JPH11277819A - Printer and print medium jam detector therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine occurrence of paper jam correctly in a printer. SOLUTION: The paper jam detector for printer comprises a rotation detector 8 for detecting the rotational state of a driven roller 2 turning through contact with a continuous paper being carried by a drive roller in the form of iterative state change of output signal, and a decision means 9 for detecting the output signal every unit time of essential iterative state change when the output signal from the rotation detector 8 has no state change and making a decision that 'paper jam has occurred' if the integrated value of the number of detecting times of same state is equal to a preset reference value thus stopping a paper feed motor 10. Since a decision is not made that 'paper jam has occurred' when rotation of the driven roller stops, the paper feed motor is not stopped erroneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driven roller which rotates in contact with a print medium conveyed by a driving roller,
Rotation detection means for detecting the rotation of the driven roller and detecting the rotation state as a repetition of a change in the state of the output signal, and receiving the output signal of the rotation detection section to determine a print medium clogging. The present invention relates to a printing medium clogging detection device for a printing device and a printing device provided with the same.

[0002]

2. Description of the Related Art As a first prior art of a printing medium clogging detecting device in this type of printing apparatus, Japanese Patent Laid-Open Publication No.
No. 2854. In this detection device, continuous paper as a printing medium is conveyed by a driving roller, a driven roller is rotatably mounted on the shaft of the driving roller, and the continuous paper is conveyed in a state of being in contact with the driven roller. The driven roller rotates. Then, the rotation of the driven roller is detected by a rotation detector,
When the rotation of the driven roller stops, it is determined that the continuous paper is jammed and is no longer conveyed, and the paper jam is determined.

[0003] The driven roller is provided with a ring-shaped magnet in which magnets are magnetized so that adjacent segments have different polarities on the boundary line in the radial direction, and the rotation detector detects a change in the magnetic field. It consists of a Hall element to be detected. Then, since the magnetic field changes due to the rotation of the driven roller, the rotation state is detected by the rotation detector. Specifically, the rotation state of the driven roller is detected as a repetition of a state change in the output signal of the rotation detector.

FIG. 4 is a timing chart showing this. The driven roller rotates every one step (in the state of H) of the paper feed motor, and the magnetic field change based on the rotation is repeated, and this is shown by the rotation detector in the rotation detector signal (1) of FIG. As described above, the output signal is detected as a repetition of the state change. In this example, the state change of the output signal (L → H and H → L) is 6
It is to be repeated times. When the rotation of the driven roller stops due to a paper jam, regular repetition as indicated by the rotation detector signal (1) is not performed. Therefore, it is determined that a paper jam has occurred. As shown in FIG. 5, when the uniformly flat continuous paper 1 as a print medium is conveyed in contact with the driven roller 2 made of a rubber ring so as to be tightly wound at a winding angle θ0, this rule is generally applied. Signal pattern.

[0005] However, the power of rotation of the driven roller 2 is a frictional force based on the contact with the conveyed continuous paper 1. The frictional force is set to be larger than the rotational resistance of the driven roller 2 itself to the shaft 3, but both of them slightly fluctuate. This variation may break the magnitude relationship between the two. In such a case, the driven roller 2 and the paper 1
Is temporarily in a slip state and the rotation of the driven roller 2 is temporarily stopped, so that the regular output signal pattern is slightly broken. In particular, as shown in FIG. 8, in the case where the continuous paper 1 is stored in the box 5 in a state of being folded through the fold line 4, if the continuous paper 1 is applied to a printing device, the slip is more likely to occur. The reason is that even if the continuous paper 1 is taken out of the box 5 and stretched, as shown in FIG. 9, "crests" and "valleys" of the folds remain, so that even if such paper is wound around the driven roller 2, FIG. Also, as shown in FIG. 7, winding is performed only at a small winding angle (θ1 <θ0, θ2 <θ0), the contact area is reduced, and the frictional force for rotating the driven roller 2 is also reduced. The rotation detector signal (2) in FIG. 4 is a signal pattern when the driven roller 2 temporarily stops due to the temporary slip. In the figure, the flat areas 5 and 6 where there is no change in the output signal correspond to the fact that the rotation of the driven roller 2 is temporarily stopped due to the slip. 5 to 7, reference numeral 7 denotes a bush.

Further, as a second prior art, Japanese Patent Laid-Open No.
There is a paper jam erroneous detection prevention system disclosed in JP-A-316276. In this paper jam erroneous detection prevention system, when a tractor rotated by a motor feeds a paper, a roller pressed against the paper rotates due to friction with the paper. Then, whether or not this roller is rotating is detected once for each paper feeding operation,
When the count detected as “not rotating” reaches a predetermined value, it is determined that a paper jam has occurred.

The roller, together with a step motor connected thereto, constitutes a paper jam detecting means. When the roller rotates, the step motor also rotates, and the step motor generates an AC voltage. This AC voltage is
When the roller is rotating, it is converted to a signal of "1" by the capacitor and the comparison circuit, and when the roller is not rotating, it is converted to a signal of "0", and is sent to the counting means. The counting means uses a detection timing signal given once at a certain time during one paper feeding operation.
When "0" is input, the count is increased, and when "1" is input, the count is reduced (however, it does not become zero or less). When the count value of the counting means reaches a predetermined value, it is determined that a paper jam has occurred, and the count value of the counting means is reset to zero.

[0008]

In the output signal pattern such as the rotation detector signal (2) in FIG. 4, the rotation of the driven roller 2 is temporarily stopped, but is immediately restarted. As is clear from the above, the transport state of the continuous paper 1 is normal. That is, no paper jam has occurred. Nevertheless, the paper jam detection device in the first prior art is
Even in such a case, since the rotation of the driven roller is stopped, it is immediately determined that a paper jam has occurred.Therefore, although the paper is normally conveyed, it may be erroneously determined that the paper is jammed. there were. In other words, the conventional paper jam detector has a problem that the sensitivity cannot be determined correctly because the sensitivity is too high.

Next, the paper jam erroneous detection prevention system according to the second prior art detects a paper feed state by a detection timing signal given once at a certain time during one paper feed operation. . From this fact, if the roller is rotating normally except at the time of the detection timing signal, and the state where the roller does not rotate due to slip at the time of the detection timing signal occurs a predetermined number of times, the paper feeding is normally performed. In spite of this, there was a problem that the paper jam was erroneously determined.

[0010] The paper jam erroneous detection prevention method includes:
Since the state of the paper feed is detected only once for each paper feed operation, the paper jam cannot be determined unless the paper is fed several times. For this reason, when the amount of paper fed once is large (for example, when paper is fed over several to several tens of lines).
However, even if a paper jam occurs, it is counted only once, so that it is not possible to determine that the paper jam is a true paper jam, and there is a problem that the paper continues to be fed.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to correctly determine the occurrence of clogging of a printing medium in a printing apparatus.

[0012]

According to a first aspect of the present invention, there is provided a driven roller rotating in contact with a print medium conveyed by a driving roller, and a rotation of the driven roller. Rotation detecting means for detecting and detecting the rotation state as a repetition of the state change of the output signal; and receiving the output signal of the rotation detection means, and when the state change of the signal is "absent", the state change originally occurs. The state of the output signal is detected for each unit time in which is repeated, and when the integrated value of the number of consecutive detections of the same state becomes equal to a preset reference value, it is determined that “print medium clogging”, and the print medium is determined. And a determination unit for stopping the conveyance of the print medium.

Thus, the stop of the rotation of the driven roller is not immediately determined to be "print medium jam" as in the first prior art, so that there is no danger of erroneously stopping the conveyance of the print medium. Further, the state of the output signal is detected for each unit time, and when the integrated value of the number of continuous detections of the same state is compared with the reference value and becomes the same value, it is determined that "print medium jam". Therefore, the rotation stop of the driven roller caused by the temporary slip and the rotation stop of the driven roller caused by the clogging of the print medium can be distinguished with high accuracy.
This makes it possible to correctly determine whether the print medium is clogged.

Further, the rotation of the driven roller is detected, and the rotation state is detected as a repetition of a change in the state of the output signal.
Since the state of the output signal is originally detected every unit time in which the state change is repeated, the transport state is always detected. Therefore, even if a temporary slip or jam of the print medium occurs at any point during transport,
These can be accurately determined. Further, in the second prior art, as described above, when the slip state happens to occur a predetermined number of times at the time of the detection timing signal, there is a problem that this is erroneously determined as a paper jam, but this problem is also avoided. it can. In other words, even with this, the rotation stop of the driven roller due to the temporary slip and the rotation stop of the driven roller due to the clogging of the print medium can be distinguished with high accuracy, and the correct determination of the print medium clogging can be performed. become.

Here, the reference value is a value that is used as a reference for giving a determination result that the printing medium is clogged, and is determined based on an empirical rule or the like.

According to a second aspect of the present invention, there is provided a driven roller which rotates in contact with a print medium conveyed by a driving roller, detects the rotation of the driven roller, and detects the rotation state of the output signal. A rotation detection unit that detects the change as a repetition, and receives an output signal of the rotation detection unit, and if the state change of the signal is “present”, printing is continued as it is; The state of the output signal is detected for each unit time in which the state change is repeated, and when the integrated value of the number of consecutive detections of the same state becomes the same as a preset reference value, it is determined that the printing medium is clogged, Stop the conveyance of the print medium, and if the state change of the output signal becomes “present” before the integrated value becomes the same as the reference value, determine that “temporary slip” and reset the integrated value. Judge If a print media jam detection device of the printing apparatus equipped with.

With this, it is possible to correctly determine whether the print medium is clogged, and when the integrated value is equal to or less than the reference value and there is a change in the state of the output signal, it is determined that the slip is temporary and the integration up to that point is terminated. Therefore, even if a temporary slip state occurs occasionally, it is possible to correctly determine whether or not the print medium is clogged with the same accuracy each time.

According to a third aspect of the present invention, in the first or second aspect, the reference value is variable. Thereby, the sensitivity of the print medium clogging detection can be freely adjusted according to the habit of the print medium being conveyed and other conditions.

According to a fourth aspect of the present invention, there is provided a driven roller which rotates in contact with a print medium conveyed by a driving roller, detects the rotation of the driven roller, and detects the rotation state of the output signal. A rotation detecting means for detecting the change as a repetition, and receiving an output signal of the rotation detecting means, and when the state change of the signal is "absent", the duration of the "absent" state is measured. Is determined as `` print medium clogging '' when the reference time is the same as a preset reference time, determining means to stop the transport of the print medium,
This is a printing medium clogging detection device of a printing device provided with:

Thus, instead of the "integrated value" in the first aspect of the present invention, the duration of the output signal without change in state is measured and compared with the reference time. The same operation and effect as described above can be obtained. Here, the “reference time” is determined based on an empirical rule or the like in the same manner as the “reference value”.

According to a fifth aspect of the present invention, there is provided a driven roller which rotates in contact with a print medium conveyed by a driving roller, detects the rotation of the driven roller, and detects the rotation state of the output signal. A rotation detecting means for detecting the change as a repetition, and receiving an output signal of the rotation detecting means, and when the state change of the signal is "present", printing is continued as it is; when the state change is "absent", the printing is continued. The continuation time of the state of "absence" is measured, and when the continuation time becomes the same as the preset reference time, it is determined that "print medium jam" and the conveyance of the print medium is stopped, and the continuation time is determined. When the state change of the output signal becomes “present” before the output time becomes equal to the reference time, the determination means resets the measurement of the duration by determining that the slip is “temporary slip”. Printing media filling It is a Ri detection device.

With this, it is possible to make a correct determination as to whether the print medium is clogged, and when there is a change in the state of the output signal while the duration is shorter than the reference time, it is determined that the slip is temporary and the time measurement up to that time is measured. Since the process is terminated and reset, even if a temporary slip condition occurs occasionally, it is possible to correctly determine whether or not the print medium is clogged with the same accuracy each time.

The invention according to claim 6 of the present application is characterized in that, in the invention according to claim 4 or 5, the reference time is variable. As a result, the sensitivity of the detection of the clogging of the print medium can be freely adjusted in accordance with the habit of the print medium being conveyed and other conditions as in the case of the third aspect.

[0024] The invention described in claim 7 of the present application provides claims 1 to
6. In the invention according to any one of 6, the state change of the output signal when the driven roller is rotating normally is:
It is characterized in that the printing operation is performed a plurality of times for one transport operation of the printing medium.

Thus, the rotational state of the driven roller can be detected with higher accuracy, and as a result, a more accurate determination can be made. In addition, when the print medium is clogged, the status change is “none” even during one transport operation.
Can be detected a plurality of times. Therefore, even during a single transport operation, it is possible to determine that the print medium is clogged when the integrated value reaches the reference value. Therefore, it is possible to overcome the problem that the print medium cannot be determined unless the paper is fed several times as in the second related art.

The invention described in claim 8 of the present application provides
7. The invention according to claim 7, wherein the transport of the print medium is performed by a stepping motor driven by a pulse signal, and the determination unit captures a state of an output signal of the rotation detection unit for each step of the motor. The above-mentioned determination is performed. Thus, the integrated value or the duration is obtained by associating the conveyance of the print medium by the stepping motor with the state of the output signal of the rotation detector, so that highly accurate determination can be easily performed.

The ninth aspect of the present invention provides the first aspect.
8. The invention according to any one of the above 8, wherein the printing medium is a continuous paper folded via a fold. In the case of such folded continuous paper, slippage is particularly likely to occur between the driven roller and the continuous paper. Therefore, the above-described operation and effect are remarkable in an apparatus for printing such continuous paper.

[0028] The invention described in claim 10 of the present application is directed to claim 1.
9. The invention according to any one of claims 1 to 9, wherein the rotation detecting means detects a change in a magnetic field, and outputs the detected change in the magnetic field as a change in the state of an output signal. Wherein the magnet is magnetized so that the magnetic field detected by the rotation detecting means changes with the rotation of the magnet.

As a result, when the driven roller rotates, the magnet also rotates, causing a change in the magnetic field. Therefore, the signal provided from the rotation detecting means to the determination means includes a change corresponding to the change in the magnetic field due to the rotation of the magnet. Occurs. On the other hand, if the driven roller does not rotate, the magnet does not rotate, so that the magnetic field does not change. As a result, the signal given from the rotation detecting means to the determining means does not change. Therefore, the presence / absence of rotation of the driven roller can be accurately communicated to the determination means, and thus, it is possible to correctly determine whether the print medium is clogged.

[0030] The invention described in claim 11 of the present application is claim 1.
In the invention according to any one of the first to ninth aspects, the rotation detecting unit includes a light emitting unit and a light receiving unit, and outputs a change in the amount of light received by the light receiving unit as a state change of an output signal. A reflecting plate that rotates with the rotation of the driven roller, wherein the reflecting plate is arranged to reflect light from the light emitting unit and make the reflected light incident on the light receiving unit; The light-reflecting portion is colored so that the reflectance of light changes with the rotation of the reflector.

Thus, when the driven roller rotates, the reflection plate also rotates, and the reflectance of the light receiving portion of the reflection plate changes, so that the amount of light received by the light receiving means of the rotation detecting means also changes. As a result, a signal corresponding to a change in the amount of received light occurs in a signal provided from the rotation detecting unit to the determining unit. On the other hand, if the driven roller does not rotate, the reflection plate also does not rotate, so that the amount of received light does not change, and as a result, there is no change in the signal given from the rotation detecting means to the determining means. Therefore, the presence / absence of rotation of the driven roller can be accurately communicated to the determination means, and thus, it is possible to correctly determine whether the print medium is clogged.

[0032] The invention described in claim 12 of the present application is claim 1.
In the invention according to any one of Items 1 to 9, the rotation detecting means detects irregularities on the surface of the object, and outputs a change in the detected irregularities as a state change of an output signal. A member that rotates with the rotation of the driven roller is provided, and the member has a surface formed so that a change in unevenness is detected by the rotation detecting unit with the rotation thereof. Things.

As a result, when the driven roller rotates, the member also rotates, and as a result, a signal corresponding to a change in the unevenness of the member occurs in the signal given from the rotation detecting means to the determining means. On the other hand, if the driven roller does not rotate, no change occurs in the unevenness of the member, and as a result, there is no change in the signal given from the rotation detecting means to the determining means. Therefore,
The presence / absence of rotation of the driven roller can be accurately communicated to the determination means, and thus, a correct determination of a print medium jam can be made.

The invention described in claim 13 of the present application is the invention of claim 1
13. A printing apparatus comprising the print medium clogging detection device according to any one of claims 12 to 12. This prevents the printing from being stopped by mistake, so that the printing apparatus can perform stable printing.

[0035]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a paper jam detection device according to the present invention, FIG. 2 is a flowchart of paper jam detection according to the present invention, and FIG. 3 is a timing chart of paper jam detection according to the present invention. .

As shown in FIG. 1, in this embodiment, the rotation of the driven roller 2 is detected by the rotation detector 8, and the output signal of the rotation detector 8 is sent to the judging means 9. When the regular pattern of the output signal of the rotation detector 8 is broken by the determining means 9, it is determined whether "paper jam" is occurring or "temporary slip". Is determined, the paper feed motor 10 is stopped. here,
As shown in FIG. 10, the driven roller 2 is provided with a ring-shaped magnet 22 in which magnets are magnetized so that adjacent segments have different polarities with respect to a radial boundary line. The rotation detector 8 includes a Hall element 82 that detects a change in a magnetic field. Further, the paper feed motor 10 is composed of a stepping motor. These points are the same as in the first prior art (Japanese Patent Laid-Open No. 6-31854).
The place where the driven roller 2 is provided is preferably the shaft of the driving roller as in the above-described prior art, from the viewpoint of reducing the risk of printing misalignment and the like. Of course.

Subsequently, based on the flowchart shown in FIG.
Will be described. First, in step 51, the output signal of the rotation detector 8 is fetched for each step of the paper feed motor 10 (usually about 1/216 inch / step), and whether the state change of the signal is regular or not is determined. Is determined. Specifically, there is no slip or the like between the driven roller 2 and the paper 1, and the unit detects the actual state of the output signal at each unit time when the state change of the signal should be repeated. When the signal state (for example, the L state) and the subsequent signal state (for example, the H state) are different (for example, the signal pattern 11 at the left end of the rotation detector signal (3) shown in FIG. 3), that is, the signal is regular. When a state change is detected, it is determined that the paper is in a completely normal state.
Then, as in step 52, the paper feed motor 10 continues to be driven.

On the other hand, when there is no state change, that is, the output signal remains in the L state (the area 12 of the rotation detector signal (3) and the area 5 in the (2) of FIGS. 3 and 4) or the H state. When it is referred to (region 13 of rotation detector signal (4) in FIG. 3 and FIG. 4 and region 6 of (2)), the process proceeds to step 53, where "temporary slip" is caused or "paper jam" is detected. Determine the cause. Specifically, the signal state is detected at each unit time, and the number of consecutive detections of the same state (remaining in the L state or H state) is integrated by a memory counter or the like, and the integrated value is set to a predetermined reference value. When the value becomes equal to the threshold value (the areas 12 and 13 of the rotation detector signals (3) and (4) in FIG. 3), it is determined that a “paper jam” has occurred. When there is a state change of the output signal before the output signal becomes equal to the reference value (FIG. 4)
Are determined to be "temporary slips". It can be said that such a determination method for obtaining the integrated value is equivalent to passing through a controllable buffer function. Here, the reference value is a value serving as a reference for providing a determination result of “paper jam”, and is determined based on an empirical rule in consideration of a folding habit of continuous paper or the like. In this example, the reference value is set to 360 in consideration of the creased continuous paper shown in FIG. This is because a slip phenomenon tends to occur particularly in the case of such a folded continuous paper. Note that the reference value is desirably formed so that the set value can be appropriately changed. By making the setting of the reference value changeable in this manner, the sensitivity can be freely changed in accordance with the characteristics of the detection mechanism, the habit of the continuous paper, and the like, thereby making it easier to make adjustments for performing high-precision determination. Become.

If the judging means 9 judges that the stop of the driven roller is caused by "paper jam", step 54 is executed.
To output a drive stop signal to the paper feed motor 10 to stop it. If the determination result of "paper jam" comes out while the paper feed motor 10 is accelerating, the vehicle immediately decelerates and stops, and if the determination result comes out while the paper feed motor 10 is at a constant speed, it decelerates immediately. If the determination result is output while the paper feed motor 10 is being decelerated, the deceleration state is continued and stopped. After this stop, when a switch other than the pause switch and the pitch switch (both not shown) is pressed, a buzzer alerts the user, and when the paper jam is corrected and printing is restarted, the pause switch is used. Is good.

On the other hand, in step 53, "temporary slip"
If it is determined that this is the cause, the integration processing up to that point is terminated in step 55 and reset.
It is going to 2.

According to the above embodiment, the driven roller 2
Is not immediately determined as a "paper jam", so that there is no danger of stopping the paper feed motor 10 by mistake. In addition, since the integrated value of the number of consecutive detections of the same signal state is compared with the reference value for each unit time, the rotation of the driven roller 2 due to the temporary slip and the paper jam The rotation stop of the driven roller 2 can be distinguished with high accuracy, and a correct determination of a paper jam can be made. Furthermore, when it was judged as "temporary slip", the integration up to that point was terminated and reset, so
Even if a temporary slip condition occurs from time to time, the reset can correctly determine "whether or not a paper jam" with the same accuracy each time.

The judgment by the judging means 9 is preferably performed so that the paper feed by the paper feed motor 10 is started after the printing of the first line print area is completed.
At this point, the paper discharge unit (not shown) is closed and slack is removed, and the paper conveyance operation is in a stable area. Therefore, when determining whether or not the paper is jammed, the paper is affected by the noise due to the slack or the like. Because it is difficult. Further, the integration process may be performed regardless of whether the paper feed is in the normal rotation direction or the reverse rotation direction, that is, regardless of the paper feed mode. However, it is desirable that the N steps immediately after the paper feed direction changes from the normal rotation to the reverse rotation or from the reverse rotation to the normal rotation are not included in the determination in order to obtain a highly accurate determination result that is not affected by noise. Here, N corresponds to 1.5 times the minimum resolution (step conversion) of the magnet.

Next, another embodiment of the present invention will be described. In this example, when the state change of the output signal is “absent”, the judging means 9 is formed to measure the duration of the “absent” state. Then, when the continuation time becomes equal to the preset reference time, it is determined that “paper jam” and the paper feed motor 10 is stopped,
When the state change of the output signal becomes “present” before the duration becomes the same as the reference time, it is determined to be “temporary slip” and the measurement of the duration is reset. . Other configurations are the same as those of the above embodiment.

Also according to the duration and the reference time, a correct determination of a paper jam can be made in the same manner as in the embodiment, and when the duration is less than the reference time and the state of the output signal changes, Since it was determined to be a temporary slip and the time measurement up to that point was terminated and reset, even if a temporary slip condition sometimes occurred,
Each time, it is possible to correctly determine whether or not a paper jam has occurred with the same accuracy. Here, the “reference time” is determined based on an empirical rule or the like in the same manner as the “reference value”. In addition, it is desirable that the “reference time” is set to be changeable similarly to the “reference value” for the same reason.

In each of the above embodiments, the continuous paper 1 as a printing medium has been described as a creased continuous paper. However, the present invention is not limited to this creased continuous paper. The present invention is also applicable to such flat paper because there is a risk of slipping even on flat paper without folds.

As another embodiment of the present invention, FIG.
As shown in (A) and (B), the driven roller 2 is provided with a ring-shaped reflecting plate 24, and the rotation detector 8 includes a light receiving / emitting device 84. The ring-shaped reflector 24 includes
Adjacent segments are provided with the radial boundary as a boundary, and these segments are alternately arranged in colors having different light reflectivities (for example, white (W) and black (B)). The light emitting and receiving device 84 includes a light emitting device 841 (for example, a light emitting diode) that irradiates light to the ring-shaped reflecting plate,
A light receiver 842 (e.g., a light receiver) that receives light emitted by the light emitter 841 and reflected by the ring-shaped reflector 24.
A phototransistor), and outputs a change in the amount of light received by the light receiver 842 as an output signal. When the driven roller 2 rotates, the ring-shaped reflection plate 24 also rotates, and as a result, the light irradiation portion of the light emitter 841 changes alternately from white to black and from black to white. Since the reflectivity of light is different between black and white, the amount of light reflected by the reflector 24 and received by the light receiver 842 changes periodically.
2 also changes periodically. On the other hand, the driven roller 2
When is not rotating, there is no change in the amount of received light, so that the output signal from the light receiver 842 does not change. Thus, the light receiving / emitting device 84 can accurately transmit the presence or absence of rotation of the driven roller 2 to the determination unit 9 (FIG. 1) as the presence or absence of a change in the output signal.

In the ring-shaped reflector 24, it is not necessary that the entire segment adjacent to the boundary in the radial direction is colored, and even if only the portion that reflects the light from the light emitter 841 is colored. It goes without saying that it is good. Also, in FIG. 11A, the disk surface of the ring-shaped reflector 24 is colored, but not the disk surface but the cylindrical surface, and the light emitting / receiving device 84 is irradiated with light to the cylindrical surface. It can be installed at a position to receive the reflected light. Further, instead of providing the ring-shaped reflector 24 separately from the driven roller, the disk surface of the driven roller may be colored and used as a reflector.

Further, as another embodiment, the driven roller 2 is provided with a member formed so that the adjacent segment becomes uneven on the boundary in the radial direction. Sensor to detect the unevenness of the surface of
The detected change in the unevenness may be output as a change in the output signal. For example, the driven roller 2 has
In FIG. 11A, a ring-shaped member is provided in which the white (W) portion becomes a peak portion and the black (B) portion becomes a valley portion. May be a contact sensor for detecting This unevenness can be provided on the disk surface of the ring-shaped member, or can be provided on the cylindrical surface of the ring-shaped member, and the contact sensor also has
The ring-shaped member can be installed at a position where the unevenness can be detected in accordance with the position where the unevenness is provided. This also enables the presence or absence of rotation of the driven roller 2 to be accurately transmitted to the determination means 9 (FIG. 1) as the presence or absence of a change in the output signal.

According to still another embodiment of the present invention, there is provided a printing apparatus including the paper jam detecting device according to any one of the above embodiments. The configuration of the printing device other than the paper jam detection device is the same as that of the known device, and a description thereof will be omitted. According to this printing device, since printing is not stopped by mistake due to slippage or the like,
The printing device can continue stable printing.

[0050]

According to the present invention, the stop of the rotation of the driven roller is not immediately judged as "paper jam", so that there is no possibility that the paper feed motor is stopped by mistake. In addition, the continuous state of the same state without signal change is measured as the number of continuous detections or the continuous time, and is compared with a preset reference value or reference time, and when it becomes the same value, it is determined that a “paper jam”. Thus, the stoppage of the rotation of the driven roller due to the temporary slip and the stoppage of the rotation of the driven roller due to the paper jam can be distinguished with high accuracy, and the correct determination of the paper jam can be performed. Further, the rotation of the driven roller is detected, and the rotation state is detected as a repetition of the state change of the output signal. When the state change of the signal is “none”, the state change is repeated every unit time. Since the state of the output signal is detected, the conveyance state is always detected, which also stops the rotation of the driven roller due to the temporary slip and the driven roller caused by the clogging of the print medium. Can be distinguished from the rotation stop of the print medium with high accuracy, so that it is possible to correctly determine whether the print medium is clogged.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an embodiment of a paper jam detection device of a printing apparatus according to the present invention.

FIG. 2 is a flowchart of paper jam detection according to the present invention.

FIG. 3 is a timing chart of paper jam detection according to the present invention.

FIG. 4 is a timing chart of a conventional paper jam detection.

FIG. 5 is a longitudinal sectional view showing a state where flat continuous paper is in contact with a driven roller.

FIG. 6 is a vertical cross-sectional view showing a state where continuous paper with a fold (peak) is in contact with a driven roller.

FIG. 7 is a vertical cross-sectional view showing a state in which continuous paper with a fold (valley) is in contact with a driven roller.

FIG. 8 is a perspective view showing creased continuous paper and a box in which it is stored.

FIG. 9 is a perspective view of a state in which the creased continuous paper is spread on a flat plane.

FIG. 10 is a perspective view showing a ring-shaped magnet and a rotation detector provided on a driven roller.

FIG. 11A is a perspective view showing a ring-shaped reflecting plate and a rotation detector provided on a driven roller, and FIG.
FIG. 3 is a block diagram illustrating a circuit configuration of a rotation detector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Continuous paper which is a printing medium 2 Follower roller 3 Axis 4 Fold 5, 6 Area where there is no signal change (temporary slip) 8 Rotation detector 9 Judgment means 10 Paper feed motor 11 Area of regular signal pattern 12, 13 Region where signal does not change (paper jam) 22 Ring magnet 24 Ring reflector 82 Hall element 84 Light emitting / receiving device

Claims (13)

[Claims] 1. A driven roller that rotates in contact with a print medium conveyed by a driving roller, and rotation detection that detects the rotation of the driven roller and detects the rotation state as a repetition of a change in the output signal. Means for receiving the output signal of the rotation detecting means, and when the state change of the signal is "absent", detecting the state of the output signal every unit time in which the state change is repeated, and continuously detecting the same state A print medium clogging detection device for a printing apparatus, comprising: a determination unit that determines “print medium clogging” when the integrated value of the number of times becomes equal to a preset reference value and stops conveyance of the print medium. 2. A driven roller that rotates in contact with a print medium conveyed by a driving roller, and rotation detection that detects rotation of the driven roller and detects the rotation state as a repetition of a change in the state of an output signal thereof. Means for receiving an output signal of the rotation detecting means, and when the state change of the signal is "present", printing is continued as it is, and when the state change is "absent", the state change is repeated per unit time. The state of the output signal is detected, and when the integrated value of the number of consecutive detections of the same state becomes the same as a preset reference value, it is determined that the print medium is clogged, and the conveyance of the print medium is stopped. A determination means for determining that a temporary slip has occurred and resetting the integrated value when the state change of the output signal becomes "present" before the integrated value becomes equal to the reference value; Equipment marking Media jam detection device. 3. The printing medium clogging detection device according to claim 1, wherein the reference value is variable. 4. A driven roller that rotates in contact with a print medium conveyed by a driving roller, and rotation detection that detects rotation of the driven roller and detects the rotation state as a repetition of a change in the output signal. Means, receiving the output signal of the rotation detecting means, when the state change of the signal is "absent", measures the duration of the state of "absence", the duration is a reference time preset A print medium clogging detection device for a printing apparatus, comprising: determination means for determining that the print medium has been clogged when the values become the same, and stopping conveyance of the print medium. 5. A driven roller that rotates in contact with a print medium conveyed by a driving roller, and rotation detection that detects the rotation of the driven roller and detects the rotation state as a repetition of a change in the output signal. Means, receiving the output signal of the rotation detecting means, if the state change of the signal is "present", continue printing as it is, if the state change is "absent", the duration of the "absent" state Is measured, and when the duration becomes the same as the preset reference time, it is determined that the printing medium is clogged and the conveyance of the printing medium is stopped, and before the duration becomes the same as the reference time. A print medium clogging detection device for a printing apparatus, comprising: determination means for determining "temporary slip" when the state change of the output signal becomes "present" and resetting the measurement of the duration. 6. The print medium clogging detection device according to claim 4, wherein the reference time is variable. 7. The printing apparatus according to claim 1, wherein a change in the state of the output signal when the driven roller is rotating normally occurs a plurality of times for one transport operation of the print medium. A printing medium clogging detection device for a printing device, characterized in that: 8. The printing medium according to claim 1, wherein the printing medium is conveyed by a stepping motor driven by a pulse signal, and the determining unit outputs the output of the rotation detecting unit for each step of the motor. A printing medium clogging detection device for a printing device, wherein the determination is made by taking in the state of a signal. 9. The print medium clogging detection device according to claim 1, wherein the print medium is continuous paper folded through a fold. 10. The rotation detecting means according to claim 1, wherein the rotation detecting means detects a change in a magnetic field, and outputs the detected change in the magnetic field as a state change of an output signal. And a magnet that rotates with the rotation of the driven roller, wherein the magnet is magnetized so that the magnetic field detected by the rotation detecting means changes with the rotation. Print media clogging detection device for the device. 11. The rotation detection device according to claim 1, wherein the rotation detection device includes a light-emitting device and a light-receiving device, and outputs a change in the amount of light received by the light-receiving device as a state change of an output signal. The driven roller includes a reflecting plate that rotates with the rotation of the driven roller, and the reflecting plate is arranged to reflect light from the light emitting unit and make the reflected light incident on the light receiving unit. A printing medium clogging detection device for a printing apparatus, wherein a portion that reflects light from the light emitting means is colored so that the reflectance of the light changes as the reflection plate rotates. 12. The method according to claim 1, wherein the rotation detecting means detects irregularities on the surface of the object, and outputs a change in the detected irregularities as a state change of an output signal. The roller includes a member that rotates with the rotation of the driven roller, and the member has a surface formed so that the rotation detecting unit detects a change in unevenness with the rotation. A printing medium clogging detection device for a printing device, characterized by comprising: 13. A printing apparatus comprising the print medium clogging detection device according to claim 1. Description: