JPH10279199A - Picture image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of jam by providing a difference in steps at a boundary between a part close to an insertion port of an insertion base and a part remote therefrom and blocking a space linked to the insertion port around the difference in steps by predetermined timing to prevent the reinsertion of a printed medium discharged from a paper discharge port into the insertion port in a tip part. SOLUTION: When a printed medium 12 is conveyed and a detection sensor 23 detects a tip part 12a thereof, a space linked to an insertion port 14 among spaces around a difference in steps 18c is blocked by a blocking member 24. Furthermore, if the printed medium 12 is discharged from a discharge port 16 and the tip part 12a of the printed medium 12 is curled due to its absorption of moisture, the tip part 12a thereof is put on an insertion base 18 again and is led into the insertion port 14 again due to the insertion of the printed medium 12. At this time, by blocking the space linked to the insertion port 14 by the blocking member 24, the tip part 12a of the printed medium 12 is stopped by the blocking member 24 to prevent its insertion into the insertion port 14 so that jam does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a copying machine, a printer, and a plotter.

[0002]

2. Description of the Related Art As an output device of a computer or a work station, an ink jet image forming apparatus for forming an image on a print medium by discharging ink, or an electrophotographic system for forming an image on a print medium using a developer or the like. Image forming apparatuses are known. In these image forming apparatuses, an insertion slot into which a print medium is inserted and a discharge slot from which the print medium is discharged are formed on the same side, and an insertion table for guiding the print medium to the insertion slot is arranged on this same side. There are things.

When a printing medium is inserted into the insertion slot and transported, the printing medium is placed on an insertion table and inserted into the insertion slot.
A detection sensor for detecting the print medium is arranged near the insertion slot, and the detection sensor detects the leading end of the print medium, and the conveyance roller starts rotating, so that the print medium is conveyed.

In an image forming apparatus provided with the above-mentioned insertion table and detection sensor, an image is sometimes formed on a print medium after measuring the length of the print medium.
Place the print medium on the insertion table, insert the print medium from the insertion slot, make the detection sensor detect the leading edge of the print medium, transport the print medium toward the paper exit, and detect the rear end of the print medium. To detect. The length of the print medium is measured by detecting the leading and trailing ends of the print medium with the detection sensor in this manner, and the print medium whose length has been measured is directed from the paper output port toward the insertion port (length). The print medium is conveyed in a direction opposite to the direction of the measurement and enters a print standby state, and the operation of setting the print medium ends.

However, when the discharge port is located above the insertion port and the print medium is long, the leading end of the print medium hangs down from the discharge port during the measurement of the length of the print medium, and the insertion base is lowered. May be inserted again into the insertion slot. In this case, the leading end of the print medium causes a paper jam (jam). Such a jam may occur when an image is formed on a long print medium.

[0006]

Therefore, in order to prevent such a jam, a guide or the like for guiding the print medium discharged from the paper discharge port to a position distant from the insertion port is provided.
The print medium is discharged to a position away from the insertion slot.

However, even if the print medium is ejected to a position distant from the insertion slot, the entire print medium is curled, or the leading end of the print medium is curled due to moisture absorption or the like. In some cases, the leading end of the print medium discharged from the paper discharge port is placed on the insertion table again and inserted into the insertion port, causing a paper jam (jam).

The present invention has been made in view of the above circumstances, and provides an image forming apparatus in which a leading end of a print medium discharged from a paper discharge port is prevented from being inserted again into an insertion port to prevent a jam. Aim.

[0009]

In order to achieve the above object, an image forming apparatus according to the present invention has an insertion opening into which a print medium is inserted and a discharge outlet from which the print medium is discharged, formed on the same side, In the image forming apparatus provided with an insertion table for guiding a print medium to the insertion port on the same side, (1) the insertion table has a step at a boundary between a portion near and far from the insertion port; (2) There is provided a closing member for closing a space around the step and connected to the insertion port at a predetermined timing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Here, an inkjet image forming apparatus is shown as an example of the image forming apparatus.

FIGS. 1 to 4 are schematic views showing a schematic configuration of an ink jet type image forming apparatus which is an embodiment of the image forming apparatus of the present invention. FIG. Here, a state is shown that is located at a portion far from the insertion opening. FIG. 2 shows a state immediately before the leading end of the print medium reaches the detection sensor of the paper discharge port, and FIG. FIG. 4 shows a state in which the leading end of the print medium placed on the insertion table is stopped by a closing member.

In the ink jet type image forming apparatus 10, an insertion slot 14 into which the print medium 12 is inserted and the print medium 1
The paper discharge port 16 from which the paper 2 is discharged is formed on the same side. Further, an insertion table 18 for guiding the print medium 12 to the insertion port 14.
Are disposed on the same side as the paper discharge port 16. Insertion table 18
Is composed of a portion 18a near the insertion port 14 and a portion 18b far from the insertion port 14, and the near portion 18a is more
About 5 mm lower. Therefore, a step 18c is formed at the boundary between the near portion 18a and the far portion 18b. Above the step 18c, a closing member 24 that closes, at a predetermined timing, a space connected to the insertion port 14 in the space around the step 18c is arranged. The closing member 24 will be described later with reference to FIGS.

In the vicinity of the insertion slot 14, a detection sensor (photo interrupter) 22 for detecting the print medium 12 is arranged. The detection sensor 22 allows the printing medium 12
Are detected, and the detection signal is processed by a computing unit (not shown) to measure the length of the print medium 12.

A detection sensor (photo interrupter) 23 for detecting the print medium 12 is disposed between the paper discharge roller 34 and the paper discharge port 16. The transport roller 32
A print head 40 that forms an image by ejecting ink while reciprocating in the direction perpendicular to the paper surface of FIG. The transport roller 26 is configured to be rotatable in directions indicated by arrows B and C.

Referring again to FIGS. 1 to 4, a procedure for forming an image on the print medium 12 using the ink jet type image forming apparatus 10 will be described.

When an image is formed on the print medium 12 by the ink jet type image forming apparatus 10, the print medium 12 is placed on a distant portion 18b of the insertion table 18 as shown in FIG. Insert the printing medium 12 into
The print medium 12 is brought into contact with the detection sensor 22. When the print medium 12 hits the detection sensor 22, the detection sensor 22
Of the print medium 12 is detected, and the transport roller 26 starts rotating (forward rotation) in the direction of arrow B. As a result, the print medium 12 is transported between the transport roller 26 and the guide plate 30 while being sandwiched between the transport roller 26 and the transport roller 28.

When further transported, as shown in FIG.
The print medium 12 is nipped by a pair of paper discharge rollers 34 and transported toward the paper discharge port 16. When the print medium 12 is further transported, as shown in FIG. 3, the leading end 12a of the print medium 12 is detected by the detection sensor 23. Timing at which the leading edge 12a of the print medium 12 is detected by the detection sensor 23 (an example of a predetermined timing according to the present invention)
Thus, of the space around the step 18c, the space connected to the insertion port 14 is closed by the closing member 24. This blockage will be described later with reference to FIGS.

As described above, the print medium 12 starts to be discharged from the paper discharge port 16 while the print medium 12 is held between the transport roller 26, the transport rollers 28 and 32, and the paper discharge roller 34. Here, if the leading end 12a of the print medium 12 is curled due to moisture absorption or the like, the leading end 12a is mounted on the insertion table 18 again as shown in FIG. The distal end portion 12a is guided to the insertion port 14 again.

However, at this time, since the space connected to the insertion port 14 among the spaces around the step 18c is closed by the closing member 24 as described above, as shown in FIG. The distal end portion 12a is stopped by the closing member 24 and is not inserted into the insertion port 14. Therefore, the discharge port 1
Since the leading end portion 12a of the print medium 12 discharged from 6 is not inserted into the insertion port 14 again, it is possible to prevent the occurrence of a jam.

The closing member 24 will be described with reference to FIGS.

FIG. 5 is a schematic view showing the closing member 24.
FIG. 6 is an enlarged view showing a state in which a space connected to the insertion port 14 in the space around the step 18 c is closed by the closing member 24.

The closing member 24 includes a motor 24a and a gear 24b fixed to a rotating shaft of the motor 24a, and a gear 24c meshes with the gear 24b. A closing plate 24d is fixed to the rotating shaft of the gear 24c.
It rotates in the direction D '. A transport roller 24e is rotatably fixed to the tip of the closing plate 24d.

After the printing medium 12 placed on the insertion table 18 (see FIG. 1) is inserted into the insertion port 14, the detection sensor 23
Until the print medium 12 is detected, the closing plate 24a is located at the position shown in FIGS. 1 and 2, and of the spaces around the step 18c, the space connected to the insertion port 14 is not closed. . However, the print medium 12 is detected by the detection sensor 23.
24c at the timing when the tip 12a of the motor 24c is detected.
Is rotated to rotate the closing plate 24d in the direction of arrow D, the transport roller 24e fits into the step 18c and is pressed down by a force enough to allow the print medium 12 to pass therethrough. The space connected to 14 is closed. As a result, as described above, for example, when the leading end portion 12a of the print medium 12 discharged from the paper discharge port 16 is curled, it is possible to prevent a jam without being inserted into the insertion port 14 again. Further, since the print medium 12 that is passing through the step 18c can pass along the step 18c, there is no problem in transporting the print medium 12. Here, the insertion table 1
8, the portion 18a near the insertion port 14 is
Although the height is about 5 mm lower than b, the converse may be such that the near part 18a is about 5 mm higher than the far part 18b.

[0024]

As described above, according to the image forming apparatus of the present invention, the space around the step and connected to the insertion port is closed by the closing member at a predetermined timing. For this reason, even if the leading end of the print medium discharged from the paper discharge port is curled, it is possible to prevent the jam from occurring without being inserted again into the insertion port. On the other hand, since the print medium passing through the step can pass along the step, there is no problem in transporting the print medium.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a state in which the leading end of a print medium is located in a portion of an insertion table that is far from an insertion slot.

FIG. 2 is a schematic diagram illustrating a state immediately before a leading end of a print medium reaches a detection sensor of a paper discharge port.

FIG. 3 is a schematic diagram illustrating a state in which a print medium hangs from a paper discharge port.

FIG. 4 is a schematic diagram illustrating a state in which a leading end of a print medium placed on an insertion table is stopped by a closing member.

FIG. 5 is a schematic view showing a closing member.

FIG. 6 is an enlarged view showing a state in which a space connected to an insertion port in a space around a step is closed by a closing member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Print medium 14 Insertion opening 16 Paper discharge opening 18 Insertion stand 18a Portion of the insertion stand near the insertion opening 18b Portion of the insertion stand far from the insertion opening 18c Step 24 Closing member 24d Closing plate

Claims (1)

[Claims] 1. An image forming apparatus, comprising: an insertion slot into which a printing medium is inserted; and a paper ejection slot from which the printing medium is discharged, formed on the same side, and an insertion table for guiding the printing medium to the insertion slot. In the device, the insertion table has a step at a boundary between a portion near the insertion port and a portion far from the insertion port, and around the step, a closing member that closes a space connected to the insertion port at a predetermined timing. An image forming apparatus comprising: