Transport Apparatus and Recording Apparatus
A transport apparatus includes a plurality of rollers that transport a medium, a detection unit that detects a rotation amount of each of the rollers, and a control unit that controls driving of each of the rollers. The control unit controls the driving of each of the rollers using a correction value that corresponds to a rotation amount from an origin position of the corresponding roller.
1. Technical Field
The present invention relates to transport apparatuses and recording apparatuses.
2. Related Art
There is a known recording apparatus in which a plurality of rollers for transporting a recording medium are provided, and the recording apparatus includes a transport control unit that controls the transport by applying a correction value to a roller, among the plurality of rollers, that is contributing to the transport, in each of transport regions of the recording medium (see JP-A-2012-101547, for example).
However, the stated apparatus has a problem in that the correction value that is applied is calculated based on a combination of a region of the recording medium, whose dimensions and the like are constant, and a roller, and thus it is difficult to calculate the correction value if the recording paper, the rollers, or the like are changed.
SUMMARYHaving been conceived in order to solve at least part of the aforementioned problems, an advantage of the invention is that a transport apparatus and a recording apparatus can be implemented as the following aspects or application examples.
Application Example 1A transport apparatus according to this application example includes a plurality of rollers that transport a medium, a detection unit that detects a rotation amount of each of the rollers, and a control unit that controls driving of each of the rollers, the control unit controlling the driving of each of the rollers using a correction value that corresponds to a rotation amount from an origin position of the corresponding roller.
The medium is transported by the plurality of rollers. Here, there are cases where each roller used to transport the medium has an eccentricity amount unique to that roller. In such a case, the eccentricity in each roller produces variation in the feed amount of the medium. However, even if the rotation of a given roller is controlled based on a correction value for transport fluctuation in that roller, the medium is transported by a plurality of rollers, and thus the influence of transport fluctuation in the other rollers produces variation in the transport amount of the medium in the overall system that transports the medium. Accordingly, according to the aforementioned configuration, the respective rollers are synchronized by managing origin positions of the rollers, and correction is carried out using correction values that correspond to rotation amounts from the origin positions of the respective rollers used to transport the medium. Through this, it is easy to calculate correction for the plurality of rollers in the overall transport system, and thus the precision with which the medium is transported can be increased.
Application Example 2In the transport apparatus according to the aforementioned application example, the plurality of rollers include an upstream-side roller and a downstream-side roller in a transport path of the medium.
According to this configuration, the correction is carried out using correction values corresponding to rotation amounts from the origin positions of the upstream-side roller and the downstream-side roller used to transport the medium, and thus the precision with which the medium is transported can be increased.
Application Example 3In the transport apparatus according to the aforementioned application example, a circumference of the upstream-side roller is an integral multiple of a circumference of the downstream-side roller.
According to this configuration, it is easy to synchronize the upstream-side roller and the downstream-side roller, and correction control management is simplified as a result.
Application Example 4In the transport apparatus according to the aforementioned application example, a distance between a position at which the upstream-side roller applies a transport force to the medium and a position at which the downstream-side roller applies a transport force to the medium is an integral multiple of the circumference of the upstream-side roller.
According to this configuration, the position at which the upstream-side roller applies the transport force to the medium matches the position at which the downstream-side roller applies the transport force to the medium when the medium is transported downstream. This makes the correction control even easier.
Application Example 5A recording apparatus according to this application example includes a transport apparatus having a plurality of rollers that transport a medium, a detection unit that detects a rotation amount of each of the rollers, and a control unit that controls driving of each of the rollers using a correction value that corresponds to a rotation amount from an origin position of the corresponding roller, and a recording unit, the plurality of rollers being located upstream from the recording unit in a transport direction.
According to this configuration, in the transport apparatus, the respective rollers are synchronized by managing origin positions of the rollers, and correction is carried out using correction values that correspond to rotation amounts from the origin positions of the respective rollers used to transport the medium. Through this, it is easy to calculate correction for the plurality of rollers in the overall transport system, and thus the precision with which the medium is transported can be increased. Furthermore, the medium is transported relative to the recording unit by stable transport amounts, which makes it possible to form (record) high-resolution images.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the appended drawings depict the measurements of the various members and the like as different from their actual measurements in order to illustrate those members and the like at recognizable sizes.
First, the configuration of a recording apparatus will be described. The recording apparatus includes a transport apparatus having a plurality of rollers that transport a medium, a detection unit that detects a rotation amount of each of the rollers, and a control unit that controls driving of each of the rollers using a correction value that corresponds to a rotation amount from an origin position of the corresponding roller, as well as a recording unit; the plurality of rollers are located upstream from the recording unit in a transport direction. This will be described in detail hereinafter.
As illustrated in
The carriage 42 is moved back and forth in the main scanning direction by the carriage motor 54 driving the carriage belt 58. A carriage position sensor 49 that detects a position of the carriage 42 in the main scanning direction is attached to a rear surface side of the carriage 42. The carriage position sensor 49 is constituted by a linear-type optical scale 49a disposed along the carriage guide 52 on a frame 59, and an optical sensor 49b that is attached to the rear surface of the carriage 42 so as to face the optical scale 49a and that optically reads the optical scale 49a. A paper width detection sensor 43 for detecting a width of the roll paper P is attached to a bottom surface of the carriage 42. Although not illustrated in detail, the paper width detection sensor 43 is configured as a photodetector that includes a light-emitting element such as a light-emitting diode and a light-receiving element such as a phototransistor, and by emitting light from the light-emitting element and receiving light reflected by the roll paper P using the light-receiving element, converts a detected amount of light corresponding to a light intensity into an electrical signal as a voltage. The platen 48 and the roll paper P have different light reflectances, and thus by moving the carriage 42 across the roll paper P in the main scanning direction while the light-emitting element emits light, the paper width detection sensor 43 can detect left and right ends of the roll paper P based on the electrical signal obtained by the light-receiving element. The paper width can be obtained by finding a difference between two positions of the carriage 42 detected by the carriage position sensor 49 when the paper width detection sensor 43 has detected the left and right ends of the roll paper P.
Next, the configuration of the transport apparatus will be described.
Meanwhile, as illustrated in
When, in the recording apparatus 20, image data is inputted to the data/command analysis controller 22 in accordance with a print instruction from the control PC 10, the data/command analysis controller 22 resizes the inputted image (RGB) data and carries out color conversion for converting that data into CMYK data, generates print data by binarizing the post-conversion CMYK data through carrying out halftone processing thereon, and sends the print data to the head controller 24 and the printing mechanism/transport controller 30. The printing mechanism/transport controller 30 then rotationally drives the first roller 141 and the second roller 241 using a driving unit so as to transport the roll paper P on the platen 48, and drives the carriage motor 54 so as to move the carriage 42 back and forth; the head controller 24 then causes the respective colors of ink to be ejected by driving the print head unit 44 at ejection timings based on the print data. A color image is formed on the roll paper P as a result.
Next, configurations in the vicinities of the first roller 141 and the second roller 241 will be described.
First, the configuration in the vicinity of the first roller 141 will be described. Specifically, the configuration of a driving mechanism 151 that rotates the first roller 141 and the configuration of a first detection unit 171 serving as a detection unit that detects a rotation amount of the first roller 141 will be described.
First, the configuration of the driving mechanism 151 will be described. As illustrated in
Next, the configuration of the first detection unit 171 will be described. As illustrated in
Next, a configuration in the vicinity of the second roller 241 will be described. Specifically, the configuration of a driving mechanism 251 that rotates the second roller 241 and the configuration of a second detection unit 271 serving as a detection unit that detects a rotation amount of the second roller 241 will be described.
First, the configuration of the driving mechanism 251 will be described. As illustrated in
Next, the configuration of the second detection unit 271 will be described. As illustrated in
Next, the configuration of a control unit of the transport apparatus will be described.
When the light-receiving unit 173b of the first rotary encoder 171 outputs an electrical signal to the control unit 30 as a detection signal, the control unit 30 detects a rotational position of the first roller 141 that is fixed to the slitted disk 172 based on a square wave output signal from the encoder, which is obtained by carrying out waveform shaping on a detection signal formed of pulse signals produced by the light-receiving unit 173b when light has passed through the portions of the position detection slits 172a. In addition, the control unit 30 detects an origin position of the first roller 141 that is fixed to the slitted disk 172 based on a detection signal produced by the light-receiving unit 173b when light has passed through the portion of the origin position detection slit 172b. Meanwhile, when the light-receiving unit 273b of the second rotary encoder 271 outputs an electrical signal to the control unit 30 as a detection signal, the control unit 30 detects a rotational position of the second roller 241 that is fixed to the slitted disk 272 based on a square wave output signal from the encoder, which is obtained by carrying out waveform shaping on a detection signal formed of pulse signals produced by the light-receiving unit 273b when light has passed through the portions of the position detection slits 272a. In addition, the control unit 30 detects an origin position of the second roller 241 that is fixed to the slitted disk 272 based on a detection signal produced by the light-receiving unit 273b when light has passed through the portion of the origin position detection slit 272b.
The configuration is such that when the detection signal is received from the first rotary encoder 171, the control unit 30 outputs, to the first drive motor 162, a driving control signal that has undergone a correction process based on first correction data stored in the storage unit of the control unit 30. The first correction data stored in the storage unit is tabled data containing differential amounts between theoretical and actual paper feed amounts of the first roller 141 produced by the first driving motor 162. Likewise, the configuration is such that when the detection signal is received from the second rotary encoder 271, the control unit 30 outputs, to the second drive motor 262, a driving control signal that has undergone a correction process based on second correction data stored in the storage unit of the control unit 30. Here, the second correction data is tabled data containing differential amounts between theoretical and actual paper feed amounts of the second roller 241 produced by the second drive motor 262. Note that the first and second correction data in the tables are not limited to the storage unit provided in the control unit 30, and the configuration may be such that the data can be communicated to the printing mechanism/transport controller 30 (the control unit 30) using an external storage unit such as a magnetic storage device, an optical disk, or the like.
Next, a method for controlling the recording apparatus and the transport apparatus will be described. However, variation in transport amounts of the roll paper P will be described before describing the method for controlling the recording apparatus and the transport apparatus.
In the recording apparatus 20 (the transport apparatus 60) according to this embodiment, the feed amount of the roll paper P relative to the rotational position of the first roller 141 is measured; then, as illustrated in
Meanwhile,
In the recording apparatus 20 (the transport apparatus 60) according to this embodiment, the feed amount of the roll paper P relative to the rotational position of the second roller 241 is measured; then, as illustrated in
Meanwhile,
Next, the method for controlling the recording apparatus and the transport apparatus will be described. As mentioned above, eccentricity arises in the first roller 141 and the second roller 241, which necessitates a process for correcting transport fluctuation; however, for example, in the case where the transport fluctuation of the first roller 141 is great, even if the transport fluctuation is corrected for the second roller 241 alone, the correction for the second roller 241 alone will be insufficient and transport variation for the roll paper P will arise. Accordingly, in this embodiment, the control unit 30 controls the driving of the first roller 141 and the second roller 241 using correction values that correspond to rotation amounts from the respective origin positions of the first roller 141 and the second roller 241. This will be described in detail hereinafter.
Here, the control unit 30 detects the origin position of the first roller 141 based on the detection signal from the first rotary encoder 171, and outputs the driving control signal to the first drive motor 162 so as to rotate the first roller 141 from that detected origin position by an instructed rotation amount based on a transport instruction according to the print instruction and transport the roll paper P as a result. Likewise, the control unit 30 detects the origin position of the second roller 241 based on the detection signal from the second rotary encoder 271, and outputs the driving control signal to the second drive motor 262 so as to rotate the second roller 241 from that detected origin position by an instructed rotation amount based on a transport instruction according to the print instruction and transport the roll paper P as a result.
At this time, the control unit 30 retrieves the first correction data and the second correction data from the storage unit, calculates a difference between the differential amounts of the theoretical feed amounts and the actual feed amounts of the roll paper P by the first roller 141 and the second roller 241 based on the first correction data and the second correction data, finds a corrected rotation amount by correcting the instructed rotation amount so as to eliminate the difference between the differential amounts, and outputs the driving control signal so that the first roller 141 and the second roller 241 rotate by the corrected rotation amount.
Specifically, as illustrated in
For example, as illustrated in
Likewise, as illustrated in
The roll paper P is then transported toward the print head unit 44 by the first roller 141 and the second roller 241 rotating. Ink droplets are then ejected from the nozzles of the print head unit 44 onto the transported roll paper P. An image is formed on the roll paper P as a result.
According to the embodiment described thus far, the following effects can be obtained.
The instructed rotation amount based on a transport instruction is corrected using the first and second correction data, the corrected rotation amounts from the respective origin positions synchronized between the first roller 141 and the second roller 241 are found, the first roller 141 and the second roller 241 are rotated by carrying out driving control on the first drive motor 162 and the second drive motor 262. Through this, variations in the feed amount of the roll paper P when transporting the roll paper P using the first roller 141 and the second roller 241 can be reduced. Reducing variation in the feed amount of the roll paper P makes it possible to carry out high-resolution printing (image forming).
Note also that the invention is not limited to the embodiment described above, and many variations and alterations thereof are possible as well. Such variations will be described hereinafter.
Variation 1Although the aforementioned embodiment describes the circumference of the first roller 141 as being an integral multiple of the circumference of the second roller 241, a distance between a position P1 at which the first roller 141 applies a transport force to the roll paper P and a position P2 at which the second roller 241 applies a transport force to the roll paper P may further be an integral multiple of the circumference of the first roller 141, as illustrated in
Although the aforementioned embodiment describes the circumference of the first roller 141 as being an integral multiple of the circumference of the second roller 241, the invention is not limited thereto. For example, the relationship between the circumferences need not be one in which the circumference of the first roller 141 is an integral multiple of the circumference of the second roller 241. Even with such a configuration, the transport fluctuation is corrected for the first roller 141 and the second roller 241 using the origin position as a reference, and thus the precision with which the roll paper P is transported can be increased.
Variation 3Although the aforementioned embodiment describes correcting the driving signals for the first drive motor 162 and the second drive motor 262 in accordance with the correction of transport fluctuation in the first roller 141 and the second roller 241, the invention is not limited thereto. For example, as illustrated in
Although the aforementioned embodiment describes an example in which the medium is the roll paper P, the invention is not limited thereto. For example, the medium may be single sheets of paper that are separated one sheet at a time. The same effects as those described above can be obtained even with such a configuration.
The entire disclosure of Japanese Patent Application No.2014-153661, filed Jul. 29, 2014 is expressly incorporated by reference herein.
Claims
1. A transport apparatus comprising:
- a plurality of rollers that transport a medium;
- a detection unit that detects a rotation amount of each of the rollers; and
- a control unit that controls driving of each of the rollers,
- wherein the control unit controls the driving of each of the rollers using a correction value that corresponds to a rotation amount from an origin position of the corresponding roller.
2. The transport apparatus according to claim 1,
- wherein the plurality of rollers include an upstream-side roller and a downstream-side roller in a transport path of the medium.
3. The transport apparatus according to claim 2,
- wherein a circumference of the upstream-side roller is an integral multiple of a circumference of the downstream-side roller.
4. The transport apparatus according to claim 2,
- wherein a distance between a position at which the upstream-side roller applies a transport force to the medium and a position at which the downstream-side roller applies a transport force to the medium is an integral multiple of the circumference of the upstream-side roller.
5. A recording apparatus comprising:
- a transport apparatus including a plurality of rollers that transport a medium, a detection unit that detects a rotation amount of each of the rollers, and a control unit that controls driving of each of the rollers using a correction value that corresponds to a rotation amount from an origin position of the corresponding roller; and
- a recording unit,
- wherein the plurality of rollers are located upstream from the recording unit in a transport direction.
Type: Application
Filed: Jul 13, 2015
Publication Date: Feb 4, 2016
Inventors: Tomohiro Yuda (Minowa-machi), Bunji Ishimoto (Matsumoto-shi)
Application Number: 14/797,366