US4398221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Facsimile apparatus
Assignee: Ricoh Co Ltd
•
Filing: 1981-08-25
•
Granted: 1983-08-09
•
Expires: 2001-08-25
Abstract
Abstract A horizontal scan sync signal is generated at every predetermined time interval allowing for a time period necessary for one line of video data to be stored in a RAM. In response to the horizontal scan sync signal, a video signal is transferred in parallel to a shift register inside a solid scanning element. When a microprocessor or CPU has failed to take in video data within a predetermined period of time after the appearance of the horizontal scan sync signal, shift clock pulses are forcibly generated so that a video signal is coupled from the solid scanning element to a binary circuit. The interval between successive horizontal sync signals, in response to which the CPU takes in each line of video data, may be made relatively short to schedule artificial periods in which the CPU does not take in any video data. By utilizing such a specific period, the components of a video signal output of the solid scanning element which appear within a given period can be processed to prepare a threshold value.
Inventors
- 👤 Shingo Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:48
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/41; H04N1/411; H04N1/413
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
216 words
A facsimile apparatus having a random access memory and a microprocessor for encoding data from the random access memory, comprising: scanner means for producing a serial image or video data output; binary circuit means for producing a serial binary video data output from the serial video data output of the scanner means; serial to parallel converter means for converting the serial binary video data output to a parallel binary video data output, the microprocessor being constructed to produce a read strobe when the parallel binary video data output can be inputted to the random access memory after encoding the previous data from the random access memory; sync signal generator means for producing a sync signal at a predetermined interval, the microprocessor being constructed to produce the read strobe in response to the sync signal; shift clock pulse generator means for producing shift clock pulses in response to the read strobe from the microprocessor, the scanner being constructed to feed the serial video data output to the binary circuit means in response to the shift clock pulses; and control means for controlling the shift clock pulse generator to forcibly produce the shift clock pulses which are fed to the scanner means whether or not the parallel binary data output can be inputted to the random access memory.
Claim 2
Dependent Claim
216 words
A facsimile apparatus having a random access memory and a microprocessor for encoding data from the random access memory, comprising: scanner means for producing a serial image or video data output; binary circuit means for producing a serial binary video data output from the serial video data output of the scanner means; serial to parallel converter means for converting the serial binary video data output to a parallel binary video data output, the microprocessor being constructed to produce a read strobe when the parallel binary video data output can be inputted to the random access memory after encoding the previous data from the random access memory; sync signal generator means for producing a sync signal at a predetermined interval, the microprocessor being constructed to produce the read strobe in response to the sync signal; shift clock pulse generator means for producing shift clock pulses in response to the read strobe from the microprocessor, the scanner being constructed to feed the serial video data output to the binary circuit means in response to the shift clock pulses; and control means for controlling the shift clock pulse generator to forcibly produce the shift clock pulses which are fed to the scanner means whether or not the parallel binary data output can be inputted to the random access memory.
Claim 3
Dependent Claim
35 words
A facsimile apparatus as claimed in claim 1, in which the scanner means comprises a shift register responsive to the shift clock pulses to feed the serial video data output to the binary circuit means.
Claim 4
Dependent Claim
23 words
A facsimile apparatus as claimed in claim 1, in which the binary circuit means comprises a peak value holding circuit and a comparator.
Claim 5
Dependent Claim
62 words
A facsimile apparatus as claimed in claim 1, in which the serial to parallel converter means comprises a serial to parallel converter register responsive to the serial binary video data output to convert the same to the parallel binary video data output, and a tri-state buffer responsive to the read strobe to feed the parallel binary video data output to the microprocessor.
Claim 6
Dependent Claim
49 words
A facsimile apparatus as claimed in claim 1, in which the sync signal generator means comprises a timing pulse counter for counting clock pulses, and gate circuit means responsive to outputs of the timing pulse counter and the clock pulses to produce the sync signal at the predetermined interval.
Claim 7
Dependent Claim
23 words
A facsimile apparatus as claimed in claim 5, in which the gate circuit means comprises an AND gate and a line sync flag.
Claim 8
Dependent Claim
52 words
A facsimile apparatus as claimed in claim 1, in which the shift clock pulse generator means comprises a read strobe latch responsive to the read strobe from the microprocessor to produce an output, and gate circuit means responsive to the output of the read strobe latch to produce the shift clock pulses.
Claim 9
Dependent Claim
59 words
A facsimile apparatus as claimed in claim 7, in which the shift clock pulse generator means further comprises a counter for counting the shift clock pulses to produce an output which is fed to the gate circuit means when the count in the counter reaches a predetermined value, whereby the gate circuit means stops producing the shift clock pulses.
Claim 10
Dependent Claim
81 words
A facsimile apparatus as claimed in claim 6, in which the control means comprises a read strobe latch which is reset by an output of the line sync flag of the sync signal generator means, and a free run mode flag which is set by an output of the timing pulse counter of the sync signal generator means to produce an output which is fed to the shift clock pulse generator means which then produces the shift clock pulses in succession.
Claim 11
Dependent Claim
125 words
A facsimile apparatus as claimed in claim 3, in which the binary circuit means further comprises an analog switch connected between the scanner means and the peak value holding circuit for inhibiting the serial video data output from being fed from the scanner means to the peak value holding circuit at an interval which is shorter than the predetermined interval at which the sync signal is produced, and a control drive circuit for controllably driving the analog switch, said control drive circuit comprising a gate unit responsive to selected outputs of the timing pulse counter and an AND gate responsive to an output of the gate unit and an output of the control means to produce an output by which the analog switch is closed.
Claim 12
Dependent Claim
59 words
A facsimile apparatus as claimed in claim 1, further comprising a modem, a scanning speed of the scanner means being set to a speed which is greater than a data transmission speed of the modem to thereby decrease the number of times of producing the read strobe from the microprocessor when the sync signal is fed to the microprocessors.
Claim 13
Dependent Claim
179 words
A facsimile apparatus including scanner means for producing serial analog video signals in response to shift pulses, shift pulse generator means for producing the shift pulses, binary circuit means for converting the analog video signals into binary video signals and computing means for operating on the binary video signals in a predetermined manner, characterized by comprising: sync signal generator means for generating and feeding a sync signal to the scanner means and the computing means, the computing means being constructed to generate a read strobe in response to the sync signal only if the computing means is in a condition to operate on the binary video signals; and control means for gating a predetermined number of shift pulses from the shift pulse generator means to the scanner means in response to the read stroke, the control means being further constructed to continuously gate shift pulses from the shift pulse generator means to the scanner means when a predetermined period of time has elapsed after generation of the sync signal and the computing means has not generated the read strobe.
Claim 14
Dependent Claim
179 words
A facsimile apparatus including scanner means for producing serial analog video signals in response to shift pulses, shift pulse generator means for producing the shift pulses, binary circuit means for converting the analog video signals into binary video signals and computing means for operating on the binary video signals in a predetermined manner, characterized by comprising: sync signal generator means for generating and feeding a sync signal to the scanner means and the computing means, the computing means being constructed to generate a read strobe in response to the sync signal only if the computing means is in a condition to operate on the binary video signals; and control means for gating a predetermined number of shift pulses from the shift pulse generator means to the scanner means in response to the read stroke, the control means being further constructed to continuously gate shift pulses from the shift pulse generator means to the scanner means when a predetermined period of time has elapsed after generation of the sync signal and the computing means has not generated the read strobe.
Claim 15
Dependent Claim
18 words
A facsimile apparatus as in claim 12, in which the binary circuit means comprises peak hold circuit means.
Claim 16
Dependent Claim
61 words
A facsimile apparatus as in claim 13, further comprising switch means, the control means being further constructed to control the switch means to prevent the analog video signals from being input to the peak hold circuit means for predetermined length of time in response to continuous gating of the shift pulses from the shift pulse generator means to the scanner means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |