JPH0746924Y2 - Document carrier sheet for image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a document carrier sheet for an image forming apparatus,
More specifically, the present invention relates to a document carrier sheet for an image forming apparatus for conveying a document to a document reading unit in an image forming apparatus such as a copying machine or a facsimile.

(B) Problems to be Solved by Conventional Techniques and Inventions In general, such a document carrier sheet for an image forming apparatus supports a rectangular transparent sheet portion that supports a surface to be read of a document and another surface of the document, It consists of a sheet part having substantially the same shape as the transparent sheet part, and a connecting part for connecting the leading edges of the two sheet parts in the transport direction. In addition to a normal original document, an ultra-thin sheet, a small sheet, and a special shape. It is used to hold a document such as a sheet of the above-mentioned sheet between both sheet parts and convey it to the document reading part of the image forming apparatus.

However, when carrying such a document using a carrier sheet, compared to the case where only the document is carried,
There is a possibility that the timing of the leading edge of the image forming apparatus may be different and the position of the formed image may be displaced. In other words, the document is read by detecting the leading edge of the document with a switch provided near the transport roller, and after a certain period of time from the detection, the switch detects the leading edge of the document itself when only the document is transported. Therefore, the document is read from a predetermined position. However, when the original is conveyed using the carrier sheet, the switch detects the front end of the carrier sheet rather than the front end of the original, so that reading may not be performed from a predetermined position on the original, and the image forming position may be displaced. That is why.

For example, with the carrier sheet ca shown in FIG. 4, the document is read at the leading edge of the carrier sheet ca, that is, both sheet portions 1
There is a possibility that the tip of the joint portion 4a of a and 2a is detected by a switch as appropriate, a predetermined time has elapsed after the detection, and therefore the original 3a is not detected from a predetermined position. In addition, 6a in FIG.
Indicates an end side of the connecting portion 4a in the reverse transport direction, and 5a ... Only projecting pieces formed to project from the tip of the carrier sheet ca to prevent positional deviation (see Japanese Utility Model Laid-Open No. 58-170641).

Of course, the above-mentioned misregistration in image formation occurs because the reading detects not the leading edge of the document but the leading edge of the carrier sheet. This can be achieved by switching and shifting the reading time by the length of the direction). However, for that purpose, a changeover switch and a control device are separately required, which increases the cost and complicates the operation.

Furthermore, even if the carrier sheet is used as described above, even if the reading timing of the original can be shifted, the leading edge of the original does not exactly contact the edge of the joint portion of both sheet portions. , Rarely in the normal case, and eventually
Resolving misregistration in image formation has been a difficult problem.

This invention was made in order to solve the above problems, and the reading of the original is started from a predetermined position of the original,
An object of the present invention is to provide a document carrier sheet that can prevent the shift of the image forming position.

(C) Means and Actions for Solving the Problem This invention has a rectangular transparent sheet portion that supports the surface to be read of an original document, and a sheet portion that supports the other surface of the original document and has a substantially same shape as the transparent sheet portion. In a document carrier sheet for an image forming apparatus, which comprises a joining portion that joins the leading edges of these two sheet portions in the carrying direction, a sheet is formed deeper than the depth of the joining portion from the leading edge of the carrier sheet in the carrying direction, and between the two sheet portions. The image forming apparatus has a notch for detecting the leading edge of the sandwiched document in the conveying direction, and a plurality of these notches are formed at intervals in the width direction of the sheet and correspond to the usable document size. And a document carrier sheet for an image forming apparatus in which a combination of notches in which a front end of a document projects is different.

That is, this invention uses a carrier sheet by forming a specific notch deeper than the depth of the joint portion of both sheet portions from the leading end of the carrier sheet in the conveying direction,
Attach the leading edge of the document itself that is nipped between both sheet
The image can be detected by the image forming apparatus, so that the reading of the document is started from a predetermined position of the document and the shift of the image forming position can be prevented.

Further, a plurality of the above-mentioned notches are formed at intervals in the width direction of the sheet, and the combination of the notches in which the leading edge of the original document projects is different according to the usable original size. The document size can be determined by detecting the combination with the image forming apparatus. That is, the document size can be automatically determined with the common carrier sheet without using the carrier sheet corresponding to the document size.

(D) Examples The present invention will be described in detail based on the reference examples and examples shown in the drawings. The invention is not limited to this.

First, referring to FIGS. 1 and 2 showing a reference example, a facsimile original carrier sheet C includes a rectangular transparent sheet portion 1 for supporting a surface to be read of an original 3 and another sheet 3 for supporting the other surface of the original 3. Opaque (white) sheet part 2 of almost the same shape
And a joining portion 6 for joining the leading edges of the two sheet portions in the transport direction.

Reference numeral 7 is a notch formed from the leading end 4 of the carrier sheet C in the conveying direction, and the depth thereof is deeper than that of the joint portion 6. Therefore, when the rectangular original 3 is normally sandwiched between the two sheet portions 1 and 2 of the carrier sheet C so that the leading edge of the original 3 abuts on the trailing edge of the connecting portion 6, the leading edge of the original 3 is A part (3b, central portion in the width direction) is exposed from the notch 7 in the transport direction.

Thus, the carrier sheet C containing the document 3 placed on the document table 10 of the facsimile F is transported in the transport direction H by the transport rollers 9 and 9b. At this time, the lever 8b of the document leading edge detection switch 8 comes into contact with not the carrier sheet C but the edge 3b of the document 3 exposed from the cutout 7 to activate the detection switch 8, and after a predetermined time (for example, After 3 seconds), the information on the original 3 is read, and the carrier sheet C is appropriately ejected by the ejection rollers 11 and 11b. The original 3 is read by the illumination lamp 12, the mirror 13 and the sensor.
The information (optical information) read and performed by 14 is appropriately converted into an electric signal and transmitted to the receiver on the other side.

As described above, since the carrier sheet C is formed with the notch 7 deeper than the connecting portion 6 at the leading end in the transport direction, the document leading edge detection switch 8 of the facsimile F does not affect the leading edge of the carrier sheet C but the document 3 itself. Can detect the tip side,
As a result, the reading of the original 3 is started from a predetermined position of the original, and it is possible to prevent the deviation of the image forming position of the other party who receives the read information. Further, when the carrier sheet C is used, a changeover switch and a control device for adjusting the deviation of the leading edge timing between when only the original is used and when the carrier sheet is used are unnecessary.

Now, in the embodiment of this invention, unlike the above reference example,
It is also possible to form a plurality of notches in the carrier sheet at intervals in the width direction of the sheet as shown in FIG. That is, in FIG. 3, the carrier sheet 20c has two notches 27, 27b deeper than the joint portion 26 at the leading end in the transport direction,
The document edge detection switches 28b and 28c of the facsimile 20F are installed in correspondence with the notches 27 and 27b. When the original 23 of the original size A4 is intervened at a predetermined position on the carrier sheet according to the instruction, the leading edge of the original 23 projects only from the notch 27, and in the case of the original 23b of the original size A3, both notches 27 ... The leading edge of the original 12 is configured to protrude from 27b.

Thus, when the detection timings of the originals are simultaneously detected by the detection switches 28b and 28c, the document size is A3, and when the detection timings of the originals are deviated, that is, the detection switch 28c detects the original first. Then, when the detection switch 28b detects the cutout (bottom side) of the carrier sheet, it can be determined that the size of the document is A4. Of course, those detection switches 28b and 28c
In any case, since the document leading edge itself is used to detect the document, the leading edge timing can be accurately set.

In summary, when a plurality of cutouts are formed at a specific position in the width direction of the sheet, the document size is determined by the combination of the detection timings, for example, the document sizes A3 and B.
4, A4 and B5 etc. can be distinguished. Thus, it is not necessary to prepare a carrier sheet for each document size, and the document size can be detected by using a common carrier sheet. If these configurations are adopted in an image forming apparatus having a function of automatically selecting a sheet cassette or changing a magnification according to a document size detection signal, these functions are linked with the document size detection function. It is very effective because it can be done.

In this invention, the notch formed at the leading end of the carrier sheet in the conveying direction is deeper than the depth of the joint portion of both sheet portions, specifically, the depth of the joint portion is, for example, 5 to 10 mm, and more preferably than that depth. 5-15mm, more preferably about 10mm
The depth is set so that the front side of the document is always exposed from the notch in the conveyance direction by a normal operation of sandwiching the document on the carrier sheet. The width of the notch is usually preferably 20 to 50 mm, more preferably 30 to 40 mm. Of course, the widthwise position of such a notch on the carrier sheet is determined corresponding to the lateral position of the document leading edge detection switch of the image forming apparatus.

In this invention, the joint portion of both sheet portions may be formed by appropriately joining both sheet portions with an adhesive layer as in the embodiment, but both sheet portions are formed by one sheet material and are bent. May be. In this case, the connecting portion is a bent portion.

(E) Effect of the Invention According to this invention, by forming a specific notch deeper than the depth of the joint portion of both sheet portions from the leading end of the carrier sheet in the conveying direction, the carrier sheet is used and the space between both sheet portions is formed. The image forming apparatus can detect the leading end of the sandwiched document itself in the conveying direction, whereby reading of the document is started from a predetermined position of the document, and deviation of the image forming position can be prevented.

Further, a plurality of the above-mentioned notches are formed at intervals in the width direction of the sheet, and the combination of the notches in which the leading edge of the original document projects is different according to the original size. The size of the document can be determined by detecting it with the forming device. That is, the document size can be automatically determined with the common carrier sheet without using the carrier sheet corresponding to the document size.

[Brief description of drawings]

FIG. 1 is a perspective view showing a reference example of a document carrier sheet in a state of use, FIG. 2 is a longitudinal sectional view showing a state of use, and FIG. 3 is a view corresponding to FIG. The figure is a perspective view showing a conventional document carrier sheet. 1 ... Square transparent sheet part, 2 ... Sheet part, 3 ... Original, 6 ... Combining part, 7 ... Notch, 8 ... Detection switch,
F: Facsimile, C: Carrier sheet.

Claims (1)

[Scope of utility model registration request] 1. A rectangular transparent sheet portion for supporting a surface to be read of a document, a sheet portion for supporting the other surface of the document, and a sheet portion having substantially the same shape as the transparent sheet portion, and front end edges of these sheet portions in a transport direction. In the original carrier sheet for the image forming apparatus, which is formed by a joining portion that joins the sheets, the leading edge in the feeding direction of the original sheet that is formed deeper than the depth of the joining portion from the leading edge of the carrier sheet in the feeding direction is imaged. Has a notch to detect with the device,
Further, an image formation characterized in that a plurality of these notches are formed at intervals in the width direction of the sheet, and the combination of the notches in which the leading end of the original document projects is different according to the usable original size. Original document carrier sheet.