Abstract: Disclosed are various embodiments of interpolation circuits for use in conjunction with motion encoders. The analog output signals provided by incremental or absolute motion encoders are provided to an interpolation circuit, which is capable of providing high interpolation factor output signals having high timing accuracy. Problems with noise spikes common to zero-hysteresis comparators typically employed in interpolation circuits are eliminated, as are problems with time delays differing between comparators that do feature hysteresis. The disclosed interpolation circuits may be implemented using CMOS processes without undue effort.

Abstract: Disclosed are various embodiments of interpolation circuits for use in conjunction with optical encoders. The analog output signals provided by incremental or absolute motion encoders are provided to an interpolation circuit, which is capable of providing high interpolation factor output signals having high timing accuracy. The disclosed interpolation circuits may be implemented using CMOS or BiCMOS processes without undue effort.

Abstract: A method for determining the light intensity of a light signal in each of a plurality of spectral bands is disclosed and a method for fabricating a photodetector is also disclosed.

Abstract: A method for determining the light intensity of a light signal in each of a plurality of spectral bands is disclosed and a method for fabricating a photodetector is also disclosed.

Abstract: Disclosed are various embodiments of a single track reflective optical encoder featuring increased spatial resolution, reduced cross-talk between adjoining photodiodes, and increased amplitude output signals from individual photodiodes. With respect to prior art single track optical encoders, some photodiodes are removed from a photodiode array, while nevertheless maintaining appropriate phase relationships between pairs of A and A\, and B and B\, photodiodes. Such a configuration of photodiodes results in increased inter-photodiode spacing, and thereby permits spatial resolution to be increased while boosting current outputs from individual photodiodes. The single track optical encoder configurations disclosed herein permit very high resolution reflective optical encoders in small packages to be provided.

Abstract: According to one embodiment, there is provided a device and method for correcting code wheel misalignment which employs upper and lower code wheel misalignment photodetectors positioned above and below at least first and second motion detection photodetectors. According to other embodiments, there are provided a device and method for automatically setting the gain of an output circuit in an optical encoder. Still further embodiments of optical encoders combine the code wheel misalignment and automatic gain control features of the invention.

Abstract: Disclosed are various embodiments of interpolation circuits for use in conjunction with motion encoders. The analog output signals provided by incremental or absolute motion encoders are provided to an interpolation circuit, which is capable of providing high interpolation factor output signals having high timing accuracy. Problems with noise spikes common to zero-hysteresis comparators typically employed in interpolation circuits are eliminated, as are problems with time delays differing between comparators that do feature hysteresis. The disclosed interpolation circuits may be implemented using CMOS processes without undue effort.

Abstract: Disclosed are various embodiments of interpolation circuits for use in conjunction with optical encoders. The analog output signals provided by incremental or absolute motion encoders are provided to an interpolation circuit, which is capable of providing high interpolation factor output signals having high timing accuracy. The disclosed interpolation circuits may be implemented using CMOS or BiCMOS processes without undue effort.

Abstract: Disclosed are various embodiments of pulse generation and automatic gain control (“AGC”) circuits and corresponding methods that are especially well suited for use in motion encoding systems. Analog output signals provided by a motion encoder serve as inputs to the pulse generation circuit, where peaks, valleys and/or crosspoints corresponding to such analog signals are first detected and then employed to generate output pulses corresponding thereto. These output pulses are next provided to an AGC circuit as self-generated clock signals which control the time windows over which the analog signals of the motion encoder are sampled and processed by the AGC circuit so as to adjust the gains applied to such analog signals.

Abstract: According to one embodiment, there is provided an optical encoder having a photodetector array comprising motion detection photodetectors and at least one reference photodetector vertically offset from the motion detection photodetectors. The output signal generated by the at least one reference photodetectors is employed to correct undesired variations in the amplitudes of the output signals generated by the motion detection photodetectors. Such variations typically arise from various mechanical and optical misalignments in the optical encoder, and are compensated for by using the reference output signal to add to or subtract from, as required, the amplitudes of motion detection output signals.

Abstract: According to one embodiment, there is provided a device and method for correcting code wheel misalignment which employs upper and lower code wheel misalignment photodetectors positioned above and below at least first and second motion detection photodetectors. According to other embodiments, there are provided a device and method for automatically setting the gain of an output circuit in an optical encoder. Still further embodiments of optical encoders combine the code wheel misalignment and automatic gain control features of the invention.

Abstract: A photodetector and method for making the same is disclosed. The photodetector includes a substrate having first, second, and third photodiodes and first and second pigment filter layers. The first, second, and third photodiodes generate first, second, and third photodiode output signals, respectively, each photodiode output signal being indicative of a light intensity incident on that photodiode and a dark current that is independent of the light intensity. The first and second pigment filter layers overlie the first and second photodiodes while a layer having both the first and second pigment filter layers overlie the third photodiode. An output circuit combines the first and third photodiode output signals to provide a first corrected output signal and combines the second and third photodiode output signals to provide a second corrected output signal.

Abstract: Disclosed are various embodiments of temperature-compensated relaxation oscillator circuits that may be fabricated using conventional CMOS manufacturing techniques. The relaxation oscillator circuits described herein exhibit superior low temperature coefficient performance characteristics, and do not require the use of expensive off-chip high precision resistors to effect temperature compensation. Positive and negative temperature coefficient resistors arranged in a resistor array offset one another to provide temperature compensation in the relaxation oscillator circuit.

Abstract: According to one embodiment, there is provided a device and method for correcting code wheel misalignment which employs upper and lower code wheel misalignment photodetectors positioned above and below at least first and second motion detection photodetectors. According to other embodiments, there are provided a device and method for automatically setting the gain of an output circuit in an optical encoder. Still further embodiments of optical encoders combine the code wheel misalignment and automatic gain control features of the invention.

Abstract: According to one embodiment, there is provided an optical encoder having a photodetector array comprising motion detection photodetectors and at least one reference photodetector vertically offset from the motion detection photodetectors. The output signal generated by the at least one reference photodetectors is employed to correct undesired variations in the amplitudes of the output signals generated by the motion detection photodetectors. Such variations typically arise from various mechanical and optical misalignments in the optical encoder, and are compensated for by using the reference output signal to add to or subtract from, as required, the amplitudes of motion detection output signals.

Abstract: A device and method for producing an enhanced color image of a scene of interest captures a grayscale image of the scene of interest using a flash of infrared light and a color image of the scene of interest without using any flash of infrared light. The grayscale information from the grayscale image and the visible color information from the color image are combined to produce the enhanced color image.

Abstract: An optical receiver having a photodetector, a variable gain amplifier, and a gain control circuit is disclosed. The photodetector generates a photodetector output signal related to an intensity of light received by the photodetector, the photodetector output signal being characterized by a peak-to-peak signal value. The variable gain amplifier amplifies the photodetector output signal to generate a receiver output signal that is coupled to an external device, the variable gain amplifier having a gain that is determined by a gain control signal. The gain control circuit receives the receiver output signal and generates the gain control signal therefrom. The gain control signal causes the gain of the variable gain amplifier to decrease as a function of the peak-to-peak signal value to reduce changes in the output signal amplitude as a function of the input light signal amplitude.

Abstract: An electronic flash, imaging device and method for producing flashes of light uses a diffractive optical element to produce a flash of light having a rectangular radiation pattern. The diffractive optical element is configured to diffract light emitted from a light source such that the radiation pattern of the light emitted from the diffractive optical element is rectangular to produce the rectangular flash of light.

Abstract: A camera flash is disclosed for producing a warm light having a desired color temperature. In one embodiment, the flash has a xenon flash component producing a light with a spectrum having a color temperature at a higher Kelvin rating than the warm light, and a light emitting diode flash component producing a light with a spectrum having a color temperature at a lower Kelvin rating than the warm light. The color temperature of the light of the xenon flash component and the color temperature of the light of the light emitting diode flash component together produce the warm light having the desired color temperature.

Abstract: A light sensor that generates a first output signal indicative of an intensity of light received from a predetermined direction in a first band of wavelengths is disclosed. The light sensor includes a substrate having first and second photodetectors, a first filter layer, and a controller. The photodetectors are sensitive to light in the infrared portion of the optical spectrum as well as to light in the first band of wavelengths, and generate first and second photodetector signals. The first filter layer transmits light in the first band of wavelengths and light in the infrared portion of the optical spectrum while blocking light in a portion of the visible spectrum outside of the first band of wavelengths, without altering light received by the first photodetector. The controller processes the first and second photodetector signals to produce the first output signal that is corrected for infrared in the input light.