed voltage subtractor circuit suitable for use in a serial-parallel A/D converter uses differential current switches to select a predetermined reference voltage value as one input to a precision current matching circuit whose other input is an applied analog input signal An output buffer circuit coupled to the current matching circuit produces an output signal equal to the difference between the analog input signal and the reference voltage value

Stephen J. Kreinick

Papers

Serial-parallel analog-to-digital converter using voltage level shifting of a maximum reference voltage

Serial-parallel analog-to-digital converter using voltage subtraction

Voltage subtractor for serial-parallel analog-to-digital converter