There is provided an optical encoder including a phase shifter circuit, two multiplexers, two digital circuits and four comparators. The phase shifter circuit receives signals from an amplifier and outputs multiple phase shifted signals. Each of the two multiplexers receives a half of the multiple phase shifted signals and outputs two pairs of phase shifted signals, each pair having 180 degrees phase difference, respectively to two comparators connected thereto. Each of the two digital circuits controls the corresponding multiplexer to select the two pairs of phase shifted signals from the half of the multiple phase shifted signals.

Provided is an encoder apparatus that is free from battery maintenance or has low frequency of battery maintenance. The encoder apparatus includes: a position detection system including: a scale; a light emitter that irradiates the scale with light; a light detector that changes a relative position thereof with the scale in response to movement of a mover; and a detector that detects position information on the mover based on a detection result of the light detector. The encoder apparatus also includes an electric signal generator that generates an electric signal in response to the movement of the mover; and a light emission adjuster that adjusts emission of light from the light emitter based on the electric signal.

An encoder system includes a configurable detector array, wherein the configurable detector array includes a plurality of detectors. The encoder system may also include a memory operable to store a partition map that defines a state for each of the plurality of detectors. The encoder system may also include an emitter operable to generate a flux modulated by a motion object, wherein the configurable detector array is operable to receive the flux and generate respective current outputs for each of the detectors in response to the flux. In an embodiment, the current outputs from detectors having a same state are grouped together. The encoder system may also include one or more current duplicators to duplicate the current outputs from detectors having one state to group with the current outputs from detectors having a different state. The encoder system may also adjust weights of the current outputs.

There is provided a light control circuit including a light detector, a frequency detector, an error amplifier, an NMOS driver and a light source. The frequency detector identifies a signal frequency according to detected voltage signals outputted by the light detector and generates a control signal accordingly. The NMOS driver changes a drive current of the light source according to an output of the error amplifier. The error amplifier changes a bandwidth thereof according to the control signal from the frequency detector to regulate a response time of the drive current of the light source.

An index grating of an optical encoder provided by the invention has a main technical feature of increasing a ratio of light-transmissible area of a grating per unit area, thereby increasing a light source utilization efficiency and a signal intensity, and reducing light-blocking ratio caused by dust and other foreign matters, thereby reducing a degree of influence on light intensity, so as to improve a sensing precision of the optical encoder.

A rotary angle sensor for an electric power assisted steering system of a motor vehicle, wherein the rotary angle sensor comprises an optical sensor unit with a light source, optical components and a photodetector and a disc with an optical pattern, wherein the optical sensor unit and the disc are configured to rotate relative to each other around a rotary axis, and wherein the optical sensor unit is configured such that light reflected from the optical pattern is measured by the photodetector, wherein the optical pattern comprises steps and spaces separating the steps, such that light reflected by steps and spaces destructively interferes leading to an intensity modulation of the reflected light according to an optical pattern which encodes a binary type code for the rotary angle of the disc.

There is provided an optical encoder including a photodiode array and a code disk opposite to each other. The photodiode array includes at least three sets of position photodiodes and two index photodiodes arranged transversally. The two index photodiodes are adjacently arranged at the same side of the at least three sets of position photodiodes. A first set of position photodiodes and a last set of position photodiodes of the at least three sets of position photodiodes are partially covered to alleviate the total harmonic distortion. The rest position photodiodes of the at least three sets of position photodiodes other than the first and last sets of position photodiodes are not covered.

A digital encoder with a screen includes a key body, and a display assembly is configured inside the key body. The display assembly includes a display carrier assembly, display element configured on the display carrier assembly and display circuit element configured in the display carrier assembly, where one side of the display assembly is in connection with a rotating assembly movably configured on a carrier housing, and a rotary encoder sensor and pressing element are configured between the rotating assembly and carrier housing, thereby allowing the assembly of the key body to be more convenient through modulization structures, and allowing the key body to have multiple functions of display, press and rotation at the same time to increase use convenience.

A position-measuring device includes a scale having first and second measuring graduations, which each include graduation structures that respectively extend parallel to first and second directions. A first scanning unit is associated with the first measuring graduation, and second and third scanning units are associated with the second measuring graduation. A fourth scanning unit is associated with the first or second measuring graduation. In the former case, a first straight connecting line running through scanning locations of the first and fourth scanning units and a second straight connecting line running through scanning locations of the second and third scanning units are parallel or form a predetermined angle therebetween that is not equal to a sum of the angles of the first and second directions. In the latter case, the scanning locations of the second, third and fourth scanning units do not lie on a common straight connecting line.

In this optical rotary encoder, detection tracks of a rotating disc are irradiated with detection light emitted from a light-emitting element. An optical signal obtained via slits in the detection tracks passes through a slit pattern in a fixed slit plate and is received by light-receiving surfaces of a light-receiving element. The slit pattern in the fixed slit plate is formed so as to fit into a range of an effective spot of the detection light. An LED or other light-emitting element that has a small effective spot diameter can be used, which is advantageous in terms of reducing costs and making the device more compact.