Single track three-channel encoder with differential index
AssigneeAvago Technologies General IP (Singapore) Pte. Ltd.
InventorsMarcin Kamil Augustyniak, Aun Choon Chong, Kek Leong Yap
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Abstract
An optical encoder is disclosed. Specifically, a three-channel encoder is disclosed which utilizes a single track for all three channels. An index channel is provided on the same optical track as the first and second channels which are used to determine incremental angular position. Thus, a more compact and simple three-channel encoder is provided.
Claims20
An encoder for use in an optical encoding system, comprising:
- an emitter configured to emit light;
- a detector configured to receive at least a portion of the light emitted by the emitter and convert the received light into one or more electrical signals which are used to generate three output signals, wherein the light used to generate the three output signals at least one of passed through and was reflected by a single optical track of a coding element, and wherein one of the three output signals comprises a differential index signal.
A system for translating physical motion of a device into an electrical signal, the system comprising:
- an encoder comprising:
- a sensor area that includes an array of incremental photodiodes, a first index photodiode, and a second index photodiode;
- a coding element having a single optical track that includes an index bar, an index window, and at least one non-index bar, the coding element being mechanically coupled to the device, the single optical track being positioned in proximity to the sensor area;
- and
- signal processing circuitry coupled to the sensor area and being configured to output at least three output signals, at least one of the three output signals corresponding to an index signal that is generated based on inputs received from the first index photodiode and the second photodiode.
A coding element configured for use in an optical encoding system, the coding element comprising:
- an optical track having an index bar, an index window, and at least one non-index bar, the index bar and index window being spaced apart from each other in such a way as to produce an index signal in addition to an A-channel output signal and a B-channel output signal.
Dependencies are inferred from the claim text.