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 system includes: (a) a flexible intermediate transfer member (ITM) including multiple layers and markers including: (i) a structure engraved, in at least one of the layers, at respective marking locations along the ITM, and (ii) at least part of the structure is filled with a filling material that changes one or both of optical and magnetic properties of the ITM, the ITM includes an outer layer for receiving ink droplets, and transferring the ink image to a target substrate, (b) sensing assemblies disposed at respective predefined locations relative to the ITM, and configured to produce signals indicative of respective positions of the markers, and (c) a processor, which is configured to receive the signals, and based on the signals, to control a deposition of the ink droplets on the ITM, and the processor is configured to detect a deformation of the ITM based on the first and second signals.

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.

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.

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.

A sealed encoder module for mounting onto a machine so as to measure relative displacement of first and second parts of the machine. The sealed encoder module can comprise, a scale, a readhead comprising a scale signal receiver, and an integral protective housing which encapsulates at least the scale and said scale signal receiver. The sealed encoder module can be configured to determine and output diagnostic information regarding a scale signal detected by the readhead.

Non-contact sensors include an image sensor configured to capture image data of a portion of a surface of a rotatable shaft and an electronic control unit communicatively coupled to the image sensor. The electronic control unit is configured to receive image data having a plurality of frames from the image sensor and store the image data in a memory component of the electronic control unit, determine a transformation in image space between one or more surface features that appear in a first frame of the image data and the same one or more surface features that appear in a second frame of the image data, determine a rotational position of the rotatable shaft at a time of capture of the second frame of the image data based on the transformation and a quantitatively characterized relationship between image space and object space, and store the rotational position of the rotatable shaft.

A method of assembling a device including, taking a casing including a body having an opening and a lid for the opening, locating at least one electronic component within the body; locating a first end of a cable for electrically connecting the electronic component within the body to an external device, and deforming at least one of the body and the lid so as to secure the lid to the body and such that the cable is secured to the casing by the lid.

An encoder apparatus including a reflective scale and a readhead. The readhead includes at least one light emitting element, at least one sensor and at least one optical device, which together with the scale form an optical system in which the optical device forms an image of an illuminated region of the reflective scale onto the sensor. The system's optical path, from the light emitting element to the sensor, passes through the optical device on its way toward and after reflection from the scale. and includes an unreflected optical path between the light emitting element and the optical device and an unreflected optical path between the optical device and the sensor.

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.