JP2000344397A - Image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a normally conveyed recording medium from being handled as a separation delay jam. SOLUTION: In this image recorder 100B, a recording medium P electrostatically attracted to a photosensitive drum 101 is separated by a separating electrifier 107B. The recording medium P is detected by a sensor 110 arranged at a predetermined position X1 downstream of the separating electrifier 107B. A measuring means 112 measures a passage timing of the recording medium P at X1 based upon information of the sensor 110. A storing means 113 stores this passage timing. When a ratio of timings late from a reference value in a predetermined number (e.g. 100 counts) of timings stored in the storing means 113 exceeds a certain ratio (e.g. 70%), a control means 114 modifies a jam detection timing set at 500 ms after a register clutch OH (e.g. delay 5 ms).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image recording apparatus such as a copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art In an image recording apparatus such as a copying machine, a printer, and a facsimile, a recording medium moving in the main body of the image recording apparatus may adhere to members such as a photosensitive drum, a conveying belt and a recording head due to static electricity or the like. is there. In such a case, the recording medium is separated from members such as the photosensitive drum, the conveyance belt, and the recording head by using a separation unit or the like for electrically separating. This will be described with some specific examples.

<Conventional Example> FIG. 10 shows a schematic structure of an almost conventional electrophotographic image recording apparatus 100A.

[0004] Photosensitive drum 1 rotating clockwise
The laser light L emitted from the laser scanner 102 is irradiated on the surface 01. Thereby, the photosensitive drum 10
An electrostatic latent image is formed on 1, and the electrostatic latent image is visualized by the toner developing device 103. Note that the laser scanner 102 emits a laser beam L based on the document image read by the reader unit 104.

[0005] On the other hand, the recording mediums P stacked in a cassette (not shown) are fed. The stacked recording media P are sent out one by one in order from the uppermost recording media by a paper feed roller 105 rotating in a counterclockwise direction.

[0006] The recording medium P sent from the cassette is
The sheet is sent to the registration roller pair 106C in the rotation stopped state. Then, when the leading end of the recording medium P abuts the nip of the pair of registration rollers 106C to form a predetermined amount of loop, the movement of the recording medium P is stopped. Thereby, the recording medium P
Is corrected, and the image is recorded in the recording medium P in a correct posture.

The recording medium P whose skew has been corrected by the pair of registration rollers 106C is sent to the transfer section between the photosensitive drum 101 and the transfer charger 107A by the pair of registration rollers 106C that starts rotating at a predetermined timing. Can be Then, while the recording medium P passes through the transfer section, the toner image on the photosensitive drum 101 is transferred by the transfer charger 107A.

When the toner image is transferred, the recording medium P is electrostatically attracted to the photosensitive drum 101, but is separated from the photosensitive drum 101 by the separation charger 107B. Conventionally, the value of the current applied to the separation charger 107B is substantially constant.

After the transfer of the toner image is completed, the photosensitive drum 10
The recording medium P separated from 1 is sent to the fixing roller pair 108. Then, the toner image which has not been fixed is fixed by being heated and pressed while passing through the fixing nip of the fixing roller pair 108. The recording medium P after the fixing process is discharged onto a discharge tray (not shown) outside the apparatus.

<Conventional Example> FIG. 11 shows a schematic configuration of a main part of an electrophotographic image recording apparatus 200 of a conventional example.

The photosensitive drum 2 rotating clockwise.
A laser beam L emitted from a laser scanner (not shown) is irradiated on the surface 01. Thus, an electrostatic latent image is formed on the photosensitive drum 201, and the electrostatic latent image is visualized by the toner developing device 202.

On the other hand, the recording medium P is fed from a paper feed unit (not shown). The recording medium P fed from the paper feeding unit stops moving when a leading end of the recording medium P comes into contact with the nip of the registration roller pair 203C in the rotation stopped state to form a predetermined amount of loop. As a result, the skew state of the recording medium P is corrected, and the recording of the image on the recording medium P is performed in a correct posture.

The recording medium P, whose skew has been corrected by the registration roller pair 203C, is rotated counterclockwise by the registration roller pair 203C that starts rotating at a predetermined timing (endless belt made of resin). 2
It is sent to 04.

The recording medium P is sent to a transfer section between the photosensitive drum 201 and the transfer charger 205 in a state where the recording medium P is electrostatically attracted to the conveyor belt 204. put it here,
The recording medium P is electrostatically attracted to the transport belt 204 by an attraction charger 206 arranged near the start end of the transport belt 204. The toner image on the photosensitive drum 201 is transferred to the recording medium P passing through the transfer section.
5 transferred.

The recording medium P after the transfer of the toner image is
The sheet is separated from the conveyance belt 204 by a separation charger 207 disposed near the end of the conveyance belt 204 and sent to a fixing roller pair 208. Conventionally, the value of the current applied to the separation charger 207 is substantially constant. And
By heating and pressing while passing through the fixing nip of the fixing roller pair 208, the toner image in the unfixed state is fixed. The recording medium P after the fixing process is discharged onto a discharge tray (not shown) outside the apparatus.

By the way, in the above conventional example,
There is a case where separation of the recording medium P from the photosensitive drum 101 or separation from the transport belt 204 is not performed well. In such a case, a delay (separation delay jam) occurs in the conveyance of the recording medium P. If the recording medium P is left as it is, the recording medium P may move integrally with the photosensitive drum 101 or the transport belt 204.

For example, a conventional image recording apparatus 100A
When the above situation occurs, the photosensitive drum 10
The recording medium P that moves together with the recording medium 1 causes a problem such as damage to the cleaning member 109 for removing the toner remaining on the photosensitive drum 101 after the transfer.

When the above situation occurs in the conventional image recording apparatus 200, the recording medium P moving integrally with the transport belt 204 causes the transport belt 204 to move.
There is a problem that the cleaning member 209 for removing the toner adhering to the sheet is damaged.

In order to eliminate such inconveniences, the conventional image recording apparatuses 100A and 200 have
A measure is taken to monitor the separation delay jam of the recording medium P and immediately stop the entire operation when the separation delay jam occurs.

The image recording apparatus 100 of the conventional example described above.
In A and 200, the separation delay jam of the recording medium P is monitored as follows.

In the image recording apparatus 100A, information from a sensor 110 disposed at a predetermined position X1 downstream of the separation charger 107B is sent to a control means (CPU) 111 for monitoring a separation delay jam.

In the image recording apparatus 200, a sensor 21 disposed at a predetermined position X2 downstream of the separation charger 207 is provided.
Information from 0 is sent to the control means (CPU) 211 for monitoring the separation delay jam.

When the sensors 110 and 210 detect the recording medium P (there is a detection signal from the sensor) at the time of the jam detection, the control means 111 and 211 determine that the separation delay jam has occurred and stop all the operations. Let it.

Here, the jam detection timing is fixedly set at the design stage. Image recording device 100
A and the image recording apparatus 200, the registration motor pair 106A, 203C
Resist clutch 106B for transmitting the drive of 203A, 2
The jam detection timing is set after a lapse of a predetermined time from the time point when the clutch 03B is turned on. The jam detection timing is determined from the timing at which the recording medium P passes through the sensors 110 and 210. The timing at which the recording medium P passes the sensors 110 and 210 at the set speed is a predetermined time after the registration clutch is turned on, and the jam detection timing is a further predetermined time after that.
FIG. 12 shows the relationship between the sensor passage timing (Tmean) and the jam detection timing (Tjam).

FIG. 13 shows an example of a jam detection timing in the case of the image recording apparatus 100A. Here, the jam detection timing (Tjam) is set at a point in time when 500 ms has elapsed since the registration clutch was turned on. At this time, if the sensor 110 is High, the recording medium P has been detected, and it is determined that a separation delay jam has occurred. Also,
If the sensor 110 is Low, the recording medium P is not detected, and it is determined that there is no separation delay jam.

[0026]

However, the above conventional example in which the jam detection timing (Tjam) is fixed,
In the case of the image recording apparatuses 100A and 200, even if the recording medium P is properly separated from the photosensitive drum 101 and the transport belt 204 and is normally transported, it has not passed the sensors 110 and 210 before the jam detection timing. Is determined to be a separation delay jam, the entire operation is stopped, and a jam occurs.

Generally, the recording medium P is a sensor 110, 2
As shown in FIG. 12, the timing (Tmean) of passing through 10 tends to be delayed as the number of times of feeding increases. That is, the state is delayed from the state a to the state b. Therefore, when the jam detection timing (Tjam) is fixed, the recording medium P delayed to the state b
May not pass through the sensors 110 and 210 before the jam detection timing. In such a case, even the recording medium P that is normally conveyed is determined to be a separation delay jam.

In the case of the conventional image recording apparatuses 100A and 200 in which the current values applied to the separation chargers 107B and 207 are substantially fixed, the photosensitive drum 101
And the state of the transport belt 204, the current value may not be appropriate for separating the recording medium P from the photosensitive drum 101 or the transport belt 204. In such a case, the separation performance of the separation chargers 107B and 207 may be used. Decrease.

Accordingly, the present invention has been made in view of the above-described circumstances, and is intended to prevent a normally conveyed recording medium from being judged as a separation delay jam and performing unnecessary unnecessary jam processing. It is an object of the present invention to provide an image recording apparatus having the above configuration. It is another object of the present invention to provide an image recording apparatus in which the separating performance of the electrical separating means is not reduced.

[0030]

According to the present invention, there is provided an image recording apparatus for separating a moving recording medium attached to a member existing on a recording medium moving path from the member by using a separating means. Related to the device.

In order to achieve the above object, the present invention provides a recording medium detecting means for detecting a recording medium at a predetermined position downstream of the separating means, and a recording medium based on information detected by the recording medium detecting means. A passage timing measurement unit that measures a timing at which the passage timing has passed a predetermined position downstream of the separation unit, a passage timing storage unit that saves a passage timing measured by the passage timing measurement unit, and a passage timing storage unit that stores the passage timing. Control means for changing the jam detection timing based on the passing timing information.

For example, when the ratio of the timing value delayed from the reference timing value in the passage timing information of the predetermined number stored by the passage timing storage unit exceeds a certain ratio, Change the jam detection timing.

For example, the control unit changes the jam detection timing when the ratio of the separation delay jam exceeds a certain ratio in the passage timing information of a predetermined number stored in the passage timing storage unit. .

For example, the control means changes the jam detection timing when the total number of separation delay jams in the passage timing information stored in the passage timing storage means exceeds a predetermined number.

Further, the present invention has a notifying means controlled by the control means.

For example, when the changed jam detection timing exceeds the changed maximum value, the control means drives the notification means to display an error.

For example, when the separation delay jam continues a predetermined number of times, the control means drives the notification means to display an error.

For example, when the ratio of the separation delay jam exceeds a predetermined ratio, the control unit drives the notification unit to display an error.

For example, when the passage timing exceeds a predetermined value, the control means drives the notification means to display an error.

The present invention for achieving the above object relates to an image recording apparatus for separating a moving recording medium attached to a member existing on a recording medium moving path from the member by using an electric separating means.

In order to achieve the above object, the present invention provides a recording medium detecting means for detecting a recording medium at a predetermined position downstream of the electrical separating means, and information detected by the recording medium detecting means. Passing timing measuring means for measuring the timing at which the recording medium has passed a predetermined position downstream of the electrical separating means, passing timing storing means for storing the passing timing measured by the passing timing measuring means, and passing timing storing means And control means for changing a current value to be applied to the electrical separation means based on the passage timing information stored by the control means.

For example, when the ratio of the timing value delayed from the reference timing value in the passage timing information of the predetermined number stored by the passage timing storage unit exceeds a certain ratio, The current value is changed.

For example, the control means changes the current value when the ratio of the separation delay jam exceeds a predetermined ratio in the passage timing information of a predetermined number stored in the passage timing storage unit. .

For example, the control unit changes the current value when the total number of separation delay jams in the passage timing information stored in the passage timing storage unit exceeds a predetermined number.

Further, the present invention has a notifying means controlled by the control means.

For example, when the changed current value exceeds the maximum change value, the control means drives the notification means to display an error.

For example, when the separation delay jam continues a predetermined number of times, the control means drives the notification means to display an error.

For example, when the ratio of the separation delay jam exceeds a predetermined ratio, the control unit drives the notification unit to display an error.

For example, when the passage timing exceeds a predetermined value, the control means drives the notification means to display an error.

[0050]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 shows an almost entire schematic configuration of an electrophotographic image recording apparatus to which the present invention is applied.

The basic configuration of the image recording apparatus 100B is the same as that of the conventional image recording apparatus 100A. Therefore, here, only the differences (the invention part) will be described.

The image recording apparatus 100B takes measures to prevent the normally transported recording medium P from being handled as a separation delay jam. For this measure, the image recording apparatus 100B includes a recording medium detection unit (sensor) 110 and a passage timing measurement unit 11
2, the passage timing storage means 113, and the control means (C
PU) 114 and a notification unit 115.

The sensor 110 detects the recording medium P at a predetermined position X1 downstream of the separation charger 107B.

The passage timing measuring means 112 measures the timing at which the recording medium P has passed the predetermined position X1 downstream of the separation charger 107B based on the information detected by the sensor 110.

The passage timing storage unit 113 stores the passage timing measured by the passage timing measurement unit 112.

The control means 114 changes the jam detection timing for detecting the separation delay jam based on the passage timing information stored in the passage timing storage means 113. Here, the control unit 114 changes the jam detection timing as follows. This will be described with reference to FIG.

The timing (part b) which is slightly delayed from the reference timing (Tmean) set at the design stage in the information of a predetermined number of times (for example, 100 times) stored in the passage timing storage means 113. When the ratio exceeds 70% as indicated by the hatched portion, the jam detection timing Tjam-1 set based on the reference timing (Tmean) is set to Tjam-2 with a delay of 5 ms. To explain this with reference to FIG. 8, the changed jam detection timing Tjam-2 is the time when 505 ms has elapsed since the registration clutch was turned on. At this time, the control unit 114 determines whether the sensor 110 is High or Low.
Is checked, and if High, a separation delay jam is determined, and all operations are stopped.

As described above, when the jam detection timing is changed, the jam detection timing is also delayed with the delay of the recording medium P, so that the recording medium P is not separated from the photosensitive drum 101 but is integrally formed. When the recording medium P moves, a problem may occur that the separation delay jam is detected after the recording medium P reaches the cleaning member 109.

In order to prevent such a problem from occurring, here, the maximum delay value (T
max) is set, and when this value is exceeded, the control means 114 drives the notifying means 115 so that the notifying means 115
Show error above. Here, the maximum delay value (Tma
x) is the distance from the separation charger to the cleaning member ÷
Determined by the rotation speed of the photosensitive drum. However, there is a case where there is no other member than the cleaning member near the separation charger.

FIG. 3 shows a sequence relating to the change of the jam detection timing described above.

This sequence operates from the reference signal (S100) of the sensor 110. The sensor 110 becomes High and detects the recording medium P (S101). This allows
The passage timing measuring means 112 measures the passage timing T of the recording medium P (S102). Subsequently, the passage timing storage unit 113 stores the measured passage timing T (S103). Subsequently, the number of times of timing preservation (the number of times of sheet feeding) n is added (+1) (S104).

Subsequently, it is confirmed whether or not the measured passing timing T exceeds the reference value (Tmean) (S
105). As a result, if the passage timing T does not exceed the reference value, the process returns to S100.

On the other hand, if it exceeds the reference value, the number m of times exceeding the reference value is added (+1) (S10).
6). Next, it is checked whether or not the ratio of the number m of times exceeding the reference value in the predetermined number n (for example, 100 times) stored by the passage timing storage unit 113 exceeds 70% (S107). ). As a result, if the ratio of m to n does not exceed 70%, the process returns to S100.

On the other hand, if the ratio of m to n exceeds 70%, the jam detection timing Tjam is set to 5 m
s is delayed (S108). That is, Tjam-1 is changed to Tjam-2. Subsequently, it is confirmed whether or not the delayed jam detection timing Tjam exceeds the maximum delay value Tmax (S109). As a result, Tjam becomes T
If it does not exceed max, the process returns to S100.

On the other hand, if Tjam exceeds Tmax, the notifying means 115 is driven to display an error (S110).

Note that, here, the ratio of m to n is set to 70%, and the delay time of the jam detection timing Tjam is set to 5 ms, but these values are for the example image recording apparatus.

According to the present embodiment, when a delay occurs in the passage timing of the recording medium P passing the predetermined position X1, the jam detection timing for detecting the separation delay jam is changed accordingly, so that normal conveyance is performed. The recorded recording medium P is not treated as a separation delay jam. For this reason, unnecessary jam processing that is originally unnecessary is not required.

Maximum delay value Tm of jam detection timing
If the jam is detected and the jam detection timing Tjam exceeds the maximum delay value Tmax, the notification unit is driven to display an error, so that the operator can deal with the jam in advance.

<Second Embodiment> FIG. 4 shows another sequence relating to the change of the jam detection timing.

Steps S200 to S204 in the present sequence are the same as steps S100 to S104 in the sequence of FIG. 3, and thus description thereof will be omitted.

After S204, it is confirmed whether or not a separation delay jam has occurred (S205). This is confirmed by checking whether the passage timing exceeds the jam detection timing. As a result, if it is not a separation delay jam, the process returns to S200.

On the other hand, if it is a separation delay jam, the number of jams m is added (+1) (S206). continue,
The number m of separation delay jams in the predetermined number n (for example, 100 times) stored by the passage timing storage unit 113
Is determined whether or not the ratio exceeds 0.05% (S
207). As a result, the ratio of m to n is 0.05%
If not, the process returns to S200.

On the other hand, when the ratio of m to n exceeds 0.05%, the jam detection timing Tjam
(Tjam-1) is delayed by 10 ms (S208). Subsequently, it is determined whether or not the delayed jam detection timing Tjam exceeds the maximum delay value Tmax (S20).
9). As a result, when Tjam does not exceed Tmax, the process returns to S200.

On the other hand, if Tjam exceeds Tmax, the notifying means 115 is driven to display an error (S210).

In this case, the ratio of m to n is set to 0.05%, and the delay time of the jam detection timing Tjam is set to 10 ms, but these values are for the example image recording apparatus. .

According to the present embodiment, when a recording medium P having a separation delay jam exceeding a predetermined ratio exists in a predetermined number of recording media passing a predetermined position X1, a separation delay jam is detected. Since the detection timing is changed, the recording medium P normally conveyed is changed.
Is not treated as a separation delay jam. For this reason, unnecessary jam processing that is originally unnecessary is not required.

Maximum delay value Tm of jam detection timing
If the jam is detected and the jam detection timing Tjam exceeds the maximum delay value Tmax, the notification unit is driven to display an error, so that the operator can deal with the jam in advance.

<Third Embodiment> FIG. 5 shows a modification of the sequence of FIG.

Steps S300 to S306 in this sequence are the same as steps S200 to S206 in the sequence of FIG. 4, and steps S309 to S312 are the same as steps S207 to S210. Therefore, description of these will be omitted.

After S306, it is confirmed whether or not the separation delay jam is continuous (S307). Then, if it is continuous, it is confirmed whether or not it is continuous five times (S308).
If it is five consecutive times, the notification unit 115 is driven to display an error (S312).

Here, the separation delay jam is 5
An error is displayed when the number of consecutive times is consecutive, but the number of consecutive times is not limited to this.

When the separation delay jam occurs continuously,
A failure of the separation charger 107B, the drive roller of the photosensitive drum 101, or the like is considered. In the present embodiment, in order to cope with this, an error is displayed when the separation delay jam continues five times.

<Fourth Embodiment> FIG. 6 shows a modification of the sequence of FIG.

Steps S400 to S406 of this sequence are the same as steps S300 to S306 of the sequence of FIG. 5, and steps S408 to S411 are the same as steps S309 to S312. Therefore, description of these will be omitted.

Following S406, the predetermined number n (for example, 100 times) stored by the passage timing storage unit 113
It is checked whether the ratio of the number m of separation delay jams in minutes exceeds 10% (S407). If the ratio of m to n exceeds 10%, the notification unit 115 is activated. Then, an error is displayed (S411).

Note that, here, the ratio of m to n is 10%, but the ratio of m to n is not limited to this.

When the ratio of m to n exceeds about 10%, the separation charger 107B and the photosensitive drum 101
Of the drive roller or the like may be considered. In this embodiment, in order to cope with this, an error is displayed when the ratio of m to n exceeds 10%.

<Fifth Embodiment> FIG. 7 shows a modification of the sequence of FIG.

Steps S500 to S504 of this sequence are the same as steps S100 to S104 of the sequence of FIG. 3, and steps S506 to S511 are the same as steps S105 to S110. Therefore, description of these will be omitted.

Following S504, the passing timing T is set to 1
000 ms is checked (S50).
5) If the time exceeds 1000 ms, the notification means 11
5 is driven to display an error (S511).

Here, an error is displayed when the passing timing T exceeds 1000 ms.
The value of 1000 ms is not limited to this.

If the passage timing T exceeds a certain value, a failure of the separation charger 107B, the driving roller of the photosensitive drum 101, or the like is considered. In this embodiment, in order to cope with this, an error is displayed when the passage timing T exceeds 1000 ms.

<Sixth Embodiment> FIG. 8 shows another sequence applied to the image recording apparatus 100B of FIG.

This sequence is a sequence for preventing separation delay jam from occurring. As shown in FIG. 2, as the number of paper feeds increases, the passage timing tends to be delayed as in state b. One of the causes is that the current value I applied to the separation charger 107B is not appropriate. . Therefore, in this sequence, the current value I applied to the separation charger 107B is appropriately controlled to enhance the performance of separating the recording medium P from the photosensitive drum 101 so that the passage timing always becomes the state a. I do.

Steps S600 to S607 of this sequence are the same as steps S100 to S107 of the sequence of FIG. Therefore, description of these will be omitted.

As a result of the check in S607, if the ratio of m to n exceeds 70%, the separation charger 10
The current value I applied to 7B is changed.

Here, for example, if the separation charger 107B is a corona charger, it is known that if the peak current of the alternating current is changed, leakage will occur immediately.
The value to be changed is only DC current.

Further, for example, when the photosensitive drum 101 is made of amorphous silicon, it is known that if the current value is changed to the negative side, the recording medium P is easily separated, so that the current value of the separation charger 107B is set to the set value − Change to 10 μA.

When the photosensitive drum 101 is an OPC,
When the current value is changed to the positive side, the recording medium P is easily separated, so that the current value of the separation charger 107B is set to the set value
Change to 10 μA.

However, regardless of whether the photosensitive drum 101 is amorphous silicon or OPC, if the passing timing with a slight delay increases, the setting value of the separation charger 107B will be greatly changed. In this case, the change in the current of the separation charger 107B is ± 50 μm at the maximum, because it is considered that a leak or an image is not well formed on the recording medium.
A.

<Seventh Embodiment> FIG. 9 shows a modification of the sequence shown in FIG.

Steps S700 to S708 of this sequence are the same as steps S600 to S608 of the sequence of FIG. Therefore, description of these will be omitted.

After S708, it is checked whether or not the change current value I exceeds a preset maximum change value Imax (± 100 μA) (S709).
If it exceeds max, the notification unit 115 is driven to display an error (S710).

Note that, here, the maximum change value Imax
Is set to ± 100 μA, but the numerical value ± 100 μA is not limited to this.

When the current value I applied to the separation charger 107B exceeds a certain value, a failure of the separation charger 107B or the like is considered. In the present embodiment, in order to cope with this, a change maximum value Imax is set, and an error is displayed when the change current value I exceeds this.

In the sequences of FIGS. 8 and 9, the current value applied to the separation charger is changed when the ratio of m (the number of times of passage timing delay) to n exceeds 70%. Similar to a sequence such as 4th, m for n
When the ratio of (separation delay jam times) exceeds 0.05%, the current value applied to the separation charger may be changed. Further, in the sequence of FIG. 7, an error is displayed when the passage timing exceeds 1000 ms, but this may be performed in the sequence of FIG.

In each of the above embodiments, the change of the jam detection timing and the change of the current value applied to the separation charger are performed by the image recording apparatus itself (control means 114). It may be performed on an assist connected by a line. For example, in the case of the sequence shown in FIG. 3, the operator inputs (changes the timing) of S108. For example, in the case of the sequence of FIG. 8, the operator inputs (changes the current value) in S608.

In the above embodiments, when the ratio of m to n exceeds a predetermined ratio (70% or 0.05%), the jam detection timing is changed or applied to the separation charger. When the current value is changed, but the total number of m (separation delay jam times) exceeds a predetermined number (for example, 20 times) set in advance, the jam detection timing is changed or the separation charger is operated. The value of the applied current may be changed.

The present invention separates a moving recording medium adhered to a member (for example, a photosensitive drum, a conveyor belt, a recording head, etc.) existing on a recording medium moving path by static electricity or the like by using a separating means such as a charger. The image recording apparatus can be widely applied as long as it is used and separated from a member.

[0111]

As described above, according to the present invention,
Since the jam detection timing for detecting the separation delay jam is changed based on the passage timing information of the recording medium that has passed a predetermined position downstream of the separation unit that separates the recording medium from the member, the conveyance is performed normally. A recording medium that is present is not treated as a separation delay jam. For this reason, unnecessary jam processing that is originally unnecessary is not required.

Further, according to the present invention, the value of the current applied to the electrical separating means is changed based on the passage timing information of the recording medium having passed a predetermined position downstream of the electrical separating means for separating the recording medium from the member. As a result, the recording medium is properly separated by the electrical separating means. For this reason, the separating ability of the electrical separating means does not decrease.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a substantially entire configuration of an image recording apparatus to which the present invention is applied.

FIG. 2 is a diagram illustrating a change in a passage timing of a recording medium passing a predetermined position downstream of a separation charger and a change in a jam detection timing.

FIG. 3 is a flowchart showing a sequence (1) for changing jam detection timing.

FIG. 4 is a flowchart showing a sequence (2) for changing a jam detection timing.

FIG. 5 is a flowchart showing a sequence (3) for changing jam detection timing.

FIG. 6 is a flowchart showing a sequence (4) for changing jam detection timing.

FIG. 7 is a flowchart showing a sequence (5) for changing jam detection timing.

FIG. 8 is a flowchart showing a sequence (1) for changing a current value applied to the separation charger.

FIG. 9 is a flowchart showing a sequence (2) for changing a current value applied to the separation charger.

FIG. 10 is a conceptual diagram showing a substantially entire configuration of a conventional image recording apparatus.

FIG. 11 is a conceptual diagram showing a configuration of a main part of a conventional image recording apparatus.

FIG. 12 is a diagram showing a change in a passage timing of a recording medium passing a predetermined position downstream of the separation charger and a jam detection timing.

FIG. 13 is a timing chart showing an example of a jam detection timing.

[Explanation of symbols]

 Reference Signs List 101 photosensitive drum (member) 107B separation charger (separation unit, electrical separation unit) 110 sensor (recording medium detection unit) 112 passage timing measurement unit 113 passage timing storage unit 114 control unit 115 notification unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) G03G 21/00 510 G03G 21/00 372 F term (reference) 2C058 AB16 AC08 AE02 AE09 AF04 AF20 GB01 GB14 GB22 GB30 GB49 GB52 GE17 2H027 DA32.

Claims (14)

[Claims] 1. An image recording apparatus for separating a moving recording medium attached to a member existing on a recording medium moving path from the member by using a separating unit, wherein the recording medium is located at a predetermined position downstream of the separating unit. Recording medium detecting means for detecting the time, a passage timing measuring means for measuring the timing when the recording medium has passed a predetermined position downstream of the separating means, based on the information detected by the recording medium detecting means, the passing timing measuring means An image recording apparatus comprising: a passage timing storage unit that stores a measured passage timing; and a control unit that changes a jam detection timing based on the passage timing information stored by the passage timing storage unit. 2. The method according to claim 1, wherein the control unit is configured to determine whether the ratio of the timing value delayed from the reference timing value in the passage timing information of the predetermined number stored by the passage timing storage unit exceeds a certain ratio. 2. The image recording apparatus according to claim 1, wherein the jam detection timing is changed. 3. The control unit changes the jam detection timing when the ratio of the separation delay jam exceeds a predetermined ratio in the passage timing information of a predetermined number stored by the passage timing storage unit. The image recording apparatus according to claim 1, wherein: 4. The control means changes the jam detection timing when the total number of separation delay jams in the passage timing information stored in the passage timing storage means exceeds a predetermined number. The image recording device according to claim 1. 5. An image recording apparatus for separating a moving recording medium attached to a member present on a recording medium moving path from said member by using an electric separating unit, wherein a predetermined position downstream of said electric separating unit is provided. A recording medium detecting means for detecting a recording medium, and a passage timing measuring means for measuring a timing at which the recording medium has passed a predetermined position downstream of the electrical separating means, based on information detected by the recording medium detecting means, Passing timing storing means for storing the passing timing measured by the passing timing measuring means; controlling means for changing a current value applied to the electrical separating means based on the passing timing information stored in the passing timing storing means An image recording apparatus, comprising: 6. The control unit according to claim 1, wherein a ratio of a timing value delayed from a reference timing value in a predetermined number of pass timing information stored in said pass timing storage unit exceeds a predetermined ratio. The image recording apparatus according to claim 5, wherein the current value is changed. 7. The control unit changes the current value when the ratio of the separation delay jam exceeds a predetermined ratio in the passage timing information of a predetermined number stored by the passage timing storage unit. The image recording apparatus according to claim 5, wherein: 8. The method according to claim 1, wherein the control unit changes the current value when the total number of separation delay jams in the passage timing information stored in the passage timing storage unit exceeds a predetermined number. The image recording apparatus according to claim 5, wherein: 9. The image recording apparatus according to claim 1, further comprising a notifying unit controlled by said control unit. 10. The image recording apparatus according to claim 9, wherein the control unit drives the notification unit to display an error when the changed jam detection timing exceeds the maximum change value. 11. The image recording apparatus according to claim 9, wherein the control unit drives the notification unit to display an error when the separation delay jam continues a predetermined number of times. 12. The image recording apparatus according to claim 9, wherein the control unit drives the notification unit to display an error when the ratio of the separation delay jam exceeds a predetermined ratio. 13. The image recording apparatus according to claim 9, wherein the control unit drives the notification unit to display an error when the passage timing exceeds a predetermined value. 14. The image recording apparatus according to claim 9, wherein the control unit drives the notification unit to display an error when the changed current value exceeds the maximum change value.