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.

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.

An encoder includes a rotatable encoder disc. A clamp is fixed to the encoder disc to rotate therewith. The clamp includes an arcuately extending body presenting a radially inner face and arcuately spaced apart ends defining a gap therebetween. The inner face extends along a clamping path and engages a rotating component to secure the clamp to the rotating component to rotate therewith. The clamp includes an adjustment mechanism for modifying an arcuate extent of the gap by shifting the ends relative to one another and, in turn, modifying the clamping path. The body defines a radially extending cutout facilitating bending of the body in association with expansion or contraction of the gap and modification of the clamping path. The clamp includes a raised boss extending from a front face thereof. The boss presents a contact face spaced axially from the front face and fixedly engaging the encoder disc.

A controller for use with a position encoder includes one or more motion inputs suitable to couple to motion outputs of the position encoder and a limit input suitable to couple to a limit output of the position encoder. The controller also includes an actuator interface, a command interface, and circuitry coupled to the one or more motion inputs, the limit input, the actuator interface, and the command interface. The circuitry is configured to receive a command through the command interface to move a structural member coupled to the position encoder to a new position and control an actuator through the actuator interface to move the structural member toward the new position. A limit indication is received from the position encoder through the limit input and the controller stops or reverses the movement of the structural member by controlling the actuator in response to receiving the limit indication.

There is provided an optical encoder including an encoding medium, a substrate, a light source and a light sensor. The encoding medium includes an index track and a position track. The light source is arranged at a first surface of the substrate to emit light toward the index track and the position track. The light sensor is arranged at a second surface of the substrate, and has a first light sensing region and a second light sensing region for receiving reflective light respectively from the index track and the position track.

An optical detection system includes a marker product and an optical encoding device. The marker product includes a substrate and at least one structural portion. The structural portion has a first surface, a second surface and a dividing axis. The first surface and the second surface are arranged on opposite sides of the dividing axis. A sidelong direction aligning the first surface with the second surface is parallel to a moving direction between the optical encoding device and the marker product. The optical encoding device is disposed adjacent by the marker product. The optical encoding device includes an optical projector and an optical encoder. The optical projector is configured to project the optical detecting signal onto the marker product. The optical encoder is configured to receive an optical reflecting signal from the marker product and encode intensity variation of the optical reflecting signal into digital data.

In a rotary motion detecting device that outputs a signal corresponding to rotary motion of a rotary disk coupled to a shaft, a boss is fixed to the shaft, the boss is fixed to one surface of the rotary disk, and one of the boss and the shaft is a hole member having a hole formed therein and the other is an inserted member that is inserted in the hole. The hole member has an inner periphery (inner diameter) that is larger than an outer periphery (outer diameter) of the inserted member so that the shaft can be vertical to the rotary disk without being restricted by the boss.

Provided is a rotational positioning device capable of positioning a rotational angle at a target angle position with high precision. A rotational positioning device is provided with: a housing; a rotational member which is rotatable about a rotational member axial line and at least a part of which is accommodated in the housing; and at least one sensor installed in the housing. A graduated scale with a plurality of scale marks is formed integrally with the rotational member along the circumferential direction of the rotational member. The at least one sensor detects an angle change amount due to rotation of the rotational member on the basis of the plurality of scale marks. The rotational member is positioned at the target angle position on the basis of the angle change amount.

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.

The rotation detection apparatus including an annular member, a scale member having flexibility and being fixed to a circumferential portion of the annular member, and a detector facing the scale member and configured to detect relative rotation between the scale member and the detector. The circumferential portion of the annular member includes multiple convex portions and multiple concave portions along a circumferential direction of the annular member. The scale member is in contact with the multiple convex portions. Both ends, in the circumferential direction, of the scale member are fixed to the circumferential portion.