JPH11231682A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of obtaining an image having high quality by preventing the erroneous detection of the characteristics of a transfer belt due to soiling in the device and appropriately controlling a process. SOLUTION: As for the image forming device, the device is provided with the transfer belt 103 equipped with plural sensor detection windows (detection part) 6, and the characteristics of the transfer belt 103 are discriminated based on a difference between the detection results of respective sensor detection windows 6 of the transfer belt 103 so as to be reflected in a process control. The characteristics of the transfer belt 103 are integrally decided based on plural detection results.

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 such as a laser beam printer, a copying machine, a facsimile and the like which employs an electrophotographic system.

[0002]

2. Description of the Related Art For example, a color laser printer employing an electrophotographic system is configured as shown in FIG.

FIG. 6 is a cross-sectional view of a conventional color laser printer. In this color laser printer, a recording material conveyed by a roller from a paper cassette 101 transfers a toner image formed on a transfer belt 103. Receiving the fixing device 10
4 is carried.

The toner image on the transfer belt 103 is formed through the following steps.

That is, when a laser beam modulated by an image signal is irradiated onto the photosensitive drum 100 from the scanner unit 107, a latent image is formed on the photosensitive drum 100. The latent image is developed by sequentially switching the developing units Dy, Dm, Dc, and Dk of the respective colors of the developing unit 110, and is visualized as a toner image.

The toner images of the respective colors are sequentially transferred onto the transfer belt 103, and a toner image in which four color toners overlap is formed on the transfer belt 103.

The fixing device 104 has a fixing roller 104a and a pressure roller 104b.
Is heated by a halogen heater from the inside, and the recording material carrying the toner image passes between the fixing roller 104a and the pressing roller 104b, so that the toner image is fixed to the recording material, and the toner image is fixed. The recording material is discharged onto a discharge tray 109 outside the apparatus.

Here, a sensor 5 is provided in the vicinity of the transfer belt 103. The sensor 5 detects a marking on the transfer belt 103, determines an image writing position, and determines the type of the transfer belt 103. Is determined.

[0009]

By the way, the characteristics of the transfer belt vary depending on the manufacturer thereof, and an optimum image can be obtained by changing the transfer conditions and the like according to the characteristics of the transfer belt. The determination of the characteristics of the transfer belt is performed by changing the length in the traveling direction of the light transmitting window formed at the end of the transfer belt.

The light transmitting window is not merely a window for ensuring the strength of the entire transfer belt, but has a light transmitting member embedded therein. For this reason, toner and the like floating in the machine may adhere to the light transmission window and hinder light transmission,
For this reason, the detection pulse width of the sensor may be short.

However, when the manufacturer of the transfer belt is determined based on the pulse width detected by the sensor, the transfer belt may be determined to be short due to dirt despite the fact that the window is originally long. However, there has been a problem that the transfer belt characteristics are erroneously determined.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object thereof is to prevent erroneous detection of the transfer belt characteristics due to dirt in the apparatus and to perform appropriate process control to obtain a high-quality image. An object of the present invention is to provide an image forming apparatus that can be obtained.

[0013]

According to a first aspect of the present invention, there is provided a transfer belt having a plurality of detectors, the transfer belt having a plurality of detectors, and the transfer belt having a different detection result. The characteristic of the transfer belt is comprehensively determined from a plurality of detection results in the image forming apparatus which determines the characteristic of the transfer belt and reflects the characteristic on the process control.

According to a second aspect of the present invention, in the first aspect of the present invention, the detecting section is constituted by a light transmitting window formed on the transfer belt, and the length of the light transmitting window in the belt rotation direction is determined by an optical sensor. , And the most reliable data is selected from the detected data according to the tendency of the detected value to fluctuate due to various conditions, and the characteristics of the transfer belt are determined.

According to a third aspect of the present invention, in the second aspect of the present invention, if the length of the light transmitting window is likely to be short due to the environment inside the machine, the plurality of detected data may be reduced. The characteristic of the transfer belt is determined based on the longest data.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a structural view of a transfer belt portion of an image forming apparatus according to a first embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing a detection waveform of the optical sensor, and FIG. 3 is a flowchart showing a procedure for determining the type of the transfer belt.

In FIG. 1, reference numeral 103 denotes a transfer belt. The transfer power of the motor 3 is transmitted to the belt drive roller 9 by a transmission mechanism 10 to rotate the belt drive roller 9 so that the transfer belt 103 is moved by an arrow 11 shown in FIG. It is driven to rotate in the direction.

The CPU 1 controls the motor 3 and the high-pressure actuator 7 via the motor driver 2 and the HVT driver 4, respectively, and reads the detection information from the transmission type optical sensor 5.

The end of the transfer belt 103 is
One sensor detection window 6 is provided, and the length of each sensor detection window 6 is detected by the optical sensor 5. That is, when the transfer belt 103 is rotationally driven by the motor 3 and the belt detection window 6 sequentially passes through the optical sensor 5, the optical sensor 5 generates a signal having a waveform as shown in FIG.

However, although the lengths of the sensor detection windows 6 are the same, the signal waveform widths t1, t2, t3, and t4 corresponding to the sensor detection windows 6 vary (t3> t).
1>t4> t2), the longest one is selected as correct data. The procedure will be described based on the flowchart shown in FIG.

That is, the lengths of the first to fourth sensor detection windows 6 are respectively detected by the optical sensor 5 and stored as window length data (step 1 to step 4). Is selected (step 5). Next, the value is compared with a window length value (reference value) serving as a reference written on the program (step 6), and the transfer belt 10
3 is determined (step 7), and the result is reflected in the process control (step 8).

In the comparison between the longest window length data and the reference value, an intermediate value of a plurality of window length design values is set as a reference value, and the value of the intermediate value is compared with the longest window length data. Alternatively, if it is larger than the shorter window length design value data, a method of comparing with the next window length may be adopted.

For example, if the type of the transfer belt is A type and B type
If there are two types, and the length of each sensor detection window is designed to be 4 mm and 6 mm, an intermediate value of 5 mm is set as the reference value. The length of the sensor detection window detected by the above method is 4 mm, 5 m
m, 5.5 mm and 6 mm, the longest 6 mm
Is used as the most reliable data and is compared with the reference value of 5 mm, and the transfer belt is determined to be of the B type.

Alternatively, the design value is used as it is as a reference value, and the maximum 6 mm of the detected sensor detection window is 4 mm.
The transfer belt may be determined to be the B type based on the fact that it is larger than mm.

<Embodiment 2> Next, an embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing a procedure for determining the type of the transfer belt.

The basic configuration of the recording apparatus according to the present embodiment is the same as that of the first embodiment. Hereinafter, the procedure for determining the type of the transfer belt will be described with reference to FIG.

First, the length of the first sensor detection window is detected and stored as window length data (step 1), and then the length of the second sensor detection window is detected (step 2). And
By comparing the two data, only the longer one is L1
(Step 3). Subsequently, the length of the third sensor detection window is detected (step 4), the third data is compared with L1, and the longer data is stored as L2 (step 5).

Finally, the length of the fourth sensor detection window is detected (step 6), and the fourth data is compared with L2 to store the longer data as final data (step 7). . Next, the type of the transfer belt is determined by comparing the final data with the reference value (step 8), and the result of the determination is reflected in process control in print control executed later (step 9).

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flowchart showing a procedure for determining the type of the transfer belt.

The basic configuration of the recording apparatus according to this embodiment is the same as that of the first embodiment, and the procedure for determining the type of the transfer belt will be described below with reference to FIG.

First, the length of the first sensor detection window is detected (step 1), and the detected data is compared with the smaller reference value (type A) (step 2). As a result, if the detected data is larger, it is determined that the transfer belt is not of type A. At this time, if there is only type B other than type A, it is immediately determined that the type is type B (step 3). Conversely, if the reference value is larger, the length of the second sensor detection window is detected (step 4), and the detected data is compared with reference A (step 5). This procedure is repeated (steps 6 to 12), and if the last data is also smaller than the reference A, it is determined that the transfer belt is of type A (step 13).

As described above, the present invention does not limit any software procedure. Further, the type of the transfer belt is not limited to two types, and it is easy to determine a larger number of types by setting a plurality of reference values and sequentially comparing the values.

When the detection level tends to increase due to the condition inside the machine, for example, when the sensor detection window tends to increase, it is conceivable to select short data as reliable data.

Further, a method of judging the type of the transfer belt based on the reflectance of the reflective marking using an optical reflection sensor can also be adopted. In this case, taking into account a decrease in the reflectance due to dirt, the above-described embodiment is performed. Data collection and determination may be performed in the same manner by replacing “window length” in the embodiment with “reflection level”.

[0036]

As is apparent from the above description, according to the present invention, a transfer belt having a plurality of detectors is provided, and the characteristics of the transfer belt are determined based on the difference in the detection result of each detector of the transfer belt. In the image forming apparatus, which is to be reflected in the process control, the characteristics of the transfer belt are comprehensively determined from a plurality of detection results, thereby preventing erroneous detection of the characteristics of the transfer belt due to contamination inside the apparatus, High quality images can be obtained by appropriate process control.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a transfer belt unit of an image forming apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a detection waveform of an optical sensor in the image recording device according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a procedure for determining a type of a transfer belt in the image recording apparatus according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a procedure for determining a type of a transfer belt in the image forming apparatus according to Embodiment 2 of the present invention;

FIG. 5 is a flowchart illustrating a procedure for determining a type of a transfer belt in an image forming apparatus according to Embodiment 3 of the present invention.

FIG. 6 is a sectional view of a conventional color laser printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2, 4 Driver 3 Motor 5 Optical sensor 6 Sensor detection window (light transmission window, detection part) 7 High-pressure actuator 9 Belt drive roller 10 Transmission mechanism 103 Transfer belt

Claims (3)

[Claims] 1. An image forming apparatus comprising: a transfer belt having a plurality of detection units, wherein a characteristic of the transfer belt is determined based on a difference in detection result of each detection unit of the transfer belt and reflected in process control. An image forming apparatus, wherein characteristics of a transfer belt are comprehensively determined from a plurality of detection results. 2. The apparatus according to claim 1, wherein the detecting unit includes a light transmitting window formed in the transfer belt, and a length of the light transmitting window in a belt rotation direction is detected by an optical sensor. 2. The image forming apparatus according to claim 1, wherein the most reliable data is selected according to the tendency of the fluctuation, and the characteristics of the transfer belt are determined. 3. When there is a possibility that the length of the light transmitting window is detected to be short due to the environment inside the apparatus, the characteristic of the transfer belt is determined based on the longest data among the plurality of detected data. Characteristic image forming apparatus.