Patent US3723641A successfully refreshed from Google Patents.
US3723641A
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Facsimile transmission method and apparatus
Assignee: Robert Bosch Elektronik GmbH
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Filing: 1971-03-31
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Granted: 1973-03-27
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Expires: 1991-03-31
Abstract
Abstract An improved facsimile transmission method and apparatus whereby the data to be transmitted may be transmitted in a shorter time than with conventional facsimile systems. The picture to be transmitted is scanned line-by-line with a conventional photoelectric scanner, but preferably at a speed such that the scanning frequency is greater than the maximum transmission frequency of the transmission channel, and the scanning voltage, which represents at least two different brightness values, preferably black and white, for a single line stored in a memory. The memory is then read out and the number of consecutive identical brightness value signals counted. Each time that the brightness value signal changes its value, e.g., from white to black or vice versa, the readout of the memory is interrupted, or temporarily delayed, until a pulse sequence representing the counted identical consecutive brightness signals and the brightness value has been formed and transmitted. This sequence of steps is repeated for each picture line to be transmitted.
Inventors
- 👤 F Heinrich
- 👤 D Prause
- 👤 R Sost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:43
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/41; H04N1/411; H04N1/413; H04N1/419
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
235 words
In a method of transmitting a picture from a first location to a second location via a transmission channel wherein the picture to be transmitted is photoelectrically scanned by a scanner moved in a line-by-line manner to produce a scanning voltage signal which is divided into at least two brightness value signals representing a black value and white value of the scanned picture elements and the scanning voltage is converted into binary code words derived by run length coding and representative of the brightness value signals for transmission, via the transmission channel, the improvement comprising: scanning a picture line at a relatively high constant speed to provide a scanning voltage representative of the brightness value signals of the picture elements of said picture line; storing the scanning voltage corresponding to a single picture line in a memory; following the storage of the scanning voltage, interrogating the memory to read out the stored scanning voltage at a higher speed than the scanning of the picture elemenTs and counting the number of consecutive identical brightness value signals; each time a change in the read-out scanning voltage, indicating a change in brightness value, is detected, interrupting the interrogation of the memory until a binary word representing the counted number of consecutive identical brightness value signals and the associated brightness value has been formed and transmitted; and repeating the above sequence of steps for each line of the picture.
Claim 2
Dependent Claim
235 words
In a method of transmitting a picture from a first location to a second location via a transmission channel wherein the picture to be transmitted is photoelectrically scanned by a scanner moved in a line-by-line manner to produce a scanning voltage signal which is divided into at least two brightness value signals representing a black value and white value of the scanned picture elements and the scanning voltage is converted into binary code words derived by run length coding and representative of the brightness value signals for transmission, via the transmission channel, the improvement comprising: scanning a picture line at a relatively high constant speed to provide a scanning voltage representative of the brightness value signals of the picture elements of said picture line; storing the scanning voltage corresponding to a single picture line in a memory; following the storage of the scanning voltage, interrogating the memory to read out the stored scanning voltage at a higher speed than the scanning of the picture elemenTs and counting the number of consecutive identical brightness value signals; each time a change in the read-out scanning voltage, indicating a change in brightness value, is detected, interrupting the interrogation of the memory until a binary word representing the counted number of consecutive identical brightness value signals and the associated brightness value has been formed and transmitted; and repeating the above sequence of steps for each line of the picture.
Claim 3
Dependent Claim
39 words
The method defined in claim 1 including the step of erasing the stored brightness value signals no later than after completion of the interrogation of all of the brightness values corresponding to one picture line stored in the memory.
Claim 4
Dependent Claim
63 words
The method defined in claim 1 wherein the speed of scanning the picture elements and the speed of interrogating the brightness values stored in the memory are so selected that the frequency corresponding to the number of picture elements scanned per unit time and the frequency of counting consecutive identical brightness values is higher than the maximum transmittable frequency of the transmission channel.
Claim 5
Dependent Claim
111 words
The method defined in claim 1 wherein two memories are utilized, each of which stores the scanning voltage signal of one of a pair of consecutive picture lines, and including the steps of: alternately interrogating the memories and transmitting said pulse sequence signals representative of the signals stored therein; and storing the scanning voltage signal from a picture line in one of said memories during the time required for the scanning voltage signal from the immediately preceding line to be read out of the other of the memories and transmitted as a pulse sequence, whereby the time lost between the transmission of signals corresponding to two consecutive picture lines is minimized.
Claim 6
Dependent Claim
49 words
The method defined in claim 4 wherein the time for storing a scanning voltage signal containing all of the brightness values from one picture line in a memory is shorter than the shortest time required for the transmission of the signals read out of a memory during interrogation thereof.
Claim 7
Dependent Claim
188 words
Facsimile apparatus for the transmission of a picture from a first location to a second distant location via a transmission channel, comprising, in combination: a photoelectric scanning means moved in a line-by-line pattern for scanning the picture at a relatively high constant speed per line and providing an output scanning voltage signal having at least two different voltage values representative of at least a black brightness value and a white brightness value respectively; a memory means for storing the scanning voltage representative of a single scanned line of the picture; circuit means for reading out the brightness value signals stored in said memory means at a higher speed than the scanning of the picture elements; and translation circuit means for counting the number of consecutive identical brightness value signals read from said memory and for temporarily interrupting the reading-out of the brightness value signals whenever a change in the brightness value signal is detected until such time as it has formed and transmitted binary code words derived by run length coding and representative of the number of identical brightness value signals which were counted and the brightness value.
Claim 8
Dependent Claim
188 words
Facsimile apparatus for the transmission of a picture from a first location to a second distant location via a transmission channel, comprising, in combination: a photoelectric scanning means moved in a line-by-line pattern for scanning the picture at a relatively high constant speed per line and providing an output scanning voltage signal having at least two different voltage values representative of at least a black brightness value and a white brightness value respectively; a memory means for storing the scanning voltage representative of a single scanned line of the picture; circuit means for reading out the brightness value signals stored in said memory means at a higher speed than the scanning of the picture elements; and translation circuit means for counting the number of consecutive identical brightness value signals read from said memory and for temporarily interrupting the reading-out of the brightness value signals whenever a change in the brightness value signal is detected until such time as it has formed and transmitted binary code words derived by run length coding and representative of the number of identical brightness value signals which were counted and the brightness value.
Claim 9
Dependent Claim
61 words
The facsimile apparatus defined in claim 6 including a clock pulse generator which furnishes a pulse-shaped voltage of constant frequency for controlling and synchronizing the time sequence of the storing and reading out of the brightness value signals from said memory, the counting of the interrogated brightness value signals by said translating circuit means, and the movement of said scanning means.
Claim 10
Dependent Claim
81 words
The facsimile apparatus defined in claim 6 wherein said memory means includes a pair of memories and wherein said apparatus includes means for alternately connecting the respective inputs and outputs of said memories to said scanning meaNs and said read-out means respectively so that the scanning voltage signal from one picture line is being read into one of said memories while the scanning voltage signal from the immediately preceding picture line is being read out of the other of said memories.
Claim 11
Dependent Claim
152 words
The facsimile apparatus defined in claim 6 wherein an interrogation circuit is connected in series between said scanning means and said memory means, sad interrogation circuit being responsive to a signal from said translation circuit means for connecting and disconnecting said scanning means and said memory means; wherein said read-out circuit means is responsive to an output signal from said translation circuit means, said read-out circuit means erasing the respective brightness value signals upon completion of its being read out; and wherein a clock pulse generator means is provided for directly controlling a drive means for moving said scanning means in the direction of a line and said translating circuit means, and for controlling, via control gates, the drive for the line shifting of said scanning means and the shifting of signals into and out of said memory, said control gates being further controlled by output signals from said translation circuit means.
Claim 12
Dependent Claim
199 words
The facsimile apparatus defined in claim 6 wherein said translating circuit means includes a first input connected via said read-out circuit means with the output of said memory means, a second input connected with the output of a clock pulse generator, a first output in communication with said transmission channel for providing output data signals, and four further outputs for providing control output signals, of which the first control output is connected to one input of said read-out circuit means, the second control output of said translating circuit means is connected to a first input of a clock pulse control circuit which has its second input connected to the output of said clock pulse generator and its output controlling the shifting of data in said memory means, the third control output of said translating circuit means is connected to one input of a control circuit for controlling the shift of said scanning means which control circuit has its other input connected to the output of said clock pulse generator, and the fourth control output of said translating circuit means is connected to one input of an interrogation circuit which is connected between said scanning means and said memory 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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |