JP3815055B2 - Print medium conveying apparatus and printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a print medium conveyance device and a printer, and more particularly to a print medium conveyance device that conveys a print medium step by step by a predetermined distance and a printer including such a print medium conveyance device.
[0002]
[Prior art]
For example, in an inkjet printer or the like, an image or characters are printed (recorded) by ejecting a liquid, that is, an ink droplet, onto a print medium such as paper from a nozzle of a liquid ejection unit, that is, a print head. In the case of color printing, for example, the print head has ink heads for each of the four primary colors of cyan, magenta, yellow, and black, and various color images and the like can be obtained by combinations of ink dots blown from each ink head. expressing. The density of ink dots constituting an image or the like is about several tens to several thousand hundreds of dpi. The combination of ink dot colors and the pattern formed by them are specified by drawing data supplied from a control device (computer).
[0003]
FIG. 5 is a schematic configuration diagram of a conventional example of an inkjet printer. In the inkjet printer 1, recording heads 3 and 3 </ b> A are mounted on a carriage 2, and the recording heads 3 and 3 </ b> A are connected to a control board 9 by a flexible cable 5. The recording heads 3, 3A have a plurality of nozzles (not shown) on the side facing the recording paper P. The plurality of nozzles are arranged along the sub-scanning direction indicated by arrow Y in the figure.
[0004]
The carriage 2 is driven by a carriage drive mechanism 6 and reciprocates in the main scanning direction indicated by an arrow X in the figure. The carriage drive mechanism 6 includes a mechanism including a motor 6a, a pulley 6b, a timing belt 6c, and a guide rail 6d. The carriage 2 is fixed to the timing belt 6c, and is driven by the motor 6a via the timing belt 6c.
[0005]
A paper transport mechanism 8 intermittently transports the recording paper P in the sub-scanning direction indicated by the arrow Y. The intermittent transport distance corresponds to the width of the band-like area recorded by the recording heads 3 and 3A by one main scanning. The paper transport mechanism 8 is configured by a mechanism including a transport motor 8a and transport rollers 8b and 8c. The transport roller 8b and the transport roller 8c are driven by a transport motor 8a via an interlocking mechanism (not shown) so that the transport roller 8c rotates at a slightly faster peripheral speed than the transport roller 8b.
[0006]
The recording paper P is sent out from a paper feeding unit (not shown) and is sandwiched between transport rollers 8b. The transport direction is corrected by a paper feeding guide (not shown), and the paper P is sandwiched and transported between transport rollers 8c. Since the peripheral speed of the transport roller 8c is slightly faster than that of the transport roller 8b, the recording paper P is transported between the transport rollers 8b and 8c, that is, without causing slack in the recording space.
[0007]
The recording paper P is conveyed by the above-mentioned fixed distance in the sub-scanning direction every time the carriage 2 performs the main scanning once, and a character or an image as an adhesion trace of ink droplets discharged from the recording heads 3 and 3A on the surface thereof. Is formed.
[0008]
[Problems to be solved by the invention]
In the ink jet printer as described above, characters or images (hereinafter referred to as “images”) can be recorded correctly only after the recording paper P can be fed accurately at a constant distance in the sub-scanning direction. Therefore, unevenness occurs in the transport distance of the recording paper P in the sub-scanning direction. Further, when a reduction gear or the like is provided in the driving force transmission system, uneven rotation due to backlash of the gear system is unavoidable. Further, when the surface of the transport rollers 8b and 8c is coated with a rubber coating for increasing friction with the recording paper P, unevenness in the transport distance occurs due to variations in roundness, surface irregularities or distortions, and the like.
[0009]
When the conveyance distance of the recording paper P becomes larger than a predetermined distance due to unevenness in the conveyance distance, the original dot position for forming an image or the like is exceeded, and for example, as shown in FIG. If a missing P2 occurs (part of the image or the like is cut out) and the transport distance of the recording paper P becomes shorter than a predetermined distance, for example, part of the image due to ink droplets overlaps. As a result, the density of the image or the like is partially increased, and in any case, the quality of the image or the like recorded on the recording paper P is deteriorated.
[0010]
The present invention has been made to solve the above-described problems, and an object of the present invention is to realize a print medium conveying apparatus that accurately conveys a print medium and a printer including such a print medium conveying apparatus. .
[0011]
[Means for Solving the Problems]
(1) The invention of claim 1 for solving the problem comprises a conveying means for conveying a print medium by a rotating member rotating with a pulse motor as a driving source; Designed to generate encoder pulses at intervals longer than the moving distance of the rotating member on the print medium transport surface that rotates by generating an encoder pulse corresponding to the rotation of the rotating member and applying one pulse to the pulse motor. Encoder When , Transport of print media based on encoder pulse As well as controlling When the target transport amount includes a transport amount that is less than or equal to the minimum transport amount that can be controlled by this encoder pulse, the transport amount that is less than or equal to the minimum transport amount is transported based on the number of pulses applied to the pulse motor. Control And a control means for controlling the print medium.
[0012]
In the first aspect of the invention, the control means corrects the transport distance error of less than one unit of quantization by the number of input pulses of the pulse motor, and performs accurate print medium transport.
[0013]
(2) The invention of claim 2 for solving the problem is Encoder 2. The print medium transport apparatus according to claim 1, wherein a belt-shaped member that carries a repetitive pattern of binary signals and is transported simultaneously with the print medium by the transport means is used.
[0014]
In the invention of claim 2, Encoder However, the transport distance is quantized using a belt-like member that carries a repetitive pattern of binary signals and is transported simultaneously with the print medium.
(3) The invention of claim 3 for solving the problem is Encoder 2. The print medium conveying apparatus according to claim 1, wherein a disk-shaped member that carries a repetitive pattern of binary signals and rotates simultaneously with the rotating member is used.
[0015]
In the invention of claim 3, Encoder However, the transport distance is quantized using a disk-shaped member that carries a repetitive pattern of binary signals and rotates simultaneously with the rotating member for transporting the print medium.
[0016]
(4) A fourth aspect of the invention for solving the problem is a printer that performs printing with a print head on a print medium that is conveyed step by step by a fixed distance, and is a rotating member that rotates using a pulse motor as a drive source. Conveying means for conveying a print medium by Designed to generate encoder pulses at intervals longer than the moving distance of the rotating member on the print medium transport surface that rotates by generating an encoder pulse corresponding to the rotation of the rotating member and applying one pulse to the pulse motor. Encoder When , Transport of print media based on encoder pulse As well as controlling When the target transport amount includes a transport amount that is less than or equal to the minimum transport amount that can be controlled by this encoder pulse, the transport amount that is less than or equal to the minimum transport amount is transported based on the number of pulses applied to the pulse motor. Control And a control means.
[0017]
In the invention of claim 4, the control means corrects the transport distance error of less than one unit of quantization by the number of input pulses of the pulse motor, and performs accurate print medium transport.
[0018]
(5) The invention of claim 5 for solving the problem is Encoder 5. The printer according to claim 4, wherein a belt-like member that carries a repetitive pattern of a binary signal and is conveyed simultaneously with the print medium by the conveying unit is used.
[0019]
In the invention of claim 5, Encoder However, the transport distance is quantized using a belt-like member that carries a repetitive pattern of binary signals and is transported simultaneously with the print medium.
(6) The invention of claim 6 for solving the problem is Encoder 5. The printer according to claim 4, wherein a disk-shaped member that carries a repetitive pattern of binary signals and rotates simultaneously with the rotating member is used.
[0020]
In the invention of claim 6, Encoder However, the transport distance is quantized using a disk-shaped member that carries a repetitive pattern of binary signals and rotates simultaneously with the rotating member for transporting the print medium.
[0021]
(7) The invention of claim 7 for solving the problem is characterized in that the print head performs printing while moving in a direction crossing the transport direction of the print medium. The printer according to claim 6.
[0022]
According to the seventh aspect of the present invention, the print head performs printing while moving in a direction crossing the transport direction of the print medium.
(8) The invention of claim 8 for solving the problem is characterized in that the print head is a line head that covers a print range in a direction perpendicular to the transport direction of the print medium. A printer according to any one of claims 6 to 6.
[0023]
In the invention of claim 8, the print head prints at once the print range in the direction perpendicular to the print medium conveyance direction.
(9) The invention according to claim 9 for solving the problem is the printer according to any one of claims 4 to 8, wherein the print head is a liquid discharge head.
[0024]
According to the ninth aspect of the present invention, the print head performs printing by discharging liquid.
(10) The invention according to claim 10 for solving the problem is the printer according to any one of claims 4 to 8, wherein the print head is a thermal head.
[0025]
In the invention of claim 10, the print head performs printing by a thermal method.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiment. Although an example in which the print medium is paper will be described, the print medium is not limited to paper, and includes cloth, non-woven fabric, plastic film, and all other media capable of carrying a recorded visible image.
[0027]
FIG. 1 shows a schematic configuration of the inkjet printer 100. This apparatus is an example of an embodiment of a printer of the present invention. As shown in FIG. 1, in this apparatus, conveying rollers 101 and 103, which are conveying members of a recording sheet P for recording an image or the like, have shafts 102 and 104, respectively, and are rotatably supported by support means (not shown). Yes. The recording paper P is an example of an embodiment of a print medium in the present invention.
[0028]
A drive motor M for rotating the transport roller 101 to transport the recording paper P is connected to the shaft 102 of the transport roller 101. The drive motor M is a pulse motor. The recording paper P fed from a paper feeding unit (not shown) is wound around a part of the transport roller 101 and transported in the sub-scanning direction indicated by an arrow Y in the figure. The portion composed of the conveyance rollers 101 and 103 and the drive motor M is an example of an embodiment of the conveyance means in the present invention. The conveyance roller 101 is an example of an embodiment of a rotating member in the present invention.
[0029]
A recording head 108 is mounted on the guide member 109 so as to be movable in the main scanning direction (direction of arrow X in the figure) perpendicular to the sub-scanning direction of the recording paper P. The recording head 108 is an example of an embodiment of a print head in the present invention. Moreover, it is an example of the embodiment of the liquid discharge head in the present invention. In order to reciprocate the recording head 108 with the width of the recording paper P, the recording head 108 is fixed to a part of the drive wire 111 suspended from the pulleys 112 and 113, the pulley 113 is connected to the motor M1, and driven by the motor M1. The recording head 108 is driven via the wire 111.
[0030]
The configuration of the recording head 108 is such that a plurality of ejection ports (nozzles) (not shown) for ejecting ink droplets are provided on the lower surface of the recording head 108 facing the recording paper P, and image signals given from a signal supply unit (not shown), etc. Accordingly, ink droplets are ejected from the ejection port, and an image or the like is formed on the recording paper P.
[0031]
The plurality of nozzles of the recording head 108 are arranged along the sub-scanning direction. The number of nozzles is, for example, 64, and the pitch of the array is, for example, 360 dpi. As a result, recording is performed on a belt-like region having a width of 4.5 mm in the sub-scanning direction by one main scanning of the recording head 108.
[0032]
Between the transport roller 101 and the transport roller 103, a detected member 105 configured in a belt shape with, for example, a PET film or the like is wound around the transport direction of the recording paper P, that is, the sub-scanning direction. As a result, the detected member 105 moves at the same speed as the moving speed of the recording paper P and in parallel in the same direction. That is, the movement of the detected member 105 represents the conveyance of the recording paper P. The detected member 105 is an example of an embodiment of a belt-like member in the present invention.
[0033]
A detected mark 106 is provided on the detected member 105 over the entire length of the detected member 105. The detected mark 106 has a horizontal stripe pattern with a duty ratio of 50%, which is formed with a pitch corresponding to 360 dpi as one period.
[0034]
A detection member 107 having a fixed position is arranged in the vicinity of a part of the detection member 105 so as to detect the detection mark 106 on the detection member 105. A portion including the detected member 105, the detected mark 106, and the detecting member 107 is an example of the embodiment of the quantization means in the present invention.
[0035]
C is a control means, which takes in the output signal of the detection member 107 via the input / output means C1, and controls the motor M1 and the drive motor M via the input / output means C1 based on the received signal. The sub-scanning of the recording paper P is performed respectively. Thus, each time the recording head 108 performs main scanning once, the recording paper P is intermittently conveyed by 4.5 mm. The control means C is an example of an embodiment of the measuring means in the present invention. Moreover, it is an example of embodiment of the control means in this invention.
[0036]
A recording paper guide plate 114 is provided so as to face the recording head 108, and by guiding the recording paper P with this, the bending of the recording paper P under the recording head 108 is prevented. The recording paper P is discharged and conveyed to the outside by a pair of conveying rollers 110. The transport roller 110 is driven by a drive source (not shown).
[0037]
2 (a) and 2 (b) show an embodiment in which the detection mark 106 of the detected member 105 is detected using the detection member 107. FIG. In FIG. 2A, the light emitting unit 107A and the light receiving element 107B are provided in the detection member 107 with a predetermined angular relationship, and the light of the light emitting unit 107A is reflected by the detected member 105 and enters the light receiving element 107B. It has become. The reflected light incident on the light receiving element 107B is binary-modulated by the presence or absence of the detection mark 106 at the light reflection point as the detected member 105 moves, and a pulse signal based on the modulated light is input from the light receiving element 107B to the input / output means C1. Is input.
[0038]
In FIG. 2B, the light emitting portion 107A and the light receiving element 107B are arranged to face each other with the detected member 105 interposed therebetween. Incident light of the light receiving element 107B is binary-modulated in accordance with the presence or absence of the detection mark 106 at the light transmission point as the detected member 105 moves, and a pulse signal based on this is input from the light receiving element 107B to the input / output means C1. Is input.
[0039]
The detection member 107 generates a pulse train signal (encoder pulse) as shown in FIG. 3A by the movement of the detection member 105 accompanying the conveyance of the recording paper P. The encoder pulse corresponds to the horizontal stripe pattern which is the mark 106 to be detected, and one period corresponds to 360 dpi, and the duty ratio is 50%. Thereby, the interval (edge interval) between the rising edge and the falling edge of the encoder pulse corresponds to a distance of 35 μm (exactly 35.2777 μm). That is, the transport distance is quantized every 35 μm.
[0040]
The control means C counts the number of edges of the encoder pulse to recognize the transport distance of the recording paper P, and based on this, controls so that the transport distance per time in the sub-scanning direction is 4.5 mm. Since the transport distance of 4.5 mm corresponds to 128 edges in the encoder pulse, the control means C continuously transports the recording paper P while the count value of the encoder pulse edge is less than 128 after the start of transport. When it reaches, transport stops.
[0041]
The recording paper P is conveyed by applying a driving pulse to a driving motor M which is a pulse motor. The transport system including the drive motor M and the transport roller 101 is configured to generate a transport distance of 35 μm with 24 pulses, for example. The relationship between the drive pulse and the encoder pulse at this time is as shown in FIG. 3B, for example, and the edge interval of the encoder pulse corresponds to 24 drive pulses. Thus, 4.5 mm conveyance corresponding to 128 edges of the encoder pulse is performed by 3072 drive pulses. This results in 1.46 μm transport per drive pulse.
[0042]
As described above, since the transport distance of the recording paper P is controlled based on the encoder pulse detected from the detected member 105 transported together with the recording paper P, the transport of the recording paper P in the sub-scanning direction is accurate. To be done. Accordingly, the recorded image or the like does not have a white spot or the like, and a high-quality image or the like can be obtained.
[0043]
By the way, at the actual use site of this apparatus, the thickness of the recording paper P and the thickness of the member to be detected 105 may not exactly match due to variations in the thickness of the recording paper P. In such a case, An error occurs between the transport distance obtained from the encoder pulse and the actual transport distance of the recording paper P.
[0044]
If such an error is 0.3%, for example, a transport distance error of 13.5 μm per transport distance of 4.5 mm. Such a transport distance error may cause quality degradation of a recorded image or the like, but since this distance error is smaller than an encoder pulse quantization unit of 35 μm, it cannot be detected using an encoder pulse.
[0045]
Therefore, in such a case, the number of drive pulses per sub-scan given to the drive motor M according to the difference between the actual transport distance of the recording paper P measured in advance and the nominal transport distance obtained from the encoder pulse. Adjust.
[0046]
Hereinafter, correction of the conveyance distance error will be described. It is assumed that the control means C continuously transports the recording paper P while counting encoder pulses, and transports the nominal transport distance (4.5 mm) when the counted value reaches 128 edges. However, if the transport distance error is, for example, −0.3%, the actual transport distance is 13.5 μm shorter than the target distance. Therefore, the control means C gives nine additional drive pulses to the drive motor M for further conveyance of 13.5 μm. As a result, the sheet is additionally conveyed by 13.5 μm, the error is corrected, and the target conveyance distance is reached.
[0047]
At this time, the relative position of the detection mark 106 with respect to the detection member 107 is shifted by 13.5 μm by such distance error correction. Then, the next conveyance is started from this state.
[0048]
The next transport is also performed until the measured value of the encoder pulse reaches 128 edges, but the transport distance for 128 edges is 13.5 μm shorter than the target distance as described above. Since the first edge occurs at a transport distance shorter by 13.5 μm due to the point shift, the transport distance is eventually 27 μm shorter than the target value. Therefore, the control means C additionally inputs 18 drive pulses to the drive motor M for further transporting 27 μm so that the transport distance of the recording paper P matches the target value.
[0049]
Thereafter, in the same manner, error correction pulses that are sequentially accumulated by nine are added, and the conveyance distance error in each sub-scan is corrected. Since one section of the encoder pulse edge corresponds to 24 pulses, the accumulated value is decreased by 24 every time it exceeds 24, and the remaining 9 is accumulated by 9. In this way, by correcting the conveyance distance error less than the quantization unit of the encoder pulse, extremely accurate sub-scanning is performed, so that an extremely high quality printed matter can be obtained.
[0050]
In the above embodiment, the detection member 105 in which a plurality of detection marks 106 are formed is wound around the conveyance roller 101 that conveys the recording paper P, and the detection mark 106 of the detection member 105 is detected by the detection member 107. Although detection is performed, for example, marks on the cylindrical surface or cylindrical end surface of the conveyance roller 101 where the recording paper P is not conveyed are provided at regular intervals corresponding to the detection mark 106, and the mark is detected by the detection member 107. , And the drive motor M may be controlled by the control means C based on the detection.
[0051]
FIG. 4 shows a schematic configuration of an inkjet printer 100 employing such a method. This inkjet printer 100 is an example of an embodiment of a printer of the present invention. In this apparatus, the same parts as those shown in FIG. As shown in the figure, in the inkjet printer 100, a conveyance roller 101, which is a cylindrical conveyance member, is rotatably provided to convey the recording paper P.
[0052]
In order to convey the recording paper P by rotating the conveyance roller 101 on the shaft 102 of the conveyance roller 101, the gear G1 is fixedly provided on the shaft 102, and the gear G1 is driven. The drive gear G is meshed with the gear G1. The recording paper P is fed from a paper feeding unit (not shown) and is brought into contact with a part of the transport roller 101 to transport the recording paper P. That is, the recording paper P is conveyed in the sub scanning direction. A portion composed of the conveyance roller 101, the gear G1, the drive gear G, and the drive motor M2 is an example of an embodiment of the conveyance means in the present invention.
[0053]
A disc-shaped detection member 115 having a plurality of detection slits 116 formed around the circumference is fixedly provided on the shaft 102 of the conveyance roller 101 and is rotated together with the conveyance roller 101. The detected member 115 is an example of an embodiment of a disk-shaped member in the present invention. A detection member 117 for detecting the detection slit 116 is provided adjacent to the detection member 115. The slits 116 to be detected are formed with a pitch of 360 dpi, for example, but are schematically shown in FIG. The relationship between the detected member 115 and the detecting member 117 is the same as that shown in FIGS. 2 (a) and 2 (b). The portion composed of the detection member 115 and the detection member 117 is an example of the embodiment of the quantization means in the present invention.
[0054]
A recording head 108 is mounted on the guide member 109 so that it can move in the main scanning direction perpendicular to the feeding direction of the recording paper P. The recording head 108 is fixed to a part of the drive wire 111 wound around the pulleys 112 and 113 so that the recording head 108 can reciprocate within the width of the recording paper P, the pulley 113 is connected to the motor M1, and the motor M1 The recording head 108 is reciprocated through the drive wire 111 by driving. The configuration of the recording head 108 is the same as that of the recording head 108 in FIG.
[0055]
C is a control means which receives a detection signal from the detection member 117 via the input / output means C1 and controls the drive motor M2 and the motor M1 based on the detection signal. A recording paper guide plate 114 is provided opposite to the recording head 108 to prevent the recording paper P from being bent under the recording head 108. The recording paper P is discharged to the outside by a pair of transport rollers 110.
[0056]
In this apparatus, the detected member 115 and the detecting member 117 perform the same operation as the detected member 105 and the detecting member 107 in the apparatus shown in FIG. 1, and measure the transport distance of the recording paper P in the sub-scanning direction. Used. Then, recording of an image or the like is performed with high quality by carrying control and error correction similar to those of the apparatus shown in FIG.
[0057]
The above is an example in which printing is performed by moving the recording head 108 in the main scanning direction. The recording head 108 has a size that covers the entire range in the main scanning direction, and prints the range all at once. Of course.
[0058]
Needless to say, the recording head 108 is not limited to the liquid discharge head as described above, and may perform recording by other methods such as a thermal head, an optical head, or an impact head.
[0059]
In addition, although an example in which the mark to be detected is an optical mark has been shown, the present invention is not limited thereto, and may be another type of mark such as a magnetic mark.
[0060]
【The invention's effect】
As described above in detail, in the first aspect of the invention, the control means corrects the transport distance error of less than one unit of quantization by the number of input pulses of the pulse motor, and performs accurate print medium transport. Therefore, it is possible to realize a print medium conveying apparatus that accurately conveys a print medium.
[0061]
In the invention of claim 2, Encoder Thus, since the transport distance is quantized using the belt-shaped member that carries the binary signal repeating pattern and is transported simultaneously with the print medium, the print medium transport distance can be accurately measured.
[0062]
In the invention of claim 3, Encoder Since the transport distance is quantized using a disk-shaped member that carries a repetitive pattern of binary signals and rotates simultaneously with the rotating member for transporting the print medium, the print medium transport distance can be accurately measured. Can do.
[0063]
In the invention of claim 4, since the transport means error of less than one unit of quantization is corrected by the number of input pulses of the pulse motor by the control means, and the print medium is accurately conveyed, the print medium is accurately It is possible to realize a printer that performs high-quality printing while being conveyed to the printer.
[0064]
In the invention of claim 5, Encoder However, since the transport distance is quantized using a belt-like member that carries a binary signal repetitive pattern and is transported simultaneously with the print medium, the print medium transport distance can be accurately measured.
[0065]
In the invention of claim 6, Encoder Since the transport distance is quantized using a disk-shaped member that carries a repetitive pattern of binary signals and rotates simultaneously with the rotating member for transporting the print medium, the print medium transport distance can be accurately measured. Can do.
[0066]
According to the seventh aspect of the present invention, it is possible to realize a printer that performs high-quality printing by moving the print head in a direction crossing the print medium conveyance direction.
[0067]
According to the eighth aspect of the present invention, it is possible to realize a printer that performs high-quality printing by printing at once the print range in the direction perpendicular to the conveyance direction of the print medium with the line head.
[0068]
Further, according to the ninth aspect of the present invention, it is possible to realize a printer that performs high-quality printing by discharging liquid.
In the invention of claim 10, a printer that performs high-quality printing by a thermal method can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an apparatus according to an example of an embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating a relationship between a detection member and a member to be detected in an apparatus according to an example of an embodiment of the present invention.
FIG. 3 is a waveform diagram of a detection signal of a detection member in an apparatus according to an example of an embodiment of the present invention.
FIG. 4 is a schematic configuration diagram of an example of an apparatus according to an embodiment of the present invention.
FIG. 5 is a schematic configuration diagram of an example of a conventional apparatus.
FIG. 6 is a conceptual diagram of printing by an example of a conventional apparatus.
[Explanation of symbols]
P Recording paper
M drive motor
101 Conveyor roller
105 Detected member
106 Mark for detection
107 Detection member
108 Recording head
C1 input / output means
C Control means

Claims (10)

Conveying means for conveying the print medium by a rotating member that rotates using a pulse motor as a drive source;
Encoder pulses are generated in response to the rotation of the rotating member, and encoder pulses are generated at intervals longer than the moving distance of the rotating member rotating on the print medium conveyance surface by applying one pulse to the pulse motor. A designed encoder ,
While controlling the conveyance of the print medium based on the encoder pulse, and the target conveyance amount includes a conveyance amount less than the minimum conveyance amount that can be controlled by this encoder pulse, Control means for controlling the conveyance of the print medium based on the number of pulses applied to the pulse motor ;
A print medium conveying apparatus comprising: The encoder uses a belt-like member that carries a repeating pattern of binary signals and is conveyed simultaneously with the print medium by the conveying means.
The print medium conveying apparatus according to claim 1. The encoder uses a disk-shaped member that carries a repeating pattern of binary signals and rotates simultaneously with the rotating member.
The print medium conveying apparatus according to claim 1. A printer that prints on a print medium that is conveyed step by step by a certain distance with a print head,
Conveying means for conveying the print medium by a rotating member that rotates using a pulse motor as a drive source;
Encoder pulses are generated in response to the rotation of the rotating member, and encoder pulses are generated at intervals longer than the moving distance of the rotating member rotating on the print medium conveyance surface by applying one pulse to the pulse motor. A designed encoder ,
While controlling the conveyance of the print medium based on the encoder pulse, and the target conveyance amount includes a conveyance amount less than the minimum conveyance amount that can be controlled by this encoder pulse, Control means for controlling the conveyance of the print medium based on the number of pulses applied to the pulse motor ;
A printer comprising: The encoder uses a belt-like member that carries a repeating pattern of binary signals and is conveyed simultaneously with the print medium by the conveying means.
The printer according to claim 4. The encoder uses a disk-shaped member that carries a repeating pattern of binary signals and rotates simultaneously with the rotating member.
The printer according to claim 4. The print head performs printing while moving in a direction crossing the transport direction of the print medium.
The printer according to any one of claims 4 to 6, wherein: The print head is a line head that covers a print range in a direction perpendicular to the conveyance direction of the print medium.
The printer according to any one of claims 4 to 6, wherein: The print head is a liquid ejection head;
The printer according to any one of claims 4 to 8, wherein the printer is any one of the above. The print head is a thermal head;
The printer according to any one of claims 4 to 8, wherein the printer is any one of the above.

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