DE1497153A1 - Apparatus for making prints on a web of electrophotographic paper - Google Patents

Description

Dr. Hans-Heinridl Willrath, Wiesbaden, June 13, 1965 Dipl. ~ Ing. Harry Roever 1A 9 71 5 3 h «*» ·. »Dr.w / dp PATENTANWÄLTE t «w." (««,) Telegram address: WILLPATENT Postal check: FrankfurtfMaln er β » Bank: Dresdner Bank AG. Wiesbaden

H 50 956 IXa / 57a Tr.A.II Harris-Inter type Corp.

Harris-Intertype Corporation, 55 Public Square, Cleveland 13, Ohio / USA

Apparatus for making prints on a web of electrophotographic paper

Priority; Ser. No. 240 253 dated November 27, 1962 in the USA

The invention relates to an apparatus for producing prints on a web of electrophotographic paper which in particular for the production of enlarged Druoke from one Micro original, e.g. microfilm, is suitable.

When using microfilms or microcards, the reproduction of the stored information has given rise to certain difficulties. The '· Information can contain sharp lines, whole tones or halftones, such as photographs or drawings that appear in the original document in conjunction with text. You can also Micro-originals can also be used as templates for the production of enlargements in one or more colors »

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In addition to the difficulty of making usable copies of the micro-sized information stored is another difficulty in making copies of single material at a relatively high speed and speed given in a relatively simple way.

These difficulties are overcome according to the invention the creation of an improved, relatively compact micro-printer based on the principle of electrostatic photography works and uses an image carrier on which the electrostatic image is generated and developed on this carrier, wherein an improved charger and an improved developer unit can be used which cooperate in the production Enlarged print of a micro-original within one Relatively short period of time,

The main object of the invention is to provide a Device by means of which you can quickly and easily create a larger Number of copies on a tape of electrophotographic paper can make. In view of the high thermal running speed of the paper and the high operating speed of the device, it is important that the a uniform electrostatic charge on the entire Strip width, in exact alignment with the relevant image pattern from one copy to the other. "." In addition, the invention achieves the object on one and the same section of the electrophotographisohen paper web

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several, i.e. at least two images to be copied in appropriate congruence «

The subject of the invention is therefore a device for producing prints on a web of electrophotographic paper with a feeding and moving device for the paper strip, an electric charging station, a lighting station and a development station, characterized in that the exposure device comprises a table which supports the strip during exposure, and a projector spaced from the Titoh with a light source and lens for producing an enlarged image of the original on the electrophotographic surface.

In the device according to the invention there is preferably a device for automatic control in the exposure station The frequency of the exposure with a light pattern is provided to ensure that the individual images are copied on the continuous strip with the same distance, as close as possible will.

In order to be able to produce a plurality of prints in the same area of the strip, in a preferred embodiment of the invention a device for applying a register mark to the electrophotographic surface of the paper and a readout device in a 4-way movement path are also provided SiBi provided above & l strip STTR determination dtr mark ₁ se that • in more * image "will eraeugt the other images in voreestimmter lag opposite the mark on the strip * can.

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In two ways, this device has at least two charging stations, two lighting stations and two development stations. for charging, exposing and developing a portion of the strip, the first exposure station having means for Generation of a high-intensity flash light to generate a registration mark on the surface during exposure has, iui also has a scanning device for determining the Position of the register marking during the subsequent exposure processes for the formation of a second image in register with a previously separated image, and also a means cooperating with the scanning device for switching on the llohtergenerating device of the second lighting station for Generation of a second image in register with the first are provided.

Further details of the invention emerge from the following, the description based on the drawing.

Fig. 1 is a somewhat schematic view of the electrophoto-

graphical printing machine according to the invention.

Fig. 2 is a somewhat schematic view of a multicolor electrophotographic printing machine.

Fig, 3 shows the scanning system for the sohematieoh Regietermarkierungen at successive printing according to the invention.

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Fig. 4 is a circuit diagram for the exposure device and Register mark.

Fig. 1 shows an electrophotographic microfilm enlarging device with a base 12 on which a take-up roller with Clamping device 14 and at a distance therefrom with a winding coil Clamping device 15 are mounted. Between the devices 15 and 15 there is a charging unit 17 "a projection ·" station 20 and a development station 21 (including a Durohzugsmotors 22 for the strip). A strip 23 "that of a supply roll 25, which is carried by the device 14, is pulled through the masohine by the pull-through motor 22. The strip 23 has on its overhead side 27 is an electrophotographic version of the type described in Applicant's U.S. Patent Application 640 353 dated February 15, 1957 is described «

The development station 21 is supported on the base 12 by means of a further support frame 29, which also acts as a carrier at the same time the Durohzugsmotors 22 is used. A reduction gear 31 connects the motor 22 via a drive belt 32 to a developing roller 33 »which is arranged transversely to the direction of movement of the strip and is rotatably mounted in a developing tank 35, which is carried by the frame 29, in such a way that the paper strip around the outer circumference of the roller 33 and a? Squeegee to a trooken unit 37, which also runs from the sookel 12, lying below the projection unit 20, is carried.

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The microfilm projector used in the apparatus of FIG can be a flash tube, a condenser lens system, a transparent holder with adjustment facility, a projection lens and a projection table that supports the paper during exposure exhibit. A flash tube device is used twice, which provides high intensity light for a very short period of time so that the image creates; can be done without looking at the paper stop in the projection station. Satisfactory results have been obtained using the electronic flash tube of the PT 524 type, which is cooled by air blown over it. The attitude for this flash tube unit becomes more detailed described below.

Another feature of the present invention is one electrophotographic apparatus used to make multicolor prints on a strip of electrophotographic paper can. The paper is on the clamping device 303 of the fed to the first charging station 304, in which the electrophotographic Paper surface receives a uniform charge in the manner described above. From the first charging station the paper runs to the first exposure station 305 »the one Strip support plate 307 and a microfilm projector 309 carried by frame 310. As a microfilm projection device if a flash unit is again preferably provided which generates a high light intensity in a short period of time, see above that the strip did not stop during the exposure period. must become.

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When the strip has now been exposed, it bears an electrostatic, latent image which subsequently develops is by passing the strip through a first development station is passed through. Since that in the first lighting station The electrostatic latent image generated represents only one color of a multi-image image, is that in the first development station liquid developer used is selected to produce a color corresponding to the color of the line separation microfilm representation of the first color of the multicolored image.

After the first image has been printed, the strip can be printed A series of stations are carried out in which, one after the other, a charge is generated and the charged strip is exposed and the charge image is developed, in the following stations provision is made for the scanning of a registries marking that occurred during the creation of the first image made of paper. This registration mark is used for all subsequent exposures to dissolve the Flash unit, so that the successive multicolor images too can be generated in precise registration and deokung. In each Trap represents the electrostatic latent image that exists in each individual A particular color of a multicolored image is generated at a station and is the correct one in a liquid developer Color develops.

When entering the last station, it is in the charging station 320 given the strip a glelohmHeelge charge, and the Strip is exposed in station 322, and then in the

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Station 324 developed in which a Durohzugsmotor 325 is provided. The developed image is then fed through the strip tensioning device 326 to a take-up spool 330 which is in the frame of the machine and has already been described above.

It is important that each of the stations between the first and last station is completely identical to the arrangement explained in connection with the single color printing described, with the one exception that the color of the developer in Each station is different, as is the light distribution projected in each station.

The register recording unit can be understood in connection with FIG. 3, which shows a partial view of a paper strip 335 an index mark 337 moving past the receiving station. A suitable light source 340 with a Projection lamp, a lens system 341, apertures 343 and 344, and a second lens 345 projects along a light point a strip edge. The light is from the strip 335 through a photocell lens system 347 and through a mask 349 to one Eotomultiplier tube 350 reflected. When the register mark passes through this point of light, the light intensity entering the photomultiplier is reduced. The signal is generated when the marker is in a very specific exact position within the illuminated area, i.e. when the image of the marking through the opening in the mask hinduro runs. The flash tube of the projection system is now switched on by a suitable electrical circuit,

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so that a light image is projected onto the surface of the strip is when the leading edge of the register mark on the Acquisition unit passes.

In a multicolor printing device of the type described above, or in the single-color device as described above as described, the projected image can be aligned in each station by focusing and registering the projected images with respect to the index mark. When this operation Once performed, there is automatic production of multicolor images with the multicolor printing device possible. In the case of the single-color device, the paper strip can be wound up and passed through a second time to generate a second image, or several more times to generate more images of one color that are in register with one another and result in a composite multicolor image. When the single color unit is used to produce multicolor images, so a registration recording device of the type described above is used to correspond to the register mark to trigger the flash device in order to generate images one after the other that are exactly in register with the previous ones generated and developed images.

In Fig. 4 is the circuitry for the flash tube and for the register control unit dated; A 110 volt alternating voltage is applied to the connection terminals 479, and two fuses 481 are connected to these two connection terminals. If the Switch S. are closed, the filaments are in the both full-wave rectifiers 483 and 485 switched on, and

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although in the same way as a fan 487 that cools the flash tube 489. The heating voltage is fed to the triggering thyratron 490. After closing the switches S. and S », the control lamps 501 and 502 light up and indicate that the circuit is now in operation. About 30 minutes after the switch S _{2 has been} closed, the time control device 505 closes so that the voltage can now reach the anode of the thyratron tube 490. The correct voltage is fed to the rectifiers 483 and 485 by means of a transformer 507 and the step transformer 510. The transformer 515 feeds the filaments and provides the throughput of the tubes 483 and 485. The series of resistors, designated as a whole by 517, supplies the anode voltage for the trigger thyratron 490. Pin connections 518 and 519 are provided for conducting the high voltage to the flash tube circuit. A capacitor 520 is charged by the two charge limiting resistors 521 and 522, and the measuring device 526 is used to display the voltage on the capacitor 520.

There are three ways to use the flash sequence of the flash tube 489 * In the first way, the switch 527 is closed, and 528 is open so that the thyratron tube 490 is biased as a relaxation oscillator to drive the flash tube at a frequency trigger from about 20 to 30 cycles per second. This working method can be used when the images are aligned or the Lens systems of the projection system are focused.

In another mode of operation, switch 527 is open and 528 is open is closed, the thyratron tube 490 is via the Zener diode 550 biased, and tube 49P only flashes when it

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is triggered. With this setting the capacitor is on 520 in the flash circle, and a microscope holder provided between contacts 55 * and 552 can be used for controlled triggering of the flash tube. This way of working is particularly useful in those cases in which single-color operation is planned.

The third mode of operation is controlled by the photocell 455, which via the capacitor 556 the thyratron grid always then one positive pulse if there is a dark spot on the strip. In this mode of operation, the photocell registration mark recording system is used to trigger the trigger to control the flash tube.

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Claims (3)

Claims ζ *
1.) Device for the production of prints on a web of ^ electrophotographic paper with a guide and movement device for the paper strip, a station for application a uniform electrostatic charge on the electrophotographisohen Surface, an exposure station and a development station, characterized in that the exposure device comprises a table which supports the strip during exposure and a projector spaced from the table with a light source and a lens for producing an enlarged image of the original on the electrophotographic Surface. 2.) Device according to claim 1, characterized in that in the Exposure station a device for automatically controlling the frequency of exposure with a Liohtmuster is provided. 3.) Device according to one of claims i or 2, characterized in that that to enable the production of a plurality of prints in the same area of the strip a device for applying a register mark on the electrophotographi sohen surface of the paper and a mark reading ~ Vorriohtung in the movement path of the strip to determine the. Marking are provided so that another picture or wider. re images in a predetermined position opposite the marking on the Stripes can be generated. 9098 2A / 05 55 h.) Device according to one of claims 1 to 3 »characterized in that it has at least two charging stations, two exposure stations and two development stations for charging, exposure and development of a part of the strip, the first exposure station having a device for generating a high-intensity flash light for Generating a registration mark on the surface during the exposure further comprises a scanning device for determining the position of the register marking during the subsequent exposure processes for the formation of a second image in register with a previously placed image, and also a device cooperating with the scanning device for switching on of the light-generating device of the second exposure station for generating a second image in register with the first. 909824/0555 ■ -η- Le e rs e it