Some embodiments of the invention include an area position code pattern, comprising an arrangement of code marks in a basic grid. At least one portion of said position code pattern is readable by a matrix sensor for determining positions. According to some embodiments of the invention, the position code pattern is embodied with a first absolute code sequence in a stringing-together of the code marks in a first line direction of the basic grid as first line on the area to be encoded and the code marks are encoded with a second absolute code sequence in the line direction along a second line which follows the first line. The first line and the second line form a line pair and the two absolute code sequences are each arranged offset in the first direction in the basic grid in a subsequent line pair.

An optical position-measuring device for absolute position determination includes a material measure extending along a measurement direction and including an incremental graduation and an absolute code. A scanning unit movable relative to the material measure has a light source, a scanning grating for optically scanning the incremental graduation and a detector device. The detector device includes an incremental detector for generating incremental signals from the optical scanning of the incremental graduation and an absolute detector for generating absolute signals from optical scanning of the absolute code. A common detection plane is located at a defined perpendicular distance from the scanning grating and/or a periodicity of a fringe pattern on the incremental detector is selected such that, in the event of scattering contamination in a region of the material measure and/or the scanning grating, amplitudes of the incremental signals and the absolute signals drop off equally.

An optical position encoder includes a scale having multiple tracks separated in a direction perpendicular to travel, the tracks including an incremental track and an absolute track, the scale interacting with an incident first light beam to generate a second light beam having components carrying respective optical patterns produced by the incremental track and absolute track respectively. The encoder further includes a set of optical detectors including at least first and second detector arrays of differing properties to detect the respective optical patterns produced by the incremental track and absolute track respectively, each of the first and second detector arrays spanning multiple tracks of the scale and configured to respond to a respective detector-specific component of the second light beam more strongly than to another component of the second beam specific to another of the detector arrays.

Provided is a position detecting apparatus, including: a scale including pattern arrays formed in different cycles in a movement direction; an obtaining unit configured to obtain signals in accordance with a the plurality of pattern arrays; a phase calculator configured to calculate a phase of signals; a synchronism calculator configured to calculate a relative positional relationship between the obtaining unit and the scale by performing synchronism calculation of the phases calculated by the phase calculator; a synchronization error calculator configured to calculate a synchronization error in the synchronism calculation; and a determining unit configured to determine whether or not the synchronism calculation is normal by comparing the synchronization error and a predetermined threshold value with each other.

An encoder includes a plurality of slit tracks, a point light source, a first light-receiving array, a second light-receiving array, and a third light-receiving array. The plurality of slit tracks respectively comprises a plurality of reflection slits arranged along a measurement direction. The point light source is configured to emit diffusion light to the plurality of slit tracks. The first light-receiving array is configured to receive light reflected by the slit track comprising an incremental pattern. The second light-receiving array is configured to receive light reflected by the slit track comprising an incremental pattern longer in pitch than other incremental patterns. The third light-receiving array is configured to receive light reflected by the slit track comprising an absolute pattern.

There is provided a phase shifter circuit of an optical encoder. The phase shifter circuit receives a first signal, a second signal, a third signal and a fourth signal sequentially having a 90-degree phase shift, and includes a first cascaded resistor string, a second cascaded resistor string, a third cascaded resistor string and a fourth cascaded resistor string. The first, second, third and fourth cascaded resistor strings respectively delay the first, third, second and fourth signals by selecting a switch connected at a tap-out node of the first, second, third and fourth cascaded resistor strings to correct phase deviations between incremental signals and an index signal and/or between incremental signals.

There is provided a phase shifter circuit of an optical encoder. The phase shifter circuit receives a first signal, a second signal, a third signal and a fourth signal sequentially having a 90-degree phase shift, and includes a first cascaded resistor string, a second cascaded resistor string, a third cascaded resistor string and a fourth cascaded resistor string. The first, second, third and fourth cascaded resistor strings respectively delay the first, third, second and fourth signals by selecting a switch connected at a tap-out node of the first, second, third and fourth cascaded resistor strings to correct phase deviations between incremental signals and an index signal and/or between incremental signals.

A high-resolution encoder device to measure and retrievably encode the relative position of a first part P with a second part S comprises sensible elements on part P, said sensible elements providing a variable property for sensing, such that said variable property varies over a length of said part P, a number n of sensors for sensing said variable property, said sensors being separate from each other and disposed on part S, said sensors configured to output signals in accordance with said sensing, and a processing unit connected to receive said signals from each of said n sensors and configured for succeeding ones of said relative positions to form a vector having entries from each sensor respectively, the vector defining said relative positions respectively.

There is provided a phase shifter circuit of an optical encoder. The phase shifter circuit receives a first signal, a second signal, a third signal and a fourth signal sequentially having a 90-degree phase shift, and includes a first cascaded resistor string, a second cascaded resistor string, a third cascaded resistor string and a fourth cascaded resistor string. The first, second, third and fourth cascaded resistor strings respectively delay the first, third, second and fourth signals by selecting a switch connected at a tap-out node of the first, second, third and fourth cascaded resistor strings to correct phase deviations between incremental signals and an index signal and/or between incremental signals.