JP2000321842A - Image forming device and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of sensors provided in a device so as to realize the reduction of cost and to simplify constitution so as to make the device compact by discriminating the kind of a recording medium according to the detected result obtained when the carried recording medium passes through a detection means. SOLUTION: This device is constituted so that the kind of the recording medium is discriminated according to the detected result obtained when the carried recording medium passes through the detection means. In this device, registration detecting sensors 8a and 8b are used also as one part of the function of a transfer discrimination sensor 12. The sensors 8a and 8b are arranged to fit to the position of the band of an OHT with a band when transfer material is vertically set so that the band of the OHT can be detected even in the case whether the transfer material is vertically set or horizontally set. Since either pair of bands out of the bands (a) to (d) is put on the OHT vertically set, the sensors 8a and 8b are arranged so that the bands (a) to (d) orthogonally crossing a carrying direction may pass under either of the sensors 8a and 8b when the transfer material is carried by a transfer material carrying belt 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus and a method for controlling the image forming apparatus.

[0002]

2. Description of the Related Art The structure of a conventional image forming apparatus will be described below with reference to the drawings.

FIG. 6 is a schematic sectional view illustrating the structure of a conventional image forming apparatus. In FIG. 6, a four-drum multi-color image forming apparatus, which is an electrophotographic full-color laser beam printer having four photosensitive drums, will be described as an example. The image forming apparatus shown in FIG. 6 includes an oilless fixing device.

Referring to FIG. 6, reference numeral 1000 denotes a color laser printer, which is an electrophotographic full-color laser beam printer having four photosensitive drums. 1Y, 1M, 1
C and 1Bk are photosensitive drums, one for one color developer.
The corresponding photosensitive drums. In the color laser printer 1000, yellow (1Y) and magenta (1Y)
M), four photosensitive drums for cyan (1C), and black (1Bk).

[0005] Laser scanner units 2Y, 2M, 2C and 2Bk form latent images on the photosensitive drums 1Y, 1M, 1C and 1Bk in response to a laser on / off signal generated from an image signal sent from the controller 100. It is for. 3Y, 3M, 3C, and 3Bk are developer replenishment units, and the photosensitive drums 1Y, 1M, 1C, and 1
The latent images formed on Bk are developed by developing units 4Y, 4M, 4C,
This is for replenishing the developing devices 4Y, 4M, 4C, and 4Bk with the developer so that the developer does not run short when developing with 4Bk.

Reference numerals 5Y, 5M, 5C, and 5Bk denote transfer rollers, which transfer the developed images formed on the photosensitive drums 1Y, 1M, 1C, and 1Bk from a paper feed unit 7a or 7b, and transfer the developed images onto a transfer material transport belt 6. This is for transferring to a transfer material that is sucked and conveyed. The paper feed units 7a and 7b are for storing and placing the transfer material. In this conventional example,
7a is a cassette sheet feeding unit, and 7b is a manual sheet feeding unit.

Reference numeral 8 (8a, 8b) denotes a registration correction pattern detection sensor (hereinafter, registration detection sensor).
In order to detect information for correcting the registration of the image transferred by each of the photosensitive drums 1Y, 1M, 1C, and 1Bk, it is arranged at two places as shown in FIG. This is for detecting a registration correction pattern to be formed.

The registration detection sensor 8 includes a light emitting unit and a light receiving unit (not shown), and irradiates light from the light emitting unit to the transfer material transport belt 6 or the transfer material transported by the transfer material transport belt 6, and transfers the light. The registration correction pattern is detected by receiving the reflected light from the material transport belt 6 or the transfer material transported by the transfer material transport belt 6 at the light receiving unit.

Further, in this embodiment, the reflection detection sensor 8 is described using a reflection type sensor for receiving the reflected light from the transfer material conveyance belt 6 as an example. A transmission type sensor that irradiates the belt 6 or the transfer material conveyed by the transfer material conveyance belt 6 and receives light transmitted through the transfer material conveyance belt 6 or the transfer material at a light receiving unit may be used.

Reference numeral 9 denotes a fixing unit, which is an oilless fixing device for fixing an image transferred to a transfer material. 10,
Reference numeral 11 denotes a paper discharge unit which discharges the transfer material on which the image is fixed face up and face down, respectively.

Reference numeral 12 (12a, 12b) denotes a transfer material identification sensor, which is plain paper, OHT (Over Head Trans
parance sheet (hereinafter OHT), O with obi
HT, which detects an OHT band with an oil fixing band that damages the fixing unit 9 of an electrophotographic multicolor image forming apparatus that performs oilless fixing, and selects an optimal fixing sequence. Like paper and OH
T, and is constituted by a transmission sensor using a prism 15 as shown in FIG. A pre-registration sensor 13 detects the leading end of the conveyed transfer material.

The controller 100 includes a CPU 101, R
It includes an AM 102, a ROM 103, and the like, controls the color laser printer 1000, and transmits and receives image data to and from an external device such as a host computer.

As described above, the color laser printer 100
0, the photosensitive drums 1Y, 1M, 1C, and 1Bk, which can be separated in one row in the transfer material transport direction, and the photosensitive drums 1Y and 1B
M, 1C, 1Bk or less laser scanner units 2Y, 2M, 2C, 2Bk and respective photosensitive drums 1
Transfer rollers 5Y, 5M, 5C and 5Bk for transferring images developed on Y, 1M, 1C and 1Bk to a transfer material, a transfer material transport belt 6 for transporting the transfer material, and an image transferred to the transfer material. The image forming apparatus includes a fixing unit 9 for fixing, a controller 100 for controlling an engine unit to generate a pattern for registration correction, and a registration detection sensor 8 for reading a pattern generated on the transfer material conveying belt 6.

FIG. 7 shows the transfer material identification sensor 1 shown in FIG.
2 (12a, 12b) and the registration detection sensor 8 (8a, 8
It is a figure explaining arrangement of b). FIG. 7 shows the transfer material conveying belt 6 shown in FIG. 6 as viewed from above.

In FIG. 7, a transfer material identification sensor 12a,
12b identifies the band of the OHT with the band, and
HT. Reference numerals 8a and 8b are registration detection sensors.
As described above, the conventional color laser printer 1000 includes the two transfer material identification sensors 12a and 12b and the two registration detection sensors 8a and 8b.

FIG. 8 shows the transfer material identification sensor 1 shown in FIG.
FIG. 3 is a diagram for explaining a method of identifying a transfer material according to No. 2;

In FIG. 8, the transfer material identification sensor 12 emits light L. The light L passes through the transfer material transport belt 6, is reflected by the prism 15, and is received by the light receiving portion of the transfer material identification sensor 12. The transfer material is identified based on the detection level of the light receiving unit.

In the conventional image forming apparatus such as a color laser printer constructed as described above, the cause of the damage of the fixing unit 9 by the OHT with the oil fixing band is as follows.
It is known that this is a special coating on the OHT with a band, which is made to obtain a high quality image. The detection voltage level of the paper, OHT, and OHT bands in the transfer material identification sensor 12 is as follows: paper> OHT band> OHT (or paper <OH
T band <OHT, the direction of the inequality sign differs depending on the configuration of the detection circuit), and particularly, the detection level of the OHT band is detected from a value close to the detection level of the paper due to the individual difference of the transfer material identification sensor 12 and the mounting accuracy. It is known that there is a large variation up to a value close to the level.

The detection method is performed according to the following procedure. At the time of initializing the main body, a detection level in a state where there is nothing between the transfer material identification sensor 12 and the prism 15 is fetched, and a slice level is determined from the fetched value and the maximum voltage. The slice level determined here is OHT (transparent part), paper,
This is a level for identifying an OHT band, and the slice level is determined every time at the time of initializing. When the print sequence is performed after the slice level is determined,
The detection level of the transfer material identification sensor 12 when the leading end of the transfer material fed from the feeding units 7a and 7b is temporarily stopped by the pre-registration sensor 13 is read.

The transfer pattern of the transfer material is, as shown in bands a to h shown in FIG.
There are four types (horizontal, vertical) and OHT front, back, left and right.

FIG. 9 is a plan view for explaining the arrangement of bands attached to the OHT with bands.

In FIG. 9 (a), a belt O
It shows a combination of bands attached to the HT, and one set of bands given the same reference numerals is attached to the OHT sheet.

In FIG. 9B, the band O
It shows a combination of bands attached to the HT, and one set of bands given the same reference numerals is attached to the OHT sheet.

Therefore, as shown in FIG.
transfer material identification sensor 12a for detecting e and g and bands b, d,
Two transfer material identification sensors 12b for detecting f and h are required, and the respective transfer material identification sensors 12a and 12b
When the leading end of the transfer material is temporarily stopped by the pre-registration sensor 13, the transfer material is disposed at a position where the bands a, e, b, and f can be detected. At this time, if the detection levels of the two transfer material identification sensors 12a and 12b are both paper and OHT bands, the transferred transfer material is determined to be paper and printing is continued. If one of the detection levels of the two transfer material identification sensors 12a and 12b is in the paper or OHT band and the other is in the OHT band, the transferred transfer material is determined to be the OHT with the band, and the printing operation is stopped. To warn the user. Also, 2
When the detection levels of the two transfer material identification sensors 12a and 12b are both OHT, the temporarily stopped transfer material is conveyed again at a predetermined timing, and then the transfer material identification is performed until the rear end of the transfer material passes through the sensor 13 before the registration. Sensors 12a, 12
b, and monitors the transfer material identification sensor 1 during the monitoring.
If the detection level does not change in any of the two cases, it is determined that the sheet is OHT, and printing is continued. If one of the levels fluctuates to the level of the paper / OHT band, it is determined that the sheet is OHT and the printing operation is stopped to stop the printing. Warning.

The transfer material identification sensor 12 includes an OHT with a band for oil fixing and an OHT for oilless fixing with a paper feeding unit 7a,
7b, there is a dedicated OHT for oil fixing that damages the fixing unit for oilless fixing. If there is an OHT for oil fixing, it is difficult for an electrophotographic multicolor image forming apparatus such as a color laser printer to perform oilless fixing. It is an effective sensor.

[0026]

However, it is known that the amount of light received by the transmission type sensor using the prism 15 has a large variation among the individual sensors and that the variation in the mounting accuracy greatly affects the amount of received light. And
In the conventional OHT detection method with a band, the value of the intermediate level when the band is detected is greatly affected. Therefore, the detection circuit and the detection value processing method must be determined in consideration of the yield of the sensor while suppressing the variation between the mounting bodies, so that there is a problem that the design procedure becomes complicated.

Further, since a large number of sensors must be mounted, there is a problem in that the color laser printer is reduced in size, and the cost is increased.

The present invention has been made to solve the above problems, and an object of the present invention is to reduce the time required for studying the design of an apparatus for identifying the type of transfer material,
An image forming apparatus and a control of the image forming apparatus that can improve the development efficiency, reduce the number of sensors provided in the apparatus, realize cost reduction, and further simplify the configuration of the apparatus and easily downsize the apparatus. It is to provide a method.

[0029]

According to a first aspect of the present invention, there is provided a recording medium conveyed by a conveying means (a transfer material conveying belt 6 shown in FIG. 6) or a plurality of recording media for forming an image on the conveying means. Image forming means (each unit 1Y, 1M,
1C, 1Bk to 5Y, 5M, 5C, 5Bk, etc.) and detection means (registration detection sensors 8a, 8b shown in FIG. 1) for reading the image shift correction patterns formed by the respective image forming means. An image forming apparatus having
One having identification means (controller 100 shown in FIG. 6) for identifying the type of the recording medium according to the detection result of the detection means when the recording medium conveyed by the conveyance means passes through the detection means It is.

According to a second aspect of the present invention, there is provided a recording medium conveyed on a conveying means (a transfer material conveying belt 6 shown in FIG. 6) or a plurality of image forming means for forming an image on the conveying means (see FIG. Each part 1Y, 1M, 1C, 1Bk-5 shown in 6
Y, 5M, 5C, 5Bk, etc.), and detecting means for detecting reflected light from the transport means or the recording medium (registration detection sensors 8a, 8b shown in FIG. 1). And detecting a shift of an image formed by each of the image forming units based on a detection result of the detecting unit when the image shift correction pattern formed on the transporting unit or the recording medium passes through the detecting unit. Detecting means (a controller 100 shown in FIG. 6); and identifying means for identifying a type of the recording medium based on a detection result of the detecting means when the recording medium conveyed on the conveying means passes through the detecting means. (The controller 100 shown in FIG. 6).

According to a third aspect of the present invention, the detecting means is a reflection type sensor (registration detection sensors 8a, 8b shown in FIG. 1).
The light-receiving portion (not shown) receives reflected light from the transfer material transport belt 6 or the transferred transfer material at a light receiving portion (not shown).

According to a fourth aspect of the present invention, the discriminating means discriminates between an opaque recording medium and a transparent recording medium (OHT without band, OHT with band) according to the detection result of the detecting unit. .

According to a fifth aspect of the present invention, the identification means includes an opaque recording medium, a transparent recording medium without a band (OHT without a band), and a transparent recording medium with a band (with a band) according to the detection result of the detection means. OHT).

According to a sixth aspect of the present invention, the identification means identifies the opaque recording medium, the transparent recording medium for oil fixing, and the transparent recording medium for oilless fixing according to the detection result of the detecting means. It is.

According to a seventh aspect of the present invention, the conveying means is constituted by a belt (a transfer material conveying belt 6 shown in FIG. 6).

An eighth invention according to the present invention has type detecting means (transfer material identifying sensor 12 shown in FIG. 1) for identifying the type of the recording medium, and the identifying means detects the type of the recording medium. The type of the recording medium is identified according to a result and a detection result of the detection unit.

In a ninth aspect according to the present invention, the identification means identifies a type of the recording medium which cannot be identified by the type detection means according to a detection result of the detection means.

According to a tenth aspect of the present invention, there is provided a control means for controlling an image forming operation on the recording medium in accordance with the identification result of the identification means (the controller 10 shown in FIG. 6).
0).

An eleventh invention according to the present invention is characterized in that said control means, when the type of said recording medium is identified by said identification means as a type in which image formation by said image forming means is not possible, This is to stop the image forming operation on the recording medium.

According to a twelfth aspect of the present invention, there is provided a fixing unit (fixing unit 9 shown in FIG. 6) for oil-less fixing an image on the recording medium, and the control unit controls the recording by the identification unit. When the medium is identified as a transparent recording medium with a band, the image forming operation on the recording medium is stopped.

According to a thirteenth aspect of the present invention, there is provided a fixing unit (fixing unit 9 shown in FIG. 6) for fixing an image to the recording medium without oil, and the control unit controls the recording by the identification unit. When the medium is identified as a recording medium for oil fixing, the image forming operation on the recording medium is stopped.

According to a fourteenth aspect of the present invention, the detecting means is disposed at a position where at least one band of the transparent recording medium with a band can be detected.

A fifteenth invention according to the present invention comprises a plurality of the detecting means.

In a sixteenth aspect according to the present invention, the plurality of detecting means are arranged at a position where at least one band of the transparent recording medium with a band can be detected, and a direction orthogonal to a conveying direction of the conveying means. Is disposed at the farthest position (disposition of the registration detection sensors 8a and 8b shown in FIG. 1).

According to a seventeenth aspect of the present invention, there is provided a recording medium conveyed by a conveying means (the transfer material conveying belt 6 shown in FIG. 6) or a plurality of image forming means for forming an image on the conveying means (FIG. 6). 1Y, 1M, 1C, 1Bk
To 5Y, 5M, 5C, 5Bk, etc.) and detecting means for reading the image shift correction pattern formed by each of the image forming means (the registration detection sensor 8a,
8b), wherein the type of the recording medium is identified based on a detection result of the detection means when the recording medium conveyed by the conveyance means passes through the detection means. (Steps (6) and (8) in the flowchart shown in FIG. 3).

According to an eighteenth aspect of the present invention, there is provided a recording medium conveyed on a conveying means (the transfer material conveying belt 6 shown in FIG. 6) or a plurality of image forming means for forming an image on the conveying means (see FIG. Each of the parts 1Y, 1M, 1C, and 1Bk shown in FIG.
5Y, 5M, 5C, 5Bk, etc.), detecting means (registration detection sensors 8a, 8b shown in FIG. 1) for detecting reflected light from the conveying means or the recording medium, and the conveying means or the Detecting means for detecting a shift of an image formed by each of the image forming means in accordance with a detection result of the detecting means when an image shift correcting pattern formed on a recording medium passes through the detecting means (see FIG. 6) Controller 10
0), wherein the detecting means detects reflected light when the recording medium conveyed on the conveying means passes through the detecting means (see FIG. 3). Step (6) of the flowchart,
(8)) and an identification step of identifying the type of the recording medium based on the detection result of the detection step (steps (6) and (8) in the flowchart shown in FIG. 3).

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment will be described below with reference to the drawings.

The image forming apparatus shown in this embodiment also has the configuration shown in FIG.
Are different from each other in the arrangement and the number of the registration detection sensors 8.

Hereinafter, an example of the arrangement of the registration detection sensor 8 and the transfer material identification sensor 12 in the multi-color image forming apparatus such as the color laser printer 1000 shown in the first embodiment will be described with reference to FIG.

FIG. 1 is a view for explaining the arrangement of the registration detection sensor 8 and the transfer material identification sensor 12 shown in FIG.

In FIG. 1, the registration detection sensors 8a and 8b are provided with a band O regardless of whether the transfer material is set vertically or horizontally.
In order to detect the HT band, it is arranged in accordance with the position of the band in the vertical position. For example, in the OHT with a vertical band shown in FIG. 1, any one set of the bands a, b, c, and d is attached, so that the bands a, b, c, and d are orthogonal to the transport direction.
Is disposed so as to pass under one of the registration detection sensors 8a and 8b when the sheet is conveyed by the transfer material conveying belt 6.

Note that the registration detection sensors 8a and 8b are
At least one T band may be detected, and may be arranged at positions farthest from each other in a direction orthogonal to the transport direction. With this configuration,
Registration can be corrected more accurately.

In the present embodiment, one transfer material identification sensor 12 is provided, the transfer material identification is performed by one transfer material identification sensor 12, and the functions of the registration detection sensors 8a and 8b and the transfer material identification sensor Twelve functions are different from the conventional example.

The transfer material identification sensor 12 and the registration detection sensor 8 according to this embodiment will be described below from the description of the transfer material identification method.
The functions a and 8b will be described.

When the power supply (not shown) of the color laser printer 1000 is turned on or the door is closed after the door is opened, the controller 100 sends an initial sequence to the engine unit (image forming unit formed by the units 1 to 11 shown in FIG. 6). To start. In the initial sequence, registration correction, density correction, and the like are performed.

Hereinafter, an example of a registration correction subroutine in the image forming apparatus of this embodiment will be described with reference to the flowchart shown in FIG.

FIG. 2 is a flowchart illustrating an example of a first data processing procedure in the image forming apparatus according to the present embodiment, and corresponds to the processing executed by the controller 100 shown in FIG. Note that (1) to (4) show each step.

First, a voltage level detected by a light receiving portion (not shown) of the registration detection sensors 8a and 8b in a state where no image is transferred onto the transfer material conveying belt 6 is read (1). Next, it is determined whether or not a predetermined voltage level is obtained in the light receiving units of the registration detection sensors 8a and 8b (2). If the voltage level is not at the predetermined voltage level, the detection by the registration detection sensors 8a and 8b is performed. The light emission amount is corrected (3), and the processing of steps (1) to (3) is repeated until a predetermined voltage level is obtained in the light receiving sections of the registration detection sensors 8a and 8b.

In step (2), when a predetermined voltage level is obtained, processing for correcting registration is performed (4), and the registration correction subroutine ends.

When the initial sequence as described above is completed and the print sequence is started from the standby state, the transfer material is fed to the feeding unit 7 at a predetermined timing.
When the sheet is fed from a and 7b and reaches the pre-registration sensor 13, it is temporarily stopped. At the position where the transfer material is temporarily stopped, the detection level of the transfer material identification sensor 12 is read, and the paper, the OHT, and the OHT with a band are identified, that is, whether the fed transfer material is paper or a light-transmitting sheet. I do.

The transfer material identification sensor 12 is provided with an OH
When T is conveyed, the transfer material is
When the transfer material identification sensor 12 is temporarily stopped when it reaches
In addition, it is arranged so as to be located between the front end and the rear end of the transfer material.

Since there is no problem if the detection voltage level can be determined in a binary manner between paper and OHT, the transfer material identification sensor 12 can be constructed simply and inexpensively. When the transfer material is identified by the transfer material identification sensor 12 and the transfer material is paper, the transfer and fixing are performed in a normal print sequence, and the transfer material is discharged to the paper discharge unit 10 or 11. The transfer material is O by the transfer material identification sensor 12.
HT, that is, when the transfer material is identified as a light-transmitting sheet, the transfer material is transferred to the photosensitive drum 1 of each color by the transfer material transport belt 6.
The developed images developed on Y, 1M, 1C, and 1Bk are transferred to the fixing unit 9 while being transferred by the transfer rollers 5Y, 5M, 5C, and 5Bk arranged opposite to the photosensitive drums 1Y, 1M, 1C, and 1Bk of each color. It is conveyed toward.

During conveyance, the registration detection sensors 8a and 8b read the respective detection levels at the timing of being conveyed to the band detectable position when the band of the OHT with the band is at the leading end by the time management from the sensor 13 before the registration. , With a predetermined slice level. The registration detection sensors 8a and 8b are corrected so that the detection level becomes constant by light amount correction at the time of initializing.

Therefore, the amount of reflected light in the band greatly depends on the variation in reflectance on the OHT side, and the slice level is set so as to cover the entire range of variation in reflectance on the OHT side. As a result of the comparison, if both detection levels are OHT without a band, printing is continued, and if either one of the detection levels is OHT with a band, the printing operation is stopped and a warning is issued to the user.

If no band is detected at the leading end of the transfer material, the respective detection levels are read at the timing when the transfer material is conveyed to the band detectable position when the OHT with band is at the rear end. As a result of comparison with a predetermined slice level, if both of the detection levels are OHT without a band, printing is continued, the fixing is performed by the fixing unit 9, and the paper discharging unit 10 is fixed.
Alternatively, the transfer material is discharged to 11. If one of the detection levels is OHT with a band, the printing operation is stopped and a warning is issued to the user.

Hereinafter, the above processing will be further described with reference to the flowchart shown in FIG.

FIG. 3 is a flowchart for explaining an example of the second data processing procedure in the image forming apparatus of the present embodiment, and corresponds to the processing executed under the control of the controller 100 shown in FIG. (1) to (11)
Indicates each step.

First, when the print sequence is started, the transfer material is fed to the pre-registration sensor 13 (1), and whether the transfer material fed by the transfer material identification sensor 12 is paper, OHT, or OHT with a band is determined. If it is determined (2) that the transfer material is determined to be paper, the image is transferred and fixed to the transfer material by a normal print sequence (13), and the process ends.

On the other hand, if it is determined in step (2) that the transfer material is an OHT or an OHT with a band, that is, a light transmissive sheet, image formation is performed on the transfer material in a print sequence suitable for the OHT (3). For example, by performing time management such as measuring the transport time by a timer (not shown) or the like, is it time to reach the leading end of the transfer material, which is the band detectable position, at the registration detection sensors 8a and 8b shown in FIG. If it is determined (4) that it is not the time for the leading edge of the transfer material to arrive at the registration detection sensors 8a and 8b, the process returns to step (4) and waits until it arrives.

On the other hand, if it is determined in step (4) that it is time for the leading edge of the transfer material to arrive at the registration detection sensors 8a and 8b, the registration detection sensor 8
The reflected light from the transfer material is detected at a and 8b (5). Next, the detection result is compared with the slice level (6). If one of the detection levels of the registration detection sensors 8a and 8b is the OHT band level, the transfer material is identified as the OHT with the band, and step (11). Proceed to.

On the other hand, when the detection levels of the registration detection sensors 8a and 8b are both OHT levels, the rear end of the transfer material, which is the band detectable position, arrives at the registration detection sensors 8a and 8b shown in FIG. It is determined whether or not the time has come (7), and if it is determined that it is not time for the rear end of the transfer material to arrive at the registration detection sensors 8a and 8b, the process returns to step (7) and waits for arrival.

On the other hand, if it is determined in step (7) that it is time to reach the leading end of the transfer material to the registration detection sensors 8a and 8b, the registration detection sensor 8
The reflected light from the transfer material is detected by a and 8b (8). Next, the detection result is compared with the slice level (9), and when one of the detection levels of the registration detection sensors 8a and 8b is the OHT band level, the transfer material is identified as the OHT with the band,
Proceeding to step (11), when both the detection levels of the registration detection sensors 8a and 8b are at the OHT level, the transfer material is identified as the OHT without the band, and the image forming operation is continued (10). The process ends.

On the other hand, in step (11), the OHT
If the image formation is continued in step (1), the fixing unit 9 may be damaged. Therefore, the operation of the printer is stopped (11), and a warning to the user, for example, via a host computer (not shown) connected to the color laser printer or a network, is provided. OHT attached to a printer server connected to the printer, a display unit (not shown) of the color laser printer 1000, etc.
That is, the fact that the printing operation has been stopped due to an attempt to form an image on the OHT for oil fixing is displayed to notify the user (11), and the processing is terminated.

As described above, in the first embodiment, setting the slice level of the transfer material identification sensor 12 is simplified by making the registration detection sensor also have a part of the function of the transfer material identification sensor 12. And the number of sensors can be reduced.

[Second Embodiment] In the first embodiment,
One transfer material identification sensor 12 for identifying whether the fed transfer material is paper or a light transmissive sheet, and two registration detection sensors 8a and 8b for identifying OHT without a band and OHT with a band.
In the present embodiment, a case where the transfer material is identified by the two registration detection sensors without the transfer material identification sensor will be described.

In the present embodiment, the color laser printer 100 shown in FIG.
0 will be described as an example, but the transfer material identification sensor is not provided as described above.

FIG. 4 is a plan view for explaining an example of the arrangement of the registration detection sensor 8 shown in FIG.

In FIG. 4, the registration detection sensors 8a and 8b are located at the positions of the bands in the vertical position so that the transfer material can be detected whether the transfer material is set vertically or horizontally, as in the first embodiment. It is arranged together. Further, the transfer material identification sensor is not provided, and the registration detection sensor 8 substitutes all of the transfer material identification.

Next, the registration detection sensor 8 in the present embodiment
A method for identifying a transfer material using the method will be described.

When the power of the main body of the color laser printer 1000 is turned on or the door is closed after the door is opened,
The engine unit starts an initial sequence. In the initial sequence, registration correction, density correction, and the like are performed. In the registration correction subroutine, the control shown in the flowchart of FIG. 2 is performed in the same manner as in the first embodiment.

When the initial sequence is completed and the print sequence is started from the standby state, the transfer material is fed from the feeding unit 7 (7a, 7b) at a predetermined timing. Once stopped. The transfer material once stopped starts to be conveyed again at a predetermined timing, and the developed image developed on the photosensitive drum 1 of each color by the transfer material conveying belt 6 is arranged to face the photosensitive drum 1 of each color. The sheet is conveyed toward the fixing unit 9 while being transferred by the transfer roller 5.

During transportation, the registration detection sensor 8 is
From the time management from 3, the detection level of each of the registration detection sensors 8a and 8b is read at the timing of being transported to the band detectable position when the band of the banded OHT is at the leading end, and compared with the predetermined slice level. Then, the OHT with the paper / band is identified.

The registration detection sensors 8a and 8b are corrected by initial light quantity correction so that the detection level becomes constant. The amount of reflected light in the band largely depends on the variation in the reflectance on the OHT side, and the slice level is set so as to cover the entire range of variation in the reflectance on the OHT side.

As a result of comparison, both detection levels were determined to be paper / paper.
If the level is OHT with band, it is determined that the sheet is paper, and printing is continued. As a result of comparison, if one of the detection levels is OHT with paper / band and the other is at the level of OHT, O
It judges as HT, stops the printing operation, and warns the user.

As a result of the comparison, if both the detection levels are OHT levels, the transfer material is conveyed to the band detectable position when the OHT with band is at the rear end. Is read and compared with a predetermined slice level. As a result of the comparison, if both the detection levels are OHT without a band, the printing is continued, the fixing is performed by the fixing unit 9, and the transfer material is discharged to the paper discharge unit 10 or 11. Either detection level is OH with band
If T, the printing operation is stopped and a warning is issued to the user.

Hereinafter, the above processing will be simply described with reference to the flowchart shown in FIG.

FIG. 5 is a flowchart for explaining an example of the third data processing procedure in the image forming apparatus of the present embodiment, and corresponds to the processing executed under the control of the controller 100 shown in FIG. (1) to (12)
Indicates each step.

First, when the print sequence is started, the transfer material is fed to the pre-registration sensor 13 (1), and execution of image formation is started in a normal print sequence (2). Is measured, it is determined whether or not the leading end of the transfer material, which is the band detectable position, has arrived at the registration detection sensors 8a and 8b shown in FIG. 1 (3), and the leading end of the transfer material is detected at the registration detection sensors 8a and 8b. If it is determined that has not arrived, it returns to step (3) and waits until it arrives.

On the other hand, if it is determined in step (3) that the leading end of the transfer material has arrived at the registration detection sensors 8a and 8b, the registration detection sensor is detected at the timing when the leading end of the transfer material arrives at the registration detection sensors 8a and 8b. The reflected light from the transfer material is detected at 8a and 8b (4).

Next, in step (4), the detection level of the reflected light detected by the registration detection sensors 8a and 8b is compared with a predetermined slice level (5), and the detection levels of the registration detection sensors 8a and 8b are compared. Are both paper or OHT band levels, the transfer material is identified as paper, the image forming operation is continued in a normal print sequence (6), and the process ends.

On the other hand, if the comparison results in step (5) are both OHT levels,
HT or OHT with band, and proceed to step (7).
If one is at the OHT level and the other is at the paper or OHT band level, the transfer material is identified as a banded OHT, and step (1) is performed.
Proceed to 1).

In step (7), the rear end of the transfer material, which is a band detectable position, arrives at the registration detection sensors 8a and 8b shown in FIG. Judge if the time is up,
If it is determined that it is not time for the rear end of the transfer material to arrive at the registration detection sensors 8a and 8b, the process returns to step (7) and waits until the arrival.

On the other hand, if it is determined in step (7) that it is time to arrive at the rear end of the transfer material, the rear end of the transfer material at the band detectable position is detected by the registration detection sensors 8a and 8b.
The reflected light from the transfer material is detected by the registration detection sensors 8a and 8b at the timing when the data arrives at (8).

Next, the detection result is compared with the slice level (9). If both the detection levels of the registration detection sensors 8a and 8b are at the OHT level, the transfer material is stripped without the band.
T is identified, the image formation is continued in the OHT print sequence (10), and the process ends. On the other hand, one of the detection levels of the registration detection sensors 8a and 8b is paper or OHT.
If it is a band, the transfer material is identified as an OHT with a band, and the process proceeds to step (11).

In step (11), if image formation is continued with the OHT with a band, the fixing unit 9 may be damaged. Therefore, the printer operation is stopped and a warning is issued to the user, for example, the printer is connected to a color laser printer. Host computer (not shown), printer server connected via network, color laser printer 100
A notification that the printing operation has stopped due to an attempt to form an image on an OHT with a band, that is, an OHT for oil fixing, is displayed and displayed on a display unit (not shown) of No. 0, and the process is ended (12).

As described above, in the second embodiment, the transfer material identification sensor can be eliminated by using all the functions of the transfer material identification sensor by the registration detection sensors 8a and 8b, thereby further reducing the cost. Can be expected.

Therefore, by performing the transfer material identification function by the registration mark detection sensor for registration correction, the examination of the transfer material identification means can be shortened, the development efficiency can be improved, and it is necessary for the conventional image forming apparatus. Since the number of existing transfer material identification sensors can be reduced, cost can be reduced.

According to each of the above embodiments, the electrophotographic 4
A registration detection sensor (pattern detection sensor) used for registration correction, which is indispensable for a continuous drum type multicolor image forming apparatus, is used as a transfer material identification sensor during printing, so that the remaining transfer material identification sensor can be easily configured. Can be. In addition, by providing the registration detection sensor with all the functions of the transfer material identification sensor, it is possible to significantly reduce costs.

Further, the above embodiments may be combined.

Further, in each of the above embodiments, a color laser printer (multicolor image forming apparatus) is described as an example, but various image forming apparatuses such as an electrophotographic apparatus,
Digital copiers, monochrome copiers, color laser copiers, laser beam printers, thermal transfer printers, facsimile machines, multifunction copiers with copy and / or print and / or facsimile functions, etc.
In addition, the technology described in the present embodiment may be applied to a control device, an information processing device, a data processing device, a computer, and the like that control various image forming apparatuses.

As described above, the storage medium storing the program code of the software for realizing the functions of the above-described embodiment is supplied to the system or the apparatus, and the computer (or CPU or MP) of the system or the apparatus is supplied.
It goes without saying that the object of the present invention is also achieved when U) reads out and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

Examples of a storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, and C
DR, magnetic tape, nonvolatile memory card, RO
M, EEPROM and the like can be used.

The functions of the above-described embodiments are implemented when the computer executes the readout program codes, and the OS (Operating System) running on the computer is executed based on the instructions of the program codes. ) And the like perform part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, The CPU provided in the function expansion board or function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

The present invention also relates to a system including a plurality of devices, for example, an information processing system, a printing system,
Image processing system, image forming system, control system,
Even if applied to a print control system, an image processing control system, an image formation control system, etc.
For example, information processing devices, printing devices, image processing devices, image forming devices, control devices, print control devices, image processing control devices,
The present invention may be applied to an image forming control device or the like. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading a storage medium storing a program represented by software for achieving the present invention into the system or the apparatus, the system or the apparatus can enjoy the effects of the present invention. .

Further, by downloading and reading out a program represented by software for achieving the present invention from a database on a network using a communication program, the system or apparatus can be
It is possible to enjoy the effects of the present invention.

[0108]

As described above, the first embodiment according to the present invention is described.
According to the invention, there is provided a recording medium conveyed by a conveying unit or a plurality of image forming units for forming an image on the conveying unit, and a detecting unit for reading an image shift correction pattern formed by each of the image forming units. The image forming apparatus includes an identification unit that identifies a type of the recording medium according to a detection result of the detection unit when the recording medium conveyed by the conveyance unit passes through the detection unit. The type of the recording medium can be identified using the detection sensor, the number of sensors can be reduced, the apparatus can be easily made compact, and the cost can be reduced.

According to a second aspect, there is provided an image forming apparatus having a recording medium conveyed on a conveying means or a plurality of image forming means for forming an image on the conveying means, wherein the conveying means or the recording medium is provided. Detecting means for detecting the reflected light from the image forming means, and the image forming means based on the detection result of the detecting means when the image shift correction pattern formed on the conveying means or the recording medium passes through the detecting means. Detecting means for detecting a displacement of an image to be formed, and identification for identifying a type of the recording medium based on a detection result of the detecting means when the recording medium conveyed on the conveying means passes through the detecting means Means, the detection of the registration mark and the identification of the recording medium can be performed using a common sensor, and the number of sensors can be reduced and the apparatus can be made more compact. It is possible to perform, it can be realized cost reduction.

According to the third aspect, since the detection means is constituted by a reflection type sensor, the type of the recording medium can be surely identified by a simple judgment process.

According to the fourth aspect, the discriminating means discriminates between the opaque recording medium and the transparent recording medium according to the detection result of the detecting means. Therefore, the recording medium is transparent using the registration detection sensor. Can be identified.

According to the fifth aspect, the discriminating means discriminates the opaque recording medium, the non-banded transparent recording medium and the banded transparent recording medium according to the detection result of the detecting means. It can also be used to identify whether the recording medium is transparent and whether the transparent transfer material has a band.

According to the sixth aspect, the discriminating means discriminates the opaque recording medium, the oil fixing transparent recording medium, and the oilless fixing transparent recording medium according to the detection result of the detecting means. It is possible to identify whether the medium is transparent and to identify the fixing method of the transparent recording medium.

According to the seventh aspect, since the transporting means is constituted by a belt, the type of the transfer material transported by the belt can be identified.

According to the eighth invention, there is provided a type detecting means for identifying the type of the recording medium, wherein the identifying means is configured to perform the type detection according to the detection result of the type detecting means and the detection result of the detecting means. Since the type of the recording medium is identified, the type of the transfer material can be reliably identified even if the recording medium identification sensor is simplified.

According to the ninth aspect, the identification means identifies the type of the recording medium that cannot be identified by the type detection means according to the detection result of the detection means. Many types of recording media can be identified.

According to the tenth aspect, since the control means for controlling the image forming operation on the recording medium according to the identification result of the identifying means is provided, the image can be formed by the operation suitable for the type of the recording medium. Quality images can be obtained.

According to the eleventh aspect, the control means includes:
When the type of the recording medium is identified by the identification unit as a type in which image formation by the image forming unit is not possible, the image forming operation on the recording medium is stopped. When transported, the image forming operation can be stopped without damaging the printer unit.

According to a twelfth aspect of the present invention, there is provided fixing means for fixing an image to the recording medium without oil, and the control means identifies the recording medium as a transparent recording medium with a band by the identification means. In this case, the image forming operation on the recording medium is stopped. Therefore, when the recording medium is identified as a transparent recording medium with a band that damages the oilless fixing device, the image forming operation is stopped to reliably prevent the failure of the apparatus. it can.

According to the thirteenth aspect, there is provided fixing means for fixing the image on the recording medium in an oilless manner, and the control means identifies the recording medium as an oil fixing recording medium by the identification means. In this case, the image forming operation on the recording medium is stopped. Therefore, when the recording medium is identified as an oil fixing recording medium that damages the oilless fixing device, the image forming operation is stopped to reliably prevent the failure of the apparatus. it can.

According to the fourteenth aspect, the detecting means includes:
Since the band is disposed at a position where at least one band of the banded transparent recording medium can be detected, the banded transparent recording medium can be reliably identified without being erroneously identified regardless of the direction in which the recording medium is conveyed. it can.

According to the fifteenth aspect, since a plurality of the detecting means are provided, it is possible to more accurately detect the registration deviation and to surely detect the type of the recording medium.

According to the sixteenth aspect, the plurality of detecting means are arranged at a position where at least one band of the transparent recording medium with a band can be detected, and most preferably in a direction orthogonal to the conveying direction of the conveying means. Since they are arranged at distant positions, registration deviation can be detected very accurately, and the type of recording medium can be reliably detected.

According to the seventeenth aspect, a plurality of image forming means for forming an image on the recording medium conveyed by the conveying means or the conveying means, and an image shift correction pattern formed by each of the image forming means are read. A control method of the image forming apparatus having a detection unit, wherein the type of the recording medium is identified based on a detection result of the detection unit when the recording medium conveyed by the conveyance unit passes through the detection unit. Since the type of the transfer material can be identified using the registration detection sensor, the number of sensors can be reduced, the apparatus can be easily made compact, and the cost can be reduced.

According to the eighteenth aspect, a recording medium conveyed on the conveying means or a plurality of image forming means for forming an image on the conveying means, and reflected light from the conveying means or the recording medium are detected. Detecting means for detecting a shift of an image formed by each of the image forming means according to a detection result of the detecting means when an image shift correction pattern formed on the transporting means or the recording medium passes through the detecting means; A detecting step of detecting reflected light at the detecting unit when the recording medium conveyed on the conveying unit passes through the detecting unit, wherein the detecting step includes: An identification step of identifying the type of the recording medium based on the detection result of the detection step, so that the detection of the registration mark and the identification of the recording medium are performed using a common sensor. It is possible, a compact it is possible to easily perform the reduction to the equipment number of the sensor, can be realized cost reduction.

Therefore, it is possible to shorten the time required for examining the device design for identifying the type of the recording medium, improve the development efficiency, reduce the number of sensors provided in the device, and realize a cost reduction. This has the advantage that the configuration of the device can be simplified and the device can be easily made compact.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an arrangement of a registration detection sensor and a transfer material identification sensor shown in FIG.

FIG. 2 is a flowchart illustrating an example of a first data processing procedure in the image forming apparatus according to the embodiment.

FIG. 3 is a flowchart illustrating an example of a second data processing procedure in the image forming apparatus according to the embodiment.

4 is a plan view illustrating an example of an arrangement of the registration detection sensor illustrated in FIG.

FIG. 5 is a flowchart illustrating an example of a third data processing procedure in the image forming apparatus according to the embodiment.

FIG. 6 is a schematic sectional view illustrating a configuration of a conventional image forming apparatus.

FIG. 7 is a diagram illustrating an arrangement of a transfer material identification sensor and a registration detection sensor illustrated in FIG. 6;

FIG. 8 is a diagram illustrating a method for identifying a transfer material by the transfer material identification sensor illustrated in FIG. 6;

FIG. 9 is a plan view illustrating the arrangement of bands attached to the OHT with bands.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 2 laser scanner unit 3 developer replenishment unit 4 developing unit 5 transfer roller 6 transfer material transport belt 7 paper feed unit 8 registration detection sensor 9 fixing unit 10, 11 paper discharge unit 12 transfer material identification sensor 13 sensor before registration 100 Controller 101 CPU 102 RAM 103 ROM

Claims (18)

[Claims] A recording medium conveyed by a conveying unit or a plurality of image forming units for forming an image on the conveying unit;
A detection unit for reading an image shift correction pattern formed by each of the image forming units, wherein the detection unit detects when the recording medium conveyed by the conveyance unit passes through the detection unit. An image forming apparatus comprising: an identification unit that identifies a type of the recording medium according to a detection result. 2. An image forming apparatus having a recording medium conveyed on a conveying unit or a plurality of image forming units for forming an image on the conveying unit, wherein reflected light from the conveying unit or the recording medium is detected. Detecting means for detecting the shift of an image formed by each of the image forming means based on the detection result of the detecting means when the image shift correction pattern formed on the transporting means or the recording medium passes through the detecting means. Detecting means for detecting the type of the recording medium based on a detection result of the detecting means when the recording medium conveyed on the conveying means passes through the detecting means. An image forming apparatus comprising: 3. An image forming apparatus according to claim 1, wherein said detecting means is constituted by a reflection type sensor. 4. The image forming apparatus according to claim 1, wherein the identification unit identifies an opaque recording medium and a transparent recording medium according to a detection result of the detection unit. 5. The recording apparatus according to claim 1, wherein the identification unit identifies the opaque recording medium, the transparent recording medium without a band, and the transparent recording medium with a band according to a detection result of the detection unit. Image forming device. 6. The recording apparatus according to claim 1, wherein the identification unit identifies the opaque recording medium, the oil fixing transparent recording medium, and the oilless fixing transparent recording medium in accordance with a detection result of the detection unit. 3. The image forming apparatus according to 2. 7. An image forming apparatus according to claim 1, wherein said conveying means is constituted by a belt. 8. A type detecting means for identifying a type of the recording medium, wherein the identifying means identifies the type of the recording medium according to a detection result of the type detecting means and a detection result of the detecting means. The image forming apparatus according to claim 1, wherein: 9. The image forming apparatus according to claim 8, wherein the identification unit identifies a type of the recording medium that cannot be identified by the type detection unit according to a detection result of the detection unit. 10. The image forming apparatus according to claim 1, further comprising a control unit that controls an image forming operation on the recording medium in accordance with a result of the identification by the identification unit. 11. The control unit stops an image forming operation on the recording medium when the identification unit identifies the type of the recording medium as a type that the image forming unit cannot form an image. The image forming apparatus according to claim 10, wherein: 12. A fixing device for fixing an image on the recording medium in an oil-less manner, wherein the control unit performs the recording when the identification unit identifies the recording medium as a transparent recording medium with a band. The image forming apparatus according to claim 10, wherein the image forming operation on the medium is stopped. 13. A fixing unit for fixing an image on the recording medium in an oilless manner, wherein the control unit performs the recording when the identification unit identifies the recording medium as a recording medium for oil fixing. The image forming apparatus according to claim 10, wherein the image forming operation on the medium is stopped. 14. The image forming apparatus according to claim 1, wherein the detecting unit is disposed at a position where at least one band of the transparent recording medium with a band can be detected. 15. The image forming apparatus according to claim 1, further comprising a plurality of the detection units. 16. The plurality of detecting means are arranged at a position where at least one band of the transparent recording medium with a band can be detected, and are arranged at the farthest position in a direction orthogonal to a conveying direction of the conveying means. The image forming apparatus according to claim 15, wherein: 17. An image comprising: a recording medium conveyed by a conveying unit or a plurality of image forming units for forming an image on the conveying unit; and a detecting unit for reading an image shift correction pattern formed by each of the image forming units. A method for controlling a forming apparatus, comprising: an identification step of identifying a type of the recording medium based on a detection result of the detection unit when the recording medium conveyed by the conveyance unit passes through the detection unit. A method for controlling an image forming apparatus, comprising: 18. A recording medium conveyed on a conveying means or a plurality of image forming means for forming an image on the conveying means,
Detecting means for detecting reflected light from the conveying means or the recording medium, and a detection result of the detecting means when an image shift correction pattern formed on the conveying means or the recording medium passes through the detecting means. And a detecting means for detecting a shift of an image formed by each of the image forming means, wherein when the recording medium conveyed on the conveying means passes through the detecting means, A control method for an image forming apparatus, comprising: a detection step of detecting reflected light by the detection unit; and an identification step of identifying a type of the recording medium based on a detection result of the detection step.