Displacement measuring apparatus
First Claim
1. A velocity detection apparatus comprising:
- a first light detector including a first emitter that illuminates optically identifiable marks disposed on a moving body, and a first light receiver that detects light from the optically identifiable marks;
a second light detector including a second emitter that illuminates the optically identifiable marks and a second light receiver that detects light from the optically identifiable marks, wherein the second light detector is arranged at a predetermined interval from the first light detector in a moving direction of the moving body;
a reference signal generating unit that generates a reference signal having a predetermined frequency;
a time-sharing light emitting unit that allows the first emitter and the second emitter to emit light in a time-sharing manner in synchronism with the reference signal using an energization control unit that controls energization states of the first emitter and the second emitter;
a sampling unit that samples outputs of the first light detector and the second light detector in synchronism with the reference signal;
an identical point detecting unit that detects a first time at which the first light detector detects a first mark among the optically identifiable marks, and a second time different from the first time at which the second light detector detects the first mark through interpolating computation using the outputs of the first light detector and the second light detector sampled by the sampling unit; and
a velocity calculating unit that calculates a moving velocity of the moving body using the first time and the second time detected by the identical point detecting unit.
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Accused Products
Abstract
A displacement measuring apparatus including: a first light detector including a first emitter illuminating optically identifiable marks disposed on a moving body, and a first light receiver detecting light through the marks; a second light detector including a second emitter illuminating the marks and a second light receiver detecting light through the marks, wherein the second light detector is arranged at a predetermined interval from the first light detector in a moving direction of the moving body; an identical point detecting unit detecting a first timing at which the first and second light detector detecting an identical mark among the marks, and a second timing; a velocity calculating unit calculating a velocity of the moving body by using the first and second timing determined by the identical point detecting unit; and a time-sharing light emitting unit allowing the first and second emitter to emit the light in a time-sharing manner.
28 Citations
14 Claims
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1. A velocity detection apparatus comprising:
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a first light detector including a first emitter that illuminates optically identifiable marks disposed on a moving body, and a first light receiver that detects light from the optically identifiable marks; a second light detector including a second emitter that illuminates the optically identifiable marks and a second light receiver that detects light from the optically identifiable marks, wherein the second light detector is arranged at a predetermined interval from the first light detector in a moving direction of the moving body; a reference signal generating unit that generates a reference signal having a predetermined frequency; a time-sharing light emitting unit that allows the first emitter and the second emitter to emit light in a time-sharing manner in synchronism with the reference signal using an energization control unit that controls energization states of the first emitter and the second emitter; a sampling unit that samples outputs of the first light detector and the second light detector in synchronism with the reference signal; an identical point detecting unit that detects a first time at which the first light detector detects a first mark among the optically identifiable marks, and a second time different from the first time at which the second light detector detects the first mark through interpolating computation using the outputs of the first light detector and the second light detector sampled by the sampling unit; and a velocity calculating unit that calculates a moving velocity of the moving body using the first time and the second time detected by the identical point detecting unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A velocity detection apparatus comprising:
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a first light detector including a first emitter that illuminates optically identifiable marks disposed on a moving body, and a first light receiver that detects light from the optically identifiable marks; a second light detector including a second emitter that illuminates the optically identifiable marks and a second light receiver that detects light from the optically identifiable marks, wherein the second light detector is arranged at a predetermined interval from the first light detector in a moving direction of the moving body; a time-sharing light emitting unit that allows the first emitter and the second emitter to emit light in a time-sharing manner; an identical point detecting unit that detects a first time at which the first light detector detects a first mark among the optically identifiable marks, and a second time different from the first time at which the second light detector detects the first mark; and a velocity calculating unit that calculates a moving velocity of the moving body using the first time and the second time detected by the identical point detecting unit, wherein the time-sharing light emitting unit and the identical point detecting unit periodically performs; a first task that causes the first emitter to illuminate the optically identifiable marks; a second task that causes the first light receiver to detect light from the first light emitter via a predetermined point of the optically identifiable marks; a third task that causes the second emitter to illuminate the optically identifiable marks after turning off the first emitter after the first receiver detects light from the first light emitter; a fourth task that causes the second light receiver to detect light from the second light emitter via the predetermined point of the optically identifiable marks; and a fifth task that causes the second emitter to be turned off after the second light receiver detects light from the second emitter and then returns to the first task. - View Dependent Claims (12)
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13. An image forming apparatus comprising:
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a moving body; and a velocity detection apparatus comprising; a first light detector including a first emitter that illuminates optically identifiable marks disposed on a moving body, and a first light receiver that detects light from the optically identifiable marks; a second light detector including a second emitter that illuminates the optically identifiable marks and a second light receiver that detects light from the optically identifiable marks, wherein the second light detector is arranged at a predetermined interval from the first light detector in a moving direction of the moving body; a reference signal generating unit that generates a reference signal having a predetermined frequency; a time-sharing light emitting unit that allows the first emitter and the second emitter to emit light in a time-sharing manner in synchronism with the reference signal using an energization control unit that controls energization states of the first emitter and the second emitter; a sampling unit that samples outputs of the first light detector and the second light detector in synchronism with the reference signal; an identical point detecting unit that detects a first time at which the first light detector detects a first mark among the optically identifiable marks, and a second time different from the first time at which the second light detector detects the first mark through interpolating computation using the outputs of the first light detector and the second light detector sampled by the sampling unit; and a velocity calculating unit that calculates a moving velocity of the moving body using the first time and the second time detected by the identical point detecting unit.
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14. An image forming apparatus comprising:
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a moving body; and a velocity detection apparatus comprising; a first light detector including a first emitter that illuminates optically identifiable marks disposed on a moving body, and a first light receiver that detects light from the optically identifiable marks; a second light detector including a second emitter that illuminates the optically identifiable marks and a second light receiver that detects light from the optically identifiable marks, wherein the second light detector is arranged at a predetermined interval from the first light detector in a moving direction of the moving body; a time-sharing light emitting unit that allows the first emitter and the second emitter to emit light in a time-sharing manner; an identical point detecting unit that detects a first time at which the first light detector detects a first mark among the optically identifiable marks, and a second time different from the first time at which the second light detector detects the first mark; and a velocity calculating unit that calculates a moving velocity of the moving body using the first time and the second time detected by the identical point detecting unit, wherein the time-sharing light emitting unit and the identical point detecting unit periodically performs; a first task that causes the first emitter to illuminate the optically identifiable marks; a second task that causes the first light receiver to detect light from the first light emitter via a predetermined point of the optically identifiable marks; a third task that causes the second emitter to illuminate the optically identifiable marks after turning off the first emitter after the first receiver detects light from the first light emitter; a fourth task that causes the second light receiver to detect light from the second light emitter via the predetermined point of the optically identifiable marks; and a fifth task that causes the second emitter to be turned off after the second light receiver detects light from the second emitter and then returns to the first task.
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Specification