SE190848C1

SE190848C1 -

Info

Publication number: SE190848C1
Authority: SE
Publication date: 1964-01-01

Description

Uppfinnare: D R Craig Foreliggande uppfining hanfor sig till en fotografisk metod och apparat, genom vilken likformigt .exponerade kopior (avtryek) kunna frambringas fran olika foremal, vilka icke skulle Tara i stand att frambringa dylika kopior enligt konventionella metoder. Inventor: D R Craig The present invention relates to a photographic method and apparatus by which uniformly exposed copies (imprints) can be produced from various objects which would not be capable of producing such copies by conventional methods.

Den fiireliggande uppfinningen avser en svarigheter kringgaende fotografisk metod, vilken innefattar matning av en ljuskalla for alstring av ett variabelt ljusknippe, ledande av detta ljusknippe mot ett foremal f6r att upplysa en del av detta genom en ljusflack med iindlig area, avsOkning av forernalet med namnda ljusflack och ledande av ljus frau varje del av namnda foremal for formande av en reell bud pa en fotokanslig yta for att exponera denna, ledande av ljus fran den fotokansliga ytan till ljusavkannande organ, And-ring av ljusknippet i beroende av de intensitetsvariationer som avkants av namnda organ für att bibehalla medelljusintensiteten pa alla delar av den fotokansliga ytan i huvudsak konstant, samt ytterligare andring av ljusknippet i beroende av det integrerade vardet av det ljus som harletts fran en del av namnda fOremal. Stralknippets intensitet Andras fOretradesvis i beroende av den avkanda intensitetsvariationen. Stralknippets totala avsOkningstid Andras foretradesvis i beroende av det integrerade vardet av ljuset. En betydelsefull tillampning av uppfinningen avser det fallet, att foremalet utgores av en genomsiktshild, genom vilket ljuset ledes och dar den ytterligare andringen av ljusknippet Sr beroende pa tatheten hos en del av genomsiktsbilden. The present invention relates to a photographic method which comprises feeding a light source for generating a variable light beam, guiding this light beam towards an object for illuminating a part thereof through a light flake with a finite area, scanning the forernal with said light flake and conducting light from each part of said object to form a real bid on a photocanal surface to expose it, conducting light from the photocanal surface to light sensing means, changing the light beam depending on the intensity variations indicated by said means for maintaining the average light intensity on all parts of the photocanal surface substantially constant, as well as further change of the light beam depending on the integrated value of the light obtained from a part of said object. The intensity of the beam is secondarily preferred depending on the known intensity variation. The beam's total scanning time is secondarily preferred depending on the integrated value of the light. A significant application of the invention relates to the case that the object is constituted by a transparent shield through which the light is passed and where the further change of the light beam Sr depends on the density of a part of the transparent image.

Uppfinningen avser Sven en fotografisk apparat innefattande uppbarande organ for en genomsiktsbild och en fotokanslig yta, en ljuskalla som frambringar ett knippe som avsoker genomsiktsbilden och exponerar ytan, ljusavkannande organ anordnade I banan for det ljus fran ljuskallan som genomgar genom siktsbilden, ,forsta organ i kopplingsforbindelse med det ljusavkannande organet for att Andra ljusknippet i beroende av de avkiinda intensitetsvariationerna, samt andra organ i kopplingsforbindelse med det ljusavkannande organet for andring av ljusknippets totala avsokningstid. Ljuskallan utgores foretradesvis av ett katodstralerOr, och det ljusavkannande organet omfattar en fotoelektrisk anordning. Det andra i kopplingsforbindelse med det ljusavkannande organet staende organet innefattar foretradesvis en integrationsanordning och det forsta organet foretradesvis en aterkopplingsforstarkare for vaxelspanningar. Det ljusavkannande organet avses att besta av ett flertal fotoelektriska anordningar, med millstone en i kopplingsforbindelse med var sitt av de forsta och andra organen. Under dessa omstandigheter skall Sven en av de fotoelektriska anordningarna vara forsedd med medel 'for andring av synfaltet. The invention relates to a photographic apparatus comprising supporting means for a transparent image and a photosensitive surface, a light source which produces a bundle which scans the transparent image and exposes the surface, light sensing means arranged in the path of the light from the light source passing through the screen image, first means in connection with the light sensing means for changing the second light beam in dependence on the transmitted intensity variations, and other means in connection with the light sensing means for changing the total scanning time of the light beam. The light source is preferably constituted by a cathode ray tube, and the light sensing means comprises a photoelectric device. The second means in connection with the light-sensing means preferably comprises an integration device and the first means preferably a feedback amplifier for alternating voltages. The light sensing means is intended to consist of a plurality of photoelectric devices, with at least one in coupling connection with each of the first and second means. Under these circumstances, one of the photoelectric devices must be provided with means for changing the field of view.

Enligt den metod och apparat som konstituera den foreliggande uppfinningen aro tva oberoende aterkopplingskanaler anordnade. Pa sa satt kunna, eftersom saval ett mycket Mit som ett myeket tunt negativ i fraga om tathetsvariationerna kunna uppvisa samma monster, enligt uppfinningen fran de ifragavarande negativen framstallda kopior utsattas for exponering med samma medelniva. According to the method and apparatus constituting the present invention, two independent feedback channels are provided. In this way, since both a very Mit and a very thin negative in the case of the density variations can show the same sample, according to the invention copies produced from the negatives in question are exposed to exposure with the same mean level.

Uppfinningen kan Rastas bathe genom den efterfoljande beskrivningen i forening med de bifogade ritningarna, dar fig. 1 schematiskt visar en form av uppfinningen och fig. 2 en modifiera:d form av denna. The invention can be bathed by the following description in conjunction with the accompanying drawings, in which Fig. 1 schematically shows a form of the invention and Fig. 2 a modified form thereof.

Ett katodstraleror eller bildror 10 Sr forsett med en katod 12, ett styrgaller 14, avbojningselektroder 16 i kopplingsforbindelse med en horisontalavb8jningsgenerator 18, samt avbojningselektroder 20 i kopplingsforbindelse med en vertikalavhojningsgenerator 22. Den I roret alstrade elektronstralen frambringar ljus pa en fluorescensskarm 24 vid rorets an- 2— — de. Ljuset harifran riktas medelst en lamplig lins 26 genom en fotografisk genomsiktsbild 28 och en yta 30, som fotosensiterats och pa vilken den slutliga kopian skall utbildas. Om katodstralertirets skarm är lika stor som gpnomsiktsbilden, kan linsen 26 uteslutas och genoinsiktsbilden och den fotosensiterade Van flyttas narmare intill den med fluorescensskarm fOrsedda anden ptt roret 10. A cathode ray tube or picture tube 10 is provided with a cathode 12, a guide grid 14, deflection electrodes 16 in connection with a horizontal deflection generator 18, and deflection electrodes 20 in connection with a vertical deflection generator 22. The electron beam 24 generated in the tube 2— - de. The light from here is directed by means of a lamp lens 26 through a photographic transparent image 28 and a surface 30, which has been photosensitized and on which the final copy is to be formed. If the screen of the cathode ray tube is as large as the transparent image, the lens 26 can be omitted and the genoinsight image and the photosensitized Van moved closer to the fluorescent screen spirit on the tube 10.

Bakom den fotosensiterade. ytan 30 och i det av katodstraleroret alstrade ljusets vag är mom en ljussamlare 34 ett fotomultiplikatorror 32 anordnat f8r att avkanna intensiteten hos det ljus, som passerat genomsiktsbilden och den fotosensiterade ytan. Fotomultiplikatorroret är Over ledningar 36 och 38, strom-; stallaren 40, en aterkopplingsfOrstarkare 12 for vaxelspanningar och ledarna 44 ooh 46 anslutet till katodstralerorets galler 14 for att astadkomma en aterkopplingsverkan, som är beroende pa de intensitetsvariationer fotomultiplikatorrOret 32 har avkant. I de fiesta fall astadkommer kopplingen en negativ aterkoppling, vars storlek kan injusteras genom limp-hg installning av forstarkaren pa konventionellt satt, for att alstra andringar av erforderlig storlek. Behind the photosensitized. surface 30 and in the light generated by the cathode ray tube, a light collector 34 is provided with a photomultiplier tube 32 to sense the intensity of the light which has passed the transparent image and the photosensitized surface. The photomultiplier tube is Over wires 36 and 38, current-; the stall 40, a feedback amplifier 12 for alternating voltages and the conductors 44 and 46 connected to the grid 14 of the cathode ray tube to provide a feedback effect which is dependent on the intensity variations of the photomultiplier tube 32. In most cases, the coupling provides a negative feedback, the size of which can be adjusted by limp-hg installation of the amplifier in a conventional manner, in order to produce changes of the required size.

Fotomultiplikatorroret 32 är genom sin utgangsledning 36 aven anslutet till en av ledningen 48, en ljusintegrerande anordning 50, saint ledningen 52 och ledaren 46 bestaende koppling for ytterligare andring av katodstralerorets arbetssatt. En. anordning 64 for reglering av exponeringsfaktorn visas ansluten till den ljusintegrerande amkopplaren 50 for avagabringande av den onskade exponeringsniva.n. The photomultiplier tube 32 is also connected through its output line 36 to one of the lines 48, a light integrating device 50, the saint line 52 and the conductor 46, for further change of the operation of the cathode ray tube. One. device 64 for controlling the exposure factor is shown connected to the light integrating switch 50 for discharging the desired exposure level.

Eftersom det tar mindre tid att na en given exponeringsniva genom ett tunt negativ an genom ett Hit sadant, kan en avsevard tid sparas vid framstallningen av kopior fran negativ, vilka varierar i tathet sinsemellan, genom att aterkoppla endast vaxelspanningskomposanten samt kombinera detta med anvandandet av den integrerande anordningen. Detta utgOr en bestamd forbattring i forhallan.de till anvandningen av en enda aterkopplingsslinga. Since it takes less time to reach a given exposure level through a thin negative than through a Hit such, a considerable time can be saved in the production of copies of negatives, which vary in density among themselves, by reconnecting only the AC voltage component and combining this with the use of the integrating device. This constitutes a definite improvement in relation to the use of a single feedback loop.

Vid det har foreliggande systemet kommer den f8r vaxelspanningar avsedda aterkopp- lingsforstarkaren endast att reagera for variationer i negativets tathet, och dessa komma I sin fur vid den visade utforingsformen att alstra variationer hos ljusknippet utan hansyn till den absoluta ljusnivan. In the case of the present system, the feedback amplifier intended for alternating voltages will only react to variations in the density of the negative, and these will in their fur in the embodiment shown produce variations of the light beam without regard to the absolute light level.

Den i fig. 2 visade formen skiljer sig frau den i fig. 1 visade genom anordnandet av en andra ljusavkannande anordning, exempelvis form av ett fotomultiplikatorror 60, som over sin ledning 62 sjalvstandigt WHOr strOm till ljusintegrationsomkopplaren 50. FotomultiplikatorrOret 60 visas inneslutet i ett holje, corn her en installbar hylsa 64 rorlig relativt holjet och darigenom i stand att andra detta fotomultiplikatorrors synfalt. Pa detta salt kan ljusnivan bestammas genom ett eller flera avsnitt hos genomsiktsbilden 28 i stallet fOr att bestammas genom inedeltatheten. Pa detta satt kunna de skadliga verkningarna av fOrbi n.egativets kanter passerande, icke onskat ljus undvikas, och storleken och belagenheten hos synfaltets reglerande avsnitt kan valj as ut fOr att medfora en precis exponering av det intressanta amrade som kan forefinnas. The shape shown in Fig. 2 differs from that shown in Fig. 1 by the arrangement of a second light sensing device, for example in the form of a photomultiplier tube 60, which over its line 62 independently flows to the light integration switch 50. The photomultiplier tube 60 is shown enclosed in a housing. , corn her an installable sleeve 64 rorlig relatively holjet and thereby able to second this photomultiplieratorrors visually. On this salt, the light level can be determined by one or more sections of the transparent image 28 instead of being determined by the subdivision. In this way, the detrimental effects of the passing, unwanted light passing by the edges of the negative can be avoided, and the size and location of the regulating section of the visual field can be selected to cause a precise exposure of the interesting amber that may be present.

For fackmannen ar det givet att olika fikationer kunna vidtagas, varfOr de visade och beskrivna exemplen icke fO. betraktas som begransande utover patentansprakens ram. It is obvious to the person skilled in the art that different fictions can be made, for which the examples shown and described are not fO. is considered limiting beyond the scope of the patent claims.

Claims

Patent claim:

Photographic method for forming a real image of a: forming on a photo-probable surface and obtaining a lamp exposure of the parts of the photo-probable surface in relation to each other, characterized in that the method comprises on the one hand feeding a light source to achieve a variable light beam to illuminate an element surface on this Viremal larger than the finest details to be reproduced but less than to cover the form through a light surface of the same size as the element surface, partly by scanning the object through the just mentioned light surface and conducting the light which arises at the scanning through the light surface to form a real image on the photosensitive surface and exposing the photosensitive surface to the real image, partly continuous sensing of the light from the form by a scanning device for the light intensity, and partly a continuous change of the light beam depending on the sensed intensity variations father to achieve a substantially constant average exposure of the photo office give the surface for the different element surfaces on the object at each scan.

Photographic method according to claim 1, characterized in that the intensity of the light beam changes depending on the known intensity variations.

Photographic method according to claim 1, characterized in that the light beam also changes depending on the time-integrated value of the light obtained from a part of the said object, the integrated value affecting the total scanning time of the light beam.

Photographic method according to any one of the preceding patent claims, characterized in that the form is constituted by a transparent image, through which light is transmitted to the photocanal surface.

5. A photographic apparatus for carrying out the method according to the preceding claims, characterized by the stodargan having a transparent image (28) and a photoconductive surface - 30 (30), a light source (24) for producing a light beam for scanning the transparent image (28). ) and exposure to the photocanal surface (30), a light sensing means (32) arranged in the frail light source (24) coming and the transparent image (28) passing the light vague, and a first means (42) in coupling relationship with the light sensing means (32). ) may change the light beam depending on the known intensity variations.

Photographic apparatus according to claim 5, characterized in that the light source is constituted by a cathode ray tube (10, 21).

A photographic apparatus according to claim 5 or 6, characterized in that the light sensing means comprises a photoelectric device (32).

Photographic apparatus according to any one of claims 5-7, characterized by a second means (50) in the form of an integrating device and in connection with a light sensing means (60) for changing the total scanning time of the light beam.

9. A photographic apparatus according to any one of claims 5-8, characterized in that the first means comprises an amplifier (42) for alternating voltages.

Photographic device according to any one of claims 5-9, characterized in that each sensing means comprises a photoelectric device (32, 60) in coupling connection with each of said first (42) and second (50) means.

Photographic apparatus according to claim 10, characterized in that. one (60) of the photoelectric devices (32, 60) is provided with means (64) for changing its field of view. Cited publications: Patents fain France 1 130 381.