JP3862329B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a printer provided with a document feeder, and more particularly to an image forming apparatus that performs digital image processing.
[0002]
[Prior art]
Conventionally, as a document reading method using an automatic document feeder in an image forming apparatus such as a copying machine or a printer, a document fixing type reading method using an automatic document feeder as shown in FIG. 4 and FIG. There is a document moving type reading method using such an automatic document feeder.
[0003]
In the configuration of FIG. 4, the document S set on the tray 9 is sent to the separation unit 12 by the transport rollers 4 and 5 and separated one by one, and the document glass on the platen glass 7 by the transport roller pair 16 and the transport belt 13. It is sent to a predetermined position and stops. Then, the mirror table 8 holding the light source moves in the direction of arrow A, whereby the document image is read.
[0004]
In the configuration of FIG. 5, the document S set on the tray 9 is sent to the separation unit 12 by the transport rollers 4 and 5, separated one by one, and sent to the document reading unit by the transport roller pair 16. On the other hand, the mirror table 8 holding the light source is fixed at the document reading position, and the document image is read when the document passes through the reading unit.
[0005]
As a method for positioning the automatic document feeder 2 with respect to the image forming apparatus main body 1, a method of inserting a hinge foot of the document feeder 2 into a mounting hole provided on the main body 1 is generally used. In addition to positioning the automatic document feeder 2 on the main body 1, the hinge feet support the weight of the document feeder 2 and the load when the document feeder 2 is opened and closed. The
[0006]
[Problems to be solved by the invention]
The conventional image forming apparatus is configured as described above. With respect to the positional accuracy of the document feeder and the image forming apparatus main body, the document feeding direction of the document fixing type document feeder as shown in FIG. Since the deviation of the perpendicularity of the image reading portion appears as a bend of the entire image, it is not so noticeable with a normal document manuscript or the like. However, in a manuscript feeding type manuscript feeding device, as shown in FIG. Since the misalignment of the angle causes distortion of the image, high accuracy is required.
[0007]
Therefore, in the conventional attachment method, position adjustment after installation is indispensable in order to obtain a perpendicularity between the document feeding direction of the automatic document feeder and the image reading unit of the image forming apparatus main body. That is, the parallel accuracy between the document conveying direction (X direction) and the two hinge feet (L) in the document feeder shown in FIG. 1, the fitting accuracy between the hinge feet and the mounting holes (M) of the body, This is because the perpendicularity deviation between the original and the image reading unit becomes large due to the right angle accuracy between the two mounting holes and the image reading unit (Y).
[0008]
Of these, the positions of X and L and M and Y can be adjusted in advance inside the document feeder and the main body, respectively. It is also a part that receives a large load every time the device is opened and closed, and there is a great risk of misadjustment.
[0009]
And if the position accuracy goes wrong for some reason, it is necessary to make a major readjustment such as adjusting the angle of the whole document feeder by adjusting the mounting position of the hinge foot. There were problems such as having to stop.
[0010]
In addition, since the accuracy of fitting between the hinge foot and the mounting hole also affects the squareness, it is necessary to readjust when the document feeder is replaced due to a failure or the like.
[0011]
The present invention has been made paying attention to the above-mentioned problems, and it is not necessary to take the accuracy and strength of the hinge legs of the document feeder and the mounting holes of the image forming apparatus body more than necessary. An object of the present invention is to provide an image forming apparatus that can achieve weight reduction and cost reduction, increase the stability of the apparatus, and obtain a good image.
[0012]
[Means for Solving the Problems]
The image forming apparatus according to the present invention is configured as follows.
[0013]
(1) In the image forming apparatus including a document feeder, a measuring means for measuring the angular deviation of the mounting position of the original feeding apparatus with respect to the image forming apparatus main body, the image of the document fed by the document feeder Correction means for correcting the position by an amount corresponding to the angular deviation of the mounting position measured by the measuring means, and forming the image in the original feeding direction provided in the original feeding device. An image forming apparatus that measures an angular deviation of the mounting position from a reference base line.
(2) The image forming apparatus according to (1), wherein the correction unit delays image writing in accordance with an angular deviation of the mounting position measured by the measuring unit.
(3) The image forming apparatus according to (1) or (2), further including a storage unit that stores data of an angular deviation of the mounting position measured by the measuring unit.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view showing a schematic configuration of an image forming apparatus according to the present invention. In the figure, 1 is an image forming apparatus main body, and 2 is an automatic document feeder mounted on the main body 1 via a hinge 3, which is rotatable in the direction of arrow B in the figure.
[0019]
In FIG. 1, reference numeral 6 denotes a baseline serving as a positional deviation measurement reference provided on the frame 2 a of the automatic document feeder 2, 7 is a document table glass, 16 is a pair of conveyance rollers for conveying the document to the document table glass 7, 19. Is a CCD for reading a document image.
[0020]
The above-described image forming apparatus is an apparatus of a reading system shown in FIG. 4 and digitally processes an original image read by the CCD 19 and outputs it from a printer unit. Other configurations are the same as those shown in FIGS.
[0021]
4 and 5, 11 is a cover, 17 and 18 are cassettes containing recording paper, 20 is a polygon scanner, 21 is a laser beam, 22 is a photosensitive drum, 23 is a paper feed roller, and 24 is a fixing device. , 25 is a transfer charger, and 26 is a paper discharge tray.
[0022]
FIG. 2 is a block diagram showing a basic configuration of an image shift correction unit provided in the image forming apparatus. In the figure, 31 is a measuring means for measuring the displacement of the mounting position of the automatic document feeder 2 with respect to the image forming apparatus main body 1, 32 is a memory (storage means) for storing the amount of displacement as digital data, and 33 is from the document. A memory 34 for storing the read image as digital data is for correcting the position by an amount corresponding to the amount of deviation stored in the memory 32 with respect to the image of the document stored in the memory 33 and forming an image. The correction means 35 is a printer for writing an image on recording paper.
[0023]
FIG. 3 is a flowchart showing the flow of misalignment correction processing by the correcting means 34. This process is executed by the CPU (not shown) of the control unit of the image forming apparatus main body 1 and is the same method as the so-called italic character conversion process. That is, as shown in FIG. 6A, when the direction (C) of the document image is inclined with respect to the sub-scanning direction of document reading and the dimension (D) is different at both ends, the image is accordingly increased. Is to delay writing.
[0024]
First, the positional deviation is detected by the measuring means 31 (S1) and stored in the memory 32 (S2). Then, the read image of the original is stored in the memory 33 (S3), and the image is formed by the correction means 34 so as to delay the writing in accordance with the misregistration amount stored in the memory 32 (S4). Write.
[0025]
Next, the operation of the above-described embodiment will be described in detail.
[0026]
In recent years, digital technology has become popular in copying machines and the like, and a method of digitally processing an image read by an imaging device such as a CCD and outputting it from a printer unit is becoming mainstream. The above-mentioned conventional problems are solved by utilizing the features of the technology. That is, the positional deviation of the automatic document feeder 2 with respect to the image forming apparatus main body 1 (the deviation of the perpendicularity between the original feeding direction of the automatic document feeder 2 and the image reading unit of the image forming apparatus main body 1) is read. By storing it, the deviation can be corrected at the time of writing.
[0027]
First, the document is set on the tray 9 of the automatic document feeder 2 shown in FIG. 4 and conveyed one by one on the document table glass 7 by the conveyance rollers 4 and 5. The image forming apparatus main body 1 is roughly divided into a reader unit and a printer unit, and a document image reading operation is performed by the reader unit and an image writing operation is performed by the printer unit.
[0028]
In the reader unit, a mirror table 8 composed of a number of mirrors stands by at the lower part of the document table glass 7, takes in the image of the conveyed document, and sends it to the CCD 19. The image signal from the CCD 19 is subjected to digital image processing by an image processing unit configured on a substrate (not shown), and the signal is sent to the polygon scanner 20 in the printer unit. As a result, laser light 21 is emitted from the polygon scanner 20, and a necessary image is formed by the image forming unit including the photosensitive drum 22.
[0029]
On the other hand, transfer paper (recording paper) is loaded on the cassettes 17 and 18 and is conveyed onto the photosensitive drum 22 and the transfer charger 25 by a paper feed roller 23 and the like. Then, the image formed as described above is transferred and discharged onto the discharge tray 26 through the fixing device 24.
[0030]
In this embodiment, as described above, the frame 2a on the side of the platen glass 7 of the automatic document feeder 2 is provided with the base line 6 having a color different from the round color (for example, the frame). Color → White vs. Baseline → Black). The base line 6 may be either a separate member or the same member as the frame, but is adjusted or set with parts accuracy so as to be parallel to the conveying roller (registration roller) pair 16 of the automatic document feeder 2.
[0031]
When the automatic document feeder 2 is attached to the image forming apparatus main body 1, the mirror base 8 looks at the base line 6, reads the positional deviation between the base line 6 and the image reading unit, and calculates the deviation amount. Is stored in the internal memory 32. This positional deviation is a positional accuracy deviation between the document feeder 2 and the image forming apparatus main body 1, that is, the distortion of the image described above. The polygon scanner 20 can write an image on the photosensitive drum 22 in a corrected form.
[0032]
By doing in this way, generation | occurrence | production of distortion etc. of an image can be prevented and a favorable image is obtained. Further, it is not necessary to adjust the position of the image forming apparatus main body 1 and the document feeder 2. Further, by adjusting the positional deviation again by looking at the base line 6 as necessary, even if the position comes for some reason during use, it can be easily solved by rewriting the contents of the memory 32.
[0033]
In the above-described embodiment, the base line 6 is provided on the document feeder 2 and the positional deviation is measured. However, without providing such a baseline or the like, the alignment of the transport roller of the document feeder 2, that is, the image reading unit You may make it measure a position shift by reading a squareness.
[0034]
For example, a window is opened at a corresponding portion of the transport roller pair 16, and the diameter, straightness, etc. of the transport roller pair 16 are sufficiently set with parts accuracy. Then, the mirror 8 looks at the conveyance roller pair 16 and checks the positional deviation between the conveyance roller pair 16 and the image forming apparatus main body 1.
[0035]
In this way, in the previous embodiment, it was necessary to suppress the positional accuracy of the conveying roller pair 16 and the base line 6, but it is only necessary to suppress the positional accuracy of the conveying roller pair 16 alone. In addition, the management will be further improved.
[0036]
As another embodiment, the document feeding direction itself of the document feeder 2 may be checked. For example, a master paper having a sufficient squareness of the paper is prepared, and a service person possesses the master paper so that the master paper can be conveyed when the document feeder 2 is installed, and the perpendicularity with the image reading unit can be adjusted. Check the gap.
[0037]
As described above, in the image forming apparatus that makes use of the features of the digital technology, the positional accuracy deviation between the automatic document feeder 2 and the image forming apparatus main body 1, specifically, the deviation between the original feeding direction and the perpendicularity of the image reading unit. The following advantages can be obtained by performing the image writing operation in a form in which the check is performed by the method described so far and the deviation is corrected.
[0038]
(1) Since the accuracy and strength of the hinge legs of the document feeder 2 and the mounting holes of the image forming apparatus main body 1 need not be required more than necessary, the weight of the apparatus itself is reduced and the cost is reduced.
[0039]
(2) Since there is no need to adjust the mounting portion in terms of product assembly or service, the stability of the apparatus is increased.
[0040]
(3) A good image can be provided with a simple configuration.
[0041]
【The invention's effect】
As described above, according to the present invention, the accuracy and strength of the hinge legs of the document feeder and the mounting holes of the image forming apparatus main body need not be taken more than necessary, and the weight and cost of the apparatus can be reduced. And the stability of the apparatus is increased, and an excellent image can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing a configuration of a deviation correction unit of the apparatus shown in FIG. 1. FIG. 3 is a flowchart showing a flow of misalignment correction processing. 4] A cross-sectional view showing a configuration of an image forming apparatus provided with a document feeding device. [Fig. 5] A cross-sectional view showing a configuration of an image forming device provided with a document feeding device. [Fig. Explanation】
DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Automatic document feeder 3 Hinge 4 Conveying roller 5 Conveying roller 6 Base line 7 Manuscript table glass 8 Mirror table 9 Tray 16 Conveying roller pair 19 CCD
22 Photosensitive drum

Claims (3)

In the image forming apparatus including a document feeder, a measuring means for measuring the angular deviation of the mounting position of the original feeding apparatus with respect to the image forming apparatus main body, the measurement for the image of the document fed by the document feeder Correction means for correcting the position corresponding to the angular deviation of the mounting position measured by the means to form an image , and the measurement means serves as a reference for the document feeding direction provided in the document feeding device. An image forming apparatus that measures an angular deviation of the mounting position from a base line . Wherein the correction means, according to claim 1 Symbol placing the image forming apparatus is characterized in that go delaying the writing of an image in accordance with the angular deviation of the mounting position measured by said measuring means. The image forming apparatus according to claim 1 or 2, characterized in that it has a storage means for storing data of angular displacement of the mounting position measured by said measuring means.

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