JPH0231462Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a paper feeding device used in a copying machine or the like.

[Prior Art] Until now, in Japan, there has been no transfer paper of the same size in the longitudinal direction and different lengths in the transverse direction. Therefore, if the length in the longitudinal direction was known, the length in the transverse direction was necessarily determined, with the condition that the material be conveyed in a direction perpendicular to the longitudinal direction. Therefore, in the paper feed tray where the transfer paper is placed, the side guide is pressed against the transfer paper to detect the length in the longitudinal direction, and the A3, A3,
The size of the transfer paper such as B4 was displayed.

However, in other countries, as shown in FIG. 2, paper having the same length W in the longitudinal direction and different lengths L in the transverse direction is used as transfer paper. In this case, even if the length in the longitudinal direction is determined by the side guides, the length in the transverse direction cannot be determined, and therefore, there is a problem in that the size of the transfer paper cannot be displayed.

In order to overcome these drawbacks, a paper feeding device has been proposed, for example, as described in Japanese Patent Application Laid-Open No. 58-207227.

In this paper feeding device, a plurality of holes are formed at predetermined positions on a table on which paper is placed, and a light emitting element and a light receiving element form a pair and face each other with the respective holes sandwiched therebetween. Then, the position of the hole that is covered by the rear end of the paper placed on the mounting table is detected based on the output state of the light receiving element, and the size of the paper on the mounting table is determined based on the output state of the light receiving element. It has become a system for making decisions.

However, in this paper feeding device, if the paper on the mounting table curls upward, the trailing edge position of the paper is optically detected to be shorter than the actual position, which causes size error detection. In particular, since there are heat sources inside the copying machine, such as a fuser with a built-in heater and a drive motor, the heat from these sources causes the copying machine to become extremely hot and dry, a condition that tends to cause the transfer paper to curl. Therefore, the above-mentioned false detection is likely to occur.

Further, a paper feeding device as described in, for example, Japanese Patent Application Laid-open No. 133137/1983 has been proposed.

This paper feeding device includes a feeding unit that feeds paper stored in a paper feeding cassette that is removably attached to the main body of the device, and a feeding unit that moves in a direction perpendicular to the paper feeding direction of the paper feeding cassette to feed the paper in the feeding direction. a paper guide plate that guides the paper to the feed direction; a first detection means that detects the length of the paper in a direction perpendicular to the paper feed direction; and a second detection means that detects the length of the paper in the paper feed direction. ing. The size of the paper placed on the paper feed cassette is detected based on the detection signals from the first detection means and the second detection means.

In the second detection means, the detection lever rotates only when the end of the detection lever is pressed by the paper being placed, and the magnet fixed to one end of the detection lever moves relative to the reed switch. By operating this, the length of the sheet in the feeding direction is detected.

However, even with this paper feed device, if the number of sheets on the paper feed cassette decreases or the paper is in the cart, the detection lever will not operate even though there is paper, and the wrong size will be detected. It turns out.

[Purpose] The purpose of the present invention is to solve the problems of the prior art described above, and to provide a paper feed system that can accurately detect the size of paper even when the number of sheets of paper is small or even when the paper is curled. It provides equipment.

[Configuration] In order to achieve the above object, the present invention includes a paper feed tray that is movable up and down with paper to be fed loaded thereon, and a leading edge in the paper feeding direction of the paper stacked on the paper feed tray. a reference wall that aligns the paper feed position by abutting the paper feed rollers, and a paper feed roller that is installed near the paper feed position and feeds the topmost paper stacked on the paper feed tray into the paper feed path. , provided near the bottom wall of the paper feed tray and corresponding to the rear end in the paper feed direction of the paper stacked on the paper feed tray, and moves up and down together with the paper feed tray;
A detection means for detecting the length of the paper in the feeding direction, and a detection means provided at a position not directly above the raised position of the detection means, and configured to feed the loaded paper when the paper feed tray is raised to the paper feed position. The present invention is characterized in that it includes a pressing member that presses toward the bottom wall of the tray.

The present invention will be explained in detail below based on one embodiment of the present invention.

FIG. 1 shows a schematic configuration of a copying machine according to an embodiment of the present invention. Transfer paper 2 placed on paper feed tray 1
is transferred to the registration roller 6 via the paper feed roller 3, separation roller 4, and conveyance roller 5 during the transfer operation.
transported to. Then, the toner image on the photosensitive drum 7 is transferred to the transfer paper 2 by the transfer charger 8 and the separation charger 9 in contact with the photosensitive drum 7, and is separated from the photosensitive drum 7 and placed on the conveyor belt 10.
Head to. Then, the transfer paper 2 passes through a fixing roller 11 having a built-in heater to fix the toner image thereon, and then heads toward a paper discharge tray 12.

Around the photoreceptor drum 7, there are separating claws 13,
Drum cleaning section 14, charging charger 1
5, an eraser 16, a developing section 17, etc. are arranged.

The specific configuration of the paper feed tray 1 will be described below. As shown in Figures 3 and 4,
A through hole 1a is formed in the lower wall of the paper feed tray 1, and a lever body 1 is provided below the through hole 1a, which has a key-shaped detection portion 18a at the tip and a blocking portion 18b at the rear.
8 is pivotally supported while being elastically biased clockwise. The blocking portion 18b of the lever body 18 has the function of blocking or passing the light from the photo interrupter 19 as the lever body 18 rotates. Therefore, the lever body 18 and the photo interrupter 19 constitute a paper size detection means 23.

Therefore, in FIG. 2, the transfer paper 2 has the same width (W ₁ = W ₂ ) but different length (L ₁ ≠L ₂ ).
is determined as follows. For example, when a transfer paper 2 with a widthwise length of L ₁ is placed on the paper feed tray 1, the detection part 18a of the lever body 18 enters the through hole 1a of the paper feed tray 1 as shown in FIG. . Then, the photo interrupter 19
8b does not block the light, resulting in an on state.

Furthermore, when the transfer paper 2 having a widthwise length of L ₂ is placed on the paper feed tray 1, the detection part 18a of the lever body 18 is inserted into the through hole 1a of the paper feed tray 1 as shown in FIG. I can't get into it. Then, the light from the photo interrupter 19 is blocked by the blocking portion 18b, and as a result, the photo interrupter 19 is turned off.

Therefore, by combining the length detection in the longitudinal direction by the known side guide and the detection in the transverse direction by turning on and off the photo interrupter 19, W ₁ of the transfer paper 2 shown in FIG.
Can distinguish between ×L ₁ and W ₂ ×L ₂ sizes.

The detection members (lever body 18, photo interrupter 19) are configured to rise together with the paper feed tray 1 as it rises to the paper feed position (the position indicated by the two-dot chain line).

Here, we will explain why it is necessary to detect the length of the transfer paper in the transverse direction. The length of the transfer paper in the longitudinal direction is the same, and the feeding direction (width direction)
Different lengths change the working area. That is, if an image is formed on a long transfer paper, an untransferred image will remain when a short transfer paper is used, and the cleaning load will increase. In the opposite case, a portion without an image occurs at the end of a long transfer paper, resulting in image loss. Therefore, in order to solve these problems, it is necessary to detect the length in the feeding direction.

Furthermore, as shown in FIG. 5, when the above-mentioned detection members (lever body 18, photo interrupter 19) are installed on the paper feed tray 1, the paper feed tray 1 is moved at least to the paper feed position (the position shown by the two-dot chain line). It is necessary to arrange a pressing member 20 for pressing the transfer paper 2 toward the bottom plate of the paper feed tray 1 when the transfer paper 2 is raised. This pressing member 20, as shown in FIG.
It is not placed directly above the lever body 18, but is placed on the paper feed tray 1 very close to it to prevent the pressing member 20 from being detected when there is no transfer paper 2. As shown in FIG.
In order to prevent erroneous detection due to curling or other lifting of the transfer paper 2 due to the lever body 18 not rotating even though the transfer paper 2 is present, the transfer paper 2 is
8. It has a pressing effect near the photo interrupter 19). If the pressing member 20 is away from the sensing member (lever body 18, photo interrupter 19), the force for pressing the transfer paper 2 near the sensing member disappears or becomes extremely small. As a result, the transfer paper 2 may be lifted by the lever body 18 or curled.
Appropriate size detection will not be possible. In addition, in the case of a paper feeding system based on one side, a weight for preventing skew may be installed on the reference side, and it can also be used as a weight in that case.

In FIG. 6, 21 is a reference wall, 22 is a sideoid, and the pressing member 20 is a reference wall 2.
It is supported by 1.

When detecting the size of the transfer paper 2 using the lever body 18 and the photo interrupter 19, the photo interrupter 19 is turned on and off in the opposite way to the above embodiment. 19 may be turned off and turned on when the time is long.

[Effects] As explained above, according to the present invention, even if the number of sheets of paper on the paper feed tray is small or even if the paper is slightly curled, the size can be detected accurately. It is possible to provide a paper feeding device that does not have to worry about erroneous detection due to the presence of a pressing member.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the outline of a copying machine, FIG. 2 is a perspective view showing differences in the size of transfer paper, and FIGS. 3 and 4 are side views illustrating the operation of an embodiment of the present invention. FIG. 5 is a side view showing the relationship with the pressing member of the same embodiment, and FIG. 6 is a plan view showing the arrangement relationship of the same embodiment. 1...Paper feed tray, 1a...Through hole, 2...Transfer paper, 3...Paper feed roller, 18...Lever body, 18
a...detection section, 18b...blocking section, 19...photo interrupter, 20...pressing member, 21...reference wall, 23...detection means.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A paper feed tray 1 loaded with paper 2 to be fed and provided so as to be movable up and down, and the feeding direction of the paper 2 loaded on the paper feed tray 1 A reference wall 21 that aligns the paper feeding position of the paper 2 by abutting the leading ends thereof, and a paper feeding tray 1 that is provided near the paper feeding position.
A paper feed roller 3 that feeds the uppermost paper 2 stacked on top into the paper feed path, and a rear end in the paper feed direction of the paper 2 stacked on the paper feed tray 1 near the bottom wall of the paper feed tray 1. a detection means 23 for detecting the length of the paper 2 in the feeding direction, which is provided in the vicinity corresponding to the paper feed tray 1 and moves up and down together with the paper feed tray 1; A pressing member 20 for pressing stacked papers 2 toward the bottom wall of the paper feeding tray 1 when the paper feeding tray 1 is raised to the paper feeding position. . (2) In the utility model registration claim (1), the detecting means 23 includes a through hole 1a formed in the bottom wall of the paper feed tray 1, and a detection device capable of penetrating the through hole 1a. body 18 and its detection body 1
The detection element 18b and 19 detect whether or not the paper 8 has passed through the through hole 1a. In one case, the body 18 does not pass through the hole 1a, and in the other case, the hole 1a is not blocked by the paper 2 loaded on the paper feed tray 1, and the detection object 18 passes through the hole 1a. A paper feeding device characterized in that it is configured to detect the length of the paper 2 in the feeding direction depending on whether the paper 2 is fed or not.