JP2556519B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly, to a method for conveying recording paper of a recording apparatus capable of double-sided or multiplex recording in an electrophotographic apparatus or the like. .

[Prior Art] Generally, when performing double-sided recording or multiplex recording in a laser printer or a copying machine, after recording the first image, the recording paper is recirculated (circulated) to the recording unit to record the second image. The method of doing is taken. In this method,
While the recording sheet on which the first image is recorded is conveyed along the sheet conveying path toward the recording section to receive the recording of the second image, the recording sheet is misaligned in the direction perpendicular to the conveying direction. Therefore, before the second image recording is performed, the work of correcting the positional deviation of the recording paper in that direction (hereinafter referred to as lateral registration adjustment) is performed in the apparatus. FIG. 4 shows an example of a laser printer having such a conventional lateral registration adjusting mechanism, and FIG. 5 shows the flow of recording paper in the printer of FIG. 4 as seen from above.

The printer 1 in FIG. 4 is a printer capable of double-sided recording. The recording paper 3 stored in the paper feed cassette 2 is fed by the paper feed roller 4, and the laser printer 5
After the timing with the image is taken in, the recording unit 6 records the first image. The recording unit 6 is composed of an optical recording unit, a photoconductor, a developing unit, a transfer unit, a cleaner unit, and the like for directly forming and recording an image.

The recording paper 3 on which the first image is recorded is the fixing roller 7
After being fixed by, the sheet passes through the fixing paper discharge roller 8 and is guided to the forward / reverse roller 10 by the flapper 9. The forward / reverse rotation roller 10 shifts the recording paper to guide it to the double-sided conveyance roller 11. Reference numeral 12 is a horizontal registration roller. The lateral registration roller 12 is for carrying out lateral registration adjustment before the recording paper 3 receives the second image recording and for conveying the recording paper 3 to the registration roller 5. Double-sided transport roller 11
When the recording paper 3 is conveyed from the horizontal registration roller 12
Moves reciprocally in the axial direction with the recording paper sandwiched, as shown in FIG. A sensor 13 is located near the lateral registration roller 12.
Is provided, and the sensor 13 detects the paper edge 3a of the recording paper 3. When the paper edge 3a moved by the reciprocal movement of the lateral registration roller 12 reaches the designated paper edge position of the recording paper size, the sensor 13 outputs a signal to stop the reciprocal movement of the lateral registration roller 12, Adjust the lateral registration by aligning the paper edge with the same position as the paper edge position when the image was recorded. The recording paper 3 for which the lateral registration adjustment has been completed is sent to the registration roller 5 by the lateral registration roller 12 as it is, and the second image is recorded on the back surface by the recording unit 6 in the same procedure as when the first image is recorded. To be done. After that, the recording paper 3 is fixed again by the fixing roller 7, guided by the flapper 9 to the paper discharge roller 13 ′, discharged onto the paper discharge tray 14 and stacked.

A drawback of such a conventional printer 1 is that the lateral registration adjusting mechanism is complicated and costly. For example, although not shown in the figure, the lateral registration roller 12 rotates and reciprocates, so that it must have a complicated cam structure for moving the rotating object in the axial direction. The recording paper 3 accommodated in the paper feed cassette 2 is usually used in several types from the maximum size 3'to small size paper, and as shown in FIG. In the case of the recording paper center reference feeding method in which the center line with respect to the direction is the same regardless of the recording paper size, either the sensor 13 must be moved according to the recording paper size, or the same number of sensors as the paper size must be provided. I have to.

SUMMARY OF THE INVENTION In view of such drawbacks of the conventional lateral registration mechanism, the present invention is to provide an image forming apparatus having a new lateral registration system having a simple structure, low cost, and high adjustment accuracy. is there.

[Embodiment] FIG. 2 shows an example of a printer embodying the present invention.
Further, FIG. 1 is a top view of the flow of recording paper in the printer of FIG.

The printer 101 in FIG. 2 has the same configuration from the paper feed cassette 2 to the forward / reverse rotation roller 10 as in the printer in FIG. 3, so the description of the movement of the recording paper 3 in that portion will be omitted.

The recording paper 3 which has been switched back by the forward / reverse rotation roller 10 faces the skew feed roller 102. The skew feed roller 102 is a transport roller that is tilted leftward in the traveling direction of the recording paper 3. A lateral registration plate 103 is fixed to the left side of the skew feeding roller 102, and the reference surface 103a of the lateral registration plate 103 is a paper edge of the maximum width recording paper 3'used in the printer 101 as shown in FIG. It is provided to match the position. When the recording paper 3 is sandwiched by the oblique feed rollers 102, the recording paper 3 is conveyed obliquely toward the lateral registration plate 103 as indicated by an arrow A, and the left paper edge 3a is pressed against the reference surface 103a of the lateral registration plate 103. The reference surface 103a is a lateral registration reference when the second image of the printer 101 is recorded, and the recording paper 3 is pressed against the reference surface 103a to perform lateral registration adjustment. After undergoing the lateral registration adjustment, the recording paper 3 is further conveyed by the oblique feed roller 102 along the reference surface 103a, is sent to the registration roller 5, and then receives the second image recording.

Therefore, the recording unit 6 uses the first image as the center reference for the recording paper 3
Then, the second image is recorded on the recording paper 3 on the basis of one side.

The difference between the lateral registration standards when recording the first image and when recording the second image will be described in more detail.

Since the printer 101 feeds the recording paper central reference feeding method, the recording paper 3 is fed from the cassette 2 to the forward / reverse rotation roller 10 as shown in FIG.
Center line C always in the direction perpendicular to the transport direction
It is conveyed so that the (bisector) is the same for all recording paper sizes. Therefore, when the first image is recorded, the recording paper 3
Is recorded at the position 3-1 in FIG. FIG. 3 shows the positional relationship of the recording sheet at the time of recording with respect to the photoconductor 6-1 in the recording section 6, and the recording sheet is at the position 3-1. Next, when the horizontal registration adjustment is performed by the horizontal registration plate 103 and the second image is recorded, the recording paper 3 has the reference surface 103a
Since the paper edge 3a determined in step 3 is sent to the recording unit 6 while maintaining the position where it coincides with the paper edge position of the recording paper 3'having the maximum width, 3-2
Receive a record at the position. This is the same even when the width size of the recording paper is changed, and when receiving the first image recording, the center line C of the recording paper (2 with respect to the direction perpendicular to the traveling direction is always
When the second image is recorded at a position (center reference position) where the bisector line coincides with the center line of the recording paper of another width size, the recording paper is always in a specific order (with respect to its traveling direction). Thus, the image is recorded at a position (one side reference position) where the paper edge on either the left or right side is the same for any size. In other words, when recording the first image, the recording paper is fed by the central reference feeding method, and when recording the second image, the recording paper is fed by the one-sided reference feeding method. On the other hand, in the conventional example of FIG. 4, both the first image recording and the second image recording are performed by the central reference feeding method. In FIG. 3, the first image recording,
The second image recording is also performed at the position 3-1.

When the recording paper is the recording paper 3'having the maximum width, the position of the recording paper when receiving the image recording is 3 in both the first image recording and the second image recording in the present invention and the conventional example.
It is the same as position 3.

[Other Embodiments] In the above description, a laser printer having a double-sided printing function was adopted as an embodiment. However, the present invention is not limited to a recording apparatus having a double-sided printing function, and it is possible to record a plurality of images on the same recording surface. The present invention can be applied to a recording device having a multiple print function for performing the above, or a recording device having both functions.

Further, the recording system is not limited to the electrophotographic system, but can be applied to various recording systems. The type of recording device may be a printer or a copying machine.

If the lateral registration plate 103 is provided on the same side as the lateral reference plane of the sheet feeding cassette 2, the degree of matching between the first image and the second image is high. For example, in the configuration shown in FIG. 1, it is preferable that the horizontal reference surface of the paper feed cassette 2 is on the left side in the feeding direction of the recording paper 3.

Further, it goes without saying that the paper feed cassette 2 may be a paper feed deck or the like capable of stacking a large number of plates.

As described above, in the recording apparatus for recording a plurality of images, when recording the first image, the recording paper is fed by the center reference feeding for recording, and when recording the second image, the recording paper is used as the one side reference. As a result of carrying by feeding and recording, the following effects can be obtained.

1. Regardless of the size of the recording paper, one lateral registration reference can be used to adjust the lateral registration before recording the second image, so no mechanism is required to change the lateral registration reference position according to the size. Becomes

2.Since it is not necessary to change the horizontal resist reference position, the horizontal resist plate can be fixed, and the adjustment error due to the variation of the stop position of the reference position, which cannot be avoided by the mechanism for changing the horizontal resist reference position, is possible. It is possible to eliminate this, and it becomes possible to perform lateral registration adjustment with high accuracy.

3. Paper feeding When feeding from the cassette, the recording paper can be fed by the central reference feed as before, so the feeding method of the central reference feed is simpler than the one-sided reference feed. Can be used as is.

EFFECTS OF THE INVENTION According to the present invention, there is an effect that the configuration for lateral registration adjustment of a sheet (sheet material) is simplified.

[Brief description of drawings]

FIG. 1 is a view of the flow of recording paper in a printer embodying the present invention as seen from above, FIG. 2 is a front view of an example of a printer embodying the present invention, and FIG. 3 is recording paper during image recording. FIG. 4 is a view showing the position of FIG. 4, FIG. 4 is a view of a conventional printer, and FIG. 5 is a view of the flow of recording paper in the conventional printer as viewed from above. 1,101 …… Printer 2 …… Paper feed cassette 3,3 ′, 3-1,3-2,3-3 …… Recording paper 6 …… Recording section 10 …… Forward / reverse roller 102 …… Slant feed roller 103 …… Horizontal resist plate

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akira Hishita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Instructor Haruka Sekiya 3-302 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshifumi Moritani 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuyuki Kubota 340, Kurashizawa-machi, Minamikoma-gun, Yamanashi Japan Precision Industries Co., Ltd. (56) References JP-A-56-122763 (JP, A) JP-A-57-161867 (JP, A) JP-A-62-126062 (JP, A) JP-A-61-101339 (JP, A)

Claims (3)

(57) [Claims] 1. A recording unit capable of recording on a sheet material of a plurality of sizes, wherein after recording a first image on the sheet material in the recording unit, the sheet material is returned to the recording unit again and the sheet is fed. In an image forming apparatus for recording a second image on a material, in order to recirculate the sheet material on which the first image is recorded at the central reference position and record the second image on one side reference position, the sheet material is recirculated during the circulation. A moving unit that moves the sheet material from the central reference transportation position to the one side reference transportation position is provided, and the sheet edge position of the sheet material at the one side reference position for recording the second image is the first edge position. The image forming apparatus is set so as to match the paper edge position of the sheet material having the maximum width when recording the image. 2. The moving means has a lateral registration member having a reference surface for defining the one-side reference position, and a slant for pressing a paper end of a sheet material conveyed on a central reference to the reference surface. A sheet member on which the first image is recorded is pressed against the lateral registration member by the skew feeding member, and then the sheet material is conveyed at one side reference position and the second side at the one side reference position. The image forming apparatus according to claim 1, wherein the image is recorded. 3. A paper feed cassette or paper feed deck in which the one side reference position of the sheet material when recording a second image accommodates the sheet material to be supplied to the recording section for recording the first image. The image forming apparatus according to claim 1 or 2, wherein the horizontal reference plane and the center line of the sheet material are on the same side.