摘要:
An encoder having a code carrier, light source, and detector is disclosed. The code carrier includes a track that emits light at each of a plurality of track points on the track when that track point is illuminated with light having a predetermined spectrum. Each of the track points emits light having a spectrum that is different from the spectrum emitted by others of the track points. The light source illuminates a portion of the track with light of the predetermined illumination spectrum. The detector provides a plurality of signals indicative of the spectrum of light leaving the portion of the track when the portion includes one of the track points. The code carrier moves with respect to the detector, and the signals define the relative position of the code carrier with respect to the detector.
摘要:
An optical unit includes an optical emitter receiving an optical emitter current, an optical sensor receiving an optical sensor current and light from the optical emitter and in response thereto outputting at least one signal indicating relative movement between the optical unit and an optical code scale, and an optical sensor current detector comparing the optical sensor current to a reference value. In response to the optical sensor current being different than the reference value, the optical sensor current detector outputs an optical sensor current detector signal. The optical sensor current detector signal indicates the presence of a contaminant in a light path from the optical emitter to the optical sensor, and is used to regulate the current to the optical emitter so as to counteract the negative effects of the contaminant in the light path.
摘要:
Optical encoders having one or more of a number of disclosed features are disclosed. The features of the optical encoder in accordance with the present invention include a symmetrical (for example, circular) emitter; baffle between the emitter and a detector; double-dome or single-dome encapsulant; multiple detector; and multiple (at least three) data channels.
摘要:
There is disclosed optical encoder apparatus for removable connection with a printed circuit board. In an embodiment, the apparatus includes a light emitting component, a light detecting component, a mounting component for attaching the light emitting component thereon, and another mounting component for attaching the light detecting component thereon, wherein each of the mounting components have a removable connection with the printed circuit board. A method of assembling optical encoder apparatus is disclosed. In an embodiment, the method includes attaching a light emitting component and a terminal of a first mounting component to one another; attaching a light detecting component and a terminal of a second mounting component to one another; attaching a terminal of the first mounting component to a printed circuit board; and attaching a terminal of the second mounting component to the printed circuit board. Other embodiments are also disclosed.
摘要:
An encoder having a code strip and an emitter-detector module is disclosed. The code strip includes alternating reflective and opaque stripes. The emitter-detector module includes a housing, a lens insert, a light source and a photodetector. Light from the light source illuminates the code strip, and light reflected from the code strip is incident on the photodetector. The lens insert includes a lens that processes light generated by the light source either before the light reaches the code strip or after the light is reflected from the code strip. The lens insert mates with the housing to position the lens at a predetermined point relative to the light source or the photodetector. The housing will accept a plurality of lens inserts, each lens insert having a different lens from the others of the lens inserts.
摘要:
An encoder having a code scale and an emitter detector module is disclosed. The code scale includes alternating reflective and opaque stripes. The emitter-detector module includes a light source that generates light and directs a portion of the generated light to the imaging element and a photodetector that generates a signal representing an intensity of light having a linear polarization in a predetermined direction received by the photodetector, the light source and the photodetector are encapsulated in a transparent medium, wherein there is a gap between the transparent medium and the code scale. The predetermined direction is chosen to reduce the intensity of light received by the photodetector that is reflected from an interface between the transparent medium and the gap. A polarization filter can also be included in the light source to further improve the rejection of the light reflected from the interface of the transparent medium and the gap.
摘要:
An Enhanced Reflective Optical Encoder (“EROE”) having an emitter module for transmitting emitted optical radiation to an encoded media and a detector module for receiving reflected optical radiation from the encoded media. The EROE may include a transmissive layer covering both the emitter module and the detector module, and an optical isolation element located within the transmissive layer and located between the emitter module and the detector module. The optical isolation element reduces undesired optical radiation transmitted from the emitter module to the detector module, where the undesired optical radiation is a portion of the emitted optical radiation.
摘要:
A coding element such as a codewheel includes first and second surfaces that are configured with respect to each other and with respect to a light beam such that the light beam is reflected at the two surfaces using the optical phenomenon of total internal reflection. The coding element also includes a coding pattern that is aligned in an optical path of the light beam after the light beam has reflected off of both of the surfaces. A coding element with surfaces that reflect a light beam as a result of total internal reflection can be utilized in an encoding system that operates in transmission while the light source and the photodetector array are located on the same side of the coding element.
摘要:
An encoder for measuring the position of a rotating shaft is disclosed. The encoder includes a drum having an encoding track thereon and a detector module having a light source and a photodetector. The drum includes a cylindrical surface characterized by an axis, the drum having a surface with a normal perpendicular to the axis. The encoding track includes a plurality of alternating reflective and non-reflective stripes arranged on the cylindrical surface. The first light source illuminates the stripes at an opaque angle relative to the normal. The first photodetector is positioned to receive light from the light source that is reflected from the reflective stripes when the drum moves relative to the photodetector. In one embodiment, the drum rotates about the axis when the shaft rotates. The encoding track can be either on the inside or outside of the drum.
摘要:
An optical encoder includes an emitter, a first lens, a detector, a second lens, and a protrusion. The emitter emits light which is directed by the first lens to a code scale for reflection. The reflected light is directed by the second lens to the detector. The detector detects the reflected light from the code scale. The protrusion is between the first lens and the second lens. The protrusion defines at least one surface that refracts stray light from the emitter away from the detector. Accordingly, the stray light does not reach the detector; thus the detector can operate more effectively.