JP3049035B1 - Method of detecting position of photosensitive belt in image forming apparatus and image forming apparatus using photosensitive belt - Google Patents

Abstract

An object of the present invention is to accurately and reliably detect a reference position for determining a writing timing and the like on a photoreceptor belt. SOLUTION: The photosensitive belt 4 extends in a sub-scanning direction,
In addition, a plurality of reference position detecting holes Ho (e.g., three rectangular holes formed at regular intervals in the main scanning direction and extending in the sub-scanning direction) formed at predetermined intervals in the main scanning direction are formed. A reference position on the photoreceptor belt is detected.
In this detection, LD is inserted in the reference position detection holes Ho of multiple slits.
The laser beams are emitted from the units 13a to 16a, and the photodetectors 13b to 16b receive and detect the light that has passed through the reference position detection holes Ho of the plurality of slits. By identifying the pattern in the main scanning direction with respect to the reference position detection holes Ho of the plurality of slits, and identifying the count value of the length or the number of lines in the sub-scanning direction, an accurate reference position on the photosensitive belt is determined. It is detected separately from minute damage holes caused by deterioration due to aging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an electrostatic latent image by irradiating a laser beam of an image signal and detecting a reference position on a photosensitive belt where development is performed. With respect to the method of detecting the position of the photoreceptor belt and an image forming apparatus using the photoreceptor belt, in particular, a reference position detection hole of a plurality of slits formed at predetermined intervals in the main scanning direction at equal intervals or non-equal intervals, The present invention relates to a method of detecting a position of a photoreceptor belt in an image forming apparatus for detecting a position of the photoreceptor belt by distinguishing the photoreceptor belt from a damage hole generated by deterioration due to aging of the photoreceptor belt, and an image forming apparatus using the photoreceptor belt.

[0002]

2. Description of the Related Art Conventionally, in a color image forming apparatus of this type, a laser beam of a color signal obtained by reading a document screen by an image reading device irradiates a photoreceptor belt charged by an eraser and charged by an eraser. Being
The electrostatic latent image is formed. Then, for example, a developing device for four-color toner (yellow, magenta, cyan, and black) disposed near the photoconductor belt supplies toner of each color for each rotation of the photoconductor belt to form an electrostatic latent image. After developing, the electrostatic development is transferred to a transfer roller or the like, and an image by full-color development is printed (transferred) on transfer paper. Thereafter, the full-color image is fixed on the transfer paper by a fixing roller or the like.

In such a color image forming apparatus using a photoreceptor belt, it is necessary to accurately detect the position of the photoreceptor belt for each rotation, that is, the position of the seam of the photoreceptor belt and the start position of image formation. is there. In particular, the start position and the end position in the electrostatic latent image formation on the photoreceptor belt by irradiating the eraser with the eraser, the charging by the charger, the irradiation of the laser beam of the color signal, and the developing device with each color toner, and In order to match the transfer position of the transfer paper, the position of the seam of the photoreceptor belt and the start position of image formation are accurately detected. In order to detect the position of the seam of the photosensitive belt and the start position (reference position) of image formation, a reference position is detected at a specific position of the photosensitive belt (TOPO).
(FROM, appropriately abbreviated as TOF).

Then, the laser beam light is scanned, and the laser beam light that has passed through the TOF hole when the photoreceptor belt rotates is detected by a photodetector, and each unit (eraser, charger,
A laser beam irradiation device, a four-color developing device, a transfer paper transporting device, and the like) perform a predetermined permutation operation (hereinafter, appropriately referred to as a sequence operation). If the position of the TOF hole in the photoreceptor belt is erroneously detected, for example, if a minute damaged hole caused by deterioration of the photoreceptor belt due to aging is detected as a reference position, each unit in the apparatus is detected. Cannot perform a normal sequence operation, and inconveniences such as formation of an electrostatic latent image across the seam of the photosensitive belt occur.

[0005] As a proposal relating to such a photosensitive belt position detection, a conventional example of a "speed control apparatus for a photosensitive belt for an electronic copying machine" disclosed in Japanese Patent Application Laid-Open No. Sho 60-42771 is known. In this conventional example, a mark added to the photoreceptor belt at regular intervals is detected, and the rotation speed of the photoreceptor belt is controlled. In the conventional example of the "color image forming apparatus" disclosed in Japanese Patent Application Laid-Open No. 9-54476, a plurality of marks (through holes) are formed at predetermined circumferential intervals along the widthwise edge of the intermediate transfer belt. The timing of writing image data when forming a latent image is controlled based on the output of a detector that detects a mark.

[0006]

As described above, in the above-described conventional example, a tiny damage hole caused by deterioration of the photosensitive belt due to aging is erroneously detected as a reference position, and writing to the photosensitive belt is in a normal position. However, there is a disadvantage that each unit in the apparatus cannot execute a normal sequence operation without performing the above operation.

Further, in the conventional example of Japanese Patent Application Laid-Open No. Sho 60-42771, a mark added to the photosensitive belt at regular intervals is detected to control the rotation speed of the photosensitive belt.
In addition to detecting the reference position, it is conceivable that accurate mark detection is difficult due to damage or dirt on the mark portion.

Further, in the conventional example of Japanese Patent Application Laid-Open No. 9-54476, although the timing of writing image data (formation of a latent image) can be controlled by detecting through holes in the intermediate transfer belt, minute damage to the photosensitive belt is caused. It cannot cope with prevention of erroneous detection of holes. Further, no consideration has been given to the formation of a through-hole that accurately distinguishes a damaged hole from a through-hole for detection, and a signal for a detection signal that accurately distinguishes the damaged hole from the through-hole for detection has not been considered. The processing is not described. Therefore, it can be considered that it is difficult to accurately detect the through hole for detection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and has a reference position detecting hole which can be accurately detected in a photoreceptor belt. Accurate detection signal processing that accurately distinguishes minute damage holes caused by deterioration due to aging of the belt becomes possible, and the reference position for determining the writing timing etc. on the photoreceptor belt is accurately and reliably It is an object of the present invention to provide a method for detecting the position of a photoreceptor belt in an image forming apparatus capable of detecting the image and an image forming apparatus using the photoreceptor belt.

[0010]

In order to achieve the above object, a method for detecting the position of a photoreceptor belt in an image forming apparatus according to the present invention comprises forming an electrostatic latent image by irradiating a laser beam light of an image signal. In the method of detecting the position of the photosensitive belt in the image forming apparatus for detecting the reference position on the photosensitive belt where development is performed, the photosensitive belt extends in the sub-scanning direction, and extends in the main scanning direction. Form a reference position detection hole of a plurality of slits at predetermined equal or non-equal intervals ,
Laser beam light is applied to the reference position detection holes of these multiple slits.
While irradiating while scanning
From the reference position detection holes of the plurality of slits
The beam light is detected and the detected laser beam light
The main scanning direction with respect to the reference position detection holes of multiple slits
Laser beam in the pattern identification and sub-scanning direction
Based on the count of the number of lines scanned by
By identifying the sub-position detection holes, the base on the photoreceptor belt can be identified.
The sub-position has been detected .

[0011] Image forming apparatus using the photoreceptor belt of the present invention, by irradiating a laser beam of the image signals to form an electrostatic latent image, and detects a reference position on the photosensitive belt which development is performed In an image forming apparatus using a photoreceptor belt, a photoreceptor belt extending in the sub-scanning direction, and having a plurality of reference position detection holes formed at predetermined intervals or non-equal intervals in the main scanning direction. Laser beam light is applied to the reference position detection holes of the plurality of slits formed in the photoreceptor belt .
Laser beam light irradiation elevation means for irradiating while canning
And the said passed through the reference position detection holes of the plurality of slits
Light receiving means for receiving the laser beam light from the irradiating means,
From the laser beam light received by the light receiving means,
Putter in the main scanning direction for the slit reference position detection hole
Identification and scanning of the laser beam in the sub-scanning direction.
Identification based on the number of counting lines.
Position detection for detecting a reference position on the photosensitive belt.
And a processing unit .

The irradiating means is a plurality of laser light emitting diode units for irradiating a photosensitive belt with laser beam light of a color signal obtained by reading a document image to perform writing, and the light receiving means is a laser light emitting diode unit. And a photodetector that receives the laser beam light from the light source.

The irradiating means is a laser light emitting diode dedicated to detection for irradiating the photosensitive belt with laser beam light, and the light receiving means is a photodetector for receiving the laser beam light from the laser light emitting diode. Further, the laser light emitting diode and the photodetector are arranged in the vicinity of each of a plurality of color developing devices.

By irradiating a laser beam light of an image signal,
A latent image is formed on the photosensitive belt on which development is performed.
Image forming apparatus using photoreceptor belt for detecting reference position
At the same time, extending in the sub-scanning direction and
Reference positions for multiple slits at regular or irregular intervals determined
A photoreceptor belt on which a detection hole is formed;
Laser beam is applied to the reference position detection holes of multiple slits
Laser beam irradiation for scanning and irradiating light
Means and passed through the reference position detection holes of the plurality of slits
Light receiving means for receiving laser beam light from the irradiating means
From the laser beam received by the light receiving means.
Recognize the pattern of the lit reference position detection hole in the main scanning direction
Main-scanning direction pattern recognition unit
From the output signal of the
Based on the count value of the number of scanning lines of the light beam
Reference position detection when the reference position detection hole is detected normally
It is constituted and a sub-scanning direction width count unit for outputting a signal.

The main scanning direction pattern recognition unit compares whether the pattern of the output signal from the light receiving means is the same as a predetermined set value corresponding to the reference position detection holes of the plurality of slits, and in this comparison, the same is determined. In the case of (1), a pattern comparison unit that outputs an output signal from the light receiving unit is provided.

The sub-scanning direction width counting section may include:
Pattern of output signal from light receiving means and the plurality of slits
Same as the preset value corresponding to the reference position detection hole of
Output from the main scanning direction pattern recognition unit when
Laser beam in the sub-scanning direction based on the
Counter that counts the number of scanning lines
And the value counted by this counter
Of laser beam light in the sub-scanning direction of the reference position detection hole
Comparison with the set value corresponding to the number of
Is greater than the set value, the reference position detection hole is
Comparator that outputs a reference position detection signal indicating that
This is a configuration including:

The laser beam emitted from the laser beam emitted to the reference position detecting holes of the plurality of slits is received and detected. Then, the pattern identification in the main scanning direction with respect to the reference position detection holes of the plurality of slits and the sub-scanning direction
The reference position on the photoreceptor belt is detected by the identification based on the count value of the scanning line number of the laser beam light in the above.

[0018] As a result, accurately distinguish between small damage holes caused by such degradation hole of special shape formed on the photosensitive belt (the exact detectable reference position detection hole) due to aging of the photosensitive belt become able to. That is, it is possible to accurately and reliably detect the reference position for determining the writing timing on the photosensitive belt.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method for detecting the position of a photosensitive belt in an image forming apparatus of the present invention and an image forming apparatus using the photosensitive belt will be described in detail with reference to the drawings. FIG. 1 is a side view showing an embodiment of a method for detecting the position of a photosensitive belt and an image forming apparatus using a photosensitive belt in the image forming apparatus of the present invention. 1, this image forming apparatus is, for example, a color image forming apparatus which performs color copying by developing and transferring an electrostatic latent image on a photosensitive belt with toner. A cassette 1, a transfer paper transport mechanism 2 for transporting transfer paper from the paper feed cassette 1, and rollers 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h
And a photoreceptor belt 4 having a reference position detection hole Ho shown in FIG.

In the color image forming apparatus, a photosensitive belt driving unit 5 for rotating the photosensitive belt 4 is provided.
And an eraser 6 for removing the residual toner on the photosensitive belt 4 and removing the charged charges, a charger 7 for uniformly charging the photosensitive belt 4, and a color signal (( For example, developing devices 8a, 8b, 8c, and 8d for developing toner (for example, four colors of yellow, magenta, cyan, and black) for each latent image for each of four colors (yellow, magenta, cyan, and black), and a photoconductor A transfer roller 9 for transferring the toner image on the belt 4 to the transfer paper, and a fixing roller 10 for pressing the transfer paper on which the toner image has been transferred and fixing the toner image by, for example, heat melting. It has.

Furthermore, this color image forming apparatus, a laser beam of a color signal conveying direction of the photosensitive belt 4 (the sub-scanning (Y) direction) width direction perpendicular to the (main scanning (X)
Direction), and irradiates (exposes) laser beam light to form an electrostatic latent image, and irradiates laser beam light to detect the reference position detection hole Ho shown in FIG.
To, located on each vicinity of the developing device 8a~8d laser emitting diode (LD) unit (optical writing unit) 13
a, 14a, 15a and 16a. Further, photodetectors 13b arranged corresponding to the laser light emitting diode units 13a to 16a and transmitting a photoelectric conversion signal (output signal) when receiving the laser beam light passing through the reference position detection hole Ho shown in FIG. 14b, 15
b, 16b.

Further , this color image forming apparatus uses a photoconductor bell based on output signals of the photodetectors 13b to 16b.
The reference position detection hole Ho formed in the gate 4 was normally detected.
Transfer the reference position detection processing unit 18 that outputs a reference position detection (TOF) signal, the above-described drive / control to each section, to generate a color development corresponding to the read document image, and this color development when And a drive / control unit 17 for outputting the transferred transfer sheet.

This arrangement is merely an example, and the arrangement position is changed depending on the configuration and functions of the apparatus.

FIG . 2 is a perspective view for explaining in detail the structure for detecting the position of the reference position detecting hole Ho formed in the photoreceptor belt 4, and FIG. FIG. 2 is a perspective view for explaining a detailed configuration. 2 and 3, the laser light emitting diode units 13a to 13a
The photoreceptor belt 4 is irradiated with a laser beam light for each color signal from 16a. The laser beam that has passed through the reference position detection hole Ho formed in the photoreceptor belt 4 is incident on the photodetectors 13b to 16b. As shown in FIG. 3, the laser light emitting diode units 13a to 16a scan the laser beam light for each color signal from the light emitting diode 20 with the polygon mirror 21 in the width direction (main scanning (X) direction) of the photosensitive belt 4. And irradiate through the objective lens 22.

FIG . 4 is a top view for explaining in detail the shape of the reference position detecting hole Ho formed in the photosensitive belt 4. In the reference position detection hole Ho of this example, three equally-spaced rectangular holes (slits, Ya / Xa) are formed. The three reference position detection holes Ho of the slits having an equal interval and a rectangular shape can be distinguished from the damaged holes generated in the photoreceptor belt 4 as artificial holes. That is, a base consisting of three equally spaced and rectangular holes
The quasi-position detection hole Ho means that it is unlikely to occur as a naturally damaged hole . Therefore, when a large number of damaged holes are likely to be generated in the photoreceptor belt 4, four or more equally-spaced rectangular holes or non-equally-spaced rectangular holes having a rule may be formed.

The liked this reference position detection hole Ho is to identify whether the predetermined pattern in the main scanning direction (Xa), further, the laser beam in the sub-scanning direction (Ya)
The reference position detection hole Ho is normally detected based on the count value of the number of the running lines (corresponding to three slits in this case). In other words, it is determined that the reference position detection hole Ho is not a damaged hole.

FIG . 5 shows the reference position detection processing unit 18 shown in FIG.
FIG. 3 is a block diagram showing a detailed electrical configuration of FIG. The reference position detection processing section 18 includes photo detectors 13b to 16b.
b from the output signal sent from the reference position detection hole H shown in FIG.
The main scanning direction pattern recognition unit 23 for recognizing the pattern in the main scanning direction (Xa) of o, and the number of scanning lines of the laser beam light in the sub-scanning direction (Ya) are counted to detect the reference position shown in FIG. A sub-scanning direction width counting unit 24 that outputs a reference position detection (TOF) signal when the hole Ho is normally detected.

The main scanning direction pattern recognition section 23 compares whether the pattern of the output signal from the photodetectors 13b to 16b is the same as a preset value A, and if the pattern is the same, outputs the signals from the photodetectors 13b to 16b. It has a pattern comparing section 23a for transmitting a signal.

The sub-scanning direction width counting unit 24 compares a count value of the output signal from the pattern comparing unit 23a of the main scanning direction pattern recognizing unit 23 with a set value B set in advance. And a comparator 24b that outputs a reference position detection (TOF) signal to the drive / control section 19, which indicates that the reference position detection hole Ho has been normally detected when the value is equal to or larger than the set value B.

Next, the operation of this embodiment will be described. In FIG. 1, a drive / control unit 19 executes a sequence of color image formation. First, a transfer paper transport mechanism 2 transports transfer paper from a paper feed cassette 1. At the same time, for example, the photoreceptor belt 4 is rotatably supported by the rollers 3a to 3h and is driven to rotate by the photoreceptor belt driving unit 5, and the eraser 6 removes the residual toner on the photoreceptor belt 4 and charges the photoreceptor belt 4. The charge is removed, and the charger 7 charges the photosensitive belt 4 uniformly. Laser beam light for each color signal (for example, four colors of yellow, magenta, cyan, and black) is supplied to the laser light emitting diode units 13a to 13a-1.
6a irradiates (exposes) the photosensitive belt 4 to form an electrostatic latent image.

The developing devices 8a to 8d perform toner development of four colors. The toner image on the photoreceptor belt 4 is transferred to the transfer roller 9, and the transfer paper conveyed by the transfer paper conveyance mechanism 2 is pressed against the fixing roller 10, and the toner image is melted by heat and fixed and sent out. I do. A predetermined drive and permutation operation (sequence operation) of these units is performed by the drive / control unit 1.
9 and is executed by control.

In this operation, the photosensitive belt 4 shown in FIG.
The laser beam light is scanned and irradiated in the width direction (main scanning (X) direction) from the laser light emitting diode units 13a to 16a to the reference position detection hole Ho formed in. At the same time, the photosensitive belt 4 is moved in the sub-scanning (Y) direction by the rotation of the photosensitive belt driving unit 5. With this move,
The laser beam light passing through the rectangular holes of the three slits of the reference position detection hole Ho is applied to the photodetectors 13b to 16b.
b. These photo detectors 13b to 16b
The received laser beam light is photoelectrically converted, and this output signal is input to the reference position detection processing unit 18. The reference position detection processing section 18 processes output signals from the photodetectors 13b to 16b and outputs a reference position detection (TOF) signal when the reference position detection hole Ho is normally detected.

Next, the operation of the reference position detection processing unit 18 will be described in detail. FIG. 6 is a diagram for explaining a reference position detection signal for the reference position detection hole Ho in the operation of the embodiment. When the laser beam light is emitted from the laser light emitting diode units 13a to 16a to the reference position detection holes Ho shown in FIG. 3, the output signals shown in FIG. 6 from the photo detectors 13b to 16b are generated by the main scanning and the sub scanning. Are input to the reference position detection processing unit 18. In the reference position detection processing section 18, the pattern comparison section 23a of the main scanning direction pattern recognition section 23 performs the scanning direction (X / main scanning direction) pattern for the rectangular holes of the three slits shown in FIG. The three slit patterns at intervals are compared to determine whether they are the same as the set value A set in advance.
The output signals from 3b to 16b are transmitted.

When the pattern is different from the set value A, the light received by the photodetectors 13b to 16b is, for example, a damaged hole caused by deterioration of the photoreceptor belt 4 due to aging, and a reference position detection (TOF) signal Is not output from the reference position detection processing unit 18.

When the pattern and the set value A are the same, the pattern comparing section 23a operates the photodetectors 13b to 13b.
6b is output to the counter 24a of the sub-scanning direction width counting unit 24. Counter 24a is rate in the sub-scanning (Y) direction shown in FIG. 4 with respect to the output signal of the photodetector 13b~16b from the pattern comparing section 23a
The number of scanning lines of the beam light is counted, and this count value is compared with a preset set value B by a comparator 2.
Compare with 4b . As a result of the comparison, when the count value is equal to or greater than the set value B, the drive / control unit 19 outputs a reference position detection (TOF) signal indicating that the reference position detection hole Ho has been normally detected.
Output to

When the comparison between the count value in the comparator 24b and the set value B is equal to or less than the set value B, the light received by the photodetectors 13b to 16b is, for example, a damaged hole generated by deterioration of the photosensitive belt 4 due to aging. The reference position detection (TOF) signal is not output from the reference position detection processing unit 18.

[0037] As a result, it is possible accurate detection signal processing to accurately distinguish between small damage holes caused by such degradation due to aging of the reference position detection hole Ho and the photoreceptor belt 4.

In this embodiment, the laser beam for detecting the reference position detection hole Ho is a laser beam of a color signal emitted from the laser light emitting diode units 13a to 16a, that is, an electrostatic latent image. Although it is shared with the laser beam light for forming, this may limit the free operation of the laser light emitting diode units 13a to 16a. In this case, it is preferable to use a light emitting diode dedicated to detection for irradiating laser beam light for detecting only the reference position detection hole Ho. That is, since the laser light emitting diode units 13a to 16a can operate independently, it is not necessary to restrict the operation.

[0039]

As is apparent from the above description, according to the method for detecting the position of the photosensitive belt in the image forming apparatus of the present invention and the image forming apparatus using the photosensitive belt, the photosensitive belt is moved in the sub-scanning direction. The reference position detection holes are formed to extend and have a plurality of slits at predetermined regular intervals or irregular intervals in the main scanning direction.

The laser beam irradiated on the reference position detection holes of the plurality of slits is detected by receiving the laser beam passed therethrough. Then, the pattern identification in the main scanning direction with respect to the reference position detection holes of the plurality of slits and the sub-scanning direction
The reference position on the photoreceptor belt is detected by identification based on the count value of the number of scanning lines of the laser beam light .

[0041] Consequently, to be able to accurately distinguish between small damage holes caused by such degradation being formed on the photoreceptor belt and accurately detectable reference position detection hole due to aging of the photosensitive belt, a photosensitive The reference position for determining the writing timing and the like on the body belt can be accurately and reliably detected.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of an embodiment of an image forming apparatus using a photosensitive belt and a method for detecting a position of a photosensitive belt in the image forming apparatus of the present invention.

FIG. 2 is a perspective view for describing in detail a configuration for detecting the position of a reference position detection hole formed in the photosensitive belt shown in FIG.

FIG. 3 is a perspective view for explaining a detailed configuration of a position detecting unit of the photosensitive belt in FIG. 1;

FIG. 4 is a top view for describing in detail a shape of a reference position detection hole formed in the photosensitive belt in FIG.

FIG. 5 is a block diagram illustrating a detailed electrical configuration of a reference position detection processing unit in FIG. 1;

FIG. 6 is a diagram for explaining a reference position detection signal in the operation of the embodiment.

[Explanation of symbols]

 Reference Signs List 4 photoreceptor belt 5 photoreceptor belt drive unit 6 eraser 7 charger 8a to 8d developing device 9 transfer roller 10 fixing roller 13a to 16a laser light emitting diode unit 13b to 16b photo detector 18 reference position detection processing unit 19 drive / control unit 20 light emitting diode Reference Signs List 21 polygon mirror 22 objective lens 23 main scanning direction pattern recognition unit 23a pattern comparison unit 24 sub-scanning direction width counting unit 24a counter 24b comparator Ho reference position detection hole

Continuation of the front page (56) References JP-A-6-143687 (JP, A) JP-A-4-152365 (JP, A) JP-A-4-181276 (JP, A) JP-A-61-20958 (JP) JP-A-5-119571 (JP, A) JP-A-6-40069 (JP, A) JP-A-59-113453 (JP, A) JP-A-59-111167 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 15/00 303 G03G 15/36 G03G 21/00 370-540 G03G 21/02-21/04 G03G 21/14 G03G 21/20 B41J 2/44

Claims (8)

(57) [Claims] 1. A photoreceptor belt position in an image forming apparatus for irradiating a laser beam light of an image signal to form an electrostatic latent image and detecting a reference position on the photoreceptor belt where development is performed. In the detection method, a reference position detection hole of a plurality of slits extending in the sub-scanning direction of the photoreceptor belt and having predetermined or equal intervals in the main scanning direction is formed, and the reference positions of the plurality of slits are detected. Laser beam light in the hole
While scanning, and this irradiation passes through the reference position detection holes of the plurality of slits.
The detected laser beam light is detected, and the detected laser beam
Main scanning direction pattern identification and sub scanning for position detection holes
Line scanned by laser beam in scanning direction
Identification of the reference position detection hole based on the
Detecting the reference position on the photoreceptor belt.
A method for detecting the position of a photoreceptor belt in an image forming apparatus. 2. An image forming apparatus using a photosensitive belt for irradiating a laser beam of an image signal to form an electrostatic latent image and detecting a reference position on the photosensitive belt on which development is performed, A photoreceptor belt that extends in the sub-scanning direction and has a plurality of slits formed at predetermined intervals in the main scanning direction that are equally spaced or non-equally spaced; Irradiate the position detection hole with laser beam light while scanning
Means for irradiating a laser beam, and the irradiation having passed through the reference position detection holes of the plurality of slits
Light receiving means for receiving the laser beam light from the means; and
Putter in the main scanning direction for the slit reference position detection hole
Liked in the identification and the sub-scanning direction of emission of the laser beam
Identification based on the number of counting lines.
Position detection for detecting a reference position on the photosensitive belt.
An image forming apparatus using the photoreceptor belt which is characterized in that it comprises a processing means. 3. A laser beam emitting diode unit for irradiating a photosensitive belt with laser beam light of a color signal obtained by reading a document image to perform writing, and wherein said light receiving means includes a laser light source. 3. The image forming apparatus using a photoreceptor belt according to claim 2 , wherein the photodetector is a photodetector that receives laser beam light from a light emitting diode unit. 4. An apparatus according to claim 1, wherein said irradiating means is a laser light emitting diode dedicated to detection for irradiating a laser beam to the photoreceptor belt, and said light receiving means is a photodetector for receiving laser beam light from said laser light emitting diode. An image forming apparatus using the photosensitive belt according to claim 2 . Wherein said laser light emitting diode and photodetector, an image forming apparatus using the photoreceptor belt according to claim 4, characterized in that it is arranged in the vicinity of each of a plurality of color developing devices. 6. A laser light source for irradiating an image signal with a laser beam.
On a photoreceptor belt on which an electrostatic latent image is formed and development is performed
Image forming apparatus using photoreceptor belt to detect reference position of image
Extends in the sub-scanning direction and is predetermined in the main scanning direction.
Form the reference position detection holes of multiple slits at intervals or non-equal intervals
A photoreceptor belt form, the reference position detection of multiple slits formed on the photosensitive belt
Irradiating the exit hole with laser beam light while scanning
Means for irradiating a laser beam, and the irradiation having passed through the reference position detection holes of the plurality of slits
Light receiving means for receiving the laser beam light from the means, and a plurality of slits from the laser beam light received by the light receiving means.
The pattern in the main scanning direction of the reference position detection hole
The main scanning direction pattern recognition unit and the sub-scanning
Rezabi over of the beam light scanning line number of the in the direction
Normal detection of the reference position detection hole based on the count value
Outputs the reference position detection signal when the width counter in the sub-scanning direction is output.
An image forming apparatus using the photoreceptor belt, characterized in that it comprises a isolation portion, a. 7. The main scanning direction pattern recognizing unit compares the pattern of an output signal from a light receiving unit with a predetermined set value corresponding to a reference position detection hole of a plurality of slits. 7. The image forming apparatus using a photoreceptor belt according to claim 6, further comprising a pattern comparing unit that outputs an output signal from the light receiving unit in the same case. 8. A pattern of an output signal from said light receiving means and said plurality of slots as said sub-scanning direction width counting section.
The predetermined set value corresponding to the reference position detection hole of the
When they are the same, the main scanning direction pattern recognition unit
Laser in the sub-scanning direction based on the output signal
Count to count the number of scanning lines of light beam
The values counted by this counter and the
Scanning of laser beam light in the sub-scanning direction of the quasi-position detection hole
Comparison with the set value corresponding to the number of
If the reference position detection hole is
7. An image forming apparatus using a photoreceptor belt according to claim 6 , further comprising: a comparator for outputting a reference position detection signal indicating the following .