JPH10258551A - Image recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent stagnation of a recording operation due to detection of jamming. SOLUTION: This apparatus comprises an upstream conveyance detecting sensor 9 that is provided at an upstream side of a conveying passage placed from a paper feed roller 3 to a transferring section 6 and detects a recording paper 1 moving at the upstream side of the conveying passage and a downstream conveyance detecting sensor 10 that is provided at a downstream side of the conveying passage placed from the transferring section 6 to a paper discharge roller 5 and detects the recording paper 1 moving at the downstream side of the conveying passage. When the downstream conveyance detecting sensor 10 dose not detect the recording paper 1 before the upstream conveyance detecting sensor 9 detects the rear edge of the recording paper 1 after passing of the top of the recording paper 1 is detected by the upstream conveyance detecting sensor 9 and the downstream conveyance detecting sensor 10, it is judged that jamming of the recording paper 1 occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for recording an image on a recording sheet being conveyed along a conveying path by a transfer method.

[0002]

2. Description of the Related Art Heretofore, as this type of image recording apparatus, there has been known an image recording apparatus which is built in a facsimile apparatus and records an image on recording paper by interposing a transfer sheet by a thermal transfer method. In this image recording apparatus, thermal transfer is performed by sandwiching a recording sheet and a transfer sheet between a platen roller and a thermal head in the middle of a transport path in which a recording sheet is transported from a paper feed roller to a discharge roller.

Further, in such an image recording apparatus, in order to control the conveyance of the recording paper, the conveyance path upstream from the paper feed roller to the platen roller and the conveyance path downstream from the platen roller to the paper discharge roller are controlled. Are provided with two sensors for detecting the presence or absence of a recording sheet. In particular, a sensor provided on the downstream side of the transport path is used to detect an abnormal transport state (hereinafter, referred to as “jam”) due to wrinkling of a recording sheet.

More specifically, the procedure of this jam detection will be described. The recording paper that has passed a sensor installed on the upstream side of the conveyance path is conveyed by a predetermined amount to a position between the platen roller and the thermal head. You. During this time, the recording paper is sandwiched together with the transfer sheet, and an image is recorded by thermal transfer. After passing through the platen roller, the recording sheet moves while maintaining a state of being in close contact with the transfer sheet while moving a predetermined distance. Here, the predetermined position at which the rear end of the recording sheet is peeled off from the transfer sheet is determined by performing measurement in advance. Therefore, until the trailing edge of the recording sheet reaches the predetermined peeling position, the sensor on the downstream side of the conveyance path is caused to detect the presence or absence of the recording sheet on the conveyance path to determine whether the conveyance state is normal. doing. While the sensor on the downstream side of the transport path detects that recording paper is present on the transport path, it is determined that the transport state is normal. On the other hand, if the sensor on the downstream side of the conveyance path detects that there is no recording sheet on the conveyance path until the rear end of the recording sheet reaches the predetermined peeling position, it is determined that a jam has occurred, and the recording operation is performed. Has been stopped.

[0005]

However, in the above-described conventional image recording apparatus, even if the rear end of the recording sheet is moved by a predetermined feed amount to a predetermined peeling position, the rear end of the recording sheet is already transferred by the transfer. In some cases, the sheet may be peeled off from the sheet and pass through a sensor downstream of the conveyance path. In such a case, there is a problem that the recording operation is stopped because it is determined that a jam is detected and the recording operation is stopped in spite of the normal conveyance state.

The present invention has been proposed in view of the above points, and has as its object to provide an image recording apparatus capable of preventing a stagnation of a recording operation due to jam detection.

[0007]

According to an aspect of the present invention, there is provided an image recording apparatus, comprising: An image recording apparatus provided with a transfer unit for transferring an image to a recording sheet, wherein the recording unit is provided on an upstream side of a transport path from the paper supply unit to the transfer unit and moves the recording sheet moving on the upstream side of the transport path. An upstream conveyance detection unit for detecting, a downstream conveyance detection unit provided at a downstream side of a conveyance path from the transfer unit to the paper discharge unit, and detecting a recording sheet moving on the downstream side of the conveyance path;
After the passage of the leading edge of the recording sheet is detected by the upstream transport detecting unit and the downstream transport detecting unit, the downstream transport detecting unit detects the recording sheet before the upstream transport detecting unit detects the passage of the trailing edge of the recording sheet. And a conveyance state determining means for determining that a failure has occurred in the conveyance of the recording paper when the detection is stopped.

According to this image recording apparatus, after the upstream conveyance detection means and the downstream conveyance detection means detect the passage of the leading end of the recording sheet, and before the upstream conveyance detection means detects the passage of the rear end of the recording sheet, If the downstream transport detecting means no longer detects the recording paper, the transport state determining means determines that a problem has occurred in the transport of the recording paper, so after the upstream transport detecting means detects the passage of the rear end of the recording paper, This eliminates the need for jam detection based on the feed amount, and eliminates erroneous jam detection by the downstream conveyance detection unit. Therefore, it is possible to prevent stagnation of the recording operation due to jam detection.

The image recording apparatus according to a second aspect of the present invention is the image recording apparatus according to the first aspect, wherein the upstream transport detecting means is located near the transfer means on the upstream side of the transport path. Is provided.

According to this image recording apparatus, in addition to the effect of the image recording apparatus according to the first aspect, since the upstream conveyance detecting means is provided near the transfer means on the upstream side of the conveyance path, the recording paper is provided. A long time until the trailing end is detected by the upstream conveyance detecting means can be secured long, and the time for detecting the jam is extended, so that the jam can be detected more reliably.

The image recording apparatus according to a third aspect of the present invention is the image recording apparatus according to the first or second aspect, wherein the transfer means is provided between a platen roller and a thermal head. The transfer sheet having an ink layer on its surface is sandwiched between the recording sheet and the ink is transferred to the recording sheet by heat generated by a thermal head.

According to this image recording apparatus, in addition to the effects of the image recording apparatus according to claim 1 or 2,
Since the transfer means transfers the ink on the transfer sheet to the recording paper by the heat generated by the thermal head, it is not necessary to detect a jam based on the feed amount immediately after the transfer between the transfer sheet and the rear end of the recording paper. It is possible to eliminate erroneous jam detection regardless of whether the transfer sheet and the recording sheet are in close contact with each other.

An image recording apparatus according to a fourth aspect of the present invention is the image recording apparatus according to any one of the first to third aspects, wherein the paper feeding unit and the paper discharging unit are
These are a feed roller and a discharge roller that are driven while adjusting the amount of rotation by a control motor.

According to this image recording apparatus, in addition to the effects of the image recording apparatus according to any one of the first to third aspects, the paper feed means and the paper discharge means each adjust the amount of rotation by a control motor. Since the paper feed roller and the paper discharge roller are driven while rotating, the amount of rotation of these rollers can be controlled to accurately convey the recording paper.

The control motor is preferably a stepping motor, but is not particularly limited thereto, and may be any motor that can control the amount of rotation.

Furthermore, an image recording apparatus according to a fifth aspect of the present invention is the image recording apparatus according to any one of the first to fourth aspects, wherein the upstream transport detecting means and the downstream transport detecting means comprise: Actuator-type sensors that output detection signals in accordance with contact / non-contact of the recording paper, respectively.

According to this image recording apparatus, in addition to the effects of the image recording apparatus according to any one of the first to fourth aspects, the upstream transport detecting means and the downstream transport detecting means each provide contact / recording of recording paper. Since the sensor is an actuator type sensor that outputs a detection signal in response to non-contact, a detection signal is output from this sensor according to the presence or absence of a recording sheet on the transport path. It is possible to reliably determine whether or not the vehicle has passed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a side sectional view of an image recording apparatus according to the present invention. The image recording apparatus shown in FIG. 1 is a thermal transfer type image recording apparatus incorporated in a facsimile apparatus. The image recording apparatus includes a storage section 2 for storing a recording sheet 1, and a feeding section for drawing the recording sheet 1 from the storage section 2 into a transport path. A paper roller 3, a paper discharge roller 5 for sending the recording paper 1 sent via the transport path to a discharge section 4, and a transfer section disposed in the middle of a transport path between the paper supply roller 3 and the paper discharge roller 5 6, a conveyance roller 8 for feeding the transfer sheet 7 to the transfer unit 6, an upstream conveyance detection sensor 9 for detecting the presence or absence of the recording sheet 1 on the upstream side of the conveyance path from the paper supply roller 3 to the transfer unit 6, and a discharge from the transfer unit 6. At the downstream side of the transport path to the roller 5, the recording paper 1
It has a downstream transport detection sensor 10 for detecting the presence / absence of an image and a control unit described later.

The paper feed roller 3 rotates in accordance with the step angle of a stepping motor (not shown), and its rotation operation is controlled by a control unit described later, so that the recording paper 1 in the storage unit 2 is pressed against the guide plate 3a. And feeds out the drawn recording paper 1 to the downstream side along the transport path.

The paper discharge roller 5 rotates in accordance with the step angle of a stepping motor (not shown), and its rotation operation is controlled by a control unit described later, and the recording paper 1 sent from the upstream side of the transport path is divided into two sheets. The recording paper 1 is grasped in such a manner as to be sandwiched between the rollers, and the grasped recording paper 1 is sent out to the discharge unit 4.

The transfer section 6 includes a paper feed roller 3 between the platen roller 6a and the thermal head 6b along the conveyance path.
The recording paper 1 sent out from the transfer sheet 7 and the transfer sheet 7 conveyed by the conveyance rollers 8 are sandwiched, and transfer is performed by applying heat from the thermal head 6b to the sandwiched portion. By this thermal transfer, the ink layer formed on the surface of the transfer sheet 7 is melted, and the melted ink is transferred onto the recording paper 1 to record an image. The platen roller 6a is configured to be driven by a stepping motor (not shown), like the paper feed roller 3 and the like. The transport roller 8 is composed of two rollers for sending and winding the transfer sheet 7. The transport roller 8 has a smaller rotation amount per one step angle than the paper discharge roller 5, so that the transfer amount of the transfer film 7 with respect to the recording paper 1 is suppressed to ensure the transfer of the ink.

The upstream transport detection sensor 9 is an actuator type sensing device that outputs an on / off detection signal to a control unit described later according to the contact / non-contact of the recording paper 1. As shown in FIG. 1, when the recording paper 1 that has moved along the transport path from the paper feed roller 3 comes into contact with the upstream transport detection sensor 9, the upstream transport detection sensor 9 rotates in the transport direction (in a virtual line). Posture), the passage of the recording paper 1 is detected, and an ON operation detection signal is output. Recording paper 1
Is in a non-contact state, that is, when it is not passing through, the upstream transport detection sensor 9 outputs a detection signal of an OFF operation.

The downstream conveyance detection sensor 10 is an actuator type sensing device that outputs an on / off detection signal to a control unit described later according to the contact / non-contact of the recording paper 1. As shown in FIG. 1, the recording sheet 1 that has moved from the transfer unit 6 along the conveyance path is detected by the downstream conveyance detection sensor 1.
When it comes into contact with 0, the downstream conveyance detection sensor 10 rotates in the conveyance direction (the posture indicated by the imaginary line), detects passage of the recording paper 1, and outputs an ON operation detection signal. When the recording paper 1 is in a non-contact state, that is, when the recording paper 1 is not passing through, a detection signal of an OFF operation is output from the downstream conveyance detection sensor 10.

FIG. 2 is a circuit block diagram showing a control section of a facsimile apparatus incorporating the image recording apparatus of FIG. 1, and this control section controls other functions of the facsimile apparatus together with the image recording apparatus. Things.

As shown in the figure, the control unit comprises a CPU 21,
NCU 22, RAM 23, modem 24, ROM 25, E
EPROM 26, gate array 27, codec 28,
And a DMAC 29. CPU21, NCU
22, RAM 23, modem 24, ROM 25, EEPROM
The OM 26, the gate array 27, the codec 28, and the DMAC 29 are mutually connected by a bus line.
The bus lines include an address bus, a data bus, and a control signal line. The gate array 27 includes a reading unit 31,
The recording unit 32, the operation unit 33, and the display unit 34 are connected. The NCU 22 is connected to a telephone line 41 as an example of a communication line.

The CPU 21 controls the entire facsimile machine. The NCU 22 is connected to the telephone line 41 and performs network control. The RAM 23 stores various data. The modem 24 modulates and demodulates transmission / reception data. ROM
Reference numeral 25 stores various programs and the like. EEP
The ROM 26 stores various data and flags.
The gate array 27 functions as an input / output interface of the CPU 21. The codec 28 encodes transmission facsimile data and the like. DMAC 29
Data is written to and read from M23. The reading unit 31 performs a reading process of a read document. The recording unit 32 includes the paper feed roller 3, the paper discharge roller 5, the transfer unit 6, the transport roller 8, the upstream transport detection sensor 9, and the downstream transport detection sensor 10, and these devices are controlled by the CPU 21. The operation unit 33 includes a key switch group and the like,
Outputs a signal according to the operation of the user. The display unit 34
Various displays are performed under the control of the CPU 21.

More specifically, when the recording sheet 1 is moved along the transport path and the transfer is performed in the transfer section 6,
The CPU 21 drives the paper feed roller 3, the paper discharge roller 5, the transfer unit 6, and the transport roller 8 according to the detection signals output from the upstream transport detection sensor 9 and the downstream transport detection sensor 10 to perform recording. The conveyance of the sheet 1 is controlled.

Further, the point will be described.
Reference numeral 21 denotes a downstream conveyance detection sensor after the upstream conveyance detection sensor 9 and the downstream conveyance detection sensor 10 detect the passage of the leading end of the recording sheet 1 and before the upstream conveyance detection sensor 9 detects the passage of the rear end of the recording sheet 1. If the recording paper 10 stops detecting the recording paper, it is determined that a jam has occurred at the position of the downstream conveyance detection sensor 10. When determining that a jam has occurred, the CPU 21 stops the sheet feeding roller 3 and the like, stops the recording operation, and displays a warning on the display unit 34 that a malfunction has occurred. That is, the CPU 21
Implements a conveyance state determination unit that detects occurrence of a malfunction.

Next, the essential points of the operation of the image recording apparatus thus configured will be described with reference to FIG.

FIG. 3 is a flowchart showing the procedure of the recording process of the image recording apparatus. As shown in FIG. 3, when the recording process is started, the CPU 21 controls the paper feed roller with a predetermined rotation amount. 3, the recording paper 1 in the storage unit 2 is fed onto the transport path (S
1). Here, the predetermined rotation amount for rotating the paper feed roller 3 is stored in the ROM 25 in association with the step angle of the stepping motor that drives the paper feed roller 3.

After the paper feed roller 3 has been rotated a predetermined time, the CPU 21 determines whether or not a detection signal of an ON operation has been output from the upstream conveyance detection sensor 9 (S2). That is, it is determined whether the leading edge of the recording sheet 1 has contacted the upstream conveyance detection sensor 9 and passed the position of the upstream conveyance detection sensor 9.
U21 judges.

The leading edge of the recording paper 1 is detected by the upstream conveyance detecting sensor 9.
(S2: YES), the CPU 21
The transfer sheet 7 is conveyed to the transfer unit 6 by rotating the platen roller 6a and the conveyance roller 8 (S
3).

At the same time, the CPU 21
Is rotated by a predetermined amount of rotation (S
4) The leading end of the recording sheet 1 is moved to a position slightly passing through a position sandwiched between the platen roller 6a and the thermal head 6b, and is adjusted to the transfer start position (S5). Here, the predetermined rotation amount for rotating the paper feed roller 3 is stored in the ROM 25 in association with the step angle of the stepping motor that drives the paper feed roller 3.

Subsequently, when the leading end of the recording sheet 1 is aligned with the transfer start position, the CPU 21 starts the transfer processing in the transfer section 6 (S6). In this transfer process, the recording paper 1 is fed line by line to transfer the image.

Shortly after the transfer is started, the CPU 21
After the recording paper 1 is moved by a predetermined feed amount by the platen roller 6a or the like, the downstream conveyance detection sensor 10
It is determined whether or not a detection signal of the ON operation has been output from (S7). That is, the CPU 21 determines whether or not the leading end of the recording sheet 1 has contacted the downstream conveyance detection sensor 10 and passed the position of the downstream conveyance detection sensor 10. Also in this case, the predetermined feed amount by the platen roller 6a or the like is stored in the ROM 25 in association with the step angle of the stepping motor that drives the platen roller 6a.

The leading edge of the recording paper 1 is the downstream conveyance detection sensor 1
When passing through the position of 0 (S7: YES), the CPU 21
Moves the recording paper 1 by a predetermined feed amount, and then rotates the discharge roller 5 (S8). At this time,
When the leading end of the recording sheet 1 is moved to a position between the two discharge rollers 5, the leading end of the recording sheet 1 is sandwiched between the sheet discharging rollers 5 and is discharged to the discharge unit 4. Also in this case, the predetermined feed amount is stored in the ROM 25 in association with the step angle of the stepping motor that drives the platen roller 6a.

After rotating the discharge roller 5, the CPU 21
Is a state in which the downstream conveyance detection sensor 10 detects the passage of the recording paper, that is, when the detection signal of the ON operation is output from the downstream conveyance detection sensor 10, the detection signal of the OFF operation is output from the upstream conveyance detection sensor 9. It is determined whether or not the output has been made (S9). That is, the CPU 21 determines whether or not the trailing edge of the recording sheet 1 has separated from the upstream conveyance detection sensor 9 and is out of contact, and has passed the position of the upstream conveyance detection sensor 9.
Judge. Here, in a normal state in which the recording sheet 1 is moved and transferred line by line, the upstream conveyance detection sensor 9
In this state, both the downstream conveyance detection sensor 10 and the downstream conveyance detection sensor 10 output a detection signal of the ON operation.

The trailing end of the recording sheet 1 is the upstream conveyance detection sensor 9
(S9: YES), the CPU 21
After terminating the transfer process and rotating the discharge roller 5 by a predetermined rotation amount, it is determined whether there is any data waiting for the recording process (S10), and if there is no data waiting for the recording process (S10: YES). ), End this routine.

If there is data waiting for the recording process in S10 (S10: NO), the CPU 21 returns to the process in S1 and executes the main routine again.

In S9, when the detection signal of the ON operation is output from the upstream conveyance detection sensor 9, that is, when the rear end of the recording sheet 1 has not yet passed the position of the upstream conveyance detection sensor 9 (S9: NO) ), The CPU 21 proceeds to S6
Returning to the processing of (1), the transfer processing of one line is performed.

In step S7, when the detection signal of the OFF operation is output from the downstream conveyance detection sensor 10, that is, even though the recording paper 1 is detected to be passing by the upstream conveyance detection sensor 9, wrinkle breakage or the like occurs. When the recording sheet 1 is not in contact with the downstream conveyance detection sensor 10 and is in an abnormal conveyance state due to the occurrence of a jam due to (S7: N
O), as a jam warning process, the CPU 21 stops the sheet feeding roller 3 and the like, stops the recording operation,
A warning is displayed on the display unit 34 indicating that a malfunction has occurred (S11).

After the jam warning process, if the recording paper 1 causing the malfunction by the user or the like is removed from the transport path and it is determined that the jam has been cleared based on the state of the detection signal (S12: YES), The CPU 21 executes S1
And the main routine is executed again.

If the jam has not yet been cleared (S12: NO), the CPU 21 returns to the process of S11 and enters a standby state until the jam is cleared.

In S2, when the detection signal of the OFF operation is output from the upstream conveyance detection sensor 9, that is, when the leading end of the recording sheet 1 has not passed the position of the upstream conveyance detection sensor 9 yet (S2: NO). The CPU 21 shifts to the process of S11 and stops the sheet feeding roller 3 and the like,
The recording operation is stopped, and a warning is displayed on the display unit 34 indicating that a malfunction has occurred.

The CPU 21 executing the main routine of the recording process as described above outputs the signals from the upstream conveyance detection sensor 9 or the downstream conveyance detection sensor 10 until the rear end of the recording sheet 1 passes the upstream conveyance detection sensor 9. The occurrence of a jam is determined based on the on / off operation state of the detected signal.

Further, the recording sheet 1 and the transfer sheet 7 immediately after the transfer between the platen roller 6a and the thermal head 6b are moved in close contact with each other for a short distance, and
Thereafter, the recording sheets 1 are separated from each other, but if the contact state is prolonged, the recording sheet 1 is rolled up in the transport direction of the transfer sheet 7, thereby causing a jam due to wrinkling. CP
U21 detects the occurrence of this jam before the trailing edge of the recording sheet 1 passes through the upstream conveyance detection sensor 9.

According to such an image recording apparatus, after the upstream conveyance detection sensor 9 and the downstream conveyance detection sensor 10 detect the passage of the leading end of the recording paper 1, the upstream conveyance detection sensor 9 sets the rear end of the recording paper 1. If the downstream conveyance detection sensor 10 does not detect the recording paper 1 before detecting the passage of the recording paper 1, it is determined that a jam has occurred in the recording paper 1. Is detected, the need for jam detection based on the predetermined feed amount of the platen roller 6a is eliminated, and erroneous jam detection by the downstream conveyance detection sensor 10 is also eliminated. Stagnation can be prevented.

[0049]

As described above, according to the image recording apparatus of the first aspect of the present invention, after the upstream conveyance detecting means and the downstream conveyance detecting means detect the passage of the leading end of the recording paper, the upstream conveyance is performed. If the downstream conveyance detection means does not detect the recording paper before the detection means detects the passage of the rear end of the recording paper, the conveyance state determination means determines that a problem has occurred in the conveyance of the recording paper. After the means detects that the trailing edge of the recording paper has passed, the need for jam detection based on the feed amount is eliminated, and erroneous jam detection by the downstream conveyance detection means is eliminated, so that the recording operation is stalled due to jam detection. Can be prevented.

According to the image recording apparatus of the second aspect of the invention, in addition to the effect of the image recording apparatus of the first aspect, in addition to the effect of the upstream transportation detecting means, the upstream transportation detecting means is provided near the transfer means on the upstream side of the transportation path. , The time until the trailing edge of the recording sheet is detected by the upstream conveyance detecting means can be secured long, and the time for detecting the jam is extended, so that the jam can be more reliably detected. Can be detected.

According to the image recording apparatus of the third aspect of the invention, in addition to the effects of the image recording apparatus of the first or second aspect, in addition to the effect of the transfer means, the transfer sheet is generated by the heat generated by the thermal head. Is transferred to the recording paper, eliminating the need for jam detection based on the feed amount of the transfer sheet and the trailing edge of the recording paper immediately after the transfer. Regardless of the above, erroneous jam detection can be eliminated.

According to the image recording apparatus of the invention described in claim 4, in addition to the effects of the image recording apparatus according to any one of claims 1 to 3, the paper feeding means and the paper discharging means are provided. Since the paper feed roller and the paper discharge roller are driven while adjusting the amount of rotation by the control motor, the amount of rotation of these rollers can be controlled to convey the recording sheet accurately.

Further, according to the image recording apparatus of the invention described in claim 5, in addition to the effects of the image recording apparatus according to any one of claims 1 to 4, in addition to the upstream conveyance detecting means and the downstream conveyance detection. Since the means is an actuator type sensor that outputs a detection signal according to the contact / non-contact of the recording paper, the detection signal is output from this sensor according to the presence or absence of the recording paper on the transport path. Based on this detection signal, it can be reliably determined whether or not the recording paper has passed.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an image recording apparatus according to the present invention.

FIG. 2 is a circuit block diagram showing a control unit of a facsimile apparatus incorporating the image recording apparatus of FIG.

FIG. 3 is a flowchart showing a procedure of a recording process of the image recording apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording paper 3 Paper feed roller 5 Discharge roller 6a Platen roller 6b Thermal head 7 Transfer sheet 9 Upstream conveyance detection sensor 10 Downstream conveyance detection sensor

Claims (5)

[Claims] 1. An image recording apparatus comprising: a transfer unit for transferring an image onto a recording sheet in a conveyance path along which a recording sheet is conveyed from a sheet feeding unit to a sheet discharging unit. An upstream conveyance detecting means for detecting a recording sheet moving on the upstream of the conveying path, and an upstream conveying detecting means for detecting a recording sheet moving on the upstream of the conveying path; and a downstream of the conveying path from the transferring means to the paper discharging means. And a downstream conveyance detecting means for detecting the recording paper moving on the downstream side of the conveyance path; and after detecting the passage of the leading end of the recording paper by the upstream conveyance detecting means and the downstream conveyance detecting means, the upstream conveyance detecting means If the downstream conveyance detecting means does not detect the recording paper before detecting the passage of the trailing edge of the recording paper, the conveyance state which determines that a trouble has occurred in the conveyance of the recording paper. An image recording apparatus comprising: a state determination unit. 2. The image forming apparatus according to claim 1, wherein the upstream transport detecting unit is provided near the transfer unit on an upstream side of the transport path.
The image recording device according to claim 1. 3. The transfer means sandwiches a transfer sheet having an ink layer on its surface and the recording paper between a platen roller and a thermal head, and transfers the ink to the recording paper by heat generated by the thermal head. The image recording apparatus according to claim 1 or 2. 4. The paper feeding device and the paper discharging device according to claim 1, wherein the paper feeding device and the paper discharging device are a paper feeding roller and a paper discharging roller that are driven while adjusting a rotation amount by a control motor, respectively. Image recording device. 5. The sensor according to claim 1, wherein each of the upstream conveyance detection unit and the downstream conveyance detection unit is an actuator type sensor that outputs a detection signal in accordance with contact / non-contact of the recording sheet. An image recording apparatus according to any one of claims 1 to 3.