JPS595890B2 - electrostatic copying machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flash discharge tube used for exposing an original or fusing a toner image to a final copy, and a device for supplying power to the flash discharge tube during discharge and for maintenance. The present invention relates to an electrostatographic reproduction apparatus having an array of capacitors which is easily accessible by opening a cover member or which is disposed on a rack of the apparatus.

It has become increasingly common in electrostatographic reproduction machines to use flash discharge tubes both for exposing the original image and for fusing the toner image to the final copy carrier.

This makes it possible, inter alia, to expose a still original onto a continuously moving copy carrier without the use of optical tracking devices, without the exposure time reaching a period that would result in unacceptable blurring. For example, West German Patent Application Publication No. 10630
As described in No. 29, when a flash discharge tube is used to fix a toner image, the amount of labor required to fuse the toner image within a short period of time is such that the heat generated in the toner is not transferred to the paper much. can be added.

This selective fusing method saves energy and greatly contributes to careful handling of the copy support. Since in both cases a large amount of energy must be applied to achieve the desired effect during the short time available for irradiation, the flash discharge capacitors required for this can be removed from the device for convenience of maintenance. They are often located in their own racks and pose a significant danger to maintenance personnel who open the outer cover of the equipment even after the power has been turned off. According to the invention, therefore, the cover member or the fastening element which fastens the reproduction apparatus rack to the apparatus controls a safety switch which causes a rapid discharge of the capacitor string via a current limiting resistor.

Preferably, the safety switch is controlled by a set screw of the cover part or of the rack, in which case the set screw which releases the cover part or of the rack only after a few turns interacts with the operating element of the safety switch, and the releasing movement of the set screw is controlled by the set screw. The switch is already released at the start of the process. This forces a fast discharge of the capacitor via the current-limiting resistor even when opening the copying device cover, which shields the outside of the capacitor and prevents it from being touched. Since this is already done during the first unscrewing of the screw, which releases the rack only after a few turns, at least at least one of This ensures that the discharge is completed to a harmless voltage value. To further prevent electric shock during maintenance and repair of capacitors, a power circuit breaker is provided which is maintained by a back-contact control holding circuit in the connected state which disconnects the power connection as a result of operation of the operating switch in question or failure of the equipment. There is.

The power circuit breaker has an auxiliary buck contact that closes when the circuit breaker blows and shorts the capacitor string through a current limiting resistor. Since all experienced maintenance personnel unplug the power supply before starting work inside the equipment, the above measures greatly reduce the probability of forgetting to discharge the capacitor before starting maintenance work. Moreover, due to power outages or malfunctions, personnel may mistakenly work on the inside of the device without first turning off the power, or the outage may begin to such an extent that personnel no longer consider that the capacitor array may still be charged. Even when it takes time, the above measures will be effective. A particularly convenient configuration of the above-mentioned double safety device of the capacitor array results if there is a safety switch in the holding circuit of the power supply circuit breaker which causes a rapid discharge of the capacitor array as a result of release of the fixing element of the reproduction apparatus rack.

Another safety device according to the invention, which operates in particular if the capacitor bank happens to be recharged after the release of the fixing element and possibly even after the removal of the rack from the device has already begun, is:
A safety switch arranged on the rack carrying the capacitor array is provided with a further safety device, and as a result of removal of the rack, this safety device, via another current-limiting resistor also arranged on the rack itself, This is to short-circuit the columns. In either case, the capacitor string is 0.1 seconds or 1
．． The current limiting resistor is sized to discharge with a time constant of 0 seconds, and the capacitor string is first short-circuited through the fixedly connected discharge resistor, which forms a discharge circuit with a time constant of a few minutes. It is preferable to do so.

A time constant in the range of 0.1 seconds to 1.0 seconds generally ensures a sufficiently rapid discharge such that unacceptably high discharge currents do not occur.

The continuously connected discharge resistor has a relatively high time constant so that it does not interfere with the normal functioning of the device and is sufficient to ensure that the capacitance is discharged, at least after a relatively long period of non-use. According to another preferred feature of the invention, the flash discharge tube is switched off when the device is switched off, in order to protect the safety switch in normal cases and also to allow a safe discharge of the capacitance via the flash discharge tube in general. A control device for ignition is provided.

Since the flash energy required for the purposes mentioned at the outset is relatively high, a single capacitor is usually not sufficient for powering the flash discharge tube.

According to a preferred feature of the principles of the invention, the capacitor string is therefore divided into at least two partial capacitors, and a circuit for comparing the instantaneous voltage levels or instantaneous charging currents of the partial capacitors is coupled to a charging control device for the capacitor string, If a difference appears, the charging process is delayed or interrupted. This avoids overloading the charging circuit due to asymmetric charging and also indicates failure of individual capacitors before major damage occurs. Also preferably connected to the circuit of the capacitor string or to the circuit of the individual capacitors and in parallel thereto is a measuring adapter for the safe measurement of the charging voltage and a Zener diode or The incandescent bulb limits the voltage through the adjacent measuring points.

In this way, the maximum possible measuring voltage is limited to a very small value, which is approximately determined by the ratio of the incandescent voltage or the internal resistance of the Zener diode to the current limiting resistor. When no meter is connected, the incandescent light serves as an optical indicator of the state of charge of the capacitor string. According to a preferred embodiment of the invention, the capacitor array, together with the flash discharge tube and the feeding and guiding device for the copy support covered with the powder image to be fixed, is a rack that can be removed from the reproduction machine as a unit. It is located in A cooling air passage is preferably provided which communicates with the condenser chamber when the rack is in use. When using discharge tubes that are powered by a capacitor array and used for flash fixing, long energy supply paths with cutting points are avoided in this way.

Under the aforementioned high flash powers, even a simple plug-in of the original discharge circuit, which has a transient resistance of a few tenths of an ohm,
This may result in a loss of about 10 to 20% of the usable discharge energy. Despite the high flash energies that are problematic in this case, sufficient cooling of the condenser is ensured by the automatic connection of the cooling system of the device. In particular, if an electrolytic capacitor is used, its operating temperature should not exceed a temperature of about 80° C. anywhere inside the capacitor. This means that the external temperature of the jacket must be kept as low as possible below approximately 40°C. To accomplish this, a relatively large flow of cold air must be passed through the condenser chamber. For the reasons mentioned above, a flash discharge tube placed in the same rack as a capacitor also generates significant heat.

In that case, it must be noted that the operating temperature of the flash discharge tube is much higher than that of the capacitor. Also, the cooling air flow, unlike the cooling air emanating from the condenser chamber, may be accompanied by gases and vapors generated during intense irradiation of the toner powder to be fixed. This cooling air stream therefore has to pass through a filter, which necessarily limits the feed rate. According to the invention, a flash discharge tube used for exposing the original or fusing the toner image to the final copy carrier is provided, and the flash discharge tube is energized during discharge and after the device cover member is opened for maintenance. In an electrostatographic apparatus with an array of capacitors that is easily accessible or arranged on a rack of the apparatus, the cover member or the rack of the apparatus is fixed to the apparatus by a fixing element that can be rotated or displaced manually. and said rotatable or displaceable fixing element is provided with a safety switch that causes a rapid discharge of the capacitor string via a current limiting resistor and a method such that release of said fixation closes the discharge circuit. A copying apparatus is provided, characterized in that the copying apparatuses are connected to each other.

According to another characteristic of the invention, therefore, separate cooling air channels are provided for the condenser chamber and the reflector chamber of the rack, in which case the cooling air channel connected to the reflector chamber is provided with Connect a carbon filter for cooling air near the reflector.

In another embodiment of the invention, a lid cover is provided which shields the reproduction apparatus rack from the outside in the use position, and includes a copy support guide path curved piece for deflecting the copy support downward in the use position of the lid cover. do.

The operating element of the safety switch, which is easily arranged, is arranged on this lid cover. In a preferred embodiment of the present invention, the electrical switching element taken out from the copying machine together with the rack is
It is attached to a flap that is rotated out of the rack for maintenance and inspection of the above-mentioned switching element in the connected state.

Preferably, the electrical switching element and unit arranged on the rack are connected to the electrical switching element and unit on the copying machine side by means of a plug which engages upon insertion of the rack, as is known per se. According to another advantageous feature of the invention, the individual capacitors of the capacitor bank are arranged in parallel grids in the cooling air stream, and supports surrounding the ends of the capacitors are provided. held by a rod. Preferably in this case, the capacitor array consists of electrolytic capacitors, the support bar on the side of the electrolyte outlet is provided with a support device for the protective membrane, and the connecting wires of the capacitors are parallel to and inside the support bar. is passing through. Preferably, the capacitor array consists of cup-shaped capacitors, the outer dimensions of which have a diameter-length ratio greater than a 1:3 ratio. A lattice array of condensers in elongated structures paralleled across the cooling air flow provides optimal heat transfer between the condenser and the cooling air.
This ensures optimum utilization of the cooling air by the condenser used with high power.

In this case, there is no possibility that a temperature exceeding the effective operating temperature of about 80° C. will occur even in the innermost part of the electrolyte. The supporting rods placed on the front side of the capacitor for a good arrangement of cooling air also carry a protective film that prevents the electrolyte from blowing out from the safety valve of the capacitor, so that it is not necessary to place it in the vicinity of high power capacitors in the rack. At the same time, the installed electrical units are well protected with low production costs. Embodiments of the invention are shown by way of example in the drawings.

According to FIGS. 1 and 2, on the bottom 1 of the housing,
There is a U-shaped housing 2 of the irradiation fixing device which can be removed as a single unit 20 from the housing 3 of the device.

A capacitor row consisting of four capacitors 5 is arranged on a support rod 4 inside the housing 2. Further, a reflector 6 is fixed between the side walls of the U-shaped housing 2, and a flash discharge tube 8 is disposed in a holder 7 therein. A guide wire 9 is strung across the lower opening of the reflector 6 to prevent contact between the flash tube 8 and the copy carrier 21 being fed through the fixing table in the direction of arrow A.

A pivotable guide plate 10 for the copy finger 21 to be fixed is arranged below the guide wire 9. Information board 1
0 is supported on an axle 11 and is pressed against a stop 13 by a spring 12 in the position of use. This guide plate can be pivoted downwards in the direction of arrow B in order to remove the inserted copy carrier 21 if necessary. The guide plate then becomes parallel to the bottom partition 14 which separates the condenser and reflector chambers of the rack 20. The condenser chamber of the rack 20 is connected to the wall 15 through the lateral opening 2a of the housing 20.
It communicates with ventilation passages 120 and 121 constituted by 1 to 19.

For this purpose, the walls 15 and 16 have openings 15a and 16a, which coincide with the opening 2a of the rack in its position of use. The condenser chamber also communicates with the vent 1 in the housing bottom 1 via the opening 2b. A ventilator 22 is arranged in the housing bottom 1. Ventilators draw in cold air from outside. Cold air is condenser 5
It is then passed through passages 120 and 121 to other equipment rooms to be cooled, such as electronic equipment rooms. The condenser cooling air is therefore drawn in directly from the outside and is not taken from the cooling air stream which is already somewhat preheated there, depending on the circumstances, coming from inside the device. This is because high power capacitor strings require particularly effective cooling. A grid 84 attached to the vent 1a prevents contact with the ventilator 22 or the capacitor row 5 behind it. The cooling air passages 124, 125 defined by the walls 15 to 19 and the midsole 23 communicate with the reflector chamber of the rack via the openings 15b, 16b of the walls 15, 16 and the opening 2c of the rack 20.

The passage 124 itself communicates via the opening 23a with a cooling air chamber 126 from the inside of the device, for example from an electronics room. This passage delivers slightly preheated air. An opening 17a in the wall 17 leads from a passage 125 to an air passage 128 which the wall 17 forms together with another wall 27. This air passage 1
A ventilator 29 and a carbon filter 30 are disposed within 28. The ventilator 29 thus sucks slightly preheated air from inside the device through the reflector chamber, over the surface of the copy carrier to be fixed, and then through the carbon filter 30 to an outlet provided with an oblique guide surface. It is discharged to the outside through the slit 3b. As a result of the insertion of the carbon filter, the cooling air flowing through the reflector chamber is free from ozone, which is sometimes generated around the flashlight during intense flash exposure, and from the decomposition of developer components, causing damage to the individual plastic components. The plastic vapor generated by the process is removed. By dividing the rack 20 into two separate ventilation zones, the condenser chamber is optimally cooled and the reflector chamber is optimally freed from gases harmful to health, in which case the rack Due to the above-described spatial interrelationship between the cooling air openings and the passages, the proper cooling air connection is automatically made when the rack is inserted.

In this way, both the capacitor and the flashlight can be arranged in the same rack for quick and easy maintenance. To secure the rack 20 in the position of use, the device opening for inserting the rack is closed with a lid cover 31.

This lid cover is suspended by a trunnion 32 to an upwardly open hook 33 of the housing 3 of the device, and its upper end is screwed to the housing 33 by a screw 34. screw 3
4 protrudes somewhat into the housing when tightened,
Then, operate the operating lever 35 of the safety switch S1.

The function of the safety switch S1 will be explained in detail on the basis of the wiring diagram shown in FIG. The screw 34, which is held in the inserted position by the backing plate 36, is prevented from falling out by the safety ring 37 when the lid cover 31 is opened or removed.
Once the screws 34 are removed, the lid cover 31 can be rotated out of the device in the direction of arrow C, and then the shaft piece 32 can be pulled upward from the hook 33 and removed.

The rack 20 is now released and can be pulled out of the device by grasping the handle 38 attached to the rack. However, when the lid cover 31 was already turned in the direction of arrow C, due to the overhang 31a of the lid cover 31,
The operating element 39 for opening the rack-mounted safety switch S2 or S3 is already opened. The function of the safety switch S2 or S3 will also be explained in more detail below with reference to the wiring diagram in FIG. Finally, the lid cover 31 is further formed with flat-edge projections 31b and 31c, the mutually facing surfaces 31d and 31e forming a downwardly curved guide path for the copy carrier 21 to emerge from the fixing table. do.

As a result of this construction of the guideway, when the lid cover 31 is closed or when the rack is ready for use, the direct light of the flash discharge tube 8 leaks out, where it can cause eye damage to the attendant during a high-energy flash discharge. There is no risk of causing In addition, a curved light-shielding plate 85 is provided on the entry side of the copy body, and it captures the scattered light directed toward the photoconducting cylinder, and also serves as a guide plate for the advancing copy body 21. do. Overhang 3
A pair of feed rolls 40, 42 are supported in the notches 1b and 31c, and the shaft 41 of the feed roll 40, which rests on the copy carrier due to its own weight, is inserted into the elongated hole 31e of the overhang 31c.
Accordingly, the shaft 43 of the feed roll 42 is supported by the hole 31d of the overhang 31c. Shaft 4 of driven roll 42
A gear 44 is fixed to 3 and meshes with a drive gear 45 fixed to the device. When the lid cover 31 is inserted, the two gears automatically engage. The two rolls also constitute another safety device against the escape of scattered light and, for electrostatic discharge of the ejected copy carrier, are provided with at least some electrically conductive coating, for example an electrically conductive elastomer, and are electrically conductive to one another. combined.

A plate 91 that can swing about an axis 90 serves as a support for the switching element that remains in the rack when the rack 20 is removed from the device.
is provided, and is held on a receiving plate 93 by a stop spring 92 when in use.

When rotating the plate 91, the electronic switching element remains connected to the rack by the flexible conductor 94. According to FIG. 3, a power circuit breaker is connected to wires 46, 47 which can be plugged into a power source.

The power supply circuit breaker 48 includes two make contacts 48a and 48b, as well as a holding contact 48c and a back contact 48d. A button T1 for connecting the device and a button T2 for disconnecting the operation of the device are connected to the holding circuit of the circuit breaker 48.
Further, the power circuit breaker 48 can be turned off by the switch S1 also shown in FIG. During normal use of the device, the switch S1 is closed by a screw 34 (FIG. 1) that holds the lid cover 31. Circuit breaker contact 48
When electric wires 46 and 47 are connected by a and 48b, changeover switches S2 and S3 connect diodes Dl and D2 and capacitor 5 to cut off one phase of the power supply current, respectively, for the state shown in the drawing. If it is in the position to join,
The capacitance 5 can be charged via these diodes.

Switches S2 and S3 are placed in the above-mentioned connection position, as can be seen in FIG. 1, by means of the overhang 31a of the lid cover 31 when the lid cover 31 is closed, allowing charging of the capacitors 5a, 5b. Switch S2 clearly shown in Figure 3
, S3 position, that is, when the lid cover in Fig. 1 is opened,
Capacitor 5 is short-circuited via current limiting resistors R and R2. 0.1 seconds to 1.0 seconds for discharge of capacity 5
The resistors R1 and R2 are sized to obtain a time constant of seconds. Connecting current limiting resistors R3 and R4 and closing back contact 48d of circuit breaker 48 creates another discharge circuit with a time constant of 0.1 seconds to 1.0 seconds. Furthermore, discharge resistors R5 and R are connected to the capacitor circuit.
6, the capacitors 5a and 5b are stably discharged with a time constant of several minutes. A trigger transistor TRl driven by a control circuit 49 via a control line 153 is connected to the power supply line to control charging of the capacitor array 5. The control circuit 49 includes, for example, our West German patent application P2.
634396.4 can be used. In this configuration, the trigger transistor is driven according to the instantaneous voltage of the capacitor with special phase shift control, producing charging current pulses of approximately the same amplitude. In order to further equalize the charging current, a low loss iron core choke 50 is provided as a reactance. Charging control is further improved by the present invention as follows.

That is, a voltage divider consisting of two resistors R7, R8 is connected at the point which carries the total positive or negative voltage of the capacitors 5a and 5b. If the charges of the capacitors 5a and 5b are equal in opposite directions, the line piece 51 connecting the two resistors R7, R8 must be on average at the level of the line 46 forming the reference point. The conductor piece 51 is connected to two Zener diodes Z1 and Z2 or a capacitor 52 in opposite directions.
Although its role will be described in detail later, it is coupled to the control line 53 via another control circuit including two crossed transistors TR2 and TR7.

When the control line 53 conducts current, the charging control device 4 is connected so that the charging of the capacitor 5 is interrupted or at least delayed.
interfere with 9. While the Zener diodes Zl and Z2 are cut off, that is, when the voltage between the conductor 51 and the conductor 46 is momentarily smaller than the Zener voltage of the Zener diode applied in the opposite direction, the capacitor 5 is charged intermittently. The resulting voltage change is differentiated by the capacitor 52.

A current corresponding to the derivative of the voltage change on capacitor 5 caused by the individual charging process therefore flows through resistor R9. When the instantaneous voltage across resistor R exceeds the threshold of transistors TR6, TR7, one of these transistors becomes conductive depending on the polarity of the voltage across R9, causing current to flow through conductor 53. This current interferes with the charging control device 49 so that the two capacitors 5a and 5b are charged simultaneously. When the voltage difference between conductor 51 and conductor 46 is large enough to destroy one Zener diode, one of transistors TR6 and TR7 is controlled so that charging is stopped. The resistor RlO is necessary for symmetry reasons. A rheostat Rll is further provided between the neutral wire 46 and one of the power supply lines 60 and 61 of the capacitor 5, and a resistor Rll is connected via a conductive wire piece 62.
12 and R13 and is coupled to a subsequent resistor string connected to the neutral conductor 46.

One end of this series of resistors is connected to a reference potential +Uv, for example +4V.
It is in. There is an emitter of an Npn transistor TR2 in the coupling line 62 between the rheostat Rll and the auxiliary resistor string;
Its base is on the neutral wire 46 and the collector is on the control wire 53
is combined with By adjusting the resistor Rl, the base of the transistor TR2 becomes positive with respect to its emitter at various heights of negative voltage on the supply line 60 of capacitance 5,
A control current therefore begins to flow through the collector and is routed to the control circuit 49 via the control line 53 so that the charging process is interrupted.
interfere with With this wiring, two capacitors 5
The charge level of one of the capacitors is regulated, the charge level of the other capacitor being kept at the same level by the aforementioned control circuit, which also acts on the control circuit 49, which monitors the symmetry of the charge. In that case, two diodes D3
and D4 prevent mutual interference of two circuits operating via the same control line. Trigger transistor TR3 is used for igniting flash discharge tube 8 and triggers the discharge of capacitor 63.

This capacitor 63 supplies power to the primary side of an ignition transformer 64 . Its secondary side generates the ignition voltage for the ignition electrode 65.
Charging of capacitor 63 to the appropriate voltage level is accomplished by resistor R.
This is done via l4. Trigger transistor TR3
itself is driven by transistor TR4.

Transistor TR4 becomes high ohmic when the base voltage disappears. Transistor TR4 is driven by a control line 58 which couples it to a suitable control device 59 of the device. The control device 58 of the device is, for example, according to West German Patent Publication No. 204668.
The control line 58 may be of the type described in No. 1, thereby causing the control line 58 to die at the end of a single or multiple copying cycle, or as a result of equipment failure, thereby causing the control line 58 to die at the end of the copying process, or as a result of a failure. In this case, the flash discharge tube 8 is caused to discharge. Capacitor 66 is thus charged via resistor Rl5. When the voltage on the capacitor 66 reaches the breakdown voltage of the trigger diode TR5, the trigger diode becomes conductive at low ohms, so the capacitor 66 is discharged through the resistance in the control section of the trigger transistor TR3, and the trigger diode TR5 becomes conductive. Transistor TR3 also becomes conductive. Resistor R15 and capacitor 66 are sized such that the cut-off time of trigger transistor TR4 before breakdown of trigger diode TR is longer than half a wavelength of the power supply. In this way, the trigger can be activated before the discharge lamp is lit.
It is ensured that transistor TRl is turned off. A reaction of the discharge process to the power supply is thereby avoided. The control 49 of the copying device is activated not only at the end of each copying process, for example activated by a start button, but also when a copy carrier is inserted into the fixing table or when the paper reserve is exhausted. A safety switch activates, for example, when the toner reserve runs out, the cleaning fleece runs out, or when the device cover is opened.
Further improvements can be made in a known manner.

The above-mentioned reproduction device controls include conductors that are destroyed when the reproduction device is stopped, such as the power supply lines of the drive motor or the electromagnetic coupling.

A control line 58 and another control line 67 leading to the charging control device 49 are connected to this conductor. The latter causes the capacitor 5 to charge further while no shutdown of the device occurs. The reproduction machine controller may also include a timed switch. This timed switch causes multiple firings and recharges of the flash discharge tube in a specific rhythm after activation of the irradiation fixing device so that large areas of the continuously moved copy carrier can be irradiated. let Finally capacitors 5a and 5
A measurement adapter is connected to the circuit b.

This adapter consists on the one hand of a series of auxiliary resistors Rl6, Rl7 and an incandescent lamp 60, 61 connected therebetween, and on the other hand of a series of auxiliary resistors R18, R, 9 and a Zener diode Z3 connected therebetween. Measuring plugs 70, 71 are arranged before and after the section bridged by the incandescent lamps 60, 61 or the Zener diode Z1, to which the measuring device 1 can be connected. In that case, the incandescent bulbs 60, 61 or Zener diode Z1 connected between
In combination with current limiting resistors Rl6 to R,,
Ensure that the maximum voltage of the measuring device does not exceed the breakdown voltage of the incandescent bulb or Zener diode. test jack 70
or 71, when the measuring device 1 is not connected, a small current flows through the incandescent bulb or Zener diode. At this stage of use, the presence of voltage across the capacitor is detected by the incandescent bulb 68.
, 69 can also be visually confirmed. The measuring device 1 with relatively low internal resistance is connected to the test jack 70 or 7.
1, the voltage passing through the incandescent lamps 68, 69 or the Zener diode Z3 is immediately extinguished. Since a current flow proportional to the voltage on the capacitor takes place only through the measuring device, with appropriate calibration this current flow can be indicative of the voltage present on the capacitor 5. Finally, dashed lines 57 in FIG. 3 indicate which of the components shown in the wiring diagram are arranged in the flash lamp rack 20, which can be removed from the apparatus as a single unit. The connection of said switching elements to the remaining switching elements of the device is carried out by connection plugs 74 to 80. These connection plugs are arranged in a known manner in the rack in such a way that an electrical connection is automatically established when the rack is inserted into the device. 4 and 5 show the support of the individual capacitors 5a, 5b of the capacitor array 5. FIG.

In that case, it is preferred that the end of the cup of an aluminum electrolytic capacitor used for powering the high-power flash discharge tube is fixed to the notch 4a of the support rod 4, and the support rod 4 is connected by a tightening bolt 81. A hook 4b is provided protruding from the lower side of the support rod 4, and is inserted into the hole 2 of the housing 2 of the rack 20.
d. The diameter of hole 2d is the distance between the hooks.
The size is such that the hook 4b can be inserted straight through the hole as long as the gap between the holes coincides with each other. When the tightening bolt 80 is tightened, the hook 4b catches behind the wall 2 of the housing and thus connects the support rod 4 and the rack 20. An annular groove 4c is further formed in the support rod 4 at the head side end of the capacitor, and after connecting the capacitor, this annular groove 4c is formed.
A membrane 83 of elastic plastic or the like can be inserted therein.

This membrane is used for example as a safety valve 82 provided in each electrolytic capacitor.
This prevents the electrolyte blown from the capacitor from spreading into the interior of the rack 20 and damaging the electronic switching elements mounted on the plate 91 (FIG. 1), especially in the vicinity of the capacitor. To enable the insertion of the membrane 83, the feed lines to the capacitors 5a, 5b are led out laterally, as can be seen in FIG. Fourth
The support for the capacitors 5a and 5b shown in FIG. Guaranteed to be easy.

Also, as a result of the elongated structure of the capacitor, heat generated within the capacitor can easily flow outward.

[Brief explanation of the drawing]

1 is a sectional view of a device according to the invention taken along line 1--1 in FIG. 2; FIG. 2 is a sectional view of the device taken along line 1-- in FIG. 1; FIG. Figure 4 is a diagram of the capacitor support.
FIG. 5 shows a diagram of the connection terminals of the capacitor. 55... Capacitor row, 34... Fixed element, R3, R4... Current limiting resistor, S1.
...Safety switch.

Claims (1)

[Scope of Claims] 1. A flash discharge tube used for exposing an original image or fusing a toner image to a final copy carrier, and for supplying power to the flash discharge tube during discharge and opening a device cover member for maintenance. In an electrostatographic apparatus with a capacitor array, which is easily accessible or arranged on a rack of equipment, the cover member or rack of equipment is secured to the equipment by means of a fixing element 34 which can be manually rotated or displaced. It is fixed to
The rotatable or displaceable fixing element 34 is then connected to a safety switch S_1 which causes a rapid discharge of the capacitor array 5 via the current limiting resistors R_3, R_4 and which, upon release of said fixation, closes the discharge circuit. A copying apparatus characterized in that the reproduction apparatus is connected by a method. 2. The safety switch S_1 is controlled by a set screw 34 of the cover part or rack, in which case the set screw which releases the cover part or rack only after several turns interacts with the actuating element 35 of the safety switch S_1 and the set screw 2. The copying apparatus according to claim 1, wherein the switch is opened already at the start of the release movement of the copying apparatus. 3. As a result of operation of the operating switch in question or as a result of a failure of the device, a power supply circuit breaker 48 is provided which disconnects the power supply connection and which in the connected state is held by a holding circuit controlled by a back contact 48c. Yes, and this power circuit breaker has an auxiliary back contact 48d that closes when the circuit breaker disconnects, and the back contact 48d is connected to current limiting resistors R_3, R_4.
3. The copying apparatus according to claim 1, wherein the capacitor array 5 is short-circuited through the capacitor array 5. 4. Any one of claims 1 to 3, characterized in that the safety switch S_1, which causes a rapid discharge of the capacitor bank 5 as a result of the release of the fixing element 34, is located in the holding circuit of the power supply circuit breaker 48. Copying device described in the section. 5. Another safety switch S_2, S_3 is provided which is arranged on the rack 20 carrying the capacitor array, and the rack 2
0 from the device, these safety switches S_2, S_3 short-circuit the capacitor string 5 via another current-limiting resistor R_1, R_2, which is also arranged in the rack. The copying apparatus according to item 1. 6. Current limiting resistors R_1 to R_4 are sized so that the capacitor array 5 is discharged with a time constant of 0.1 seconds to 1.0 seconds. The copying apparatus according to any one of paragraphs 1 and 5. 7 When the capacitor array 5 is fixedly connected, it may be auxiliary short-circuited via discharge resistors R_5 and R_6 arranged in the rack 20, and these constitute a discharge circuit with a time constant of several minutes. Claim 1 characterized in that
The copying apparatus according to any one of paragraphs 1 and 5. 8. The copying apparatus according to claim 1, further comprising a control device for igniting the flash discharge tube 8 when the apparatus is disconnected. 9. The capacitor array 5 has at least two partial capacitances 5a,
5b, and the circuit R_7, R_8, 51 which compares the instantaneous voltage level or instantaneous charging current of each partial capacitor.
2. A copying apparatus according to claim 1, wherein the capacitor array charging control device 49 is coupled to the capacitor array charging control device 49, and if a difference occurs, the charging process is delayed or cut off. 10 Circuit of capacitor row 5 or individual capacitor 5a
, 5b and in parallel thereto, a measuring adapter for safe measurement of the charging voltage is connected, a Zener diode Z_3 or an incandescent lamp 68, 69 cooperating with current-limiting resistors R_1_6 to R_1_8. 2. The copying apparatus according to claim 1, wherein the voltage passing through adjacent measurement points is limited by the voltage.