Abstract: A chromatic confocal point sensor (CPS) system and associated methods are provided for measuring holes. A CPS optical pen includes a beam dividing deflecting element that directs measurement light simultaneously along at least three directions to the interior surface of the hole. A CPS electronics portion comprises a light generator, a spectrometer, and a signal processor. In operation, the CPS pen directs measurement light to the interior surface along the at least three directions, and the spectrometer receives measurement light reflected from those directions back through the pen and provides a spectral intensity profile comprising spectral peak components corresponding to distances to the interior surface along those directions. The hole characteristic may be determined based at least partially on those distances. The CPS pen may be used as a probe on a coordinate measuring machine (CMM). The CPS pen does not require rotation in a hole to measure the hole.

Abstract: A chromatic confocal point sensor (CPS) system and associated methods are provided for measuring holes. A CPS optical pen includes a beam dividing deflecting element that directs measurement light simultaneously along at least three directions to the interior surface of the hole. A CPS electronics portion comprises a light generator, a spectrometer, and a signal processor. In operation, the CPS pen directs measurement light to the interior surface along the at least three directions, and the spectrometer receives measurement light reflected from those directions back through the pen and provides a spectral intensity profile comprising spectral peak components corresponding to distances to the interior surface along those directions. The hole characteristic may be determined based at least partially on those distances. The CPS pen may be used as a probe on a coordinate measuring machine (CMM). The CPS pen does not require rotation in a hole to measure the hole.

Abstract: A flexible optical displacement encoder configuration uses a source grating to illuminate a scale with structured light such that light from the scale is modulated with a beat frequency envelope which may have a relatively coarse pitch that matches a desired detector pitch. An imaging configuration provides spatial filtering to remove the high spatial frequencies from the modulation envelope to provide a clean signal in the detected fringe pattern. This combination of elements allows an incremental scale track pattern with a relatively finer pitch (e.g., 4, 5, 8 microns) to provide fringes with a coarser pitch (e.g., 20 microns) at a detector. Various scale resolutions can use a corresponding source grating such that all combinations can produce detector fringes that match the same economical detector component.

Abstract: A miniaturized optical encoder capable of obtaining a sufficient amount of light in the light receiving element is provided. An optical encoder 1 includes a scale 2 having a scale track 2? and a readhead 3 having a light source 31 that emits light to the scale track 2?, a scale-side lens 32 that transmits the light emitted from the light source 31 to the scale track 2?, and a light receiving element 33 that receives the light reflected by the scale track 2? through the scale-side lens 32. The light source 31 is arranged between the scale-side lens 32 and the light receiving element 33. An optical axis Lsrc of the light source 31 is matched with an optical axis Ls of the scale-side lens 32 in a reading direction of the scale 2 and is separated from an optical axis Ls of the scale-side lens 32 by a predetermined distance D in a direction perpendicular to the reading direction of the scale 2.

Abstract: A miniaturized optical encoder capable of obtaining a sufficient amount of light in the light receiving element is provided. An optical encoder 1 includes a scale 2 having a scale track 2? and a readhead 3 having a light source 31 that emits light to the scale track 2?, a scale-side lens 32 that transmits the light emitted from the light source 31 to the scale track 2?, and a light receiving element 33 that receives the light reflected by the scale track 2? through the scale-side lens 32. The light source 31 is arranged between the scale-side lens 32 and the light receiving element 33. An optical axis Lsrc of the light source 31 is matched with an optical axis Ls of the scale-side lens 32 in a reading direction of the scale 2 and is separated from an optical axis Ls of the scale-side lens 32 by a predetermined distance D in a direction perpendicular to the reading direction of the scale 2.

Abstract: An extended range focus sensor is provided. In various embodiments, the focus sensor may include a relay lens assembly to image a plane between an objective lens and the relay lens arrangement to a plane near an entrance pupil of a focus detector arrangement of the focus sensor. In some embodiments, the objective lens pupil is imaged onto the focus detector entrance pupil. In some embodiments, an illumination beam passes through the relay lens arrangement and is magnified on its way to be output by the objective lens, and the reflected focus detection beam passes back through the objective lens and the relay lens arrangement and is reduced prior to being input to the focus detector arrangement. In some embodiments, the focus detector arrangement may comprising a broad range focus detector combined with a high resolution Shack-Hartmann focus detector, and in others a single extended range Shack-Hartmann focus detector is used.

Abstract: A photoelectric encoder has a telecentric optical system in which a first lens and an aperture located at a focal position of the first lens are interposed between a main scale and a photoreceptor. At least a second lens is interposed between the aperture and the photoreceptor with a focus of the second lens on the aperture, thereby constituting a bilateral telecentric optical system. This makes it possible to improve the signal detection efficiency and increase the assembly tolerance.

Abstract: An extended range focus sensor is provided. In various embodiments, the focus sensor may include a relay lens assembly to image a plane between an objective lens and the relay lens arrangement to a plane near an entrance pupil of a focus detector arrangement of the focus sensor. In some embodiments, the objective lens pupil is imaged onto the focus detector entrance pupil. In some embodiments, an illumination beam passes through the relay lens arrangement and is magnified on its way to be output by the objective lens, and the reflected focus detection beam passes back through the objective lens and the relay lens arrangement and is reduced prior to being input to the focus detector arrangement. In some embodiments, the focus detector arrangement may comprising a broad range focus detector combined with a high resolution Shack-Hartmann focus detector, and in others a single extended range Shack-Hartmann focus detector is used.

Abstract: An ultra-miniature interferometric fiber-optic encoder readhead for sensing displacement of a very fine pitch scale grating is disclosed. The readhead includes a source grating that diffracts diverging source light into +/? 1st order beams, a pair of mirrors that reflect the +/? 1st order beams to converge toward the scale grating. The +/? 1st order scale light beams are reflectively diffracted back from scale grating to return to the mirrors, and are then reflected to converge back toward the light source and a set of adjacent fiber-optic receiver channels. An interference field generating grating positioned in front of the receiver channels produces interference fringes having a desired pitch. Movement of the interference fringes is sensed by the fiber-optic receiver channels to provide displacement information. The readhead may be configured so that primarily or only +/? 1st order light reaches the receiver channels.

Abstract: An ultra-miniature interferometric fiber-optic encoder readhead for sensing displacement of a very fine pitch scale grating is disclosed. The readhead includes a source grating that diffracts diverging source light into ±1st order beams, a pair of mirrors that reflect the ±1st order beams to converge toward the scale grating. The ±1st order scale light beams are reflectively diffracted back from scale grating to return to the mirrors, and are then reflected to converge back toward the light source and a set of adjacent fiber-optic receiver channels. An interference field generating grating positioned in front of the receiver channels produces interference fringes having a desired pitch. Movement of the interference fringes is sensed by the fiber-optic receiver channels to provide displacement information. The readhead may be configured so that primarily or only ±1st order light reaches the receiver channels.

Abstract: A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.

Abstract: A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.