GB1385689A - Apparatus for detecting changes in optical density in a moving web - Google Patents

Apparatus for detecting changes in optical density in a moving web

Info

Publication number
GB1385689A
GB1385689A GB4720971A GB4720971A GB1385689A GB 1385689 A GB1385689 A GB 1385689A GB 4720971 A GB4720971 A GB 4720971A GB 4720971 A GB4720971 A GB 4720971A GB 1385689 A GB1385689 A GB 1385689A
Authority
GB
United Kingdom
Prior art keywords
photo
amplifier
edge
oct
electrically
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.)
Expired
Application number
GB4720971A
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.)
BOWATERS PAPER CO Ltd
Original Assignee
BOWATERS PAPER CO Ltd
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 BOWATERS PAPER CO Ltd filed Critical BOWATERS PAPER CO Ltd
Priority to GB4720971A priority Critical patent/GB1385689A/en
Publication of GB1385689A publication Critical patent/GB1385689A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/34—Paper
    • G01N33/346—Paper sheets
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Textile Engineering (AREA)
  • Controlling Rewinding, Feeding, Winding, Or Abnormalities Of Webs (AREA)

Abstract

1385689 Detecting edges photo-electrically BOWATERS UNITED KINGDOM PAPER CO 11 Oct 1972 [11 Oct 1971] 47209/71 Heading G1A An edge of a moving sheet material e.g. an edge at a splice between two webs or at a void or hole in the material, is detected photo-electrically. As shown, the web S passes between a daylight type miniature fluorescent tube 3, emmitting predominantly blue or ultraviolet light, and a blue or ultraviolet-sensitive photo-cell 2, since the splicing tape used to join webs has strong absorption of this colour, and effectively cuts off transmission of light to the photo-cell. The source is modulated by a transistorized supply, to produce a 16KHz flicker frequency. The detecter circuit comprises an impedance buffer amplifier 4, potentiometer and logarithmic amplifier 19. The channels of differential amplifier 5 include operational amplifier 6, which has a bandwidth of 1H 2 and responds slowly in accordance with changes in web density, but not to rapid changes such as at an edge, and amplifier 7, having a 10 KHz bandwidth, and responding to rapid changes. The two output channels feeding indicators 16, 16a are respectively for indicating splices and voids (high and low absorption levels).
GB4720971A 1971-10-11 1971-10-11 Apparatus for detecting changes in optical density in a moving web Expired GB1385689A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4720971A GB1385689A (en) 1971-10-11 1971-10-11 Apparatus for detecting changes in optical density in a moving web

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4720971A GB1385689A (en) 1971-10-11 1971-10-11 Apparatus for detecting changes in optical density in a moving web

Publications (1)

Publication Number Publication Date
GB1385689A true GB1385689A (en) 1975-02-26

Family

ID=10444147

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4720971A Expired GB1385689A (en) 1971-10-11 1971-10-11 Apparatus for detecting changes in optical density in a moving web

Country Status (1)

Country Link
GB (1) GB1385689A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2530595A1 (en) * 1980-09-19 1984-01-27 Brandt Pra Inc SHEET DEFECT DETECTION APPARATUS FOR A DOCUMENT PROCESSING INSTALLATION AND METHOD FOR MEASURING THE STRENGTH OF SHEETS
EP0320816A2 (en) * 1987-12-15 1989-06-21 G.D Societa' Per Azioni Device for checking feed conditions of a strip of wrapping material to a user machine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2530595A1 (en) * 1980-09-19 1984-01-27 Brandt Pra Inc SHEET DEFECT DETECTION APPARATUS FOR A DOCUMENT PROCESSING INSTALLATION AND METHOD FOR MEASURING THE STRENGTH OF SHEETS
EP0320816A2 (en) * 1987-12-15 1989-06-21 G.D Societa' Per Azioni Device for checking feed conditions of a strip of wrapping material to a user machine
EP0320816A3 (en) * 1987-12-15 1990-05-16 G.D. Societa Per Azioni Device for checking feed conditions of a strip of wrapping material to a user machine

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees