JPH0475135B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an image recording apparatus, particularly to control of a driving method in an image recording apparatus having a plurality of image forming sections (photosensitive drums, etc.).

[Prior art]

Conventionally, various types of devices for recording images on paper have been put into practical use. For example, copying machines that directly project the original image onto a photoreceptor, visualize it, and record it on paper, or impact copying machines (type type, wire dot type, etc.) that convert image information into electrical signals.
There are also non-impact type (thermal type, inkjet type, etc.) printers that reproduce images on paper.

In recent years, these image recording devices have been required to be more and more sophisticated due to demands such as streamlining office work, especially in terms of output speed (number of sheets processed per hour).
There is a strong desire to improve speed, and efforts have been made to increase the speed of these devices.

However, although there are differences depending on each method, there is a speed that corresponds to that speed, and if you try to increase the speed beyond that, many problems will occur, and to overcome them, it will take a lot of effort to develop new technology. This requires a lot of effort, and the device itself may become complicated and large, making it uneconomical. Taking a copying machine as an example, the original image is guided directly to a photoreceptor and formed into an image, creating a latent image, which is visualized and transferred onto paper, so one original is scanned one time. You can only get a copy of Therefore, in order to increase the speed, it is necessary to increase the machine speed, which may cause problems such as insufficient sensitivity of the photoreceptor, vibration and noise of the machine, and durability. On the other hand,
If you take measures such as increasing the light intensity of the document illumination lamp, many problems will occur, such as the heat generated by the lamp and the temperature of the machine rising.
A complete solution is difficult. Moreover, since this increases exponentially as the speed increases, the upper limit of the speed is naturally limited depending on the balance between the benefits of increasing the speed.

On the other hand, in order to conserve resources and file space, things that were previously recorded on one side of the paper are now recorded on both sides of the paper, just like in general printing, to reduce the number of sheets of paper used. There is a demand to reduce Regarding this, a method was proposed and put into practical use in which the sheets recorded on the first side are once accumulated, and after the recording on the first side is completed, the accumulated sheets are fed again and recorded on the second side. Although this is efficient when creating multiple records with the same content, it is extremely inefficient when creating multiple double-sided records with different contents. In other words, when creating pages 1, 2, 3, etc., first record the odd numbered pages 1, 3, 5, etc. on the first side of each sheet, and then refeed the pages after that. Then, pages 2, 4, 6, etc. will be recorded on the back side. If double feeding or a paper jam occurs during this refeeding, the combination of front and back sides will be different from the predetermined combination, and the process will have to be restarted from the beginning. In order to avoid this, it is possible to record the front, back, front, and back of each sheet one by one, but it takes time to refeed the paper and the efficiency is extremely reduced.

In addition, with increasing functionality, there is also a demand for recording two pieces of information on one side of paper in an overlapping manner. In particular, recently, colorization has progressed in various fields, and there is a demand for documents to be easier to read by mixing records in red (for example, by making the title red) instead of just black as in the past. For this,
This was possible with conventional equipment using ink ribbons, etc., but with copiers and laser beam printers that use electrophotography, the equipment becomes extremely large, so it is not suitable for general office use. It has not yet been put into practical use. However, a simple method is to record once in black, then replace the developing device in the device from black to red, and then record on the same side again, but this is extremely time-consuming and time-consuming. Ta.

In order to solve the above problems, unlike conventional electrophotographic devices, multiple image forming units are provided in the device, and these are connected by selectable paper transport paths to speed up image recording. Image recording devices that are capable of double-sided recording, multiplex recording, etc. have been proposed.

1 to 5 are explanatory diagrams of one embodiment of the above-mentioned image recording apparatus, and FIG. 1 is a schematic diagram showing the basic configuration of this embodiment centering on the paper path. 1
is the main body, inside of which are the first image recording section 2 and the second image recording section 2.
image recording section 3, paper handling section 4, first paper feeding section 5,
It is composed of a second paper feed section 6, a first stacker section 7, and a second stacker section 8.

The first and second image recording units 2 and 3 are laser beam printers and have almost the same configuration. Referring to the first image recording section 2, reference numeral 20 denotes a photoreceptor which is rotationally driven, and a known electrophotographic process unit is disposed around it (not shown). A laser beam modulated according to an image signal is scanned and exposed onto the photoreceptor 20 by a laser scanner 22 via a mirror 21, and an image is visualized by a predetermined electrophotographic process. On the other hand, the sheets P ₁ loaded in the first sheet feeding section 5 are transferred one sheet at a time to the sheet feeding path 2 of the first image recording section 2 by a known sheet feeding means 50 such as a roller.
Sent to 3. The fed paper reaches the transfer section 24 in synchronization with the developed image on the photoreceptor 20,
The image is transferred by known transfer means. The paper then reaches the fixing section 25, where the image on the paper is fixed by known means such as heating or pressure, and is discharged to the outside of the first image recording section 2 through the discharge passage 26. In addition,
Conveying means such as rollers and belts are appropriately disposed along the paper passage (not shown).

The second image recording section 3 is different in that, in addition to the paper supply passage 33 that receives the sheets P ₂ accumulated in the second paper feed section 6, there is a second paper passage that receives the sheets from the paper handling section 4. A supply passage 37 is provided. Each paper received from both paper supply passages 23 and 33 is guided to the transfer section 34.

Next, the paper handling section 4 will be explained. The paper handling section 4 includes a carry-in passage 40 connected to the discharge passage 26.
The paper received from the paper is received from the paper output passage 41 to the paper supply passage 37 with or without inversion, or from the second paper output passage 43 to the first stacker section 7 via the paper reversal section 42. It's starting to be handed over. FIG. 2 is a diagram showing the details of the internal configuration of the paper handling section 4, and the rollers 40 of the paper carrying path 40.
0 and 401 each rotate in the direction of the arrow, and a passage switching claw 402 is disposed at the tip thereof. The path switching pawl 402 is swingable about a shaft 403 and is always biased counterclockwise in the drawing by a spring 404 to direct the paper path toward the paper reversing section 42 . Now, when the solenoid 405 is actuated, the passage switching pawl 402 rotates clockwise against the spring 404 and switches the passage to the carry-out passage 41 side. At the entrance of the paper reversing section 42, there is a claw 40 that hangs down due to its own weight.
6 is provided, so that sheets sent from the carry-in path 40 to the left in the figure can push aside the lower surface of the claw 406 and pass through, and sheets returned from the paper reversing section 42 to the right in the figure can pass through the claw 406. It is guided by the upper surface of and faces toward the carry-out passage 41. Claw 4
A paper detector including a lamp 407 and a light receiving element 408 is arranged adjacent to the paper detector 06 . 409,4
10 are a reversing roller and a driven roller, respectively;
The reversing roller 409 is attached to the tip of an arm 411 that is swingable about a shaft 409a, and is constantly rotating in the counterclockwise direction in the drawing. The arm 411 is suspended by a spring 412, and the reversing aura 409 normally has a distance from the driven roller 410, but when the solenoid 413 is activated, the arm 411 swings clockwise and the reversing roller 409 is driven. roller 4
Pressed to 10. The driven roller 410 is rotatably supported, and rotates clockwise when the reversing roller 409 is pressed. Also,
Next to it, there is an endless belt 414 that rotates in the direction of the arrow, and a fan 215 on the lower side attracts the paper to the belt 414 and conveys it to the output path 414.
It is designed to lead to 3.

Next, the operation of the paper handling section 4 will be explained. First, when guiding directly from the carry-in passage 40 to the carry-out passage 41, by activating the solenoid 405,
The passage switching claw 402 switches, and a passage from the carry-in passage 40 to the carry-out passage 41 is formed. Further, when the paper is to be guided to the discharge path 41 after being reversed, the solenoid 405 is not activated and the paper is guided to the paper reversing section 42 . The leading edge of the paper is reversed by roller 4
The belt 41 passes between the roller 09 and the driven roller 410.
4, the paper is fed to the left by the suction force of the fan 415. When the passage of the trailing edge of the paper is detected by the lamp 407 and the light receiving element 408,
The solenoid 413 is activated, and the reversing roller 409 is pressed against the driven roller 410 to sandwich the paper. At this time, since the reversing roller 409 is rotating counterclockwise, the paper is rotated by the fan 415.
It overcomes the force exerted by the belt 414 and is sent to the right in the figure. In other words, what used to be the trailing edge of the paper now becomes the leading edge.

When the leading edge of the new paper reaches the pawl 406, the pawl 406 serves as a guide and the paper is guided to the carry-out path 41, as described above. At this time, the front and back sides of the paper are exchanged, compared to when the paper is led directly to the above-mentioned unloading path 41.

On the other hand, when guiding the paper to the unloading path 43, the solenoid 405 is deactivated and the solenoid 413 is left inactive after the paper is guided to the paper reversing section 42. It is sent to the left by the cooperative action of , and guided as it is to the carry-out passage 43 .

The first and second stacker sections 7 and 8 in FIG.
The sheets discharged from the discharge passage 43 of the paper handling section 4 and the discharge passage 36 of the second image recording section 3 are stacked one after another.

With the above-mentioned device, the aforementioned high-speed recording,
How to cope with double-sided recording and multiplex recording will be explained below.

(1) High-speed recording Figure 3 shows a block diagram for high-speed recording.

The signal _S1 given to this apparatus is distributed to the first and second recording sections 2 and 3, and both image recording sections are operated in parallel. That is, the first image recording section 2 receives the paper P ₁ from the first paper feeding section 5,
An image based on the signal _S1 is recorded on one side of the sheet, and the sheet is delivered to the sheet handling section 4. In the paper handling section 4, the solenoid 405 and the solenoid 413 are inactivated, and the received paper _P1 is discharged from the carry-out passage 43 to the first stacker section 7. On the other hand, the second image recording section 3 receives the paper P ₂ from the second paper feed section 6, records an image on one side of the paper P ₁ according to the same signal S 1, and then passes the paper P ₂ from the discharge path 36 to the second image recording section 3. It is discharged to the stacker section 8.

In this way, the processing capacity per unit time of the first and second image recording sections 2 and 3 can be reduced to N.
The processing capacity of this device as a whole is
This results in 2N sheets per unit time, realizing twice the high speed recording.

(2) Double-sided recording Figure 4 shows a block diagram for double-sided recording.

Recording by the first side image signal S ₂ given to the first side of the paper by the first image recording unit 2 is also performed by the second side.
The apparatus is operated so that the image recording section 3 performs recording using the second side image signal _S3 applied to the second side of the paper.

That is, first, in the first image recording section 2, the first
Paper P ₁ is supplied from the paper feed section 5, and the first
An image based on the signal S ₂ for the first side is recorded on the surface (upper surface in the figure) and delivered to the paper handling section 4 . The paper handling section 4 performs the paper reversing operation described above.
That is, the solenoid 405 is deactivated and the paper P ₁ is sent to the paper reversing unit 42, and then the paper detectors 407 and 408 detect the trailing edge of the paper, so the solenoid 413 is activated, and the paper P ₁ is sent to the paper reversing unit 42. Export passage 4 with the rear end as the tip
1 and is delivered to the second image recording section 3. The transferred paper P ₁ is transferred with the image based on the signal S ₃ for the second side in the transfer unit 34, but since the side receiving the transfer (the upper side in the figure) is subjected to a reversal action, the first image is This is the second surface on the back side of the first surface transferred by the recording unit 2. The paper P ₁ on which the image has been recorded on the second side is discharged from the carry-out passage 36 to the second stacker section 8 to complete the double-sided recording. During the above period, the second paper feeding section 6 is kept inactive.

(3) Multiple recording FIG. 5 is a block diagram for performing multiple recording.

Recording by the first image signal S ₄ given by the first image recording section 2 is also performed by the second image recording section 3.
and the second image signal applied to the same side of the paper
Record according to _S5 .

That is, first, in the first image recording section 2, the first
A paper P ₁ is supplied from the paper feed section 5 , a first image is recorded on one side (upper surface in the drawing) by a signal S ₄ , and the paper P 1 is delivered to the paper handling section 4 . In the paper handling section 4, the solenoid 405 is activated,
The received paper P ₁ is delivered as is to the second image recording section 3 from the carry-out passage 41. The transferred paper P ₁ is transferred to the transfer unit 34 with a second image based on the signal S ₅ of a different color, etc., but the surface to which the transfer is applied (the upper surface in the figure) is transferred by the first image recording unit 2. It is the same surface as the surface that was The paper P ₁ on which the second image has been recorded is discharged from the carry-out passage 36 to the second stacker section 8 to complete the multiplex recording.

As mentioned above, in such an image recording device,
It has the following characteristics. That is, (a) By providing a plurality of image recording units, it is possible to easily increase the speed of the device without causing various problems that occur when increasing the speed of a single device. Therefore, it is possible to stably and economically obtain an image recording apparatus having a speed exceeding the upper limit of conventional methods.

(b) Furthermore, by connecting the two image recording sections with a paper handling section, it can be used not only as a high-speed recording device but also as a double-sided recording device. In addition, when recording on both sides, unlike in the past, there is no need to start recording on the second side until the recording on the first side is completed; instead, the first image recording section continues recording on the first side. , the second image recording section can perform recording on the second side, making it possible to perform extremely efficient recording.

(c) Furthermore, it is possible to perform multiple recording continuously with the same device, and to perform a variety of image recordings such as color recording, thereby making it possible to obtain a highly functional image recording device with a variety of functions not previously available.

(d) Furthermore, by having the paper feed section and stacker section (sorter section) in one place even though there are multiple image recording sections, it is possible to improve the convenience of operation for the operator. , it has many features and is extremely useful.

As described above, this type of image recording device enables image recording with higher functionality than conventional ones, but when converting these devices into devices, there are problems inherent to this device. The following points can be raised. That is, (a) First, in the case of duplexing and multiplexing, a single sheet of paper passes through multiple image forming units;
Among the plurality of image forming units, it is necessary that the rotational state of the image developing body (hereinafter referred to as a photosensitive drum) be accurately aligned or synchronized with the conveyance of the paper. In the case of past image recording apparatuses, such as copying machines, a method of matching the rotation of the photosensitive drum and the conveyance of paper was to use a common drive source for the photosensitive drum and the paper conveyance section. However, in the case of this device, the paper transport parts are diverse and have long distances, so when a drive source is shared, many mechanical transmission means such as gears, chains, belts, etc. are used. As a result, speed fluctuations due to their mechanical precision tend to occur in each photoreceptor and the conveyance section. Therefore, it is currently difficult to maintain speed matching (matching of the rotation speed of the photoreceptor and the paper transport speed) within a desired accuracy range across each image forming section and the paper transport path. In addition, when common driving is used, for example, the impact or load fluctuation when the paper passes through the fixing device is directly transmitted to the photosensitive drum, causing image distortion. When the device is operated at high speeds,
When a certain sheet of paper passes through the fixing device, if the next image is being developed on the photosensitive drum, this development is likely to occur. In other words, in the case of this apparatus, if all the image forming sections, especially the photosensitive drum and the paper transport section, are driven in common, a new problem will occur.

(b) Second, this apparatus includes a laser scanner that rotates at high speed as an image forming means, and laser light is irradiated onto the generatrix of the photosensitive drum. A laser image formed by laser light must be formed on the photosensitive drum at the correct time without distortion and in accordance with the transport time of the paper. First, in order to obtain a distortion-free laser image, the rotation of the laser scanner and the rotation of the photoconductor must be synchronized with high precision, and the vertical and horizontal image forming speeds of the laser image (the rotation of the photoconductor must be It is necessary to match the scanning speed of the laser beam, that is, the rotation of the laser scanner (which affects the image forming speed in the lateral direction). However, in reality, the number of rotations of the laser scanner and the number of rotations of the photosensitive drum are so different that it is impossible to have the same driving source.
Therefore, each has a drive source with a signal generation source, for example a device that generates a signal every rotation.
It is equipped with a DC motor, and uses feedback to match the generated signal to either side, while controlling the drive source to achieve highly accurate synchronization. If a single device, like this device, has multiple photosensitive drums and laser scanners, using the conventional control method would require multiple rotation control circuits, which could be a factor in increasing the cost of the device itself. Become. In addition, in order to obtain a laser image on the photosensitive drum at the same time as the paper is transported, a single time planning section is provided in the device, and the rotational speed of the photosensitive drum and the paper transport speed are matched. It is necessary to determine the timing of laser image formation based on time measurement while checking the position of the paper being transported. In the conventional method, the photosensitive drum and paper transport section are commonly driven by a drive source with a signal generation source, the position of the paper at a certain time is detected, time is measured by counting the generated signals, and the laser image is It determined the period of formation. As mentioned above, it is difficult to standardize the drive of all the photosensitive drums and the transport section in this device, so it is possible to use a common drive for one photosensitive drum and the transport section, and to drive the remaining photosensitive drums separately. In this case, there will be a difference in the control generation signals between the photosensitive drums, which will cause problems for the main body control section (especially in the case of duplexing and multiplexing). Therefore, a new main body control section is required to control the entire main body.

As mentioned above, in the above-mentioned apparatus, there is a problem that the multiple photosensitive drums, paper transport section, and laser scanner section need to be driven in high precision and synchronization without affecting each other. The point was hot.

〔the purpose〕

The present invention has been made in view of the above-mentioned problems.In an image recording apparatus equipped with a main body control section having a single reference signal generation section, each of the plurality of image recording sections has its own rotation drive. The purpose of the present invention is to control each rotational output with high precision and at low cost by configuring this drive source group to be individually feedback-controlled with the reference signal generation section. .

〔Example〕

This embodiment will be described below based on the drawings.
FIG. 6 is a schematic diagram showing a drive control method when the present invention is implemented in the apparatus shown in FIG. 1. 1
01 is the first image recording section 2 and the second image recording section in FIG.
A drive source 201 drives the paper transport section, paper handling section 4, first paper feeding section 5, second paper feeding section 6, etc. of the image recording section 3, and a drive source 201 is the photosensitive drum 2 of the first image recording section 2.
221 is a drive source that drives the laser scanner 22 of the first image recording section 2;
301 is a drive source for driving the photosensitive drum 30 of the second image recording section 3; 321 is a drive source for driving the photosensitive drum 30 of the second image recording section 3;
This is a drive source that drives the laser scanner 32.
The drive source for each of the above is a DC motor. The reason for using a DC motor is when performing rotation synchronous control.
This is because relatively high precision control is possible by changing the input. 9 is a reference signal generator. A crystal oscillator (not shown) is used as a reference signal generating means. The reason for using a crystal oscillator is that it is relatively inexpensive (operating power source is easily available) and provides a highly accurate reference signal (oscillation error within several ppm). Note that the reference signal generating section 9 is in communication with the main body control section 91.

Next, the operation of drive control according to this embodiment will be explained. Normally, when the power is turned on, only the reference signal generating section 9 is operating, and a reference signal (hereinafter referred to as a pulse) is generated. Also,
Although the laser scanner motors 221 and 321 are also rotating, they are not receiving rotational control from the reference signal generating section 9. When a signal to start image recording is input, the photosensitive drum drive motors 201 and 3 in the image recording apparatus are activated.
01, the transport section drive motor 101 starts rotating and receives rotation control from the reference signal generation section 9 together with the laser scanner motors 221 and 321. The main body control section 91 counts several pulses from the time when the image recording start signal is input, and based on the counted pulses, the main body control section 91 controls each paper feeding section, laser modulation, and paper handling section by how many pulses. Operate the eye to record an image. Main body control section 91
Since this operates each image forming section and paper handling section, it is necessary not only to input a recording start signal but also to input information such as the type of recording to be performed. The number of pulses to be counted from the input of the image recording start signal depends on how long it takes for each motor to synchronize under rotational control (rise time), or the charging characteristic adjustment time of the photoreceptor (adjusted in advance). (setting the photosensitive characteristics).

FIG. 7 is a diagram showing signals of each part showing the state of the above-mentioned control. S ₁ is the image recording start signal,
P ₁ is the reference pulse at the start of main body operation. S ₁
Counting n ₁ pulses results in P ₁ , during which time each motor is synchronized. In the figure, + and - are
This shows the deviation from the synchronization state O. After counting n ₂ minutes from the pulse of P ₁ , the paper feed roller 5 of the first paper feed section
0 comes into contact with the paper and sends it to the first image recording section 2,
Laser modulation by counting n ₃ minutes from P ₁ pulse 29
to form a laser image on the photoreceptor. It goes without saying that how many times to count and activate each actuating section varies depending on the operating state of the device (high speed, multiplexing, duplexing, etc.). 7th
In the figure, an example is shown in which the laser scanner section is constantly rotated, but it may be normally stopped and started when _S1 is input.

[Other Examples]

FIG. 8 is a schematic diagram of another embodiment of the drive control method of the present invention. The difference from FIG. A part thereof has a reference signal generating section 9.
The other drive sources are controlled to be synchronized with the drive source 201 based on the pulses generated by the reference signal generator 9. The reference signal generating means includes a device at one end of the rotational output shaft that generates a pulse every time the rotational shaft rotates. The reason for using such means is that the reference signal generator 9
One example is that it requires a power source. The reference signal generating section 9 communicates with the main body control section 91, and uses the generated pulses for controlling the main body.

FIG. 9 is a diagram showing the signals of each part showing the state of this drive control, and is almost the same as the case of FIG. This occurs when the motor begins to rotate. It is necessary to drive the photosensitive drum 20 and count the pulses at the same time that the image recording start signal _S1 is input. The subsequent control of the main body is the same as that shown in FIG.

〔effect〕

As explained above, in the present invention,
Since each drive section of a high-performance image recording device that has multiple image recording sections in one device can be controlled without affecting each other, the rotational output of each section can be aligned and synchronized with high precision. This has the advantage that it is easy to implement and can be realized at low cost.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of an example of an image recording apparatus embodying the present invention, FIG. 2 is an internal configuration diagram of its paper handling section, and FIGS. 3 to 5 each illustrate the apparatus shown in FIG. 1. 6 is a schematic diagram of the case where the present invention is implemented in FIG. 1, and FIG. 7 is an explanatory diagram of the control method in FIG. FIG. 8 is a schematic diagram of another embodiment, and FIG. 9 is an explanatory diagram of the control method of FIG. 8. DESCRIPTION OF SYMBOLS 1... Image recording device main body, 2... First image recording section, 3... Second image recording section, 4... Paper handling section, 9... Reference signal generation section, 91... Main body control section, 101, 201, 221, 301, 321...
...Each drive source (motor), P ₁ ... Reference pulse at the start of main unit operation, S ₁ ... Image recording start signal.

[Claims]

1. In a printing device comprising a print data creation means for creating print data and a print control means for performing printing based on the print data transferred from the print data creation means, the print data creation means The print control means is configured to transfer print data when a print command is issued, and transfer a signal instructing reprint when a print command is issued for the second time or later, and when the print data is received, the print control means performs printing based on the print data. A printing device characterized in that the printing device is configured to print based on the printing data that has already been set when a signal instructing reprinting is received.