JPS5757087A - Copying device - Google Patents

Copying device

Info

Publication number
JPS5757087A
JPS5757087A JP55133208A JP13320880A JPS5757087A JP S5757087 A JPS5757087 A JP S5757087A JP 55133208 A JP55133208 A JP 55133208A JP 13320880 A JP13320880 A JP 13320880A JP S5757087 A JPS5757087 A JP S5757087A
Authority
JP
Japan
Prior art keywords
filter
noise
frequency
read
eliminated
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP55133208A
Other languages
Japanese (ja)
Inventor
Takashi Kitamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP55133208A priority Critical patent/JPS5757087A/en
Publication of JPS5757087A publication Critical patent/JPS5757087A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/40—Picture signal circuits
    • H04N1/409—Edge or detail enhancement; Noise or error suppression

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Laser Beam Printer (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Facsimile Image Signal Circuits (AREA)
  • Dot-Matrix Printers And Others (AREA)

Abstract

PURPOSE:To obtain a smooth picture which has the noise due to quantization is eliminated, by causing the ouput, which is quantized in respect to time, of a discrete read element to pass through a low pass filter. CONSTITUTION:The output of a read element 6 has a pulse amplitude modulated waveform as shown in figure (a). This pulse amplitude modulated wave passes through a low pass filter 7. At this time, the cut-off frequency of the filter 7 is half or less of a sampling frequency, namely, the read clock frequency generated by a clock generating part 21. Therefore, a waveform of the original picture signal as shown in figure (b) is obtained by the Shannon's sampling theorem. Thus, the defect of the ruggedness in the picture peripheral part is resolved. Further, even if a noise is superposed onto the read signal, it is eliminated by the filter if it is a high frequency noise.
JP55133208A 1980-09-24 1980-09-24 Copying device Pending JPS5757087A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55133208A JPS5757087A (en) 1980-09-24 1980-09-24 Copying device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55133208A JPS5757087A (en) 1980-09-24 1980-09-24 Copying device

Publications (1)

Publication Number Publication Date
JPS5757087A true JPS5757087A (en) 1982-04-06

Family

ID=15099253

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55133208A Pending JPS5757087A (en) 1980-09-24 1980-09-24 Copying device

Country Status (1)

Country Link
JP (1) JPS5757087A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62252260A (en) * 1986-04-25 1987-11-04 Ricoh Co Ltd Document reader
FR2751417A1 (en) * 1990-02-01 1998-01-23 Sextant Avionique Airborne method for determining magnetic moment of submarine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62252260A (en) * 1986-04-25 1987-11-04 Ricoh Co Ltd Document reader
FR2751417A1 (en) * 1990-02-01 1998-01-23 Sextant Avionique Airborne method for determining magnetic moment of submarine

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