SU739465A1 - Electrophotographic copying apparatus - Google Patents

Description

(54)

APPARATUS FOR; ELECTROPHOTOGRAPHIC COPYING

.one.

 The invention relates to electrophotography, to microfilming on electrophotographic carriers, 6. in particular, to copying microneedle in the form of microfilm and microfiche.,

Organic electrophotographic layers (EFS) used in electrophotographic microfilming allow the use of I.X. with both positive and negative charge. This suggests the possibility of creating a copying device from any of the four schemes: positive-positive, negative-positive, negative-negative, positive-negative, on the same EFS with the same liquid electrographic designer L-Q.

However, in order to go from one copying scheme to another, it is necessary to change the signs and magnitudes of the voltages applied to the grid and the corona electrodes of the charging device and to the counter-spectrode of the developing device. It is required to change and size

EXPOSITIONS. These parameters need to be changed in aggregate, since microfilming requires a resolution of more than 100-15 O LIN / MM and therefore all stages of the electrographic process must be carried out under optimal conditions.

An electrographic apparatus is known in which the control circuit provides an optimal exposure for obtaining positive copies from negatives or

ten

. .

However, the conditions of charging and manifestation are not regulated here.

A control device for a copier is known which contains

15 a probe section determining the amount of charge of the electrophotographic plate and the electrometer indicating this voltage. The device may have feedback for automatically adjusting the voltage on the counter electrode in the process of developing Sj

However, here, there is no provision for a change in the sign of the charge plate and the correspondence of forces on the charging and display device.

A known apparatus for electrophotographic copying from microfilm onto an electrophotographic film containing mechanisms for moving the copied microfilm and electrofilm, an exposure unit, a charging device and a display with their power sources, a device for removing an excess of developing powder and fixing the developed image, and also a photo detector , with a light source for measuring the optical density of the original, with the output signal of the photodetector being cut through a differential amplifier adjusting Inu voltage of the charging device by comparing the signal of the photodetector with the reference voltage 4.

The disadvantages of this installation are that it is intended only for one copying scheme and lacks the possibility of copying and promptly switching to any of the four schemes: positive-positive positive-negative, negative-negative, negative-positive.

The purpose of the invention is to expand the functionality of the device as well as automatically switching from positive images to negative ones and vice versa.

The goal is achieved by the fact that the device is equipped with a switching unit and two switches, while the switching unit is connected to the exposure unit and the control inputs of the recloser) chat, and the first switch is connected to the charging device and its power source, the second to another source power supply and device development.

The device contains a photo sensor, the output of which is connected to the control input of the switching unit.

The essence of the invention is that with the help of transducers, ateles and logic in a switching unit on a charging device, an exposure unit and counter electrodes of a manifestation device

the required combination of polarities and optimal voltages is required, which are required for any of the four copying schemes. Values. Voltages are set in advance when the apparatus is adjusted.

Introduction of a photo sensor to identify the type of input image positive

or the negative even more automates the device, reducing control to the choice of the type of image on a copy by switching the toggle switch.

The drawing shows the block diagram of the proposed device.

It contains a switching unit 1 to control the process of obtaining n & positive or positive copies from negative or positive originals of microfiches, two switches 2 and 3 to change the magnitude and polarity of the voltages applied to the charging device 4 and the display device 5, two sources 6 and 7 power, a photo sensor 8 embedded in the exposure unit 9; the mechanism 10 for moving the copied microfiche and the mechanism 11 for moving the blank microfiche.

The device works as follows.

A photo sensor 8, consisting of a light source and a photoreceiver, generates signals about the arrival of a negative or positive original microfiche. These signals are transmitted to the switching unit 1 and stored in it. The switching unit, in the presence of signals from the photo sensor, completes the on or off switches 2 and 3 for supplying the required polarity and voltage values to the charging device 4 and the developing device 5 from sources Q and 7 of the power supply in accordance with the data given in table. . 1 of the electrographic process of obtaining copies of microfiches, (negative or positive) with negative or positive originals of microfiches.

Functional switches are associated with both the power sources and the charging and developing devices themselves. These connections provide for the switching on of the power supplies (connection with the sources as well as the supply of a pre-adjusted voltage value (connection C) The circuit elements necessary for the pre-regulation of voltages can be located in the switch 1x, the power sources or the charging and development devices themselves.

The connection of the co-blocking unit with the expansion unit provides for changing the magnitude of the exposure when copying negatives or positives. The change in exposure is made either by changing the voltage on the light source or by the time it is turned on.

The source 6 is switched on by signals supplied from the sensors of the movement mechanism at the moment the microfiche workpiece 12 is mixed from the loading position to the position to be exposed. For example, for a negative-negative and positive developer case, negative voltage is applied to the charge device 4 using switch 2, and the microfiche electrophotocell is charged with negative charge. In the exposure position, the image from the original 13 is transferred to the microfiche blank electrophotolayer 12. Then, the resulting latent electrostatic image

Positive

Positive

Negative

If necessary, in the apparatus set | 1, the drying and fixing units are installed.

The proposed apparatus and its block diagram can be applied even when it is necessary to obtain only positive or only negative copies. In these cases, the number of switchings required is reduced.

For experimental verification of the proposed apparatus, a valid layout is made, on which high-quality copies of microfiches from photographic negative and positive originals are obtained. The optical density of the developed image is 1.1-1.7, resolution 18O-20O mm. Copies of microfiches are fully satisfied with GOST 13. 301-7

The switching unit in the layout of the content and executive parts. The logical part provides processing of signals from sensors of mechanisms and memorization of operator commands from the control panel (type of original copy type).

A visualization is performed by a liquid electrophotographic developer in device 5 of the manifestation. When a device of development is developed on the counter electrode, a positive voltage is supplied from the source 7, which is switched on through the switching unit 1 by the incoming signal from the sensors of the movement mechanism 11. A positive voltage at the counter electrode increases the optical density of the negative copy. After the residue is developed and evaporated, the copy is obtained with a visible image.

The commutation of the voltage signs is given in table. one.

Table

The pre-regulation of voltages is carried out by resistor dividers installed in the switching units along the input circuit of the power sources. This adjustment can be made on the output circuit of the sources. The installation of the divide in the switches, power supplies, or the charging and display devices themselves is not essential and is determined by design considerations.

As billet microfiche used. A lavsan film with a thickness of 1OO200 µm is coated with a conductive thin nickel underlayer and a layer with a thickness of 3 µm of an organic polyepoxypropylcarbazole photoelectric semiconductor sensitized with trinitrofluorone. Exposure is carried out in a contact way for 2-10 with a lamp of the type KGM 12

100, the development of latent electrostatic imaging is carried out by a liquid developer based on freon ZIZ. The developer includes soot, as well as oils and surfactants. The particle count particle yield is positive ..

For example, when copying is copied in a positive-positive way, using the commution block 1 and the switches, negative voltages of -7 kV-300 V are applied to the charging device and a negative voltage of -150 V to the counter electrode of the manifestation device. The values of these voltages are preset by adjusting the power supply source.

Different voltages on the scorotron grid (-300 V and +250 V) are explained by the fact that EFS has a different ability to charge with a positive and negative sign at the same time and intensity of charging. The charging conditions are chosen so that the potential of the layer is 1 V ty-200 V. The efficiency of the apparatus is that it allows you to copy any of the four possible options: positive negative, positive negative, negative positive, negative negative . Wherein; By changing the polarity of the charge and the conditions of the development carried out by the switches and the switching unit. Any type of copying is done on the same electrophotographic screen with the same manufacturer.

The proposed apparatus fully realizes the possibility of unifying consumables for all copying schemes, which is unattainable in ordinary photography.

eight

Two switches are used to control the switch unit. One toggle switch indicates the type of input microfiche (negative-positive), and the second one indicates: a hygienic copy of the microfiche (negative-positive) l. The selected modes of the layout are given in Table 2,,

.,., ...,

Table 2

The technical efficiency of the device is determined by the simplicity of its maintenance and the relatively low cost of consumable electrographic materials that are not containing the scarce silver.

The device simultaneously replaces photo diazoduplicators, as in the existing devices on the photo and visual processes it is possible to copy only with reversal of the image (for example, negative-positive), and the diazoprocess ensures copying only without inversion (for example, n: negative-negative).

Claims (4)

Invention Formula 1, an electrophotographic copying apparatus containing a charging device, a development unit with nx power sources, an exposure unit, in which, in order to enhance its functionality, it is equipped with a switching unit and two switches This switching unit is connected to the exposure unit and switch inputs, one switch is connected to the charging device and its power source, and the second to the developing unit and its power source, 2, The device is in accordance with claim 1, 1 and 2, and so that, in order to automatically switch from copying positive images of negative signals and vice versa, the output of the photosensor is connected to the input of the switching unit. Sources of information accepted in examination at examination 1. USSR author's certificate No. 5O32bO, cl. q OZ G 5/06, 1976. IS -4f PTI 5 2. US Patent No. 398О404, cl. 355-10, 1976. 3. US patent number 4003650, class. 355-14, 1977. 4. US patent Na 3951541, cl. 355-8, 1Y76 (prototype)