Abstract: A digital tuning controller is provided which utilizes the storage of codes relating to the location and bandwidth of unused or illegal frequency bands to control a frequency acquisition operation with minimum circuitry.A two digit keyboard entry corresponding to a selected channel number is stored. First counter means indicates a current channel location. Second counter means counts regularly spaced frequency markers produced as the band is scanned to increment the first counter. A comparator signals coincidence between the content of the first counter and the keyboard entry. A third counter counts the frequency markers for comparison with the current output state of a read only memory (ROM) having stored codes corresponding to the location and bandwidth of the unused frequency bands. Upon coincidence, the third counter is reset, the second counter is inhibited and the next succeeding location of the ROM is addressed to provide an output state indicating the bandwidth of the skip band.

Abstract: Disclosed is an improved electrochromic optical display cell having a memory, long life, good contrast independent of viewing angle, reversibility, low switching voltage, and a low mean power consumption wherein a soluble colorless dye is selectively and reversibly reduced at a display electrode to form an insoluble, insulating film that markedly absorbs visible light. The electrochromic display cell includes an electrode through which a potential is applied across the cell to regenerate the coulombic capacity of the counter electrode. The counter electrode is regenerated by reverse electrolysis without deleteriously affecting cell operation. In a preferred embodiment, the regeneration electrode is palladium.In another embodiment, the display electrode normally present in the display cell is utilized as the regeneration electrode. The potential applied across the cell for regeneration is larger than the normal potential applied to erase the cell.

Abstract: An automatic oscillator frequency control is provided for operations such as employed in channel selection in radio and television receiver systems. A code is stored representative of a selected frequency band within which a selected channel is located. The frequency of an oscillator is varied monotonically from a reference frequency at one extremity of a selected frequency range successively to traverse a plurality of such frequency bands. A frequency marker is generated at the margin of each band and the markers are counted. The number of counted markers is compared with the stored code to generate a control state. In response to the control state, a pattern control causes it to dither between limits of the selected band until a signal is encountered at the selected frequency within the selected band. At that point, the oscillator is locked to the frequency of the received signal.

Abstract: Disclosed is a multichannel drainage system for separately draining the centrifugally broadcast residue of different liquids sequentially dispensed on the top surface of a semiconductor wafer spun on a spindle at a work station. The multichannel drainage system includes a cup assembly mounted on a cup plate which is raised and lowered by elevator apparatus. The cup assembly has a lower drainage cup forming an annular channel and a first outlet communicating with the channel. An upper drainage cup, stacked atop the lower cup, forms a second annular channel communicating with a second outlet. The elevator apparatus raises or lowers the cup plate under the action of a cam. The cam has a three-stage profile, with each stage corresponding to a stationary position of the cup assembly relative the wafer. In the home position for loading and unloading the wafer, the cup assembly is below the wafer.

Abstract: Disclosed is an improved electrochromic optical display cell having a memory, long life, good contrast independent of viewing angle, reversibility, low switching voltage, and a low mean power consumption wherein a soluble colorless dye is selectively and reversibly reduced at a display electrode to form an insoluble, insulating film that markedly absorbs visible light. The electrochromic display cell includes a display electrode and a non-polarizable counter electrode which simultaneously maintains a threshold potential while providing charge transfer to a electrolytically reduce the dye during a write cycle or oxidize the dye during an erase cycle. The preferred counter electrode forms a lead/lead phosphate half cell which has a substantially stable electrochemical potential over the area of operation, reversibly undergoes oxidation-reduction and will not substantially irreversibly reduce the dye. Further, the lead counter electrode can be electrochemically restored by reverse electrolysis.

Abstract: A digital scanning system for a digital to analog converter. The scanning system includes an information counter for storing a plurality of digital bits I1, I2, I3....IN, with bit I1 being the most significant bit and bit IN being the least significant bit. Logic gates are connected between the information and interconnected shift registers. A clock applies clock frequency signals to the shift registers such that the digital bits are output in the periodic sequence I1, I2, I1, I3, I1, I2, I1, I4, I1, I2, I1, I3, I1...I1, I2, I1, IN. The periodic sequence of digital bits is applied to an integrator which outputs a voltage level representative of the periodic sequence.

Abstract: An FM tuner for feeding an IF section of a receiver circuit includes an antenna signal input circuit with broad band response to signals in a selected FM broadcast band. A mixer is connected to receive the signal from the input circuit and a variable local oscillator is connected to the mixer operating for high side injection to produce an IF signal centered within an RF band of minimal signal content and to produce an image displaced outside the response of the input circuit. An SWD filter connected to the output of the mixer has narrow band response at the IF frequency.

Abstract: Digitally controlled tuning by storing a digital code representative of the frequency of a selected channel and generating successive digital counts, each proportional to the number of cycles of an oscillator signal in each of a plurality of successive uniform sample intervals. The digital code is then compared with a digital count to generate a first output when equal, a second output when the code exceeds the count, and a third output when the count exceeds the code. The frequency of the oscillator is varied in response to one of the second and third outputs to increase or decrease the frequency, respectively, and to permit the frequency of the oscillator to lock in response to the first output signal.

Abstract: A semiconductor wafer baking and handling system includes a pair of wheel assemblies each comprising a pair of spaced apart plates having opposed, aligned slots formed therein for receiving and supporting semiconductor wafers. A wafer transporting air track includes portions extending between the plates of both of the wheel assemblies. The wheel assemblies are rotated about axes lying substantially in the plane of and extending perpendicularly to the path of wafer travel along the air track to sequentially position the slots to receive semiconductor wafers, to rotate the received semiconductor wafers through an arc of 180.degree., and to subsequently sequentially position the slots to effect removal of the semiconductor wafers. One of the wheel assemblies is mounted in a housing which also encloses a heater, a fan, and baffles for directing gas from the fan across the heater and across the wafers to effect baking of the wafers.

Abstract: An SWD structure is employed in an FM receiver for signal demodulation and band limiting. An FM signal is applied to the input of an SWD patterned for bandwidth limitation. Two SWD output channels characterized by predetermined differential delays of the modulated input signal are amplitude limited and mixed to produce an audio modulation component.