JP2005092126A - Belt drive control device and belt drive control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method for highly precisely driving a transfer belt at a constant speed by using a dummy signal in the joint section of the transfer belt. <P>SOLUTION: This device is provided with a transfer belt joint recognition pattern and a joint recognition sensor. Thus the joint of the transfer belt is surely recognized without being erroneously recognized as dust or the like deposited on the surface of a scale, so that a feedback control means corrects and controls the moving speed of the transfer belt autonomously by using the dummy signal in the joint section, thereby driving the transfer belt highly precisely at a constant speed, and also making the joint section into a transfer execution section. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a belt drive control device and a belt drive control method for a color copying machine, a color printer, a laser beam printer and the like provided with an intermediate transfer belt or a direct transfer belt.

  2. Description of the Related Art Conventionally, there is a method called surface detection drive control for the purpose of conveying a used intermediate transfer belt or direct transfer belt with high accuracy in a tandem type printing mechanism of an image forming apparatus employing an electrophotographic system. In this surface detection drive control, the transfer belt is driven at a constant speed by feeding back a signal obtained by reading a fine scale of equal intervals formed on the surface of the transfer belt with a photo sensor or the like to a drive motor for the transfer belt. It is a control method.

  For example, FIG. 8 is a schematic configuration diagram of a constant speed drive control device for an intermediate transfer belt in a conventional color copying machine to which this surface detection drive control is applied. Although not shown in FIG. 8, scales are provided on the intermediate transfer belt 1 at equal intervals. The scale is detected by the scale reading sensor 2, and the obtained scale detection signal is received by the feedback control means 3. Subsequently, the feedback control unit 3 determines whether or not the output value of the scale detection signal is an output value corresponding to the target speed of the intermediate transfer belt 1.

  As a result, when the output value of the scale detection signal is different from the output value corresponding to the target speed of the intermediate transfer belt 1, the feedback control means 3 is set so as to match the output value corresponding to the target speed. However, the intermediate transfer belt drive driver 4 controls the rotation speed of the intermediate transfer belt drive motor 5 by adjusting the rotation speed of the intermediate transfer belt drive motor 5. Thus, the intermediate transfer belt 1 is driven at a constant speed.

On the other hand, as a method of forming a scale provided on the transfer belt surface, a method of writing the scale directly on the belt material, a method of once forming the scale on a tape having an adhesive layer, and carefully attaching the tape to the transfer belt, Alternatively, there is a method of forming a scale by magnetic recording.
Japanese Patent Laid-Open No. 8-211163

  However, since the transfer belt is an endless belt, when the scale is formed on the transfer belt, any scale can be formed at the connecting portion (= joint) between the start point and the end point of the transfer belt by any of the scale forming methods described above. It is difficult to form scales at regular intervals just like the formation part. Therefore, the scale interval at the joint portion of the transfer belt has an error. This error is one of the factors that hinder the high accuracy of the constant speed drive of the transfer belt.

  In addition, as disclosed in Patent Document 1, there is a method in which a magnetic mark is formed as a scale, and this mark detection means is provided. Speed control is performed by knowing the shift time in a magnetic recording joint section by a pair of mark detectors (sensors). In this method, the joint portion of the transfer belt is used as a print driving start point (home position), and the joint section is not used as a transfer execution section.

  Therefore, in view of the above problems, the present invention performs high-precision control of the transfer belt by using a dummy signal for the section of the joint after recognizing the joint of the transfer belt by some method. An object of the present invention is to provide an image forming apparatus that achieves constant speed driving of a transfer belt.

  According to the first aspect of the present invention, there is provided a transfer belt used in an image transfer portion, a transfer belt driving roller for driving the transfer belt, and a transfer belt driving motor for rotating the transfer belt driving roller. A transfer belt driving motor driver for operating the transfer belt driving motor, a joint recognition pattern for recognizing a joint of the transfer belt provided at an arbitrary position of the transfer belt, and the joint recognition pattern. A joint recognition sensor for detection; a scale provided on the transfer belt; a scale reading sensor for detecting the scale; a joint detection signal obtained by detecting a joint by the joint recognition sensor; Acquired by a scale reading sensor detecting the scale A belt drive control device having feedback control means for receiving a kale detection signal and performing constant speed drive control of the transfer belt based on the content of the detection signal, wherein the feedback control means is configured to recognize the joint. The joint detection signal acquired by the sensor and the content of the scale detection signal acquired by the scale reading sensor are judged, and then the feedback control means outputs the feedback control means for the section of the joint portion. Using the dummy signal, the transfer belt driving driver is controlled, and then the transfer belt driving driver adjusts the rotation speed of the transfer belt driving motor and sets the rotation speed of the transfer belt driving roller. By adjusting the bell, the transfer belt is driven at a constant speed. Characterized in that the drive control unit.

  According to a second aspect of the present invention, the feedback control means is configured so that the joint is based on distance information between the joint recognition sensor and the scale reading sensor in the traveling direction of the transfer belt and speed information of the transfer belt. The joint passage time passing through the scale reading point on the transfer belt is predicted, and the feedback control means uses the detection signal determination means included in the feedback control means for the scale detection signal. It is determined that the output fluctuation of the scale detection signal within the passage time is a joint, or the output fluctuation of the scale detection signal outside the joint passage time is determined to be dust or dirt existing on the transfer belt. The belt drive control device according to claim 1.

  According to a third aspect of the present invention, the detection signal determining means provides a prescribed threshold having an appropriate output width for the scale reading detection signal, and the scale reading detection signal is output within the joint passage time. When the output fluctuates outside the specified threshold range, it is determined that the output fluctuation is a joint, or when the output of the scale reading detection signal fluctuates outside the prescribed threshold range outside the joint passage time. The belt drive control device according to claim 1, wherein the output fluctuation is determined not to be a joint but to dust or dirt existing on the transfer belt.

  In the invention according to claim 4, the scale reading sensor monitors a scale provided on the transfer belt, and the joint recognition sensor moves from the scale reading point in a direction opposite to the moving direction of the transfer belt. 4. The belt drive control device according to claim 1, wherein a joint recognition pattern of the transfer belt provided at an arbitrary arbitrary position corresponding to the joint of the transfer belt is monitored. 5. And

  According to a fifth aspect of the present invention, the scale, the scale detection sensor, the joint recognition pattern, and the joint recognition sensor are arranged at one end in the width direction of the transfer belt and on the same track. The belt drive control device according to any one of claims 1 to 4 is provided.

  According to a sixth aspect of the present invention, the scale and the joint recognition pattern are respectively divided and installed at one end in the width direction of the transfer belt, and the scale reading sensor is connected to the scale. The belt drive according to any one of claims 1 to 4, wherein the belt drive is installed on a track that moves with the transfer belt, and a joint recognition sensor is installed on the track on which the joint recognition pattern moves with the transfer belt. A control device is provided.

  According to a seventh aspect of the present invention, the scale and the joint recognition pattern are installed separately at both ends in the width direction of the transfer belt, and the scale reading sensor is connected to the scale along with the transfer belt. 5. The belt drive control device according to claim 1, wherein the belt recognition control sensor is installed on a moving track, and a joint recognition sensor is installed on a track on which the joint recognition pattern moves together with the transfer belt. It is characterized by that.

  According to an eighth aspect of the present invention, the scale is separately installed on the front side of the transfer belt, the joint recognition pattern is divided on the back side of the belt, and the scale reading sensor is installed on the scale. It is on a track that moves with the transfer belt, and is installed on the surface side of the transfer belt, and a joint recognition sensor is on the track on which the joint recognition pattern moves with the transfer belt, and The belt drive control device according to any one of claims 1 to 4, wherein the belt drive control device is installed on the back side.

  According to a ninth aspect of the present invention, the scale and the joint recognition pattern are formed so as to have different wavelength bands, and the scale reading sensor and the joint recognition pattern sensor for detecting these have sensing performance corresponding to each. The belt drive control device according to any one of claims 1 to 8 is provided.

  In a tenth aspect of the present invention, the detection method in which the scale reading sensor detects the scale and the detection method in which the joint recognition pattern sensor reads the joint recognition pattern are different detection methods, and the respective detection methods are , A method of using reflected light using a photo sensor, a method of detecting a transmitted light by making a hole in the transfer belt, a method of applying a magnetic film, an aluminum foil, etc. The belt drive control device according to any one of claims 1 to 9, wherein the belt drive control device is a detection method having the same effect as the detection method.

  The invention according to claim 11 is a transfer belt used for an image transfer portion, a transfer belt driving roller for driving the transfer belt, and a transfer belt driving motor for rotating the transfer belt driving roller. A transfer belt driving motor driver for operating the transfer belt driving motor, a joint recognition pattern for recognizing a joint of the transfer belt provided at an arbitrary position of the transfer belt, and the joint recognition pattern. A joint recognition sensor for detection; a scale provided on the transfer belt; a scale reading sensor for detecting the scale; a joint detection signal obtained by detecting a joint by the joint recognition sensor; The scale reading sensor is obtained by detecting the scale A belt drive control method including a scale detection signal and feedback control means for performing constant speed drive control of the transfer belt based on contents of the detection signals, wherein the feedback control means recognizes the joint A step of determining the contents of the joint detection signal acquired by the sensor and the scale detection signal acquired by the scale reading sensor; and the dummy output from the feedback control means to the section of the joint portion by the feedback control means. The step of controlling the transfer belt driving driver using the signal, and the transfer belt driving driver adjusts the rotation speed of the transfer belt driving motor and adjusts the rotation speed of the transfer belt driving roller. It has the process.

  According to a twelfth aspect of the present invention, the feedback control unit is configured such that the joint is based on distance information between the joint recognition sensor and the scale reading sensor in the traveling direction of the transfer belt and speed information of the transfer belt. A step of predicting a joint passage time passing through a scale reading point on the transfer belt; and the feedback control means uses the detection signal determination means included in the feedback control means for the scale detection signal. The output variation of the scale detection signal within the passage time is determined to be a joint, or the output variation of the scale detection signal outside the joint passage time is dust or dirt existing on the transfer belt. The belt drive control according to claim 11, further comprising a determining step. Characterized in that it was the law.

  According to a thirteenth aspect of the present invention, the detection signal determination means provides a specified threshold having an appropriate output width for the scale reading detection signal, and the scale reading detection signal is output within the joint passage time. The output of the scale reading detection signal fluctuates outside the specified threshold when the output fluctuates outside the specified threshold range, or when the output fluctuation is determined to be a joint, or outside the joint passage time. In such a case, the belt drive control method according to claim 11 or 12, further comprising a step of determining that the output fluctuation is not a joint but a dust or a dirt existing on the transfer belt.

  According to a fourteenth aspect of the present invention, the joint recognition sensor is implemented simultaneously with the step of monitoring the scale provided on the transfer belt and the step of monitoring the scale. 14. The method of monitoring a joint recognition pattern of the transfer belt provided at an arbitrary appropriate position corresponding to a joint of the transfer belt in a direction opposite to the moving direction of the transfer belt from the point. The belt drive control method according to any one of the above is employed.

  According to a fifteenth aspect of the present invention, the scale, the scale detection sensor, the joint recognition pattern, and the joint recognition sensor are arranged at one end in the width direction of the transfer belt and on the same track. The belt drive control method according to any one of claims 11 to 14 is provided.

  According to a sixteenth aspect of the present invention, the scale and the joint recognition pattern are respectively divided and installed at one end in the width direction of the transfer belt, and the scale reading sensor is connected to the scale. The belt drive according to any one of claims 11 to 14, wherein the belt drive is installed on a track that moves together with the transfer belt, and a joint recognition sensor is installed on the track where the joint recognition pattern moves together with the transfer belt. It is a control method.

  According to a seventeenth aspect of the present invention, the scale and the joint recognition pattern are separately provided at both ends in the width direction of the transfer belt, and the scale reading sensor is connected to the scale along with the transfer belt. The belt drive control method according to any one of claims 11 to 14, wherein the belt recognition sensor is installed on a moving track, and a joint recognition sensor is installed on a track on which the joint recognition pattern moves together with the transfer belt. It is characterized by that.

  The invention according to claim 18, wherein the scale is separately installed on the front surface side of the transfer belt, the joint recognition pattern is divided on the back surface side of the belt, and the scale reading sensor is installed on the scale. It is on a track that moves with the transfer belt, and is installed on the surface side of the transfer belt, and a joint recognition sensor is on the track on which the joint recognition pattern moves with the transfer belt, and The belt drive control method according to any one of claims 11 to 14 installed on the back side.

  According to a nineteenth aspect of the present invention, the scale and the joint recognition pattern are formed so as to have different wavelength bands, and the scale reading sensor and the joint recognition pattern sensor for detecting them have sensing performance corresponding to each. A belt drive control method according to any one of claims 11 to 18 is provided.

  According to a twenty-second aspect of the present invention, a detection method in which the scale reading sensor detects the scale and a detection method in which the joint recognition pattern sensor reads the joint recognition pattern are different detection methods, and the respective detection methods are , A method of using reflected light using a photo sensor, a method of detecting a transmitted light by making a hole in the transfer belt, a method of applying a magnetic film, an aluminum foil, etc. The belt driving control method according to any one of claims 11 to 19, wherein the belt driving control method according to any one of claims 11 to 19 is used.

  According to the present invention, by installing the transfer belt joint recognition sensor, it is possible to reliably recognize the joint of the transfer belt without misidentifying as dust adhering to the scale. Further, based on the result, when the scale reading sensor detects an output fluctuation different from the scale detection signal acquired from the section other than the joint portion of the transfer belt, the output fluctuation is a joint or dust. You can select and recognize things. Further, by using a dummy signal for the joint section, the moving speed of the transfer belt can be self-corrected and controlled, and the transfer belt can be driven at a constant speed with high accuracy. Further, by using the dummy signal, the joint section can be set as the transfer execution section.

  According to the present invention, by installing the joint recognition sensor, the joint of the transfer belt is reliably recognized, and on the basis of the result, the scale detection signal is obtained from the section other than the joint portion of the transfer belt. When different output fluctuations are detected, it is possible to provide an image forming apparatus that selectively recognizes that the output fluctuation is a joint or dust. In addition, by installing a feedback control means having a detection signal determination means, a dummy signal is used for the joint section, so that the transfer belt moving speed is self-corrected and controlled at a constant speed with high accuracy. In addition, it is possible to provide an image forming apparatus in which the joint section is a transfer execution section.

  The present invention is applied to an image forming apparatus such as a color copying machine, a color printer, and a facsimile, and particularly, an image forming apparatus including an intermediate transfer belt or a direct transfer belt. Embodiments of the present invention will be described below with reference to the accompanying drawings. In this embodiment, a color copying machine provided with an intermediate transfer belt will be described as an example.

  First, in order to facilitate understanding of one embodiment of the present invention, among the all image forming steps in the color copying machine of one embodiment of the present invention, in particular, the contents of the steps that proceed by driving the intermediate transfer belt will be briefly described. To do. As shown in FIG. 1, an image forming section provided with a number of developing units (yellow developing unit 7 a, magenta developing unit 7 b, cyan developing unit 7 c, black developing unit 7 d) corresponding to the number of colors on the intermediate transfer belt 1. Is provided. In the previous step, electrostatic latent images corresponding to the respective colors are formed on a photosensitive drum not shown in FIG. 1 in advance, and the electrostatic latent images corresponding to the respective colors as the intermediate transfer belt 1 travels are Each color developing device 7a, 7b, 7c, 7d causes toner to adhere and sequentially transfers it to the same position on the intermediate transfer belt 1 (primary transfer). By superimposing these color toner images, one color is obtained. Get an image.

  Subsequently, in the secondary transfer portion provided with the secondary transfer roller 9, the toner image formed by being superimposed on the intermediate transfer belt 1 is transferred onto the transfer paper 10 that is sent by a conveyance belt not shown in FIG. 1. Are secondarily transferred as a single color image. Therefore, in order to transfer a high-quality and high-quality color image to the transfer paper 10, it is necessary to drive and control the intermediate transfer belt 1 at a constant speed with high accuracy during the primary transfer and the secondary transfer.

  Next, the configuration and control operation of the device mechanism for constant speed drive control of the intermediate transfer belt 1 in one embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram of an apparatus mechanism for driving and controlling an intermediate transfer belt of a color copying machine according to an embodiment of the present invention at a constant speed. FIG. 2 is a partially enlarged perspective view of the vicinity of the intermediate transfer belt driving roller 6 in FIG.

  As shown in FIGS. 1 and 2, the apparatus mechanism for constant speed drive control of the intermediate transfer belt 1 mainly includes a belt-like scale 13, an intermediate transfer belt 1, a scale reading sensor 2, a feedback control means 3, and an intermediate transfer belt driving. The motor driver 4, the intermediate transfer belt driving motor 5, the intermediate transfer belt driving roller 6, the intermediate transfer belt rollers 8 a, 8 b and 8 c, the secondary transfer roller 9, and the joint recognition sensor 11 are configured.

  1 and 2, the scale 12 is formed so as to have a slit pattern for light absorption / reflection at a resolution of 150 dpi or higher, for example. Then, as shown in FIG. 2, the belt-like scale 13 is formed by being carefully attached to the end of the intermediate transfer belt 1 using an adhesive.

  Further, the intermediate transfer belt 1 is formed as an endless belt by joining both end portions of a belt-like belt having a certain thickness after being aligned so as not to be displaced in the width direction. Therefore, as shown in FIG. 2, the intermediate transfer belt 1 has a joint 14. The joint 14 generally has a length of 1 to 3 mm in the same direction as the traveling direction of the intermediate transfer belt 1, and its cross-sectional shape is different from other portions of the intermediate transfer belt 1. By joining both end portions of 1, an irregular shape having irregularities and the like is obtained.

  Therefore, for example, in the method of forming the band-like scale 13 by carefully attaching the belt-like scale 13 to the belt end portion using an adhesive as shown in FIG. 2, the scale 12 cannot be formed at the joint 14. Even if it can be formed, it is difficult to form the scales 12 at equal intervals. Note that it is difficult to form the scales 12 at equal intervals in other scale forming methods, for example, a method in which the scales 12 are directly written on the belt material, or a method in which the scales 12 are formed by magnetic recording. In this embodiment, as shown in FIG. 2, a case where the belt-like scale 13 provided with the scale 12 is not provided with an adhesive at the joint 14 of the intermediate transfer belt is taken as an example.

  For the purpose of reading the joint 14, the joint recognition sensor 11 for recognizing the joint recognition pattern 16 or the scale reading sensor 2 for detecting the scale 12 not shown in FIG. For example, a reflective photosensor or the like is used. As shown in FIG. 1, the joint recognition sensor 11 is installed at an appropriate upstream position in the direction opposite to the traveling direction of the intermediate transfer belt 1 with respect to the installation position of the scale reading sensor 2. FIG. 2 shows the relative positional relationship between the scale reading sensor 2, the scale 12 and the strip scale 13.

  Next, an outline of a procedure for controlling the constant speed drive of the intermediate transfer belt 1 of the color copying machine according to the embodiment of the present invention will be described. As shown in FIGS. 1 and 2, first, when the scale 12 attached to the belt-like scale 13 on the intermediate transfer belt 1 is detected by the scale reading sensor 2, the obtained scale detection signal is used for feedback control. Received by means 3. Next, the feedback control unit 3 determines whether or not the received scale detection signal is an output value corresponding to the target speed of the intermediate transfer belt 1.

  As a result, when the output value of the acquired scale detection signal is different from the output value corresponding to the target speed of the intermediate transfer belt 1, the feedback control unit 3 matches the output value corresponding to the target speed. Thus, a constant speed control of the intermediate transfer belt 1 is performed by adding a ± speed correction for the error.

  More specifically, the feedback control unit 3 controls the intermediate transfer belt drive driver 4, and the intermediate transfer belt drive driver 4 adjusts the rotational speed of the intermediate transfer belt drive motor 5 to thereby change the intermediate transfer belt drive driver 4. The rotation speed of the transfer belt driving roller 6 is adjusted so that the intermediate transfer belt 1 is driven at a constant speed. This control is performed for a section (a section other than the joint 14) in which the belt-like scale 13 of the intermediate transfer belt 1 is provided.

  As a method of determining whether the scale detection signal is an output value corresponding to the target speed of the intermediate transfer belt 1, as shown in FIG. A predetermined threshold having an appropriate output width is provided, and it is determined whether or not the output value of the scale reading detection signal has fluctuated outside the range of the predetermined threshold. The determination of the scale detection signal is performed by the feedback control means 3. When the output value of the scale detection signal fluctuates outside the specified threshold in the section where the belt-like scale 13 of the intermediate transfer belt 1 is provided (the section other than the joint 14), the scale signal included in the feedback control means 3 The judging means judges that the output fluctuation is not necessarily caused by a joint but caused by dust. Therefore, in a section other than the joint 14, the feedback control means 3 determines that the output fluctuation is caused by the joint, and erroneously performs constant speed drive control of the intermediate transfer belt 1 corresponding thereto. Absent.

  On the other hand, in this embodiment, as shown in FIG. 2, the joint 14 of the intermediate transfer belt 1 is a space of about 1 to 3 mm in which the belt-like scale 13 is not provided in the same direction as the traveling direction of the intermediate transfer belt 1. Since there is a gap, the scale detection signal is not detected in this joint section.

  In this case, when the conventional technique is applied, the problem is that the joint 14 cannot be accurately recognized. More specifically, the means for determining the output fluctuation of the scale detection signal by providing a prescribed threshold for the scale detection signal is that the output fluctuation of the scale detection signal is caused by dust (for example, toner on the scale) existing on the scale. It is not possible to stably determine whether it is caused by an adhesion or the like or a joint. For this reason, the joint 14 cannot be detected accurately, and as a result, it becomes difficult to perform constant speed drive control of the intermediate transfer belt 1 in the joint section.

  However, in this embodiment, as shown in FIGS. 1 and 2, a joint recognition sensor 11 is newly installed in addition to the scale reading sensor 2. Therefore, by using the joint recognition sensor 11, the joint 14 can be reliably recognized prior to the scale reading sensor 2. Based on the result, whether the output fluctuation of the scale detection signal acquired using the scale reading sensor 2 is caused by dust on the scale 12 or the joint 14 is surely determined. can do.

  Therefore, in this embodiment, since the joint 14 can be recognized reliably, the feedback control means 3 outputs a dummy signal similar to the normal scale detection signal detected from the scale 12 for this joint section. By applying this, constant speed drive control of the above-described intermediate transfer belt 1 can be performed. Therefore, constant speed drive control of the intermediate transfer belt 1 with higher accuracy than before is realized. Further, by using the dummy signal, the joint section can be set as the transfer execution section.

  Next, FIG. 3A is a diagram illustrating a state where dust (toner or the like) is attached on the belt-like scale 13. FIG. 3B shows a scale detection signal corresponding to FIG. As shown in FIGS. 3A and 3B, the scale detection signal corresponding to the scale 12 is a wavy signal indicated by a solid line and having the same peak value and the same half-value width at equal intervals. Further, the wavy signals 15 a ′ and b ′ having a peak value higher than that of the scale detection signal, which are indicated by dotted lines, are signals corresponding to the large and small dust 15 a and b attached on the belt-like scale 13. The signal corresponding to the joint recognition pattern is an AMP-like signal between ST shown in FIGS. 3 (a) and 3 (b).

  Next, the present embodiment will be described more specifically based on FIGS. 3 (c) and 3 (d). FIGS. 3C and 3D are diagrams for explaining the details of the control for recognizing the joint 14 and driving the intermediate transfer belt 1 at a constant speed by the joint recognition sensor 11 and the scale reading sensor 2 in this embodiment. FIG. FIG. 3C clearly shows the arrangement relationship between the joint recognition sensor 11 and the scale reading sensor 2.

  The joint recognition sensor 11 is installed upstream of the movement of the intermediate transfer belt 1 for the purpose of recognizing the passage of the joint 14. The scale reading sensor 2 is installed downstream of the intermediate transfer belt 1 for the purpose of controlling the joint section (no scale section).

  As shown in FIG. 3 (c), the joint recognition sensor 11 first reads the joint recognition pattern 16 provided on the belt upper surface of the joint 14 at the joint recognition point P to provide feedback control means. 3 recognizes the joint 14. Based on the result, the feedback control means 3 causes the joint 14 to pass through the scale reading point Q from the set length Lmm which is the distance between the joint recognition sensor 11 and the scale reading sensor 2 and the moving speed of the intermediate transfer belt 1. The joint passage start time, the joint passage end time, and the time required for the joint to pass (joint passage time) are predicted and converted.

Subsequently, when the scale reading sensor 2 captures the output fluctuation of the scale detection signal at the joint passage start time, the feedback control means 3 determines that the output fluctuation is caused by the joint 14; Subsequently, until the joint passage end time, the feedback control means 3 outputs the self-transmitting frequency shown in FIG. 3C using the dummy signal output by itself, and performs the synchronous operation of the intermediate transfer belt 1 based on this. . According to the control method described above, the correction operation in the joint section of the intermediate transfer belt 1 can be performed.
Note that the feedback control means 3 may output the self-transmitting frequency shown in FIG. 3D without using the dummy signal output by itself, and perform the synchronous operation of the intermediate transfer belt 1 based on this.

  As a modification of the example of one embodiment of the present invention, as shown in FIG. 4, a pattern 16 for recognizing the joint 14 and a joint recognition sensor 11 are provided separately from the scale 12 and the scale reading sensor 2, and the scale Installed in parallel near 12. In this embodiment, the pattern 16 and the joint recognition sensor 11 for recognizing the joint 14, the scale 12 and the scale reading sensor 2 are separately installed at arbitrary positions, so that reliable joint detection and control can be performed.

  As a modification of the example of one embodiment of the present invention, as shown in FIG. 5, a pattern 16 for recognizing the joint 14 and a joint recognition sensor 11 are provided separately from the scale 12 and the scale reading sensor 2, and the scale 12 on the opposite side of the transfer belt 1 in the width direction. In the present embodiment, the pattern 16 and the joint recognition sensor 11 for recognizing the joint 14, the scale 12 and the scale reading sensor 2 are separately installed at arbitrary positions, so that reliable joint detection and control can be performed.

  As a modification of the example of one embodiment of the present invention, as shown in FIG. 6, a pattern 16 for recognizing the joint 14 and a joint recognition sensor 11 are provided separately from the scale 12 and the scale reading sensor 2, and transfer is performed. Installed on the back side of the belt 1. In the present embodiment, the pattern 16 and the joint recognition sensor 11 for recognizing the joint 14, the scale 12 and the scale reading sensor 2 are separately installed at arbitrary positions, so that reliable joint detection and control can be performed. In addition, space saving can be realized.

  As a modification of the example of one embodiment of the present invention, it is assumed that the scale 12 and the joint recognition pattern 16 have different sensor sensitivity bands. For example, as shown in FIG. 7A, a joint recognition pattern 16 having a magenta wavelength band (sensitivity near 350 nm) as shown in FIG. 7B is installed on the joint 14 of the transfer belt. As a method for this, printing having a magenta color is performed on the joint 14 of the transfer belt, or a seal having a magenta color is pasted. The joint recognition sensor 11 uses a sensor capable of detecting the magenta wavelength band (sensitivity near 350 nm). By detecting the joint using this sensor, the joint can be reliably recognized.

  In addition, as a method of making the detection method of the scale and the joint different, a method of using reflected light using a photo sensor or the like, a method of detecting a transmitted light by opening a hole in the transfer belt, and applying a magnetic film A method of detecting the change in capacitance by attaching an aluminum foil or the like, or a detection method having the same effect as those can be used.

FIG. 2 is a schematic configuration diagram of an apparatus mechanism that controls the intermediate transfer belt of the color copying machine according to the embodiment of the present invention to drive at a constant speed. FIG. 3 is a partially enlarged perspective view of the vicinity of an intermediate transfer belt driving roller according to an embodiment of the present invention. (A) is a figure which shows the state which the dust has adhered on the strip | belt-shaped scale. (B) is a figure which shows the scale detection signal corresponding to (a). FIG. 6C is a diagram for explaining details of constant speed drive control of the intermediate transfer belt according to the embodiment of the present invention. (D) is a figure which shows the scale detection signal etc. corresponding to (c). It is a figure which shows the 1st modification of the Example of one Embodiment of this invention. It is a figure which shows the 2nd modification of the Example of one Embodiment of this invention. It is a figure which shows the 3rd modification of the Example of one Embodiment of this invention. (A) is a figure showing the 4th modification of an example of one embodiment of the present invention. (B) is a figure which shows the magenta wavelength band (sensitivity of 350 nm vicinity) which the joint recognition pattern has in the 4th modification of the Example of one Embodiment of this invention. FIG. 10 is a schematic configuration diagram of an apparatus mechanism that controls the intermediate transfer belt of a conventional color copying machine at a constant speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intermediate transfer belt 2 Scale reading sensor 3 Feedback control means 4 Intermediate transfer belt drive driver 5 Intermediate transfer belt drive motor 6 Intermediate transfer belt drive roller 7a Yellow developing unit 7b Magenta developing unit 7c Cyan developing unit 7d Black developing unit 8a Intermediate transfer belt roller 8b Intermediate transfer belt roller 8c Intermediate transfer belt roller 9 Secondary transfer roller 10 Transfer paper 11 Joint recognition sensor 12 Scale 13 Band scale 14 Joint 15a Dust (Large)
15b Garbage (small)
15a 'dust detection signal (large)
15b 'dust detection signal (small)
16 joint recognition pattern

Claims (20)

A transfer belt used in the image transfer section;
A transfer belt driving roller for driving the transfer belt;
A transfer belt drive motor for rotating the transfer belt drive roller;
A transfer belt driving motor driver for operating the transfer belt driving motor;
A joint recognition pattern for recognizing a joint of the transfer belt provided at an arbitrary position of the transfer belt;
A joint recognition sensor for detecting the joint recognition pattern;
A scale provided on the transfer belt;
A scale reading sensor for detecting the scale;
The joint recognition sensor receives a joint detection signal acquired by detecting a joint and the scale detection signal acquired by the scale reading sensor detecting the scale, and based on the contents of the detection signals, A belt drive control device having feedback control means for performing constant speed drive control of the transfer belt,
The feedback control means determines the content of the joint detection signal acquired by the joint recognition sensor and the scale detection signal acquired by the scale reading sensor;
Subsequently, the feedback control means controls the transfer belt driving driver using a dummy signal output by the feedback control means for the section of the joint portion,
Subsequently, the transfer belt driving driver adjusts the rotation speed of the transfer belt driving motor and adjusts the rotation speed of the transfer belt driving roller to drive the transfer belt at a constant speed. A belt drive control device. The feedback control means has a scale reading point on the transfer belt on the transfer belt based on distance information between the joint recognition sensor and the scale reading sensor in the running direction of the transfer belt and speed information of the transfer belt. Predict the joint transit time,
And the feedback control means uses the detection signal determination means of the feedback control means for the scale detection signal,
It is determined that the output fluctuation of the scale detection signal within the joint passage time is a joint,
2. The belt drive control device according to claim 1, wherein the output fluctuation of the scale detection signal outside the joint passage time is determined to be dust or dirt existing on the transfer belt. The detection signal determination means provides a specified threshold having an appropriate output width for the scale reading detection signal, and the output of the scale reading detection signal fluctuates outside the range of the specified threshold within the joint passage time. If so, it is determined that the output fluctuation is a joint,
Or, when the output of the scale reading detection signal fluctuates outside the range of the specified threshold outside the joint passage time, the output fluctuation is not a joint but is dust or dirt existing on the transfer belt. The belt drive control device according to claim 1 or 2, wherein the determination is made.   The scale reading sensor monitors a scale provided on the transfer belt, and the joint recognition sensor corresponds to a joint of the transfer belt from the scale reading point in a direction opposite to the moving direction of the transfer belt. 4. The belt drive control device according to claim 1, wherein a joint recognition pattern of the transfer belt provided at an appropriate arbitrary position is monitored. 5.   The scale, the scale detection sensor, the joint recognition pattern, and the joint recognition sensor are installed at one end portion in the width direction of the transfer belt and on the same track. Item 5. The belt drive control device according to any one of Items 1 to 4. The scale and the joint recognition pattern are respectively divided and installed on either one end of the transfer belt in the width direction,
And the scale reading sensor is installed on a track on which the scale moves together with the transfer belt,
5. The belt drive control device according to claim 1, wherein a joint recognition sensor is provided on a trajectory along which the joint recognition pattern moves together with the transfer belt. 6. The scale and the joint recognition pattern are respectively divided and installed at both ends in the width direction of the transfer belt,
And the scale reading sensor is installed on a track on which the scale moves together with the transfer belt,
5. The belt drive control device according to claim 1, wherein a joint recognition sensor is provided on a track along which the joint recognition pattern moves together with the transfer belt. 6. The scale on the surface side of the transfer belt,
The joint recognition pattern is divided and installed on the back side of the belt,
And the scale reading sensor is on a track on which the scale moves together with the transfer belt, and is installed on the surface side of the transfer belt,
5. The joint recognition sensor according to claim 1, wherein the joint recognition sensor is provided on a back surface side of the transfer belt on a track along which the joint recognition pattern moves together with the transfer belt. The belt drive control device described in 1. Forming the scale and the joint recognition pattern to have different wavelength bands;
The belt drive control device according to any one of claims 1 to 8, wherein the scale reading sensor and the joint recognition pattern sensor for detecting these also have sensing performance corresponding to each. A detection method in which the scale reading sensor detects the scale;
A detection method different from the detection method in which the joint recognition pattern sensor reads the joint recognition pattern,
And each detection method includes a method of using reflected light using a photo sensor, a method of detecting a transmitted light by making a hole in the transfer belt, a method of applying a magnetic film, an aluminum foil, etc. The belt drive control device according to any one of claims 1 to 9, wherein the belt drive control device is a method of attaching and detecting a change in capacitance, or a detection method having an effect similar to the method. A transfer belt used in an image transfer portion of an image forming apparatus;
A transfer belt driving roller for driving the transfer belt;
A transfer belt drive motor for rotating the transfer belt drive roller;
A transfer belt driving motor driver for operating the transfer belt driving motor;
A joint recognition pattern for recognizing a joint of the transfer belt provided at an arbitrary position of the transfer belt;
A joint recognition sensor for detecting the joint recognition pattern;
A scale provided on the transfer belt;
A scale reading sensor for detecting the scale;
The joint recognition sensor receives a joint detection signal acquired by detecting a joint and the scale detection signal acquired by the scale reading sensor detecting the scale, and based on the contents of the detection signals, A belt drive control method of a belt drive control device having feedback control means for performing constant speed drive control of the transfer belt,
The feedback control means determines the joint detection signal acquired by the joint recognition sensor and the content of the scale detection signal acquired by the scale reading sensor, and the feedback control means for the section of the joint portion, Using the dummy signal output by the feedback control means to control the transfer belt driving driver;
A belt driving control method comprising: a step of adjusting the rotational speed of the transfer belt driving motor, and the transfer belt driving driver adjusting the rotational speed of the transfer belt driving roller. The feedback control means is configured such that the joint is a scale reading point on the transfer belt based on distance information between the joint recognition sensor and the scale reading sensor in the running direction of the transfer belt and speed information of the transfer belt. Predicting the joint transit time passing through
The feedback control means determines, with respect to the scale detection signal, that the output fluctuation of the scale detection signal within the joint passage time is a joint using the detection signal determination means included in the feedback control means;
The belt drive control method according to claim 11, further comprising a step of determining that the output fluctuation of the scale detection signal outside the joint passage time is dust or dirt existing on the transfer belt. The detection signal determination means provides a specified threshold having an appropriate output width for the scale reading detection signal, and the output of the scale reading detection signal fluctuates outside the range of the specified threshold within the joint passage time. If so, the step of determining that the output fluctuation is a joint,
Or, when the output of the scale reading detection signal fluctuates outside the range of the specified threshold outside the joint passage time, the output fluctuation is not a joint but is dust or dirt existing on the transfer belt. 13. The belt drive control method according to claim 11 or 12, further comprising a determining step. The scale reading sensor monitoring a scale provided on the transfer belt;
The joint recognition sensor, which is performed simultaneously with the step of monitoring the scale, is at an arbitrary position corresponding to the joint of the transfer belt in the direction opposite to the moving direction of the transfer belt from the scale reading point. 14. The belt drive control method according to claim 11, further comprising a step of monitoring a joint recognition pattern of the transfer belt provided.   The scale, the scale detection sensor, the joint recognition pattern, and the joint recognition sensor are installed at one end portion in the width direction of the transfer belt and on the same track. Item 15. The belt drive control method according to any one of Items 11 to 14. The scale and the joint recognition pattern are respectively divided and installed on either one end of the transfer belt in the width direction,
And the scale reading sensor is installed on a track on which the scale moves together with the transfer belt,
The belt drive control method according to any one of claims 11 to 14, wherein a joint recognition sensor is installed on a track along which the joint recognition pattern moves together with the transfer belt. The scale and the joint recognition pattern are respectively divided and installed at both ends in the width direction of the transfer belt,
And the scale reading sensor is installed on a track on which the scale moves together with the transfer belt,
The belt drive control method according to any one of claims 11 to 14, wherein a joint recognition sensor is installed on a track along which the joint recognition pattern moves together with the transfer belt. The scale is installed on the front side of the transfer belt, and the joint recognition pattern is installed separately on the back side of the belt,
And, the scale reading sensor is on a track on which the scale moves together with the transfer belt, and is installed on the surface side of the transfer belt,
15. The joint recognition sensor according to claim 11, wherein the joint recognition sensor is installed on a back surface side of the transfer belt on a trajectory along which the joint recognition pattern moves together with the transfer belt. Belt drive control method. Forming the scale and the joint recognition pattern to have different wavelength bands;
The belt drive control method according to any one of claims 11 to 18, wherein the scale reading sensor and the joint recognition pattern sensor for detecting these also have sensing performance corresponding to each. A detection method in which the scale reading sensor detects the scale;
A detection method different from the detection method in which the joint recognition pattern sensor reads the joint recognition pattern,
And each detection method includes a method of using reflected light using a photo sensor, a method of detecting a transmitted light by making a hole in the transfer belt, a method of applying a magnetic film, an aluminum foil, etc. The belt drive control method according to any one of claims 11 to 19, wherein the belt drive control method is a method for detecting a change in capacitance by pasting or a detection method having an effect similar to the method.

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