JPH0542353B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording apparatus in which a plurality of image forming apparatuses are provided and these are organically combined with a paper feeder, a stacker apparatus, and the like.

As is well known, various printers are used as output devices for computer systems. In the category of such printers, printers such as mechanical serial printers and mechanical line printers have been commonly used in the past. However, these printers have problems such as slow recording speed and noise generation, and in recent years, there is a tendency to replace them with non-impact printers. Mechanical line printers are being replaced by page printers (hereinafter referred to as electrophotographic printers) that make full use of electrophotographic technology such as laser printers or similar technologies.

In such electrophotographic printers, image fluctuations occur due to changes in the photoreceptor or developer over time or changes in the environment, or the function of the cleaning mechanism deteriorates over time due to wear of the cleaning blade or dirt on the fur brush. The points that occur, and furthermore,
These printers have problems such as deterioration of image quality, such as deterioration of transfer performance in the transfer process due to environmental changes, and the reliability of such printers has become a concern. Furthermore, in page printers, problems such as poor separation in the transfer section and wrapping of the recording paper in the fixing device occur, making it difficult for operators operating such printers to deal with these problems, resulting in paper jams, etc. In some cases, printer equipment may be out of operation for a long period of time.

Although it has many advantages over the mechanical printers mentioned at the beginning, such as rapid image formation and no noise, there are some printers that suffer from the reliability problems mentioned above, for example. When introduced into an output device of a computer system, the printer may stop operating due to deterioration in image quality or paper jam, and this will have a large impact on the entire computer system.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording device that is designed in view of the above points and is highly reliable as a system.

Regarding the present invention, in the category of electrophotographic printers, there are so-called page printers using cut paper, and furthermore, the multi-stacker shared printer proposed earlier in Japanese Patent Application Laid-open No. 157757/1983. is applied and described below. Now, in such printers, the way to obtain high reliability as a whole system is to improve the technology of the printer equipment itself, but since these points are not satisfied at present, it is necessary to use multiple printers arbitrarily. It would be more practical to systemize it so that it can be used selectively.

That is, for example, if you have two printers in your system,
Even if the probability of each printer going down is not sufficiently low, the probability of two printers going down at the same time is so low that it can be ignored.
When one printer goes down, if you repair and restore the first printer before the other printer goes down, the printing speed will drop by half, but the system as a whole will stop functioning. There is no. Note that "down" here includes deterioration in image quality, paper jams, and other random failures.

For shared printers, for example, 4
Since a plurality of workstations, such as 1 to 64 printers, are shared, the failure of such a printer affects the entire workstation system. According to this way of thinking, the number of printers in a system would be at least two, which would increase the system cost in a system that is not very large or a distributed system.

Therefore, once again, we examine the causes of printer failures. As mentioned above, the causes are concentrated in the image forming apparatus and the fixing apparatus, especially in the image forming apparatus. Therefore, it is more efficient to configure a printer with, for example, two image forming apparatuses than to use two printers independently. Regarding devices other than image forming devices and fixing devices, such as control devices and stacker devices including interfaces, character generators, system controllers, etc., these devices themselves
Since the cost is high, it is more advantageous in terms of cost to share such a device with an image forming apparatus or the like.

In view of the above points, the first feature of the recording device of the present invention is that it has a plurality of image forming devices (hereinafter referred to as IM devices for convenience) for recording images, and normally all IM devices are used. If you use the IM device to print out at high speed and one of the IM devices goes down, stop using that IM device,
It consists in using only other IM devices. As a result, there is no problem with the print function other than a decrease in printout speed, and it is only necessary to repair and restore the downed IM device before all the IM devices go down. By the way, what an operator is most impressed with is not the printer itself, but the stacker where the recording paper is stacked, and whether or not what he or she needs is printed out there. That is,
It does not matter which IM device prints out, but which stacker the desired printout was sent to. In the recording device of the present invention
Even if one of your IM devices goes down, you can still go to the stacker and get the printout you want.

In a printer that has multiple IM devices, that is, a recording device, the paper feeding device, IM device, stacker device, etc. must be functionally related to each other in order to convey the recording paper, unless a transportation system is established. cannot perform its functions efficiently.

The conveyance system will be conceptually explained below using FIG. 1. Here, the conditions in such a conveyance system shall be defined as follows.

Recording paper conveyance pitch; l′p=lp+lg IM device conveyance speed; Vm Paper feed conveyance speed; Vi Output conveyance speed; Vo Here, lp is the recording paper length, and lg is the distance between recording sheets, that is, the trailing edge of the recording paper. is the distance from the leading edge of the next recording paper. Note that the paper feed conveyance speed Vi is an average speed including a temporary stop for registration adjustment in front of the IM device. Furthermore, depending on the printer specifications, the recording paper length lp and
The IM device transport speed Vm is determined as appropriate, and
From general technical knowledge, the recording paper distance lg is approximately 25 m/
Therefore, the recording paper conveyance pitch l'p is determined by the recording paper length lp. Then, from these relationships, the paper feed conveyance speed Vi and the paper discharge conveyance speed Vo after the IM device may be determined, respectively.

FIG. 1A shows an example in which each stage has an independent paper feeding device 1, and there are two paper feeding devices 1,
Independently provided and compatible with each paper feed device
Recording paper is fed to the IM device 2, respectively. Diagram B
has two sets of independent paper feeding devices 1 with unequal distances to the recording paper confluence point _C1 , and an IM device 2.
This shows an example in which the distance from C2 to the next confluence point _C2 is unequal. As in the two examples shown in Figures A and B, when the paper feed device is independent, the paper feed conveyance speed Vi,
This is approximately equal to the recording paper conveyance speed Vm in the IM device. That is, as follows.

ViVm _FIG . This shows an example in which the distances of the recording paper paths from the branching point B toward the end of the image formation to the confluence point _C2 after image formation are equal. Hereinafter, the path from B to _C2 will be referred to as the IM device path.

Figure 1D shows a case where the IM devices 2 have two paper feed devices 1 common to each IM device 2, which are equidistant to the confluence point _C1 , and the IM device paths from B to _C2 are equal to each other. This is an example.

FIG. 1E shows an example in which two common paper feeders 1 are provided at unequal distances to the confluence point _C1 , and the IM device paths from B to _C2 have unequal lengths.

Regarding the paper feeding conveyance speed Vi, in the case of the examples shown in FIGS. 1C to E, since each paper feeding device 1 is commonly used for each IM device 2, the speed Vi is as follows.

Vi2m In the examples shown in Fig. 1 C to E, when recording sheets are alternately fed from multiple common recording devices, if each recording sheet length lp is equal, the timing at which they reach the confluence point C ₁ is set at equal intervals. do.

In addition, in the examples shown in FIGS. 1B and E, if the distances to the confluence point _C1 are not equal, the paper feeding timing of the paper feeding device with the shorter distance is adjusted based on the difference in distance and the paper feeding speed. Time τ derived from the relationship
only delay.

Next, to explain the first speed conversion area,
As shown in FIGS. 1C to 1E, this area is provided in the recording paper path from the branch point B to the IM device 2, and is designated by reference numeral _R1 . And this area
In _R1 , the speed is decelerated from Vi to Vm, and this area needs to be longer than the recording paper length lp.

Next, to explain the second speed conversion area,
This area is provided in the recording paper path from the IM device 2 to the confluence point _C2 , as shown in FIGS.
It is designated by the symbol _R2 . Then, in this region _R2 , the speed is increased from Vm to Vo, and this region needs to be longer than the recording paper length lp.

Regarding the IM device path from branch point B to confluence point _C2 , it is desirable to make the two path lengths equal in terms of recording paper conveyance control, as shown in the examples shown in FIG. 1 C and D. If the two paths have unequal lengths, as in the example shown in FIG.

By the way, printers generally use recording paper of different sizes, but in this case, the paper feeding timing is changed depending on the size of the recording paper, and when using small-sized recording paper, the recording time is shortened. There are advantages to being able to do so. However,
According to this method, in the example shown in FIG. 1E, the path length difference must be changed depending on the recording paper size. Therefore, instead of this, as shown in _FIG . be. For example, if a certain size of recording paper is standard,
When using a longer recording paper than this, the recording paper is temporarily stopped in the registration area of the longer route among each route from the IM device 2 to the confluence point _C2 , and when using a shorter recording paper than the standard, The recording paper may be temporarily stopped on the shorter path, and the recording speed will not be reduced due to this.

In addition, the paper discharge conveyance speed Vo is set to be approximately equal to the paper feed conveyance speed Vi. When conveying the recording paper, since the recording paper distance lg is provided as described above, Vi and Vm do not need to be exactly equal, but may be approximately equal. In addition, when conveying recording paper of different sizes to two IM device paths, it is sufficient to set both the paper feeding timing and the registration area, and to temporarily stop the recording paper. There will be no reduction in recording speed due to this.

Next, a specific embodiment of the recording apparatus of the present invention will be described. In the recording apparatus of this embodiment,
Japanese Patent Application Laid-Open No. 55-84955 as an image forming device (IM device)
The LIST method described in the publication, and
A multi-stacker was used as a fixing device for fixing the image on the recording paper after image formation, and as a stacker device.

The recording apparatus shown in FIG. 2 includes a paper feeding device 1 with two independent stages, and a stacker device 4 having eight stackers. The rotational speed (Vi) of the paper feed roller 1a and the pair of transport rollers _r1 , _r4 for feeding the recording paper one by one is approximately equal to the recording paper transport speed (Vm) in the IM device 2, Further, the IM device 2 and the fixing device 3 transport the recording paper at an IM device transport speed Vm. Note that the IM device 2 includes a driver 2a for generating a pattern signal, and supplies toner to recording paper to form a pattern image.

The rollers r ₂ , r ₃ , and r ₅ are located in the second speed conversion area described above, and can take two speeds, Vm and Vo. Further, the rollers r ₆ , r ₇ , r ₈ and the paper discharge roller 5 transport the recording paper under the condition of Vi2Vm.

The recording apparatus shown in FIG. 3 is an improved example of the recording apparatus shown in FIG. This recording device has paper feeding devices 1 that are independent of each other in each stage, and each of the paper feeding devices normally operates independently as shown in FIG. One IM in
If device 2 goes down, the paper feeding device that was previously feeding paper to this IM device will now feed paper to the other IM device, and both paper feeding devices will replace each other. This allows it to be used effectively.

The example recording apparatus shown in FIG. 4 includes a four-stage paper feeder 1 common to both of the two IM devices 2, and a stacker device 4 having an eight-stage stacker. Paper feed roller 1a and roller r ₁ are Vi
The recording paper is conveyed under the condition of 2Vm, and the rollers r ₂ , r ₆ , r ₇
are respectively located in the first velocity conversion region mentioned above, and can take two velocities, Vi and Vm. IM device 2
and fixing device 3 transport the recording paper at a speed of Vm, rollers r ₅ and r ₈ are respectively located in the second speed conversion area, and rollers r ₉ , r ₁₀ , r ₁₁ and paper ejection roller 5 are transported at a speed of Vo2Vm. Convey the recording paper according to the conditions.

In the embodiment shown in FIGS. 2 and 3,
When using two IM devices 2 at the same time to perform a series of printouts at high speed using recording paper of the same size, it is necessary to set recording paper of the same size in each of the upper and lower paper feed devices 1. .
On the other hand, in the embodiment shown in FIG. 4, it is not necessary to set recording paper of the same size in each paper feeder 1, and it is not necessary to set recording paper of the same size continuously from one specific paper feeder. Just feed the paper.

The embodiment shown in _{FIG .}
The lengths of the two IM device paths up to this point are equal to each other, so there is no need to provide a registration area of the recording paper between them. In the figure, the path indicated by the broken line is the path for printing out both sides, and the rollers installed in this path
_r3 achieves the function of changing the conveyance direction of the recording paper. And such roller r ₃ and the other roller r ₄ are
The recording paper is conveyed at a speed of Vm. In this recording device capable of double-sided printing, the IM device 2 is
Moreover, since these methods are used simultaneously, the recording paper conveyance path can be further simplified.

The recording apparatus shown in FIG. 5 includes a three-stage paper feeding device 1 common to both of the two IM devices 2, and a stacker device 4 having a four-stage stacker. Paper feed roller 1a and roller _r1 are Vi
The recording paper is conveyed under the condition of 2Vm, and the rollers r ₂ , r ₄ , r ₅
is located in the first velocity conversion region and can take two velocities, Vi and Vm. IM device 2 and fixing device 3
The recording paper is conveyed at a speed of Vm, while the roller
r ₃ , r ₆ , r ₇ are located in the second speed conversion region, respectively,
A registration area of the recording paper is provided in this area.
On the other hand, rollers r ₈ , r ₉ and paper ejection roller 5 are Vo
Convey the recording paper under the condition of 2Vm.

The recording device shown in _FIG .
The two IM device paths up to _r8 have unequal lengths, which makes it possible to shorten the conveyance path length, thereby increasing the reliability of recording paper conveyance and making the device itself more compact. I can do it. In FIG. 5, the reference numeral 6 indicates an interface, the reference numeral 7 indicates a page memory character generator, and the reference numeral 8 indicates a system controller. , a stacker device, etc. are housed in a housing 10 of the recording apparatus as shown in FIG. 6, and various operations of the recording apparatus are performed through a control panel 9.

Next, the failure of the IM device will be described by applying the embodiment shown in FIG. 5. Regarding the failure of the IM device, it can be classified into three categories as listed below.

(1) Degradation due to image quality Image quality changes slowly, such as image density or background dirt, so if the operator determines that there is an abnormality in image quality during this process, the control panel 9 (see Figure 9) ) to generate, for example, a test pattern.
Using this test pattern, it is possible to detect the degree of deterioration in image quality, and also to determine the degree of deterioration in image quality.
Determine whether the problem has occurred with the IM device, and based on this, disconnect the downed IM device from other IM devices and continue image recording with the other IM device.

The above method is a manual method in which the operator visually observes the image density, etc., and stops the function of the downed IM device based on the results.
As shown in Figure 5, the image density detection sensor DS
The IM device may be provided directly after the fixing device 3, and the image density may be optically and automatically detected by this sensor, and the function of the IM device may be stopped based on the detection result. In this case, if the detection area of the sensor is made sufficiently small and arranged at a predetermined pitch in the recording direction of the recording paper, there is a sufficient probability that the image will fill that detection area, and the detection timing is Since this can be recognized in advance by the system controller, abnormalities in the image density of the recording paper can be correctly detected using the measured optical density when the image is supposed to fill the detection area. can.

In this way, when an abnormality is detected,
Automatically disconnecting an IM device from other IM devices while simultaneously sending a message to a predetermined or arbitrary workstation that says "IM device disconnected." An operator who recognizes such a message either directly performs the work to restore image deterioration by himself or requests a full-time maintenance person to perform the restoration. Note that even if each IM device detects the remaining amount of toner and outputs a signal requesting toner replenishment, the toner is not replenished, resulting in a toner shortage. The IM device is separated from other IM devices.

(2) Down due to paper jam Generally, a recording paper detection sensor is provided along the recording paper conveyance path to detect a paper jam, but in the embodiment shown in FIG.
As shown in , a paper detection sensor is installed at an appropriate location on the paper transport path, and the sensors PS in the two IM device paths can detect in which path a paper jam has occurred, and The IM device in the path where the paper jam occurred is separated from other IM devices, and a message to this effect is sent to the workstation.

(3) Downtime due to failure The IM device goes down due to mechanical failure or electrical failure, which causes the paper to stop being conveyed or the image quality to become abnormal.In such cases, the IM device goes down. The processes described in (1) and (2) are performed, and abnormal mechanical vibrations, control errors, etc. are processed by a more advanced self-diagnosis system. In any case, at the same time as disconnecting the downed IM device,
There is no difference in sending a message to this effect to the workstation.

In this way, the recording device of the present invention basically has the following features:
It has at least a paper feeding device, an image forming device, a stacker device, and a control device, the image forming device of which forms a visible image on each of the plurality of sheets of recording paper fed, For example, when such a recording device is used as an output device of a computer system, even if one of the image forming devices goes down, the other image forming devices will not be affected. Its operation can be continued without the risk of causing major damage to the entire system. Further, it is possible to restore a downed image forming apparatus or the like without stopping the system system.

The above control device sets the paper feeding timing in the paper feeding device, controls the start and stop of recording operation in the image forming device, or controls the loading of recording paper into each bin of the stacker device. control the selection of In addition, the recording apparatus of each of the above-mentioned embodiments uses a LIST type image forming apparatus, which requires a fixing device. When using the above, a fixing device is not required.

As described above, the recording apparatus of the present invention is equipped with a plurality of image forming apparatuses that are organically combined with a paper feeder and a stacker apparatus. Even if the function is stopped due to a clog or a mechanical failure, the image forming function can be continued by another image forming apparatus, and during this time, the image forming apparatus that has stopped functioning can be restored. The desired recording paper printed out by the stacker device can be continuously obtained, and recording can be performed as quickly as possible during normal operation.

[Brief explanation of the drawing]

1A to 1E are diagrams showing respective examples of the recording paper conveyance system in the recording apparatus of the present invention, and FIG.
5 to 5 are configuration diagrams showing different embodiments of the recording apparatus of the present invention, and FIG. 6 is an external perspective view of the recording apparatus shown in FIG. 5. 1... Paper feeding device, 2... Image forming device, 4...
Stacker device, B...branch point, _C1 , _C2 ...merging point, _R1 ...first speed conversion area, _R2 ...second speed conversion area, _R'2 ...resist area.

Claims (1)

[Scope of Claims] 1. A plurality of paper feeding devices, and a plurality of image forming devices that respectively correspond to the paper feeding devices and form visible images on recording paper fed from the paper feeding devices. , a common stacker device that stacks each recording paper after image formation discharged from the plurality of image forming apparatuses, and a common stacker device that feeds the recording paper from each of the paper feeding devices to each of the image forming apparatuses, A confluence point where the paper feed paths from each of the paper feed devices join together, a common conveyance path that feeds the recording paper from this confluence point, and a branch from this common conveyance path that branches to each of the above image forming devices. a plurality of paper feed paths each comprising a plurality of paper feed paths for feeding the recording paper in a single manner; It has a sheet discharge path having a confluence point for feeding and guiding the feed to a common stacker device, and a control device that controls the operation of each of the above devices, and controls the conveyance speed of the sheet feed path to the confluence point of the image forming device. The transport speed is set higher than the transport speed, and the transport speed is branched from the common transport path to reduce the transport speed to each of the image forming apparatuses to the transport speed of the image forming apparatus. A recording apparatus characterized in that the conveyance speed of a conveyance path from the apparatus to a common stacker device is increased higher than the conveyance speed of the image forming apparatus. 2. The recording apparatus according to claim 1, wherein a registration area is provided in the paper ejection path.