JP2004078173A - Image forming apparatus and full color image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which controls image forming operations with a high precision without being affected by the connection traces of a connection part of a transfer belt. <P>SOLUTION: The image forming apparatus is provided with: pattern detection sensors 15a and 15b which detect color matching patterns 18a and 18b formed on a transfer belt 17 and output pattern detection signals; a connection trace detection sensor 16 which is arranged together with pattern detection sensors 15a and 15b on a line on one axis D orthogonal to the advance direction of the transfer belt 7 and which detects connection traces 17 formed on a transfer belt 7 to output a connection trace detection signal and; a memory for storing the pattern detection signals and the connection trace detection signals therein; a pattern detection signal erasing part which erases the pattern detection signals in the case that the difference between a pattern detection signal and a connection trace detection signal is within a decision value; and a control part which controls image forming operations in accordance with the pattern detection signals left unerased by the pattern detection signal erasing part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and a full-color image forming method using the same.
[0002]
[Prior art]
2. Description of the Related Art In an image forming apparatus such as a light beam printer, a beam is scanned in a main scanning direction with respect to a rotating photosensitive member for each color component of an image based on image data transferred from an image reading unit or a host computer. An electrostatic latent image corresponding to each color component is formed on the body drum, and a toner image of each color component is developed and formed on the photoconductor drum by the toner of each color, and then these toner images of each color are used as a color matching pattern. Full-color color matching patterns Bk, Y, M, and C are created at intervals on the transfer belt, and a color image corresponding to the finally transferred image data is formed based on the full-color color matching patterns. Done.
When performing such an image forming operation, in order to form a high-quality color image faithfully corresponding to the transferred image data, a full-color color matching pattern is detected by a sensor, and based on the obtained detection data, It has been proposed to control image forming factors such as the amount of toner supplied and the amount of toner pumped to the electrostatic latent image on the photosensitive drum. It has also been proposed to accurately detect a resist pattern of each color for color misregistration correction control formed on a transfer belt, perform good color misregistration correction control, and obtain a good color image without color misregistration. (For example, Patent Document 1).
[0003]
[Patent Document 1]
JP 2000-314998 A
[0004]
[Problems to be solved by the invention]
By the way, in order to form a high-quality image, the transfer belt needs to set the circumferential dimension in the transport direction with high accuracy. Generally, a belt-shaped belt material is set so that the circumferential dimension becomes a predetermined value. In addition, both ends of the belt material are connected to each other.
For this reason, the transfer belt has a connection portion, and when the usage history time exceeds a predetermined time, the fixed connection state at the connection portion changes, and the transfer belt connected by the connection portion changes in circumferential length. Changes beyond the permissible variation range, it is necessary to replace it when the usage history time exceeds a predetermined time.
[0005]
Further, in the conventional image forming apparatus, when the color matching pattern is detected by the sensor, at the connection portion of the transfer belt, the sensor regards the connection mark pattern formed on the connection portion as a color matching pattern and incorrectly detects the connection mark pattern. To detect.
Since there is a connection mark pattern that is erroneously detected as a color matching pattern due to such erroneous detection, control in the case where the image forming operation is controlled based on a detection signal obtained by detecting the color matching pattern with the sensor. It becomes difficult to improve the accuracy.
In this case, if the transfer belt is formed in an integrally formed shape having no connection portion, it is possible to avoid erroneous detection of the connection trace pattern as a color matching pattern, but in order to form the transfer belt into an integrally formed structure, In addition, a complicated manufacturing process is required, which causes a problem in manufacturing cost.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus that controls an image forming operation with high accuracy without being affected by a connection mark of a connecting portion of a transfer belt.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is an image forming apparatus that forms a full-color image using a color matching pattern formed on a transfer belt,
At least one pattern detection sensor that detects the color matching pattern and outputs a pattern detection signal;
A connection mark that is arranged in line with the pattern detection sensor on the same axis that is orthogonal to the transfer direction of the transfer belt and that detects a connection mark formed on the transfer belt and outputs a connection mark detection signal. A detection sensor;
A memory for storing a digital signal converted from the pattern detection signal and the connection mark detection signal,
When the difference between the pattern detection signal converted to the digital signal and the connection mark detection signal converted to the digital signal is within a determination value, a pattern detection signal erasing unit that erases the pattern detection signal,
A control unit for controlling an image forming operation in accordance with the pattern detection signal remaining without being erased by the pattern detection signal erasing unit.
[0008]
According to such a means, the pattern detection signal detected by the connection mark of the transfer belt is deleted and is not reflected in the control of the image forming operation, so that the signal is not affected by the connection mark of the connection portion of the transfer belt. The image forming operation is controlled with high accuracy.
[0009]
According to a second aspect of the present invention, there is provided a replacement notice mode setting device for notifying the image forming apparatus of the first aspect that the transfer belt in use is replaced with a new one.
[0010]
According to such a means, in addition to the operation of the first aspect of the present invention, if the replacement notice mode is set, the control unit gives a notice of the transfer belt replacement at an appropriate time. The accuracy of the forming operation is not reduced.
[0011]
According to a third aspect of the present invention, there is provided the image forming apparatus according to the first aspect, further comprising a notice time setting unit for setting a notice time and notifying that the used transfer belt is replaced with a new one. .
[0012]
According to such a means, in addition to the operation of the first aspect of the present invention, when the advance notice time for exchanging the transfer belt is set, the exchange of the transfer belt is announced at the set time. And the accuracy of the image forming operation is not degraded due to the aging of the transfer belt.
[0013]
The invention according to claim 4 uses a transfer belt having a connection portion,
Forming a color matching pattern on the transfer belt,
A pattern detection sensor detects the color matching pattern and outputs a pattern detection signal,
Provide a connection mark detection sensor and the pattern detection sensor on the same axis orthogonal to the transfer direction of the transfer belt,
The connection mark detection sensor detects the connection portion formed on the transfer belt and outputs a connection mark detection signal,
A digital signal converted from the pattern detection signal and the connection mark detection signal is stored in a memory,
When the difference between the pattern detection signal and the connection mark detection signal is within a judgment value, the pattern detection signal is erased.
[0014]
According to such a means, among the pattern detection signals, those detected at the connection portion of the transfer belt are deleted and are not reflected in the control of the image forming operation, so that the full-color image forming operation is controlled with high accuracy.
[0015]
According to a fifth aspect of the present invention, there is provided a full-color image forming method according to the fourth aspect,
It is characterized in that the setting of the notice mode is accepted and a notice is given to replace the used transfer belt with a new one.
[0016]
According to such means, a notice of replacement of the transfer belt is given at an appropriate time, so that the accuracy of the image forming operation is not deteriorated due to the aging of the transfer belt.
[0017]
According to a sixth aspect of the present invention, there is provided a full-color image forming method according to the fourth aspect,
An operation for setting a notice time is received, and when the notice time has elapsed, a notice is given to replace the transfer belt in use with a new one.
[0018]
According to such a means, the replacement of the transfer belt is notified at the set time, so that the transfer belt can be replaced accurately and the accuracy of the image forming operation does not decrease due to the aging of the transfer belt.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention will be described with reference to FIGS.
1 is a block diagram showing the configuration of the present embodiment, FIG. 2 is a perspective view showing the configuration of the transfer belt and the detection sensor unit of FIG. 1, and FIG. FIG. 4 is an explanatory view showing the principle of arrangement, and FIG. 4 is a flowchart showing a notice notification operation of transfer belt replacement according to the present embodiment.
[0020]
In this embodiment, as shown in FIG. 1, an image forming unit 20 for forming an image and a control unit 21 for controlling the operation of the image forming unit 20 are provided. A writing unit 1 to which image data F3 transferred from an image reading unit or a host computer is input is provided. Opposite to the writing unit 1, M (Magenta) color separation data of the image data F3 A photosensitive drum 3M on which an electrostatic latent image of image data is formed is provided.
[0021]
Similarly, facing the writing unit 1, the photosensitive drum 3C on which an electrostatic latent image of C image data is formed based on the C (Cyan) color separation data of the image data F3, and Y (Yellow) of the image data F3 A photosensitive drum 3Y on which an electrostatic latent image of Y image data is formed based on the color separation data, and a photosensitive drum on which an electrostatic latent image of BK image data is formed based on BK (Black) color separation data of the image data. A body drum 3BK is provided.
[0022]
Further, the electrostatic latent images formed on the photosensitive drums 3M, 3C, 3Y, and 3BK are respectively brought into close proximity to the photosensitive drums 3M, 3C, 3Y, and 3BK. , 2K, and 2BK for developing the BK images.
[0023]
Further, the image forming unit 20 is provided with a transfer belt 7 which is conveyed in a direction indicated by an arrow by driving rollers 6a and 6b and a guide roller 11 in a state of being in contact with the photosensitive drums 3M, 3C, 3Y and 3BK. M visible images, C visible images, Y visible images, and BK visible images developed on the photosensitive drums 3M, 3C, 3Y, and 3BK are respectively opposed to the photosensitive drums 3M, 3C, 3Y, and 3BK with the transfer belt 7 therebetween. Transfer units 5M, 5C, 5Y, and 5BK for sequentially transferring images to the transfer belt 7 are provided.
[0024]
Further, between the driving roller 6b and the guide roller 11, a detection sensor unit 12 for detecting a full-color color matching pattern formed on the transfer belt 7 and a connection mark 17 of a connection portion J of the transfer belt 7 is provided. .
[0025]
As shown in FIG. 2, the detection sensor units 12 are pattern detection sensors that are respectively disposed at positions separated from each other on an arrangement line D perpendicular to the transfer direction of the transfer belt 7 so as to be close to and opposed to the transfer belt 7. 15A, a pattern detection sensor 15b, and a connection mark detection sensor 16 disposed on the arrangement line D so as to face outside the image forming area of the color matching pattern of the transfer belt 7.
Further, a cleaning unit 10 is disposed between the guide roller 11 and the driving roller 6a so as to be in close proximity to the transfer belt 7 and to clean the transfer belt 7 after the completion of the image forming process.
[0026]
On the other hand, a control unit 21 is connected to an output terminal of the detection sensor unit 12. The control unit 21 is connected to the detection sensor unit 12, and performs image processing based on a detection signal of the detection sensor unit 12. A control operation unit 13 for calculating and outputting an adjustment signal for instructing adjustment control of the forming operation is provided. The control operation unit 13 is connected to a general control unit 14 for controlling the entire image forming operation. Is connected to a display 22 for displaying various information. The image forming control signal F <b> 2 is input from the general control unit 14 to the image forming unit 20.
[0027]
Further, in the present embodiment, when the transfer belt 7 having the connection portion is used in the control operation unit 13, the number of detection histories of the connection trace detection signal of the connection trace detection sensor 16 for determining the replacement of the transfer belt 7 is determined. And a message selection means for selecting whether or not to perform a replacement advance notification when the number of times of detection of the connection mark detection signal reaches the replacement determination value.
[0028]
The operation of the present embodiment having such a configuration will be described.
In the present embodiment, the image forming unit 20 performs the image forming operation by the image forming control signal F2 input from the general control unit 14 to the image forming unit 20, but the transfer belt 7 is driven by the driving rollers 6a and 6b. In the state where the photosensitive drums 3M, 3C, 3Y, and 3BK are rotated clockwise at the same peripheral speed as the transfer belt 7, the image is M image data is extracted and acquired from the data F3, and based on the M image data, the photosensitive drum is subjected to optical writing by an optical system including a laser, a polygon mirror, an f / θ lens, a reflection mirror, and the like of the writing unit 1, and the like. An electrostatic latent image of M image data (hereinafter referred to as M latent image) is formed on 3M.
[0029]
Further, when the M latent image passes the position of the developing unit 2M due to the rotation of the photosensitive drum 3M, the M latent image formed on the photosensitive drum 3M is developed by the M toner from the developing unit 2M, and the photosensitive drum 3M is developed. An M visible image is formed on 3M.
Then, in the process in which the M visible image formed on the photosensitive drum 3M passes through the position of the transfer roller 5M by the rotation of the photosensitive drum 3M, the M voltage of the photosensitive drum 3M is changed by the bias voltage applied to the transfer roller 5M. The visual image is transferred to the transfer belt 7.
[0030]
On the other hand, based on the C image data extracted and obtained from the image data F3, a predetermined time is shifted from the optical writing of the M latent image to the photosensitive drum 3M by the optical system to the photosensitive drum 3C. An electrostatic latent image of a C image (hereinafter, referred to as a C latent image) is formed, and then the C latent image formed on the photosensitive drum 3C is developed with C toner from the developing unit 2C, and the photosensitive drum 3C Is formed with a C-visible image. Then, in synchronization with the leading portion of the C visualized image reaching the position of the transfer roller 5C, the leading portion of the M visualized image transferred onto the transfer belt 7 reaches the position of the transfer roller 5C, and is transferred by the transfer roller 5C. The C visual image of the photosensitive drum 3C is successively superimposedly transferred onto the M visual image of No. 7 to sequentially form a color matching pattern of the M visual image and the C visual image on the transfer belt 7.
[0031]
Similarly, the electrostatic latent image of the Y image formed on the photosensitive drum 3Y (hereinafter referred to as the Y latent image) is developed by the optical system at a timing shifted by the Y toner from the developing unit 2Y, The Y visual image formed on the drum 3Y is superimposed and transferred by the transfer roller 5Y on the color matching pattern of the M visual image and the C visual image transferred to the transfer roller 5Y position, and the M visual image, the C visual image and The color matching pattern of the Y visual image is sequentially formed on the transfer belt 7.
[0032]
Then, at a timing shifted by the optical system, the electrostatic latent image of the BK image formed on the photosensitive drum 3BK (hereinafter referred to as BK latent image) is developed by the BK toner from the developing unit 2BK, and the photosensitive drum 3BK is developed. Is superimposed and transferred by the transfer roller 5BK onto the color matching pattern of the M, C, and Y visual images transferred to the transfer roller 5BK position, so that the M visual image is formed. , C, Y and BK images are successively formed on the transfer belt 7.
[0033]
In this manner, an image corresponding to the image data F3 is formed on the transfer belt 7 by a full-color color matching pattern based on the M visualization, the C visualization, the Y visualization, and the BK visualization. Although not shown, in the vicinity of the guide roller 11, the image is collectively transferred to a transfer sheet disposed in contact with the transfer belt 7, subjected to a fixing process, and an image corresponding to image data is formed on the transfer sheet to perform an image forming operation. Ends.
[0034]
In this embodiment, a full-color color matching pattern in which the M, C, Y, and BK images finally formed on the transfer belt 7 are transferred in the image forming operation process. The connection sensor 17 at the connection portion J of the transfer belt 7 is detected by the detection sensor unit 12.
[0035]
In this case, as shown in FIG. 2, the M, C, Y, and BK images are superimposed and transferred to form the full-color color matching patterns 18a and 18b. In the area on the transport direction side, a pattern detection sensor 15a and a pattern detection sensor 15b which are arranged separately from each other on an arrangement line D which is close to and opposed to the transfer belt 7 and is perpendicular to the transport direction of the transfer belt 7 Corresponding full-color color matching patterns 18a and 18b are detected for each unit time. Then, the connection mark 17 of the connection portion J of the transfer belt 7 is detected by the connection mark detection sensor 16 arranged on the arrangement line D so as to face outside the image forming area of the pattern of the transfer belt 7.
[0036]
The pattern detection signals from the pattern detection sensors 15a and 15b are input to the control operation unit 13, are sequentially A / D converted into digital signals by AD conversion means, and are sequentially stored in the memory of the control operation unit 13 as voltage values. In this case, the control operation unit 13 converts the detection signal into a voltage by AD conversion using the sawtooth signal and the reference clock (sampling clock).
[0037]
Then, as shown in FIG. 5, the first count value (start mark (mark at the top of FIG. 3)) of the reference clock until the voltage of the pattern detection signal reaches the reference signal level (corresponding to the average toner density). From the count), the voltage of the pattern detection signal exceeding the reference signal level decreases, and the second count value of the reference clock until the voltage reaches the reference signal level again is calculated. Next, the first count value is added to a half of the difference between the first count value and the second count value, and the obtained count value is stored in the memory of the control operation unit 13 as pattern position information. Stored sequentially.
[0038]
Also, the connection operation detection signal from the connection operation detection sensor 16 is subjected to the same AD conversion processing in the control operation unit 13 as that for the pattern detection signals of the pattern detection sensors 15a and 15b, and is obtained in a similar manner. The count value is stored in the memory of the control operation unit 13 as connection mark position information.
[0039]
Next, the count values corresponding to the positions of Bk, Y, M, and C detected by the pattern detection sensor 15a are Na1 to Nan, the count value corresponding to the positional information of the connection mark is Nc, and A is the proximity determination value. , The following calculation is performed.
[0040]
−A <Nax−Nc <A (x = 12... N) (1)
[0041]
Similarly, the count value corresponding to the pattern detection signal of the pattern detection sensor 15b stored in the memory of the control operation unit 13 is Nb1 to Nbn. Then, the count value corresponding to the connection mark detection signal of the connection mark detection sensor 16 stored in the memory of the control calculation unit 13 is set to Nc, and A is used as a determination value, and the following calculation is performed.
[0042]
−A <Nbx−Nc <A (x = 12... N) (2)
[0043]
As shown in FIG. 6, Nax and Nbx corresponding to the x value at which the expressions (1) and (2) are simultaneously satisfied are detection signals indicating that the pattern detection sensors 15a and 15b have detected the connection mark of the transfer belt 7. Is determined to be regarded as the pattern detection signal, and is deleted from the storage of the memory of the control operation unit 13. (If the simultaneously established position information is deleted, erroneous detection when one sensor detects dust or the like can be excluded.)
[0044]
In this manner, the pattern detection corresponding to the detection signal of the full-color color matching pattern from which the count value of the pattern detection signal obtained by reading the connection mark 17 of the connection portion J of the transfer belt 7 detected by the pattern detection sensors 15a and 15b is removed. The count value of the sensor 15a and the count value of the pattern detection sensor 15b are finally corrected and stored in the memory of the control operation unit 13.
[0045]
That is, when the difference between the digitally converted pattern signals Nax and Nbx and the digitally converted connection trace signal Nc is within the determination value ± A, the pattern detection signal It is erased by a pattern detection signal erasing unit (not shown).
[0046]
Next, the control operation unit 13 adjusts and controls the image forming operation based on the count value corresponding to the detection signal of the full-color color matching pattern that does not include the erroneous detection data remaining without being erased by the pattern detection signal erasing unit. The adjustment signal F1 is calculated, and the calculated adjustment signal F1 is output to the general control unit (control unit) 14.
[0047]
Then, the integrated control unit 14 creates an image forming control signal F2 for controlling the image forming operation of the image forming unit 20 based on the adjustment signal F1 from the control arithmetic unit 13, and generates the created image forming control signal F2. The image is input to the image forming unit 20, and the image forming unit 20 performs an image forming operation based on the image forming control signal F2.
[0048]
In this way, in the image forming unit 20, when the adjustment control is required, the toner supply amounts of the developing units 2M, 2C, 2Y, and 2BK, the bias voltage values applied to the transfer rollers 5M, 5C, 5Y, and 5BK Are properly adjusted based on the detection signals of the full-color color matching patterns of the pattern detection sensors 15a and 15b, and a high-quality image is always formed corresponding to the image data F3.
[0049]
On the other hand, in this embodiment, a notice of replacement of the transfer belt 7 is given. In this notice of replacement, the memory of the control operation unit 13 corresponds to the connection mark detection signal of the connection mark detection sensor 16 in step S1 of FIG. When Nc is stored as the count value and it is determined that the transfer belt 7 being used has a structure having a connection portion, the process proceeds to step S2.
[0050]
In step 2, it is determined whether or not the count value Nc of the connection mark detection signal has exceeded a predetermined determination set value. If it is determined that the count value Nc has exceeded the determination set value, the process proceeds to step S3. Then, it is determined whether or not the message selection is set in the control operation unit 13. If it is determined that the message selection is set, the process proceeds to step S <b> 4, based on the instruction of the control operation unit 13, The control unit 14 displays on the display 22 a message indicating that the transfer belt 7 needs to be replaced.
[0051]
As described above, if the user selects and sets the replacement notice of the transfer belt 7 in advance in the replacement notice mode setting unit provided in the control arithmetic unit 13 and sets the replacement determination value based on the conventional data, the transfer in use is performed. The history usage time of the belt 7 is determined based on the number of times of detection of the connection mark, and the display 22 indicates that the replacement is required. By the replacement, high-quality image formation is continued.
In this case, if the user does not select the transfer belt 7 notification notice, the transfer belt is replaced at the regular replacement time.
[0052]
As described above, according to the present embodiment, the control arithmetic unit 13 converts the pattern detection signals from the pattern detection sensors 15a and 15b into pulse signals of the count value corresponding to the reference level of the signal and the change state of the signal level, respectively. The A / D conversion is performed, and the connection trace detection signal from the connection trace detection sensor 16 is AD-converted to a pulse signal of a count value corresponding to a change state of the signal reference level and the signal level, and the AD conversion is performed on the pattern detection sensors 15a and 15b. The difference between the count value of the pulse signal and the count value of the pulse signal of the connection mark detection sensor 16 is calculated, and if both obtained differences are determined to be within the predetermined determination value range, the corresponding The pattern detection signal detected by the pattern detection sensors 15a and 15b detected the connection mark 17 at the connection portion of the transfer belt 7. It is deleted from the data as of.
[0053]
For this reason, the control operation unit 13 calculates and calculates the adjustment signal F1 for adjusting and controlling the image forming operation based on the count value corresponding to the detection signal of the full-color color matching pattern not including the erroneous detection data. The adjustment signal F1 is output to the general control unit 14. From the general control unit 14, an image forming control signal F2 for controlling an image forming operation is input to the image forming unit 20 based on the adjustment signal F1. Thus, a high quality image forming operation can always be performed.
[0054]
Further, according to the present embodiment, when the exchange notice of the transfer belt 7 is selected, if the count value Nc of the connection mark detection signal exceeds a preset value, the command of the control operation unit 13 is issued. A message indicating that the transfer belt 7 needs to be replaced is displayed on the display 22 by the integrated control unit 14 based on the above, so that high-quality image formation can be performed by replacing the transfer belt 7 that accurately corresponds to the driving state of the apparatus. It is possible to continue.
[0055]
The transfer belt 7 can be replaced by setting the time. That is, the notice time may be set to notify that the transfer belt 7 in use is replaced with a transfer belt such as a new one.
[0056]
It should be noted that the present invention is not limited to the above-described embodiment. In the example, a case in which two pattern detection sensors are provided has been described. Thus, it is possible to perform the adjustment control with higher accuracy.
[0057]
Further, in this example, the transfer belt in use is replaced with a new transfer belt. However, the present invention is not limited to this, and the transfer operation is not affected by the image forming operation and the color matching pattern detecting operation. The belt does not need to be new.
[0058]
【The invention's effect】
According to the first aspect of the present invention, among the pattern detection signals, those detected by the connection mark of the transfer belt are deleted and are not reflected in the control of the image forming operation. It is possible to provide an image forming apparatus that controls the image forming operation with high accuracy without receiving the image.
[0059]
According to the second aspect of the present invention, in addition to the effect obtained by the first aspect of the present invention, when the exchange notice mode is set, the control unit notifies the replacement of the transfer belt at an appropriate time. Thus, high-precision image formation can always be performed without lowering the accuracy of the image forming operation.
[0060]
According to the third aspect of the present invention, in addition to the effect obtained by the first aspect of the present invention, when the advance notice time for exchanging the transfer belt is set, the exchange of the transfer belt is announced at the set time, so that the transfer is accurately performed. The belt can be replaced, and the image forming operation can always be performed with high accuracy without lowering the accuracy of the image forming operation due to the aging of the transfer belt.
[0061]
According to the fourth aspect of the present invention, among the pattern detection signals, those detected at the connection portion of the transfer belt are deleted and are not reflected in the control of the image forming operation, so that the full-color image forming operation is controlled with high precision. A full-color image forming method can be provided.
[0062]
According to the fifth aspect of the present invention, in addition to the effect obtained by the fourth aspect of the present invention, a notice of replacement of the transfer belt is given at an appropriate time, so that the accuracy of the image forming operation is improved due to the aging of the transfer belt. , And a high-precision image can always be formed.
[0063]
According to the invention as set forth in claim 6, since the transfer belt replacement is notified at the set time, the transfer belt can be replaced accurately, and the image forming operation is not deteriorated due to the aging of the transfer belt. An image can be formed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a configuration of a transfer belt and a detection sensor unit of FIG. 1;
FIG. 3 is an explanatory diagram showing the principle of arrangement of color matching patterns and connection marks in the transfer belt of FIG.
FIG. 4 is a flowchart showing a notice operation of transfer belt replacement notice according to the embodiment;
FIG. 5 is a diagram illustrating a relationship between a voltage of a pattern detection signal and a reference signal level in a time series.
FIG. 6 is a diagram showing a digital signal of a pattern detection sensor and a digital signal of a connection mark detection sensor stored in a memory.
[Explanation of symbols]
1 Writing unit
2M, 2C, 2Y, 2BK developing unit
3M, 3C, 3Y, 3BK Photoconductor drum
5M, 5C, 5Y, 5BK Transfer roller
7 Transfer belt
13 Control operation unit
14 Comprehensive control unit (control unit)
15a, 15b pattern detection sensor
16 Connection mark detection sensor
17 Connection marks
18a, 18b color matching pattern
20 Image forming unit
21 Control unit
22 Display
J connection

Claims (6)

In an image forming apparatus that forms a full-color image using a color matching pattern formed on a transfer belt,
At least one pattern detection sensor that detects the color matching pattern and outputs a pattern detection signal;
A connection mark that is arranged in line with the pattern detection sensor on the same axis that is orthogonal to the transfer direction of the transfer belt and that detects a connection mark formed on the transfer belt and outputs a connection mark detection signal. A detection sensor;
A memory for storing a digital signal converted from the pattern detection signal and the connection mark detection signal,
When the difference between the pattern detection signal converted to the digital signal and the connection mark detection signal converted to the digital signal is within a determination value, a pattern detection signal erasing unit that erases the pattern detection signal,
A control unit for controlling an image forming operation in accordance with the pattern detection signal remaining without being erased by the pattern detection signal erasing unit. An image forming apparatus, comprising: a replacement notice mode setting device that notifies the image forming apparatus according to claim 1 that the transfer belt in use is replaced with a new one. 2. An image forming apparatus according to claim 1, further comprising a notice time setting section for setting a notice time and notifying that the used transfer belt is to be replaced with a new transfer belt. Using a transfer belt with a connection,
Forming a color matching pattern on the transfer belt,
A pattern detection sensor detects the color matching pattern and outputs a pattern detection signal,
Provide a connection mark detection sensor and the pattern detection sensor on the same axis orthogonal to the transfer direction of the transfer belt,
The connection mark detection sensor detects the connection portion formed on the transfer belt and outputs a connection mark detection signal,
A digital signal converted from the pattern detection signal and the connection mark detection signal is stored in a memory,
When the difference between the pattern detection signal and the connection mark detection signal is within a determination value, the pattern detection signal is deleted. For the full-color image forming method according to claim 4,
We accept setting of notice mode,
A method for forming a full-color image, comprising notifying that a transfer belt in use is replaced with a new one. For the full-color image forming method according to claim 4,
Accepts the setting operation of the notice time,
A full-color image forming method, wherein when a notice time has elapsed, a notice is given to replace a used transfer belt with a new one.

Images