An encoder apparatus including a readhead for reading a reflective scale located adjacent the readhead. The readhead includes a circuit board on which a sensor including one or more photodiodes for detecting light reflected from a scale located adjacent the readhead is mounted, and at least one light emitting element. The light emitting element is mounted to the circuit board via a light emitting element support structure which holds the light emitting element away from the circuit board and the sensing plane of the sensor, and at least a part of which extends over the sensor.

An image pickup apparatus which is capable of stably detecting rotating operations of a rotary ring provided on an outer periphery of a lens barrel or the like. A holding member is provided on an inner periphery of the rotary ring to hold the rotary ring. A rotation detecting member detects a rotation direction and a rotation amount of the rotary ring when the rotary ring has been rotated. An urging member urges the rotary ring against the holding member in an urging direction perpendicular to a rotational axis of the rotary ring. A detecting direction of the rotation detecting member and the urging direction of the urging member are parallel to each other.

An encoder is provided that is capable of suppressing accuracy deterioration even if a scale is disposed in a tilted manner with respect to a receiving unit by being rotated around an axis (i.e., a rotation axis) orthogonal to a receiving surface. The encoder 1 includes scale 2 and detection head 3. The detection head 3 includes light source (transmitting unit) 4 and light-receiving unit (receiving unit) 5. The light-receiving unit includes light-receiving surface (receiving surface) 50 and converts light received at the light-receiving surface 50 into differential detection signals with two phases and outputs the same. The light-receiving surface 50 includes element array group 7 including four element arrays 71-74 provided in a parallel manner along an orthogonal direction, with each element array 71-74 including a plurality of light-receiving elements (receiving elements) 500. The plurality of element arrays 71-74 in the element array group 7 are disposed at positions where the sum of: (i) a distance in the orthogonal direction from a reference position to a positive phase signal element array 71, 72; and (ii) a distance in the orthogonal direction from the reference position to the negative phase signal element array 73, 74, is the same for all the phases of the at least two phases.

There is provided an operating method of an optical positioning system including: capturing an image frame of a detected surface, which has interleaved bright regions and dark regions, using a field of view and a shutter time of an optical sensor; counting a number of edge pairs between the bright regions and the dark regions that the field of view passes; calculating an average value of the image frame; calculating a ratio between the calculated average value and the shutter time; determining that the field of view is aligned with one of the dark regions when the ratio is smaller than a ratio threshold; and determining that the field of view is aligned with one of the bright regions when the ratio is larger than the ratio threshold.

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.

An electronic device is described. The electronic device may include a housing, a rotatable crown, and a self-mixing interferometry (SMI) sensor positioned within the housing. The rotatable crown may include an array of retroreflective surface features that reflect incident light back to a light source. Each retroreflective surface feature of the array of retroreflective surface features may be formed as a corner-cube with three perpendicular faces. The SMI sensor or associated processing electronics may compare originally emitted light with reflected light to identify a movement or distance of the rotatable crown with respect to the SMI sensor.

A reflective optical encoder has a hub member mounted on a rotation shaft, and a circular scale plate fixed to the hub member by an adhesive and having, on a front surface thereof, a pattern composed of high reflection portions having a high light reflectance and low reflection portions having a low light reflectance. Further, a step is provided at an outer peripheral portion of the hub member, and an outer diameter of the scale plate is larger than an outer diameter at an outermost peripheral portion of an adhesive surface of the hub member in which the scale plate and the hub member are bonded.

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.

The range of operating angles of a position transducer is widened, and its signal-to-noise ratio is improved. The position transducer includes a light source and a detector including at least one pair of photodiodes (PDs) disposed on a predetermined circle. The detector receives light emitted from the light source to output a signal varying depending on the areas of regions where the light is received on two PDs forming a pair. The PDs are formed on separate chips, respectively, and the chips are disposed on a substrate so that one or more pairs of PDs surround the entirety of a predetermined region and have an annular shape as a whole.

An encoder includes a scale and a sensor. The scale has first and second absolute patterns. The sensor includes a light source, and first and second absolute light receivers. The first and second absolute light receivers receive light from the first and second absolute patterns, respectively. The first absolute light receiver receives light from the first pattern and includes first and second light receiving elements. Each first light receiving elements outputs a first signal with a first phase. Each second light receiving elements outputs a first signal with a second phase. The first and second light receiving elements are arranged alternately. The second absolute light receiver includes third and fourth light receiving elements. Each third light receiving element outputs a second signal with the first phase. The third and fourth light receiving elements are arranged alternately. Each fourth light receiving element outputs a second signal with the second phase.