JPH10202852A - Sheet-feed device of ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sheet-feed device generating no open face in a character or image caused by excessive feed or feed delay or forming no double image. SOLUTION: Feed members 101, 103 moving a sheet P in a definite direction, the member 105 to be detected moved in the same direction as the moving direction of the sheet P moved by the feed members 101, 103 at the same speed as the moving speed of the sheet, a recording head 108 forming an image on the sheet while moved in the direction right-angled to the moving direction of the sheet P, the detection member 107 detecting the member 105 to be detected, the drive means M, M1 moving the feed members 101, 103 and the member 105 to be detected and the control means C controlling the drive means M, M1 are provided and, by detecting the member 105 to be detected moved at the same speed as the moving speed of the sheet, the member 105 to be detected and the sheet P are stopped at a predetermined image forming position to form an image on the sheet by the recording head 108.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer for forming an image by ejecting ink droplets from a recording head onto a sheet moving in a certain direction, and more particularly, to forming an image from the recording head when the sheet is formed. The present invention relates to an ink jet printer that accurately stops at a correct image forming position to obtain a good image.

[0002]

2. Description of the Related Art FIG. 6A is a perspective view showing a conventional ink jet printer.

In general, an ink jet printer has a configuration in which a recording head is provided on a carriage 2 and ink reservoirs 3, 3 for supplying the carriage 2 with ink to the recording head.
A is provided, and the carriage 2 is connected to the control board 9 by a flexible cable 5.

The carriage 2 is reciprocated by a carriage driving mechanism 6 in a main scanning direction indicated by an arrow X in the drawing.
The carriage driving mechanism 6 includes a mechanism including a motor 6a, a pulley 6b, a timing belt 6c, and a guide rail 6d.
And is reciprocated in the direction of arrow X by the motor 6a via the timing belt 6c.

Reference numeral 8 denotes a paper transport mechanism which transports the sheet P in the sub-scanning direction indicated by an arrow Y in the figure, and includes a transport motor 8a and a pair of transport rollers 8b and 8c. Transport roller 8b
And the transport roller 8c are driven by the transport motor 8a,
An interlocking mechanism (not shown) is provided so that the conveying roller 8c rotates at a very high peripheral speed. A sheet (hereinafter, referred to as a recording sheet P) is sent out from a sheet feeding mechanism (not shown), and is then sandwiched by conveyance rollers 8b. The sheet feeding guide (not shown) corrects the direction of conveyance in the sub-scanning direction. Then, the sheet is conveyed while being nipped by the conveying roller 8c. Since the peripheral speed of the transport roller 8c is extremely slightly faster than that of the transport roller 8b, the recording paper P passes through the recording section without causing slack. The speed at which the recording paper P moves in the sub-scanning direction is set to a constant speed.

In this manner, while moving the recording paper P at a constant speed in the sub-scanning direction, the carriage 2 is moved at a constant speed in the main scanning direction, and the ink ejected from the recording head is adhered to one side of the recording paper P. The image is recorded in a predetermined range.

[0007]

As described above, conventionally, the carriage 2 provided with the recording head is reciprocated in the main scanning direction indicated by the arrow X in FIG. Printing and image formation are performed on the recording paper P by transporting the recording paper P in the sub-scanning direction indicated by the arrow Y in the figure by the transport mechanism 8.

In this case, characters or images are formed in lines by a plurality of minute ejection ports formed in a line on the recording head.
Next, the recording paper P is transported in the sub-scanning direction by the width of a plurality of ejection ports, and a character or an image for the next line is formed. That is, after forming a line, a character, or an image of one line by a plurality of ejection port widths, an accurate character or image is formed unless the recording paper P is accurately conveyed by the ejection port width. Can not. Therefore, 1 / multiple of the width of multiple jet ports
There is also a method of feeding the recording paper P by 2 or 1/4 in the sub-scanning direction and making the movement unevenness of the recording paper P inconspicuous.
In this case, particularly when an image is formed, the sharpness of the image is improved, but the recording speed is reduced.

The image is formed on the recording paper by using the recording head by the above-mentioned method. In the carriage provided with the recording head as described above, the predetermined position can be accurately determined by the driving timing belt 6c and the guide rail 6d. Are provided so as to reciprocate in the main scanning direction, and sequentially form characters or images. On the other hand, the recording paper P conveyed in the sub-scanning direction is provided so as to be moved by a rotating conveyance roller or the like. In order to drive and rotate the transport roller, the drive roller rotates via a reduction gear from a drive gear provided in a motor of a drive source, and transmits a driving force to the transport roller.

In an ink jet printer, a normal character or image can be obtained for the first time by moving a recording head in a main scanning direction at a constant speed and feeding a recording paper P at a constant width in a sub scanning direction. However, even if the rotation unevenness of the drive motor and the accuracy of the tooth tips of the drive gear and the reduction gear are processed with considerably high precision, backlash is formed to rotate the gear smoothly, and at the time of rotation, Since rotation unevenness due to backlash is inevitable, the rotation unevenness appears as movement unevenness of the recording paper P. In addition, since the surface of the transport roller is coated with a thin resin or rubber or the like to prevent slippage between the transport roller and the recording paper P, the roundness varies, and the surface has some unevenness or distortion. The recording paper P is moved in a state where is formed. Therefore,
The unevenness of the transport roller or the movement difference due to the distortion results in the movement unevenness of the recording paper P.

In the recording head, the ejection port having a small diameter is
A plurality of lines are provided in a line state in the vertical direction with respect to the moving direction of the recording head, and ink droplets are ejected from each ejection port in response to image recording output.

As shown in FIG. 6B, characters or images are formed by moving in the main scanning direction X at a constant speed while ejecting ink droplets from an ejection port having a small diameter. As described above, when the recording paper P moving in the sub-scanning direction Y has a movement unevenness, and the movement of the recording paper P exceeds a predetermined distance, a portion where characters or images are originally formed by the recording head passes. In addition, the image P1 due to the ink droplets is not accurately formed, and a white spot P2 (a part of a character or an image is not formed and is cut off) occurs. In this way, the image P1 is not continuously formed. Conversely, if the recording paper P is not moved a predetermined distance, for example, a part of an image formed by ink droplets is overlapped (a part of a character or an image is formed at a predetermined density or more). Therefore, if the movement unevenness occurs on the recording paper P, a blank area or an ugly image due to the overlapping image is generated.

The present invention has been made to solve the above problems. That is, when a character or an image is formed on a recording paper by ink droplets ejected from the recording head by moving the recording head, the recording paper is accurately moved at an interval at which a predetermined character or image can be formed, and the recording paper has a good quality. It is an object of the present invention to provide an ink jet printer for forming characters or images.

[0014]

According to the first aspect of the present invention, a sheet moving in a certain direction is provided.
In an ink jet printer that ejects ink droplets from a recording head to form an image, a conveying member that moves the sheet in a certain direction, and a moving direction of the sheet that is moved by the conveying member, and A detection member that moves at the same speed as the moving speed, the recording head that forms an image on a sheet while moving in a direction perpendicular to the moving direction of the sheet, a detection member that detects the detection member, and the conveyance A drive unit for moving a member and the detected member, and a control unit for controlling the drive unit, wherein the detected member detects the detected member moving at the same speed as the moving speed of the sheet. And stopping the sheet to be detected and the sheet at a predetermined image forming position, and forming an image on the sheet by the recording head.

3. The sheet detecting device according to claim 2, wherein the detected member is provided on a conveying member which moves the sheet in a predetermined direction, and the detected mark provided on the detected member is detected by the detecting member to detect the sheet. Is stopped at a predetermined image forming position, and an image is formed on a sheet by the recording head.

The detected member provided on the conveying member may be formed by an endless belt, suspended on the rotating conveying member in parallel with a sheet conveying direction, and the detection member may be rotated by rotation of the conveying member. Being provided so as to pass through the detecting member.

In an ink jet printer for forming an image by ejecting ink droplets from a recording head to a sheet moving in a certain direction, a cylindrical conveying member for moving the sheet in a certain direction. A driving unit for driving the conveying member; a recording head for forming an image on a sheet while moving in a direction perpendicular to a moving direction of the sheet; and a rotating circumferential position of the conveying member. A detecting member provided with a plurality of detected portions provided corresponding to positions, a detecting device for detecting the plurality of detected portions, and a control device for controlling the driving device; After the plurality of detected parts are detected by the detecting means by the rotation of the member, the divided rotation circumferential distances are sequentially stored in the control means until the next detected part is detected by the detecting means. Depending on the circumference , Controls the conveying member by said control means, said by the conveying member is stopped the sheet at a predetermined image forming position, to perform an image formation on the sheet in the recording head.

According to a fifth aspect of the present invention, the detected member provided with a plurality of detected portions provided respectively corresponding to the rotation circumferential position of the transport member is provided coaxially with the transport member,
This is achieved by rotating the detected member and the conveying member in the same direction, and detecting the detected portion with the detecting member.

[0019]

FIG. 1 is a perspective view showing the overall configuration of an ink jet printer 100 according to the present invention.

A transport roller 101, which is a transport member for recording paper P on which characters or images are recorded, and a transport roller 103 are connected to the inkjet printer 100 via shafts 102 and 104.
Is provided rotatably. Axis 1 of transport roller 101
A drive motor M, which is a driving means, is connected to 02 so as to rotate the transport roller 101 to feed and transport the recording paper P. When the recording paper P is fed and transported by the transport roller 101, for example, the recording paper P fed from the paper feed cassette is wound around a part of the transport roller 101, and the recording paper P is fed.
To move. That is, the recording paper is fed in the sub-scanning direction.

A recording head 108 guides the guide member 10 so as to be movable in a direction perpendicular to the paper feeding direction of the recording paper P.
9. The recording head 108 is fixed to a part of the drive wire 111 suspended on the pulleys 112 and 113 so that the recording head 108 can reciprocate by the width of the recording paper P, and the pulley 113 is connected to the motor M1 to drive the motor M1. The recording head 108 is reciprocated by the guide member 109 with the width of the recording paper P via the driving wire 111.

The structure of the recording head 108 is such that a large number of ejection ports from which ink droplets are ejected are provided on one side of the recording head 108, and the ink droplets are ejected from the ejection port by an image signal or a printing signal. Or form a character.

Further, between the transport roller 101 and the transport roller 103 disposed in the horizontal direction, a belt-shaped member formed of a PET sheet is formed in the same direction as the recording paper P is fed and transported. The detection member 105 is suspended. The detected member 105 is provided so as to move at the same speed as the moving speed of the recording paper P and in parallel in the same direction by the rotation of the transport roller 101.

Further, a detection member 107 is provided at a part where the detection member 105 passes, and a detection mark 106 detected by the detection member 107 is provided on the detection member 105 in the longitudinal direction of the detection member 105. Are provided along.

C is a control means, which inputs a detection signal of detecting the detection target mark 106 by the detection member 107 through the input / output means C1, and drives the drive motors M, M
1 is driven and stopped.

By the drive motor M, the transport rollers 10
1 is rotated in the direction of the arrow, the recording paper P is conveyed in the sub-scanning direction, and the recording head 108 forms a character or image P1 while moving in the main scanning direction.
The recording paper guide plate 114 faces the recording head 108 so that the recording paper P at the position where recording is performed is stably conveyed.
Is provided, and the recording paper P is guided by the recording paper guide plate 114, so that the curvature of the recording paper P is prevented. Further, the recording paper P is discharged and conveyed outside by a pair of conveying rollers 110.

As shown in FIG. 1, the feeding of the recording paper P is started, and the conveying roller 101 is driven by a driving motor M via a shaft 102.
The recording paper P is wound around the transport roller 101 and transported in the direction of the recording head 108 by rotating in the direction of the arrow. At the same time, the detection member 105 arranged side by side
01, in parallel with the recording paper P in the same direction and at the same speed, the detection member 107
The five detection target marks 106 are sequentially read. In order to form a character or an image on the recording paper P, the recording head 108 reaches an accurate position with respect to the recording head 108 and stops.

Next, the pulley 113 is rotated by the drive motor M1, and the recording head 108 is moved by the guide member 109 in the main scanning direction via the drive wire 111, and the output signal from the character or image output unit is output. To form characters or images on the recording paper P while ejecting ink droplets.

Next, the control means C starts the rotation of the transport roller 101 by the drive motor M via the input / output means C1 so that the detection member 107 sequentially reads the detection marks 106 of the detection member 105. It is configured.

FIG. 2 is a diagram showing the state of movement of the recording paper P when the detection member 107 reads the detection mark 106 of the detection member 105.

The detection target member 105 formed in a belt shape and suspended on the conveyance roller 101 has detection target marks 106 marked at intervals of a width L [70.55 μm (360 DPI)] in all the moving directions. And is provided so as to pass through the position of the detection member 107.

On the other hand, the recording paper P is also moved by the transport roller 101 in the same direction as the moving direction of the detecting member 107 and in parallel at the same speed. The detected marks 106 are sequentially read, and the number of passages of the detected marks 106 is counted by the control means C via the input / output means C1. When the recording head 108 reaches a position where a continuous image is to be formed by counting the detection mark 106, the driving motor M is stopped by the control means C via the input / output means C1, and the detection member 105 is moved together with the transport roller 101. And the recording paper P also stops.
At this time, the recording paper also has a fixed width L of the detection target mark 106.
The stop position is a position where an accurate character or image is formed on the recording paper P.

Next, the drive motor M1 is driven by the control means C via the input / output means C1 to rotate the pulley 113, and the recording head 108 is moved in the main scanning direction via the drive wire 111.
Is moved while being guided by the guide member 109, and a good character or image continuous with the previous character or image is formed on the recording paper P while ejecting ink droplets by the output signal from the character or image output unit.

The detection target marks 106 formed at the intervals of the width L are easy and accurate to detect, and can be stopped at an accurate position. Therefore, the recording paper P can also be stopped at an accurate position.

FIGS. 3A and 3B show the detection member 10.
7, the detection mark 106 of the detection member 105
FIG. 4 is a configuration diagram showing an embodiment for detecting a state.

FIG. 3A shows a state in which a light emitting unit 107A and a light receiving element 107B are provided at a fixed angle in a detecting member 107, and the reflected light of the light emitting unit 107A when the detection mark 106 of the detected member 105 passes therethrough. Is reflected only by the detection mark 106 and received by the light receiving element 107B, or the detection mark 106 is made black so that the reflected light is absorbed and is not reflected. Mark 1
06 are sequentially detected.

FIG. 3B shows a light emitting unit 107A disposed above the detection member 105 and a light receiving element 1 disposed below.
7B shows a detection member 107 provided with 07B. Detected member 10
When the detection mark 106 of No. 5 passes between the light emitting unit 107A and the light receiving element 107B, the light of the light emitting unit 107A is not received by the light receiving element 107B at the position of the detection mark 106, and the position other than the detection mark 106 Then, the light emitting unit 10
By causing the light 7A to be received by the light receiving element 107B, the detection means 107 sequentially detects the detection target marks 106.

The detection member 105 can be formed by printing the detection mark 106 on a thin PET film. For example, the detection member 105 is exposed, developed, and fixed to form a black detection mark 106. , Belt-shaped detection member 1
05. Alternatively, the detection target member 105 may be formed by processing a belt-like film into black and forming a slit only in the detection mark 106.

In the above embodiment, the detection member 115 having a plurality of detection slits 116 is suspended on the conveyance roller 101 for conveying the recording paper P, and the detection mark 106 of the detection member 115 is detected by the detection member 107. Means to stop the recording paper P accurately, for example,
01, a mark at a constant interval corresponding to the mark to be detected 106 is provided in the circumferential direction of a portion where the recording paper P is not conveyed, or a part of the side surface, and the mark is detected by the detecting member 107;
The control means C controls the drive motor M,
, The recording paper P may be stopped accurately.

The mark may be provided with black lines at regular intervals, or may be provided with white lines at regular intervals on a black surface.

FIG. 4 is a perspective view of the overall configuration showing another embodiment of the ink jet printer 100 of the present invention.

In this embodiment, the same parts as those in FIG. 1 will be described using the same reference numerals.

The ink jet printer 100 is rotatably provided via a shaft 102 of a conveying roller 101 which is a cylindrical conveying member for conveying the recording paper P. A transport roller 101 is provided on a shaft 102 of the transport roller 101.
A gear G1 is fixedly provided on the shaft 102 in order to rotate and feed the recording paper P, and a driving gear G provided on a driving motor M1 as a driving means for driving the gear G1.
With the gear G1. When the recording paper P is fed and transported by the transport roller 101, for example, the recording paper P fed from the paper feed cassette is brought into contact with a part of the transport roller 101 to move the recording paper P. That is, the recording paper is fed in the sub-scanning direction.

Further, the shaft 102 of the transport roller 101 has
A detection member 115 having a plurality of detection slits 116 formed in a circumferential direction is fixedly provided, and a conveying roller 101 is provided.
Rotate with. Further, a detection member 117 for detecting the detection slit 116 is provided to face the detection member 115.

A recording head 108 guides the guide member 10 so that it can move in a direction perpendicular to the paper feeding direction of the recording paper P.
9. The recording head 108 is fixed to a part of the drive wire 111 suspended on the pulleys 112 and 113 so that the recording head 108 can reciprocate with the width of the recording paper P, and the pulley 113 is connected to the drive motor M1 to drive the drive motor M1. , The recording head 108 is reciprocated by the width of the recording paper P via the driving wire 111.

The structure of the recording head 108 is such that a large number of ejection ports from which ink droplets are ejected are provided on one side of the recording head 108, and the ink droplets are ejected from the ejection port by an image signal or a printing signal. Or form a character.

C is a control means, which inputs a detection signal detected by the detection member 117 of the slit 116 to be detected via the input / output means C1, and controls the drive and stop of the drive motors M, M1.

The recording paper P is transported in the sub-scanning direction by the transport roller 101, and the recording head 108 forms a character or image P1 while moving in the main scanning direction. A recording paper guide plate 114 is provided to face the recording head 108 so that the recording paper P is stably conveyed.
4, the recording paper P is prevented from being curved. Further, the recording paper P is discharged and conveyed outside by a pair of conveying rollers 110.

FIG. 5 shows the slit 11 for detection of the rotating detection member 115 provided on the shaft 102 of the conveying roller 101.
6 and a front view showing a detection member 117.

First, when the recording paper P is transported by the transport roller 101, the following adjustments are made.

The rotation circumferential position of the transport roller 101 is divided into a, b, c, d, e, f, g, and h, and the entire circumference of the detected member 115 provided on the shaft 102 of the transport roller 101 is provided. , The detected slit 116 corresponding to the section a, b, c, d, e, f, g, h corresponding to the detected portion.
Are formed.

As an adjustment method for moving the recording paper P, the reduction ratio from the drive motor M2 to the transport roller 101 via the drive gear G and the gear G1 is set to an integral multiple, and the transport roller 10
1, so that the rotational positions of the drive gear G, the gear G1, and the drive motor M2 are the same. Before formal characters or images are recorded on the recording paper P by the recording head 108, provisional recording paper is transported by the transport rollers 101. At this time, the recording paper P is conveyed according to the rotation circumferential position of the conveying roller 101, and the character or image P1 is recorded while moving the recording head 108 in the main scanning direction.

Next, a, b, c, d, e, f, g, and g are divided by one rotation of the rotation circumferential distance of the transport roller 101.
In the image of the section h, white spots and overlapping states are confirmed. Therefore, for example, a large white spot occurs in a and a small white spot occurs in b. In c, it is assumed that an overlapping state of images has occurred. In this section, it can be seen that the recording paper P is not conveyed at a constant conveying distance because the backlash between the driving gear G and the gear G1 and the surface of the conveying roller 101 have minute unevenness or distortion.

A, b, and b are divided based on the above data.
In the sections c, d, e, f, g, and h, the transport distance of the recording paper P is adjusted to be a predetermined transport distance.

The drive motor M2 is suitably a servomotor whose rotation can be easily controlled.

Next, each of the sections a, b, and c is detected by the detection slit 116 of the detection target member 115 and the detection member 117, and a, b, c, and d are classified based on the data. ,
For the sections e, f, g, and h, the slit 11 to be detected
According to the measurement between 6, a is +10 μm, b is +2 μm, c
Indicates the rotation adjustment value of each section, such as -8 μm,
Input to the rotation control unit. Of course, the sections d, e, f, g, and h are also measured in the same manner as described above and input to the rotation control unit.
Thus, a, b, c, d, e, f, g,
By inputting the rotation adjustment value of each section of h, each section of the transport roller 101 causes the drive motor M2 to rotate at the adjusted peripheral speed according to the rotation adjustment value of the control means C,
Even if characters or images are recorded by moving the recording head 108 in the main scanning direction to convey the recording paper P, a good image is formed on the recording paper P without white spots or duplication. I can do it.

The sections a, b, c, d, e, f, g, and h of the detected member 115 are formed by the slits 116 to be detected. Alternatively, the detection may be performed by providing a reflection mark at a position corresponding to the above. Alternatively, the detection may be performed by providing a black mark on a white surface.

[0058]

As described above, according to the first aspect, in an ink jet printer which forms an image by ejecting ink droplets from a recording head to a sheet moving in a certain direction, the sheet is moved in a certain direction. A moving member, a detected member moving in the same direction as the moving direction of the sheet moved by the conveying member, and moving at the same speed as the moving speed of the sheet, and a direction perpendicular to the moving direction of the sheet. The recording head that forms an image on a sheet while moving, a detection member that detects the detected member, a driving unit that moves the transport member and the detected member, and a control unit that controls the driving unit. The detection member detects the detected member moving at the same speed as the moving speed of the sheet, so that the detected member and the sheet are stopped at a predetermined image forming position. By performing image formation on the sheet with the recording head, the detection member detects a member to be detected that moves in the same direction at the same moving speed as the recording sheet, and moves the sheet to a predetermined image forming position. By stopping accurately, a continuous good image can be obtained by the recording head.

According to a second aspect of the present invention, the detected member is provided on a conveying member which moves the sheet in a predetermined direction, and the detected mark provided on the detected member is detected by the detecting member to detect the detected sheet. Is stopped at a predetermined image forming position, and an image is formed on a sheet by the recording head, so that a detected mark is provided on the detected member, and the detected mark is detected by the detecting member. The detection of the detected member that moves in a certain direction together with the sheet by the member can be performed easily and accurately. Therefore, the sheet can be accurately stopped together with the detected member.

According to a third aspect of the present invention, the detected member provided on the conveying member is formed of an endless belt, and is suspended in parallel with a sheet conveying direction on the rotating roll-shaped conveying member. Since the detection member is provided on the conveyance member that conveys the sheet by being provided so as to pass through the detection member by rotation, the conveyance of the sheet and the movement of the detection member are completely synchronized, The sheet can be accurately stopped together with the detected member.

In an ink jet printer for forming an image by ejecting ink droplets from a recording head onto a sheet moving in a certain direction, a cylindrical conveying member for moving the sheet in a certain direction. A driving unit for driving the conveying member; a recording head for forming an image on a sheet while moving in a direction perpendicular to a moving direction of the sheet; and a rotating circumferential position of the conveying member. A detecting member provided with a plurality of detected portions provided corresponding to positions, a detecting device for detecting the plurality of detected portions, and a control device for controlling the driving device; After the plurality of detected parts are detected by the detecting means by the rotation of the member, the divided rotation circumferential distances are sequentially stored in the control means until the next detected part is detected by the detecting means. Depending on the circumference Controlling the conveying member by the control means, stopping the sheet at a predetermined image forming position by the conveying member, and forming an image on the sheet by the recording head, thereby rotating the conveying member for conveying the sheet. By dividing the peripheral position, the movement amount at each of the divided positions is input to the control means, the conveying member is controlled to stop the sheet at an accurate position, and a good image can be obtained.

According to a fifth aspect, the detected member provided with a plurality of detected portions provided respectively corresponding to the rotation circumferential position of the transport member is provided coaxially with the transport member,
The detected member and the conveying member rotate in the same direction, and the detected member is detected by the detecting member, so that the detected portion provided coaxially with the conveying member that conveys the sheet moves the rotation circumferential position separately. By controlling and inputting the amount and accurately controlling each section of the conveying member, the sheet can be stopped at a correct position and a good image can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of an inkjet printer according to the present invention.

FIG. 2 is a configuration diagram illustrating a detected member of the present invention and a moving state of a recording sheet P.

FIG. 3 is a configuration diagram showing a configuration of a detected member and a detection member of the present invention.

FIG. 4 is a perspective view showing the overall configuration of another embodiment of the ink jet printer of the present invention.

FIG. 5 is a front view showing a conveyance roller of the present invention and a slit for detection of a detected member.

FIG. 6 is an overall configuration diagram of a conventional inkjet printer and a perspective view and an explanatory diagram showing image formation.

[Explanation of symbols]

 Reference Signs List 1,100 Inkjet printer 2 Carriage 3, 3A Ink reservoir 5 Flexible cable 7 Encoder 9 Control board C Control means M, M1, M2 Drive motor 101, 103 Transport roller 105, 115 Detected member 107, 117 Detecting member 108 Recording head

Claims (5)

[Claims] 1. An ink jet printer which forms an image by ejecting ink droplets from a recording head onto a sheet to be moved in a certain direction, comprising: a conveying member for moving the sheet in a certain direction; A detected member that moves in the same direction as the moving direction of the sheet and at the same speed as the moving speed of the sheet; and the recording head that forms an image on the sheet while moving in a direction perpendicular to the moving direction of the sheet. A detecting member for detecting the detected member, a driving unit for moving the conveying member and the detected member, and a control unit for controlling the driving unit, the moving unit moving at the same speed as the moving speed of the sheet The detected member is detected by the detecting member to stop the detected member and the sheet at a predetermined image forming position, and the recording head forms an image on the sheet. Sheet conveying apparatus of an ink jet printer and performing. 2. The apparatus according to claim 1, wherein the detected member is provided on a conveying member that moves the sheet in a predetermined direction, and a detection mark provided on the detected member is detected by the detecting member to form the sheet into a predetermined image. 2. The sheet conveying apparatus according to claim 1, wherein the sheet is stopped at a position, and an image is formed on a sheet by the recording head. 3. The detection member provided on the conveyance member is formed by an endless belt, is suspended in parallel with a sheet conveyance direction on the rotating conveyance member, and passes through the detection member by rotation of the conveyance member. The sheet conveying device of an ink jet printer according to claim 1, wherein the sheet conveying device is provided as described above. 4. An ink-jet printer for forming an image by ejecting ink droplets from a recording head onto a sheet moving in a certain direction, comprising: a cylindrical conveying member for moving the sheet in a certain direction; And a recording head that forms an image on a sheet while moving in a direction perpendicular to the direction of movement of the sheet, and a rotating circumferential position of the transport member is divided, and corresponding to each divided position. A detection member provided with a plurality of detection units provided respectively, a detection unit for detecting the plurality of detection units, and a control unit for controlling the driving unit, the rotation of the conveyance member After the plurality of detected parts are detected by the detection means, the divided rotation circumferential distances are sequentially stored in the control means until the next detection part is detected by the detection means, and according to the rotation circumference distance, , The conveying member The controlled by the control means, wherein the conveying member is stopped the sheet at a predetermined image forming position, the sheet conveying apparatus of an ink jet printer, characterized in that an image is formed on the sheet by the recording head. 5. The detection member provided with a plurality of detection portions provided respectively corresponding to the rotation circumferential position of the conveyance member, the detection member is provided coaxially with the conveyance member, and the detection member and the conveyance member are provided. 5. The sheet conveying device of an ink jet printer according to claim 4, wherein the detecting member rotates in the same direction and detects the detected portion with a detecting member.