Method and apparatus for time compression of facsimile transmissions

Claim 2

A facsimile transmitter for transmitting signals to a remote location representing dark-light variations in a document at said transmitter, said transmitter comprising: optical sensor means in optical communication with said document; signal generating means coupled and responsive to said optical sensor means for generating video signals representing light and dark regions on said document; signal transmitting means coupled to said signal generating means for generating transmission signals from said video signals representing the sensing of said light and dark regions on said document; scanning means for moving said optical sensor means relative to said document at a slow scanning rate and a fast scanning rate; and scanning rate control means including timing means coupled to said signal generating means and said scanning means for automatically initiating said fast scanning rate when the timed period between signals representing dark regions on said document as determined by said timing means exceeds a predetermined period and automatically reinstating said slow scanning rate when said optical sensor means senses a dark region, said timing means being reset by said video signals representing dark regions.

Claim 3

The facsimile transmitter of claim 1 wherein said timing means comprises RC circuitry charging and discharging in response to signals representing dark and light regions generated by said signal generating means.

Claim 4

The facsimile transmitter of claim 1 comprising clamping means coupled to the output of said optical sensor means so as to obtain a substantially uniform response to all dark signals and a substantially uniform response to all light signals by said signal transmitting means and said scanning rate control means.

Claim 5

The facsimile transmitter of claim 1 wherein said timing means comprises detector means for detecting the sensing of a dark region on said document within a time frame, said signal transmitting means being coupled to said detector means so as to generate a transmission signal after said time frame representing the sensing of a dark region within said time frame.

Claim 6

The facsimile transmitter of claim 4 further comprising clock means coupled to said detector means for generating a series of clock pulses in synchronism with the scanning of said document, the period between clock pulses in said series representing said time frame.

Claim 7

The facsimile transmitter of claim 4 wherein said timing means further comprises RC timing circuitry coupled to said detector means, said RC circuitry charging and discharging in response to signals representing dark and light regions generated by said signal generating means such that the state of charge or discharge of said RC circuitry represents the sensing or lack of sensing of a dark region in said time frame.

Claim 8

The facsimile transmitter of claim 4 wherein said timing means further comprises a timer coupled to said detector means and automatically reset at the end of said time frame in response to the sensing of a dark region of said document during said time frame, said timer automatically initiating a fast scanning rate at the end of the next time frame in the absence of a dark region sensed in said time frame and automatically delaying the initiation of the fast scanning rate at last until the end of the next time frame in the presence of a dark region sensed during said time frame.

Claim 9

The facsimile transmitter of claim 7 wherein said time frame corresponds to a predetermined scanning distance of said scanning means relative to said optical sensor means.

Claim 10

The facsimile transmitter of claim 8 wherein said scanning means comprises a rotatable drum and said scanning distance corresponds to one revolution of said drum.

Claim 11

The facsimile transmitter of claim 1 wherein said optical sensor means comprises a read optical pickup means and a lead optical pickup means, said lead optical pickup means being positioned relative to said read optical pickup means so as to scan said document in advance of said read optical pickup means.

Claim 12

The facsimile transmitter of claim 10 wherein said read optical pickup means comprises read fiber optic means and said lead optical pickup means comprises lead fiber optic means, said read fiber optic means and said lead fiber optic means being in direct optical communication with said document.

Claim 13

The facsimile transmitter of claim 10 wherein said lead optical pickup means is coupled to said scanning control means so as to automatically reinstate said slow scanning rate when said lead optical pickup means generates a signal representing a dark region.

Claim 14

A facsimile receiver for receiving signals from a remote location representing dark-light variations in a document at said remote location, said receiver comprising: writing means for marking on a copy medium; signal receiving means coupled to said writing means for generating writing control signals for actuating said writing means so as to mark said copy medium when signals representing dark regions are received; scanning means for moving said writing means relative to said copy medium at a slow scanning rate and a fast scanning rate; scanning rate control means including timing means coupled to said signal receiving means and said scanning means for automatically initiating said fast scanning rate in response to and after a predetermined time lapse between writing control signals representing dark regions as determined by said timing means, said scanning rate control means automatically reinstating said slow scanning rate in response to a writing control signal representing a dark region, each writing control signal representing a dark region resetting said timing means.

Claim 15

A facsimile receiver for receiving signals from a remote location representing dark-light variations in a document at said remote location, said receiver comprising: writing means for marking on a copy medium; signal receiving means coupled to said writing means for generating writing control signals for actuating said writing means so as to mark said copy medium when signals representing dark regions are received; scanning means for moving said writing means relative to said copy medium at a slow scanning rate and a fast scanning rate; scanning rate control means including timing means coupled to said signal receiving means and said scanning means for automatically initiating said fast scanning rate in response to and after a predetermined time lapse between writing control signals representing dark regions as determined by said timing means, said scanning rate control means automatically reinstating said slow scanning rate in response to a writing control signal representing a dark region, each writing control signal representing a dark region resetting said timing means.

Claim 16

The facsimile receiver of claim 13 wherein timing means is automatically reset in response to a writing control signal representing a dark region.

Claim 17

The facsimile receiver of claim 14 wherein said timing means comprises RC circuitry charging and discharging in response to writing control signals representing dark and light regions.

Claim 18

A facsimile transmitter for transmitting signals to a remote location representing dark-light variations in a document at said transmitter, said transmitter comprising: a drum for carrying a document including clamping means for holding said document in place on said drum; fiber optic sensor means in optical communication with said document for generating signals representing light and dark regions on said document; signal transmitting means coupled to said sensor means for generating transmission signals representing the sensing of light and dark regions on said document; scanning means for moving said fiber optic sensor means relative to said document at a slow scanning rate and a fast scanning rate; scanning rate control means coupled to said fiber optic sensor means and said scanning means for automatically initiating said fast scanning rate when the distance between dark regions on said document exceeds said predetermined distance as sensed by said fiber optic sensor means and automatically reinstating said slow scanning rate when said fiber optic sensor means senses a dark region; said signal transmitting means generating a transmission signal representing the sensing of a light region for a period of time corresponding to the time elapsed in scanning said predetermined distance as sensed by said fiber optic sensor means, said signal transmitting means continuing to generate a transmission signal representing the sensing of a light region during initiation of said fast scanning rate and thereafter until said optical sensor means senses a dark region whereupon said scanning rate control means reinstates said slow scanning rate; said scanning rate control means including blanking means coupled to said scanning means for generating a blanking signal in synchronism with the passage of said clamping means past said fiber optic sensor means so as to permit said continuing generation of said transmission signal representing the sensing of said light regions while said scanning means is scanning said fiber optic means past said clamping means.

Claim 19

A facsimile transmitter for transmitting signals to a remote location representing dark-light variations in a document at said transmitter, said transmitter comprising: a drum for carrying a document including clamping means for holding said document in place on said drum; fiber optic sensor means in optical communication with said document for generating signals representing light and dark regions on said document; signal transmitting means coupled to said sensor means for generating transmission signals representing the sensing of light and dark regions on said document; scanning means for moving said fiber optic sensor means relative to said document at a slow scanning rate and a fast scanning rate; scanning rate control means coupled to said fiber optic sensor means and said scanning means for automatically initiating said fast scanning rate when the distance between dark regions on said document exceeds said predetermined distance as sensed by said fiber optic sensor means and automatically reinstating said slow scanning rate when said fiber optic sensor means senses a dark region; said signal transmitting means generating a transmission signal representing the sensing of a light region for a period of time corresponding to the time elapsed in scanning said predetermined distance as sensed by said fiber optic sensor means, said signal transmitting means continuing to generate a transmission signal representing the sensing of a light region during initiation of said fast scanning rate and thereafter until said optical sensor means senses a dark region whereupon said scanning rate control means reinstates said slow scanning rate; said scanning rate control means including blanking means coupled to said scanning means for generating a blanking signal in synchronism with the passage of said clamping means past said fiber optic sensor means so as to permit said continuing generation of said transmission signal representing the sensing of said light regions while said scanning means is scanning said fiber optic means past said clamping means.

Claim 20

The facsimile transmitter of claim 16 wherein said blanking signals are separated in time by said period of time corresponding to the time elapsed in scanning said predetermined distance.

Claim 21

The facsimile transmitter of claim 16 wherein said scanning rate control means comprises timing means for determining said period of time and means for automatically resetting said timing means in response to the sensing of a dark region on said document between said blanking signal and the previous blanking signal.

Claim 22

The facsimile transmitter of claim 18 wherein said scanning rate control means is coupled to said signal transmitting means so as to generate a transmission signal representing a dark region substantially simultaneously with said blanking signal when a dark region has been sensed in the period between said blanking signal and the previous blanking signal.

Claim 23

A facsimile system for producing a copy at one location which is a facsimile of a document located at another location comprising: a transmitter including optical sensor means for detecting light and dark regions on an information-bearing document; signal transmitting means coupled to said sensor means for generating signals representing the detection of said light and dark regions, transmitter scanning means for moving said document relative to said sensor means at a slow scanning rate and a fast scanning rate, and transmitter scanning rate control means coupled to said optical sensor means and said scanning means for automatically initiating said fast scanning rate when the distance between said dark regions on said document exceeds a predetermined distance as sensed by said optical sensor means and automatically reinstating said slow scanning rate when said optical sensor means senses a dark region, said signal transmitting means generating a transmission signal representing the sensing of a light region for a period of time corresponding to the time elapsed in scanning said predetermined distance as sensed by said optical sensor means, said signal transmitting means continuing to generate a transmission signal representing the sensing of a light region during initiation of said fast scanning rate and thereafter until said optical sensor means senses a dark region whereupon said scanning rate control means reinstates said slow scanning rate; a communication network coupled to the transmitter for transmitting said signals representing the detection of said light and dark regions; and a receiver including writing means for marking a copy medium, signal receiving means coupled to said writing means for generating writing control signals for demodulating said signals representing said light and dark regions and actuating said writing means to mark said copy medium when signals representing said dark regions are received, receiver scanning means for moving said document relative to said writing means at a slow scanning rate and a fast scanning rate, and receiver scanning control means including timing means coupled to said signal receiving means and said receiver scanning means for automatically initiating said fast scanning rate for said receiver scanning means in response to and after a time lapse as determined by said timing means between writing control signals representing dark regions, said time lapse corresponding to the time elapsed in scanning said predetermined distance at said transmitter, said receiver scanning rate control means automatically reinstating said slow scanning rate in response to a writing control signal representing a dark region, said timing means being reset by said writing control signal representing a dark region.

Claim 24

A facsimile system for producing a copy at one location which is a facsimile of a document located at another location comprising: a transmitter including optical sensor means for detecting light and dark regions on an information-bearing document; signal transmitting means coupled to said sensor means for generating signals representing the detection of said light and dark regions, transmitter scanning means for moving said document relative to said sensor means at a slow scanning rate and a fast scanning rate, and transmitter scanning rate control means coupled to said optical sensor means and said scanning means for automatically initiating said fast scanning rate when the distance between said dark regions on said document exceeds a predetermined distance as sensed by said optical sensor means and automatically reinstating said slow scanning rate when said optical sensor means senses a dark region, said signal transmitting means generating a transmission signal representing the sensing of a light region for a period of time corresponding to the time elapsed in scanning said predetermined distance as sensed by said optical sensor means, said signal transmitting means continuing to generate a transmission signal representing the sensing of a light region during initiation of said fast scanning rate and thereafter until said optical sensor means senses a dark region whereupon said scanning rate control means reinstates said slow scanning rate; a communication network coupled to the transmitter for transmitting said signals representing the detection of said light and dark regions; and a receiver including writing means for marking a copy medium, signal receiving means coupled to said writing means for generating writing control signals for demodulating said signals representing said light and dark regions and actuating said writing means to mark said copy medium when signals representing said dark regions are received, receiver scanning means for moving said document relative to said writing means at a slow scanning rate and a fast scanning rate, and receiver scanning control means including timing means coupled to said signal receiving means and said receiver scanning means for automatically initiating said fast scanning rate for said receiver scanning means in response to and after a time lapse as determined by said timing means between writing control signals representing dark regions, said time lapse corresponding to the time elapsed in scanning said predetermined distance at said transmitter, said receiver scanning rate control means automatically reinstating said slow scanning rate in response to a writing control signal representing a dark region, said timing means being reset by said writing control signal representing a dark region.

Claim 25

A facsimile transceiver for transmitting signals or receiving signals representing dark-light variations in a document, said transceiver comprising: optical sensor means in optical communication with said document for generating sensor signals representing light and dark regions on said document; signal transmitting means coupled to said sensor means for generating transmission signals representing the sensing of said light and dark regions on said document; writing means adapted to be placed in writing communication with a copy medium; signal receiving means for generating writing control signals representing the sensing of said light and dark regions on said document at a remote transmitter; scanning means moving said optical sensor means relative to said document or said copy medium at a slow scanning rate and a fast scanning rate; and scanning rate control means including timing means coupled to said optical sensor means and said signal receiving means, said scanning rate control means automatically initiating said fast scanning rate in response to the timed separation in sensor signals generated by said optical sensor means or writing control signals generated by said receiving means representing a light region of predetermined size as determined by said timing means and automatically reinstating said slow scanning rate in response to sensor signals generated by said optical sensor means or writing control signals generated by said signal receiving means representing the sensing of a dark region after said light region of predetermined size.

Claim 26

A facsimile transceiver for transmitting signals or receiving signals representing dark-light variations in a document, said transceiver comprising: optical sensor means in optical communication with said document for generating sensor signals representing light and dark regions on said document; signal transmitting means coupled to said sensor means for generating transmission signals representing the sensing of said light and dark regions on said document; writing means adapted to be placed in writing communication with a copy medium; signal receiving means for generating writing control signals representing the sensing of said light and dark regions on said document at a remote transmitter; scanning means moving said optical sensor means relative to said document or said copy medium at a slow scanning rate and a fast scanning rate; and scanning rate control means including timing means coupled to said optical sensor means and said signal receiving means, said scanning rate control means automatically initiating said fast scanning rate in response to the timed separation in sensor signals generated by said optical sensor means or writing control signals generated by said receiving means representing a light region of predetermined size as determined by said timing means and automatically reinstating said slow scanning rate in response to sensor signals generated by said optical sensor means or writing control signals generated by said signal receiving means representing the sensing of a dark region after said light region of predetermined size.

Claim 27

The facsimile transceiver of claim 21 wherein said timing means comprises detector means for detecting the sensing of a dark region on said document within a time frame, said signal transmitting means being coupled to said detector means so as to generate a writing control signal after said time frame representing the sensing of a dark region within said time frame.

Claim 28

The facsimile transceiver of claim 22 further comprising clock means coupled to said detector means for generating a series of clock pulses in synchronism with the scanning of said document, the period between clock pulses in said series representing said time frame.

Claim 29

The facsimile transceiver of claim 22 wherein said scanning control means further comprises additional timing means coupled to said detector means and automatically reset at the end of said time frame in response to the sensing of a dark region on said document and the generation of said sensor signal during said time frame, said additional timing means automatically initiating a fast scanning rate at the end of said time frame in the absence of a dark region sensed in said time frame and automatically delaying the initiation of the fast scanning rate at least until the end of the next time frame in the presence of a dark region sensed during said time frame.

Claim 30

The facsimile transceiver of claim 24 wherein said additional timing means is also coupled to said signal receiving means so as to automatically reset said additional timing means at the end of said time frame in response to the generation of a writing control signal representing the dark region on said document during said time frame, said additional timing means automatically initiating a fast scanning rate at the end of the next time frame in the absence of a received signal representing the sensing of a dark region in said time frame and automatically delaying the initiation of the fast scanning rate at least until the end of the next time frame in response to the generation of a writing control signal representing a sensed dark region during said time frame.

Claim 31

In a facsimile system comprising a transmitter including optical sensor means in optical communication with said document, signal transmitting means coupled to said sensor means and scanning means for moving said optical sensor means relative to said document in a slow scanning rate or a fast scanning rate, and a receiver including writing means for marking on a copy medum, signal receiving means for actuating said writing means so as to mark in said copy medium when signals representing dark regions are received and scanning means for moving said writing means relative to said copy medium at a slow scanning rate and a fast scanning rate, a method of operation comprising the following steps: sensing light and dark regions on said document with said sensor means; transmitting signals representing light and dark regions as sensed by said optical sensor means; automatically initiating the fast scanning rate at the transmitter when the time lapse between the sensing of dark regions exceeds a predetermined limit; continually transmitting signals representing light and dark regions while scanning at the fast scanning rate; receiving signals representing light and dark regions; forming dark regions on a copy medium in response to received signals representing said dark regions; timing the lapse between said received signals representing said dark regions; and automatically initiating said fast scanning rate at the receiver when the time lapse between said received signals exceeds said predetermined limit.

Claim 32

In a facsimile system comprising a transmitter including optical sensor means in optical communication with said document, signal transmitting means coupled to said sensor means and scanning means for moving said optical sensor means relative to said document in a slow scanning rate or a fast scanning rate, and a receiver including writing means for marking on a copy medum, signal receiving means for actuating said writing means so as to mark in said copy medium when signals representing dark regions are received and scanning means for moving said writing means relative to said copy medium at a slow scanning rate and a fast scanning rate, a method of operation comprising the following steps: sensing light and dark regions on said document with said sensor means; transmitting signals representing light and dark regions as sensed by said optical sensor means; automatically initiating the fast scanning rate at the transmitter when the time lapse between the sensing of dark regions exceeds a predetermined limit; continually transmitting signals representing light and dark regions while scanning at the fast scanning rate; receiving signals representing light and dark regions; forming dark regions on a copy medium in response to received signals representing said dark regions; timing the lapse between said received signals representing said dark regions; and automatically initiating said fast scanning rate at the receiver when the time lapse between said received signals exceeds said predetermined limit.

Claim 33

The method of claim 26 including the step of automatically reinitiating the slow scanning rate at said transmitter when a dark region is sensed and automatically reinstating the slow scanning rate at the receiver when a signal representing a dark region is received.

Claim 34

The method of claim 26 wherein the fast scanning rate at the transmitter is automatically initiated in the absence of sensing a dark region in the predetermined time frame.

Claim 35

The method of claim 26 including the steps of: automatically reinstating said slow scanning rate at the transmitter at the end of a time frame in which the dark region is sensed; transmitting signals representing the sensing of light regions until the end of said time frame in which said dark region is sensed, and automatically reinstating said slow scanning rate at the receiver at the end of a time frame in which a signal representing a dark region is received.

Claim 36

A facsimile receiver for receiving signals representing dark-light variations in a document at a remote location, said receiver comprising: writing means for marking a copy medium; signal receiving means coupled to said writing means for generating writing control signals for actuating said writing.

Claim 37

A facsimile receiver for receiving signals representing dark-light variations in a document at a remote location, said receiver comprising: writing means for marking a copy medium; signal receiving means coupled to said writing means for generating writing control signals for actuating said writing.

Claim 38

The facsimile receiver of claim 30 comprising timing means automatically reset in response to a writing control signal representing a dark region, said timing means automatically initiating a fast scanning rate at the end of a timing period in the absence of a writing control signal representing a dark region during said timing period and automatically delaying the initiation of the fast scanning rate at least until the end of the next timing period when a writing control signal representing a dark region is sensed during the previous timing period.

Claim 39

A facsimile transmitter for transmitting signals representing dark and light regions on a document at the transmitter, said transmitter comprising: sensor means for sensing dark and light regions on the document; scanning means for moving said sensor means relative to said document at a fast scanning rate and a slow scanning rate; transmitting means coupled to said sensor means for generating information signals representing each dark region on the document sensed by the sensor means during a time frame corresponding to a predetermined scanning distance and a video signal representing a dark region at the end of said time frame when a dark region has been sensed during said time frame; and scanning rate control means responsive to said video signals for initiating a fast scanning rate in the absence of a sensed dark region during said time frame and a slow scanning rate in the presence of a sensed dark region during said time frame.

Claim 40

A facsimile transmitter for transmitting signals representing dark and light regions on a document at the transmitter, said transmitter comprising: sensor means for sensing dark and light regions on the document; scanning means for moving said sensor means relative to said document at a fast scanning rate and a slow scanning rate; transmitting means coupled to said sensor means for generating information signals representing each dark region on the document sensed by the sensor means during a time frame corresponding to a predetermined scanning distance and a video signal representing a dark region at the end of said time frame when a dark region has been sensed during said time frame; and scanning rate control means responsive to said video signals for initiating a fast scanning rate in the absence of a sensed dark region during said time frame and a slow scanning rate in the presence of a sensed dark region during said time frame.

Claim 41

The facsimile transmitter of claim 32 wherein said scanning rate control means comprises timing means reset by said video signals.

Claim 42

The facsimile transmitter of claim 32 wherein said time frame corresponds to a predetermined scanning distance of said scanning means relative to said sensor means.

Claim 43

The facsimile transmitter of claim 34 wherein said scanning means comprises a rotatable drum and said scanning distance corresponds to one revolution of said drum.