JPH097U - Image forming device - Google Patents

Abstract

(57) An object of the present invention is to provide an image forming apparatus having a paper feed mechanism that aligns the edges of paper with a simple mechanism. SOLUTION: A paper feeding roller 4 that is provided so as to be able to come into contact with and separate from a paper 2 stacked on a paper tray 1 and that feeds the paper from the paper tray 1 when in contact with the paper 2, and a paper feeding roller 4. A shaft 5 that is interlocked with the contact and separation operation of the shaft 5, a stopper 6 that is configured separately from the shaft 5, and a positioning that is rotatably provided on the shaft 5 and that positions the paper edge of the paper on one side of the shaft 5. A sheet leading edge positioning member having a portion 3a and an engaging portion 3b that engages and disengages with the stopper 6 on the other side, and is provided with a center of gravity at a position where the rotational force in the direction opposite to the sheet feeding direction in the positioning portion 3a is generated by its own weight. 3 and 3.

Description

[Detailed description of the device]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an image forming apparatus such as a copying machine or a printing machine having a mechanism for feeding sheets one by one in an orderly manner from a sheet tray.

[0002]

[Prior art]

 Paper used in a copying machine or a printing machine is roughly classified into a roll shape and a sheet shape. Of these, sheet-shaped sheets are accommodated in a sheet tray and fed one by one. At this time, if the leading end portions of the papers are not aligned, a double feed in which a plurality of papers are sent out at the same time, a skew in which the papers are sent in an inclined state with respect to the carrying direction, and the like occur.

Therefore, conventionally, in order to align the edges of the paper, as shown in FIG. 3, a method has been employed in which a paper leading edge positioning member is brought into contact with the edges of the paper by an independent mechanism, as shown in FIG. . That is, the paper leading edge positioning member 33, which comes into contact with the delivery side end of the paper 32 stored in the paper tray 31, is arranged so as to be movable up and down by a link mechanism incorporating a solenoid 34. The sheet 32 in the sheet tray 31 is set at a predetermined position by the sheet leading edge positioning member 33 contacting the edge of the sheet 32.

When the paper 32 is sent out from the paper tray 31, the solenoid 34 depresses the paper leading edge positioning member 33 and the paper feeding roller 35 to bring it into contact with the upper surface of the paper 32. The paper 32 is sent out from the paper tray 31 to the paper feed roller 36 by the rotation of the paper feed roller 35. The friction pad 37 is pressed against the paper feed roller 36, and the fact that the frictional force between the paper 32 and the friction pad 37 is larger than the frictional force between the papers 32 allows the papers 32 to be conveyed one by one. ing.

[0005]

[Problems to be solved by the device]

 However, incorporating the sheet leading edge positioning member 33 driven by an independent mechanism into a copying machine or a printing machine as described above complicates the structure of the apparatus. In addition, the effective space inside the device is reduced, and maintenance and inspection work becomes troublesome. Looking at the drive mechanism itself of the sheet leading edge positioning member 33, the solenoid 34 and the link mechanism are required, which not only causes a cost increase but also the vertical movement of the sheet leading edge positioning member 33 by the solenoid 34 causes the sheet feeding roller 35 to move. It will be necessary to synchronize with the lifting. If this synchronization is incomplete, the reliability of the device is reduced, but in order to complete the synchronization, a control system incorporating a corresponding program is required.

In view of this, the present invention mechanically links the timing at which the positioning member abuts against the edge of the paper with the elevating and lowering of the paper feeding roller, thereby driving the paper leading edge positioning member. An object of the present invention is to provide an image forming apparatus having a paper feed mechanism that aligns the edges of paper with a simple mechanism without using the paper.

[0007]

[Means for Solving the Problems]

 In order to achieve the object, the image forming apparatus of the present invention is provided so as to be able to come into contact with and separate from a sheet tray on which sheets are stacked and sheets stacked on the sheet tray, and is stacked on the sheet tray. A paper feed means for feeding the paper from the paper tray when it is in contact with the paper, a rotary shaft that interlocks with the contact / separation operation of the paper feed means, and a stopper formed separately from the rotary shaft. And a positioning portion that is rotatably provided on the rotary shaft and that positions the paper edge of the paper on one side with respect to the rotary shaft, and engages and disengages with the stopper on the other side with respect to the rotary shaft. A sheet leading edge positioning member having an engaging portion and having a center of gravity set so that a rotational force in a direction opposite to the sheet feeding direction at the positioning portion is generated by its own weight.

[0008]

【Example】

 Hereinafter, the features of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a state in which the sheet leading edge positioning member is in contact with the edge of the sheet in the image forming apparatus according to the embodiment of the present invention. The positioning portion 3a of the paper leading edge positioning member 3 abuts on the delivery-side end surface of the paper 2 placed on the paper tray 1. The sheet leading edge position determining member 3 is swingably attached to a shaft 5 of a feeding roller 4 which is arranged above the sheet tray 1 so as to be vertically movable. An engaging portion 3b that engages with a stopper 6 provided above the feeding roller 4 is formed at the upper end of the sheet leading edge positioning member 3.

The center of gravity of the sheet leading edge positioning member 3 is set to the left side in FIG. 1 with respect to the mounting portion 3c for the shaft 5. Therefore, in the free state, the paper leading edge positioning member 3 hangs down from the shaft 5 with the positioning portion 3a facing downward, and receives the counterclockwise rotational force. With this force, the end faces of the paper 2 are aligned. Further, the clockwise rotation is restricted by the stopper 6.

In the state of FIG. 1, since the positioning portion 3 a of the paper leading edge positioning member 3 is in contact with the end surface of the paper 2, the paper 2 stored in the paper tray 1 is positioned by this positioning portion 3 a. . When the feeding roller 4 is lowered from this state, the engagement state of the engaging portion 3b with the stopper 6 is released, and the sheet leading edge positioning member 3 becomes swingable.

Further, when the feeding roller 4 is lowered and brought into contact with the upper surface of the uppermost sheet 2, the sheet 2 is delivered from the sheet tray 1 by the rotation of the feeding roller 4. At this time, the sheet leading edge positioning member 3 tilts as shown in FIG. 2 with the movement of the fed sheet 2. Then, the sheet 2 that has passed the lower end side of the positioning section 3a passes between the feed roller 7 and the friction pad 8 and is conveyed one by one to the copying or printing process.

When copying or printing is completed, the operation of the operation board causes the feeding roller 4 to rise from the state of FIG. 2 in contact with the sheet 2 to the state of FIG. At this time, since the center of gravity of the paper leading edge positioning member 3 is on the left side of the shaft 5, the paper leading edge positioning member 3 turns counterclockwise as the feeding roller 4 moves up. Then, when the feeding roller 4 is further raised while the engaging portion 3b is erected, the engaging portion 3b returns to the state of FIG. 1 in which the engaging portion 3b contacts the left side surface of the stopper 6.

Due to the positional relationship between the center of gravity of the paper leading edge positioning member 3 and the shaft 5, a slight counterclockwise rotational force is applied to the paper leading edge positioning member 3. With this force, the end faces of the sheets 2 in the sheet tray 1 are realigned. In order to reliably perform the swinging of the sheet leading edge positioning member 3 and the engagement with the stopper 6 described above, the engaging distance L1 between the engaging portion 3b and the stopper 6 is set so that the engaging portion 3b is in the upright state. It is preferable to make the distance smaller than the minimum moving distance L2 of the feeding roller 4 in consideration of the rising distance while maintaining.

[0014]

[Effect of the invention]

 As described above, in the present invention, the end portions of the sheets accommodated in the sheet tray are aligned by the sheet leading edge positioning member that swings as the feeding roller moves up and down. Therefore, unlike the conventional case, it is not necessary to move the paper leading edge positioning member by a dedicated drive mechanism, which is not only structurally simple, but also the contact of the paper leading edge positioning member with the paper edge and the feeding roller for the paper. It is sure to synchronize with the raising and lowering of. Therefore, it becomes possible to perform operations such as aligning the edges of the paper and feeding the paper with high reliability with a simple equipment configuration. Further, since the turning force works so that the positioning portion of the sheet leading edge positioning member returns to the positioning position by its own weight, it is not necessary to provide a complicated mechanism. Therefore, an image forming apparatus having a simple structure and high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a state in which a sheet leading end positioning member is in contact with an end of a sheet in the image forming apparatus according to the embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a state in which paper is being sent from a paper tray.

FIG. 3 is a schematic sectional view showing an image forming apparatus provided with a conventional sheet leading end positioning member.

[Explanation of symbols]

 1: paper tray 2: paper 3: paper leading end positioning member 3a: positioning part 3b: engaging part 3c: mounting part 4: feed roller 5: shaft 6: stopper 7: feed roller 8: friction pad

Claims (3)

[Utility model registration claims] 1. A sheet tray on which sheets are stacked, and a sheet tray that is provided so as to be capable of coming into contact with and separated from sheets stacked on the sheet tray, and from the sheet tray when in contact with the sheets stacked on the sheet tray. A sheet feeding unit that feeds out a sheet, a rotating shaft that interlocks with a contacting / separating operation of the sheet feeding unit, a stopper that is configured separately from the rotating shaft, and is rotatably provided on the rotating shaft. A sheet having a positioning portion for positioning the sheet end of the sheet on one side of the rotating shaft and an engaging portion for engaging and disengaging the stopper on the other side of the rotating shaft; An image forming apparatus, comprising: a sheet leading edge positioning member whose center of gravity is set so that a rotational force in a direction opposite to a feeding direction is generated by its own weight. 2. The image forming apparatus according to claim 1, wherein the center of gravity of the sheet leading edge positioning member is located downstream of the center of the rotating shaft in the sheet feeding direction. 3. A separating / conveying member, which is provided downstream of the positioning position of the positioning unit in the paper feeding direction, and which conveys the papers fed by the paper feeding unit one by one toward the printing process. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.