Abstract: There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

Abstract: There is provided an optical encoder including a phase shifter circuit and a multiple hysteresis comparators. The phase shifter circuit receives four input signals, and outputs multiple phase shifted signals based on the four input signals. Each of the multiple hysteresis comparators uses a changeable operation hysteresis level to compare a couple of phase shifted signals among the multiple phase shifted signals, wherein the changeable operation hysteresis level is determined corresponding to a signal frequency of the four input signals.

Abstract: There is provided an optical encoder including a phase shifter circuit and a multiple hysteresis comparators. The phase shifter circuit receives four input signals, and outputs multiple phase shifted signals based on the four input signals. Each of the multiple hysteresis comparators uses a changeable operation hysteresis level to compare a couple of phase shifted signals among the multiple phase shifted signals, wherein the changeable operation hysteresis level is determined corresponding to a signal frequency of the four input signals.

Abstract: There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

Abstract: There is provided an optical encoder including an encoding medium and a substrate. The encoding medium has a relative movement with respect to the substrate in a predetermined direction. The substrate includes an index photodiode and two control photodiodes. The index photodiode is arranged between the two control photodiodes along the predetermined direction. The output signals of the two control photodiodes are for controlling ON/OFF of gain regulation on an output signal of the index photodiode so as to turn on the gain regulation within an interval during which the index photodiode does not generate an index pulse but to turn off the gain regulation within an interval during which the index photodiode generates the index pulse.

Abstract: There is provided an optical encoder including an encoding medium and a substrate. The encoding medium has a relative movement with respect to the substrate in a predetermined direction. The substrate includes an index photodiode and two control photodiodes. The index photodiode is arranged between the two control photodiodes along the predetermined direction. The output signals of the two control photodiodes are for controlling ON/OFF of gain regulation on an output signal of the index photodiode so as to turn on the gain regulation within an interval during which the index photodiode does not generate an index pulse but to turn off the gain regulation within an interval during which the index photodiode generates the index pulse.

Abstract: There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

Abstract: There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

Abstract: There is provided an optical encoder including a phase shifter circuit and a multiple hysteresis comparators. The phase shifter circuit receives four input signals, and outputs multiple phase shifted signals based on the four input signals. Each of the multiple hysteresis comparators uses a changeable operation hysteresis level to compare a couple of phase shifted signals among the multiple phase shifted signals, wherein the changeable operation hysteresis level is determined corresponding to a signal frequency of the four input signals.

Abstract: There is provided an optical encoder including an encoding medium and a substrate. The encoding medium has a relative movement with respect to the substrate in a predetermined direction. The substrate includes an index photodiode and two control photodiodes. The index photodiode is arranged between the two control photodiodes along the predetermined direction. The output signals of the two control photodiodes are for controlling ON/OFF of gain regulation on an output signal of the index photodiode so as to turn on the gain regulation within an interval during which the index photodiode does not generate an index pulse but to turn off the gain regulation within an interval during which the index photodiode generates the index pulse.

Abstract: There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

Abstract: There is provided a phase shifter circuit of an optical encoder that receives four signals generated from photodiodes. The phase shifter circuit includes four resistor strings each coupled to two of the four signals having a 90-degrees phase pitch. By taping out different numbers of signals at different tape-out nodes of each of the four resistor strings, the phase shifter circuit is adapted to output signals for different interpolation factors without changing the mask set.

Abstract: Disclosed are various embodiments of circuitry and methods to compensate for variations in hysteresis associated with the comparators of an interpolation circuit in a single track optical encoder. Such variations in hysteresis may be minimized or eliminated by providing appropriately configured resistor ladder circuits to condition the inputs to the comparators, or by programming or trimming resistors in positive feedback loops of the comparators. The single track optical encoder configurations disclosed herein permit very high resolution reflective optical encoders in small packages to be provided. Methods of making and using such optical encoders are also disclosed.

Abstract: Disclosed are various embodiments of a single track reflective optical encoder featuring current amplifiers disposed in the signal generating circuit thereof. Voltage amplifiers and their associated feedback resistors are eliminated in the various embodiments disclosed herein, resulting in decreased die size and improved encoder signal accuracy and performance, especially at high speeds The single track optical encoder configurations disclosed herein permit very high resolution reflective optical encoders in small packages to be provided. Methods of making and using such optical encoders are also disclosed.

Abstract: Disclosed are various embodiments of a reflective optical encoder having at least three channels—two data channels and one index channel—disposed along a common axis or single track. The single track configuration disclosed herein permits very high resolution reflective optical encoders in small packages to be provided. In addition, the single track configuration reduces problems with misalignment between code scales and light detectors, permits relatively simple electronic circuitry to be used to process outputs, and reduces manufacturing, assembly, integrated circuit and encoder costs. Methods of making and using such optical encoders are also disclosed.

Abstract: Disclosed are various embodiments of circuitry and methods to compensate for variations in hysteresis associated with the comparators of an interpolation circuit in a single track optical encoder. Such variations in hysteresis may be minimized or eliminated by providing appropriately configured resistor ladder circuits to condition the inputs to the comparators, or by programming or trimming resistors in positive feedback loops of the comparators. The single track optical encoder configurations disclosed herein permit very high resolution reflective optical encoders in small packages to be provided. Methods of making and using such optical encoders are 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: Disclosed are various embodiments of a single track reflective optical encoder featuring current amplifiers disposed in the signal generating circuit thereof. Voltage amplifiers and their associated feedback resistors are eliminated in the various embodiments disclosed herein, resulting in decreased die size and improved encoder signal accuracy and performance, especially at high speeds The single track optical encoder configurations disclosed herein permit very high resolution reflective optical encoders in small packages to be provided. Methods of making and using such optical encoders are also disclosed.

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 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.