JP4207892B2 - Slit pattern forming method and cylindrical jig - Google Patents

Description

The present invention relates to a slit pattern forming method for regularly forming a slit pattern that can be detected by an encoder on a conveyor belt that can be configured as a conveyor unit by being passed over a roller , and a cylinder that can be used in this method. Jochi again and again about.

In an image forming apparatus or the like, a transport unit that is used to transport a recording medium or the like includes a transport belt that is stretched between a driving roller and a driven roller.
In such a transport unit, in order to monitor the transport amount of the recording medium with an encoder, it is common to regularly form a slit pattern that can be detected by the encoder over the entire circumference of the transport belt (Patent Document 1, Patent Document 1). Patent Document 2). The “slit pattern” here refers to a pattern formed by forming physical slits, a pattern formed by forming different colors such as barcodes as optical slits, and positive and negative electrodes alternately. A pattern formed by forming a magnetized portion as a magnetic slit.
Japanese Patent Laid-Open No. 06-127037 Japanese Patent Laid-Open No. 08-211893

  As a specific method of forming the slit pattern described above, there is a method of sequentially forming slits along the entire circumference of the conveyor belt. In this method, however, errors are accumulated from the position where the slits are first formed. As a result, the positional relationship between the first slit and the last slit is likely to be greatly displaced. For this reason, in the transport unit using the transport belt formed with the slit pattern in this way, it is difficult to accurately monitor the transport amount.

  In addition, as a specific method for forming the slit pattern, there is a method in which a pattern member having a slit pattern formed in accordance with the circumference of the transport belt is attached to the transport belt. Since it is difficult to fit both ends of the pattern member exactly, the positional relationship between the slit at one end and the slit at the other end is likely to be shifted. Therefore, even in a transport unit using a transport belt formed with slit patterns in this way, it becomes difficult to accurately monitor the transport amount.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a technique for accurately forming a regular slit pattern on a transport belt and to transport a slit pattern thus formed. It is to be able to accurately monitor the transport amount using a belt.

  In order to solve the above-mentioned problem, the slit pattern forming method according to claim 1 is a slit for regularly forming a slit pattern detectable by an encoder on a conveyor belt which can be configured as a conveyor unit by passing over a roller. A pattern forming method, wherein the conveyor belt is fitted into a cylindrical jig whose outer diameter is equal to or larger than the inner diameter of the conveyor belt, and then contacts the inner peripheral surface of the conveyor belt in the cylindrical jig A slit pattern is formed on the conveyor belt by each of a plurality of slit forming portions regularly arranged along the outer peripheral surface.

  In such a slit pattern forming method, the slit pattern is formed by each of the plurality of slit forming portions in which the cylindrical jig is regularly arranged along the outer peripheral surface. Thus, the slit pattern is formed. In this case, it is not necessary to change or adjust the position of the conveyor belt fitted in the cylindrical jig. Therefore, unlike the method of sequentially forming slits around the entire circumference of the conveyor belt, errors are not accumulated from the position where the slits were first formed, and the first slit and the last slit formed. There will be no significant deviation in the positional relationship. In addition, unlike a method in which a pattern member formed with a slit pattern is attached to a conveyor belt, a slit pattern is formed later on the conveyor belt (inner or outer circumferential surface). The slits at both ends of the slit pattern formed in the above will not be displaced.

  As described above, according to the slit pattern forming method described above, a regular slit pattern can be formed on the transport belt more accurately than in the past. And if a conveyance unit is comprised using the conveyance belt in which the slit pattern was formed by such a method, a conveyance amount can be accurately monitored according to a regular slit pattern.

  Particularly, by arranging each slit forming portion in the cylindrical jig with high accuracy, a slit pattern can be formed on the conveyance belt with high accuracy, and the conveyance amount can be monitored with higher accuracy.

  The above-mentioned “conveyance unit” may be any unit that performs some kind of conveyance in a state where a conveyance belt is stretched around a roller. For example, the “conveyance unit” may be a unit for conveying a recording medium in an image forming apparatus. In addition, a unit for conveying an image to be transferred onto a recording medium such as an intermediate transfer belt in the image forming apparatus may be considered.

  The “slit pattern” is, for example, a pattern formed by forming physical slits on the conveyor belt (hereinafter referred to as “physical pattern”), and a striped pattern is formed along the length direction of the conveyor belt (printing or An optical (visual) pattern formed by coloring (hereinafter referred to as an “optical pattern”), and magnetically slitting the positive electrode and the negative electrode along the length direction of the conveying belt, thereby magnetically slitting this. And the like (hereinafter referred to as “magnetic pattern”).

  In addition, the slit forming portion described above may be any one that is regularly arranged along the outer peripheral surface that contacts the inner peripheral surface of the conveyance belt in the cylindrical jig. For example, the outer peripheral surface of the cylindrical jig It is conceivable to adopt a configuration provided in itself or a configuration provided in a positional relationship so as to surround the outer peripheral surface of the conveyance belt fitted in a cylindrical jig. Moreover, when forming a magnetic pattern as a slit pattern, it is also conceivable to employ a configuration arranged inside a cylindrical jig.

  In addition, the specific configuration for forming the slit pattern by the slit forming unit described above is not particularly limited. For example, when a physical pattern is formed as the slit pattern, the slit forming unit passes through the transport belt. The through-holes that can form physical slits are arranged at regular intervals along the outer peripheral surface of the cylindrical jig that comes into contact with the inner peripheral surface of the conveyor belt. A method of forming a physical slit pattern penetrating the conveyance belt by each slit forming portion in the cylindrical jig after fitting into the jig is conceivable.

If it is such a method, the slit penetrated at regular intervals by each slit formation part can be formed in a conveyance belt as a physical pattern.
Further, in the case of forming an optical pattern as a slit pattern, as the slit forming portion, a line forming portion capable of forming (coloring or printing) a line (a line along a direction intersecting the length direction) on the transport belt, The cylindrical jig that is arranged at regular intervals along the outer peripheral surface of the cylindrical jig that comes into contact with the inner peripheral surface of the conveyor belt is used. After the conveyor belt is fitted into the cylindrical jig, the cylindrical jig is used. A method of forming a striped optical slit pattern on the conveyor belt by each of the slit forming portions in FIG.

If it is such a method, the striped pattern formed at regular intervals by each slit formation part can be formed in a conveyance belt as an optical pattern.
In the case where a magnetic pattern is formed as the slit pattern, as described in claim 2, a magnetic field from the outside is provided along the inner peripheral surface of at least the outer peripheral surface of the cylindrical jig as the transport belt. A magnetized part that can be magnetized with a positive electrode and a magnetized part that can be magnetized with a negative electrode as the slit forming part. The belt is arranged at regular intervals along the outer peripheral surface that contacts the inner peripheral surface of the belt, and after the conveyor belt is fitted into the cylindrical jig, the slit in the cylindrical jig is used. Forming a magnetic slit pattern on the conveyor belt by magnetizing the magnetized part of the conveyor belt at regular intervals on the positive and negative electrodes by the forming unit, etc. The law can be considered.

With such a method, a pattern magnetized at regular intervals by the slit forming portions can be formed as a magnetic pattern on the transport belt.
Further, the cylindrical jig described above may have an outer diameter equal to or larger than the inner diameter of the transport belt, and may be the same outer diameter as the inner diameter of the transport belt. However, the state where the conveyor belt is stretched over the roller to form the conveyor unit is more tensioned by the roller than the normal state where the conveyor belt is not stretched over the roller and does not constitute the conveyor unit. The inner diameter may increase. In such a case, if the outer diameter of the cylindrical jig is matched with the inner diameter of the conveyor belt in the normal state, the conveyor belt actually formed with the slit pattern has a larger inner diameter due to the tension applied when the conveyor unit is configured. As a result, there is a possibility that the interval between the slits in the slit pattern becomes non-uniform.

  Therefore, as a cylindrical jig, the outer diameter of the cylindrical jig is larger than the inner diameter of the conveying belt in a normal state, and the conveying belt is used as the cylindrical jig. It is good to use the same inner diameter of the conveyor belt in the state where the conveyor unit is configured, and the conveyor belt extends along the outer diameter of the cylindrical jig and is fitted into the cylindrical jig. It is desirable.

  With such a method, when the slit pattern is formed, the conveyance belt has an inner diameter in a state in which the conveyance unit is configured, not in a normal state. Therefore, according to a state in which the conveyance unit is actually configured. A slit pattern may be formed.

  Therefore, even if the conveyance unit is configured by a conveyance belt that has actually formed a slit pattern and the inner diameter is increased by the tension at that time, it can be said that the slit pattern is formed in that state. It can prevent that the space | interval of each slit becomes non-uniform | heterogenous by a change.

  Further, as described above, when the conveyance belt is fitted into the cylindrical jig, the conveyance belt may be fitted as it is without adding any hand, but in that case, by adjusting the force when fitting it, The extension of the conveyor belt is uneven over the entire circumference, which can result in a gap in the spacing between the slits.

  As a device for preventing such a situation, for example, as described in claim 4, the conveyor belt is heated and expanded over the entire inner peripheral surface or outer peripheral surface of the conveyor belt. The cylindrical jig may be fitted into the cylindrical jig as being extended along the outer circumference.

  With such a method, heating the entire inner peripheral surface or outer peripheral surface of the conveyor belt facilitates uniform expansion of the conveyor belt over the entire circumference. It can be set as the state extended uniformly along the length. Therefore, the extension of the conveyor belt when fitted into the cylindrical jig is likely to be uniform over the entire circumference, thereby preventing the gap between the slits from being displaced.

  In this method, as a heating state when heating the conveyor belt, for example, the heating may be performed at a temperature equal to or higher than the temperature at which the inner diameter of the conveyor belt matches the outer diameter of the cylindrical jig. Further, after the conveyor belt is fitted in the cylindrical jig in this way, the slit pattern formation by the slit forming unit may be performed while the temperature of the conveyor belt is at a heated temperature. It may be performed in a state where the temperature of the conveyor belt is lowered to some extent, specifically, in a state where the temperature is lowered to a temperature suitable for forming a slit pattern by the slit forming unit.

  Further, the cylindrical jig according to claim 5 is a cylindrical jig used for regularly forming slit patterns detectable by an encoder on a conveyor belt that can be configured as a conveyor unit by being passed over rollers. A cylindrical jig body having an outer diameter equal to or larger than the inner diameter of the conveyor belt, and the jig contacting the inner peripheral surface of the conveyor belt when the conveyor belt is fitted into the jig body. And a plurality of slit forming portions for regularly forming a slit pattern on the transport belt.

  If it is such a cylindrical jig, it is suitable as a cylindrical jig used when forming a slit pattern in a conveyance belt by the slit pattern formation method in any one of Claims 1-4 mentioned above.

  In this cylindrical jig, the specific configuration of the slit forming portion is the same as described above. For example, when a physical pattern is formed as a slit pattern, the outer periphery of the jig body is used as the slit forming portion. The through portions that can pass through the transport belt along the surface to form physical slits may be arranged at regular intervals along the outer peripheral surface that contacts the inner peripheral surface of the transport belt. Further, when an optical pattern is formed as a slit pattern, a line (a line along the direction intersecting the length direction) to the conveyance belt is formed (colored) along the outer peripheral surface of the jig body as a slit forming portion. Alternatively, the printable line forming portions may be arranged at regular intervals along the outer peripheral surface in contact with the inner peripheral surface of the transport belt.

  Further, in the case of forming a magnetic pattern as the slit pattern, as described in claim 6, as the slit forming part, the magnetized part of the conveyor belt can be magnetized with a positive part and a negative part. Magnetized portions are arranged at regular intervals along the outer peripheral surface that comes into contact with the inner peripheral surface of the conveyor belt, and after the conveyor belt is fitted into the cylindrical jig, by the slit forming portion, Magnetized portions that are formed along an inner peripheral surface that contacts at least the outer peripheral surface of the cylindrical jig of the conveyor belt and are magnetized by receiving a magnetic field from the outside are provided at regular intervals on the positive electrode and the negative electrode, respectively. It is preferable to form a magnetic slit pattern on the conveyor belt by magnetizing.

  If comprised in this way, it is suitable as a cylindrical jig | tool used when forming a slit pattern in a conveyance belt with the slit pattern formation method of Claim 2 (and the claim which quotes Claim 2).

  Further, in each cylindrical jig described above, as described above, the outer diameter of the jig main body only needs to be equal to or larger than the inner diameter of the conveyor belt. It is preferable that the inner diameter of the conveyor belt is larger than the inner diameter of the conveyor belt, and the inner diameter of the conveyor belt in a state where the conveyor unit is configured by the conveyor belt.

  This latter configuration is suitable as a cylindrical jig for use in forming a slit pattern on the conveyor belt by the slit pattern forming method according to claim 3 (and claim claiming claim 3).

  In addition, in the cylindrical jig, for example, as described in claim 8, for the purpose of preventing the gap between the slits from being displaced when the conveying belt is fitted into the jig main body. It is preferable that the conveyor belt fitted in the jig is provided with a heating unit that can be heated and expanded over the entire inner peripheral surface or outer peripheral surface of the conveyor belt.

  If comprised in this way, it is suitable as a cylindrical jig | tool used when forming a slit pattern in a conveyance belt with the slit pattern formation method of Claim 4 (and the claim which quotes Claim 4).

  The heating unit in this configuration may have any configuration as long as it can be heated over the entire inner peripheral surface or outer peripheral surface of the conveyor belt. For example, it is arranged so as to surround the outer peripheral surface of the conveyor belt fitted in the jig main body so that the outer peripheral surface is entirely heated, or the outer peripheral surface of the jig main body functions as a heating unit. For example, a configuration in which the inner peripheral surface of the conveyor belt is heated as a whole is conceivable.

  Further, for the purpose of facilitating the work when the conveyor belt is fitted, the jig body described above, for example, as described in claim 9, from an area where the outer diameter is smaller than the inner diameter of the conveyor belt. It is good to make it the structure which provided the cylindrical taper part which changes continuously to the area | region which is the same as the outer diameter of the said jig | tool main body at the edge part side of the said jig | tool main body.

  If comprised in this way, when fitting a conveyance belt in a jig main part, it will first be fitted in a taper part, but since this taper part has an outer diameter of one end smaller than a conveyance belt, fitting of a conveyance belt is carried out. From this state, it is possible to easily fit into the jig main body by gradually extending the outer diameter of the conveyor belt and shifting toward the jig main body.

The slit pattern according to any one of claims 1 to 4, further comprising a transport belt that can be configured to be transported to a roller so that the transport amount can be accurately monitored according to a regular slit pattern. Depending on the forming method, a conveyor belt in which slit patterns that can be detected by an encoder are regularly formed may be used.

  Since the slit pattern is accurately formed by the slit pattern forming method according to any one of claims 1 to 4, the transport belt configured as described above is configured with a transport unit using the transport belt. The conveyance amount can be monitored accurately according to a regular slit pattern.

In addition, if a conveyance unit is formed by driving the conveyance belt described above and being driven around a driven roller, a regular slit pattern is accurately formed on the conveyance belt. Can do.

Further, the image forming apparatus may be configured to form an image on the recording medium while the recording medium is conveyed by the conveying unit described above .

  With this configuration, the transport unit can accurately monitor the transport amount according to the slit pattern formed on the transport belt with high accuracy. Since the displacement of each pixel constituting the formed image is reduced, the quality of the image formed on the recording medium can be improved.

The transport unit described above is not only applied as a transport unit, but also from a unit composed of a photosensitive belt that forms an electrostatic latent image, or from an intermediate transfer belt that transfers an electrostatic latent image visualized with a developer to a recording medium. It can also be applied as a unit.

1. Overall Configuration As shown in FIG. 1, a color laser printer (hereinafter simply referred to as “printer”) 1 has a paper tray 12 that can be attached and detached while recording paper p is set, and a recording paper p set in the paper tray 12. A paper feed roller 14 that extracts one sheet at a time, a pair of transport rollers 16 that transport the recording paper p extracted by the paper feed roller 14, a guide member 18 that guides the recording paper p transported by the transport roller 16, and a guide member 18 The image forming unit 20 that forms an image on the recording paper p conveyed through the sheet, a pair of paper discharge rollers 34 that discharge the recording paper p on which the image is formed by the image forming unit 20 to the discharge tray 32, and the like In the image forming apparatus.

  The image forming unit 20 includes an image forming unit 40 that forms an image on the recording paper p, and a position (fixing position) where the image forming unit 40 forms an image on the recording paper p conveyed via the guide member 18. ) And a fixing unit 60 for fixing the image formed on the recording paper p by heating and pressurizing the recording paper p.

  Among these, a plurality of the image forming units 40 are arranged along the conveyance direction of the recording paper p by the conveyance unit 50 (see the arrow in FIG. 1, the same applies hereinafter), each of which is a photosensitive drum 42 and the photosensitive drum. A charging unit 44 for charging 42, a scanner unit 46 for forming an electrostatic latent image on the photosensitive drum 42, a developing unit 48 for forming a developer image by attaching a developer to the photosensitive drum 42, and the like. Yes. Then, the developer image formed on the photosensitive drum 42 by the scanner unit 46 is transferred to the recording paper p conveyed by the conveying unit 50, whereby an image is formed on the recording paper p. . The image forming unit 40 can form images in different colors (in this embodiment, four colors of cyan (C), magenta (M), yellow (Y), and black (K)). It is.

  The charger 44 in the image forming unit 40 generates a corona discharge from a charging wire made of tungsten or the like, for example, to positively charge the surface of the photosensitive drum 42 to a positive polarity. It is a charger. The scanner unit 46 includes a laser generator and a lens that generate laser light for forming an electrostatic latent image on the surface of the photosensitive drum 42. Note that most of the scanner unit 46 shown in FIG. 1 is omitted, and only the part where the laser beam is finally emitted is shown. Thus, the scanner unit 46 forms an electrostatic latent image on the surface of the photosensitive drum 42 by causing the laser light emitted from the laser emitting unit to scan on the surface of the photosensitive drum 42, and the electrostatic latent image is conveyed. By being transferred onto the recording paper p conveyed by the unit 50, an image is formed on the surface of the recording paper p.

  The conveyance unit 50 is arranged on the downstream side in the conveyance path of the recording paper p, and is driven on the upstream side in the conveyance path of the recording paper p, a driving roller 52 that rotates by receiving power from a motor 84 described later. An endless conveying belt 56 that is stretched between the roller 54, the driving roller 52, and the driven roller 54, and a transfer roller 58 that is disposed at a position facing the photosensitive drum 42 in the image forming unit 40 via the conveying belt 56. Etc.

The fixing unit 60 includes a heating roller 62 in which a halogen lamp is accommodated along the axial direction of a metal base tube having a release layer formed on the surface, and a recording sheet p conveyed by the conveying unit 50 with the heating roller 62. It is constituted by a pressing roller 64 and the like that are conveyed toward the paper discharge roller 34 while being pressed between them. The halogen lamp accommodated in the heating roller 62 heats the surface of the heating roller 62 to a temperature (fixing temperature) at which the developer image transferred to the recording paper p can be fixed.
2. As shown in FIG. 2, the printer 1 includes a CPU 72 that controls the operation of the entire printer 1, a ROM 74 that stores processing procedures by the CPU 72, a RAM 76 that stores processing results by the CPU 72, and the like. A driver 78 for generating a command signal to each unit included is built in, and a control system is configured by these. The driver 78 drives a motor (80 to 86) for rotating rollers constituting the image forming unit 40, the transport unit 50, the fixing unit 60 and the like in addition to the paper feed roller 14, the transport roller 16, and the paper discharge roller 3. Drive circuit, a control circuit for controlling charging by the charger 44 in the image forming unit 40, laser irradiation by the scanner unit 46, and the like, and a drive circuit for applying a bias voltage to the photosensitive drum 42 as will be described later. Is.

  The conveyance of the recording paper p by the conveyance unit 50 is controlled by an encoder configured by a slit pattern formed on the inner peripheral surface of the conveyance belt 56 and a detector 59 that detects this slit pattern as will be described later. The rotation speed of the driving roller 52, that is, the conveying speed by the conveying belt 56 is controlled by feedback controlling the motor 84 for rotating the driving roller 52 based on the encoder signal indicating the slit pattern detected by the detector 59. Is configured to control.

When the CPU 72 receives an instruction to form an image from the outside (for example, an instruction from an operation unit (not shown), an instruction from another device connected via an interface (not shown), etc.), the CPU 72 stores the instruction in the ROM 74. The following processing is executed by controlling the operation of the entire printer 1 in accordance with the program being executed.
(1) First, each part of the printer 1 is initialized. During this initialization, heating of the heating roller 62 in the fixing unit 60 is also started.
(2) Next, in the image forming unit 40, after the surface of the photosensitive drum 42 is uniformly charged by the charger 44, the laser light modulated based on the image information of the image to be formed is output by the scanner unit 46. By irradiating the photosensitive drum 42, an electrostatic latent image is formed on the surface of the photosensitive drum 42.
(3) Next, in the image forming unit 40, a developer is applied to the surface of the photosensitive drum 42 by the developing unit 48 to visualize the electrostatic latent image on the surface of the photosensitive drum 42. (4) Thereafter, in the image forming unit 40, the photosensitive drum 42 is rotated to move the visualized visible image (developer image) to a predetermined transfer position.
(5) Further, the recording paper p is fed to the transport unit 50 by rotating the paper feed roller 14 and the transport roller 16, and the drive roller 52 of the transport unit 50 is rotated to perform recording by the transport belt 56. The conveyance of the paper p is started.
(6) Along with the conveyance of the recording paper p by the conveyance unit 50 in the processing so far, a predetermined bias voltage (transfer) is sequentially applied between the photosensitive drum 42 in the image forming unit 40 and the transfer roller 58 in the conveyance unit 50. By applying a bias voltage), a visible image visualized on the surface of the photosensitive drum 42 is transferred to the surface of the recording paper p.
(7) Thereafter, the pressure roller 64 in the fixing unit 60 is rotated to convey the recording paper p while being heated and pressurized, thereby fixing the visible image on the surface of the recording paper p.
(8) After repeating the procedures (2) to (7) according to the image information of the image to be formed, the recording paper p is discharged onto the discharge tray 32 by rotating the discharge roller 34. Then, the operation of each unit is terminated.
3. Method for Forming Slit Pattern on Conveying Belt 56 As described above, the conveying belt 56 of the conveying unit 50 is controlled in conveying speed based on the slit pattern formed on the surface thereof, and this conveying speed is accurately controlled. In order to achieve this, the slit pattern needs to be formed with high accuracy. In the present invention, the slit pattern is formed with high accuracy by the following forming method, whereby the transport speed by the transport belt 56 can be accurately controlled. Therefore, a method for forming a slit pattern in the present embodiment will be described below.

  In the present embodiment, in contrast to this forming method, as shown in FIG. 3 (FIG. 3B shows a partially broken state), a cylindrical shape whose outer diameter is equal to or larger than the inner diameter of the conveyor belt 56 is used. A jig body 110, a plurality of slit forming portions 120 regularly arranged along an outer peripheral surface that comes into contact with an inner peripheral surface of the conveyor belt 56 when the conveyor belt 56 is fitted into the jig body 110, and a jig A heating unit (heater) 130 that is disposed so as to surround the main body 110 and that heats the entire conveyor belt 56 fitted in the jig main body 110 from the outside, a region in which the outer diameter is smaller than the inner diameter of the conveyor belt 56 A cylindrical taper portion 140 formed by forming a taper continuously changing from the upper end of the jig main body 110 to the region having the same outer diameter as the jig main body 110 at the upper end (the upper end in FIG. 3). Tubular jig 100 Used.

Among these, the outer diameter (A + d) of the jig body 110 is larger than the inner diameter (A) of the transport belt 56 in a state where the transport unit 50 is not configured, but the transport unit 56 is configured by the transport belt 56. The inner diameter (A + d) of the conveyor belt 56 in the state is configured to coincide. The slit forming unit 120 includes a magnetizing unit 122 (gray portion in FIG. 3B) that is a magnet that can magnetize a magnetic material with a positive electrode and a magnetizing unit 124 that is a magnet that can be magnetized with a negative electrode (FIG. 3B). )) At regular intervals along the outer peripheral surface in contact with the inner peripheral surface of the conveyor belt 56 (in this embodiment, 1/90 inch; 90 inches or more), and the surface thereof is arranged so as to be integrated with the outer peripheral surface of the jig body 110. Further, the outer diameter (Ad ′) of the upper end of the tapered portion 140 is smaller than the inner diameter (A) of the transport belt 56 in a state where the transport unit 50 is not configured.
(1) First, in the conveyance belt 56 that does not constitute the conveyance unit 50, an area on the inner peripheral surface that passes through a region that can be detected by the detector 59 in a state where the conveyance unit 50 is configured is subjected to a magnetic field from the outside. It is assumed that the magnetized portion 56a is magnetized (see FIG. 4A). Here, the magnetized portion 56 a is formed by applying a magnetic material to a corresponding region (region on one end side in the width direction) of the transport belt 56.
(2) Next, the conveyor belt 56 on which the magnetized portion 56a is formed is placed on the tapered portion 140 of the cylindrical jig 100 (see FIG. 4B). Here, since the lower end of the taper portion 140 has the same diameter as the outer diameter of the jig main body 110, the conveyance belt 56 is caught by the taper portion 140 at this stage.
(3) Next, the conveyor belt 56 placed on the tapered portion 140 is heated by the heating unit 130 (see FIG. 4C). Here, the conveying belt 56 is heated at a temperature at which the inner diameter of the conveyor belt 56 can be made equal to the outer diameter of the jig body 110. The heating by the heating unit 130 may be started before the conveyor belt 56 is put on the tapered portion 140. (4) Next, the conveyor belt 56 that is sufficiently heated and whose inner diameter is about the outer diameter of the jig body 110 is fitted into the jig body 110 (see FIG. 4D).
(5) Then, after the conveyor belt 56 is fitted into the jig body 110, each of the slit forming portions 120 in the cylindrical jig 100 magnetizes the magnetized portion 56a in the conveyor belt 56 to the positive electrode and the negative electrode, respectively. A magnetic slit pattern 56 b is formed on the inner peripheral surface of the conveyor belt 56. Since the slit forming portions 120 are arranged at regular intervals along the outer peripheral surface of the jig body 110, slit patterns are thereby formed at regular intervals.
4). Effect In the above-described “3. Method for forming slit pattern in transport belt 56”, transport is performed by each of a plurality of slit forming portions 120 regularly arranged along the outer peripheral surface of jig body 110 in cylindrical jig 100. Although a slit pattern is formed on the belt 56, it is not necessary to change or adjust the position of the conveyor belt 56 fitted in the jig body 110 when forming the slit pattern in this way. Therefore, unlike the method in which the slits are formed in order over the entire circumference of the conveyor belt 56, errors are not accumulated from the position where the slits are first formed, and the first slit and the last slit are formed. There is no big deviation in the positional relationship with the slit. In addition, unlike a method in which a pattern member formed with a slit pattern is attached to the conveyor belt, a slit pattern is formed later on the inner peripheral surface of the conveyor belt. There is no possibility of being shifted as in the slits at both ends of the pattern.

  As described above, according to the slit pattern forming method described above, a regular slit pattern can be formed on the transport belt 56 more accurately than in the past. More specifically, the magnetized portion 56a formed along the inner peripheral surface of the conveyor belt 56 is magnetized on the conveyor belt 56 at regular intervals by the slit forming unit 120, Thus, a magnetic slit pattern can be formed.

  And if it is the conveyance unit 50 comprised using the conveyance belt 56 in which the slit pattern was formed by such a method, a conveyance amount can be monitored accurately according to a regular slit pattern. This becomes more prominent because the slit pattern can be formed with high accuracy on the inner peripheral surface of the conveyor belt 56 as the slit forming portions 120 of the cylindrical jig 100 are arranged with higher accuracy.

  Further, the jig body 110 in the cylindrical jig 100 has the same outer diameter as the inner diameter (A + d) of the conveyance belt 56 in a state where the conveyance unit 56 is constituted by the conveyance belt 56, so that the actual conveyance is performed. A slit pattern may be formed in accordance with the state in which the unit 50 is configured. Therefore, even if the conveyance unit 56 is configured by the conveyance belt 56 actually formed with the slit pattern and the inner diameter of the conveyance belt 56 is increased by the tension at that time, the slit pattern is formed in this state. It is possible to prevent the intervals between the slits from becoming non-uniform due to such a change in the inner diameter.

  Further, when the transport belt 56 is fitted into the jig main body 110 of the cylindrical jig 100, the entire outer peripheral surface of the transport belt 56 is heated by the heating unit 130 to expand the transport belt 56. Therefore, the conveyor belt 56 is easily expanded uniformly over the entire circumference, and thus the conveyor belt 56 can be uniformly extended along the outer circumference of the jig body 110. Therefore, the extension of the conveyor belt 56 when fitted into the jig body 110 is likely to be uniform over the entire circumference, and thus the gap between the slits is displaced in the slit pattern formed by the slit forming portion 120. Can be prevented.

  Moreover, in the cylindrical jig 100, since the taper part 140 is formed in the upper part of the jig main body 110, the operation | work at the time of fitting the conveyance belt 56 in the jig main body 110 can be made easy. That is, in such a configuration, when the conveying belt 56 is fitted into the jig body 110, first, the tapered belt 140 is fitted into the tapered portion 140. The tapered portion 140 has an outer diameter at one end that is the inner diameter of the conveying belt 56. Therefore, the conveyance belt 56 can be easily fitted. Then, by gradually extending the conveying belt 56 from this state and shifting the conveying belt 56 toward the jig main body 110, the fitting into the jig main body 110 can be easily realized. .

Further, in the printer 1 described above, the conveyance unit 50 can accurately monitor the conveyance amount according to the slit pattern formed on the conveyance belt 56 with high accuracy, so that the deviation of the conveyance amount by the conveyance unit 50 is reduced. By doing so, it is possible to reduce the deviation of each pixel constituting the image formed on the recording paper p, and as a result, it is possible to improve the quality of the image formed on the recording paper p.
5. The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various forms can be taken as long as they belong to the technical scope of the present invention. Nor.

  For example, in the above embodiment, the configuration in which the transport unit of the present invention is applied as the transport unit 50 that transports the recording paper p is illustrated. However, the configuration of the present invention is, for example, a printer that transfers an electrostatic latent image formed on the photosensitive drum 42 to a recording medium through an intermediate transfer unit including an intermediate transfer belt after the electrostatic latent image is visualized with a developer. Of these, the transport unit of the present invention can be applied as an intermediate transfer unit. Also, among the printers that transfer the electrostatic latent image formed on the photosensitive unit formed of the photosensitive belt to a recording medium after being visualized with a developer, the transport unit of the present invention is applied as the photosensitive unit. You can also. That is, in these embodiments, it is configured as a transport unit that transports the visualized image (developer image) visualized by the developer by the belt.

  In the above-described embodiment, after the procedure (2) in “3. Method for forming slit pattern in the conveyor belt 56”, the conveyor belt 56 is heated and expanded in the procedure (3). The case where it fits in the tool main body 110 was illustrated. However, after the procedure of (2), the conveyor belt 56 is extended along the outer diameter of the jig body 110 without being heated in the procedure of (3), and is configured to be fitted into the jig body 110. May be.

  Further, in the above-described embodiment, the magnetized portion 56 a is formed by applying a magnetic material to a corresponding region of the transport belt 56 in the procedure (1) in “3. Method for forming slit pattern on transport belt 56”. The case of forming was illustrated. However, as a method of forming the magnetized portion 56 a, for example, the entire conveyance belt 56 is formed of a magnetic material, or a tape (magnetic tape) made of a magnetic material is attached along the inner peripheral surface of the conveyance belt 56. It is also possible to adopt a method such as

In the method of attaching the magnetic tape in this way, conventionally, the member on which the slit pattern is printed has to be attached to the transport belt while applying a certain amount of tension. Therefore, the slit pattern is formed together with the member by the tension at this time. In some cases, the slit pattern is not properly formed. However, in the above-described “3. Method of forming slit pattern in transport belt 56”, when a magnetic tape is applied,
Even if the magnetic tape is stretched in the step of applying the magnetic tape, the slit pattern (magnetic pattern) is formed after the magnetic tape is attached to the transport belt, so that the slit pattern becomes extended. In this way, the slit pattern can be formed with high accuracy.

  In addition, in the method of attaching the magnetic tape, both ends of the magnetic tape are processed so that an area where the magnetic tape is not attached does not exist in parallel with the width direction of the transport belt 56. It is desirable to keep it. As described above, if a region to which the magnetic tape is not attached exists in parallel with the width direction of the transport belt 56, the region parallel to the width direction should originally be magnetized to the positive electrode or the negative electrode. Nevertheless, it is not magnetized and the detection accuracy as an encoder may be reduced.

  As a specific example, as shown in FIG. 5 (a), it is conceivable that both ends of the magnetic tape 56b are cut obliquely from the opposite side in the width direction. If the magnetic tape 56 b is pasted so that the portions are parallel to each other, an area where the magnetic tape 56 b is not pasted does not exist in parallel with the width direction of the transport belt 56. Therefore, when the magnetic tape 56b is magnetized by the cylindrical jig 100, as shown in FIG. 5 (b), it is not magnetized although the region parallel to the width direction should be magnetized. Therefore, there is no possibility that the detection accuracy as an encoder is lowered.

  Further, in the above “3. Method for forming slit pattern on conveyor belt 56”, the configuration in which the slit pattern formed on conveyor belt 56 is magnetic slit pattern 56b is exemplified. However, as the slit pattern formed on the conveyance belt 56, in addition to the magnetic slit pattern, for example, a physical pattern formed by forming a physical slit on the conveyance belt, along the length direction of the conveyance belt. An optical (visual) pattern formed by forming a striped pattern (by printing or coloring) can also be used.

  In the case of the former (physical slit pattern), a physical slit can be formed as a slit forming portion 120 in the cylindrical jig 100 through the conveyance belt 56 (a constant region in the width direction). What is necessary is just to set it as the structure which has arrange | positioned the penetration part at regular intervals along the outer peripheral surface of the jig | tool main body 110 which contacts the inner peripheral surface of the conveyance belt 56. FIG. With this configuration, slits that are penetrated at regular intervals by the slit forming portions 120 can be formed in the transport belt 56 as a physical slit pattern.

  In the latter case (optical slit pattern), a line (a line along the direction intersecting the length direction) is formed (colored or colored) on the conveyor belt 56 as the slit forming portion 120 in the cylindrical jig 100. The printable line forming portions may be arranged at regular intervals along the outer peripheral surface contacting the inner peripheral surface of the transport belt 56. If it is such a method, the striped pattern formed in the conveyance belt 56 at regular intervals by each slit formation part 120 can be formed as an optical slit pattern.

  Further, in the above “3. Method for forming slit pattern on conveyor belt 56”, when the conveyor belt 56 is fitted into the jig main body 110, the magnetized portions 122 and 124, which are the slit forming section 120, are used in the conveyor belt 56. A case where the magnetized portion 56a is magnetized to form a magnetic slit pattern is illustrated. However, the magnetizing parts 122 and 124 in the slit forming part 120 may be constituted by electromagnets that can be switched ON / OFF by a switching element so that the magnetized part 56a can be magnetized at an arbitrary timing. . In this case, for example, when the conveyance belt 56 is fitted into the jig main body 110, the heating by the heating unit 130 is stopped, and then the temperature of the conveyance belt 56 is lowered to some extent, for example, the slit forming unit 120. It is also possible to form the slit pattern at the timing when the temperature is lowered to a temperature suitable for the formation of the slit pattern.

  Moreover, in the said embodiment, the cylindrical jig | tool 100 illustrated what was arrange | positioned so that the heating part 130 might surround the jig | tool main body 110. FIG. However, the heating unit 130 may be configured such that the outer peripheral surface of the jig body 110 functions as a heating unit so that the inner peripheral surface side of the conveyor belt is heated as a whole.

The figure which shows the internal structure of an image forming apparatus Block diagram showing control system of image forming apparatus Diagram showing cylindrical jig The figure which shows the formation procedure of the slit pattern to the conveyance belt The figure which shows the conveyance belt in another embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer, 12 ... Paper tray, 14 ... Feed roller, 16 ... Conveyance roller, 18 ... Guide member, 20 ... Image forming part, 32 ... Discharge tray, 34 ... Discharge roller, 40 ... Image forming unit, 42 ... Photosensitive drum, 44 ... charger, 46 ... scanner part, 48 ... developing part, 50 ... conveying unit, 52 ... driving roller, 54 ... driven roller, 56 ... conveying belt, 56a ... magnetized part, 56b ... slit pattern, 56b ... magnetic tape, 58 ... transfer roller, 59 ... detector, 60 ... fixing unit, 62 ... heating roller, 64 ... pressing roller, 78 ... driver, 80 ... motor, 82 ... motor, 84 ... motor, 86 ... motor, DESCRIPTION OF SYMBOLS 100 ... Cylindrical jig, 110 ... Jig body, 110 ... Cylindrical jig, 120 ... Slit formation part, 122 ... Magnetization part, 124 ... Magnetization part, 130 ... Heating part, 140 ... Tape Part.

Claims (9)

A slit pattern forming method for regularly forming a slit pattern that can be detected by an encoder on a conveyor belt that can be constituted by a roller,
After the conveying belt is fitted into a cylindrical jig whose outer diameter is equal to or larger than the inner diameter of the conveying belt, the conveying belt is regulated along an outer peripheral surface that contacts the inner peripheral surface of the conveying belt in the cylindrical jig. A slit pattern forming method characterized in that a slit pattern is formed on the conveyor belt by each of a plurality of slit forming portions arranged in a regular manner. The conveyor belt is formed by forming a magnetized portion that is magnetized by receiving a magnetic field from the outside along at least an inner peripheral surface that is in contact with an outer peripheral surface of the cylindrical jig,
The cylindrical jig, as the slit forming portion, has an outer peripheral surface that contacts a magnetized portion that can magnetize a magnetized portion of the transport belt with a positive electrode and a magnetized portion that can be magnetized with a negative electrode with the inner peripheral surface of the transport belt. Are arranged at regular intervals along the
After the transport belt is fitted into the cylindrical jig, the magnetized portion of the transport belt is magnetized at regular intervals on the positive electrode and the negative electrode by the slit forming portion in the cylindrical jig, The slit pattern forming method according to claim 1, wherein a magnetic slit pattern is formed on the conveyor belt. The outer diameter of the cylindrical jig is greater than the inner diameter of the conveyor belt in the normal state, and, in the Tsu same der the inner diameter of the conveyor belt while constituting a conveying unit by conveying belts,
The slit pattern forming method according to claim 1, wherein the conveyor belt is extended along an outer diameter of the cylindrical jig and fitted into the cylindrical jig. The conveying belt is fitted to the cylindrical jig as being extended along the outer circumference of the cylindrical jig by heating and expanding the entire inner circumferential surface or outer circumferential surface of the conveying belt. The slit pattern forming method according to claim 1, wherein the slit pattern is formed. A cylindrical jig used to regularly form a slit pattern detectable by an encoder on a conveyor belt that can be configured by a roller over a conveyor unit,
A cylindrical jig body whose outer diameter is equal to or larger than the inner diameter of the conveyor belt;
It is regularly arranged along the outer peripheral surface of the jig body that contacts the inner peripheral surface of the conveyor belt when the conveyor belt is fitted into the jig body, and forms a slit pattern on the conveyor belt. And a plurality of slit forming portions. As the slit forming portion, a magnetized portion capable of magnetizing the magnetized portion of the transport belt with a positive electrode and a magnetized portion capable of being magnetized with a negative electrode are regularly spaced along the outer peripheral surface contacting the inner peripheral surface of the transport belt. Arranged in the
After the conveyor belt is fitted into the cylindrical jig, the slit forming portion is formed along the inner peripheral surface of the conveyor belt that contacts at least the outer peripheral surface of the cylindrical jig, and from the outside. A magnetized portion that is magnetized by receiving a magnetic field is magnetized at regular intervals on each of the positive electrode and the negative electrode, thereby forming a magnetic slit pattern on the transport belt. Item 6. The cylindrical jig according to Item 5. The outer diameter of the jig body is larger than the inner diameter of the conveyor belt in a normal state and is the same as the inner diameter of the conveyor belt in a state where the conveyor unit is configured by the conveyor belt. The cylindrical jig according to claim 5 or 6. 6. A heating section capable of heating and expanding the entire inner peripheral surface or outer peripheral surface of the conveyor belt with the conveyor belt fitted into the cylindrical jig. The cylindrical jig according to claim 6. Provided on the end side of the jig body is a cylindrical taper that continuously changes from a region where the outer diameter is smaller than the inner diameter of the conveyor belt to a region that is the same as the outer diameter of the jig body. The cylindrical jig according to claim 7 or 8, wherein the cylindrical jig is provided.

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