Facsimile system with improved scanning

Claim 2

A facsimile system for producing a facsimile on facsimile paper from information in an input signal and with the facsimile produced on the facsimile paper by a plurality of write heads responsive to the information and with the write heads spaced around a closed drive band and with a portion of the drive band positioned adjacent to the facsimile paper to have the write heads alternately scanning across the facsimile paper and with the input signal including a periodically recurring sync signal, including: first means responsive to the periodically recurring sync signal in the input signal for producing a first position signal in accordance with the periodically recurring sync signal; second means responsive to the scanning of the write heads across the facsimile paper for producing a second position signal in accordance with the start of the scanning of each of the write heads across the facsimile paper, third means coupled to the first and second means and responsive to the first and second control signals for producing an error signal in accordance with the time difference between the periodically recurring sync system and the start of the scanning of each of the write heads on the band across the facsimile paper, and fourth means coupled to the drive band for controlling the speed of the drive band to control the speed of the scanning of the write heads across the facsimile paper and with the fourth means responsive to the error signal produced by the third means to vary the speed of the scanning of the write heads in accordance with the error signal to position the facsimile on the facsimile paper, and wherein the fourth means includes a constant frequency oscillator for producing a pulse signal of a constant frequency and wherein the fourth means includes means for adding or subtracting pulses from the pulse signal produced by the constant frequency oscillator and wherein the means included in the fourth means is responsive to the error signal produced by the third means to add or subtract pulses in accordance with the characteristics of the error signal.

Claim 3

The facsimile system of claim 1 wherein the facsimile paper is moved in a direction perpendicular to the path the write heads take in scanning across the facsimile paper and wherein the paper is moved using drive roller means on one side of the paper and a pair of pinch rollers on the other side of the paper at each end of the paper and wherein the rollers are located adjacent to the write heads and wherein the pair of pinch rollers are canted relative to the drive roller means to produce tension in the paper adjacent to the path the write heads take in scanning across the facsimile paper.

Claim 4

A facsimile system for producing a facsimile on facsimile paper from information in an input signal and with the facsimile produced on the facsimile paper by a closed drive band supporting a plurality of write heads responsive to the information and alternately scanning across the facsimile paper and with the information in the input signal having variations in frequency in representation of the facsimile, including: means responsive to the input signal for producing a variable amplitude signal in accordance with the variations in frequency of the input signal and including, capacitance means charging and discharging means responsive to the variations in frequency of the input signal for charging and discharging the capacitance means in accordance with the variations in frequency of the input signal to produce a charge level on the capacitance means having an amplitude in accordance with the charge level on the capacitance means, and meaNs coupled to the capacitance means and to the write heads for coupling the charge level on the capacitance means to the write heads to control the write heads.

Claim 5

A facsimile system for producing a facsimile on facsimile paper from information in an input signal and with the facsimile produced on the facsimile paper by a closed drive band supporting a plurality of write heads responsive to the information and alternately scanning across the facsimile paper and with the information in the input signal having variations in frequency in representation of the facsimile, including: means responsive to the input signal for producing a variable amplitude signal in accordance with the variations in frequency of the input signal and including, capacitance means charging and discharging means responsive to the variations in frequency of the input signal for charging and discharging the capacitance means in accordance with the variations in frequency of the input signal to produce a charge level on the capacitance means having an amplitude in accordance with the charge level on the capacitance means, and meaNs coupled to the capacitance means and to the write heads for coupling the charge level on the capacitance means to the write heads to control the write heads.

Claim 6

The facsimile system of claim 3 wherein the capacitance means includes a pair of capacitors and with one capacitor being alternately charged and discharged while the other capacitor is being alternately discharged and charged so that the pair of capacitors alternately sample the frequency of the information in the input signal.

Claim 7

The facsimile system of claim 3 wherein the capacitance means is charged from a fixed source of voltage and wherein the charging is interrupted at a frequency in accordance with the frequency of the information in the input signal and wherein the capacitance means is discharged at a frequency in accordance with the frequency of the information in the input signal.

Claim 8

The facsimile system of claim 3 wherein the charge level on the capacitance means is also coupled to a plurality of indicator means each responsive to different ranges of charge levels.

Claim 9

A facsimile system for producing a facsimile on facsimile paper from information in an input signal and with the facsimile produced on the facsimile paper by a drive band supporting a plurality of write heads responsive to the information and alternately scanning across the facsimile paper and with the input signal including a periodically recurring sync signal, including, first means responsive to the periodically recurring sync signal in the input signal for producing a first position signal in accordance with the periodically recurring sync signal, second means responsive to the scanning of each of the write heads across the facsimile paper for producing a second position signal in accordance with the start of the scanning of each of the write heads across the facsimile paper, third means coupled to the first and second means and responsive to the first and second control signals for producing an error signal in accordance with the time difference between the periodically recurring sync system and the start of the scanning of the write heads across the facsimile paper, fourth means for producing a constant frequency pulse output signal, and fifth means coupled to the third and fourth means and coupled to the write heads for producing a pulse drive signal to control the speed of the drive band to control the rate of scanning of the write heads and with the fifth means responsive to the constant frequency pulse output signal and the error signal to add or subtract pulses from the constant frequency pulse output signal in accordance with the error signal to produce the pulse drive signal.

Claim 10

A facsimile system for producing a facsimile on facsimile paper from information in an input signal and with the facsimile produced on the facsimile paper by a drive band supporting a plurality of write heads responsive to the information and alternately scanning across the facsimile paper and with the input signal including a periodically recurring sync signal, including, first means responsive to the periodically recurring sync signal in the input signal for producing a first position signal in accordance with the periodically recurring sync signal, second means responsive to the scanning of each of the write heads across the facsimile paper for producing a second position signal in accordance with the start of the scanning of each of the write heads across the facsimile paper, third means coupled to the first and second means and responsive to the first and second control signals for producing an error signal in accordance with the time difference between the periodically recurring sync system and the start of the scanning of the write heads across the facsimile paper, fourth means for producing a constant frequency pulse output signal, and fifth means coupled to the third and fourth means and coupled to the write heads for producing a pulse drive signal to control the speed of the drive band to control the rate of scanning of the write heads and with the fifth means responsive to the constant frequency pulse output signal and the error signal to add or subtract pulses from the constant frequency pulse output signal in accordance with the error signal to produce the pulse drive signal.

Claim 11

The facsimile system of claim 7 wherein the fifth means includes an adder-subtractor coupled between the fourth means and the write heads and a pair of pulsers coupled between the third means and the adder-subtractor.

Claim 12

The facsimile system of claim 7 wherein the periodically recurring sync signal occurs prior to the reception of the facsimile information and wherein the position of the facsimile is adjusted prior to the receiption of the facsimile information,

Claim 13

The facsimile system of claim 7 wherein the periodically recurring sync signal occurs prior to each line of facsimile information and wherein the position of the facsimile is adjusted continuously during the reception of the facsimile information.

Claim 14

A facsimile system for producing a facsimile on facsimile paper from information in an input signal having variations in frequency in representation of the facsimile and with the facsimile produced on the facsimile paper by a plurality of write heads responsive to the information and with the write heads spaced around a closed drive band and with a portion of the drive band positioned adjacent to the facsimile paper to have the write heads alternately scanning across the facsimile paper and with the input signal including a periodically recurring sync signal, including: FIRST means responsive to the periodically recurring sync signal in the input signal for producing a first position signal in accordance with the periodically recurring sync signal; second means responsive to the scanning of the write heads across the facsimile paper for producing a second position signal in accordance with the start of the scanning of each of the write heads across the facsimile paper, third means coupled to the first and second means and responsive to the first and second control signals for producing an error signal in accordance with the time difference between the periodically recurring sync system and the start of the scanning of each of the write heads on the band across the facsimile paper, and fourth means coupled to the drive band for controlling the speed of the drive band to control the speed of the scanning of the write heads across the facsimile paper and with the fourth means responsive to the error signal produced by the third means to vary the speed of the scanning of the write heads in accordance with the error signal to position the facsimile on the facsimile paper, and an automatic frequency selector responsive to the input signal to produce a variable amplitude signal in accordance with the variations in frequencies of the input signal and wherein the automatic frequency selector includes capacitance means alternately charged and discharged in accordance with the frequency of the input signal to produce a charge level on the capacitance means having an amplitude in accordance with the frequency of the input signal and with the charge level on the capacitance means coupled to the write heads in the facsimile system.

Claim 15

A facsimile system for producing a facsimile on facsimile paper from information in an input signal having variations in frequency in representation of the facsimile and with the facsimile produced on the facsimile paper by a plurality of write heads responsive to the information and with the write heads spaced around a closed drive band and with a portion of the drive band positioned adjacent to the facsimile paper to have the write heads alternately scanning across the facsimile paper and with the input signal including a periodically recurring sync signal, including: FIRST means responsive to the periodically recurring sync signal in the input signal for producing a first position signal in accordance with the periodically recurring sync signal; second means responsive to the scanning of the write heads across the facsimile paper for producing a second position signal in accordance with the start of the scanning of each of the write heads across the facsimile paper, third means coupled to the first and second means and responsive to the first and second control signals for producing an error signal in accordance with the time difference between the periodically recurring sync system and the start of the scanning of each of the write heads on the band across the facsimile paper, and fourth means coupled to the drive band for controlling the speed of the drive band to control the speed of the scanning of the write heads across the facsimile paper and with the fourth means responsive to the error signal produced by the third means to vary the speed of the scanning of the write heads in accordance with the error signal to position the facsimile on the facsimile paper, and an automatic frequency selector responsive to the input signal to produce a variable amplitude signal in accordance with the variations in frequencies of the input signal and wherein the automatic frequency selector includes capacitance means alternately charged and discharged in accordance with the frequency of the input signal to produce a charge level on the capacitance means having an amplitude in accordance with the frequency of the input signal and with the charge level on the capacitance means coupled to the write heads in the facsimile system.