Back to results
US 6,724,381 B2Granted
Signal processing apparatus for generating clocks phase-synchronized with input signal
AssigneeCanon Kabushiki Kaisha
InventorYukihiko Sakashita
Life of this patent
Estimating the term…
Abstract
An image signal processing apparatus has a clock generation circuit for generating a clock which is phase-synchronized with an input image signal, a sampling circuit for sampling the input image signal in response to the clock, a comparator circuit for comparing a plurality of samples output from the sampling circuit with each other, and a control circuit for controlling a phase of the clock by controlling the clock generating circuit in accordance with a comparison result by the compartor circuit.
Claims26
An image signal processing apparatus, comprising:
- clock generating means for generating a clock which is phase-synchronized with an input image signal;
- sampling means for sampling the input image signal in response to the clock;
- selecting means for selecting a sample having a value larger than adjacent samples from a plurality of samples output from said sampling means;
- comparison means for comparing a plurality of selected samples selected by said selecting means with each other;
- and
- control means for detecting a maximum value of the plurality of selected samples in accordance with a comparison result of said comparison means, and for controlling said clock generating means to adjust a phase of the clock in accordance with the detection result of the maximum value.
3 more elements
An image signal processing apparatus, comprising:
- clock generating means for generating a clock which is phase-synchronized with an input image signal;
- sampling means for sampling the input image signal in response to the clock;
- mode switching means for switching a mode of said apparatus among a plurality of modes including a first mode wherein said clock generating means generates a first clock having a first phase and said sampling means samples the input image signal in response to the first clock, and a second mode wherein said clock generating means generates a second clock having a second phase different from the first phase and said sampling means samples the input image signal in response to the second clock;
- selecting means for selecting a sample having a value larger than adjacent samples from a plurality of samples output from said sampling means;
- and
- control means for adjusting a phase of the clock generated by said clock generating means in accordance with (i) a maximum value of the selected samples selected by said selecting means from the plurality of samples obtained in the first mode, and (ii) a maximum value of the selected samples selected by said selecting means from the plurality of samples obtained in the second mode.
3 more elements
An image signal processing apparatus, comprising:
- clock generating means for generating a clock which is phase-synchronized with an input image signal;
- sampling means for sampling the input image signal in response to the clock;
- mode switching means for switching a mode of said apparatus among a plurality of modes wherein said clock generating means generates a plurality of clocks having phases different from each other by a predetermined amount;
- selecting means for selecting a sample having a value larger than adjacent samples from a plurality of samples output from said sampling means;
- and
- control means for detecting, in each of the plurality of modes, a maximum value of the samples selected by said selecting means from the plurality of samples, and for adjusting a phase of the clock generated by said clock generating means in accordance with the maximum values detected in the plurality of modes.
3 more elements
An image signal processing method, comprising the steps of:
- generating a clock which is phase-synchronized with an input image signal;
- sampling the input image signal in response to the clock;
- selecting a sample having a value larger than adjacent samples from a plurality of samples output in said sampling step;
- comparing a plurality of selected samples selected in said sample selecting step with each other;
- and
- detecting a maximum value of the plurality of selected samples in accordance with a comparison result obtained in said detecting sample comparison steps, and controlling said clock generating step to adjust a phase of the clock in accordance with the detection result of the maximum value.
3 more elements
An image signal processing method comprising the steps of:
- generating a clock which is phase-synchronized with an input image signal;
- sampling the input image signal in response to the clock;
- switching a mode of said apparatus among a plurality of modes including a first mode wherein said clock generating step generates a first clock having a first phase and said sampling step samples the input image signal in response to the first clock, and a second mode wherein said clock generating step generates a second clock having a second phase different from the first phase and said sampling step samples the input image signal in response to the second clock;
- selecting a sample having a value larger than adjacent samples from a plurality of samples output in said sampling step;
- and
- adjusting a phase of the clock generated in said clock generating step in accordance with (i) a maximum value of the selected samples selected in said selecting step from the plurality of samples obtained in the first mode, and (ii) a maximum value of the selected samples selected in said selecting step from the plurality of samples obtained in the second mode.
3 more elements
A computer readable storage medium storing program codes for realizing an image signal processing method, the program codes comprising the steps of:
- generating a clock which is phase-synchronized with an input image signal;
- sampling the input image signal in response to the clock;
- selecting a sample having a value larger than adjacent samples from a plurality of samples output in said sampling step;
- comparing a plurality of selected samples selected in said sample selecting step, with each other;
- and
- detecting a maximum value of the plurality of selected samples in accordance with a comparison result obtained in said detecting samples comparison step, and controlling said clock generating step to adjust a phase of the clock in accordance with the detection result of the maximum value.
3 more elements
A computer readable storage medium storing program codes for realizing an image signal processing method, the program codes comprising the steps of:
- generating a clock which is phase-synchronized with an input image signal;
- sampling the input image signal in response to the clock;
- switching a mode of said apparatus among a plurality of modes including a first mode wherein said clock generating step generates a first clock having a first phase and said sampling step samples the input image signal in response to the first clock, and a second mode wherein said clock generating step generates a second clock having a second phase different from the first phase and said sampling step samples the input image signal in response to the second clock;
- selecting a sample having a value larger than adjacent samples from a plurality of samples output in said sampling step;
- and
- adjusting a phase of the clock generated in said clock generating step in accordance with (i) a maximum value of the selected samples selected in said selecting step from the plurality of samples obtained in the first mode and (ii) a maximum value of the selected samples selected in said selecting step from the plurality of samples obtained in the second mode.
3 more elements
Dependencies are inferred from the claim text.