JPS6119034B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corona generating device for a copying machine which is driven by a direct current including ripples.

In electronic copying machines, a corona generating device is used for charging, transferring, and eliminating static electricity. This corona generating device includes a high pressure generating section, which uses a ferro-resonant circuit,
Some use piezoelectric transformers and others use high-frequency inverters.
The latter two tend to be frequently used due to the demand for weight reduction. In addition, devices using inverter circuits are considered important because they allow easy variable output and can be further miniaturized by increasing the oscillation frequency. However, there is a limit to the miniaturization of the transformer and other electrical components, and therefore the power supply section has not been miniaturized to the desired extent.

Here, the present invention focuses on the fact that the corona generating part essentially has a capacitance within a certain range, and also that the smoothing capacitance can be relatively small when high frequencies are rectified. This was done based on the fact that a sufficiently good copying effect can be obtained even if the corona generating device is driven by a direct current containing ripples below a certain amount, and it is sufficiently small without deteriorating the copying effect. An object of the present invention is to provide a corona generating device for a copying machine that can be used as a copier.

The present invention rectifies the output of a high-frequency power source using a rectifier that does not use a special capacitor for smoothing, applies it to a corona generating section, and smoothes the output to the rectifying device using the capacitance of the corona generating section. The ripple content of the above corona generating area
It is characterized by being driven by direct current containing ripple of 60% or less.

According to the present invention, since a special smoothing capacitor is not connected and used as a rectifier, the number of parts is reduced, and the device can be made smaller and lighter. In addition, a corona generating device for a copying machine can be provided at low cost. In addition, the copying effect, that is, the quality of the copied image, does not deteriorate in any of charging, transfer, and neutralization compared to those not based on the present invention. According to experiments, it was also confirmed that the copying effect was rather improved. In the present invention, the reason why the DC ripple content is limited to 60% or less is because, as a result of experiments, if this value is exceeded, the copying effect deteriorates significantly and is no longer practical, whereas the above range is sufficient for practical use. This is because it will be done. Therefore, the effects of the present invention cannot be obtained simply by not using a smoothing capacitor connected to the rectifier; in addition, the direct current that drives the corona generating section contains ripples, and the ripple content rate is is 60%
There must be a configuration in which: In addition, as a high frequency power supply, its oscillation frequency is
A frequency of 15 to 50 KHz is advantageous for downsizing parts such as transformers, and also facilitates setting the DC ripple content to 60% or less in interaction with the capacitance of the corona generating section. In addition, a corona generation part with a capacitance of 15 to 100 pF can be easily obtained, and with this level of capacitance, the ripple content can be kept within a predetermined range in interaction with the oscillation frequency. Easy to set up. The capacitance possessed by the corona generating section is mainly line capacitance and stray capacitance. In addition to the capacitance caused by the corona generation part, it is also possible that the capacitance is caused by line capacitance, stray capacitance, etc. in other parts, but this is negligible compared to the former.

The invention will now be described with reference to illustrated embodiments. In the figure, 1 is a high frequency power supply, 2 is a rectifier, and 3 is a corona generating section. The high-frequency power source 1 includes an inverter 4 and a DC power source 5, and its oscillation frequency is appropriately set within the above-mentioned range. In addition,
As the DC power source 5, a rectified commercial power source is used, but a battery power source or the like may also be used. 6 is an output transformer of the inverter 4. The rectifier 2 is not connected to a smoothing capacitor and is connected to the output end of the high frequency power supply 1, that is, the secondary winding of the output transformer. Although half-wave rectification is used in this embodiment, full-wave rectification may also be used. The corona generating section 3 is connected to the output end of the rectifier 2. The capacitance of the corona generating section 3 is appropriately selected within the above-mentioned range. The corona generating section 3 is then driven by a direct current containing ripples with a ripple content of 60% or less. This can be easily configured by appropriately selecting the oscillation frequency of the high frequency power source 1 and the capacity of the corona generating section 3.

Next, the circuit operation will be explained. DC power supply 5
When the inverter 4 is turned on, the inverter 4 operates, and a high voltage and high frequency is obtained between the secondary windings of the output transformer 6. This high frequency is rectified by the rectifier 2 and further applied to the corona generating section, but a smoothing effect is performed by the capacitance of the corona generating section 3, and the corona generating section 3 is driven by DC including ripples. becomes. Since the ripple content is 60% or less, the copying effect is sufficient for practical use as described above.

As detailed above, the present invention connects a rectifier that does not use a smoothing capacitor between the high frequency power source and the corona generating section, and also performs a smoothing effect using the capacitance of the corona generating section. Since the corona generation part is configured to be driven by ripple-containing DC with a ripple content of 60% or less, no special capacitor is connected as a smoothing capacitor, so the number of parts is reduced, making it compact and lightweight. It is possible to provide a corona generating device for a copying machine that is inexpensive and has sufficient practicality in terms of copying effects.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing an embodiment of the present invention. 1... High frequency power supply, 2... Rectifier, 3... Corona generating section.

Claims (1)

[Scope of Claims] 1. A high-frequency power source; A rectifier connected to the output end of this power source and not using a smoothing capacitor; A corona generating section connected to the output end of this rectifier; A corona generator for a copying machine, characterized in that a smoothing effect is imparted to the rectifier by the electrostatic capacitance of the corona generator, so that the corona generator is driven by direct current containing ripples with a ripple content of 60% or less. Device. 2. The corona generating device for a copying machine according to claim 1, wherein the corona generating section has a capacitance of 15 to 100 pF. 3. The corona generating device for a copying machine according to claim 1 or 2, wherein the high frequency power source generates a high frequency output of 15 to 50 KHz.