JPH0749494Y2 - Copier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a copying machine, and more particularly to a copying machine capable of obtaining a copy from a document having a size equal to or larger than a contact glass.

2. Description of the Related Art In copying with a copying machine, it may be necessary to copy an original having a size larger than that of a contact glass. In such a case, a so-called sheet in which an original document is conveyed on the contact glass at a constant speed, and an original document passing through a constant position is read by an exposure scanning unit stationary at a constant position to form an image on a photoconductor. 2. Description of the Related Art Conventionally, a copying machine configured to copy in a through mode is known.

However, conventionally, in a copying machine capable of such an operation, when the sheet through mode is set, the exposure scanning unit moves to the document scanning position for the sheet through mode. Generally, the document scanning position in the sheet through mode is set near the home position of the exposure scanning unit in the normal copying mode (sheet fixing mode). The reason is to shorten the moving distance of the scanning unit at the time of mode switching.

By the way, the home position of the exposure scanning unit in the sheet fixing mode is often set at one end of the unit movement path. Therefore, the document scanning position in the sheet through mode is near the home position in the unit moving path.

When the sheet scanning mode is set, when the exposure scanning unit is moved from the home position to the document scanning position and stopped, the stop position varies due to friction between the scanning unit and its supporting member and inertial force of the scanning unit. . When the stop position of the scanning unit in the sheet-through mode varies, the copy image and the copy sheet are misaligned, which is not preferable.

SUMMARY OF THE INVENTION The present invention has a sheet fixing mode and a sheet through mode in consideration of the above-mentioned actual situation of a conventional copying machine, and can copy a document having a size equal to or larger than the size of the contact glass. It is an object of the present invention to provide a copying machine which can perform the alignment of a copied image and a copy sheet with high accuracy.

Means for Solving the Problems In order to solve the above problems, the present invention provides a contact glass on which a document is placed, an exposure scanning unit for exposing and scanning the document on the contact glass, and the contact glass at a constant speed. A sheet fixing mode for moving the exposure scanning unit to perform exposure scanning of a document placed on the contact glass at a constant speed; A copying machine having a sheet-through mode in which the exposure scanning unit is stopped at a predetermined position other than both ends of the movement path, the document is conveyed by the document conveying means at a constant speed, and the document is exposed and scanned at the predetermined exposure position. In the sheet through mode setting means for setting the sheet through mode, and when the sheet through mode is set by the setting means, Stop position detection means for detecting the exposure scanning unit stop position when the optical scanning unit is moved from the home position to the predetermined position and stopped, and the sheet through mode is set by the setting signal of the sheet through mode setting means. In addition, it is characterized in that control means is provided for controlling so as to align the image and the copy paper based on the detection result of the stop position detection means.

With the above configuration, even when the stop position of the exposure scanning unit in the sheet through mode varies, the image and the copy sheet are positioned based on the detection result of the stop position detecting means for detecting the stop position. Since they are controlled so that they are aligned with each other, the alignment of the copy image and the copy paper is performed with high accuracy.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a main part of a copying machine main body as an embodiment of the present invention, and a state in which a detachable document conveying unit is mounted at a predetermined position.

A contact glass 2 on which a document is placed is provided on the top plate of the copying machine main body 1, and an illumination unit 4 including a halogen lamp 3 and a first mirror 5, a second mirror 6, a third mirror 7, and a lens 8 are provided immediately below the contact glass 2. , An exposure linear system 10 in which a fourth mirror 9 is arranged as shown in the figure is provided, and the position of the peripheral surface comes to a position where the reflected light of the original document irradiated to the illumination unit 4 by the exposure linear system forms an image. Thus, the photoconductor drum 11 is provided. Around the photosensitive drum 11, in the order of the rotation direction shown by the arrow, the charging charger 12, the eraser 13, the exposure position 14, the developing unit 15 using the two-component developer, the transfer charger 16, the separation charger 17, the separation claw. 18, cleaning unit 19, quenching charger 20, static elimination lamp 21
Is provided.

The illumination unit 4 and the first mirror of the above-mentioned exposure science system 10 are carried by a member which can be moved integrally to form a first scanner 22, and the second mirror 6 and the third mirror 7 are integrally connected to each other. The second scanner 23 is supported by a movable member and constitutes the second scanner 23. During normal equal-magnification copying, the first scanner 22 is synchronized at a constant speed and the second scanner 23 is synchronized with the original at a speed half that of the original. Then, the photosensitive drum 11 is rotated at the same peripheral speed as the speed of the first scanner, so that the document exposure is performed. Since the image forming process after exposure is publicly known, description thereof will be omitted. The home position of the first scanner 22 is slightly upstream of the position where the edge of the original placing range of the contact glass 2 is irradiated,
The arrival of the first scanner 22 at the home position is detected by operating the home sensor 25 by the operating piece (blocking member) 24 fixed to the first scanner.

On the lower surface of the contact glass 2, a reference pattern 26 of a predetermined density is attached to the irradiation position of the illumination unit 4 of the first scanner 22 at the home position, and the reference pattern 26 of a predetermined density is applied once every predetermined number of times (for example, 5 times) of image formation. The first scanner 22 in the position reads the reference pattern 26, forms a latent image on the photoconductor drum 11, and develops it in the developing unit 15 to form a toner pattern, which is downstream of the developing unit of the photoconductor drum 11. The density is read by a pattern sensor (P sensor) 27 provided on the side, and when the density reaches a predetermined value as compared with the background density on the surface of the photosensitive drum, a certain amount of toner is applied to the developing unit 15. Image density control is performed so that replenishment is performed and the image is always developed to a predetermined image density. In the apparatus of this embodiment, the toner replenishment to the developing unit is provided at the bottom of the toner tank 29 with a toner replenishing roller 28 connected via a clutch to a developing motor (not shown) that rotates in synchronization with the main motor. The clutch is turned on and off by a toner replenishment signal generated by the ratio of the pattern density detected by the pattern sensor and the background density. Since the amount of toner consumption varies depending on the paper size, the ON time for toner replenishment is determined by the paper size.
After the density of the toner pattern is read by the pattern sensor, the toner pattern is cleaned and erased by the cleaning unit.

In the present embodiment, unlike the conventional copying machine, the document conveying unit (sheet through unit) 30 can be detachably mounted at a predetermined position on the contact glass 2 of the copying machine.

As shown in the figure, the sheet through unit 30 is provided with a conveyance roller 31 that rotates counterclockwise, and around it, a document insertion opening 33 having an entrance sensor 32 and a driven roller in the order of the rotation direction shown by an arrow. 34, stop sensor 35, stopper 3
6. An exposure irradiation position 37 is provided. The driven roller 34 is a solenoid SOL1 and the stopper 36 is a solenoid SOL2, which is brought into contact with or separated from the conveyance roller 31, respectively. The original that has passed through the exposure illumination position 37 on the upper surface of the contact glass 2 advances along the upper surface of the contact glass 2 and is then discharged to the original receiver 39 by the paper discharge roller 38. The transport roller 31 and the paper discharge roller 38 are rotated at a constant peripheral speed by a drive motor 40 in synchronization. Paper ejection roller 38
A paper discharge sensor 41 is provided at a position immediately upstream of the above. When the sheet through unit 30 is set at a predetermined position on the contact glass 2 of the copying machine, the magnet 42 provided on the sheet through unit 30 side activates the unit detection sensor 43 provided at the opposite position of the copying machine main body. Then, it is input to a control device which will be described later, and in a state where the first and second scanners 22 and 23 of the exposure science system 10 are stopped, a sheet through mode for exposing and scanning a document moving at a constant speed is set. In this case, the first scanner is provided with the illumination unit fixing sensor 44 at a position for detecting the actuating piece 24 fixed to the first scanner 22 when the illumination unit comes to a position where the exposure position 37 is irradiated. The one scanner 22 is fixed at this position.

By the way, as an example, it is assumed that the contact glass 2 has a maximum size of A3 and can be placed so that the scanning direction is the lateral direction. When exposing and copying A2 size originals with this copier, the length of the short side of the A2 size is equal to the length of the long side of the A3 size. In addition, if the sheet is conveyed by the sheet through unit 30, the exposure scanning can be performed.

If you have a paper feed device that can feed A2 size vertically as the size of the transfer paper, you can copy the same size, but considering that the frequency of copying A2 size is low, A3 size paper is Sekinoyama is equipped with a paper feeding device. In that case, the reduction ratio is about 71%. Therefore, when the sheet through mode is set, the second scanner 23 and the lens 8 are automatically displaced to a position where a conjugate length with a reduction rate of about 71% is obtained.

The document exposure in the sheet through mode is performed as follows. When you insert an A2 size original from the original insertion port 33,
The entrance sensor 32 operates, the drive motor 40 is rotated, and the transport roller 31 and the paper discharge roller 38 are rotated counterclockwise.
When the document is sent by the transport roller 31 and the stop sensor 35 detects the leading edge of the document, the drive motor 40 stops, and the transport roller 31 and the paper discharge roller 38 stop. When the original is set, the stopper 36 is in contact with the conveying roller 31 and the driven roller 34 is separated from the conveying roller 31, so the original is conveyed to the stopper while sliding only by the conveying roller, and the leading end is placed on the stopper 36. To be struck. Further, even when the document is inserted in a bent state due to a document insertion error, it can be pulled back by hand and re-inserted.

Next, when you press the start key of the copier, the drive motor 4
0, the solenoids SOL1 and SOL2 are turned on, the driven roller 34 is pressed by the conveyance roller 31, the stopper 36 is retracted from the conveyance roller 31, and the halogen lamp 3 of the illumination unit 4 is turned on.
The original is exposed by being conveyed through the exposure position 37, and a latent image with a reduction ratio of 71% is formed on the photosensitive drum 11. When the document passes the contact glass surface, the paper discharge sensor 41 is turned on, and the paper is discharged to the document receiver 39 by the paper discharge roller 38. The latent image formed on the photosensitive drum 11 is visualized by a normal copying process, transferred onto a transfer paper and fixed, and a reduced copy is obtained.

The paper discharge sensor 41 of the sheet through unit 30 is used for detecting a jam of a document.

When the sheet through unit 30 is removed from the copying machine main body 1, the magnet 42 separates from the unit detecting sensor 43 and the unit detecting sensor 43 is turned off. This signal is input to the control device, and the sheet through mode is automatically released. , The lens 8 and the second and third mirrors 6 and 7 are returned to the positions at the same magnification ratio.

During a normal copying operation, the scanner starts from the home position, scans the width of the document, and then returns to the home position. Therefore, the halogen lamp 3 should be turned on at the timing of pattern formation for toner density control.ゝ (Normally goes out at the start of returning) Goes back to the home position, creates a pattern, and goes out. But,
In the sheet-through mode, the lighting unit 4 remains stopped at the position where the lighting unit fixing sensor 44 detects the actuating piece 24, and therefore the halogen lamp 3 is turned on at the pattern creation timing (usually, the original is It goes out when it passes.) After moving to the home position, creating a pattern, turning off the halogen lamp, returning to the position of the illumination unit fixing sensor 44 again, and waiting for the next original.

FIG. 2 is a block diagram of the control system of the copying machine of this embodiment. This control system is a microcomputer system including a CPU 300, a ROM 301, a RAM 302, an IN port 303, an OUT port 304, and an I / O port. I wrote the program
The ROM controls the copier and the sheet-through unit by using the RAM as needed and receiving various input signals from the IN port and outputting the controlled signals to the OUT port. A backup battery 305 is connected to the RAM to serve as a non-volatile memory.

In addition, TCU (timer control unit) 306 is CPU3
It is connected to 00 via a bus, and the output terminal of the TCU306 is connected to the interrupt input terminal (INT) of the CPU. The TCU is a timer IC that is activated by a program, and in this case, it is programmed to output a square wave. TC
The square wave output from U306 is an interrupt input pin (INT).
By doing so, it is possible to periodically execute the interrupt processing program.

FIG. 3 is a diagram showing a portion of the operation unit of the copying machine of this embodiment, which is relevant to the present invention.

In the figure, reference numeral 201 is a start key for instructing copy start, 202 is a ten-key for inputting the number of copy sets, etc., 203 is a clear / stop key for instructing clearing of the number and copy stop, and 204 is a copy set. The set number indicator that displays the number of sheets, 205 the number of copies indicator that displays the number of copies, 206 the number of originals indicator that displays the number of originals, and 207 the paper size that indicates the size of the paper set in the paper tray A display unit, 208 is a paper remaining amount indicator that displays the remaining amount of paper set in each paper tray, and 209 is an automatic paper selection mode that automatically selects the optimum copy paper from the document size information. Is displayed, 210 is a paper key for selecting copy paper, 211 is a paper size selection display that displays the selected paper size, and 212 is a copy machine standard. "Please wait" indicator that indicates the inside, 213 is a "ready to copy" indicator that indicates that the copier is ready, 214 is a document jam indicator that warns of a document jam in the sheet-through unit, and 215 is a copy Paper jam indicator to warn of copy paper jam of machine, 216 is a paper supply indicator to warn that there is no selected copy paper, and 217 is a mode to make a double-sided copy from two single-sided originals "One side →
"Double-sided mode" key, 220 is an indicator for indicating that the mode is set, 218 is a "double-sided → double-sided mode" key for instructing a mode for copying one double-sided original on both sides of one sheet, 221 is a display device that indicates that the mode is set, and 219 is a “single-sided to composite mode” in which images of two single-sided originals are copied on the same side of copy paper.
Key, 222 is an indicator indicating that the mode is set, 223 is an interrupt key for indicating the interrupt mode, 224 is an interrupt mode indicator indicating that the interrupt mode is set, and 225 is A magnification key for setting the copy magnification, and a magnification display 226 for displaying the magnification.

FIG. 4 is a diagram showing respective timings of the main motor of the copying machine, the paper feed clutch for feeding the copy paper, the halogen bulb for exposing the original, and the sheet through unit drive motor for feeding the original.

When the start key is turned on, the timing control counter is set to 0, the copying machine main motor is turned on, and the copying operation is started. When the copying operation is started, the timing control counter starts incrementing, and when the counter value reaches a predetermined value, the paper feed clutch is turned on. The predetermined value is
As will be described in detail later, it changes depending on the stop position of the illumination unit and the fine adjustment data of the image position. Therefore, in FIG. 4, the range is indicated by diagonal lines. Paper feed clutch off
Is after a certain time has passed since it was turned on. Therefore,
The OFF timing also changes.

The halogen bulb turns on when the counter value is 200, and the sheet-through unit drive motor for feeding the originals turns on when the counter value is 300.

The sheet-through unit drive motor turns off when the originals have been discharged, and the halogen bulb shows OF when the counter value is 900.
F, and the copier main motor turns O when the copy paper is completely discharged.
FF.

In this way, the image of the original is copied to a predetermined position on the copy paper.

Next, various operations in the case of performing copying in the sheet through mode using the document conveying unit (sheet through unit) will be described with reference to a flowchart.

(1) Detection of Document Conveying Unit Set FIG. 5 is a flowchart of detection of the document conveying unit set.

The document transport unit 30 is installed and the unit detection sensor 43
When is turned on, the seat through mode is set, and the lighting unit 4 moves to the position of the lighting unit fixed sensor 44. At this time, the stop position of the lighting unit is stored (see FIG. 7). The lens 8 and the second and third mirrors 6 and 7 have a reduction ratio of 7
Move to the position where it becomes 1%. This magnification is the magnification for copying an A2 size original onto an A3 size paper. In the sheet through mode, in the case of the present embodiment, double-sided, composite mode prohibited, magnification 71% only, one copy number, interrupt copy mode prohibited. Therefore, the sheet through mode set is:
It means the reset processing of the prohibit mode.

Next, the sheet through mode flag is set to "1" and the process ends. The sheet through mode flag is stored in RAM.

(2) Document Transport Unit Reset Detection
Shown in the figure. When the document transport unit 30 is removed from the copying machine main body 1, the unit detection sensor 43 is turned off. The standard mode is set by the OFF signal of the unit detection sensor,
The exposure unit 4 of the exposure science system moves to the home position detected by the home sensor 25, and resets the seat-through mode flag to "0". As a result, the sheet through mode is released. The standard mode is a mode set when the power of the copying machine is turned on. In the case of this embodiment, the double-sided / composite mode is reset, and the magnification is 10
0%, 1 copy, interrupt reset mode reset state.

(3) Moving the lighting unit to the position of the lighting unit fixing sensor FIG. 7 shows a flow of moving and fixing the lighting unit to a predetermined position in the sheet through mode. During this movement, the pulses of the encoder that rotates in synchronization with the movement of the lighting unit drive motor are counted, and the stop position is stored in RAM. Since the stop position of the lighting unit varies due to friction of the lighting unit or the like, it is necessary to accurately detect the position.

First, turn on the lighting unit drive motor and clear the position memory counter in RAM. Then wait for the lighting unit to start moving and exit the home sensor. After exiting the home sensor and turning off the home sensor, the encoder pulses are counted from here, and counting continues until the lighting unit turns on the fixed sensor, and the counted value is put into the position memory counter and stored.
Then, after the fixed sensor is turned on, the drive motor is turned off, and the process ends.

(4) Copying Operation FIG. 8 shows a flow of copying operation in the sheet through mode.

First, it waits for the entrance sensor 32 of the document feeding unit 30 to be turned on. Before the document is set in the document transport unit, the "Ready to copy" indicator 213 is turned off and the document is set. When a document is set, the entrance sensor 32 turns on,
Turn on the "Ready to copy" indicator and start key 20
Wait for ON of 1. When the start key 201 is turned on, the "ready for copying" display 213 is turned off, the "please wait" display is turned on, and the main motor of the copying machine is turned on. This makes it possible to convey the copy paper. Next, the paper feed clutch is turned on to feed the copy paper. The paper feed timing at this time is a predetermined timing (see (6) Paper feed control of copy paper). Turn on the halogen lamp 3 and feed the original. By feeding the original, the image is read and the image forming operation is executed. After the image forming operation is completed, turn off the halogen lamp.
And wait for the copy paper to be ejected. When the copying paper is completely discharged, the main motor of the copying machine is turned off, the "Please wait" indicator is turned off, and all copying operations are completed.

(5) Processing by timer interrupt TCU (timer control unit) shown in Fig. 2
9 shows the flow of the program executed by the interrupt signal generated at a predetermined timing. (It has nothing to do with the interrupt key.) First, it is checked whether or not the copying operation is in progress, and if the copying operation is in progress, the timing control counter is incremented. In short, the counter is + for each pulse generated by the TCU.
That is one. The main motor of the copying machine may be checked to see if the copying operation is in progress.

The value of this timing control counter is used for the timing of turning on various loads (paper feed clutch, halogen lamp, etc.).

(6) Copying paper feed control (4) The subroutine of the operation of "feeding copying paper" during the copying operation will be described with reference to FIG.

When the specified timing comes, the paper feed clutch is turned on for a certain time.
Then, the copy paper is fed. The predetermined timing is
Timing is fixed to the sum of the fixed data N ₁ , the fine adjustment data N ₂ input for fine adjustment, and the correction data N ₃ determined by the value of the position storage counter that stores the position of the lighting unit. It is when the value of the control counter reaches.

Although a method of inputting the fine adjustment data is not shown, for example, there is a method using a switch means such as a DIP switch or a rotary switch, or a method of inputting specific data from the operation unit.

The correction data N ₃ is, in short, data obtained by converting the number of pulses of the timing control counter corresponding to one pulse of the encoder of the lighting unit into a distance.

In this way, by correcting the paper feed timing of the copy paper, it is possible to prevent the variation of the image position of the copy paper due to the variation of the stop position of the illumination unit.

(7) Correction of Document Feeding Timing The prevention of the variation in the image position of the copy sheet due to the variation in the stop position of the illumination unit can also be achieved by correcting the document feeding timing. Next, the operation in that case will be described.

In this case, the subroutine of the operation of "feeding the original" during the copying operation described in FIG. 8 is as shown in FIG. In this case, the paper feed timing of the copy paper is determined by the fixed data and does not change. The document feeding control in this case will be described with reference to the flowchart of FIG.

When the predetermined timing comes, the document feeding unit drive motor 40 is turned on to feed the document. OF of this drive motor
F is the time when the trailing edge of the original has passed through the paper ejection sensor 41.

The definition of the predetermined timing and the method of inputting the fine adjustment data are the same as those described in the previous section.

By correcting the document feeding timing as described above, it is possible to prevent the variation in the image position of the copy sheet due to the variation in the stop position of the illumination unit.

Effects As described above, according to the present invention, it is possible to accurately align the copy image and the copy paper in the sheet-through mode that enables copying of a document having a size larger than that of the contact glass. Effective in improving quality.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a main part of a copying machine according to an embodiment of the present invention and a document conveying unit mounted on the copying machine. FIG. 2 is a block diagram of its control system. FIG. 3 is an operation of the copying machine. FIG. 4 is a plan view showing the main part of the apparatus, FIG. 4 is a timing chart relating to the feeding and exposure document feeding, and FIGS. 5 to 11 are the main parts when copying in the sheet through mode in the apparatus of the embodiment. It is a flow chart of operation. 1 ... Copier main body 2 ... Contact glass 3 ... Halogen lamp 4 ... Illumination unit (exposure scanning unit) 26 ... Reference pattern 27 ... Pattern sensor 28 ... Toner supply roller 30 ... Sheet-through unit (original conveying unit) 31 ... Conveying roller 32 … Entrance sensor (document insertion detection means) 44… Lighting unit fixed sensor 300… CPU (control means) 306… TCU (timer control unit)

Claims (3)

[Scope of utility model registration request] 1. A contact glass on which a document is placed, an exposure scanning unit for exposing and scanning the document on the contact glass, and a document transport for transporting the document at a constant speed through a predetermined exposure position on the contact glass. A sheet fixing mode in which the exposure scanning unit is moved to perform exposure scanning of a document placed on the contact glass at a constant speed, and the exposure scanning unit is set to a predetermined position other than both ends of a movement path. In a copying machine having a sheet through mode in which the document is transported at a constant speed by being stopped at a position and is transported at a constant speed by the document transporting means, a sheet through mode setting for setting the sheet through mode is provided. Means and the exposure scanning unit from the home position to the predetermined position when the sheet through mode is set by the setting means. Stop position detecting means for detecting the stop position of the exposure scanning unit when stopped by moving the sheet through mode, and a sheet through mode is set by a setting signal of the sheet through mode setting means, and a detection result of the stop position detecting means And a control means for controlling so that the image and the copy sheet are aligned with each other based on the above. 2. The copying machine according to claim 1, wherein the document conveying timing is corrected based on the detection result of the stop position detecting means to align the image and the copy paper. 3. The copying machine according to claim 1, wherein the copying paper conveyance timing is corrected based on the detection result of the stop position detecting means to align the image and the copying paper.