JP3639429B2 - Home position detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus for performing, for example, double-sided copying for forming images on both sides of a sheet, multiple copying for copying a plurality of originals on a single sheet, and multicolor copying for coloring a plurality of colors. The present invention relates to a device for detecting a home position of a width alignment guide of an intermediate tray provided.
[0002]
[Prior art]
The intermediate tray provided in a copying machine or the like capable of duplex copying is stored in a stacked state until an image is formed on one side of the paper and then the paper is re-feeded. The width alignment of the stacked sheets is performed by the width alignment guides provided on both sides of the intermediate tray.
[0003]
For example, as shown in FIG. 6, the width adjusting mechanism of the 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 drive source (not shown) that drives the pinion e. The width adjusting guide d includes a detected element f projecting from one end of the width adjusting guide d, a sensor g for detecting the detected element f, and the like. Is automatically adjusted. Prior to the adjustment operation, the home position is detected by detecting the position of the detected element f by the sensor g.
[0004]
[Problems to be solved by the invention]
In the width adjusting mechanism as described above, both racks h and i are fixed to the width adjusting guides c and d, respectively, and the racks h and i are guided so as to maintain an appropriate meshing state with the pinion e. Both width alignment guides c and d are moved in accordance with the width of the paper carried into the intermediate tray a by sliding contact with a member (not shown), and the width alignment is performed.
[0005]
However, there is some play in both the engagement state of the racks h and i with respect to the pinion e and the sliding contact engagement state with the guide members of the racks h and i. Accordingly, the width adjusting guides c and d swing by the amount of play, but the swinging 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.
[0006]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an apparatus that can accurately detect the position of a home position.
[0007]
[Means for Solving the Problems]
In the present invention, means for solving the above-described problems are configured as follows.
That is, after forming an image on one side of the sheet, at both sides of the intermediate tray provided to temporarily housed until the refeeding the sheet, mutually viewed engage parallel to each other for one of the pinion A pair of width alignment guides that are linked to each other by a pair of racks and a pinion mechanism are provided, and a detector for detecting the home position of the both width alignment guides is provided in one of the width alignment guides , and the pinion And a guide member that is slidably fitted to the rack and the detected element are arranged in a straight line on the pinion axis .
[0008]
[Action]
By arranging the pinion, the guide member slidably fitted to the rack, and the detected element so as to be arranged in a straight line on the pinion axis , the swing width of the detected element is relatively small. Therefore, the accuracy of detecting the home position is remarkably improved.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
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 in an intermediate tray for temporarily stocking paper after single-sided image formation. Reference numeral 1 denotes an intermediate tray, which is attached to the main body of the paper feeder 10 (see FIG. 4). It consists of a base plate 2 provided in a fixed state and a push-up plate 3 whose tip is raised during refeeding. 4 and 5 are width alignment guides, 6 is a rack and pinion mechanism for moving the width alignment guides 4 and 5, and includes a pinion 7 and a pair of racks 8 and 9 that mesh with the pinion 7 in parallel with each other. The racks 8 and 9 are slidably fitted into groove-shaped guide members 11 fixed to the base plate 2, and their end portions are fixed to the width adjusting guides 4 and 5, respectively. By rotation, the distance between the width adjusting guides 4 and 5 is appropriately adjusted according to the width of the paper.
[0010]
More specifically, the width adjusting guides 4 and 5 are composed of bottom portions 41 and 51 arranged horizontally and rising side portions 42 and 52 rising upward at the ends thereof, and screws formed on the bottom portions 41 and 51. The bases of the racks 8 and 9 are fixed to the holes by the countersunk screws 45 and 55, and the rollers 46 and 56 pivotally supported directly below the countersunk screws 45 and 55 are slidably fitted into the guide grooves 111 of the guide member 11. On the other hand, the rising edges 42 and 52 protrude upward from the notches 31 and 32 formed on both sides of the push-up plate 3, and the axis G of the pinion 7 at the rising edge 52 of the width adjusting guide 5. A detection element 53 for detecting the home position is formed at the upper position, and the position of the detection element 53 can be accurately detected by the sensor 12 provided on the side portion of the base plate 2. 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 are long holes formed in the base plate 2 to allow the rollers 46 and 56 to move.
[0011]
The above-described pinion 7 is configured to be rotationally driven by a motor 15 provided under the base plate 2 via a gear transmission mechanism.
[0012]
As described above, the detected element 53 for detecting the home position of the both width alignment guides 4 and 5 is provided at the position on the axis G of the pinion 7 in the rising side portion 52 of one width alignment guide 5. As a result, the swing width of the detected element 53 becomes relatively small, so that the accuracy of detecting the position of the home position is remarkably improved. That is, the width adjusting guides 4 and 5 are slightly swung by the play of the rollers 46 and 56 with respect to the guide groove 111 of the guide member 11 and the play of the racks 8 and 9 with respect to the pinion 7, but the outer portion thereof has a substantially arc shape. While the swinging width is large at the front and rear ends thereof, the swinging width is relatively small at the position of the detected element 53, so that the position of the home position can be accurately detected.
[0013]
The other parts will be described. FIG. 4 shows the overall configuration of a copying machine (an example of an image forming apparatus) 60, and FIG. The copier 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 paper feed cassettes 65, 66, 67. A paper feed transport path 68 for transporting the sized paper to the image forming unit 62, a paper feed transport path 70 for transporting the paper after image formation to the fixing device 69, and a paper discharge for discharging the paper after fixing to the paper discharge tray 71. A paper path 72; a paper feeding apparatus 10 suitable for creating a large number of double-sided images; and a path switching means 73 for switching and feeding paper to the paper feeding apparatus 10 and the paper discharge path 72. ing.
[0014]
Then, the sheet that is copied on one side and introduced from the sheet introduction section 74 enters the intermediate tray 1 through the sheet conveyance path 75 and the guide plate 79, and the guide plate 79 is counteracted when the trailing edge of the sheet leaves the feed roller 22. While rotating clockwise, width alignment is performed by the width alignment guides 4 and 5.
[0015]
After the width adjustment is performed, the forward feed roller 19 descends and feeds the paper in the left direction in FIGS. The sheet is guided by the guide plate 79 and 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.
[0016]
When the stocking is completed, the feeding roller 18 is rotated counterclockwise by another signal, and the lowermost sheet is fed leftward in FIGS.
[0017]
Then, the paper is separated by the rollers 20 and the belt 21 rotating in the opposite directions, and sent one by one to the paper carry-out path 78. Thereafter, the sheet is sent to the image forming drum 61 through the sheet feeding / conveying path 68 to be copied on both sides, and then discharged onto the sheet discharge tray 71.
[0018]
【The invention's effect】
As described above, according to the home position detection device of the present invention, the pair of width alignment guides that are interlocked with each other by the pair of racks and the pinion mechanism that mesh with each other in parallel with the one pinion are provided on both sides of the intermediate tray. And a detecting member for detecting the home position of the both width adjusting guides is provided in any one of the width adjusting guides , and the pinion, a guide member slidably fitted to the rack, and a detected object Since the elements are arranged in a straight line on the pinion axis, the swing width of the detected element is relatively small, the position detection accuracy of the home position is remarkably improved, and image misalignment or jamming occurs. Can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view of an intermediate tray showing an embodiment of a home position detection device of the present invention.
FIG. 2 is a plan view of the same width alignment guide.
FIG. 3 is a perspective view of the rack and pinion mechanism.
FIG. 4 is a configuration diagram of the copier.
FIG. 5 is a main part configuration diagram of the copier.
FIG. 6 is a plan view showing an example of a conventional home position detection device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Intermediate tray, 4, 5 ... Width alignment guide, 53 ... Detector, 6 ... Rack and pinion mechanism, G ... Pinion axis

Claims (1)

A pair of racks that mesh with each other in parallel with one pinion on both sides of an intermediate tray that is provided to temporarily store the paper until it is re-fed after the image is formed on one side of the paper. A pair of width alignment guides interlocked with each other by a pinion mechanism, a detection element for detecting a home position of both width alignment guides is provided in one of the width alignment guides , and the pinion and the rack A home position detecting device, characterized in that a guide member that is slidably fitted to the guide member and a detected element are arranged so as to be aligned in a straight line on the pinion axis .

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