JPH0459544A - Sheet feeding device for picture forming device - Google Patents

Abstract

PURPOSE:To always keep the number of sheets taken out by means of an adsorber or a separating adsorber at one at a time by providing a separating adsorber to separate sheets from each other when it is detected by a double feed preventing sensor that two sheets are overlapped with each other. CONSTITUTION:An adsorber 22 positioned in the vicinity of a sheet feed cassette 17 is moved toward the sheet feed cassette 17 and brought into firm adhesion to a sheet 16 to adsorb the sheet. After the sheet 16 is sucked and held by means of the adsorber 22, the adsorber 22 is moved to lift the sheet 16. In this case, a separating adsorber 27 positioned to the side end of the sheet feed cassette 17 is moved toward the adsorber 22. Simultaneously, a light receiving part is irradiated with beams from the light emitting part of double feed preventing sensors 28a and 18b, and it is detected whether the two sheets are overlapped with each other in relation to the held sheet. As a result, when the two sheets 16 are overlapped with each other, the separating adsorber 27 sucks and separates the one sheet 16a, held by the adsorber 22, from the other sheet 16b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding device for taking out a document in order to form an image of a document on a paper in an image forming apparatus.

[Conventional technology]

Conventionally, light is irradiated from a light source onto a document placed on a platen glass, a photosensitive recording medium is exposed to the reflected light, and the photosensitive recording medium and paper are combined and subjected to pressure development by a pressure developing device. An image forming apparatus that forms an image of the original is known. The paper is stored in a paper feed cassette, and a suction cup is used to prevent the surface of the paper from being damaged when the paper is taken out to be transported to the pressure developing device. .

[Problem to be solved by the invention]

However, in the paper feed device of such a conventional image forming apparatus, in order to take out the paper from the paper feed cassette, one sheet of paper is sucked by a suction cup, and this second sheet of paper is conveyed to the pressure developing device. However, when the paper is taken out by suction with a suction cup, two sheets of paper may overlap and be taken out at the same time. As a result, if the two sheets of paper are conveyed to a pressure developing device or the like in this state, there is a risk that the image forming device will be left unattended.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding device that conveys one sheet at a time to a pressure developing device or the like of an image forming apparatus even when two sheets of paper are taken out by a suction cup.

[Means for solving the problem] In order to achieve such an object, the present invention includes a paper feed cassette in which paper is stored, and a paper feed cassette for forming an image of a document on the paper. A paper feeding device for an image forming apparatus includes a suction cup for taking out sheets of paper, a double prevention sensor detects whether two sheets of paper are overlapped by the suction cup, and a double prevention sensor detects whether two sheets of paper are overlapped by the suction cup. A separating suction cup is provided to separate the sheets when overlapping is detected.

[Effect]

A suction cup located near the paper feed cassette moves toward the paper feed cassette, comes into close contact with the paper, and sucks it. When the paper is sucked and held by a suction cup, the suction cup moves and lifts the paper. When the paper is lifted by the suction cup, the separation suction cup located at the side edge of the paper feed cassette at this time moves toward the suction cup. Light is emitted from the light emitting part of the double prevention sensor toward the light receiving part to detect whether two sheets of paper are being held one on top of the other.

When two sheets of paper overlap, the separation suction cup suctions and separates one of the sheets held by the suction cup from the other sheet and holds it.

〔Example〕

Hereinafter, the present invention will be explained based on the drawings. 1 to 7 are diagrams showing an embodiment of a paper feeding device in an image forming apparatus according to the present invention.

The photosensitive pressure-sensitive copying machine 1 as an image forming apparatus of this embodiment uses photosensitive paper consisting of photosensitive pressure-sensitive paper (microcapsule paper) and color developer paper. A movable original platen glass 2 and a movable original platen cover 3 are provided on the top plate portion of the copying machine 1, and a desired original 4 is set face down on the original platen glass 2.

A light source using a halogen lamp 5 or the like is installed in the upper part of the copying machine 1, and it irradiates light in a line through a slit hole provided on the top surface of the machine toward the document table glass 2. The emitted light is transmitted through the transparent platen glass 2.
and is reflected by the document 4 placed on top of it. Therefore, exposure scanning of the original 4 is performed by moving the original platen glass 2. The light reflected from the original 4 passes through a filter 6 for adjusting the color tone of the copied image and enters a projection lens 7, and the direction of the light projected by this lens 7 is changed by a pair of reflection mirrors 8.9. An image is formed on a microcapsule paper 11 located along an exposure table 10. The reflecting mirrors 8 and 9 are mounted on a mirror mounting plate, and the optical path length and focus are adjusted by finely adjusting the mounting position of the mirror mounting plate.

On the other hand, a long microcapsule paper 11 is wound around a cartridge shaft 12 and housed in a removable cartridge, and one end of the paper is wrapped around a cartridge shaft 12.
4a, 14b, 14e, pressure developing device 13, and separation mechanism 1
4d and reaches the winding shaft 15. That is, the microcassette paper 11 that comes out from the lower part of the cartridge is guided by the feed roller 14a1 and the guide roller 14b to the exposure table 1.
After passing under 0, the microcapsule paper 11 is supplied to the pressure developing device 13, and the microcapsule paper 11 that has passed through the pressure developing device 13 is guided to the feed roller 14c1 separation mechanism 14d and meandering adjustment roller 14e, and then wound up. It is wound up on the shaft 15. Note that the unexposed microcapsule paper 11 after leaving the cartridge is maintained in an unexposed state by the light shielding cover. Furthermore, the conveyance speed of the microcapsule paper 11 is controlled to be constant and is made to match the moving speed of the document platen glass 2, so that the microcapsule paper 11 has a predetermined amount of the document when passing through the exposure table 10. Lines of latent images are sequentially formed.

A paper feeding device is disposed below the pressure developing device 13, and this paper feeding device will be explained with reference to FIG. In the same figure, a paper feed cassette 17 houses color developer paper (paper) 16, and above the paper feed cassette 17 there is a suction cup 22 for sucking the color developer paper 16 and taking it out from the paper feed cassette 17. It is arranged. The suction cup 22 consists of a suction cup main body 22a made of an elastic body having a substantially conical cylindrical shape, and a base 22b on which the suction cup main body 22a is provided. Developing paper】
Moved towards 6. The suction cup body 22a is the developer paper 1
6, negative pressure is supplied from a negative pressure source (not shown) into this suction cup main body 22a, and only one sheet of developer paper 16 is sucked and separated from the other developer papers 16.

Above and to the side of the paper feed cassette 17 (upper right in FIG. 2) are a first conveyance path entrance section 23 and a second conveyance path entrance section for conveying and guiding the color developing paper 16 to the pressure developing device. 24 are arranged in two stages.

First conveyance rollers 25a, 25b and second conveyance rollers 26a, 26b are provided at the first conveyance path entrance section 23 and the second conveyance path entrance section 24, respectively. The first conveyance path entrance section 23 and the second conveyance path entrance section 24 merge, and the second conveyance path entrance section 24 is a little away from the paper feed cassette 17 side end with respect to the first conveyance path entrance section 23. It is in the same position. A separation suction cup 27 is disposed facing upward between the second conveyance path entrance portion 24 and the side end of the paper feed cassette 17, and this separation suction cup 27 similarly consists of a suction cup body 27a and a base portion 27b.

The base 22b of the suction cup 22 and the base 27b of the separation suction cup 27 are provided with light emitting parts (for example, light emitting diodes) that can face each other.
A translucent double prevention sensor is provided which includes a light receiving section 25a and a light receiving section (for example, a photodiode) 28b. When the developer paper 16 is sucked by the suction cup 22, the suction cup 22
is lifted upward while being held by the The separation suction cup 27 is located below the suction cup 22 that has moved upward, and at this time, the light from the light emitting part 28a of the double prevention sensor is transmitted to the light receiving part 2.
8b, this light passes through the color developing paper 16 and is received by the light receiving section 28b. If two sheets of color developer paper 6 held by the suction cup 22 overlap, the amount of light received by the light receiving section 28b decreases, so that the state in which two sheets of color developer paper 16 overlap is detected.

When the developer paper 16 is taken out one by one by the paper feeder 18, it is conveyed by the feed roller 19a1 and the pinch roller 19b, and after the leading end is aligned by the developer paper roller 19C919d and the registration gate 19e, it is carried into the pressure developing device 13. be done. In this way, the microcalopsel paper 11 and the color developer paper 16 are supplied to the pressure developing device 13 in a state in which they are in close contact with each other and are integrated, and the surface of the microcalopsel paper 11 on which the latent image is formed and the color developer paper 16 are separated. The color developer coated surface is sandwiched between the small diameter roller 13a and the backup roller 13b while being in contact with each other on the inside, and pressure is applied thereto. This pressure destroys the unexposed microcapsules and forms an image on the color developing paper 16.

The microcapsule paper 11 and the color developer paper 16 that have come out of the pressure developing device 13 are separated by a separation mechanism 14d, and then the color development of the color developer paper 16 is promoted by the heat roller 20a of the heat fixing device 20 to form an image. After that, the paper is delivered to a paper ejection tray 21 by a paper ejection roller. Note that the separated microcapsule paper 11 is wound onto the winding shaft 15 via the meandering adjustment roller 14e.

Next, the operation of the paper feeding device 18 will be explained. Paper cassette 1
The suction cup 22 located above the paper 7 moves downward as shown in FIG. 3, comes into close contact with the color developing paper 16, and sucks it.

When the developer paper 16 is sucked and held by the suction cup 22, the suction cup 22 moves upward and is lifted as shown in FIG. When the developing paper 16 is lifted by the suction cup 22, the separation suction cup 27 located at the side end of the paper feed cassette 17 moves below the suction cup 22, as shown in FIG. Light emitting part 28 of double prevention sensor
Light is irradiated from a to the light receiving section 28b, and it is detected whether or not two sheets of developing paper 16 are overlapped. When two sheets of color developer paper 16 are stacked, the separation suction cup 27 sucks and separates the lower color developer paper 16b held by the suction cup 22 from the upper color developer paper 16a, as shown in FIG. .

As shown in FIG.
Then, the lower color developing paper 16b held by the separation suction cup 27 is carried to the second conveyance path 24 by this separation suction cup 27.

At the first conveyance path entrance section 23, the upper color developing paper 16a is conveyed to the pressure developing device 13 by first conveyance rollers 25a and 25b. Further, at the second conveyance path entrance section 24, the lower color developing paper 16b is conveyed to the pressure developing device 13 by second conveyance rollers 26a and 26b. In this way, the color developing paper 16a is produced.

When the conveyance of the suction cup 16b is completed, the suction cup 22 and the separation suction cup 27 move to the initial position shown in FIG. Note that when the double prevention sensor detects that the developer paper 16 held by the suction cup 22 is a single sheet, the separation suction cup 27 moving toward the suction cup 22 does not suck this developer paper 16 and returns to the above-mentioned initial state. Move to the location immediately.

〔Effect of the invention〕

As explained above, according to the present invention, there is a double prevention sensor that detects whether two sheets of paper are overlapped by a suction cup, and a double prevention sensor that detects whether two sheets of paper are overlapped by a suction cup. Since a separation suction cup is provided to separate the paper, only one sheet of paper is always taken out by the suction cup or the separation suction cup, and even if the paper is conveyed as it is to a pressure developing device or the like, the image forming device will not be able to do so. There is no such risk.

[Brief explanation of drawings]

1 to 7 are diagrams showing one embodiment of a paper feeding device in an image forming apparatus according to the present invention, FIG. 12 is a schematic sectional view of the image forming apparatus, and FIG. 2 is a schematic diagram of the paper feeding device. The sectional views and FIGS. 3 to 7 are views showing the operation of the paper feeding device, respectively. 16... Paper, 17... Paper feed cassette, 22... Suction cup, 27... Separation sucker, 28a, 28b... Double prevention sensor. Figure 3 Figure 1 Figure 4

Claims (1)

[Claims] In a paper feeding device of an image forming apparatus including a paper feeding cassette storing paper and a suction cup for taking out the paper from the paper feeding cassette in order to form an image of a document on the paper, the paper is taken out by the suction cup. The device is equipped with a double prevention sensor that detects whether two sheets of paper overlap, and a separation suction cup that separates the sheets when the double prevention sensor detects that two sheets of paper overlap. A paper feeding device in an image forming apparatus, characterized in that: