JPS6256057B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sheet feeding device used for feeding sheets of paper etc. in a copying machine, a printing machine, etc., and particularly relates to a sheet feeding device that uses a roller system. This invention relates to improvements in feeding devices.

[Prior art]

An example of a conventional sheet feeding device is a paper feeding device that feeds paper sheet by sheet from a stack of sheets stacked in a copying machine, printing machine, etc.
2. Description of the Related Art A widely used device is a method in which a rubber roller for paper feeding is brought into pressure contact with a stack of paper, and the rubber roller is rotated to feed the paper by friction with the paper. In addition, as a paper feeding device, there is also known a method of feeding paper by air suction called a sniffer in high-speed machines and the like.

(Problem to be solved by the invention) However, in the former case, the hardness of the rubber roller changes depending on temperature, time, toner, ozone, etc., and the coefficient of friction with the paper changes. When the rubber roller deteriorates and the coefficient of friction decreases, paper feeding failures occur, such as paper feeding not being performed. On the other hand, in the latter case, there are problems such as the device becomes large-scale and noise is likely to be generated.

As a means to solve this problem, a predetermined electrode pattern is provided on the circumferential surface of the roller, and a voltage is applied to this electrode pattern to generate electrostatic adsorption force, and this electrostatic adsorption force is used to hold sheets such as paper. There is a model that allows suction and delivery (for example, Japanese Patent Application Laid-open No. 114424/1983), but in this type,
Since the power source that is the means for applying voltage to the electrode pattern is provided outside the roller, the external power source and the electrode pattern must be connected using a contact brush or the like so as not to interfere with the rotational operation of the roller. Not only does this complicate the structure for supplying electricity to the electrode pattern, but also there is a risk that poor sheet feeding or high voltage shoots may occur due to poor contact with the contact brush.

[Means for Solving the Problems] The present invention has been made by focusing on the above problems, and improves the durability of the device while effectively avoiding the problems of increasing the size of the device itself and generating noise. To provide a sheet feeding device which is capable of improving performance, has a simple and safe configuration, and can reliably supply sheets at all times.

That is, the present invention provides a hollow roller having a dielectric layer provided on its surface and at least one pair of electrodes provided inside the hollow roller, and the above-described material loaded inside the roller to generate an electrostatic adsorption force on the roller. The sheet feeding device is equipped with a power source that applies voltage to the electrodes.

In such technical means, the electrodes may be a set of comb-shaped electrodes, or multiple sets of individual electrodes may be arranged and each set is energized. There is no harm in doing so. Further, the area where the electrodes are provided is not limited to the entire area of the roller, and may be provided partially.

Further, the power source is not limited to a combination of a battery and a voltage booster, and may be selected as appropriate as long as it can apply a voltage sufficient to generate a predetermined electrostatic adsorption force on the roller.

[Function] According to the above-mentioned technical means, when a voltage is applied to the electrode portion of the roller by the power supply device inside the roller, a strong electric field is generated in this electrode portion, and static electricity based on this strong electric field is generated. The sheet is attracted and delivered by the electrostatic attraction force and the rotation of the roller.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 and 2 show the external appearance and internal structure of an embodiment of the present invention, and FIG. 3 shows its circuit configuration.

In FIGS. 1 and 2, 1 is an electrostatic adsorption roller for paper feeding, 2 and 3 are a battery chamber and a booster chamber for storing the battery and a booster, and 4 is a one-way clutch provided at one end. A joint portion 6 is formed on the rotating shaft 5 on the one-way clutch 4 side to receive rotational force from a drive shaft (not shown). As shown in FIG. 2, the electrostatic adsorption roller 1 is rotatably attached to a frame 8 by having a one-way clutch 4 and a rotating shaft 5 on the lid 7 side supported by the frame 8 through bearings 9, respectively.

The electrostatic attraction roller 1 is provided with a pair of comb-shaped electrodes 11a and 11b on the surface of a cylinder 10 made of resin, as shown in FIGS. It is constructed by covering it with a dielectric layer 12 consisting of. The pair of electrodes 11a, 11b is formed between the dielectric layer 12 and the cylinder 10 by heat welding the above-mentioned resin cylinder 10 with the dielectric layer 12 interposed between the electrodes 11a, 11b. Fixed. The inside of the electrostatic attraction roller 1 is hollow, and the electrode 11
A power source for obtaining power to be supplied to the electrostatic attraction rollers 1 and 11b is built into the electrostatic attraction roller 1.
That is, two batteries 13 of, for example, 1.5V and a booster 14 are built into the hollow resin cylinder 10, and the batteries 13 are electrically connected to the booster 14. The booster 14 is a DC-DC converter, and boosts the voltage of the battery 13 by, for example, 1000 times to 3000V so that an electrostatic field is formed by the electrodes 11a and 11b.
Power is supplied to the terminals a and 11b. When a high DC voltage is applied between the electrodes 11a and 11b in this way, a strong electric field is generated between the electrodes 11a and 11b, which is electrostatically induced in the paper placed nearby.
The paper to be sent out is attracted to the electrostatic attraction roller 1,
It is designed to be sent out as the electrostatic attraction roller 1 rotates.

According to the above configuration, when feeding out sheets of paper one by one from a stacked stack of papers, simply by lightly pressing the electrostatic attraction roller 1 onto the stacked papers, the paper will be attracted to the electrostatic attraction roller 1 and the paper will be attracted to the electrostatic attraction roller 1. For example, when a copying process begins in a copying machine, the previously mentioned drive shaft (not shown) rotates in response to a paper feed signal, and this rotational force is received by the joint section 6, which is then transferred via the one-way clutch 4 to the electrostatic adsorption roller 1. When it receives rotational force from the joint part 6 and rotates, the paper that has been attracted can be sent out. For this reason, stable paper feeding can be performed without causing paper feeding failures such as paper feeding not being performed due to changes in the coefficient of friction as in the case of conventional rubber rollers, and reliable paper feeding can be maintained. be able to. Furthermore, the device does not become large-scale and no noise problem occurs. Furthermore, since the suction force acts only slightly on the second sheet of stacked paper, the paper can be fed out one sheet at a time. Note that in order to more reliably prevent double feeding, a paper presser claw may be provided. Furthermore, although a device for applying a voltage to the electrodes 11a and 11b is provided to supply power, since the power consumption is small, there is no need to provide a switch to cut off the power supply, and the structure may be such that the power is constantly supplied. .

The electrostatic adsorption roller 1 as a paper feeding roller is
Since the dielectric layer 12 is provided on the surface and the pair of comb-shaped electrodes 11a and 11b are provided inside the dielectric layer 12, the inside can be made hollow, and a power supply device can be built into the inside. If the structure is built in using the inside, there is no need to receive power from an external source, so contact brushes are no longer necessary, and problems such as paper feeding failures and high voltage shoots due to poor contact with the contact brushes can be prevented. can.

In addition, in the above embodiment, the electrostatic adsorption roller 1 is
Although the case of books has been explained, a plurality of books may be arranged coaxially, and in this case, claws for paper separation may be provided between the rollers. Further, in the above description, the case where the stacked sheets are sent out from the top surface is taken as an example, but the present invention is not limited to this. For example, it is of course applicable to the case where the paper is sent out from the bottom surface.

〔Effect of the invention〕

As explained above, according to the sheet feeding device according to the present invention, the sheet feeding device according to the present invention is not affected by changes in the coefficient of friction unlike the case of rubber rollers, and stably feeds the sheet by using uniform electrostatic adsorption force. Therefore, sheets can be fed reliably over a long period of time, and there is no risk of the device becoming bulky or generating noise, unlike in the case of air suction.

Furthermore, according to this invention, the roller has a built-in power supply for applying voltage to the electrodes for generating electrostatic adsorption force, so the structure for supplying electricity to the electrodes is simpler and safer than a type that uses an external power supply. can be made into something.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a sectional view showing its internal structure, and FIG. 3 is a circuit diagram showing the circuit configuration. Code explanation, 1... Electrostatic adsorption roller (roller),
11a, 11b...comb-shaped electrodes (electrodes), 13...
...battery (power supply), 14...booster (power supply).

Claims (1)

[Scope of Claims] 1. A hollow roller 1 provided with a dielectric layer 12 on its surface and provided with at least a pair of electrodes 11a and 11b inside the hollow roller 1;
The electrode 11 is used to generate electrostatic adsorption force on the
A sheet feeding device comprising power supplies 13 and 14 that apply voltage to terminals a and 11b, and in which the electrostatic attraction force is generated and the rotating roller 1 attracts and feeds the sheet.