DE7016463U - DEVICE FOR RECHARGING ELECTROPHOTOGRAPHIC MATERIALS. - Google Patents

Description

ELBE-KAMERA-GESELLSCHAFT Dresden, June 17, 1970

LIMITED LIABILITY Li / Kcw.

Subject: Gm application no.G 70

Facility for loading electrophotographic

Material η

The invention relates to a device for charging electrophotographic Layers by means of a corona discharge.

The following requirements must be placed on facilities of this type:

1. High efficiency in terms of useful electricity yield and charging speed;

2. -Regular and E-producabsit;

3. constructive simplicity;

4. Protection of the electrophotographic material from damage or overloading due to hoclispaniiing rollover.

Charging devices of this type were known as u? N ~ ^T , <_. · Corotron (US Pat. 2,777,957) and Corotron (US Pat,. ^ 36,725), in which at least one thin,. The wire that can be laid at high voltage is partially surrounded by a clad metal screen and transfers charge carriers to an electrophotographic layer that is passed along the wire.

Although the Scorotron fulfills the requirements mentioned under 2) and 4) very well, it is relatively complex in terms of construction and due to insufficient usable atom yield for high Loading speeds not suitable. The corotron that satisfies the requirements mentioned under 3) and 4) well Claims under 1) and 2) are insufficient.

7016463 10/29/70

The purpose of the invention is to improve such charging electrodes to achieve.

The object of the invention is to provide a device for charging ElektrophotoFjraphiach he ochichten to create the constructive Simplicity and rollover safety adjustable i3t and due to an increased Ναι. zstroma us prey a high loading speed guaranteed.

According to the invention, this task becomes / n in a facility Charging, in which at least one corona discharge wire that can be connected to high voltage is partially covered by a conductive screen is surrounded, solved in that the screen has a leakage resistor with ground potential or with the potential of the back of the recording material connected i3t. The leakage resistance can be a high resistance adjustable V / resistance are formed. However, it can also be selected from several high-ohmic i'est resistors. The .Vert of the respectively effective Leakage resistance i3t the type of the drawing meter i'ils and / or the charging speed, the level of the high voltage, the shape and dimensions of the screen and its spacing to the layer to be charged, the prevailing atmospheric conditions and the changing exposure intensity of the photoconductive layer conformable. Is in a well-known way on both sides of the photoconductive layer a corrugation path arranged, then each screen can optionally be connected to a leakage resistance of a certain V / resistance value.

The device according to the invention greatly increases the effectiveness of the charging electrode by increasing the ratio of the for the charging of directly used electricity back to total electricity is shifted in favor of the former, without the need for a high voltage increase with the associated disadvantages. The facility meets all of the requirements mentioned under 1) to 4).

The invention is explained below on the basis of exemplary embodiments explained.

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^ s lines:

i''ic · 1 charging device with ochirm discharge resistor'jnd Fir. 2 Loading device for zinc oxide papers

I-'ig. 3 Effectiveness of the charging device with different Shield discharge resistors were standing.

ue.v'ß i''i; -. 1 is well known within an electrical Leitfiihijen Schirmes T is suspended from a corona wire 2, which is connected to an Iiochspannungagerat 3 is in connection. The screen 1 iat via an adjustable bleeder resistor 4 with Maase potential tied together. At the charging device, a photoconductive layer 6 located on a carrier 5 is used for the purpose of charging passed in a familiar way.

According to -Pig. 2 are 3 on both sides with a zinc oxide 3 layer 7 provided carrier 8 each a U-shaped ochirm 9, 10 arranged, in which 3ich two parallel lying each for the purpose of increasing the charging current Corona wires 11, 12 and 13, 14 are located. The corona wires 11, 12 are at positive high voltage of a certain level and the coron wires 13 »14 at negative high voltage of a different magnitude. The ochirm 9 is via a switch 15 either via one of the Leakage resistors 16 or 17 can be connected to ground potential; the Screen 10 is also connected to ground via one of the discharge resistors 18 or 19 in the illustrated embodiment.

The way it works is as follows:

After the corona discharge has ignited, some of the charge carriers try to to flow off via the screen 1. The bleeder resistor 4 complicates and reduces this outflow. As a result of the The charge carrier reaching the screen is assumed by the screen 1 between ground potential and that applied to the corona wire 2 Potential at high voltage. This shield potential differs from the ground potential all the more, the greater it is the value of the bleeder resistor is 4. This ochirmpotential has the effect that the total discharge current is reduced;

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■ \ Ό '-, χ at the same time, the ratio of the useful discharge current (the current that reaches the photo-conductive ^: -'hi; that the value of the utility Ll ': de3trome3 increases until a saturation value is reached. i''ig. 3 illustrates these relationships. The attracted curve represents the proportion dea Hutzatromes represents the üesamtsxrom, while the dotted curve characterizes the Nutzladeatrom and the dash-dotted curve Jen course of the ^above eaamtstromes depending on the value of the Ab'leitwiderstandes.

Since with a stone '.7ert dea leakage resistancea and consequently with increasing shield potential the protective function de3 shield a with regard to flashovers between the screen and the recording material on the one hand and screen and grounded parts dea On the other hand, the device drops, the value of the bleeder resistance a 4 must be optimized with regard to requirements 1) and 4) will. The optimum value dea bleeder resistance a 4 depends on the recording material, the loading speed, the level of the High voltage, the shape and dimensions of the screen and its distance from the material to be charged, the atmospheric Conditions and on the intensity of the exposure of the photoconductive layer 6 depending. That means changes the named parameters influencing the charging can be taken into account to a certain extent by simply adjusting the bleeder resistor 4. E.g. when using different recording materials the Maintain the charging speed and the level of the high voltage if the different sensitivity of this Materials by changing the bleeder resistance 4 is taken into account.

AIa leakage resistance can be infinitely adjustable Variable resistor 4, or several optionally switchable fixed resistors - as in Fig. 2 - can be used. Although the charging device for zinc oxide papers has a corona discharge path on both sides of the photoconductive layer 7 is present, changes to the behavior of the shield discharge according to the invention via a resistor not a.

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Ds the level of the high voltage applied to the corona wires 11, 12 differs from the one on the corona wires 13-14, it can be advantageous for the purpose of achieving optimal isolation ratios be to give the leakage resistors 18,19 other .ytes as the derivative id 16, 17-

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Claims (5)

- 6 S - :: '"jumpers: 1. A device ziun charging electrophotographic layers with at least one Corrnaertladungsstrecke, wherein at least one legbarer to high voltage corona wire is partially umgebsn by a conductive shield vi hich, dad-ir ^ h. characterized in that the screen (1; 9; 10) has at least one discharge resistor. -d (4; 1S; 18) can be connected to the ground potential of the device or to the potential of the rear side of the layer (6; 7). 2. Device according to claim 1, characterized in that dnß the 7 / ert of the respective effective leakage resistance changes the parameters influencing the charging adaptable is. 3. Device according to claims 1 and 2, characterized in that that in a known manner on both sides of the layer (7) to be charged a corona discharge path is arranged, of which each screen (9; 10) is optionally determined with at least one bleeder resistor (16; 18) V / resistance value is connectable. 4. Device according to claim 1, characterized in that the leakage resistance of a hochohjnigen adjustable η V / ider3tand (4) is formed. 5. Device according to claim 1, characterized in that the leakage resistor from a group of high-resistance fixed resistors (16,17; 13; 19) can be selected. ELBE CAMERA SOCIETY with limited liability 7O16463? 9.io.7n