JPH0436765A - Image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an image forming apparatus such as an electrophotographic printer.

[Conventional technology]

Conventionally, this type of image forming apparatus has a configuration as shown in FIG. Each function will be explained below with reference to FIGS. 13 to 17.

1 is a photoreceptor drum which is an electrostatic latent image carrier; 2 is a semiconductor laser; 3 is a polygon scanner for scanning the light beam emitted from the semiconductor laser 2 on the photoreceptor drum 1;
4 is a charging roller that uniformly charges the photoreceptor drum l, 5
1 is a developing device that visualizes the electrostatic latent image formed by the light beam with toner; 6 is a transfer roller that transfers the developed toner image onto paper; 7 is a device that removes untransferred toner on the photoreceptor drum 1; 8 is a fixing roller that fuses the toner transferred to the paper, 9 is a paper feed roller that feeds paper, 10 is a paper cassette that loads paper, 11 is a roller that once hits the fed paper and stops it. A registration roller 12 is used to synchronize the start timing of light beam irradiation onto the photosensitive drum 1 with paper transport, and a paper presence/absence sensor 12 is used to check whether the paper is being transported reliably. FIG. 14 shows a control system for controlling the image forming apparatus having such a configuration.

Reference numeral 13 denotes an engine control section that controls the entire printer engine 20. The engine control unit 13 performs bidirectional communication with the printer controller 14 to receive commands from the printer controller 14 and also sends back the internal status of the printer engine 20 to the printer controller 14 . In addition to such communication, the engine control section 13 also receives print request signals, pre-feeding request signals, image data, and the like. 15
16 is an image control unit that controls the amount of laser light and drives/stops the polygon scanner 3 based on commands from the engine control unit 13 for parts that form light beams such as the semiconductor laser 2 and the polygon scanner 3; Drive of conveyance system such as paper feed roller 9, registration roller 11, fixing roller 8, etc.
A conveyance control section performs stopping and reading of the paper presence/absence sensor 12 based on commands from the engine control section 13.A transport control section 17 controls high voltages for charging, development, and transfer to predetermined values at predetermined timings according to commands from the engine control section 13. High pressure control unit that outputs, 1
Reference numeral 8 denotes an abnormality processing section that reads the internal state of the printer and notifies the engine control section 13 when an abnormality that interferes with normal print processing occurs.

Conventionally, this abnormality processing unit 18 handles abnormalities when the engine control unit 13 performs a printing operation in response to a print request signal from the printer controller 14, and performs paper conveyance in response to a prefeeding request. There was no distinction between processing for abnormalities when the system was in use, and a single processing was performed.

The paper cassette 10 will be pulled out and explained as an example below.

Upon receiving a print request from the printer controller 14,
The paper is conveyed to registration rollers 11 by driving the paper feed roller. At that point, a vertical synchronization request signal is output to the printer controller 14, and when the vertical synchronization signal is received from the printer controller 14, the image control unit 1
5, outputs an image data output command, and also starts a timer for measuring the paper feeding timing of the next page.

If there is no print request for the next page when this timer expires, the paper currently being printed is ejected and the conveyance system is stopped, and if there is a print request, the next page is commanded to be fed. . At this time, the presence or absence of a paper cassette is constantly checked, but in reality, the only abnormality processing that is performed is a process in which paper is stopped without feeding when a print request is received. In other words, when a pre-feeding request is received, pre-feeding is started, the paper is conveyed to a predetermined position, that is, the registration position, and the state waits for a print request.
At that point, if the cassette is removed and the cassette is removed, then the cassette is inserted again and a print request is received, the vertical synchronization request will not be output normally since the cassette is present at that point. , After receiving the vertical synchronization request, an image data output command is output.

[Problem that the invention is trying to solve]

However, in the conventional example described above, the paper out process when a print request is received and the paper out process when a prefeeding request is received are the same. Therefore, if the paper cassette is pulled out and reinstalled while it is being fed and waiting for a print request, even if the pre-fed paper has been pulled out, Even if the paper is not pulled out, even if it is not in a normal state, when it receives a print request it outputs a vertical synchronization request as usual, and when it receives a vertical synchronization signal it starts outputting image data. Put it away.

Therefore, the transfer roller directly transfers the toner image onto the roller, which may cause stains on the back of the image during the next printing. There was a drawback that the output was output.

[Means and operations for solving the problem] According to the present invention, a processing section when an abnormality occurs during a printing operation due to a normal printing request, and a processing section that separately performs the following processing during prefeeding due to a prefeeding request. By newly providing a processing section for handling anomalies that occur between receiving a print request and performing vertical synchronization, the problems that have conventionally occurred can be solved and the print quality of the image forming apparatus can be improved.

〔Example〕

In this embodiment, an example will be described in which different processing is performed before and after a print request regarding abnormality processing when a paper cassette is pulled out after receiving a paper pre-feeding request.

The configuration of the image forming apparatus of this embodiment is a conventional example (FIG. 13).
The detailed explanation will be omitted here. Further, the control system of the image forming apparatus of this embodiment has a configuration as shown in FIG.

The engine control unit 100 sends and receives commands/status to and from the old printer controller 1, sends and receives vertical synchronization requests/vertical synchronization signals, receives image data, and outputs horizontal synchronization signals, and also controls each part of the engine as shown below. is under control. The image control section 102 drives/stops the semiconductor laser and the polygon scanner based on commands from the engine control section 100. The conveyance control unit 103 drives/drives registration rollers for sheet conveyance and vertical synchronization.
When the engine control unit 100 receives a request for pre-feeding, it also performs pre-feeding based on a command from the engine control unit 100. The high voltage control unit 104 outputs high voltages of predetermined values at timings when the engine control unit 100 commands high voltages for charging, development, and transfer.

The error processing unit 105 processes abnormalities that occur during standby and printing when a print request is received, and the error processing unit 106 transports paper to a predetermined position after receiving a paper prefeed request. This process is different from the content of the abnormality processing unit 105 because it performs processing for an abnormality that occurs after the print request is received and the vertical synchronization signal is received after the print request is stopped. The actual control will be shown using the flowcharts in FIGS. 2 and 3.

FIG. 2 is a processing flowchart when a normal printing request is received. First, a check is made to see if a print request has been received (step SL), and if not, a check is made to see if a pre-feed request has been received as shown in FIG. 3 (step S2). Upon receiving the print request, the control task of the abnormality processing unit 105 is activated (step S3). Abnormality processing unit 10
In task 5, as shown in FIG. 4(1), the presence or absence of a cassette is checked (step 535) and the presence of paper (step 836). If there is no paper, a process is performed to set a paper out flag (step 537).
). Furthermore, if the cassette is installed and there is paper, the paper out flag is reset (step 53).
8). If the paper out flag is set by such processing, steps S4 to S in FIG.
5, if first printing is in progress, check whether printing of the previous page has been completed (step S6), and if it has been completed, paper conveyance is stopped (step S7). If the previous page is being printed, the abnormality processing task A is activated again. Further, in step S5, if the first printing is not in progress, the abnormality processing A task is activated again in the same manner.

If the paper out flag is being reset in step S4, the scanner and high voltage are turned on to start paper feeding operation (steps S8 and S9). After feeding the paper, a predetermined time T1 (se
c) When the time has elapsed (Step 5IO1Sll), stop the paper feed roller and output a vertical synchronization request to the controller (Step 513), and if the vertical synchronization signal is received (Step 514), command the start of outputting image data. At the same time (step 515), a timer T2 (see) that controls the paper feeding timing of the next page is set. This T
When 2 (see) has elapsed, checking for the next print request is started again (step S16.517).

If a pre-feeding request is received before a printing request is received (3rd
In step 521), the abnormality processing task B is first activated (step 522). As shown in FIG. 4, the abnormality processing task B sets a paper out flag depending on the presence or absence of a cassette and the presence or absence of paper (step S44, 545) if the prefeed end flag is not set (step 541). Alternatively, it is to be reset (step S46.
547). Therefore, if the paper out flag is set at this point, the process moves from step S23 to step S24 in FIG. It is selected whether to stop paper conveyance or to perform abnormality processing task B again (step 525).

In step 323, if the paper out flag is not set, the paper feed roller is driven.
7), time T3 (se
c) When the elapsed time has elapsed (step 328, $29), stop the paper feed roller (step 530), set the pre-feed end flag (step 531), and drive the abnormality processing task B. At this point, the abnormality processing task B moves from step 34.1 to step S42 in FIG.
Step 543), if there is a cassette, return to normal processing.

Then, while waiting for the print request to be received, the abnormality processing task B is continued to be started, and when the print request is received, the prefeeding end flag is reset (step 534), and the process returns to step S13 in FIG. 2 via ■. return.

According to this process, when performing normal printing without pre-feeding paper, even if the cassette is pulled out, there will be no paper left.
It only maintains the standby state without feeding paper, but
If the cassette is pulled out while the cassette is stopped waiting for a print request after pre-feeding and transporting the paper to a predetermined position, it will be treated as a jam occurrence.

As explained above, in this embodiment, when an abnormality occurs while executing the operation mode shown in FIG. 2, the abnormality processing task A shown in FIG. 4 (1) is executed, and the third If an abnormality occurs while executing the operation mode shown in the figure, the abnormality processing task B shown in FIG. 4(2) is executed. Therefore, appropriate abnormality processing can be performed depending on the operation mode.

Moreover, when the cassette is pulled out, the paper stopped at the registration roller position by the pre-feeding operation often becomes misaligned, the paper is pulled out, and the trailing edge is torn. In this embodiment, when the cassette is pulled out in the abnormality processing task B, the jam processing is performed, that is, the paper that has accumulated in the machine is ejected, and the paper is fed from the paper feed cassette again. Problems such as back staining in the next printing due to positional deviation etc. are solved.

[Other Examples]

5 to 8 are diagrams showing a second embodiment of the present invention.

FIG. 5 shows the device configuration in the second embodiment.

200 is a photosensitive drum, 201 is a semiconductor laser, 202
is a polygon scanner, 203 is a charging roller, 204 is a developer, 205 is a transfer roller, 206 is a cleaner, 207
is a fixing device, 208 is a first paper feed roller, 209 is a second paper feed roller, 210 is a paper feed tray, 211 is a paper cassette,
212 is a registration roller, and 213 and 214 are paper presence/absence detection sensors.

The device configuration differs from the first embodiment described above in that paper can be fed from a paper feed tray, and a paper presence/absence sensor 213 is added in front of the registration roller 212. In this embodiment, the process when the pre-fed paper is pulled out by a user or the like before a printing request is received will be described in this embodiment. The control system is the same as that shown in FIG. 1 described in the first embodiment.

Next, the conveying operation in the printer shown in FIG. 5 will be explained.

When a printing request is received in step E1, data representing the paper feed port specified by the controller among the first or second paper feed rollers 208 and 209 is read (step E2), and an abnormality processing task described later is performed. A is executed (step E3), and the paper feed roller of the designated paper feed port is driven (steps E5, E6). After that, the paper presence sensor 21
3 detects the paper (step E7), and if a predetermined time T has elapsed after the detection (steps E8, E9)
, the paper feed roller is stopped (step EIO), and a vertical synchronization request is output to the controller (step ELL).

Next, when the vertical synchronization signal is received, the process proceeds from step E12 to step E13, where the registration roller 212 is driven and image writing onto the photoreceptor drum 200 is started. After the predetermined period T5 has elapsed (step E14)
, E15), when the image writing is completed, the process returns to "start".

The abnormality processing task A in step E3 mentioned above is the eighth
As shown in FIG.
This is exactly the same as the example.

If a pre-feeding request is received before a printing request is received, the process advances from step E21 in FIG. 7 to step E22, and the designated paper feeding roller is driven (step E22).
~E25). Thereafter, wait for the paper presence/absence sensor 213 to detect paper (step E26), and wait for a predetermined time T after the detection.
After 4 elapses (steps E27, E28), the paper feed roller is stopped (step E29).

Then, it enters a state of waiting for a print request (step E30).
When a print request is received, it passes through an abnormality processing task B, which will be described later (step E31), and if normal, outputs a vertical synchronization request to the controller (step E33).

Next, when a vertical synchronization signal is received (step E34), the registration roller 212 is driven and image writing to the photosensitive drum 200 is started (step E35).
. After the predetermined period T5 has passed (steps E36 and E37)
), return to “Start” until image writing is completed.

As shown in FIG. 7, after receiving a foster paper feed request and transporting the paper to the registration roller position, the paper feed roller is stopped and a print request is waited for, but a print request is received in step E30. Then, the abnormality processing task B shown in FIG. 8(2) is activated. Abnormality processing task B is “Yes” depending on the presence or absence of paper in the registration sensor (step E41)
If so, reset the prefeed reset flag in step E4.
2) If "absent", a pre-feed reset flag is set (step E43). After the pre-feeding is completed, the pre-feeding reset flag is read when a printing request is received, and if it is "l", it is determined that the pre-feeding paper has been removed.Step E32) The process returns to step E2 again via the diagram and FIG.

In this embodiment, it is possible to perform appropriate abnormality processing depending on the operation mode, and when the paper that has been pre-fed and stopped at the position of the sensor 213 is pulled out, the paper can be re-fed from the paper feed tray. Paper can be done and normal operation can be done if it is not pulled out.

[Third example] FIG. 9 shows an apparatus configuration in a third embodiment of the present invention.

Here, the paper cassettes are arranged in two stages, and the paper paths from each paper feed port to the registration rollers are structured so that they do not interfere with each other.

That is, as shown in FIG. 9, in this embodiment, in addition to the paper feed roller 9 and the cassette 10, there is also a paper feed roller 9a.

A cassette 10a is provided.

The processing in each operation mode of such a configuration is completely the same as the processing in the first embodiment shown in FIGS. 2 and 3, and the processing in the abnormality processing task A is as follows.
This process is similar to the process in the second embodiment shown in FIG. 1. Furthermore, as shown in FIG. 10, the processing in abnormality processing task B is similar to the first one, except that in each judgment step, it is determined whether the designated cassette is installed or not, and whether there is paper or not is determined for the designated cassette. This is exactly the same as the example.

In this embodiment, a paper pre-feed request is received, paper is pre-feeded from the paper feed port specified at that time, and the cassette is pulled out while the paper is stopped at the registration roller position. In some cases, jam clearance is performed only when the cassette of the paper feed slot that has been pre-fed is removed, and jam clearance is not performed when a cassette that is different from the paper feed slot that has been pre-fed is removed. This can prevent unnecessary jams from occurring.

However, in the configuration shown in Figure 11, if the cassette is pulled out in the direction of the arrow in the figure, it will be affected by another paper feed slot, so in this case, even if either cassette is pulled out, a jam will occur. Needless to say, it is desirable to do so.

[Fourth Embodiment] FIG. 12 is a flowchart showing the operation regarding pre-feeding of paper in a fourth embodiment of the present invention. In this embodiment, the operation when a print request is received before a pre-feeding request is received is the same as in the first embodiment (FIG. 2). Also, regarding the abnormality processing tasks A and B, the first embodiment (Fig. 4 (1), 4
This is the same as in FIG. (2)), and here we will explain the case where a pre-feeding request is received before a printing request is received.

In the embodiment described above, when the printer receives a print request while on standby, it drives the stopped scanner motor,
Paper feeding starts after the scanner motor reaches a specified number of rotations, but in this embodiment, if the printer receives a prefeeding request while it is on standby (step Ql), the scanner motor remains stopped and feeds the paper to the registration roller position. Convey (steps 03 to Q6).

After receiving the subsequent printing request (step Q7)
, starts driving the scanner motor (step Q8), and starts abnormality processing task B (step Q9).

After the scanner motor reaches the specified rotation speed (step Q)
10), outputs a numerical synchronization request (step Q13), receives a vertical synchronization signal (step Q14), and starts image writing (step Q15).

Even if the scanner motor is driven after receiving a print request after pre-feeding paper, if the specified rotation cannot be reached due to a scanner motor failure, it will be impossible to print, so if the normal abnormality processing is continued, the scanner motor will not be able to print. The fed paper can no longer be ejected forever. Therefore, in this embodiment, if a printing request is received after prefeeding paper and the scanner motor is driven, but the scanner motor does not reach the specified rotation within a predetermined time, the process moves from step QIO to step Qll, and a failure flag is flagged. If is set, the pre-fed paper is forcibly ejected regardless of instructions from the controller (step Q12). This can prevent paper from remaining unnecessarily in the printer.

〔Effect of the invention〕

As explained above, the processing for abnormalities that occur between the time when paper is pre-feeded and the end of vertical synchronization for that paper is different from the processing for abnormalities that occur when a normal print request is received. By providing a control means, it is possible to take appropriate measures against failures such as pulling out the cassette and failure of the scanner during paper pre-feeding, which greatly contributes to improving the quality of the printer.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the control system of the first embodiment of the present invention, and Fig. 2 shows the operation in the first embodiment when a printing request is received without receiving a prefeeding request. 3 is a flowchart for explaining the operation when a prefeeding request is received in the first embodiment, and FIG. 4 is a flowchart for explaining the abnormality processing task A of the first embodiment. FIG. 5 is a diagram showing the device configuration in the second embodiment of the present invention, and FIG. 6 is a flowchart for explaining the operation in B. FIG. 7 is a flowchart for explaining the operation when a pre-feeding request is received in the second embodiment. FIG. 8 is a flowchart for explaining the operation when a pre-feeding request is received in the second embodiment. A flowchart for explaining the operations in the abnormality processing tasks A and B, FIG. 9 is a diagram showing the device configuration of the third embodiment of the present invention, and FIG. 10 is the operation in the abnormality processing task B in the third embodiment. 11 is a diagram showing the device configuration of a modification of the third embodiment, and FIG. 12 is a flowchart for explaining the operation when a pre-feeding request is received in the fourth embodiment of the present invention. Flowchart for explanation; FIG. 13 is a diagram showing the configuration of a general image forming apparatus (laser printer); FIG. 14 is a block diagram showing the configuration of a control system of a conventional image forming apparatus; FIGS. FIG. 17 is a flowchart for explaining the operation of the prior art.

Claims (3)

[Claims] (1) An electrostatic latent image is formed on an electrostatic latent image carrier by irradiating a flashing light beam based on the image data, is developed with toner, and then transferred and fixed onto a specified sheet of paper to form a printed image. In an image forming apparatus that obtains a a conveyance control means for controlling the conveyance of paper; and prior to the print request, after the external device feeds the paper to the image forming apparatus from a first predetermined position,
By receiving a request from an external device to transport the paper to the second predetermined position and stop it (hereinafter referred to as a prefeeding request), the paper is fed from the first predetermined position and the paper is stopped at the second predetermined position. After transporting the paper to the predetermined position in step 2, stop the paper,
A paper pre-feeding control means that performs control until the printer enters a state of waiting for a print request from an external device; and a period from receiving the print request from the external device to feeding the paper, printing, and finishing discharging the paper. a first abnormality processing means that operates when an abnormality that affects printing processing occurs in the image forming apparatus; It is transported to a predetermined position and stopped.
An image forming apparatus comprising: a second abnormality processing means that operates in response to an abnormality that occurs until the next printing request is received. (2) a paper feeding unit that feeds the recording paper to a predetermined position and stops it; an image forming unit that forms an image on the recording paper based on external image data; a conveying means for conveying the recording paper to the image forming means; and a detection means for detecting an abnormal state related to the recording paper to be stopped at the predetermined position, An image forming apparatus is characterized in that the image forming apparatus performs processing different from processing for other abnormal states. (3) In an image forming apparatus having an image forming means for forming an image on recording paper based on image data from the outside, the recording paper is moved from a first predetermined position to form the image based on a print request signal from the outside. The first step is to feed paper to a means to form an image.
The recording paper is fed in advance from a first predetermined position to a second predetermined position, and the recording paper to be stopped at the second predetermined position is fed to the second predetermined position based on an external print request signal. and a second operation mode in which the image is formed by transporting the image from a predetermined position to the image forming means, and when an abnormality occurs during execution of the first or second operation mode, the operation mode An image forming apparatus characterized in that the image forming apparatus performs processing according to.