JP2000184134A - Image recorder, image reader, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture recorder, a picture reader, and an image forming device where no deviations are caused between image positions of first and second faces and between an original image and a printing image even in the case of the variance in length or feed speed of forms. SOLUTION: The image recorder which can record images on both faces of a recording member 01 is provided with a measuring means 02 which measures the length of the recording member 01 at the time of carrying, a magnification operation means 03 which calculates the magnification of an image to be recorded in accordance with the length of the recording member 01 measured by the measuring means 02 and the length of image information to be recorded on the recording member 01, and an image forming operation control means 04 which forms an image with the magnification according wt the operation result of the magnification operation means 03, and the length of the recording member 01 is measured before an image is formed on the first face of the recording member 01, and image formation magnifications on first and second faces of the recording member 01 are controlled based on the measurement result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus such as a printer capable of printing on both sides of a recording sheet, an image reading apparatus such as an image scanner capable of reading images on both sides of a document, and further, to both sides of a transfer sheet. The present invention relates to an image forming apparatus such as an electrophotographic copying machine capable of forming an image on a front side, and more particularly, to a method for correcting the image position on the front side and the back side during double-side reading or double-side printing.

[0002]

2. Description of the Related Art Conventionally, as an image recording apparatus such as a printer capable of printing on both sides of a recording sheet of this type, an image recorded on the back side of the recording sheet is rotated so that an image recorded on the front side of the recording sheet is rotated. There is a configuration in which the orientation of an image to be recorded on the back side of a sheet is matched (Japanese Patent Laid-Open No. 62-18 / 1987)
1155, JP-A-63-242665, JP-A-6-343125, etc.).

In such an image recording apparatus, for example, when a vertically written image is printed on both sides of a vertically fed sheet at the binding position on the left side, the image on the front side is printed as it is, and the image on the back side is rotated by 180 °. There is a printer that prints on the paper from the rear and aligns the image on the front and back of the paper.

However, in the above-described image recording apparatus, when the paper feed direction and the print image direction are different between the front side and the back side of the recording paper, if the paper length or the paper feed speed varies, FIG. As described above, there is a problem that the image position on the front surface and the image position on the back surface of the recording paper are shifted.

Further, as an image reading apparatus such as an image scanner capable of reading images on both sides of the document, there is an image reading apparatus configured to rotate the read image in accordance with the orientation and the binding position of the image of the document (Japanese Patent Laid-Open Publication No. HEI 9-122572). 8-88861).

In such an image reading apparatus, for example, when reading a sheet which has been printed on both sides at the binding position left on a vertically fed sheet as a vertically fed document, the image on the front side of the document is read as it is, and the image on the back side of the document is read. Is rotated by 180 ° after reading, so that the orientation of the image is matched between the front surface and the back surface.

However, in the above-described image reading apparatus, since the original feeding direction and the direction of the printed image are different between the front side and the rear side of the original, the original length or the original feeding speed may vary. In addition, there is a problem that an image position is shifted between an image obtained by reading the front surface of the document and an image obtained by reading the back surface of the document.

Further, as an image forming apparatus such as an electrophotographic copying machine capable of forming an image on both sides of the transfer sheet, an image to be copied on the back side of the transfer sheet is rotated and copied on the front side of the transfer sheet. There is a configuration in which the positional relationship between an image and an image copied on the back surface of a transfer sheet is matched (Japanese Patent Application Laid-Open Nos. 62-181155 and 63-24).
2665, JP-A-6-343125, etc.).

In such an image forming apparatus, for example, when an image on one side of a document is sequentially read and sequentially printed on both sides of a transfer sheet, the image is rotated by 180 ° when printing on the back side of the transfer sheet. Some are designed to print on paper from the rear (one-sided → two-sided copy).

Further, in such an image forming apparatus, there is also a system in which a double-sided document is sequentially read and sequentially printed on both sides of a transfer sheet (double-sided → double-sided copy).

However, in the above-described image forming apparatus, in the case of single-sided to double-sided copying, the paper feeding direction differs between the front and back sides of the paper and the direction of the image to be printed. In such a case, there is a problem that the image position between the front surface and the back surface is shifted.

Further, in the above image forming apparatus, in the case of double-sided to double-sided copying, since the original feeding direction and the direction of the printed image are different between the front and back sides of the original, the original length or original There is a problem that the image position is shifted between the image obtained by scanning the front surface of the document and the image obtained by scanning the back surface when there is a variation in the feeding speed, and the image to be printed and the paper feeding direction are printed on the front and back surfaces of the paper. Are different from each other, there is a problem that the image position on the front surface and the back surface is shifted when the length of the paper or the paper feeding speed varies.

Therefore, as a technique capable of solving such a problem, there is a technique disclosed in Japanese Patent Application Laid-Open No. 4-85064, for example. The double-sided printer according to Japanese Patent Application Laid-Open No. 4-85064 is a double-sided printer having a margin direction designation means for designating either a longitudinal edge or a lateral side edge of a sheet as a margin. When double-sided printing is performed with the longitudinal edge of the paper specified as a binding margin by the specifying means, the assumed paper size when creating print data in the memory and the size of the paper actually used for printing are determined. A size comparing means for comparing, and a printing position correcting means for correcting a printing position deviation between the front and back sides of the paper at the time of printing when the two sizes are determined to be different by the means are provided. is there.

[0014]

However, the prior art described above has the following problems. That is, in the case of the double-sided printer disclosed in Japanese Patent Application Laid-Open No. 4-85064, when double-sided printing is performed in a state where the side edge in the longitudinal direction of the paper is specified as a binding margin by the binding margin direction designating means, it is not possible to print on the memory. Size comparison means for comparing the assumed paper size when creating print data with the size of the paper actually used for printing; and, when the means determines that the two sizes are different, the surface of the paper at the time of printing And the print position correction means that corrects the print position deviation on the back side, so that the size of the paper actually used for printing is different from the assumed paper size when creating the print data in the memory. Although the printing position can be corrected to some extent by the printing position correction means, there is no variation in the paper size. If the paper speed for transporting the paper for printing varies, or if the paper size varies and the transport speed for transporting the paper for printing varies, It is not possible to correct the printing position to an appropriate position only by the correction based on the size, and there is a problem that the printing position of the image on the front surface and the printing position of the image on the back surface are shifted.

Such a problem occurs not only in a double-sided printer but also in an image reading apparatus that reads images on both sides of a document and an image forming apparatus that forms images on both sides of a transfer sheet.

The inventor of the present invention has solved the above-mentioned problems of the prior art, and has set one of the front surface and the back surface to 180 degrees.
When forming an image on the first surface of the recording member when performing double-sided printing by rotating the recording member, the length of the recording member is measured, and the image forming position on the second surface is controlled based on the measurement result. As a result, an image recording apparatus, an image reading apparatus, and an image forming apparatus that do not cause a shift in the image position between the first surface and the second surface even when the length of the sheet or the sheet feeding speed varies are already proposed. (Japanese Patent Application No. 9-180)
079).

More specifically, the image recording apparatus described above comprises:
In an image recording apparatus capable of recording an image on both sides of a recording member, the image recording apparatus includes a measuring unit that measures a length of the recording member during conveyance, and an image position control unit that controls a position of an image recorded on the recording member. The length of the recording member is measured when an image is formed on the first surface of the recording member, and the image forming position on the second surface is controlled based on the measurement result.

However, in the case of the image recording apparatus or the like proposed by the present inventor, the image forming position on the second surface is controlled based on the measurement result of the length of the recording member, so that the leading edge of the image is controlled. The portion coincides with the leading edge of the recording paper on both the first surface and the second surface, and the trailing edge of the image also coincides with the first and second surfaces, but the trailing edge of the image is There is a problem that the original image and the registration position, particularly the rear end registration, are shifted from the rear end of the recording sheet by the amount of controlling the formation position.

FIG. 24 shows front and back original images and recording paper. In this example, the recording paper is larger than the original image. FIG. 25 shows the front and back images when the image on the front surface is recorded as it is on a recording sheet and the image on the back surface is rotated by 180 degrees, and in this case, Japanese Patent Application No. Hei 9-180079. As described in the related art of the patent application, the positions of the front and rear images are shifted. FIG. 26 shows that the inventor of the present invention disclosed in Japanese Patent Application No. Hei.
In the method proposed in the patent application No. 79, the image on the front side is kept as it is, and the image on the back side is rotated by 180 degrees and when the formation position of the image is controlled, the front and back images recorded on the recording paper are changed. It is shown.

In the case of FIG. 24, the positions of the front and back images are not shifted, but the registration at the rear end (the lower part in the image direction) of the image is shifted upward with respect to the original image. There is a blank space at the rear end of the front and back images.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to solve the problem of the first surface even when the paper length or paper feeding speed varies. It is an object of the present invention to provide an image recording apparatus, an image reading apparatus, and an image forming apparatus in which there is no shift between the image position on the second surface and the original image and the printed image.

[0022]

That is, according to the first aspect of the present invention, there is provided an image recording apparatus capable of recording an image on both sides of a recording member as shown in FIG.
Measuring unit 02 that measures the length of the recording member 01 during transport, and the length of the recording member 01 measured by the measuring unit 02 and the length of image information to be recorded on the recording member 01,
Magnification calculating means 03 for calculating a magnification of an image to be recorded;
An image forming operation control unit for forming an image at a magnification corresponding to the calculation result of the magnification calculating unit, wherein the length of the recording member is measured before an image is formed on the first surface of the recording member. The image forming magnification of the first surface and the second surface of the recording member 01 is controlled based on the measurement result.

The invention according to claim 2 is the image recording apparatus according to claim 1, wherein an image is formed by rotating an image on the second surface of the recording member.

Further, the invention according to claim 3 is an image recording apparatus according to claim 1 or 2, further comprising a mode selection means capable of selecting whether or not to change the image forming magnification. .

Still further, the invention described in claim 4 is as follows.
4. The image recording apparatus according to claim 1, wherein when a calculation result of said magnification calculation means exceeds a predetermined value, a change in magnification of the image forming operation control means is prohibited. .

According to a fifth aspect of the present invention, there is provided an image reading apparatus capable of reading images on both sides of a document, a first measuring means for measuring a length of the document when the document is transported, and reading the document. A second measuring means for measuring the length of the image to be read, and an image to be read from the length of the document measured by the first measuring means and the length of the document image measured by the second measuring means. A magnification calculating means for calculating the magnification of the original, and an image reading operation control means for outputting an image read at a magnification according to the calculation result of the magnification calculating means. Is measured, and the image reading magnification of the first and second surfaces of the document is controlled based on the measurement result.

According to a sixth aspect of the present invention, there is provided an image forming apparatus capable of forming an image of an original on both sides of a transfer member, wherein the first measuring means for measuring the length of the original when the original is transported; A second measuring unit for measuring the length of the member when the member is conveyed; and a length of the document measured by the first measuring unit and a length of the transfer member measured by the second measuring unit. Magnification calculating means for calculating the magnification of the power image, and image forming operation control means for forming an image at a magnification corresponding to the calculation result of the magnification calculating means. The length of the transfer member is measured before an image is formed on the first surface of the member, and the image forming magnification of the first and second surfaces of the transfer member is controlled based on the measurement results. Things.

[0028]

According to the first aspect of the present invention, there is provided a measuring means for measuring a length of the recording member during conveyance, a length of the recording member measured by the measuring means, and an image to be recorded on the recording member. A magnification calculating unit configured to calculate a magnification of an image to be recorded based on the length of the information; and an image forming operation control unit configured to form an image at a magnification corresponding to a calculation result of the magnification calculating unit. Since the length of the recording member is measured before an image is formed on one surface, and the image forming magnification of the first and second surfaces of the recording member is controlled based on the measurement result, the recording member is controlled. By measuring the length of the recording member before forming an image on the first surface of the recording member, and controlling the image formation magnification of the first surface and the second surface of the recording member based on the measurement result, The length or feed speed of the recording material varies. Even if it is possible to first and second surfaces to the image position of never shift occurs in a matter of course, to prevent the deviation occurs between the original image and the printed image.

According to the fifth aspect of the present invention, the first measuring means for measuring the length of the original when the original is transported, and the second measuring means for measuring the length of the image to be read of the original Means, a magnification calculating means for calculating a magnification of an image to be read from a length of the document measured by the first measuring means and a length of the image of the document measured by the second measuring means; Image reading operation control means for outputting an image read at a magnification corresponding to the calculation result of the calculation means, and measuring the length of the document before reading the image on the first side of the document; Since the image reading magnification of the first and second sides of the original is controlled based on the original, the length of the original is measured before reading the image of the first side of the original, and based on the measurement result, Image reading magnification of the first and second sides of the original By controlling the, the feed rate of the length or the original of the document, even if there are variations,
It is possible to prevent a shift between the original image and the read image, as well as to prevent a shift between the image positions of the first surface and the second surface.

According to the invention described in claim 6,
A first measuring unit for measuring the length of the original during transport, a second measuring unit for measuring the length of the transfer member during transport, and the length of the original measured by the first measuring unit. Magnification calculating means for calculating the magnification of an image to be formed from the length of the transfer member measured by the second measuring means; and image forming operation control for forming an image at a magnification corresponding to the calculation result of the magnification calculating means. Means for measuring the length of the original at the time of reading, and measuring the length of the transfer member before forming an image on the first surface of the transfer member,
Based on these measurement results, the first surface and the second surface of the transfer member
Since the image forming magnification of the surface is controlled, the length of the original is measured at the time of reading, and the length of the transfer member is measured before forming an image on the first surface of the transfer member.
Based on these measurement results, the first surface and the second surface of the transfer member
By controlling the image forming magnification of the first surface, even if the length of the original or the feed speed of the original, or the length of the transfer member or the feed speed of the transfer member varies, the image on the first surface and the second surface can be changed. It is possible to prevent a displacement from occurring between the image of the original and the image of the transfer member, as well as to prevent the displacement from occurring.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings.

FIG. 2 is a schematic diagram showing an image recording apparatus using laser xerography according to one embodiment of the present invention.

In FIG. 2, reference numeral 1 denotes a housing of the image recording apparatus.
An image processing device 2 that performs predetermined image processing as necessary on image information read by an image reading device (not shown) that reads an image of a document or an image signal sent from a host computer, a personal computer, or the like; ROS (Rast) that performs image exposure based on image information on which predetermined image processing has been performed by the image processing device 2
An image writing unit 3 composed of an r output scanner or the like is provided, and the image writing unit 3 performs image writing with a laser beam LB according to image information.

The image writing means 3 emits laser light LB from a semiconductor laser (not shown) according to gradation data, and deflects and scans the laser light LB emitted from the semiconductor laser by a rotary polygon mirror.
The scanning exposure is performed on the photosensitive drum 4 via the reflection mirror.

As the photosensitive drum 4 to which the laser beam LB is scanned and exposed by the image writing means 3, for example, a photosensitive body using an organic photoconductive substance is used.
The photosensitive drum 4 is driven to rotate at a predetermined speed in a direction indicated by an arrow by driving means (not shown). The surface of the photosensitive drum 4 is charged to a predetermined potential in advance by a primary charging means such as a charging roll (not shown), and is then subjected to scanning exposure with laser light LB in accordance with image information to form an electrostatic latent image. Is done. The electrostatic latent image formed on the photoconductor drum 4 is developed by a developing roll of a developing device (not shown) to become a toner image.

The toner image formed on the photosensitive drum 4 is transferred onto a recording paper 6 as a recording medium by charging of a transfer roll 5 arranged so as to contact the photosensitive drum 4. The recording paper 6 onto which the toner image has been transferred is discharged from the photosensitive drum 4 by discharge of a separation charger consisting of a needle-like electrode (not shown) and is separated from the photosensitive drum 4. An AC voltage,
Alternatively, an AC voltage on which a DC voltage is superimposed is applied. As shown in FIG. 2, the recording paper 6 is fed by a feed roll 8 from a paper tray 7 arranged at a lower part in the housing 1 of the image forming apparatus. The fed recording paper 6 is conveyed to a registration roll 10 as a registration gate via a paper conveyance path 9 and then temporarily stopped by the registration roll 10 to synchronize with the image on the photosensitive drum 4. To the surface of the photosensitive drum 4. Reference numeral 11 denotes a paper detection sensor that detects the leading and trailing ends of the recording paper 6 provided at the exit of the paper tray 7, and 12 detects the leading and trailing edges of the recording paper 6 provided in front of the registration roll 10. The sheet detection sensors to be used are shown.

As described above, the recording paper 6 on which the toner image has been transferred from the photosensitive drum 4 is discharged by the separation charger composed of the needle-shaped electrodes, and is separated from the surface of the photosensitive drum 4 as described above. Then, the toner image is conveyed to a fixing device 14 via a sheet conveying path 13, and the toner image is fixed on the recording paper 6 by heat and pressure by the fixing device 14. The image is discharged onto the discharge tray 16 by the reversing roll 15, and the image recording process is completed. Reference numeral 17 denotes a sheet detection sensor that detects the leading end and the trailing end of the recording sheet 6 disposed downstream of the fixing device 14.

After the toner image transfer step is completed, the surface of the photosensitive drum 4 is cleaned with a cleaning device (not shown) equipped with a cleaner blade, a brush, and the like to remove residual toner, paper dust, etc. It is prepared for the recording process.

When images are recorded on both sides of the recording sheet, the recording sheet 6 on which the image is recorded on one side is not discharged onto the discharge tray 16 as it is, and the trailing end of the recording sheet 6 is The sheet reversing roll 15 is rotated in the reverse direction while being held between the recording sheets 6 on which an image is recorded on one side.
Is again conveyed to the transfer position of the photosensitive drum 4 in a state where it is turned upside down by the double-sided module 18 attached to the side surface of the image recording apparatus housing 1. The double-sided module 18 includes a plurality of paper transport rolls 20, 21, and 22 arranged along a paper transport path 19, and registers the recording paper 6 on which an image is recorded on one side in a state where the recording paper 6 is turned upside down. It is configured to be conveyed to the registration roll 10 via a paper conveyance roll 23 arranged on the upstream side of the roll 10. Reference numeral 24 denotes a sheet detection sensor that detects the leading and trailing ends of the recording sheet 6 provided in front of the sheet transporting roll 22.

As shown in FIG. 2, the image recording apparatus includes a photosensitive drum 4, a transfer roll 5, a feed roll 8, a registration roll 10, a fixing device 14, a sheet reversing roll 15, and the like, not shown. It is configured to be driven by a drive motor 26 via a drive system including gears and the like.

In this embodiment, the rotation speed of the drive motor 26 is variable, and
By controlling the rotation speed of the drive motor 26, the transport speed of the recording paper 6 can be changed, and the image formation magnification in the transport direction of the recording paper 6 can be changed. Note that the transport speed of the recording paper 6 may be changed by interposing a gear via a clutch (not shown) in the middle of the drive system without directly changing the rotation speed of the drive motor 26. Also, by changing the image writing pitch by the image writing means 3, the image formation magnification in the transport direction of the recording paper 6 may be changed.

The image writing means 3 has an ASIC (Application Specification) provided with a register for controlling the position and length of an image to be written.
icIntegrated Circuit).

FIG. 4 is a diagram showing the relationship between the register of the ASIC and the position and length of the image to be written.

In FIG. 4, SOS (Start Of)
Scan) indicates a writing start reference position at which an image is written on the photosensitive drum 4.
The detection of S is performed by detecting the laser beam LB emitted from the image writing unit 3 by the sensor 25 provided at the SOS position. Also, LSUP
(Line Sync Up Point), LSDP
(Line Sync Down Point) indicates a rising position and a falling position of a line sync (LSYNC) signal in the sub-scanning direction, respectively. Furthermore, ALSUP (Another Line Sync)
Up Point), ALSDP (Another)
Line Sync Down Point is an actual image writing area in consideration of the side offset in the sub-scanning direction, and a PSSP (Page Sync Start).
Point) and PSEP (Page Sync End)
Point) is a page sync (PSYN) in the main scanning direction.
C) Rising and falling edges of the signal, APSSP (An
other Page Sync Start Point
t) and APSEP (Another Page Syn)
c EndPoint) indicates an actual image writing area in consideration of the offset at the front and rear ends in the main scanning direction. The registers for determining APSSP, APSEP, and the like are set according to the sheet size at the start of sheet feeding, and can count the number of lines actually written after writing is started.

FIG. 3 is a block diagram showing the control means of the image recording apparatus constructed as described above.

In FIG. 3, reference numeral 31 denotes a CPU which controls the operation of the image recording apparatus and also functions as magnification calculating means and image recording operation control means; 32, a ROM (read only memory); 33, a RAM (random access memory). , 34 are image rotating means for rotating image information, 37 is a sheet transporting means including a registration roll 10, a transfer roll 5, a fixing device 14, a sheet reversing roll 15, and the like.
Reference numeral 5 denotes control of the image writing means 3, the feed roll 8, the registration roll 10, and the sensors 11, 12, and 1.
These are I / O ports for recognizing input values such as signals from signals 7 and 24 and controlling the time measuring means 36. The image rotation means 34 and the I / O port 35 are controlled by the CPU 31. The image rotating means 34 is composed of a memory for storing images and an ASIC for controlling reading of the stored images. Further, the CPU 31
In the operation panel 38, image recording conditions such as the size of the recording paper 6 and the number of recording sheets can be input through the operation panel 38, and the operation panel 38 determines whether or not to perform the magnification change according to the present embodiment. It has selectable mode selection means.

In the image recording apparatus according to this embodiment having the above-described configuration, as described below, regardless of the size of the paper, there is no variation in the paper transport for printing or reading. Even if there is a variation in the speed, a variation in the size of the paper, or a variation in the size of the paper, and a variation in the transport speed when transporting the paper for printing or reading, the first Face and second
The position of the image on the surface and the deviation between the original image and the printed image are prevented from occurring.

Next, a specific operation will be described with reference to the flowcharts shown in FIGS.

First, when the image recording operation is started in the image recording apparatus, as shown in FIG. 5, the feeding of the recording paper 6 is started (step 11), and the recording paper fed from the paper tray 7 by the feed roll 8 is shown in FIG. Paper 6
Turns on the paper detection sensor 11 (step 1).
2). Then, at the same time as the recording paper 6 turns on the paper detection sensor 11, the CPU 31 starts measuring time by the time measuring means 36, and the recording paper 6 passes through the paper detection sensor 11, and the paper detection sensor 11
Is turned off, the time measurement is ended by the time measuring means 36 (step 13).

Next, the CPU 31 determines whether or not the magnification change is permitted by the mode selection means (not shown) of the operation panel 38 (step 14). Detection sensor 12
Is determined to be ON (step 16).

On the other hand, when the change of the magnification is permitted, the CPU 31 calculates the size of the recording paper 6 based on the passage time of the recording paper 6 measured by the time measuring means 36 and calculates the image recording magnification. (Step 15).
Here, the calculation of the image recording magnification is performed by the length T1 of the recording paper 6 in the sub-scanning direction (paper transport direction) as shown in FIG.
If the length T1 of the recording sheet 6 is larger than the length T2 of the recording image in the sub-scanning direction, the recording magnification (enlargement) is obtained by T1 / T2. As shown in FIG. 10, the image recording magnification is calculated based on the length T3 of the recording paper 6 in the sub-scanning direction (paper transport direction) and the length T4 of the recording image in the sub-scanning direction. If the length T3 is smaller than 6, the recording magnification (reduction) is determined by T3 / T4.
At this time, the size of the image to be recorded is notified in advance from a host computer or the like.

In the above embodiment, the case where only the magnification in the sub-scanning direction of the recording paper is changed, but the magnification in the scanning direction of the recording paper 6 (the direction orthogonal to the paper transport direction) is changed. In this case, the image recording magnification is calculated in the same manner as described above. Further, the magnification in the scanning direction of the recording paper 6 (the direction orthogonal to the paper transport direction) is changed by changing the image writing magnification by the ROS.

Thereafter, the CPU 31 turns on the paper detection sensor 12 for the recording paper 6 and simultaneously sets the time
6, the measurement of time is started (step 16), and it is determined whether or not a predetermined time has elapsed (step 17), and the conveyance of the sheet is stopped after the time when the leading edge of the sheet reaches the registration roll 10 (step 18). . After temporarily stopping the conveyance of the sheet, the CPU 31 waits until an image to be written on the surface of the photosensitive drum 4 is ready (step 19). The image written on the surface of the photosensitive drum 4 is an image read by an image reading device (not shown), an image developed by a host computer, an image received by facsimile, or the like.

When the CPU 31 detects that the image is ready, it determines again whether or not the change of the magnification is permitted, and the magnification calculated as described above is within a predetermined range (for example, ± 3 to 5). %) Is determined (step 20). If the magnification change is not permitted or the calculated magnification is not within the predetermined range, the magnification change is not performed. On the other hand, if the change of the magnification is permitted and the calculated magnification is within the predetermined range, the magnification is changed (step 21).

Here, when changing the image recording magnification, as shown in FIG. 9, when enlarging the image to be recorded on the recording paper 6, the paper of the paper transport means 37 when the registration roll 10 is driven again is used. The conveying speed was set faster than the predetermined speed according to the calculated magnification, and when the image to be recorded on the recording paper 6 was reduced as shown in FIG. 10, the registration roll 10 was driven again. In this case, the sheet conveying speed of the sheet conveying means 37 is set to be lower than a predetermined speed in accordance with the calculated magnification.

Next, the CPU 31 moves the registration roll 10
And the writing by the image writing means 3 is started in synchronization (step 22). This resist roll 10
Is synchronized with the writing by the image writing means 3,
The distance is determined based on the distance between the registration roll 10 and the transfer roll 5, the writing position on the photosensitive drum 4, and the distance between the transfer roll 5. In this embodiment, since the distance between the registration roll 10 and the transfer roll 5 is larger,
After driving the registration roll 10 (step 22), time measurement is started by the time measuring means 36, and it is determined whether or not a certain time has elapsed (step 23). Writing is started (step 24). Then, by driving the registration roll 10, the recording paper 6 is
The sheet is conveyed by the resist roll 10 and reaches the transfer section (step 25). On the other hand, the image written on the photosensitive drum 4 by the image writing means 3 moves to the transfer section by the rotation of the photosensitive drum 4 (Step 25).

Since the driving of the registration roll 10 and the start of image writing are synchronized as described above, the leading edge of the recording paper 6 and the leading edge of the image coincide, and the image is sequentially transferred to the recording paper 6. (Step 26). When the trailing end of the conveyed recording paper 6 passes through the paper detection sensor 12 and turns off the paper detection sensor 12 (step 27),
Time measurement is started by the time measuring means 36, and it is determined whether or not a fixed time has elapsed (step 28). After the fixed time, the writing by the image writing means 3 is terminated (step 29). Make the end coincide with the end of image writing.

Then, the transported recording paper 6 turns on the paper detection sensor 17 (step 30) and reaches the paper reversing roll 15 (step 31). The paper reversing roll 15 is driven so as to convey the recording paper 6 in the direction of the discharge tray 16. When the conveyed recording paper 6 turns off the paper detection sensor 17 (step 32), time measurement is started by the time measuring means 36, and it is determined whether or not a predetermined time has elapsed (step 33). The sheet reversing roll 15 is reversed (step 34),
The recording paper 6 is conveyed in the direction of the duplex module 18.
The recording paper 6 is transported along the paper transport path 19, and turns on the paper detection sensor 24 (step 35). When the paper detection sensor 24 is turned on, the conveyance of the recording paper 6 is stopped.

When the conveyance of the recording paper 6 is temporarily stopped, it waits for the preparation of the image to be written on the back surface (step 3).
6). The image on the back side written by the image writing unit 3 is an image read by an image reading device, an image developed by a host computer, an image received by facsimile, or the like. When the image is ready, the image information of the back side is stored in the image memory in the image rotating means 34.

When the accumulation of the back side image information is completed, FIG.
As shown in (5), the conveyance of the recording paper 6 is started (step 37). The recording paper 6 turns on the paper detection sensor 12 (step 38). Then, the CPU 31 starts time measurement by the time measuring means 36, and determines whether or not a predetermined time has elapsed (step 39). After the time to reach the registration roll 10 has elapsed, the conveyance of the recording paper 6 is stopped (step 40).

FIG. 11 shows the direction of writing an image stored in the page memory and the writing start point.

FIG. 11 shows an example of writing at 180 ° rotation. When the image is not rotated at 180 °, the image is not accumulated, and the image sent from the host computer or the like may be written in the same manner as the front surface. Whether or not to rotate is determined in advance based on the binding position of double-sided printing or the like. The writing start point in the sub-scanning direction is always constant.

To further explain, as shown in FIG.
> T2, that is, when the detected paper length T1 in the sub-scanning direction of the front side printing is larger than the image length T2 in the sub-scanning direction, the length of the recording paper 6 is a predetermined length. When the image is recorded on the rear surface of the recording paper 6 at a predetermined distance from the rear end, the conveyance speed of the recording paper 6 is slower than a predetermined speed.
As shown in FIG. 12, the image is recorded on the back surface of the recording paper 6 with the rear end of the image shifted upward. for that reason,
In the case of T1> T2, as shown in FIG. 9, the recording magnification of the image is enlarged to T1 / T2, and the recording of the image is started from a predetermined writing start point, so that the front and rear surfaces of the recording paper 6 are formed. The image can be aligned with high accuracy, and the rear end of the recorded image on both the front and back sides is formed on the recording paper 6.
Can be accurately matched with the rear end, and it is possible to prevent the occurrence of a shift between the image position on the front surface and the back surface and between the original image and the printed image.

As shown in FIG. 10, when T3 <T4, that is, when the length T of the detected recording paper 6 in the sub-scanning direction is
3 is smaller than the length T4 of the recording image in the sub-scanning direction, the length of the recording paper 6 is shorter than the predetermined length, or the transport speed of the recording paper 6 is lower than the predetermined speed. If the image is recorded on the rear surface of the recording paper 6 as it is at a predetermined distance from the rear end, the image is recorded on the rear surface of the recording paper 6 so as to be shifted upward from a predetermined position. Will be. Therefore, when T3 <T4,
As shown in FIG. 10, by reducing the recording magnification of the image to T3 / T4 and starting recording the image from a predetermined writing start point, the image on the front surface and the rear surface of the recording paper 6 can be accurately aligned. And the rear end of the recorded image on both the front and back sides can be accurately matched with the rear end of the recording paper 6, so that the image positions of the front and back sides and the deviation between the original image and the printed image can be prevented. Can be prevented.

Further, when T1 = T2, that is, when the detected length T1 of the recording paper 6 in the sub-scanning direction is equal to the length T2 of the recording image in the sub-scanning direction, the length of the recording paper 6 is Is equal to a predetermined length, and the conveyance speed of the recording paper 6 is equal to the predetermined speed. If an image is recorded on the back surface of the recording paper 6 as it is, as shown in FIG. The front and back images can be accurately aligned, and the rear end of the recorded image can be accurately matched with the rear end of the recording paper 6 on both the front and back surfaces. It is possible to prevent a shift between the image and the printed image.

When the image on the back side is thus prepared, the registration roll 10 is driven to start the conveyance of the recording paper 6 (step 41), and the writing is started in the same manner as for the front side printing (step 41). 42-44). Since the driving of the registration roll 10 and the start of writing are synchronized, the leading edge of the recording paper 6 coincides with the leading edge of the image, and the image is sequentially transferred to the recording paper 6 (step 45). When the conveyed recording paper 6 turns off the paper detection sensor 12 (step 46), the image writing is terminated after a certain period of time, and the end of the image is coincident with the end of the image writing (steps 47 and 48). The transported recording paper 6 turns on the paper detection sensor 17 and reaches the paper reversing roll 15 (step 49). The paper reversing roll 15 is driven to convey the recording paper 6 in the direction of the discharge tray 16, and discharges the recording paper 6 onto the discharge tray 16 (Step 50).

As described above, even when the length or paper feed speed of the paper varies, the image recording apparatus which does not cause a shift between the image position of the front and back surfaces of the recording paper 6 and the original image and the printed image. Can be provided.

Embodiment 2 FIG. 14 is a schematic configuration diagram showing an image reading apparatus according to Embodiment 2 of the present invention.

The image reading apparatus includes an automatic document feeder 40 as shown in FIG. The automatic document feeder 40 has a document tray 42 on which a plurality of documents 41 to be copied are set with the copy surface facing upward, and the plurality of documents 41 set on the document tray 42.
Is the uppermost original 41 by the original feed roll 43.
Are sequentially picked up and sent to the original transport rolls 45 and 46 along the original transport path 44. A document detection sensor 55 that detects the leading and trailing ends of the document 41 is disposed downstream of the document feed roll 43. A document detection sensor 47 for detecting the leading edge and the trailing edge of the document 41 is provided between the document transport rollers 45 and 46.
Is arranged. Then, the original 41 is separated one by one by the original feed roll 43 as described above, and is sent to the image reading unit 48 by the plural original transport rolls 45 and 46 provided along the original transport path 44. Is conveyed. While the document 41 conveyed to the image reading unit 48 is conveyed at a constant speed by a document conveying roll 49 arranged downstream of the image reading unit 48,
The image is read by an image reading element such as a CCD via a scanning optical system of the image reading apparatus stopped at a reading position (not shown). Although not shown, the scanning optical system includes an illumination lamp for illuminating the original 41, a full-rate mirror for reflecting a light image of the original illuminated by the illumination lamp, and a light image from the full-rate mirror to be folded. It comprises two reflecting half-rate mirrors, and an imaging lens that forms an optical image of a document reflected by these half-rate mirrors on an image reading element in a reduced state.

When reading the image of the document 41 moving at a constant speed on the image reading section 48 by the image reading device, the image of the document 41 is read with the scanning optical system (not shown) stopped. It has become. When reading the image of the document 41 placed on the platen glass 50 by the image reading device, an illumination lamp (not shown) and a full-rate mirror and a half-rate mirror move along the lower surface of the document 41 along the lower surface of the document 41. The image on the document 41 is read by scanning at a speed ratio of 1/2.

Thereafter, the document 41 read by the image reading section 48 is discharged onto a document discharge tray 52 by a document reversing roll 51. Reference numeral 53 denotes a document detection sensor that detects the leading edge and the trailing edge of the document 41.

When the two-sided reading of the original is performed by the image reading apparatus, the original 41 on which one side of the image has been read is transferred by the original reversing roll 51 to the original discharge tray 5.
The document reversing roll 51 is temporarily stopped while the rear end of the document 41 is being nipped by the document reversing roll 51 without being directly discharged onto the sheet 2. Next, by reversing the document reversing roll 51, the document 41 is transported again to the document transport path 44 via a transport path switching member (not shown) in a state where the document 41 is turned upside down. And read by the image reading element via the scanning optical system. Thereafter, the document 41 from which the images on the front and back sides have been read is discharged onto a document discharge tray by the document reversing roll 51.

As described above, the document 41 is fixed and placed on the image reading unit side of the image reading apparatus, so that the platen glass 50 for reading the image of the document 41 and the document are fixed. And an image reading section 48 for reading an image of the document while automatically transporting the document at the speed. In addition, above the image reading device,
As described above, the automatic document feeder 40 having a function as a document pressing member is provided so as to be freely opened and closed.
The automatic document feeder 40 is provided with a platen cover 54 for pressing the document 41 at a position corresponding to an upper portion of the platen glass 50.

The image reading apparatus includes a first measuring means for measuring a length of the original when the original is transported, a second measuring means for measuring the length of an image to be read on the original, and the first reading means. Magnification calculating means for calculating the magnification of the image to be read from the length of the document measured by the measuring means and the length of the image of the document measured by the second measuring means; Image reading operation control means for outputting an image read at a corresponding magnification, measuring the length of the document before reading the image on the first side of the document, and performing the first reading of the document based on the measurement result. Face and second
The image reading magnification of the surface is controlled.

FIG. 15 is a block diagram showing the control means of the image reading apparatus constructed as described above.

In FIG. 15, reference numeral 61 denotes a CPU for controlling the operation of the image reading apparatus; 62, a ROM (read only memory); 63, a RAM (random access memory);
4 is an image reading means 66, a document feed roll 43,
Control of the document reversing roll 51 and the sensor 47,
An I / O port for recognizing input values such as signals from 53 and 55 and controlling the time measuring means 67, and 65 indicates an image rotating means for rotating the read image. The image rotation means 65 and the I / O port 64 and the like
It is controlled by the CPU 61. Also, the image rotation means 6
Reference numeral 5 denotes a memory for storing the read image and an ASIC for controlling reading of the stored image.

With the above configuration, the image reading apparatus according to this embodiment can read an image of an original on the front and back sides even if the original length or the original feeding speed varies as follows. The position and the image are prevented from being shifted between the image of the document and the read image.

Next, a specific operation will be described with reference to flowcharts shown in FIGS.

First, in the image reading apparatus, when the image reading operation is started, as shown in FIG. 16, the feeding of the document 41 is started (step 51), and the document 41 is conveyed one by one by the document feed roll 43. You. The document 41 conveyed by the document feed roll 43
Turns on the document detection sensor 55 (step 5
2). Then, at the same time when the original 41 turns on the original detection sensor 55, the CPU 61 starts time measurement by the time measuring means 67, the original 41 passes through the original detection sensor 55, and the original detection sensor 55
Simultaneously with the FF, the time measurement is ended by the time measuring means 67 (step 53). And the CPU 61
Calculates the size of the document 41 based on the passage time of the document 41 measured by the time measuring means 67 (step 5).
4).

Next, the fed document 41 turns on the document detection sensor 47 (step 55). Manuscript 41
After the document detection sensor 47 is turned on, the time measurement is started by the time measuring means 67, and it is determined whether or not a predetermined time has elapsed (step 56), and the leading end of the document 41 reaches the image reading section 48. After a lapse of time, image reading is started, and counting of the number of read lines is started (step 56). When the conveyed document 41 sets the document detection sensor 47 to 0FF (step 57),
After a fixed time, the image reading is completed (step 58),
The rear end of the document 41 is made to coincide with the end of the image reading.

Then, the number M of read lines in the sub-scanning direction counted when the image reading is completed is stored in a memory provided in the image reading means (step 5).
9). As shown in FIG. 17, the conveyed document 41 turns on the document detection sensor 53 and reaches the document reversing roll 51 (step 60). The document reversing roll 51 is driven to convey the document 41 toward the discharge tray 52. The conveyed document 41 sets the document detection sensor 53 to OF.
F (Step 61), after a certain period of time, the document transport roll 51 is reversed, and the document 41 is transported in the direction of the document transport roll 45 (Step 62). When the document 41 turns on the document detection sensor 47 (step 63), the image reading is started after the time when the leading end of the document 41 reaches the image reading unit 48, and the image is started to be stored in the memory of the image rotating unit 65. (Step 64). When the conveyed document 41 turns off the document detection sensor 47 (step 65), the image storage is terminated after a certain period of time, and the end of the document is coincident with the end of image reading (step 6).
6). As shown in FIG. 18, the conveyed document 41 turns on the document detection sensor 53, reaches the document reversing roll 51, and is discharged to the discharge tray 52 (step 67).

Thereafter, the CPU 61 determines whether or not the magnification change is permitted by a mode selection means (not shown) of the operation panel (step 68). If the magnification change is not permitted, the CPU 61 immediately outputs an image. To end the operation.

On the other hand, when the magnification change is permitted, the CPU 61
, The size M of the document 41 is calculated, and the size M of the document 41 and the image size S (usually a standard size)
Then, the image reading magnification is calculated (step 69).

If the size M of the document 41 is larger than the image size S (usually a standard size), the CPU 61 reduces the read image by S / M times and outputs it (step 71). If the size M of the document 41 is smaller than the image size S (usually a standard size), the read image is enlarged and output by S / M times (step 7).
2) If the size M of the document 41 is equal to the image size S (usually a standard size), the read image is output as it is (step 73).

As described above, it is possible to provide an image reading apparatus in which there is no deviation between the image position of the front and back surfaces and the image position of the document even when the document length or the document feeding speed varies. It becomes possible.

Embodiment 3-1 FIG. 19 is a schematic configuration diagram showing an electrophotographic copying machine as an image forming apparatus according to Embodiment 3 of the present invention.

In FIG. 19, reference numeral 71 denotes a housing of the electrophotographic copying machine. At the upper end of the electrophotographic copying machine, an image reading device 73 for reading an image of a document 72 is arranged. The upper portion of the image reading device 73 has a function as a document pressing member that presses a document 72 placed on a first platen glass, which will be described later, and a function of moving the document 72 on the second platen glass at a constant speed. The automatic document feeder 74, which also has an automatic document feed function for conveying,
It is arranged to be freely openable and closable with respect to the copier housing 71.

As shown in FIG. 20, the automatic document feeder 74 has a document set tray 75 on which a plurality of documents 72 to be copied are set with the copy side up. The plurality of originals 72 set on the uppermost original 7 are moved by a nudger roll 75a.
2 and are sent to a feed roll 76 and a retard roll 77. A document feed sensor 9 for detecting the feed state of the document 72 is provided at the rear end of the feed roll 76 and the retard roll 77.
8 are arranged. Then, the document 72 is separated one by one by the feed roll 76 and the retard roll 77, and the transport path 78 formed in a substantially arc shape.
Is transported to a reading position on the second platen glass 80 by a plurality of takeaway rolls 79 provided on the way. While the document 72 conveyed to the reading position on the second platen glass 80 is conveyed at a constant speed by a document conveyance roll 81 disposed above the second platen glass 80, FIG. Are read by an image reading element 83 such as a CCD via a scanning optical system 82 of the image reading apparatus stopped at the position shown in FIG. The scanning optical system 82 includes an illumination lamp 84 for illuminating the original 72, a full-rate mirror 85 for reflecting an optical image of the original 72 illuminated by the illumination lamp 84, and a light image from the full-rate mirror 85 to be turned back. The two half-rate mirrors 86 and 87 that reflect light, and an image-forming lens 88 that forms an optical image of the document 72 reflected by the half-rate mirrors 86 and 87 on the image reading element 83 in a reduced state. It is configured.

When reading the image of the original 72 moving at a constant speed on the second platen glass 80 by the image reading device 73, as shown in FIG. The image of the original 72 is read with the scanning optical system 82 stopped so as to come to a reading position immediately below the glass 80. When the image reading device 73 reads the image of the original 72 placed on the first platen glass 89, the illumination lamp 80, the full-rate mirror 85, and the half-rate mirrors 86 and 87 The original 72 is scanned by scanning along the lower surface of the document at a speed ratio of 1: 1/2.
Is read.

Thereafter, the original 72 read at the reading position on the second platen glass 80 is transferred to a tri-roll 90 where the original transport roll 81 and the three rolls are pressed against each other.
The conveyance path is switched by the conveyance path switching member 91 via the document feed tray 8, and the document discharge tray 8 provided below the document set tray 75 by the discharge roll 92.
3 is discharged.

The automatic document feeder 74 uses the original 7
In the case of performing double-sided copying of No. 2, the original 72 on which an image on one side has been read is not directly discharged onto the original discharge tray 93 by the discharge roll 92, and the transport path switching member 9 is used.
By switching the transport path by 1, the original 72 on which one side of the image has been read is temporarily stored in the original temporary storage section 95 below the original discharge tray 93 by the transport roll 94, and the rear end of the original 72 is held between the transport rolls 94. During this operation, the transport roll 94 is temporarily stopped. Next, by reversing the transport roll 94, the original 72 is transported again to the transport path 78 via the transport path switching member 91 in a state where the original 72 is turned upside down, and the back side of the original 72 is placed on the second platen glass 80. To the reading position, and the scanning optical system 8
2 is read by the image reading device 73. Then, the original 72 from which the images on the front and back sides have been read is
When the conveyance path is switched by the conveyance path switching member 91 via the document conveyance roll 81 and the tri-roll 90, the document set tray 9 is conveyed by the conveyance roll 94.
The document is temporarily stored in a lower original temporary storage unit 95. The original 72 stored in the original temporary storage section 95 is
By rotating the transport roll 94 in the reverse direction while the trailing end is held between the transport rolls 94, the original 72 is turned upside down and the output tray 8 is turned through the U-turn path 96.
The document 72 is discharged onto the document 3 with the surface of the document 72 facing down.

As described above, the original 72 is mounted on the upper end of the electrophotographic copying machine housing 71 in a fixed state, so that the first image having a large area for reading the image of the original 72 is obtained. A platen glass 89 and a second platen glass 80 having a small area for reading an image of the original 72 while automatically transporting the original 72 at a constant speed.
And are arranged. Also, the electrophotographic copying machine housing 7
As described above, an automatic document feeder 74 also having a function as a document pressing member is disposed above and below the document feeder 1 so as to be openable and closable.
At the position corresponding to the upper part of the platen glass 89 of the
A document pressing member 97 made of an elastic member for pressing the document 2 is provided.

In the above-described electrophotographic copying apparatus, as shown in FIG. 19, the image information of the original 72 is read by the image reading device 73 and the automatic document feeder 74 configured as described above. The image information of the document 72 read by the image reading device 73 is stored in a temporary storage device (not shown), subjected to predetermined image processing as needed, and ROS (Rast
The image exposure is performed on the photosensitive drum 100 by an er Output Scanner (99) to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 100 is developed by a developing device 101 to be a toner image, and this toner image is transferred onto a transfer sheet 103 by a transfer charger 102. The transfer paper 103 is fed with paper of a predetermined size from a plurality of paper trays 104 to 107 housed in a lower part of the electrophotographic copying machine housing 71 and detected by feed sensors 108 to 111. Thereafter, the plurality of transport rolls 112 are once transported to a registration roll 113 in front of the photoconductor drum 100, and synchronized with a toner image formed on the photoconductor drum 100 by the registration roll 113,
The photosensitive drum 100 is conveyed to the surface.

The transfer paper 103 on which the toner image has been transferred from the photosensitive drum 100 is separated from the photosensitive drum 100 by the separation charger 114, and then the transfer belt 11
5 to the fixing device 116, where the fixing device 11
6, the toner image is fixed on the transfer paper 103 by heat and pressure, and the discharge tray 117 disposed outside the apparatus.
And the image copying process is completed.

The cleaning device 118 removes residual toner and paper dust from the surface of the photosensitive drum after the toner image transfer process is completed, so that the surface is ready for the next transfer process.

When performing double-sided copying with the above-described electrophotographic copying machine, transfer paper 103 having an image copied on one side is used.
Is transported once to the sheet reversing path 119 by switching the transport path without directly discharging the sheet to the discharge tray 117, and the transfer sheet 103 is turned upside down via the transport path 120 in a state where the transfer paper 103 is turned upside down. By transferring the image again on the back surface of the transfer sheet 103 by transporting the transfer sheet 103 to the image forming unit again, the transfer sheet 103 is discharged onto a discharge tray 117.

FIG. 21 is a block diagram showing control means of the electrophotographic copying machine according to the third embodiment of the present invention.

In FIG. 21, 131 is a CPU for controlling the operation of the electrophotographic copying machine, 132 is a ROM (Read Only Memory), 133 is a RAM (Random Access Memory), 134 is an image reading device 73, and the automatic document feeder 7
4. I / O for controlling the document feed roll 76, the registration roll, recognizing input values such as signals from the sensors 108 to 111, and controlling the time measuring means 135.
Ports 135 represent image rotating means for rotating the read image. Image rotation means 136
The I / O port 134 and the like are controlled by the CPU 131. The image rotation means 135 is composed of a memory for storing the read image and an ASIC for controlling reading of the stored image.

In the above-described electrophotographic copying machine, when an image is copied from the original 72 having an image formed on one side to both sides of the transfer sheet 103, as described in the second embodiment, Since the image of the original 72 is sequentially read and the original is not inverted by the reversing unit, only the front surface of the original 72 is read and discharged as it is. Copying of the image of the document 72 is performed as in the first embodiment.

In this way, when the single-sided document 72 is sequentially read and printed on both sides of the transfer paper 103, even if the length of the transfer paper 103 or the paper feeding speed varies, the image position on the paper front surface and the paper back surface and It is possible to provide a copying machine in which there is no deviation from a document image.

Embodiment 3-2 In the case of double-sided to double-sided, when reading the image on the back side of the document 72, the reading magnification is not changed, and
As in the second embodiment, both sides of the document 72 are read. At this time, the length M of the document 72 in the sub-scanning direction is detected and stored. Next, the length L of the transfer sheet 103 in the sub-scanning direction is detected and stored as in the first embodiment. And the CPU 13
1 calculates the image forming magnification based on the length M of the original 72 in the sub-scanning direction and the length L of the transfer paper 103 in the sub-scanning direction, as in the first embodiment, An image forming operation on the back surface is performed.

As described above, when the two-sided originals are sequentially read and copied on both sides of the paper, when the original length or the original feed speed varies, or when the paper length or the original feed speed varies. Thus, it is possible to provide a copying machine in which there is no deviation between the image position on the front surface and the back surface of the paper and between the image on the document and the printed image.

[0103]

As described above, according to the first aspect of the present invention, the measuring means for measuring the length of the recording member during conveyance, and the length of the recording member measured by the measuring means. Magnification calculating means for calculating the magnification of the image to be recorded from the length of the image information to be recorded on the recording member, and image forming operation control means for forming an image at a magnification according to the calculation result of the magnification calculating means. The length of the recording member is measured before an image is formed on the first surface of the recording member, and the first and second surfaces of the recording member are measured based on the measurement result.
Since the image forming magnification of the surface is controlled, the length of the recording member is measured before an image is formed on the first surface of the recording member, and the first surface of the recording member and the length of the recording member are measured based on the measurement result. By controlling the image forming magnification of the second surface, even if the length of the recording member or the feeding speed of the recording member varies, the image positions of the first surface and the second surface do not shift. Needless to say, it is possible to prevent a shift between the original image and the printed image.

According to the fifth aspect of the present invention, the first measuring means for measuring the length of the original when the original is transported, and the second measuring means for measuring the length of the image to be read on the original Means, a magnification calculating means for calculating a magnification of an image to be read from a length of the document measured by the first measuring means and a length of the image of the document measured by the second measuring means; Image reading operation control means for outputting an image read at a magnification corresponding to the calculation result of the calculation means, and measuring the length of the document before reading the image on the first side of the document; Since the image reading magnification of the first and second sides of the original is controlled based on the original, the length of the original is measured before reading the image of the first side of the original, and based on the measurement result, Image reading magnification of the first and second sides of the original By controlling the, the feed rate of the length or the original of the document, even if there are variations,
It is possible to prevent a shift between the original image and the read image, as well as to prevent a shift between the image positions of the first surface and the second surface.

According to the invention described in claim 6,
A first measuring unit for measuring the length of the original during transport, a second measuring unit for measuring the length of the transfer member during transport, and the length of the original measured by the first measuring unit. Magnification calculating means for calculating the magnification of an image to be formed from the length of the transfer member measured by the second measuring means; and image forming operation control for forming an image at a magnification corresponding to the calculation result of the magnification calculating means. Means for measuring the length of the original at the time of reading, and measuring the length of the transfer member before forming an image on the first surface of the transfer member,
Based on these measurement results, the first surface and the second surface of the transfer member
Since the image forming magnification of the surface is controlled, the length of the original is measured at the time of reading, and the length of the transfer member is measured before forming an image on the first surface of the transfer member.
Based on these measurement results, the first surface and the second surface of the transfer member
By controlling the image forming magnification of the first surface, even if the length of the original or the feed speed of the original, or the length of the transfer member or the feed speed of the transfer member varies, the image on the first surface and the second surface can be changed. It is possible to prevent a displacement from occurring between the image of the original and the image of the transfer member, as well as to prevent the displacement from occurring.

[Brief description of the drawings]

FIG. 1 is a conceptual explanatory view of an image recording apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram showing an image recording apparatus using laser xerography according to one embodiment of the present invention.

FIG. 3 is a block diagram showing control means of an image recording apparatus using laser xerography according to one embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a control state of image recording.

FIG. 5 is a flowchart showing an image recording operation.

FIG. 6 is a flowchart showing an image recording operation.

FIG. 7 is a flowchart showing an image recording operation.

FIG. 8 is a flowchart showing an image recording operation.

FIG. 9 is an explanatory diagram showing a method of changing a recording magnification of an image.

FIG. 10 is an explanatory diagram showing a method of changing a recording magnification of an image.

FIG. 11 is an explanatory diagram showing a method of writing image information.

FIG. 12 is an explanatory diagram showing a method of writing image information.

FIG. 13 is an explanatory diagram showing a method of writing image information.

FIG. 14 is a schematic configuration diagram showing an image reading apparatus according to Embodiment 2 of the present invention.

FIG. 15 is a block diagram showing control means of the image reading apparatus according to Embodiment 2 of the present invention.

FIG. 16 is a flowchart showing an image reading operation.

FIG. 17 is a flowchart showing an image reading operation.

FIG. 18 is a flowchart showing an image reading operation.

FIG. 19 is a schematic configuration diagram illustrating an image forming apparatus according to Embodiment 3 of the present invention.

FIG. 20 is a configuration diagram illustrating an automatic document feeder used in the image forming apparatus.

FIG. 21 is a block diagram showing control means of the image forming apparatus according to Embodiment 3 of the present invention.

FIG. 22 is an explanatory diagram showing a conventional image information writing method.

FIG. 23 is an explanatory diagram showing a conventional method of writing image information.

FIG. 24 is an explanatory diagram showing a conventional image information writing method.

FIG. 25 is an explanatory diagram showing a conventional image information writing method.

FIG. 26 is an explanatory diagram showing a conventional image information writing method.

[Explanation of symbols]

01 recording member, 02 measuring means, 03 magnification calculating means, 04 image forming operation control means.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/393 B41J 3/00 S 5C076 9A001 F term (Reference) 2C062 RA06 2C087 AA18 AC08 BD06 BD24 CB12 2H027 DC10 FA13 FB12 2H028 BA03 BA16 BB06 5C072 AA01 AA03 AA05 CA06 HA02 JA07 LA04 NA01 NA05 RA01 SA03 UA11 UA13 WA02 XA01 XA04 5C076 AA02 AA24 AA37 BA02 BA03 BA06 CB04 9A001 HH24 JJ35

Claims (6)

[Claims] An image recording apparatus capable of recording an image on both sides of a recording member, a measuring unit for measuring a length of the recording member during conveyance, a length of the recording member measured by the measuring unit, and the recording member A magnification calculating means for calculating the magnification of the image to be recorded from the length of the image information to be recorded, and an image forming operation control means for forming an image at a magnification according to the calculation result of the magnification calculating means. Before forming an image on the first surface of the recording member, the length of the recording member is measured, and the first surface and the second
An image recording apparatus for controlling an image forming magnification of a surface. 2. The image recording apparatus according to claim 1, wherein an image is formed on the second surface of the recording member by rotating the image. 3. The image processing apparatus according to claim 1, further comprising a mode selection unit configured to select whether or not the image forming magnification can be changed.
Or the image recording device according to 2. 4. The image forming apparatus according to claim 1, wherein when the calculation result of said magnification calculation means exceeds a predetermined value, the change of the magnification by the image forming operation control means is prohibited. Image recording device. 5. An image reading apparatus capable of reading images on both sides of a document, a first measuring means for measuring a length of the document when it is transported, and a second measuring means for measuring the length of an image to be read on the document. Measuring means, and a magnification calculating means for calculating a magnification of an image to be read from the length of the document measured by the first measuring means and the length of the document image measured by the second measuring means, Image reading operation control means for outputting an image read at a magnification corresponding to the calculation result of the magnification calculation means, and measuring the length of the document before reading the image on the first side of the document; An image reading apparatus, wherein an image reading magnification of a first surface and a second surface of a document is controlled based on a result. 6. An image forming apparatus capable of forming an image of a document on both sides of a transfer member, a first measuring means for measuring a length of the document when transported, and measuring a length of the transfer member when transported. Second measuring means, and magnification calculating means for calculating a magnification of an image to be formed from the length of the document measured by the first measuring means and the length of the transfer member measured by the second measuring means. And an image forming operation control means for forming an image at a magnification corresponding to the calculation result of the magnification calculation means, which measures the length of the original at the time of reading and forms an image on the first surface of the transfer member. An image forming apparatus comprising: measuring a length of a transfer member beforehand; and controlling an image forming magnification of a first surface and a second surface of the transfer member based on a result of the measurement.