US2458926A - Web scanning device - Google Patents

Description

Jan. 11, 1949. I fo, ss 2,458,926

WEB SCANNING DEVICE Filed March 12, 1948 Inventor" 2 l Mwcm o. Baa-56 Gb 1 WW His Attorney.

Patented Jan. 11, 1949 UNITED STATE New York 7 Application March 12, 1948, Serial N... 14, 133

faciaims. (o1. 25.1-41.5) Y

My invention relates to web scanning devices utilized in connection with a continuously moving web and is related, more particularly, to such devices utilizing light sensitive means responsive to light reflected from or transmitted through such continuously moving web. J j

A principal object of my invention is to provide an improved device of the type described which requires very simple manipulation thereof to ac complish scanning of a continuously moving web by specularly or difiusely reflected light from said movingweb.

' Another object of the type described which is economical to" manufacture and is adapted to be operatedby personnel having a minimum of skill. z

In general, my invention comprises an enclosure which supports within it a pivotal chassis. Mounted on the chassis are alamp and a'photoelectric tube separated by a partition to keep the direct rays of the lamp from entering the proto-; electric tube. The light from the lamp is directed through a lens systemsecured to thepartition to provide a sharply focused area or spot of light on a moving web. As arrari'gedQthe movement of" the chassis moves the locus of thefocalpoint of light along an are between selected positions so as to provide either diffuse or specular reflect-ion of said lightfrom the moving web. The point of pivot is so disposed with respect to the moving web that the light image incident on the web is in' substantial focus at either the difiuse orspecular position. a

The advantage of the above recited arrange ment of my invention is in providing a relatively fixed enclosure, and Without disturbing the position of this enclosure with respect to the webbeing scanned, provide a change from diffuse reflection to specular or back as desired. This is accomp-' lished by rotating the chassis through a pre -j determined arc and causing the spot of light incident on the moving web toshift along said arc between predetermined points so as to alter the angle of reflection with respect to the moving web. The above objects and other advantages of my invention will be better understood from the following description and accompanying drawing. in which Fig. 1 is a side view of an embodiment of my invention with the enclosures broken" away to illustratethe arrangement of the components therein; Fig. 2 is a front view. of my device with the upper enclosure in cross sectionto illustrate the cooperative arrangement of components for operation of the device when utilized for diffusely.

reflected light; Fig. 3 is a second front view with WEB SCANNING DEVICE Merton 0. Bassett, Schenectady, N. Y., assignor" to General Electric Comp any a corporation or is to provide an improvedf'device s I mar-i theupper and a portion of the lowerenclosures in cross section to illustrate the utilization of my device for transmitted orspecularly reflected light; Fig. 4 illustrates the utilization o suitable indicia for indicating the operatin vpositions .of my device Fig. 5 depictsa simplified perspective view illustrating thefapplication of mydevice ,for, scanning a moving web; and Fig. Sis a schematic diagram showing the electrical connections .of my device. j p In the description to followrthe term web is defined as any fiat sheet or ribbon materialsuch as paper, cellulose nitrate material (opaqueor transparent) rubber sheets, metal foil, wood and g i" Theterm light-sensitivedevice? includes such devices as photoelectric tubes of the soft orgas filled types, electron-multipliertypes; bolometer's; photolytic .cells, selenium cells, and like devices;

Referring to the drawing, my scanning head 10- comprises an enclosure-H containinga-movable chassis l2 arranged to pivot about'a point' l3 asshowninFigs.2and3.

Movement of the chassis -I2 is manipulation of a thumbscrew l4 attached-to an extended portion [5 of the chassis, the -thumb.

screw passing throughya slot provided for. this purpose in the frontportion l! of the enclosure l'l. Fig. 4 is a fragmentary view of; the-portion I] with suitable operatingindicia inscribed there- .Mounted upon the chassis |2is a light .source I8, for example, a conventionalautomobile"head light lamp. This type-of light source is preferred;

light'source 24 of the'same type asl8... Th ligl'it source 24 is disposed in an enclosure 25, the en,-

closurebeing secured to the scanning head I [l'bymeans of a connection plug 26 attached to the enclosure 25 for engagement with a receptacle 2'! attached to said scanning head as shown: in Fig. 1.

A single-pole, double throw switch 28 ,is

utnizea to switch the power from the light source accomplished byv l8 to the light source 24 or vice versa at will. A suitable source of electric current supply (not shown) is fed through a connector 29 to energize both light sources I8 and 24 and the photoelectric tube [9.

3 An aperture, 30 is provided in the enclosure 25 so that a beam of light of proper size and shape reaches thephgtoelectric tube .1 8 A in the scopedff'jmsifir'ifvnfiion torutiligelanadifisfi able aperture if so desired.

The power supply circuit is very simple, as illus- H I the components for transmitted light operation trated in Fig. 6, and is one which requires a mi mum of labor to assemble.

When, as shown in Fig. 5 a suitably disposed in relati a e: 22 and the chassis I2 rotated to th of thelightimagereacliesthe photoelectrig tube.

di" t .5 l. l fen le se .sibse iieiw wus tl ,.t l er-positibn A ni-the'iccus'dr-eucfdcar bnit Being r the are etveq gihe r leased Bgm ma ic a new i h a ieeiib enc ure l! e a n s et fi'fl wuiis-tiie ehsngeffis tbisl e luai-geneaticnsisamaee by -ii pi Shir be ppreciate th at arrangement req'u as a mihlinum ofliiiarifpulati by terator a niihimuiii cesium 7? Inasmuch as the application of my deviceis suits-bre-tethese mfihg ef w eb ct fiposee friii'ah amrx' an' usiiiateriais: th acptaunitg t ero examplefiiion is rr e em or'rly requirement" istlle d series of marks vide a siiijfac ljf w 315 h i. scar'i is changew'to provide d th e isci l hil r moving issalso with 6 651 an" illustrated in Fig. 2, the light source image will appear on the web 22 at a poiriiiii? Iii ears-tbsp tion, the specular light image is directedsbaclg into the lens system andlonly the difiusereflection ea e 4 or no light will reach the photoelectric tube thereby providing a similar current response in the photoelectric tube as described above.

For scanning transparent web, direct transmission of light is utilized and the web is marked with an opaque substance. The switch 28 is thrown to the right (with respect to the observer) as illustrated in 4, and' the thumbl screw 14 nipyed under; the :arrow toi'tl're right of theinscription Transmitted light. This position is similar to specular scan. The relative position of operate,

large variety oi material, compact and economical j I 'heiembodiment of my invention which has been illustrated and described has been selected iorthe purpose of setting forth the principles involyledli Itlwill be obvious that my invention maybe modifi'edftomeet various conditions for differentspe'cific uses, audit is, therefore, intendedltol' cover'by the appended claims all such modifications which fall within the spirit and scope of this invention.

What/IQ-cl aim as new and desire'to secure by Letters'Batent of the United States is:

1.. ma photoelectric device for scanning a moving. web,-. a pivotal. support. having mounted thereon a photoelectric tube and an optical system, said'optical system projecting a-lightimage on. said "web and comprising a. light source and focusing. means between said light source and said web, andvnieans for moving said pivotal support betweenftwopredeterminedpositions to shift saidl'ghtimage on said web, said/positionsbeiue' such that he, photoelectric tube receives 'diffuselyrefiected-light in one said position and specularlyreflected light in the other said position;

2111 aphotoelectric device for scanning a moving web; a; pivotal support having mounted thereon: a photoelectric tube and: an optical systern; saidopticalzsystem projecting alight image on said-{web and comprising'a; light source and focusing; means between'said light source and said) web;, and means for rotating said pivotal supporthetween predetermined-positions to cause movement cf the light ima e along e lsne .Q se qim v ne we 3. In a photoelectric device for scanning a moving web, a pivota-l support having mounted an arc in thereon a photoelectric tube and an optical system, said optical system projecting alight image on web: and comprising a light source and tocusing meansbetween said light source and sai web, and means for moving said pivotal sup- 1 port;betweenv two spaced-apart predetermined positions to shift said light image on said web, said position; being such. that said photoelectric tube receives'difiusfly reflected light in one position. and specularly reflected light. in the other position, saidpivotal support being so disposed with'respect tosaid web that said light image is 'i ,'resm 1 said. Web in either of said posiees- 4. In a; photoelectric device for scanning a moving web; a pivotal support, apartition of opaque materialmounted on said support; an opticalfsystem projecting a light image on said web andj comprising a light source secured to saidfsuppoi tongone side of said partition, focusng-.. sen sauce 9 itd Par t diate said light source and moving web. a light sensitive device secured to said support on: the other side of said partition, and means for rotat ing said pivotal support between predetermined positions to cause movement of the light image along an arc in the plane of said moving web;

5. In a photoelectric device for scanning a moving web, a pivotal support having mounted thereon a photoelectric tube and an optical system, said optical system projecting a light image on one side of said web and comprising a light source and focusing means between said light (No references cited.)

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