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US 4,186,415 AGranted
Facsimile compression system
AssigneeOki Electric Industry Co., Ltd.
InventorShoichiro Takayama
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AssigneeOki Electric Industry Co., Ltd.
InventorShoichiro Takayama
Estimating the term…
A facsimile signal is compressed by skipping the continuous white cells longer than a predetermined length, and the compressed facsimile signal is transmitted in an analog form. When some portion of a facsimile signal is deleted due to the absence of a black cell in said portion, an f-signal indicating the deletion of said portion is inserted at the head of the deleted portion. The amplitude of the f-signal is twice as high as the highest level of a picture signal thus a reception station can differentiate the f-signal from a picture signal. The compressed facsimile signal is modulated to an AM.PM.VSB signal (Amplitude Modulation-Phase Modulation-Vestigial Side Band Modulation), and is transmitted to a communication line. When the reception station recognizes said f-signal, a predetermined number of white cells are inserted automatically on a printing paper at the reception station.
A facsimile compression method comprising the steps of reading picture information of an original by a whole scanning line, storing said picture information in a first memory, dividing said picture information of a whole scanning line into a plurality of sections, detecting a black cell in each section, storing the binary information concerning whether each section has a black cell in a second memory, selecting either picture information or an f-signal for each section having no black cell according to the content of said second memory, editing a facsimile signal having a synchronization signal at the beginning of each scanning line, a picture information for each sections having a black cell, and an f-signal for sections having no black cell, and modulating the facsimile signal with an AM.PM.VSB system, and transmitting the modulated signal to a reception station through a communication line.
A facsimile compression system comprising a sensor for reading scanning information of an original, a first memory for storing said scanning information by a whole scanning line, a black cell detector for detecting whether each section in a scanning line has any black cells, a compression control having a second memory for storing the binary information applied from said black cell detector, an f-signal generator indicating that a section has no black cell, a synchronization signal generator, an adder for selectively adding the outputs of said first memory, said f-signal generator and said synchronization signal generator, a modulator for modulating the output of said adder by an AM.PM.VSB system and sending the modulated signal to a communication line, and said second memory being arranged to selectively trigger either the said first memory, the f-signal generator or the synchronization signal generator according to the presence of a black cell in each section.
Dependencies are inferred from the claim text.