JPH0454997Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a printer that uses continuous paper with perforations, and the present invention uses perforations to detect conveyance abnormalities such as skewing and meandering of the continuous paper. The present invention relates to a conveyance trouble detection device for continuous paper with attached paper.

(Prior Art) Conventionally, a photoconductor on the surface of a photoconductor drum is exposed to light to form a latent image, toner is attached to this latent image and developed, and the toner is transferred to recording paper and fixed by a fixing device. Image forming apparatuses that utilize so-called electrophotography are mainly used in copying machines, but recently they are also being used in printers that print out computer output. .

In copying machines, the recording paper is cut paper (single-sheet paper).
Although it is common to use a hot roll fixing method to fix images, it is desired that printers use the same continuous recording paper as that used in conventional line printers.

The continuous recording paper that is the same as conventional paper is so-called fan-fold paper, which is folded continuous paper with perforations (hereinafter simply referred to as continuous paper), and the folded part forms a perforation so that it can be easily cut. It is something that exists.

Fixing methods include so-called heat roll fixing, in which unfixed recording paper is sandwiched between a pair of rotating heatable fixing rolls and fixed by heating and pressure, and toner is applied to the recording paper by applying pressure with a pair of fixing rolls. A pressure fixing method (pressure roll fixing) is used in which the image is crushed and fixed. In either fixing method, the recording paper is conveyed and driven by the rotation of the fixing roll.

When such pressure fixing and heat-pressure fixing are applied to continuous paper, it may become stuck between the fixing roll pair due to factors such as poor initial biting into the fixing roll pair, uneven paper thickness, and elongation of the paper due to moisture absorption. The problem is that the continuous paper that has been printed is skewed or meandered, and the position where it is caught in the fixing roll pair changes continuously in the lateral direction, reaching the side edge, causing wrinkles, resulting in poor fixing and abnormal conveyance. be. Therefore, a direction regulating feeding mechanism with a tension applying function is installed between the photosensitive drum and the pair of fixing rolls, and by applying back tension to the continuous paper, it is possible to prevent skewing and meandering.
It is also being considered to automatically restore such abnormalities even if they occur.

(Problems with the prior art) However, unrecoverable conveyance abnormalities may occur due to factors such as external forces applied to the continuous paper, extreme expansion and contraction of the continuous paper, breakdowns in the conveyance system, and even cutting of the continuous paper. Occurs from time to time.

In such a case, if conveyance continues, the continuous paper will become stuck in the conveyance system or drive system, causing a paper jam and putting a load on the device, which in the worst case can lead to failure or destruction, which is a serious problem. be. For this reason, it is necessary to immediately stop the device and stop conveying the continuous paper, but the reaction is slow with manual operation.
An appropriate response is impossible.

(Purpose of the invention) In view of the above-mentioned circumstances, the present invention provides a conveyance trouble detection device for continuous paper with perforations that detects the occurrence of irreversible skew or meandering as an error signal.
is its purpose.

(Means for Solving the Problems) In order to achieve the above object, the conveyance trouble detection device for continuous paper with sprockets according to the present invention is designed to detect the movement of the spout holes in the vicinity of both left and right ends of the continuous paper with sprockets being conveyed. A detecting means is arranged so that the detection area corresponds to each area, and the output signal changes when the sprocket hole is located in the detection area, and an abnormality in conveyance of the continuous paper with the sprocket hole is determined based on the signal from the detection means. and conveyance trouble detection means that outputs an error signal, and the conveyance trouble detection means is triggered by an OR circuit that outputs a logical sum signal of the detection signals from the left and right detection means, and a signal from the OR circuit. and a determination circuit that is retriggered by another signal from the OR circuit within a predetermined time after the trigger and outputs an error signal if the retrigger is not retriggered within the predetermined time. . By using this error signal, conveyance of the continuous paper can be stopped.

(Embodiments of the invention) Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings.

1 and 2 are a side view and a plan view of a conveyance system, respectively, showing an embodiment of a laser beam printer device to which a conveyance trouble detection device for continuous paper with perforations according to the present invention is applied; Fan-hold paper 10 is produced as continuous paper with perforations using the electrophotographic method using input printing information from etc.
It is printed and output.

Around the photosensitive drum 1, there are a toner cleaning section 2, a static eliminator 3, a charging section 4, a scanning optical system 5 that guides a laser beam modulated based on input information onto the photosensitive drum 1, a developing section 6, and a transfer section 7. They are appropriately arranged in the above-mentioned order along the rotational direction of the photosensitive drum 1 (see the arrow in FIG. A direction regulating feeding mechanism 9 having a tension imparting function during the conveyance path of the fan-hold paper 10 to the fixing unit 8 and a detector 3 as a detection means for detecting the feed hole 10A of the fan-hold paper 10
1 and 32 are installed.

Then, the photosensitive drum 1 is rotated (sub-scanning) and the surface of the photosensitive drum 1 is scanned (main scanning) in the longitudinal direction of the photosensitive drum 1 with a laser beam from the scanning optical system 5, thereby forming a The latent image is visualized as a toner image by the developing section 6, and the toner image is conveyed by the fixing section 8 at the same speed as the rotational circumferential speed of the photosensitive drum 1.
Then, the image is transferred by the transfer section 7 and fixed by the fixing section 8 before being discharged.

The fixing unit 8 includes a pair of upper and lower pressure rolls 81A, 8.
1B constitute a pair of fixing rolls 81, and the distance between the outer peripheries of both pressure rolls 81A, 81B is such that when the fan-hold paper 10 is sandwiched between the two pressure rolls 81A, 81B, the fan-hold paper 10 is applied with a predetermined pressure. The interval is set to apply pressure.

The upper pressure roll 81A is connected to a drive motor 20 via a chain (not shown), and is rotated by the drive motor 20 to fix the unfixed fan-hold paper 10 between the pair of fixing rolls 81.
The fan-hold paper 10 is pressed with a predetermined pressure to crush and fix the toner (so-called pressure fixing method), and at the same time, the fan-hold paper 10 is conveyed and discharged from the apparatus.

Note that the rotational circumferential speed of the photosensitive drum 1 and the pressure roll 8 are
The rotation peripheral speeds of the sheets 1 and 1 are the same, therefore, the peripheral speed is the conveyance speed of the fan-hold paper 10 during normal operation.

Further, the drive motor 20 is used not only to drive the pair of fixing rolls 81 but also as a drive source for other drive mechanisms related to conveyance of the fan-hold paper 10 such as rotation of the photosensitive drum 1. fan hold paper 10 by controlling the rotation of
It is possible to control the transportation of As shown in the control block diagram of FIG. 3, the drive motor 20 is rotationally controlled by a control device 60 including a transport trouble detection circuit 61 as a transport trouble detection means.

The direction regulating feeding mechanism 9 includes tension belts 9 below feeding holes at both left and right ends of the fan-hold paper 10 that is conveyed from the transfer section 7 to the fixing section 8.
1 and 91 are installed parallel to the transport direction so as to be able to rotate with a predetermined rotation resistance.

For example, on the surface of the tension belt 91, there is a
A plurality of protrusions 91A that fit into the feed holes 10A formed at 2-inch intervals are protruded in a line around the entire circumference at the same pitch (1/2 inch) as the feed holes 10A. By fitting and engaging the projection 91A into the feed hole 10A of the fan-hold paper 10, the fan-hold paper 10 is rotated as the fan-hold paper 10 is conveyed while applying back tension and regulating its direction. It is something that

That is, the tension belt 91 has a protrusion 91A.
The transport direction of the fan-hold paper 10 is regulated by the fan-hold paper 10, and the direction-regulating feeding mechanism 9 and the fixing unit 8 are
It applies tension to the fan-hold paper 10 between the fan-hold paper 10 to prevent skewing and meandering, and even if some skewing or meandering occurs, it automatically corrects it.

The detectors 31 and 32 that detect the feed hole 10A of the fan-hold paper 10 are so-called transmission type photointerrupters in which a light source and a light receiving element are separated by a predetermined interval, and the feed hole 10A passes through the light projection position of the light source. The feed hole 10A is detected only when the light beam enters the light receiving element. These detectors 31 and 32 are connected, for example, from the direction regulating feeding mechanism 9 to the fixing unit 8 as shown in FIG.
The light emitting position is fixedly installed on both the left and right sides of the chassis 40 between the fan-hold paper 10 and the center of the feed hole 10A of the fan-hold paper 10 during normal conveyance.

The drive control system including the conveyance trouble detection device for continuous paper with feed holes according to the present invention is configured to detect the conveyance trouble detection circuit 61 from each signal of the detectors 31 and 32 as shown in FIG. An abnormal conveyance state is detected, and the control device 60 controls the drive motor 20 to stop the conveyance drive.

Next, a specific circuit configuration of the conveyance trouble detection circuit 61 for continuous paper with feed holes according to the present invention will be explained with reference to FIG.

In the same figure, a conveyance trouble detection circuit 61 is configured by converting the output of the photo interrupter drive circuit and light receiving element into a square wave through detectors 31 and 32 (photo interrupter drive circuit and light receiving element output) installed on both sides of the fan hold paper 10 as shown in FIG. signal PT ₁ from (including a waveform shaping circuit),
OR circuit 6 that inputs PT ₂ and calculates the logical sum of them
1A and the output signal S ₁ of this OR circuit 61A are input to the input terminal IN, and when the Q output is at a low level, it is used as a determination circuit that uses it as an error signal. , 61B (abbreviated as ``retriggerable monomulti'').

In addition, in this retrigger Bruno multi 61B,
The time Tx during which retriggering is allowed is determined by an external resistor R and capacitor C, but this time Tx depends on the conveyance speed of the fan-hold paper 10, the pitch of the feed holes 10A, and the fan-hold paper 1.
Select a period during which it is thought that 0 oblique/meandering can be automatically restored.

Next, the operation of this conveyance trouble detection circuit 61 will be explained based on time charts of each signal (PT ₁ , PT ₂ , S ₁ , and Error signal).

FIG. 6 shows a time chart under normal conveyance conditions. In this case, the light emitting paths of the detectors 31 and 32 are directed to the left and right feed holes 10 of the fan hole paper 10, respectively.
Since it is located approximately at the center of A, the frequencies of the signals PT ₁ and PT ₂ are synchronized with the conveyance speed of the fan hold paper 10.
A signal is sent every time the feed hole 10A passes through the light projection path.
PT ₁ and PT ₂ become Low level, and become High level every time the optical path is blocked by the paper surface.

Since the fan-hold paper 10 is being conveyed normally, the signal PT ₁ and the signal PT ₂ are approximately in phase, and therefore, the logical sum of these two is calculated.
The output signal S ₁ of the OR circuit 61A also has substantially the same phase as the signals PT ₁ and PT ₂ .

Here, the retriggerable mono multi 61B is triggered at the rising edge of this signal _S1 , but if the retrigger permissible time Tx of the retriggerable mono multi 61B is set to be sufficiently longer than the period of the rising edge of the signal _S1 . , the Q output is always at a high level, and this state may be regarded as a normal conveyance state.

Next, FIG. 7 shows a time chart of each signal when, for example, the fan-hold paper 10 moves obliquely toward the detector 31 on the detector 32 side, and the feed hole 10A is removed from the light emitting path of the detector 32. show.

In this case, assuming normal conveyance on the detector 31 side, the signal PT ₁ indicates that the light emitting path of the detector 31 is above the feed hole 10A of the fan hold paper 10, as in the case shown in FIG. Then it becomes a low level, and when it is blocked by that paper, it becomes a high level.

Here, the fan hold paper 10 is
When the beam moves obliquely toward the detector 31, the output signal _PT2 of the detector 32 continues to be at a high level from the moment the feed hole 10A is removed from the light projection path. Then,
Since the OR circuit 61A takes the logical sum of the signals PT ₁ and PT ₂ , the change in the output of the signal PT ₂ described above is output as is as the signal S ₁ .

Therefore, the feed hole 1 of the fan hold paper 10
The retriggerable monomulti 61B, which has been retriggered in synchronization with 0A, has the feed hole 10A connected to the detector 32.
It is no longer triggered at the rising edge of the signal _S1 corresponding to the instant the light exits from the light projection path.

As a result, the Q output falls to a low level after the preset retrigger allowable time Tx described above, and the time after this Q output reaches a low level is used as an error signal to detect an abnormal conveyance state, that is, the occurrence of an error. Let's assume that we did.

In FIG. 8, the fan-hold paper 10 is moved to the center, and the light emitting paths of both detectors are directed toward the feed hole 10.
A time chart of the paper signal when it deviates from A is shown.

In this case, the output change of the signal from the detector on the side where the light emitting light path first deviates from the feed hole 10A is the signal S ₁
In the example of FIG. 8, the signal PT ₂ is shown as being the first to go off. Then, as in the example of FIG. 7, the Q of the retriggerable monomulti 61B
The output will fall to low level after the retrigger tolerance time Tx from the last rise of signal S ₁ ,
This allows the occurrence of an error to be detected.

In both the example shown in Fig. 7 and the example shown in Fig. 8, the retriggerable monomulti 61B is
Although the error signal is output after the retrigger permissible time Tx, if the amount of skew or meandering of the fan hold paper 10 is small, the direction regulating feeding mechanism 9
Assuming that the output signal _S1 of the OR circuit 61A successfully recovers naturally due to the back tension _of
Of course, a change in the output of PT ₂ appears, but if there is a skew or meandering within the retrigger allowable time Tx, the retriggerable mono multi 61B will return to the normal conveyance state before the Q output becomes low level. It is retriggered by the signal _S1 and continues to indicate a normal conveyance state while remaining at High level.

For this reason, the retrigger permissible time Tx of the retriggerable multi 61B needs to be set in anticipation of the time when it is thought that natural recovery is possible, and is set accordingly.

The example shown in FIG. 7 is a case where the conveyance change of the fan-hold paper 10 occurs only on the detector 32 side, but in reality, the conveyance change occurs also on the detector 31 side or on the eighth side.
As in the example shown in the figure, changes in conveyance can also be considered on both sides. However, in any of these cases, the OR circuit 6
Since the logical sum is obtained by 1A, a change in the transport will eventually appear in the signal _S1 , and a transport abnormality can be detected when the Q output becomes a low level.

In this way, when the conveyance abnormality of the fan hold paper 10 is detected as an abnormal conveyance state, a low level error signal is output from the Q output terminal of the retriggerable monomulti 61B, and this error signal causes the control device 60 to control the drive motor 20. It becomes possible to stop the fan-hold paper 10 and stop the printing.

Therefore, with this configuration, it is possible to prevent paper jamming or jamming of the fan-hold paper 10 into the conveyance system and drive system even when irreversible skewing or meandering occurs.

In the above embodiment, the continuous paper is conveyed by the fixing unit 8, but the fixing unit 8 is not particularly limited to driving the conveyance of the continuous paper. Needless to say, the present invention is also applicable to those equipped with a mechanism.

Furthermore, although the detectors 31 and 32 are configured as transmission type photo interrupters, it goes without saying that they may be configured as reflective type photo interrupters.

Furthermore, each signal from both detectors 31 and 32
The logic of PT ₁ and PT ₂ is reversed using an inverter, etc. to create signals ₁ and ₂ , and the signal S ₁ is the logical sum of these signals.
If the configuration is changed to trigger the retriggerable monomulti (changed to the falling trigger type) 61B at the falling edge of , each signal will become as shown in FIG. 9.

Due to this change, the re-trigger permissible time is set after both signals ₁ and ₂ become low level and the pulse signal corresponding to the sprocket hole 10A is no longer output.
An error signal is now output after Tx, and the 9th
The figure shows this situation. In this way, only when the feed hole 10A is out of the light emitting path of both detectors for a certain period of time, an error signal will be output as an abnormal conveyance state, thereby widening the range that is considered to be a normal conveyance state (conveyance state). In this way, it is possible to make the state of transport abnormality less severe.

(Effect of the invention) According to the conveyance trouble detection device for continuous paper with perforations according to the present invention, the perforations at both ends of the continuous paper are detected by the detector, and the detection signal of the perforations is detected within a preset time. In other words, if skew and meandering of a predetermined amount or more continue for a predetermined amount of time or more, an error signal is output as an abnormal conveyance state of the continuous paper. If this error signal is used as a stop signal for the transport system and drive system, paper jams and jams of continuous paper in the transport system and drive system can be prevented.

Therefore, the burden on the conveyance system and drive system caused by the continuous paper being caught is extremely reduced, and it is possible to prevent failure and damage to the apparatus due to abnormal conveyance of the continuous paper.

[Brief explanation of the drawing]

Fig. 1 is a side configuration diagram of an embodiment of a printer using the transport trouble detection device for continuous paper with feed holes according to the present invention, Fig. 2 is a plan view of its transport system, and Fig. 3 is its control block diagram. , FIG. 4 is a partially enlarged perspective view of the detectors 31 and 32 in FIGS. 1 and 2, and FIG. 5 is a specific circuit configuration diagram showing an example of a conveyance trouble detection device for continuous paper with feed holes. , 6th
7, 8, and 9 are operation time charts, respectively. 10... Fan-hold paper (continuous paper with feed holes), 31, 32... Detector (detection means for detecting the feed holes of continuous paper with feed holes), 61... Conveyance trouble detection circuit (conveyance trouble detection means) , 61
A...OR circuit, 61B...Retriggerable mono multivibrator (judgment circuit).

Claims (1)

[Scope of Claim for Utility Model Registration] In a printer that prints information on continuous paper with perforations, the detection area corresponds to the movement area of the perforation near both left and right ends of the continuous paper with perforations being conveyed. a detection means arranged so as to change an output signal when the feed hole is located in the detection area; and a detection means that determines a conveyance abnormality of the continuous paper with the feed hole based on the signal from the detection means and outputs an error signal. and a conveyance trouble detection means, the conveyance trouble detection means comprising an OR circuit that outputs a logical sum signal of the detection signals from the left and right detection means, and an OR circuit that is triggered by the signal from the OR circuit and detects the A determination circuit that is retriggered by a signal from the OR circuit again within a predetermined time after the trigger and outputs an error signal if the retrigger is not retriggered within the predetermined time. A conveyance trouble detection device for continuous paper with feed holes, characterized by the following.