The invention concerns a method for determining absolute coding represented by code elements of an optical code track, with illumination of the absolute coding with light, modulating of some of the illuminating light on code elements, determining of the absolute coding as modulated light and continuously varying modulation of the light on neighboring code elements.

A scale is provided with a two-level code pattern according to a pseudo random code sequence along a length measurement direction. Each code of the two-level code pattern indicates a code “1” or “0”, each code includes two bits, and each bit of the two bits is L or H. The code “1” is represented by an A pattern which is a combination of L and H, and the code “0” is represented by a B pattern which is a combination of L and L or by a C pattern which is a combination of H and H. When the codes “0” are continued, the B pattern and the C pattern are alternately used. The scale is commonly used in a reflective type encoder or transmissive type encoder. A detection head part includes an inversion processing unit which performs inversion processing to a detection image of the scale as required.

A robot includes a first member, a second member that is provided to be turnable about a turning axis with respect to the first member, marks that are disposed around the turning axis on a surface of the second member, and a mark detection portion that is disposed in the first member and detects the marks.

There is provided an absolute encoder advantageous in accuracy of an output thereof against a defect in a scale thereof. In the absolute encoder, a detector detects a part of an array of marks of the scale, and outputs a data sequence corresponding to the part. A processor stores information indicating a correspondence between each of a plurality of code sequences and an absolute coordinate of motion of the scale, and outputs information of the absolute coordinate based on the data sequence and the information. The processor detects an error of the data sequence, and performs rewriting of the information based on the detected error.

A method of applying a marking onto a metrological scale. The method includes locating one or more markings on the scale substrate in a provisional state; checking whether the one or more markings located on the scale substrate are acceptable; and finalizing the one or markings which are acceptable so as to transform the one or more markings into a finalized state.

A rotary encoder for detecting the angle of rotation of a first rotatable shaft, with a first mark which is coupled with the first shaft, a second mark which is coupled with the second rotatable shaft, a third mark which is coupled with the second shaft, a fixed fourth mark and means for detecting a passage of the third mark though a vicinity of the fourth mark and means for detecting a coincidence of the angles of rotation of the first and the second marks.

An absolute position detection apparatus includes a calculator configured to generate, based on a detection signal, a first signal, and a second signal. A relative movement range of the scale and the sensor includes a boundary between adjacent detection units in the first signal such that at least one of the boundary is included in each of a plurality of areas in the relative movement range. The calculator is configured to specify a detection unit, to be used to calculate the absolute position, in the first signal based on a code of each detection unit of the second signal in an area that includes the boundary of the plurality of areas.

An encoder apparatus includes an encoder and a processor. The encoder includes a scale portion, a light emitting portion, and a light receiving portion. The scale portion includes a first track and a second track. The processor obtains a plurality of candidate values of a gap between the light emitting portion and the scale portion on a basis of an amplitude of a first signal obtained by receiving light reflected on or transmitted through the first track by the light receiving portion. The processor determines a measured value from among the plurality of candidate values on a basis of an amplitude of a second signal obtained by receiving light reflected on or transmitted through the second track by the light receiving portion.

The invention relates to a detector device having pixels in a two-dimensional arrangement, the detector device comprising row pixels, a row readout wiring for each row of said row pixels and a column select wiring for each column of said row pixels, as well as column pixels, a column readout wiring for each column of said column pixels and a row select wiring for each row of said column pixels. Analog-to-digital converters adapted for row-parallel and column-parallel operation are connected to the readout wirings, and simultaneously one or more columns of row pixels for row parallel readout and one or more rows of column pixels for column parallel readout can be selected. The invention further relates to a positioning code and to a position detecting method.

A position-measuring device includes a carrier body having a first and second measuring graduations and a reference mark. The first and second measuring graduations include graduation structures periodically arranged along first and second measurement directions, respectively, that are perpendicular to each other. The graduation structures of the first measuring graduation each extend parallel to a first direction and the reference mark extends in a second direction that forms an angle different from 0° with the first direction. First and second scanners are configured to scan the first and second measuring graduations and generate first and second scanning signals, respectively. A third scanner is configured to scan the reference mark and generate a reference pulse. The position-measuring device is configured such that a phase angle of the reference pulse is determined as a function of the first scanning signals and the reference pulse.