JPS61177168A - High voltage power source for copying machine - Google Patents

Abstract

PURPOSE:To reduce the size of a circuit and to decrease a cost by integrally molding a printed board arranged with low voltage parts, a transformer not placed on the board, an arcing protecting resistor, the back surface of a high voltage terminal insulating cover. CONSTITUTION:Low voltage parts such as a resistor 6, a capacitor 5, a diode are disposed on the front surface of a printed board 4, and electrically connected on the back surface. A ferrite core 1, a low-voltage winding 2, a high-voltage winding 3 (not shown) and an arcing protecting resistor 8 are disposed out of the board, and electrically connected. Further, a high voltage output terminal 9 is provided in an insulating cover 29. The board 4, the parts removed from the board 4, and the back surface of an insulating cover 29 are molded and integrated. Thus, a high voltage power source can be reduced to decrease the cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a high-voltage power supply device for a copying machine having a structure in which a high-voltage transformer and high-voltage electrical parts are partially molded.

Prior Art FIGS. 5A-5C show a molded block 2o of a type in which the output is taken out through terminals, in which a high-voltage transformer and high-voltage electric parts are integrally moiled with insulating resin. Figure 6a.

b is a sectional view showing this internal structure, in which the low voltage winding 2 is inserted into the inner surface of the high voltage winding 3, and the ferrite core 1 is inserted into this to form the high voltage transformer 13. Further, a capacitor 5, a discharge resistor 6, a diode 7, an arcing protection resistor 8, and an output terminal 9 are mounted on the printed wiring board 4 and electrically connected to the high voltage transformer 13 and the high voltage winding lead terminal 14.1.
It is electrically connected through 7. The output terminal 9 is inserted into and fixed to an insulating cover 10, and a part of this insulating cover 1o, a high voltage transformer 13, a printed wiring board 11, and all of the parts mounted thereon are covered with an insulating resin 12. A part of the mold block 20 is formed by molding.

7a to 7c show a mold block 2o of a type in which the output is taken out by a lead wire, in which an output lead wire 15 is used instead of the output terminal 9 and is inserted and fixed into an insulating cover 16.

Everything else is the same as the output terminal method. FIG. 8 is a diagram showing its internal structure. Note that 11 is a low potential terminal for inputting, controlling, and grounding the mold transformer.

FIG. 9 shows the printed wiring board 4 inside this mold block 20.
This is the pattern surface. 5-8 symbolizes electrical parts and indicates their electrical connection status, 11', 17', 14'
18 is the insertion connection part of each number of the terminal, 18 is the output terminal insertion connection part, and in the case of the output lead wire method, it is the output lead insertion connection part. However, the following text will all refer to the output terminal insertion connection section. 19 is an arcing protection resistance insertion connection part. This mold block corresponds to the part surrounded by the dashed line 1 of the mold block 2o of the high-voltage power supply device shown in FIG. This high-voltage power supply device is shown in Figure 11 (1-01
As shown in Figure 2, the mold block 20. Control circuit 21
, switching transistor 22, current detection circuit 23,
It is composed of a voltage detection circuit 24, an input connector 26, an output adjustment volume 26, a snubber circuit 27, and the like. still,
Figure 12 shows a half-wave rectification, constant voltage circuit for output. The current detection circuit 23 is used to detect overcurrent and take some kind of action. Also, Fig. 13 shows a half-wave rectification of O output, constant voltage method, Fig. 14 shows half-wave rectification of O output, constant current method, and Fig. 15 shows half-wave rectification of O output, constant current method, 1
Figure 6 shows a constant voltage method with voltage doubler rectification for both output waves (forward and flyback waves).

In addition, there are various circuit systems depending on combinations of ①O output classification, rectification method classification, constant voltage, and constant current method classification.

Here, as shown in Fig. 12, the output voltage is 1oKV (
When taking out the DC), each potential difference in the mold block 2o is determined by the output terminal insertion connection part 18, the arcing protection resistance insertion connection part 19, and the high voltage winding pull-out terminal insertion connection part 1.
4' is about 15 pθak KV, and the other high potential parts and low potential parts pe
The distance between ak and ak is about 10 and ■. The distance required for electrical insulation on the printed wiring board in such a molded transformer is 1 sKV 20 m, 10KV"a
It has been experimentally confirmed that it is 1ON at keak.

Therefore, a creepage distance of 20M is required between the output terminal insertion connection part 19 and the high voltage winding lead-out terminal insertion connection part 14' in FIG. 9a. On the other hand, the thickness limit of plastic materials commonly used as insulating resins that can withstand through insulation under continuous voltage application is peak p.
1.5 m at eaklsKV, 10KV
It has been confirmed that the distance is 1.0 Im, and if that part is made into a space and filled with insulating resin, the required insulation distance will be significantly reduced, and as a result, the mold block 2o can be significantly miniaturized. becomes. For this purpose, a method was considered to provide slits 28 in the printed wiring board 4 and fill them with insulating resin as shown in Figure 9. However, this method has a large number of slits 28, which reduces the mechanical strength of the printed wiring board 4. weakens,
In particular, when the insulating resin 12 is molded by injection molding, there is a problem that the printed wiring board 4 is deformed by the injection pressure, making it difficult to secure the insulation distance.

FIG. 10 shows a state in which electrical components are mounted on the back side of the patterned surface of the printed wiring board and soldered on the patterned surface. Fig. 10a shows an output terminal type, and Fig. 10 shows an output lead wire type.

The biggest problem with the structure above and beyond the problems to be solved by the invention is that the high-voltage winding lead-out terminal insertion connection section 14, the output terminal insertion connection section 18, and the arcing protection resistor insertion connection section 19 are provided on one printed wiring board 4. Due to the presence of the portion with the maximum potential difference, an extremely large insulation distance is required, resulting in an increase in the size of the mold block 200.

SUMMARY OF THE INVENTION The present invention solves the above problems and aims to provide a high-voltage power supply device for a copying machine that allows a mold block to be miniaturized.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention removes the output terminal insertion connection part and the arcing protection resistance insertion connection part from the printed wiring board, and inserts and fixes the output terminal into the insulating cover. One end of the arcing protection resistor is electrically connected and that part is covered with an insulating resin. In addition, in the case of the output lead wire method, a relay terminal is used instead of the output terminal, and the output lead wire is electrically connected to one of the relay terminals.In this case, a hole is provided around the relay terminal fitting part of the insulating cover, Insulating resin is filled into the insulating cover through this hole to cover the base of the output lead wire.

Effects The present invention can reduce the potential difference by removing the portion of the printed wiring board with the maximum potential difference, and reduce the number of parts on the printed wiring board, as well as reduce the number of parts between the output terminal (or relay terminal) and the arcing protection resistor. As a result of covering the periphery of the connecting portion with insulating resin, the insulation distance from the periphery can be considered as through-insulation of the insulating resin, and the distance can be reduced. Further, by using a relay terminal, effects such as the ability to share the mold block manufacturing process and the insulating cover for the output terminal type and lead wire type can be achieved.

Example Embodiments of the present invention will be described below with reference to the drawings.

Components that are basically the same as those in the conventional example described above are given the same numbers and explanations are omitted, and only the portions of the mold block 2o that are the features of the present invention will be explained here. The high-voltage power supply device for a copying machine is the same as the conventional example described above, except that the mold block 2° shown in the present invention is used, and therefore a detailed description thereof will be omitted.

FIGS. 1a to 1c show an embodiment of the present invention using an output terminal type. The output terminal 9 is fitted into the insulating cover 29 without a gap, and one end of the arcing protection resistor 8 is electrically connected to one end of the output terminal 9 by soldering or the like. Since there is no gap in the output terminal fitting portion of the insulating cover 29, the insulating resin 12 does not flow into the insulating cover 29.

FIGS. 2A to 2C show an embodiment of the present invention using an output lead wire system. The relay terminal 30 uses an insulating cover 29 that is exactly the same as the above-mentioned insulating cover 29, provided that the shape is smaller than the above-mentioned output terminal at the fitting part of the insulating cover 29.
By creating a gap around the fitting portion, the insulating resin 12 injected by injection molding or the like can be filled into the insulating cover 29 through this gap. 16 is an output lead wire.

FIG. 3 shows a patterned surface of a printed wiring board 4 according to an embodiment of the present invention, and FIG. 4 shows electrical components on the back surface thereof.

In this way, the connection part of the output terminal 9 and the arcing protection resistance insertion connection part are not provided in the printed wiring board 4 of the mold block 20, so the high voltage winding lead-out terminal insertion connection part 1 is not provided.
4' and 17', the number of slits 28 for insulation formed in the printed wiring board 4 is small, and even if the printed wiring board 4 is molded by injection molding of the insulating resin 12, the printed wiring board 4 will not close due to the injection pressure. There will be no deformation.

Effects of the Invention Since the high-voltage power supply device for a copying machine of the present invention is configured as described above, it is possible to significantly reduce the insulation distance within the mold block, thereby achieving miniaturization of the mold block and cost reduction. At the same time, it promotes the commonality of the output terminal system, output lead wire structure, parts, processes, etc., and is extremely useful in practice.

[Brief explanation of drawings]

1 to 4 are drawings showing an embodiment of the present invention,
1A to 1C are a front sectional view, a top view, and a side view showing a mold block of an output terminal type high voltage power supply device for a copying machine;
Figures 2a-C are front cross-sectional views, top views, and side views showing the molded block of the same output lead wire type, Figure 3 is a pattern diagram of the printed wiring board, and Figures 4a and b are parts of the printed wiring board. This is a mounting diagram. 6 to 10 are drawings showing a conventional high-voltage power supply device for a copying machine, and FIG. Figure 6a,
7a to 7C are front views, top views, and side views of the molded block of the output lead wire system, 8a and 8b are sectional views thereof, and 9a and 9b are printed wiring boards. 10a and 10b are component mounting diagrams of the printed wiring board, FIGS. 11 to 16 are diagrams showing general high-voltage transformers for copying machines, and FIG. 11 cl-C is a front view of the external appearance. , a plan view, a side view, and FIGS. 12 to 16 are circuit diagrams of examples of various systems. 1... Ferrite core, 2... Low voltage winding, 3... High voltage winding, 4... Printed wiring board, 6... Capacitor, 6... Discharge resistance, 7... Diode, 8... Arcing protection resistor, 9... Output terminal, 1o...
... Insulation cover, 12 ... Insulation resin, 13.
...High voltage transformer, 15...Output lead wire, 16...Insulation cover, 2o...Mold block, 29...Insulation cover, 3o・
...Relay terminal. Name of agent: Patent attorney Toshio Nakao and one other person θ,
, Ah etc. 2゛ Ine 劃 1 sai et al. 19 73 , , , 嵩ノE trance q out/7 地子 b c'z. Fig. 2 " Mukuha Fig. 3 Fig. 4 α Fig. 5 α Fig. 6 Fig. 7 CH? 0 Fig. 8 α Kan 10F2N Fig. 9/7'II' Gamong 1 1 Meal 1 #%11 Fig. cL Fig. 12 Fig. 13 Fig. 14 Fig. 15

Claims (2)

[Claims] (1) Resistors, capacitors, and diodes are electrically connected on a printed wiring board, and this printed wiring board is electrically connected to a high voltage transformer consisting of a ferrite core, low voltage winding, and high voltage winding, which is different from the above. One end of the resistor is electrically connected to the printed wiring board, the other end is electrically connected to an output terminal, and this output terminal is fitted into an insulating cover that is open on one side, and a part of this insulating cover and a high voltage A high-voltage power supply device for a copying machine, which is made by integrally molding a transformer and a printed circuit board with insulating resin to form a mold block, and electrically connecting the mold block to an electronic circuit. (2) A relay terminal is used as the output terminal, one end of the resistor is electrically connected to the relay terminal, and an output lead wire is electrically connected to the other end, and the area around the relay terminal fitting part of the insulating cover is Claim 1, characterized in that a hole is provided in the insulating cover, and the insulating resin is filled in the insulating cover through the hole.
A high-voltage power supply device for a copying machine as described in .