KR100545949B1 - Image Recording Device - Google Patents

Abstract

When the drive source 7 for conveying a paper conveyance means, the platen drive source 15 for rotationally driving a platen roller, and the required conveyance amount of recording paper are more than a predetermined quantity, or the paper thickness of a recording paper is more than predetermined thickness, The platen drive source 15 is operated during the operation of the paper conveyance drive source 7, and the paper conveyance drive source 7 is operated when the required conveyance amount of the recording paper is less than the predetermined amount or the paper thickness of the recording paper is less than the predetermined thickness. The platen motor control MPU 32 which stops the platen drive source 15 in the middle was provided.

Recording head, platen roller, motor control MPU, drive source control means for platen

Description

Image Recording Device

1 is a schematic side view of a main portion of an impact printer as one example of the image recording apparatus of the present invention.

Fig. 2 is a schematic plan view of the main portion of the impact printer shown in Fig. 1;

Fig. 3 is a sectional view seen from the arrow direction A-A in Fig. 2;

4 is a schematic circuit block diagram of the impact printer shown in FIG.

Fig. 5 is a flowchart for explaining the control processing procedure of the platen drive source by the platen motor control MPU shown in Fig. 4;

Fig. 6 is an explanatory diagram for explaining the relationship between the rotation operation of the output shaft of the drive source for conveying paper and the rotation operation of the output shaft of the drive source for platen;

Fig. 7 is a flowchart for explaining the control processing procedure of the platen drive source by the platen motor control MPU in another embodiment.

<Explanation of symbols for the main parts of the drawings>

1: recording head

2: platen roller

3: recording paper

5: upper tractor

6: lower tractor

7: drive source for conveying paper

8: stepless belt

15: driving source for platen

24: electronic clutch

31: MPU for paper conveying motor control

32: MPU for platen motor control

33: parent MPU

34: operator panel

The present invention is, for example, a dot impact printer, such as a dot impact printer, rotates the drive source for conveying paper for driving the conveying means for intermittently conveying the recording sheet in a predetermined direction in accordance with the progress of recording by the recording head, and the platen roller It relates to an image recording apparatus having a platen drive source for driving independently of each other.

Generally, in an image recording apparatus using a platen roller, since the gap between the recording surface and the recording head of the recording paper attached to the platen roller is small, a portion having a thick paper thickness such as a stepped medium or a paper stapler paper, etc. In the case of this existing recording paper, the recording paper may be jammed and torn between the recording head and the platen roller.

For this reason, the motor which conveys a recording paper and the motor which rotates a platen roller are jointly used, and this motor rotates a platen roller through a belt, and utilizes the sliding between a belt and a platen roller, The structure which prevents damage is employ | adopted.

However, in the case of adopting such a configuration, in a high-speed recordable image recording apparatus such as a dot impact printer when the recording operation and the paper conveying operation are alternately repeated as a general printing operation, the time required for conveying the paper is extremely short. Even if it stops, the platen roller does not stop due to the inertia force, and as a result, the platen roller rotates during recording by the recording head, resulting in a significant deterioration in printing quality.

In order to prevent such deterioration of printing quality, there existed a structure which prints with the platen roller fixed without rotating in a high speed recordable image recording apparatus like a dot impact printer. In this image recording apparatus, damage to the recording sheet is prevented by widening the gap between the recording head and the platen roller.

However, in such a configuration, various drawbacks arise due to the wide gap between the recording head and the platen roller. For example, when such a configuration is adopted in a dot impact printer, since the gap between the recording head and the platen roller is wide, the stroke amount of the head pin becomes larger than the prescribed value, the base of the head pin wears down, and the lifespan decreases. The operation rate and the reliability of the apparatus are deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is capable of preventing damage to the recording paper without widening the gap between the recording head and the platen roller, and at the same time, a factor caused by the delay in restoring the quiet state of the platen roller due to the inertia force. An object of the present invention is to provide an image recording apparatus capable of preventing deterioration of quality.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the following technical means are calculated | required by this invention.

According to a first aspect of the present invention, there is provided an image recording apparatus having a recording head, a platen roller, and a conveying means for conveying the recording sheet intermittently in a predetermined direction in a predetermined direction, comprising: a drive source for conveying a sheet for driving the conveying means; When the platen drive source for rotating the rollers and the required conveyance amount of the recording paper is more than the predetermined amount or the paper thickness of the recording paper is more than the predetermined thickness, the platen drive source is operated during the operation of the paper conveyance drive source, When the conveyance amount is less than the predetermined amount or the paper thickness of the recording sheet is less than the predetermined thickness, there is provided an image recording apparatus comprising platen drive source control means for stopping the platen drive source during operation of the drive source for conveying paper.

The recording paper may be cut paper or continuous paper.

As the recording method by the recording head, an impact method, a thermal transfer method, or the like can be adopted, but is not limited to these.

A stepping motor may be employed as the drive source for conveying paper and the drive source for platen, but is not limited thereto.

The drive source control means for the platen can be realized by a CPU (Central Processing Unit) that operates based on a predetermined program, but is not limited thereto. The platen drive source control means controls the platen drive source based on either the required conveyance amount of the recording sheet and the sheet thickness of the recording sheet.

According to a preferred embodiment, the platen drive source control means stops the operation of the platen drive source before the sheet conveyance drive source stops operating when the platen drive source is operated.

According to a second aspect of the present invention, there is provided an image recording apparatus having a recording head, a platen roller, and a conveying means for conveying recording paper intermittently in a predetermined direction in a predetermined direction, comprising: a drive source for conveying a sheet for driving the conveying means; A platen drive source which starts the operation of the platen drive source in accordance with the start of the operation of the platen drive source and the paper conveyance drive source, and stops the operation of the platen drive source before the operation stop of the paper transfer drive source. There is provided an image recording apparatus comprising a control means.

According to a preferred embodiment, the drive source control means for the platen has a time from when the platen drive source stops operating to when the paper transfer drive source stops operating in proportion to the required conveyance of the recording paper or inversely proportional to the paper thickness of the recording paper. The drive source for the platen is controlled.

The time from the operation stop point of the platen drive source to the operation stop point of the paper transfer drive source may be continuously varied or stepwise depending on the required conveyance amount of the recording paper or the paper thickness of the recording paper.

According to another preferred embodiment, the drive source control means for the platen has a conveying speed of the recording paper by the platen roller being less than or equal to the conveying speed of the recording paper by the conveying means, and the required conveyance amount of the recording paper or the paper thickness of the recording paper. The drive source for the platen is controlled to be proportional.

The conveyance speed of the recording sheet by the platen roller may be continuously varied or may be varied stepwise according to the required conveyance amount of the recording sheet or the sheet thickness of the recording sheet.

According to another preferred embodiment, there is provided locking means for preventing rotation of the platen roller when the drive source for conveying paper is not in operation.

An electronic clutch can be employed as the locking means, but is not limited thereto.

According to another preferred embodiment, there is provided locking means for preventing rotation of the platen roller when the drive source for the platen is not in operation.

According to another preferable embodiment, the control operation by the platen drive source control means is prohibited based on the instruction | indication operation by a user, and it is provided with the forced control means which controls the operation of the platen drive source according to an instruction operation.

According to the present invention, the platen roller is switched in accordance with the required conveyance amount of the recording paper or the paper thickness of the recording paper, or the operation of the platen drive source is stopped before the operation stop time of the drive source for conveying the paper. It is possible to prevent damage to the recording paper without widening the gap between the head and the platen roller, and to prevent deterioration in print quality due to the delay of the quiet state recovery of the platen roller due to the inertia force.

That is, when the required conveyance amount of the recording paper is small or when the paper thickness of the recording paper is thin, there is no possibility that the recording paper will be damaged even if the platen roller is not rotated. Therefore, the platen roller is not rotated. Thereby, deterioration of printing quality resulting from the quiet state recovery delay of a platen roller can be prevented. In addition, if the operation of the platen drive source is stopped before the operation stop of the paper conveyance drive source, the quiet state recovery time of the platen roller can be sufficiently secured. Deterioration can be prevented. In addition, since the gap between the recording head and the platen roller does not need to be widened as in the case where the platen roller is always fixed, the gap between the recording head and the platen roller, such as damage to the head pin, is caused by the impact printer. The flaw can be avoided.

In addition, if the platen roller is prevented from being rotated by the locking means when the drive source for conveying paper is not in operation, the platen roller is not rotated by the impact at the time of recording by the recording head. Can be kept even better.

In addition, when the platen driving source is not in operation, the rotation of the platen roller by the locking means can further reduce the quiet state recovery time of the platen roller, so that the printing quality can be better maintained. .

Other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described concretely with reference to drawings.

Fig. 1 is a schematic side view of the main portion of an impact printer as an example of the image recording apparatus of the present invention, wherein the gap between the recording head 1 and the platen roller 2 is a conveyance path of recording paper 3 made of continuous paper, and ink. The conveyance path of the ribbon 4 is located. The recording sheet 3 is conveyed in the direction of the arrow by the upper tractor 5 and the lower tractor 6. The upper tractor 5 and the lower tractor 6 are rotated via the endless belt 8 and the pulley 7a attached to the output shaft of the paper conveying drive source 7 by a paper conveying drive source 7 composed of a stepping motor. Driven. The endless belt 8 is tensioned by the tension roller 9.

Fig. 2 is a schematic plan view of the main portion of the impact printer shown in Fig. 1, and Fig. 3 is a sectional view seen from the direction of the arrow AA in Fig. 2, wherein the recording head 1 is linear to reciprocate along the supporting rod 11; It is attached to the shuttle 12. Although not shown in the recording head 1, 14 head blocks having 12 head pins in total in the main scanning direction, 24 in the sub scanning direction and 288 head pins in total are provided along the main scanning direction.

A pulley 14 is attached to one end of the rotation shaft 13 of the platen roller 2, and the pulley 14 and the pulley fixed to the output shaft 16 of the platen drive source 15 constituted of a stepping motor. The endless belt 18 is wound up over (17). The endless belt 18 is tensioned by the tension roller 19.

The pair of upper tractors 5 are attached to the rotating shaft 21 and convey the recording paper 3 using the conveying holes 22 formed at predetermined intervals at both ends in the width direction of the recording paper 3. The pair of lower tractors 6 are attached to the rotating shaft 23 and convey the recording sheet 3 using the conveying holes 22 formed at predetermined intervals at both ends in the width direction of the recording sheet 3.

An electromagnetic clutch 24 as a locking means is attached to one end of the rotation shaft 13 of the platen roller 2, and the electromagnetic clutch 24 is not rotated by the solenoid in which the rotation shaft 13 is applied. The mechanical lock of the rotating shaft 13 is prevented by rotation of the rotating shaft 13, and the mechanical lock of the rotating shaft 13 is released in the state where the rotating shaft 13 is energized.

Fig. 4 is a schematic circuit block diagram of the impact printer shown in Fig. 1, wherein the drive source 7 for conveying paper is controlled by a motor control signal from the MPU (Micro Processing Unit) 31 for controlling the sheet conveying motor, The drive source 15 is controlled by the motor control signal from the platen motor control MPU 32. The electromagnetic clutch 24 is controlled by the excitation control signal from the MPU 31 for controlling the paper conveying motor. The sheet conveying motor control MPU 31 and the platen motor control MPU 32 are controlled by the upper MPU 33, and the upper MPU 33 has an operator panel 34 having a key switch group operated by a user. The operation signal from) is input. The encoder signal is input from the sheet conveyance drive source 7 to the sheet conveying motor control MPU 31, and the encoder signal is input from the platen drive source 15 into the platen motor control MPU 32. Although not shown, the paper transfer motor control MPU 31 and the platen motor control MPU 32 include a ROM (Read Only Memory), a RAM (Random Access Memory) and a timer circuit. Connected.

Next, an outline of the operation will be described. During recording, the head pin of the recording head 1 is selectively projected and driven in accordance with the image data, and the tip of the head pin contacts the recording surface of the recording sheet 3 via the ink ribbon 4. As a result, the ink of the ink ribbon 4 is transferred to the recording surface of the recording sheet 3 in the form of dots, and an image corresponding to the image data is recorded. At this time, since the movement of the recording paper 3 in the paper thickness direction is restricted by the platen roller 2, the recording paper 3 is not pushed out by the impact of the head pin. This operation is repeated with the movement along the support rod 11 of the linear shuttle 12, and an image of one band is recorded on the recording surface of the recording sheet 3.

When one band of images is recorded by one advance or return of the linear shuttle 12, the paper conveying operation is commanded from the upper MPU 33 to the paper conveying motor control MPU 31, whereby the sheet conveying motor control is performed. The MPU 31 outputs a motor control signal to the drive source 7 for conveying paper. As a result, the output shaft of the drive source 7 for conveying paper rotates, and the rotational force is transmitted to the rotary shafts 21 and 23 via the pulley 7a and the endless belt 8, so that the upper tractor 5 and the lower tractor 6 As a result of the rotation, the recording sheet 3 is conveyed in the direction of the arrow in FIG. The conveyance amount at this time is determined by the distance between the area already recorded and the area to be recorded next, and the drive source 7 for conveying paper is driven by the number of steps corresponding to the conveyance amount. That is, the recording paper 3 is conveyed by the recording width in the sub-scanning direction by the recording head 1 in the region where images such as letters and graphics to be recorded are continued in the conveying direction of the recording paper 3, but should be recorded. The recording sheet 3 is conveyed by a distance longer than the recording width in the sub-scanning direction by the recording head 1 in a blank region or page boundary where no image exists.

At this time, the electromagnetic clutch 24 is controlled by the MPU 31 for controlling the sheet conveying motor, and the lock of the rotary shaft 13 by the electromagnetic clutch 24 is released while the sheet conveying drive source 7 is in operation. The roller 2 will be in a rotatable state. The platen roller 2 is controlled by the platen motor control MPU 32, and may or may not rotate depending on the required conveyance amount of the recording paper 3, and even when rotated, the platen driving source Although the operation stop point of the (15) is different from the operation stop point of the drive source 7 for conveying paper, a detailed description of the behavior of the platen roller 2 and the platen drive source 15 will be described later.

In this way, the recording by the recording head 1 and the conveyance of the sheet by the sheet conveyance drive source 7 are repeated every time the linear shuttle 12 advances and returns, and the image is recorded on the recording sheet 3.

FIG. 5 is a flowchart for explaining the control processing procedure of the platen drive source 15 by the platen motor control MPU 32 shown in FIG. 4, and the behavior of the platen roller 2 will be described with reference to this flowchart. .

First, the platen motor control MPU 32 determines whether or not a sheet conveying operation command is input from the upper MPU 33 (S1). That is, since the sheet conveying operation instruction from the upper MPU 33 is supplied to both of the sheet conveying motor control MPU 31 and the platen motor controlling MPU 32 at the same time, it is examined whether or not the sheet conveying operation instruction has been input. do.

When the sheet conveying operation command is input from the upper MPU 33 (S1: YES), the platen motor control MPU 32 determines whether the number of driving steps of the sheet conveying drive source 7 is equal to or greater than the predetermined number of steps ( S2). That is, since the data regarding the required conveyance amount of the recording sheet 3 is also input from the upper MPU 33 together with the sheet conveyance operation instruction, it is checked whether the required conveyance amount is greater than or equal to a predetermined value.

If the driving step number of the sheet conveying drive source 7 is equal to or greater than the predetermined step number (S2: YES), the platen motor control MPU 32 calculates the driving step number that should drive the platen driving source 15 (S3). . That is, since the platen roller 2 is heavy and the inertia force is stopped, the platen roller 2 continues to rotate by the inertia force even when the operation of the platen drive source 15 is stopped. When the stop point coincides with the stop point of operation of the drive source for conveying paper 7, even when recording is started by the recording head 1, the rotation of the platen roller 2 does not stop, resulting in deterioration of printing quality. The number of drive steps of the platen drive source 15 is calculated so that the operation stop time of the platen drive source 15 is set before the operation stop time of the paper conveyance drive source 7.

At this time, the platen operation time from the operation stop time of the platen drive source 15 to the operation stop time of the paper transfer drive source 7 is proportional to the conveyance amount of the recording paper 3 by the paper transfer drive source 7. The drive step number of the turning drive source 15 is calculated. That is, when the conveyance amount of the recording paper 3 is large, the rotation time of the platen roller 2 is long, and further, as described later, the rotation speed is increased, so that a large amount of time is required to recover the quiet state as a result of the increase of the accumulated energy. The time from the operation stop point of the platen drive source 15 to the operation stop point of the paper conveyance drive source 7 is lengthened.

Then, the platen motor control MPU 32 calculates the drive speed of the platen drive source 15 (S4). That is, when the conveyance amount of the recording paper 3 is large, when the difference between the circumferential speed of the upper tractor 5 and the lower tractor 6 and the circumferential speed of the platen roller 2 is large, the recording paper 3 is liable to be damaged. The conveyance speed of the recording paper 3 by the platen roller 2 is less than or equal to the conveyance speed of the recording paper 3 by the upper tractor 5 and the lower tractor 6, and the required conveyance of the recording paper 3. The driving speed of the platen drive source 15 is calculated to be proportional to the amount.

Then, the platen motor control MPU 32 starts driving the platen drive source 15 (S5). That is, supply of drive pulses to the platen drive source 15 is started. Thereby, the output shaft 16 of the platen drive source 15 rotates, the rotational force is transmitted to the rotating shaft 13 via the pulley 17, the endless belt 18, and the pulley 14, and the platen roller 2 ) Rotates.

FIG. 6 is an explanatory view for explaining the relationship between the rotational operation of the output shaft of the drive source 7 for conveying paper and the rotational operation of the output shaft 16 of the platen drive source 15. Here, the output shaft of the drive source 7 for conveying paper is shown. When the rotational speed of the output shaft 16 and the rotational speed of the output shaft 16 of the platen drive source 15 are the same, the circumferential speed of the upper tractor 5 and the lower tractor 6 and the circumferential speed of the platen roller 2 become equal. have. In Fig. 6, the vertical axis represents the rotational speed and the horizontal axis represents the number of drive steps. The rotation operation of the output shaft 16 of the platen drive source 15 is indicated by a solid line, and the rotation operation of the output shaft of the drive source 7 for conveying paper is shown. It is shown by the dashed-dotted line. As is also apparent from Fig. 6, the driving stop point of the output shaft 16 of the platen drive source 15 is earlier than the drive stop point of the output shaft of the paper conveyance drive source 7 and the output shaft of the platen drive source 15 The rotation speed of 16 is slower than the rotation speed of the output shaft of the drive source 7 for conveying paper. This is because the platen motor control MPU 32 has driven the platen drive source 15 based on the calculation results in steps S3 and S4. Thus, by controlling the platen roller 2, It aims at both preventing damage and preventing deterioration of printing quality.

Next, the platen motor control MPU 32 determines whether or not the drive of the platen drive source 15 is finished (S6). That is, it is checked whether or not the platen drive source 15 has been driven by the number of steps calculated in step S3.

When the driving of the platen drive source 15 is finished (S6: YES), this process ends. Even when the drive of the platen drive source 15 is finished, the platen roller 2 continues to rotate by the inertia force. At this point, since the drive source 7 for conveying the paper is driven, the recording paper 3 is being conveyed. Since the recording by the recording head 1 is not performed, there is no deterioration in printing quality even when the platen roller 2 rotates. Then, when the driving of the sheet conveyance drive source 7 is finished, the platen roller 2 is in a quiet state. That is, the preceding deceleration amount shown in Fig. 6 is set by predicting the time required for restoring the quiet state of the platen roller 2 from the experience value or the like.

In step S6, if drive of the platen drive source 15 is not complete | finished (S6: No), it returns to step S6 and waits for the drive of the platen drive source 15 to complete | finished.

In step S2, this process is complete | finished if the number of the drive steps of the drive source 7 for conveyance of paper is not more than predetermined step number (S2: No). That is, since the number of drive steps of the drive source for conveying paper 7 is not more than the predetermined number of steps, the required amount of conveyance of the recording paper 3 is less than or equal to the predetermined amount, so that the recording sheet 3 is not rotated even if the platen roller 2 is not rotated. Is not damaged, and when the platen roller 2 is rotated, the quiet state recovery time of the platen roller 2 cannot be secured, and the platen roller 2 is stopped even after the stop of the drive source 7 for conveying the paper. Since the rotation by the inertia force continues and the printing quality deteriorates, the platen roller 2 is not rotated.

In step S1, if the paper conveying operation command is not input from the upper MPU 33 (S1: No), the process returns to step S1 and waits for the paper conveying operation command to be input from the upper MPU 33.

The above operation is a mode in which the rotation of the platen roller 2 is automatically controlled, and the user manually controls the rotation of the platen roller 2 by performing a predetermined operation with the key switch group of the operator panel 34. Can be switched to That is, the user may prevent the platen drive source 15 from being operated during the operation of the drive source 7 for conveying paper by performing a predetermined operation by the key switch group of the operator panel 34, or the drive source for conveyance of paper ( The drive source 15 for the platen may always be operated during the operation of 7).

Moreover, in the said embodiment, although it was comprised so that the preceding deceleration amount and drive speed of the platen drive source 15 may be determined according to the conveyance amount of the recording sheet 3, the preceding deceleration amount and drive speed of the platen drive source 15 are made You may comprise so that it may determine according to the paper thickness of the recording paper 3. As shown in FIG. The control processing procedure of the platen drive source 15 by the platen motor control MPU 32 at this time will be described with reference to the flowchart shown in FIG.

First, the platen motor control MPU 32 determines whether or not a sheet conveying operation command is input from the upper MPU 33 (S11). That is, since the sheet conveying operation instruction from the sheet conveying motor control MPU 31 is simultaneously supplied to both of the sheet conveying motor control MPU 31 and the platen motor controlling MPU 32, it is determined whether the sheet conveying operation instruction has been input. Investigate whether or not.

When the sheet conveyance operation command is input from the upper MPU 33 (S11: Yes), the platen motor control MPU 32 determines whether or not the sheet thickness of the recording sheet 3 is greater than or equal to the predetermined thickness (S12). That is, since the data on the sheet thickness of the recording sheet 3 are also input from the upper MPU 33 together with the sheet conveying operation command, it is checked whether the sheet thickness is equal to or larger than a predetermined value. The term paper thickness here means the dimension of the thickest part when the thickness of the recording paper 3 is uneven, for example, when another sheet is attached to a part of each page of the recording paper 3. to be.

If the sheet thickness of the recording sheet 3 is equal to or greater than the predetermined thickness (S12: YES), the platen motor control MPU 32 calculates the number of drive steps that should drive the platen drive source 15 (S13). That is, since the platen roller 2 is heavy and the inertia force is large, the platen roller 2 continues to rotate by the inertia force even if the operation of the platen drive source 15 is stopped, and thus the platen drive source 15 When the stop point of operation coincides with the stop point of operation of the drive source 7 for conveying paper, even if recording is started by the recording head 1, the rotation of the platen roller 2 does not stop, resulting in deterioration of printing quality. Therefore, the number of drive steps of the platen drive source 15 is calculated so that the operation stop time of the platen drive source 15 is set before the operation stop time of the paper conveyance drive source 7.

At this time, the number of drive steps of the platen drive source 15 is such that the time from the operation stop point of the platen drive source 15 to the operation stop point of the paper conveyance drive source 7 is inversely proportional to the paper thickness of the recording sheet 3. Is calculated. That is, when the paper thickness of the recording paper 3 is thick, the recording paper 3 is liable to be damaged if the time for stopping the platen roller 2 is long during conveyance, so that the operation time of the platen drive source 15 is stopped. To shorten the operation stop point of the sheet conveyance drive source 7.

Then, the platen motor control MPU 32 calculates the drive speed of the platen drive source 15 (S14). That is, when the paper thickness of the recording paper 3 is thick, if the difference between the circumferential speed of the upper tractor 5 and the lower tractor 6 and the circumferential speed of the platen roller 2 is large, the recording paper 3 is liable to be damaged. , The conveying speed of the recording paper 3 by the platen roller 2 is less than or equal to the conveying speed of the recording paper 3 by the upper tractor 5 and the lower tractor 6, and the paper of the recording paper 3. The driving speed of the platen drive source 15 is calculated to be proportional to the thickness.

Then, the platen motor control MPU 32 starts driving the platen drive source 15 (S15). That is, supply of drive pulses to the platen drive source 15 is started. Thereby, the output shaft 16 of the platen drive source 15 rotates, the rotational force is transmitted to the rotating shaft 13 via the pulley 17, the endless belt 18, and the pulley 14, and the platen roller 2 ) Rotates.

Next, the platen motor control MPU 32 determines whether or not the drive of the platen drive source 15 is finished (S16). That is, it is checked whether or not the platen drive source 15 has been driven by the number of steps calculated in step S13.

When the driving of the platen drive source 15 is finished (S16: YES), this process ends. Even when the drive of the platen drive source 15 is finished, the platen roller 2 continues to rotate by the inertia force. At this point, since the drive source 7 for conveying the paper is driven, the recording paper 3 is being conveyed. Since the recording by the recording head 1 is not performed, there is no deterioration in printing quality even when the platen roller 2 rotates. Then, when the driving of the sheet conveyance drive source 7 is finished, the platen roller 2 is in a quiet state.

In step S16, if the drive of the platen drive source 15 is not complete | finished (S16: No), it returns to step S16 and waits for the drive of the platen drive source 15 to complete | finished.

In step S12, if the paper thickness of the recording sheet 3 is not more than the predetermined thickness (S12: NO), this process is terminated. That is, if the paper thickness of the recording paper 3 is thinner than the predetermined thickness, the recording paper 3 is not damaged even if the platen roller 2 is not rotated, so that the platen roller 2 is not rotated.

In step S11, if the paper conveying operation command is not input from the upper MPU 33 (S11: No), the process returns to step S11 and waits for the paper conveying operation command to be input from the upper MPU 33.

In the above embodiment, the platen drive source 15 during the operation of the paper conveyance drive source 7 only when the required conveyance amount of the recording paper 3 is equal to or greater than the predetermined amount or the paper thickness of the recording paper 3 is equal to or greater than the predetermined thickness. And the preceding deceleration amount and the driving speed of the platen drive source 15 were varied according to the required conveyance amount or paper thickness of the recording sheet 3, and the required conveyance amount of the recording sheet 3 was greater than or equal to a predetermined amount. Or control of operating the platen drive source 15 during operation of the paper conveyance drive source 7 only when the paper thickness of the recording paper 3 is greater than or equal to a predetermined thickness, and according to the required conveyance amount or paper thickness of the recording paper 3. Only one of the preceding deceleration amount and the control for varying the drive speed of the platen drive source 15 may be configured.

Moreover, you may comprise so that only one of a preceding deceleration amount and the drive speed of the platen drive source 15 may vary according to the required conveyance amount or paper thickness of the recording paper 3.

Moreover, in the said embodiment, although the electromagnetic clutch 24 was provided and it was comprised so that rotation of the platen roller 2 may be prevented when the drive source 7 for paper conveyance is not operating, the electromagnetic clutch 24 was platen. It may control by the motor control MPU 32, and may be comprised so that the rotation of the platen roller 2 may be prevented by the electromagnetic clutch 24 when the platen drive source 15 is not operating. And the electromagnetic clutch 24 does not need to be provided.

Moreover, in the said embodiment, although it comprised so that switching to the manual control mode by the operator panel 34, you may comprise so that switching to a manual control mode may be impossible.

As described above, according to the present invention, the platen roller is switched according to the required conveyance amount of the recording paper and the paper thickness of the recording paper, or the platen driving source is operated before the operation stop time of the paper conveying drive source. By stopping the gap between the recording head and the platen roller, damage to the recording paper can be prevented, and deterioration of the print quality due to the delay of the quiet state recovery of the platen roller due to the inertial force can be prevented. .

Claims (8)

An image recording apparatus comprising a recording head, a platen roller, and a conveying means for intermittently conveying a recording sheet in a predetermined direction in a predetermined direction, wherein A drive source for conveying paper, which drives the conveying means; A drive source for a platen for rotationally driving the platen roller; When the required conveyance amount of the recording paper is a predetermined amount or more, or when the paper thickness of the recording paper is a predetermined thickness or more, the platen driving source is operated during operation of the paper conveyance driving source, and the required conveyance amount of the recording paper is less than a predetermined amount; Or platen drive source control means for stopping the platen drive source during operation of the paper conveyance drive source when the paper thickness of the recording paper is less than a predetermined thickness. The image recording apparatus according to claim 1, wherein the platen drive source control means stops the operation of the platen drive source before the stop time of the paper conveyance drive source when the platen drive source is operated. An image recording apparatus comprising a recording head, a platen roller, and a conveying means for intermittently conveying a recording sheet in a predetermined direction in a predetermined direction, wherein A drive source for conveying paper, which drives the conveying means; A drive source for a platen for rotationally driving the platen roller; And a platen drive source control means for starting the operation of the platen drive source in accordance with the start of operation of the paper conveyance drive source and stopping the operation of the platen drive source before the operation stop time of the paper conveyance drive source. An image recording device. 4. The platen drive source control means according to claim 2 or 3, wherein the time from the operation stop point of the platen drive source to the operation stop point of the paper transfer drive source is proportional to the required conveyance amount of the recording sheet, Or the drive source for the platen so as to be inversely proportional to the sheet thickness of the recording sheet. The said drive source control means for platens is a conveyance speed of the said recording paper by the said platen roller, The conveyance speed of the said recording paper by the said conveying means is less than And the drive source for the platen is controlled so as to be proportional to the conveyance amount or the paper thickness of the recording sheet. The image recording apparatus according to any one of claims 1 to 3, comprising lock means for preventing rotation of the platen roller when the drive source for conveying the paper is not in operation. 4. An image recording apparatus according to any one of claims 1 to 3, comprising lock means for preventing rotation of the platen roller when the drive source for the platen is not in operation. The method according to any one of claims 1 to 3, wherein the control operation by the platen drive source control means is prohibited based on the instruction operation by the user, and the operation of the platen drive source is controlled in accordance with the instruction operation. An image recording apparatus comprising a forced control means.

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