SE190849C1

SE190849C1 -

Info

Publication number: SE190849C1
Authority: SE
Publication date: 1964-01-01

Description

Uppfinnare: S F Reed Prioritet begard fran den 17 putt 1957 (USA) Den foreliggande metoden avser ett satt for att erhMla forbattrad kontrast vid fotografiska processer. Inventor: S F Reed Priority requested from 17 putt 1957 (USA) The present method relates to a method for obtaining improved contrast in photographic processes.

Tidigare har man sat att erhalla det efterstravade resultatet genorn anvandning av exempelvis fotografiskt papper med hag kontrast resp. genom manuell retusch av fotografisk film. Dessa salt ha dock erfordrat lang tid och ha joke 'heller varit tillrackligt noggranna. Man har aven sokt utnyttja elektroniska metoder men de tidigare kanda ha visat sig tendera att ge likformigt exponerade kopior, vilket icke vent onskvart. Previously, it has been set to obtain the desired result through the use of, for example, photographic paper with hag contrast resp. by manual retouching of photographic film. However, these salts have required a long time and have also been sufficiently accurate. Attempts have also been made to use electronic methods, but the previous ones have been shown to tend to give uniformly exposed copies, which is not expected.

Den foreliggande fotografiska metoden omfattar en avsokning med en ljusflaek av ett foremal som skall avhildas genom en ljusstrale, vilken utsandes fran en ljuskalla och ledande av ljuset frail foremalet till en fotokanslig yta far astadkommande av en reell Mid av foremalet pa den nyssnamnda ytan, varvid medelst en ljuskanslig anordning sker en avkanning av intensiteten av det ljus som riktas mot den fotokansliga Van och en fran den fotokansliga anordningen erhallen spanning via en .forstarkare tillfores ljuskallan som styrspanning. The present photographic method comprises a scanning with a light flake of an object to be repelled by a light beam, which is emitted from a light source and conducting the light from the object to a photoconsipital surface to produce a real Mid of the object on the surface just mentioned. In a photovoltaic device, the intensity of the light directed towards the photoconsultant van is sensed and a voltage obtained from the photocanslable device is supplied to the light source as a control voltage via an amplifier.

Det far uppfinningen sarskilt kannetecknande är att forstarkaren modifierar ljusstralen far erhallande av Rad paverkan av den fotokansliga ytan vid okning av den avkanda ljusintensiteten, dvs. sã att en positiv Aterkopplingsverkan erhalles. What is particularly remarkable about the invention is that the amplifier modifies the light beam by obtaining Rad effect on the photocanal surface when increasing the transmitted light intensity, i.e. so that a positive feedback effect is obtained.

I den efterfoljande heskrivningen har samma sak i vissa fall angivits genom att man. talat em att forstarkaren arbetar enligt en positiv funktion av den avkanda ljusintensiteten. Den egenskap hos ljusstralen, som modifieras enligt en funktion av den avkanda intensiteten ken utgaras av ljusstralens intensitet och/eller ytan lies den av stralen alstrade ljusflacken. Den fotokansliga ytan expo- neras for ljus, som 5verforts frail varje del av .foremMet medelst genom foremalet lett ljus. Det till avkanningsanordningen ledda ljuset kan averfaras genom den fotokansliga ytan eller reflekteras mot denna. Ljuskallan utgares foretradesvis av .ett katodstraleror av bildrartyp. In the subsequent description, the same thing has in some cases been stated by. It is said that the amplifier works according to a positive function of the detected light intensity. The property of the light beam, which is modified according to a function of the sensing intensity, is determined by the intensity of the light beam and / or the surface lies in the light surface generated by the beam. The photocanal surface is exposed to light which is transmitted from each part of the mold by means of light formed through the mold. The light directed to the sensing device can be experienced through the photocanal surface or reflected against it. The light skull is preferably made of a cathode ray tube of the imaging type.

Foretradesvis avs8kes faremalet i tvä dimensioner, varvid avsokningen sker medelst avsokningssignaler, vilkas upprepningsfrekvenser stâ i ett forhallande till varandra som icke utgor ett heltal, varigenom foremalets hela yta kommer att avsokas utan att nagot fast linjemonster uppkommer. Preferably, the hazard is scanned in two dimensions, the scanning taking place by means of scanning signals, the repetition frequencies of which are in a relationship to each other which does not constitute an integer, whereby the entire surface of the object will be scanned without any fixed line pattern.

Uppfinningen skall narmare beskrivas i anslutning till den bifogade ritningen, dar fig. 1 schematiskt visar anvandningen av uppfinningen vid kontaktkopiering fran en fotografisk genomskinlig utgangsbild, medan fig. 2 likaledes schematiskt visar anordningen anvand vid framstallning av kopior genom pro-j ektion. The invention will be described in more detail in connection with the accompanying drawing, in which Fig. 1 schematically shows the use of the invention in contact copying from a photographically transparent starting image, while Fig. 2 also schematically shows the device used in the production of copies by projection.

Ett katodstraleror eller bildrar 10 ar forsett med en. katod 12, ett styrgaller 14, avbajningsplattor 16, vilka aro anslutna till en horisontalavbajningsgenerator 18, samt avbojningsplattor 20, som aro kopplade till en vertikalavbojningsgenerator 22. Den i roret frambragta elektronstralen astadkommer ljus pa en fluoreseensskarm, som är anordnad vid en ande pa r6ret, och ljuset fran denna skiirm ledes genom en genomskinlig fotografisk utgangsbild 26, vilken an insatt mellan en glasplatta 28 och en. fotokanslig yta 30, pa vilken den slutliga kopian kornmer att utbildas. Mellan glasplattan 28 och katodstraler8ret 10 visas en lins 32, vilken anvandes, nfir katodstralerarets fluorescensskarm fir mindre an det genomskinliga fotografiska foremal (bild) 26, som skall reproduceras. Da katodstraleraret har en skfirm som är lika stor som eller 2— — storre an fOremalet 26, kan linsen 32 utelamnas. Pa andra sidan av den fotokansliga ytan 30 och i ljusets vag är ett fotomultiplikatorror 34 anordnat inuti en ljussamlande anordning 36 f8r att avkanna intensiteten hos det fran den fotokansliga ytan overforda ljuset, vilket i detta fall genomtrangt ytan i fraga. Utsignalen fran fotomultiplikatorroret 34 f8- res till en forstarkare 38 for positiv aterkoppling, dar nivan kan regleras pa vanligt satt och dar forstarkarens utsignal genom en led-fling 40 tillfOres katodstralerorets styrgaller 14 for att alstra en positiv aterkopplingsverkan, genom vilken kontrasten hos den erhallna kopian kommer att vara hog i jamfOrelse med kontrasten hos den genomskinliga fotografiska utgangsbild, som den harstammar fran. P liknande satt kan utsignalen fran forstarkaren 38 anvandas for att uppoka kontrasten genom att modifiera avsokningshastigheten och/eller ljusflacksstorleken enligt en bestamd.funktion av den av fotamultiplikatorroret avkanda ljusintensiteten. A cathode ray tube or forming 10 is provided with a. cathode 12, a guide grid 14, deflection plates 16, which are connected to a horizontal deflection generator 18, and deflection plates 20, which are connected to a vertical deflection generator 22. The electron beam produced in the tube provides light on a fluorescence screen arranged at a and the light from this screen is passed through a transparent photographic output image 26, which is inserted between a glass plate 28 and a. photoconductive surface 30, on which the final copy is to be trained. Between the glass plate 28 and the cathode ray tube 10, a lens 32 is shown, which is used for the fluorescence screen of the cathode ray tube for less than the transparent photographic object (image) 26 to be reproduced. Since the cathode ray tube has a shield equal to or greater than the size of the object 26, the lens 32 can be omitted. On the other side of the photocanal surface 30 and in the vague of the light, a photomultiplier tube 34 is arranged inside a light collecting device 36 for sensing the intensity of the light transmitting from the photocanal surface, which in this case penetrates the surface in question. The output of the photomultiplier tube 34 is fed to an amplifier 38 for positive feedback, where the level can be regulated in the usual way and where the amplifier's output signal through a lead flap 40 is supplied to the cathode ray tube guide grid 14 to produce a positive feedback effect. will be high in comparison with the contrast of the transparent photographic output image from which it originates. Similarly, the output of amplifier 38 can be used to increase the contrast by modifying the scan rate and / or the light spot size according to a particular function of the light intensity sensed by the photomultiplier tube.

Den i fig. 2 visade anordningen visar kopiering medelst projektion pa en fotokanslig yta, som ãr ogenomskinlig for det ljus som frail katodstraleroret 10 riktats mot ytan i !raga. I detta fall overstiger arean hos den kopia, ,som skall utbildas pa den fotokansliga ytan 42, arean has den genomskinliga utgangsbilden 26, och linsen 32 astadkommer harvid den erforderliga forstoringen. Eftersom den yta som uppbar den fotokansliga belaggningen 42 ar ogenomskinlig for det av katodstralerOret alstrade ljuset, faller fran ytan i fraga reflekterat och Overfort ljus pa det i uppsamlingsanordningen 36 forefintliga fotomultiplikatorroret 34 for att mata forstarkaren 38 for positiv aterkoppling, vilken i sin tur astadkommer den positiva aterkopplingen pa katodstralerOrets styrgaller 14 for att Aterigen sakerstalla en avsevard Okning i kontrast hos kopian i jamforelse med den genomskinliga utgangsbilden. Det är givet att genom utbyte till en lamplig lins kan vid den I fig. 2 visade projektionskopieringsanordningen aven forminskning astadkommas. The device shown in Fig. 2 shows copying by projection on a photosensitive surface which is opaque to the light from the cathode ray tube 10 directed towards the surface. In this case, the area of the copy to be formed on the photoresist surface 42 exceeds the area of the transparent output image 26, and the lens 32 thereby provides the required magnification. Since the surface bearing the photoresist coating 42 is opaque to the light generated by the cathode ray tube, reflected and transmitted light falls from the surface onto the photomultiplier tube 34 present in the collection device 36 to feed the positive feedback amplifier 38, which in its return positive feedback on the cathode ray tubes of the control grid 14 to again cause a significant increase in contrast of the copy in comparison with the transparent output image. It is a given that by changing to a suitable lens, a reduction can also be achieved with the projection copying device shown in Fig. 2.

Modifikationer och andringar kunna ske mom patentansprakens ram utan att uppfinningsiden frangas, och uppfinningen ar givetvis icke begransad till de bada visade utforingsformerna. Modifications and alterations may be made within the scope of the patent claims without departing from the spirit of the invention, and the invention is of course not limited to the two embodiments shown.

Claims

Patent claim:

A photographic method comprising scanning with a light flake of an object to be imaged by a beam of light emitted by a light source, and directing the light from the object to a photoresist surface to produce a real image of the object on the surface just mentioned. a light-sensing device senses the intensity of the light directed at the photo-sensing surface and a voltage obtained via the amplifier is supplied to a light source as a control voltage, characterized in that the amplifier (38) modifies the light beam to obtain Rad effect. the photo-sensory surface when increasing the transmitted light intensity, i.e. said that a positive feedback effect is obtained.

Method according to claim 1, characterized in that the degree of feedback for the positive feedback effect is installed by means of a reference survey, which is supplied to the amplifier (38). Request publications: Patents from France 1,130,381.