JPS61217463A - Intermediate tray of image forming apparatus - Google Patents

Abstract

PURPOSE:To reduce the contacting resistance between a copy paper and a guide thus to prevent jamming in the tray due to collapse of paper by carrying a large size copy paper between a pair of parallel guides then between oblique guides and passing through the narrow portion. CONSTITUTION:When setting the gaps L1, L2...Ln between a pair of parallel guides 27, 28 wider by about 1mm than the widths l1, l2...ln of the copy paper, the shifting amount of image on the back face will be within allowable range irrespectively of the size of the copy paper. In case of a copy paper having short length and width, it is mounted smoothly in an intermediate tray along the short limiting faces of the parallel guides 27, 28 as conventionally while in case of a copy paper having long length and width, it will only contact at the side portion against the short limiting faces of the parallel guides 27, 28 and the narrow sections 29, 30 of the oblique guides thus to reduce the contacting resistance of the entire guide resulting in prevention of curling of paper due to collapse.

Description

Detailed Description of the Invention (a) Industrial Applicability The present invention forms an image via an optical system that automatically copies on both sides or in multiple layers of a sheet such as transfer paper, or an electronic signal from an optical system. The present invention relates to an image forming apparatus (hereinafter simply referred to as a copying apparatus), and specifically relates to an intermediate tray for temporarily storing sheets whose one side has been copied.

(b) Conventional technology Sheets such as transfer paper (hereinafter simply referred to as transfer paper) automatically
A double-sided copying device that forms images on both the front and back sides of a transfer paper, after completing the first copy on the front side of the transfer paper, reverses the front and back sides, stores it on an intermediate tray, and copies the back side (second time). ) When the command is received, the transfer paper on the intermediate tray is carried out to the image forming mechanism again. However, when loading and storing the transfer paper on the intermediate tray, if the transfer paper is not loaded accurately at the predetermined position, the back side may be In some cases, an image to be copied may be copied at a misaligned position, so it is important to stack the transfer paper at a predetermined position on the intermediate tray in a double-sided copying device. Similarly, when performing multiple copying in which many copies are made on one surface, it is important to accurately stack the transfer paper at a predetermined position on the intermediate tray.

Here, an intermediate tray for temporarily storing and loading transfer paper in a conventional copying machine will be described with reference to FIGS. 4 and 5.

Transfer paper P, P after copying the front side (first time)
,, P2 is carried into the intermediate tray C (arrow A) by the intermediate paper feed roller a and the intermediate paper feed driven roller b in pressure contact with the intermediate paper feed roller a, and is fixed to the side edges of the transfer papers P, Pi, and P2. a reference guide d having a controlled surface; a transfer paper P;
The sheets are loaded at a predetermined position on the intermediate tray C by a moving guide e that moves to a predetermined position corresponding to the size of P, , P2. Then, when copying the back side (second time) is started, the transfer paper at the lowest position of the tray is moved by the semicircular auxiliary feed rollers f and g to the refeed roller (not shown) located below the intermediate paper feed roller a. However, - symbol 21 in Figure 3
).

→ Problem to be solved by the invention By the way, in the above-mentioned conventional example, the moving guide d is
Transfer paper p, p2. ...corresponding to the size of Pu,
The gap with the reference guide d is Ll, L2. The pair of guides d is moved and set to the position L, .

e, gap e', L2. -L, and transfer paper 1. ．． 12
The difference between ゜...l, -11, L2-12. ...-L
, -1,l is smaller, the transfer paper P, P,
, P2 are accurately placed in the predetermined position on the intermediate tray C, and the amount of lateral deviation of the copied image is reduced. However, on the other hand, the smaller the difference, the more the transfer paper P moves into the gaps between the guides d, e, and e' in the intermediate tray.

It becomes difficult to load paper P,, P2, and especially with large size transfer paper P1, the contact area between the side edge of the paper and guides d and e increases, and the contact resistance increases, so the paper may bend. As a result, the transfer paper curls in the intermediate tray C, resulting in poor stacking and paper jams.

Therefore, usually, the above difference is -1,,L2-12・
...L, -1,,, is set to about one cabinet, but this value is within the allowable range where the horizontal deviation of the image does not cause any problems when copying the back side (second time), and Transfer paper P
, P, , P2 is set so that it can normally be easily carried and loaded into the gap between the guides.

However, even with this level of value, there is a problem that paper jams as described above may occur in large-sized transfer paper.

To deal with this problem, when the transfer paper is carried into the intermediate tray, the above difference L1-1. ．． L2-1 ・
...L -1 is increased to prevent the paper from curling, and after the transfer paper is loaded, -1,, L2-12...
There is also a known copying device that reciprocates the moving guides e and e' to correct the loading position by reducing L, -1, but such a device is expensive due to its complicated mechanism. However, there were problems such as a short service life of the device.

(b) Means for Solving the Problem The present invention aims to solve the above-mentioned problems, and as shown in FIG. A parallel guide 27° 28 having a pair of short regulating surfaces parallel to the paper moving direction, and a parallel guide 27° 28 located behind the parallel guide 27° 28 with respect to the loading/unloading side and having an opening with respect to the transfer paper loading direction. It has a pair of restricting surfaces oriented obliquely so that the restricting surfaces have a pair of constricted portions 29 and 30 where the rearmost gap between the restricting surfaces is the smallest, and the gap between the pair of constricted portions is the parallel guide 27. The intermediate tray 18 is provided with oblique guides 31 and 32 that approximately correspond to the gap between the regulating surfaces of 28.

(e) Operation Based on the above-described configuration, transfer paper, especially large-sized transfer paper, is first carried into the gap between the pair of parallel guides 27 and 28, and then carried into the oblique guides 31 and 32. The fins 29 and 30 of the diagonal guide allow the transfer paper to be accurately loaded and stored at a predetermined position on the intermediate tray 18 while reducing the contact resistance between the side edge of the transfer paper and the entire guide. At the second time, the position is regulated by parallel guides 27 and 28 on the same side as the one on which it was carried in, and it is carried out.

(F) Example Hereinafter, an example of the present invention will be explained based on the drawings. An outline of a double-sided copying apparatus to which the present invention is applied will be explained based on FIG. 3. The transferred paper P copies an image (1
The transfer paper from the paper deck 3 is conveyed to the image forming section by the registration roller 4 (the transfer paper on the paper deck 3 is transferred via the fourth conveyance roller 26). In the image forming section, a latent image forming mechanism 5 comprising an optical system or the like forms a latent image on a photosensitive drum 6, a developing device 7 develops a toner image, a transfer section 8 transfers this image onto a transfer paper, Further, the toner remaining on the photosensitive drum 6 is removed by a cleaner 9. The transfer paper that has passed through the image forming section is transferred to the transfer paper conveyance section 1.
0, the image is fixed on the transfer paper using heat or pressure from a fixing device 11, and the image is fed to the deflection plate 12. Deflection plate 1
In case 2, the transfer paper is ejected to the ejection tray 13 when only one-sided copying and when double-sided copying is completed, but in the case of a transfer paper where only the front side has been copied (the first time) in double-sided copying. Then, the discharged paper is transported to the paper transport section 14. The transfer paper conveyed to the discharge paper conveyance section 14 is reversed by the belt conveyance section 15, the intermediate paper feed roller 16, and the intermediate paper feed driven roller 4 17 in pressure contact therewith, and then transported to the intermediate tray 18 and stacked thereon. Ru.

The transfer paper P loaded on the intermediate tray 18 is stored and temporarily waited for copying the back side (second time). In the back side copying process, first, the lowest transfer paper of the stacked transfer paper is transferred to the next process one by one by the auxiliary feed rollers 19 and 20 from the paper refeed roller 21 and the separation roller 22. After that, the first conveying roller 23, the second W1 conveying roller 24, and the third W1 conveying roller 2
5 and the fourth conveyance roller 26 to the registration roller 4, and thereafter the image is copied on the back side (second time) by the same process as the front side copy (first time), and the deflection plate 1
2, the paper is ejected to the paper ejection tray 13, and double-sided copying is completed.

Next, regarding the intermediate tray 18, FIGS.
This will be explained in detail based on the diagram.

The intermediate tray 18 has an intermediate paper feed roller 16 for carrying in the paper.
and a parallel guide 27.2 which is parallel to the moving direction of the transfer paper P (arrow A in the drawing) and has a pair of short regulating surfaces at a position close to the paper refeed roller 21 for ejection.
8 are provided, and each of the above-mentioned rollers 16, 21
It is located behind the parallel guide 27, 28, is open in the transport direction of the transfer paper P (arrow A), and has a pair of diagonal regulating surfaces having a constricted portion 29, 30 at the rearmost part. Diagonal guides 31, 32 are provided. The distance between the pair of parallel guides 27 and 28 is L2.
...L,, corresponds to the size of the transfer paper, one guide 2
8 are moved in parallel as shown by the chain line 28' and set at a predetermined position, and the gap between them is usually equal to the width 1.8 of the transfer paper. ．． 1
The distance is set to be about 1 mm wider than 2...l. On the other hand, one of the diagonal guides 31 and 32, as shown by the chain line 32', moves the movable parallel guide 32
8, the narrowest part of the gap between the oblique guides 31 and 32 forms constrictions 29, 30, 30', and the gap is on the extension of the regulating surface of the parallel guides 27, 28, 28'. Yes, the gap is the gap between the parallel guides 27, 28, 28'.

L2 .

In addition, a pair of parallel guides 27 and 28 and a diagonal guide 3
The guides 27 and 31 on one side of 1 and 32 are fixed so as to serve as a paper reference on one side, and the guides 28 and 3 on the other side
2 is integrally molded to form a moving guide portion. This guide 28. :(The set position of the movement guide section consisting of 2 is determined by moving the position indicating member 33 to the home position sensor
The reference position is set by detecting the reference position, and is further set by moving the movement guide part by a predetermined amount along the cutout part 35 using a drive device (not shown).

Further, when receiving an instruction to copy the back side (second time), the semicircular auxiliary feed roller 20 directly connected to the gear 36 is rotated by the drive of a drive source (not shown), and the pulley 37,
The other auxiliary feed roller 19 also rotates synchronously via the timing belt 38 and pulley 39, and transfers the lowest transfer paper stacked on the intermediate tray 18 one by one to the paper refeed roller. Carry it out.

In this embodiment, by having the above structure, the distance between the pair of parallel guides 27 and 28 is 1 m! L1. ζ・・Lu
The width of the transfer paper 1. ．． 12−...l, than 1+ma(L
.

-1,,L2-12...L,l-1,), the amount of misalignment of the image when copying the back side (second time) will be reduced by the difference in the size of the transfer paper, l,,12・Regardless of lu, if the transfer paper is within the allowable range and has a small width (12) and is relatively short in height, the transfer paper should be moved along the short regulating surfaces of the parallel guides 27 and 28 as before. The side edges of the transfer paper are stacked smoothly in the intermediate tray, and the width is thick.
7.28 short regulating surface and diagonal guide constriction 2
9.30, the contact resistance of the guide as a whole is reduced, and the paper is prevented from curling due to bending.

In the intermediate tray guide of the above embodiment, the copying apparatus has been described in which the guides 27 and 31 on one side are fixed and the paper reference is on one side, but in the present invention, the guides on both sides are movable and serve as the center paper reference. Of course, the present invention can be applied to a copying apparatus (in the above embodiment, the guides 27 and 31 also move). Further, although the description has been made regarding a double-sided copying apparatus, the present invention can be similarly applied to a case where multiple copies are performed.

(G) As described in detail, according to the present invention, the parallel guide 27.
28 and skew guides 31 and 32, there is no misalignment of the image even during second and subsequent copying, and it reliably prevents stacking errors due to paper curling in the intermediate tray. Furthermore, since the structure is simple, it is inexpensive and robust.

[Brief explanation of drawings]

1 to 3 are views showing an embodiment to which the present invention is applied, in which FIG. 1 is a perspective view of an intermediate tray of a double-sided copying machine, and FIG.
3 is a schematic side view showing the entire double-sided copying apparatus, FIG. 4 is a perspective view of a conventional intermediate tray, and FIG. 5 is a front view thereof. 18... Intermediate tray, 27, 28... Parallel guide, 29, 30... - Neck part, 31° 32
...Diagonal guide, P...Sheet (transfer paper).

Claims (1)

[Claims] (1) An intermediate tray of an image forming apparatus on which transferred sheets are loaded and the stacked sheets are carried out for transfer again, which is close to the sheet loading/unloading side and parallel to the sheet moving direction. a parallel guide having a pair of regulating surfaces; and a pair of regulating surfaces located behind the parallel guide with respect to the carry-in/out side and obliquely opening with respect to the sheet carrying direction; A diagonal guide having a constricted portion where the rearmost gap between the regulating surfaces is the smallest, and a gap between the opposing constricted portions substantially matching the gap between the regulating surfaces of the parallel guide. An intermediate tray of an image forming apparatus.