In some examples, an optical encoder may consist of a light source that shines light onto a wheel which then reflects the light onto a sensor. Using information encoded in the reflected light, the rotation of the wheel may be determined. In some examples, rotation of the wheel may be determined by detecting an encoding pattern in light reflected from an exterior surface of the wheel. In some examples, the encoding pattern can be a pattern of light and dark stripes. In some examples, a pattern of light stripes can be generated from light reflecting off of reflective portions of the wheel. Some examples of the disclosure relate to using a surface topology for a wheel that can be used to generate an encoding pattern of light and dark stripes in light reflected from the surface of the wheel, even when the surface of the wheel is uniformly reflective.

An optical safety sensor is inexpensively implemented. An optical safety sensor includes: a plurality of light projectors/receivers (a first light projector/receiver and a second light projector/receiver), which includes light projecting portions and light receiving portions; distance measurement portions, which measure distances using the time from light projecting to light receiving; and detection portions, which detect, based on measurement results, an abnormality occurring in any one of the plurality of light projectors/receivers; each of the light receiving portion provided in the plurality of light projectors/receivers receives reflected light caused by the light projected from the light projecting portions of all the plurality of light projectors/receivers.

An optical safety sensor is inexpensively implemented. An optical safety sensor includes: a plurality of light projectors/receivers (a first light projector/receiver and a second light projector/receiver), which includes light projecting portions and light receiving portions; distance measurement portions, which measure distances using the time from light projecting to light receiving; and detection portions, which detect, based on measurement results, an abnormality occurring in any one of the plurality of light projectors/receivers; each of the light receiving portion provided in the plurality of light projectors/receivers receives reflected light caused by the light projected from the light projecting portions of all the plurality of light projectors/receivers.

A timing apparatus, system, and method are provided to determine a position of a rotating object in a device, such as an engine, and control the device according to the determined position of the rotating object. Light is emitted from a light source onto a reflecting region on a portion of the rotating object. Light is reflected off the reflecting region of the rotating object and detected as the rotating object rotates. Intensity of the reflected light is measured, via a microcontroller, and the position of the rotating object is determined according to the intensity of the detected light. A signal is generated that corresponds to the intensity of the detected light associated with the determined position of the rotating shaft. The reflecting region has a feature configured to effect a change in the intensity of the reflected light as the rotating object rotates. The microcontroller is configured to determine the determined position and to utilize the determined position and the change in the signal to control operating characteristics of the device.

An optical microcavity device (10), an alignment structure for an optical device, and a method for aligning an optical device are disclosed. The optical microcavity device (10) comprises: a first optical reflector (20); a second optical reflector (30) opposed to the first optical reflector (20) along an optical axis (40), the first and second optical reflectors (20, 30) being spaced from each other forming an open space therebetween; wherein the first optical reflector (20) comprises a first cavity reflector (22) and a first alignment reflector (24), wherein the second optical reflector (30) comprises a second cavity reflector (32) and a second alignment reflector (34), the second cavity reflector (32) comprising a recess to provide an optical microcavity between the first and second cavity reflectors (20, 30), the optical microcavity having an optical cavity length of at most 50 μm and/or an optical mode volume of 100 μm3 or less; an EM radiation source (50) configured for illuminating the optical microcavity with EM radiation (52) to cause multi-pass interference within the optical microcavity; and an alignment system configured to: illuminate the first and second alignment reflectors (24, 34) of the first and second optical reflectors (20, 30) to generate an optical interference pattern (74); detect the optical interference pattern (74); and determine a relative orientation and/or separation of the first and second optical reflectors (20, 30) based on the detected optical interference pattern (74); the alignment system further comprising an actuator system (100, 102) configured to move the first and second optical reflectors (20, 30) relative to each other to change the relative orientation and/or separation of the first and second optical reflectors (20, 30) based on the determined relative orientation and/or separation. At least one of the first and second alignment reflectors (20, 30) may comprise an alignment structure comprising at least two reflective surface portions having different angular orientations.

The range of operating angles of a position transducer is widened, and its signal-to-noise ratio is improved. The position transducer includes a light source and a detector including at least one pair of photodiodes (PDs) disposed on a predetermined circle. The detector receives light emitted from the light source to output a signal varying depending on the areas of regions where the light is received on two PDs forming a pair. The PDs are formed on separate chips, respectively, and the chips are disposed on a substrate so that one or more pairs of PDs surround the entirety of a predetermined region and have an annular shape as a whole.

An apparatus includes an operation ring including first and second tooth portions, a first unit including an emitting portion that emits light to the first tooth portion and a receiving portion that receives emitted light passing through slits of the first tooth portion, and a second unit including an emitting portion that emits light to the second tooth portion and a receiving portion that receives emitted light passing through slits of the second tooth portion. Rotation of the ring is detected based on detection results by the first and second units. The ring has grooves formed at a first period in a circumferential direction thereof, and between the first and second tooth portions in a direction parallel to a rotation axis of the ring. The apparatus further includes a sliding member that is biased in a radial direction of the ring and slides over the grooves as the ring rotates.

An apparatus includes an operation ring including first and second tooth portions, a first unit including an emitting portion that emits light to the first tooth portion and a receiving portion that receives emitted light passing through slits of the first tooth portion, and a second unit including an emitting portion that emits light to the second tooth portion and a receiving portion that receives emitted light passing through slits of the second tooth portion. Rotation of the ring is detected based on detection results by the first and second units. The ring has grooves formed at a first period in a circumferential direction thereof, and between the first and second tooth portions in a direction parallel to a rotation axis of the ring. The apparatus further includes a sliding member that is biased in a radial direction of the ring and slides over the grooves as the ring rotates.

An optical position-measuring device for determining the position of a first object relative to a second object movable relative to the first object along a measurement direction includes a scale with a measuring graduation connected to the first object and extending along the measurement direction. A scanner is connected to the second object and includes a fiber-optic array including optical fibers. The fiber-optic array is configured as a fiber-optic plate having an image-input face facing the scale and an image-output face facing the detector array. The fiber-optic array transmits a light pattern into a detection plane of the detector array. An interstitial medium is disposed between the image-output face of the fiber-optic plate and the detector array to ensure that an amount of deflection that the beams exiting the image-output face undergo on a path to the detector array is smaller than in a case without the interstitial medium.

An optical position-measuring device for determining the position of a first object relative to a second object movable relative to the first object along a measurement direction includes a scale with a measuring graduation connected to the first object and extending along the measurement direction. A scanner is connected to the second object and includes a fiber-optic array including optical fibers. The fiber-optic array is configured as a fiber-optic plate having an image-input face facing the scale and an image-output face facing the detector array. The fiber-optic array transmits a light pattern into a detection plane of the detector array. An interstitial medium is disposed between the image-output face of the fiber-optic plate and the detector array to ensure that an amount of deflection that the beams exiting the image-output face undergo on a path to the detector array is smaller than in a case without the interstitial medium.