Signal transmission system for machine tools, inspection machines, and the like
AssigneeRenishaw PLC
InventorDavid K. Thomas
Life of this patent
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Abstract
Probes (18A, 18B, 18C) can be interchangeably mounted in the spindle (12) of a machine tool. Each probe has an optical signal transmission system, in which an optical signal from a light emitting diode (24) is transmitted to a receiving photodiode (26). To prevent interference between the different probe signals, each probe modulates the emitted light at a different carrier frequency. The receiver (28) contains electronic bandpass filters to separate out the different carrier frequencies. The signal information is encoded onto the optical signal by phase modulation of the carrier frequency.
Claims10
A signal transmission system for a machine tool which has a plurality of sensors for producing a signal in response to a sensed condition, the system comprising:
- a plurality of signal transmission means, one for each sensor, for transmitting data associated therewith,
- carrier generating means in each signal transmission means, for generating a carrier signal for transmission by said signal transmission means, the carrier signal of each transmission means having a different carrier frequency,
- phase modulating means in each signal transmission means, for modulating said data onto said carrier signal by modulating the phase thereof,
- receiving means for receiving the signals transmitted simultaneously by the plurality of signal transmission means, and
- a plurality of filters contained in the receiving means and corresponding in number to the plurality of signal transmission means, each filter being responsive to one of the carrier frequencies of the plurality of signal transmission means to separate the data on a corresponding carrier signal from the data on other carrier signals without interference among the carrier signals.
Dependencies are inferred from the claim text.