JPH11272028A - Home position detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of accurately detecting a home position. SOLUTION: A pair of width adjusting guides 4 and 5 mutually interlocked by a rack and a pinion mechanism 6 is provided at both side parts of an intermediate tray 1, and a body to be detected 54 for detecting the home positions of the guides 4 and 5 is provided at a position on a pinion axial line G in either guide 5. Thus, the rocking width of the body 54 is made comparatively small and the detecting accuracy of the home position is remarkably improved, and the occurrence of image deviation and jamming is restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a double-sided copy for forming an image on both sides of a sheet, a multiplex copy for copying a plurality of originals on a single sheet, a multicolor copy for coloring a plurality of colors, and the like. The present invention relates to a device for detecting a home position of a width adjustment guide of an intermediate tray provided in an image forming apparatus for performing the operation.

[0002]

2. Description of the Related Art An intermediate tray provided in a copying machine or the like capable of performing double-sided copying forms an image on one side of a sheet and stores the sheet in a stacked state until the sheet is fed again. By this time, the width of the stacked sheets is adjusted by the width adjustment guides provided on both sides of the intermediate tray.

For example, as shown in FIG. 6, a width adjusting mechanism for an intermediate tray a includes a pair of width adjusting guides c and d interlocked with each other by a rack and a pinion mechanism b, and a driving source (shown in FIG. 6) for driving the pinion e. Omitting), a detected element f protruding from one end of one of the width adjusting guides d, a sensor g for detecting the detected element f, and the like. The intervals c and d are automatically adjusted, but prior to the adjustment operation,
The home position is detected by detecting the position of the detected element f by the sensor g.

[0004]

In the above-described width adjustment mechanism, both racks h and i are fixed to width adjustment guides c and d, respectively, and both racks h and i are properly engaged with the pinion e. The intermediate tray a is slidably fitted to a guide member (not shown) so that the state is maintained.
The width adjustment guides c and d move according to the width of the paper conveyed to the printer, and the width adjustment is performed.

[0005] However, both racks h,
There is some play in both the meshing state of i and the sliding engagement state of the racks h and i with the guide member. Therefore, both width adjusting guides c and d swing by the amount of the play, but the swing width becomes larger toward the outer portion. Therefore, the position of the detected element f detected by the sensor g has a relatively large swing width and includes an error, and there is a problem that it is difficult to accurately detect the position of the home position.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a device that can accurately detect the position of a home position.

[0007]

According to the present invention, means for solving the above-mentioned problems are constituted as follows. That is, after forming an image on one side of a sheet, a pair of width adjustments interlocked with each other by a rack and a pinion mechanism are provided on both sides of an intermediate tray provided for temporarily storing the sheet until re-feeding the sheet. A guide is provided, and a detector for detecting the home position of each of the width adjustment guides is provided at a position on one of the width adjustment guides on the pinion axis.

[0008]

Since the detected element is provided at the position on the axis of the pinion, the swing width of the detected element is relatively small, and the accuracy of detecting the home position is significantly improved.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 to 3 show a width adjusting mechanism provided on an intermediate tray for temporarily stocking a sheet after forming a single-sided image. Reference numeral 1 denotes an intermediate tray, which is provided on a main body of a sheet feeding device 10 (see FIG. 4). It comprises a base plate 2 provided in a fixed state, and a push-up plate 3 whose leading end is lifted when refeeding paper. 4 and 5 are width alignment guides, 6
Is a rack and a pinion mechanism for moving the width adjusting guides 4 and 5, and comprises a pinion 7 and a pair of racks 8 and 9 that mesh with the pinion 7 in parallel with each other. Sliding contact is made with a groove-shaped guide member 11 fixed to the base plate 2, and each end of the guide member 11 is fixed to the width adjusting guides 4, 5, respectively. Are appropriately adjusted according to the width of the sheet.

More specifically, the width adjusting guides 4 and 5 are composed of bottom portions 41 and 51 arranged horizontally and rising edges 42 and 52 rising upward at the ends thereof.
The bases of the racks 8 and 9 are fixed to the screw holes formed in the screw holes 1 and 51 by the flathead screws 45 and 55, respectively.
Rollers 46 and 56 which are supported directly below 55
The rising edge portions 42 and 52 are projected upward from the notch portions 31 and 32 formed by cutting the both sides of the push-up plate 3, and one of the width adjusting guides 5 is formed. A detector 53 for detecting the home position is formed at a position on the axis G of the pinion 7 at the rising edge 52 of the base plate 2, and the position of the detector 53 is accurately determined by the sensor 12 provided on the side of the base plate 2. We make it easy to detect. Since the sensor escape hole 54 is formed immediately below the detected element 53, the moving distance of the width alignment guides 4 and 5 can be increased, and the apparatus can be made compact. Reference numerals 26 and 26 indicate rollers 4
Slots formed in the base plate 2 to allow the movement of 6, 56.

The above-described pinion 7 is configured to be rotationally driven by a motor 15 provided below the base plate 2 via a gear transmission mechanism.

As described above, the detected element 53 for detecting the home position of the width adjusting guides 4 and 5 is provided at the position on the axis G of the pinion 7 at the rising edge 52 of one of the width adjusting guides 5. By doing so, the swing width of the detected element 53 becomes relatively small, so that the accuracy of detecting the home position is significantly improved. That is, the roller 4 with respect to the guide groove 111 of the guide member 11
The width adjustment guides 4 and 5 slightly swing due to the play of the racks 6 and 56 and the play of the racks 8 and 9 with respect to the pinion 7, but the outer portion swings in a substantially arc shape, and the swing width at the front and rear ends thereof. Is large, while the swing width at the position of the detected element 53 is relatively small, so that the position of the home position can be accurately detected.

FIG. 4 shows the overall configuration of a copying machine (an example of an image forming apparatus) 60.
FIG. 5 shows the sheet feeding device 10. The copying machine 60 includes an image forming unit 62 having an image forming drum 61, an output unit 63 for outputting image forming information to the image forming unit 62, and a plurality of sheet cassettes 65, 66,
A paper feed path 68 for transporting a sheet of a predetermined size from 67 to the image forming unit 62, a paper feed path 70 for transporting the sheet after image formation to the fixing device 69, and a sheet after fixing to the discharge tray 71. A paper discharge path 72 for discharging, a paper feeder 10 suitable for producing a large number of double-sided images, and a path switching means 73 for switching and feeding paper to the paper feeder 10 and the paper discharge path 72 And

The paper, which has been copied on one side and introduced from the paper introduction unit 74, enters the intermediate tray 1 via the paper transport path 75 and the guide plate 79. When the trailing edge of the paper leaves the feed roller 22, the guide plate 79 is rotated counterclockwise, and width adjustment is performed by the width adjustment guides 4 and 5.

After the width adjustment, the forward feed roller 19 descends and feeds the sheet to the left in FIGS. Then, the sheet is guided by the guide plate 79 and is nipped by the roller 20 and the belt 21. The above operation is repeated each time a subsequent sheet enters the intermediate tray 1, and the sheet is stocked on the intermediate tray 1.

When the stock is completed, the feed roller 18 rotates counterclockwise in response to another signal, and the lowermost sheet is fed leftward in FIGS.

The sheets are separated by the rollers 20 and the belt 21 rotating in opposite directions, and are sent one by one to a sheet discharge path 78. After that, the sheet is sent to the image forming drum 61 via the sheet feeding path 68, is copied on both sides, and is discharged onto the sheet discharge tray 71.

[0018]

As described above, according to the home position detecting apparatus of the present invention, a pair of width adjusting guides are provided on both sides of the intermediate tray by a rack and a pinion mechanism. Since the detected element for detecting the home position is provided at a position on the pinion axis in one of the width adjustment guides, the swing width of the detected element is relatively small, and the position detection of the home position is performed. Accuracy is remarkably improved, and occurrence of image shift and jam can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of an intermediate tray showing one embodiment of a home position detecting device of the present invention.

FIG. 2 is a plan view of the width alignment guide.

FIG. 3 is a perspective view of the rack and a pinion mechanism.

FIG. 4 is a configuration diagram of the copying machine.

FIG. 5 is a configuration diagram of a main part of the copying machine.

FIG. 6 is a plan view showing an example of a conventional home position detecting device.

[Explanation of symbols]

1 ... Intermediate tray, 4,5 ... Width adjustment guide, 53 ... Detected element, 6 ... Rack and pinion mechanism, G ... Pinion axis.

Claims (1)

[Claims] A pair of racks and a pinion mechanism interlock with each other on both sides of an intermediate tray provided for temporarily storing a sheet until a sheet is re-fed after an image is formed on one side of the sheet. Home position detection, wherein a detector for detecting the home position of both width alignment guides is provided at a position on the pinion axis of one of the width alignment guides. apparatus.