JPH04342247A - Image forming device - Google Patents

Abstract

PURPOSE:To improve the work efficiency by taking data of power error correction of an optical device in an easy operation mode. CONSTITUTION:A document 12 placed on a platen 2 is irradiated with the light from a light source, and the reflected optical image from the document is exposed on a uniformly electrified photosensitive body through the optical device, and an electrostatic latent image formed on the photosensitive body is developed with a developer and is transferred to a transfer material to obtain a copy picture of the document. This image forming device is provided with the optical device having a moving mechanism, which moves a lens barrel 7 in the direction of the optical axis in accordance with the copy magnification, and a moving mechanism which moves it in the direction perpendicular to the optical axis in accordance with each document reference, and the lens barrel 7 can be moved in the direction perpendicular to the optical axis by an extent of movement longer than a maximum placable document width. Scales 33 and 34 are written on the rear face part on the front side or rear face parts on both of front and rear sides of the maximum placable document width reference of the platen 2 in the direction perpendicular to the optical axis.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, and more particularly to an image forming apparatus equipped with an optical device having a function of moving a lens in accordance with a copying magnification or document reference.

0002

2. Description of the Related Art Conventionally, in image forming apparatuses such as copying machines, light from a light source is irradiated onto a document placed on a document table made of contact glass or the like, and the reflected light image from the document is reflected by a mirror or the like. A uniformly charged photoreceptor is exposed to light through an optical system consisting of a lens, etc., and an electrostatic latent image is formed on the photoreceptor.
This electrostatic latent image is developed with a developer such as toner and then transferred to a transfer material to obtain a copy of the original.
As such optical devices such as copying machines, there are known ones that have a function in which the lens moves according to the copying magnification and document standard (■ JP-A-62-71979, JP-A-6
2-87950 etc.). Here, ■ relates to an image forming apparatus equipped with a variable magnification optical device, in which the variable magnification lens block is movable in a direction perpendicular to the conveyance direction of the document, and the arrangement of the document image is changed. It has the ability to make copies. In addition, (2) has a function in which the lens moves in a direction perpendicular to the traveling direction of the copying direction, and a margin is provided on the copy by inputting with the pointing pen.

0003

[Problems to be Solved by the Invention] However, in the optical device as described above, which has a function of moving the lens in accordance with the copying magnification or document standard, the position of the lens or mirror may shift, resulting in magnification errors. This may occur. Therefore, the conventional method for correcting lens and mirror positions to correct magnification errors, etc. is to print a scale on the original or place the scale itself on a contact glass, make a copy, and then The positions of lenses and mirrors were corrected to the appropriate positions due to dimensional differences in copies. However, the problem with the above method is that when making adjustments during manufacturing or service, it is necessary to place the manuscript and scale on the contact glass as described above, which is inefficient and does not improve workability. There is a problem. The present invention has been made in view of the above-mentioned circumstances, and in order to solve the above-mentioned problems, it is possible to obtain data for magnification error correction of an optical device in a simple operation mode without requiring a scale or other original document. An object of the present invention is to provide an image forming apparatus that can improve work efficiency.

0004

[Means for Solving the Problem] In order to achieve the above object, the invention according to claim 1 irradiates light from a light source to a document placed on a document table, and optically converts a reflected light image from the document. Image formation involves exposing a uniformly charged photoconductor to light through a device, developing the electrostatic latent image formed on the photoconductor with a developer, and then transferring it to a transfer material to obtain a copy of the original. In the device,
Equipped with an optical device that has a movement mechanism that moves the lens in the optical axis direction corresponding to the copying magnification and a movement mechanism that moves the lens in the optical axis vertical direction corresponding to each document reference, and the lens can be moved larger than the maximum document width. The lens is characterized by being movable in the direction perpendicular to the optical axis. Further, in the invention as claimed in claim 2, in the image forming apparatus as claimed in claim 1, scales are written on the back surface portion in front of the maximum document width reference of the document table or the back surface portions on both front and rear sides with respect to the direction perpendicular to the optical axis. It is characterized by being

[0005]

In the image forming apparatus according to claim 1, the optical device includes a moving mechanism for moving the lens in the direction of the optical axis corresponding to the copying magnification, and a movement mechanism for moving the lens in the direction perpendicular to the optical axis corresponding to each document reference. Since the lens is movable in the direction perpendicular to the optical axis with a movement width larger than the maximum document width, it is possible to read the image of the portion of the document table outside the maximum document width. Therefore, as described in claim 2, if scales are written on the back surface in front of the maximum document width reference of the document table or on the back surface on both front and rear sides of the document table in the direction perpendicular to the optical axis, the lens can be placed at the maximum position. By moving to the front or rear side of the document width reference, exposing the image of the scale mentioned above to take a copy image, and comparing this copy image with the original scale, magnification error data of the optical device can be easily obtained. Can be done.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on the illustrated embodiments. FIG. 1A shows a schematic configuration of an optical device portion of a copying machine as an example of an image forming apparatus to which the present invention is applied. In FIG. 1(a), 1 is a light source, 2 is a contact glass (original table), 3 is a slit, 4 is a first mirror, and 5 is a light source.
is the second mirror, 6 is the third mirror, 7 is the lens barrel, 8 is the fourth mirror, 9 is the fifth mirror, 10 is the sixth mirror, 11
1 is a photosensitive drum, 12 is a document, 13 is an optical frame, 1
Reference numeral 4 denotes a guide rod that serves as a guide when moving the lens barrel in the optical axis direction (referred to as the X direction). Although not shown, devices necessary for image formation using the well-known electrophotographic method, such as a charging device, a document device, a transfer device, a fixing device, a cleaning device, and a static eliminator, are arranged around the photosensitive drum 11. ing.

In general, a copying machine having variable magnification functions such as enlargement, equal magnification, and reduction, takes a slit scanning type copying machine as an example, as shown in FIG. The reflected light image of the original 12 on the glass 2 passes through the slit 3, the first mirror 4, the second mirror 5, the third mirror 6, and the lens barrel 7 to the fourth mirror 8, the fifth mirror 9, and the sixth mirror. 10 and exposed onto the photoreceptor drum 11. Here, the moving position of the lens barrel during zooming is shown in FIG. 4, but the position of the lens barrel 7 is different between the pressure plate and the ADF (automatic document feeder), as shown in FIG. For example, when the reference of the transfer paper is at the center, when the original reference is in ADF mode, the original is A3 size, and the original is at the same magnification, the lens barrel is at position 7 in FIG. 3. Further, even at the same magnification, if the document reference is the pressure plate mode and the document is B6 size, the lens moves in a direction perpendicular to the optical axis and becomes the position 7a in FIG. 3. Also, in the case of enlargement or reduction, the conjugate length becomes longer than the same size,
The lens is positioned on the document P side when enlarging, and on the photosensitive drum Q side when reducing, depending on the document reference and document size as shown in Figure 3.
and move to the position shown in Table 1.

[0008]

[Table 1]

Next, in order to meet these various demands, a lens moving mechanism in a variable magnification copying machine, that is, a moving mechanism that moves the lens in the optical axis direction corresponding to the copying magnification, and a moving mechanism that corresponds to each document standard are developed. A moving mechanism for moving the optical axis in the direction perpendicular to the optical axis will be explained with reference to FIG. 1(b). still,
Here, the direction of the optical axis of the lens is expressed as the X direction, and the direction perpendicular to the optical axis is expressed as the Y direction. In FIG. 1(b), the lens barrel 7 is fixed by a lens barrel fixing plate 16 on a variable power base 18 for moving in the Y direction, and this variable power base 18 for moving in the Y direction is used as a guide for moving in the Y direction. It is slidably guided by rods 29 and 30. The mechanism for moving in the Y direction includes a drive pulley 25 fixed to the rotating shaft of a drive motor 24 for moving in the Y direction, which is composed of a stepping motor or the like, arranged at one end of the guide rod 29, and a drive pulley 25 fixed at the other end of the guide rod 29. Both ends of a wire 26 stretched between the disposed driven pulley 27 and the driven pulley 27 are connected via springs 28 to both side edges of the variable power base 18 for moving in the Y direction.
5, the wire 26 is rotated between both pulleys to move the variable power base 18 for moving in the Y direction in the direction perpendicular to the optical axis (arrow B in the figure), thereby moving the lens barrel 7. There is.

Each of the components for movement in the Y direction is placed on a variable power base 17 for movement in the X direction, and one side of the variable power base 17 for movement in the X direction slides on a guide rod (X) 14. The other side is supported by the guide rail 15 via a shaft 31 and rollers 32, and is guided movably in the optical axis direction. The mechanism for moving in the X direction includes a drive pulley 20 fixed to the rotating shaft of a drive motor 19 for moving in the X direction, which is composed of a stepping motor or the like, arranged at one end of the guide rod 14, and a drive pulley 20 fixed to the rotating shaft of the drive motor 19, which is made of a stepping motor or the like, arranged at one end of the guide rod 14. Wire 2 stretched between the arranged driven pulley 22
Both ends of the drive pulley 20 are connected via springs 23 to both side edges of the variable power base 17 for moving in the X direction.
The wire 21 is rotated between both pulleys by the rotation of
The variable power base 17 for directional movement is moved in the optical axis direction (arrow A in the figure). In the above-mentioned moving mechanism, the lens barrel 7 is moved with a moving width larger than the maximum document width.
is provided so as to be movable in the direction perpendicular to the optical axis.

Next, FIG. 2 is a view showing an embodiment of claim 2, and FIG. 2(a) is a view of the optical device portion of FIG. 2(b) and 2(c) are views when FIG. 2(a) is viewed from the C direction and the D direction, respectively. As shown in FIG. 2, a scale as a scale reference (front) 33 is marked on the back surface of the contact glass (original platen) 2 on the front side of the maximum document width reference with respect to the direction perpendicular to the optical axis. In addition, there is a scale standard (rear) on the back side.
34 is marked on the scale. It should be noted that these scale standards 33 and 34 are written at front and rear positions outside of the maximum placement document width standard with respect to the direction perpendicular to the optical axis, so that they do not have any influence during normal copying.

Now, the operation section 3 of the control system as shown in FIG.
7 activates the above-mentioned moving mechanism, moves the lens barrel 7 to the position 7g in FIG. 3, copies the image of the scale reference (front) 33 in FIG. 2 at the same size on the transfer paper, As shown in FIG. 2C, the magnification error can be read by abutting the scale reference image copied on the transfer paper 35 against the scale reference (front) 33 and reading the difference in scale. Therefore, in order to correct the magnification error, the position of the lens barrel 7 is moved in the optical axis direction by the amount of correction by the moving mechanism to adjust it to an appropriate position. Also, the magnification error on the rear side can be used in the same way, by moving the lens barrel 7 to the position 7h in FIG.
By copying the image of the scale reference (rear) 34 in FIG. 2 on a transfer paper at the same magnification and reading the difference in scale in the same way as the front side, the magnification error can be read, and the position of the lens barrel 7 can be corrected in the same way. It can be performed. The drive control during the above correction is as follows:
This can be easily performed by the CPU 36 shown in the block diagram of FIG. That is, data on the corrected movement amount for the difference in scale is stored in advance in the CPU memory, and when the difference in scale is entered by key input, the movement motors 19 and 24 are automatically controlled to drive the lens mirror. It is sufficient if the cylinder position is corrected. This makes it possible to collect and correct data on magnification errors of the optical device with simple operations, increasing work efficiency.

[0013]

As described above, in the image forming apparatus according to claim 1, the optical device includes a moving mechanism that moves the lens in the optical axis direction corresponding to the copying magnification, and a moving mechanism that moves the lens in the optical axis direction corresponding to the copying magnification. The lens has a movement mechanism that moves in the direction perpendicular to the optical axis, and the lens can be moved in the direction perpendicular to the optical axis with a movement width larger than the maximum document width to be placed. The image of the part can be read. Therefore, in the image forming apparatus according to claim 2, since the scale is marked on the back surface in front of the maximum document width reference on the document table or the back surface on both front and rear sides with respect to the direction perpendicular to the optical axis, the lens can be adjusted to the maximum width. The magnification error data of the optical device can be easily obtained by moving the placed document to the front or rear side of the width standard, exposing the image on the scale mentioned above, taking a copy image, and comparing this copy image with the scale on the document table. can be taken to. This makes it possible to collect and correct data on magnification errors of optical devices with simple operations, improving work efficiency during manufacturing and service adjustments.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the invention as claimed in claim 1, in which (a) is a schematic configuration diagram of an optical device portion of a copying machine to which the present invention is applied, and (b) is a diagram showing the same optical device as described above. It is a schematic block diagram of the lens movement mechanism of an apparatus.

2 is a diagram showing an embodiment of the invention as claimed in claim 2, in which (a) is a cross-sectional view of the optical device portion of FIG. 2 when viewed from direction E, and (b) (c) is (a) figure C
FIG.

FIG. 3 is an explanatory diagram of the lens barrel movement position according to magnification change and document size of the copying machine shown in FIG. 1;

FIG. 4 is a block diagram showing a schematic configuration of a control system of the copying machine shown in FIG. 1;

[Explanation of symbols]

1... Light source 2... Contact glass (original table) 3... Slits 4, 5, 6, 8, 9, 10... Mirror 7... Lens barrel 11... Photosensitive drum 12 ...Original 14...Guide rod 15 for moving in the optical axis direction...Guide rail 16 for moving in the optical axis direction...Lens barrel fixing plate 17...Magnification variable base 18 for moving in the optical axis direction... - Variable power base 19 for moving in the vertical direction of the optical axis... Drive motor 20 for moving in the optical axis direction... Drive pulley 21 for moving in the optical axis direction... Wire 22 for moving in the optical axis direction... Movement in the optical axis direction Driven pulley 24... Drive motor for moving the optical axis in the vertical direction 25... Drive pulley for moving the optical axis in the vertical direction 26... Wire 27 for moving the optical axis in the vertical direction... Driven pulley for moving the optical axis in the vertical direction 29,30
...Guide rods 33, 34 for moving the optical axis in the vertical direction...
・Scale reference (graduation) 35...Transfer paper 36...CPU 37...Operation unit

Claims (2)

[Claims] Claim 1: A document placed on a document table is irradiated with light from a light source, and a reflected light image from the document is exposed onto a uniformly charged photoreceptor through an optical device. A moving mechanism that moves a lens in the optical axis direction in accordance with the copying magnification in an image forming apparatus that develops an electrostatic latent image formed on the top with a developer and then transfers it to a transfer material to obtain a copy of the original. and a moving mechanism that moves the lens in the direction perpendicular to the optical axis in accordance with each document standard, and the lens can be moved in the direction perpendicular to the optical axis with a movement width larger than the maximum document width to be placed. Features of the image forming device. 2. The image forming apparatus according to claim 1, wherein scales are marked on the back surface in front of the maximum document width reference of the document table or on the back surface on both front and rear sides with respect to the direction perpendicular to the optical axis. Features of the image forming device.