JPS58221858A - Method for stabilizing image of recording device - Google Patents

Abstract

PURPOSE:To stabiize an image, by forming 3 kinds of charge pattern regions of a noncharged part, a nonexposed part, and an exposed part on a photoreceptor, and obtaining information on a suitable or nonsuitable state with respect to each factor of developer, charging potential, and exposure condition using one detector. CONSTITUTION:Three regions of a noncharged part A, a nonexposed part B, and an exposed part C are set so as to pass through the region to be detected with a detection unit in accordance with rotation of a photosensitive drum, and when an image model is formed in suitable conditions, density is high in the noncharged part A, density is absent in the unexposed part B, and density is somewhat lower in the exposed part C than A. When the reflection density of the part A does not reach the reference level, developer or toner is replenished, agitation of the developer, destaticization of the photoreceptor, cleaning function, etc. are checked, and adjusted. When it reaches the reference level within the repetition times of these checks and adjustments, the next nonexposed prt B is checked, and when it does not reach the reference level, output of a corona charger is adjusted, functions of destaticization of the photoreceptor and its cleaning are checked and adjusted. Likewise, the exposed part C is checked, and when the part C does not reach the reference level, besides the check and adjustment of destaticization and cleaning functions, adjustment of exposure is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image stabilization method for a recording device.

After uniformly charging the photoreceptor, it is exposed to light containing image information,
In a recording apparatus that obtains a recorded image by visualizing the electrostatic latent image resulting from the exposure with toner charged with a predetermined polarity and transferring and fixing the visible image onto transfer paper, a so-called electrophotographic method is used. The following methods are conventionally known as image stabilization means.

For example, (a) Adjustment and setting of the charging position and exposure conditions by detecting the photoconductor surface potential, (b) Adjustment and setting of developer appropriate conditions by detecting developer characteristics, 1-1° photoconductor surface adjustment. This method mainly involves adjusting and setting the developer conditions by detecting the image reflection density and knowing whether the image is suitable or not. However, in each of the above methods (a) to (c), the detection means and the adjustment target are in one-to-one correspondence, resulting in complicated component configurations and cannot meet the demands for miniaturization and simplification. ℃
・.

The present invention has been made with attention to the above problem, and it is possible to know whether the developer, charge level, and exposure conditions are appropriate or inappropriate using a detection means, thereby stabilizing the image. An object of the present invention is to provide an image stabilization method for a recording device.

Hereinafter, the present invention will be explained in detail with reference to examples.

In the image stabilization method of a recording device according to the present invention, five types of charge pattern areas, ie, an uncharged part, a non-image exposed part, and an image exposed part, are specified on a photoconductor, and the five types of charge pattern areas are A developing step for commonly developing the photosensitive surface reflection density and a reflection density detection step for commonly detecting the photosensitive surface reflection densities of the five types of charge pattern areas are sequentially performed to determine the actual reflection density that appears in each of the five types of charge pattern areas. The present invention is characterized in that the optimum image forming conditions are set by comparing and adjusting the reference reflection density corresponding to a desired desired proper recorded image state set in advance.

As an embodiment of the present invention, first, it is applied to a type of recording device that uses an LED array as an exposure light source, and a negative electrostatic latent image obtained by negative image exposure is reversely developed to become a positive image, and then transferred to transfer paper. Explain an example.

In FIG. 1, reference numeral 1 indicates a photosensitive tram, around which the following process members are arranged in the order of rotation direction in the direction of the arrow.

First, reference numeral 2 indicates a corona charger, and the (
+) side is connected. During recording, the photoreceptor is uniformly charged by the corona charger 2.

Reference numeral 4 indicates a lens that images the light from the LED array 5 onto the photoreceptor. A negative electrostatic latent image is formed by erasing the portion corresponding to the line portion.

Reference numeral 7 indicates the developing unit, and the toner T in the hopper 8
The toner particles fall into the casing 12 via the replenishment mechanism 9, are agitated by the agitator side 10, are adsorbed by the developing roller 1, and are supplied onto the photoreceptor. Then, the toner T is electrostatically attracted to the exposed portion of the photoreceptor, and a positive image is visualized.

Reference numeral 15 denotes a corona charger for transfer, which charges the transfer paper S fed from the paper feed table 14 via the paper feed rollers 15 and the conveyance rollers 6 from the back side to generate the visualized positive image. The image is transferred onto the transfer paper S.

Reference numeral 17 denotes a corona charger for separation, which charges the transfer paper from the back side and electrostatically separates it from the photoreceptor. The thus separated transfer paper is sent to the fixing device 19 via the conveyor belt 18, where it is fixed while passing through this section, and sent out to the tray 21 by the discharge roller 2o.

Reference numeral 22 denotes a charge removal lamp, which removes the charge on the photoreceptor which has been transferred through the above process.

Reference numeral 25 indicates a cleaning unit, which removes toner remaining on the photoreceptor after the static electricity has been removed.

The above is the configuration and image creation process of a general recording device. In carrying out the present invention, the recording device includes a developing unit 7 and a transfer corona charger 15 in the rotation direction of the photoreceptor drum 51. A detection unit 24 for detecting the reflection density of the photosensitive surface is provided between the photosensitive surface and the photosensitive surface.

This detection unit 24 includes a light emitting section 25 and a light receiving section 26. In addition, when carrying out the present invention, the photoreceptor is particularly equipped with the following:
Five areas, namely, an uncharged area, a non-image exposed area, and an image exposed area, are locally designated and provided, and these five areas pass through the detection area of the detection unit 24 in response to 10 rotations of the photoreceptor drum. The location is determined.

Incidentally, if these five areas are schematically shown, they are rectangular areas as shown in Fig. 2, where the non-charged area is indicated by A, the non-exposed area is indicated by 8, and the image exposed area is indicated by C. .

Now, the image stabilization method according to the present invention is as follows:
After the main switch of the recording apparatus is turned on, before the above-described general image creation, or after a predetermined number of images have been created, the following procedure is performed.

As described above, a surface potential pattern of the uncharged area A, the unexposed area 8, and the image exposed area C is formed on the photoreceptor corresponding to the detection area by the detection unit 24, as shown by the broken line in FIG. These are developed in the developing unit 7 while applying the illustrated developing bias.

The image model when all of these areas are in a proper state is shown in Figure 2, where the uncharged area A is sufficiently developed and has a high density, and the unexposed area B is not developed and therefore has no density. The image-exposed area C shows a density that is somewhat lower or sufficiently higher than that of the uncharged area.

The density level of each charge pattern when it is in a proper state is set in advance as the reference level of the reference reflection density corresponding to a desired proper recorded image state, and when checking, the detection unit 24 performs the check. The image is stabilized by comparing the actual reflection density under the current conditions with the reference reflection density and adjusting each part.

The order is that after forming a potential pattern and performing development, it is first compared whether the reflection density level in the uncharged area A is at the reference reflection density level, and thereby it is determined that the developer is in a proper state. Determine whether or not. If the reference level is maintained, the process proceeds to the next determination step regarding the non-exposed area B. However, if the standard level is not reached,
This means that the toner is in an inappropriate state, so take countermeasures. For example, in the case of a -component type developer, a developer is added, and in the case of a two-component type developer, a toner is added.

Then, it is checked whether the developer stirring function is normal and whether the static electricity removal and cleaning of the photoreceptor are being performed normally, and if any abnormalities are found, adjustments are made. Then, a potential pattern is formed again, development is performed, and reflection density is detected. and.

If the standard level is not reached, repeat the above steps until the specified number of repetitions is reached. If the reference level is not reached even after a predetermined number of repetitions, it is assumed that there is some other abnormality, and a warning is displayed and the operation of the recording device is stopped to prevent the creation of abnormal images.

On the other hand, if the reference level is reached within the prescribed number of repetitions, the process proceeds to the next determination step for the non-exposed area B.

The check on the unexposed area is performed to determine whether the charged potential is in an appropriate state.
The procedure is almost the same as the judgment for non-charged parts, but the difference is that if the reference level has not been reached, the output of corona charger 2 is adjusted as a countermeasure. The point is to do it. in particular,
This is done by adjusting the DC variable power supply 5.

In addition, check and adjust whether the photoconductor static electricity is removed properly and check and adjust the photoconductor cleaning function 2.
The steps are the same.

If the reference level is reached within the prescribed number of repetitions or if the reference level is reached from the beginning, the process proceeds to the next determination step for the image exposure section C.

This judgment for the image exposure area C is performed to check whether the post-exposure potential is appropriate, that is, whether the exposure amount is good (whether there is a decrease in the light amount due to light source deterioration, optical system dirt, etc.). , is not at the standard level, in addition to checking and adjusting whether the photoconductor static electricity is removed properly and checking and adjusting the photoconductor cleaning function,
Adjust the exposure amount. The exposure amount is adjusted by increasing the current applied to the LED array 5 as a light source, increasing the exposure time, etc., and is performed by adjusting the output of the image information source 6.

-1 When it is determined that the reflection density of all areas of the uncharged area A, the unexposed area B, and the image exposed area C is maintained at the reference level, the recording device sets the conditions for creating an appropriate image. It means that it has been arranged.

In addition to the above-mentioned factors, fatigue of the photoreceptor may also be considered as a factor that causes the non-exposed area 8 and the image exposed area C to differ from the reference level. If this photoreceptor is fatigued,
In particular, when the life is close to the end, adjustment using other adjustment elements cannot be achieved, so it is necessary to set appropriate upper limits for the output of the corona charger 2 and the adjustment lJ of the exposure amount.

FIG. 4 expresses the above explanation in an easy-to-understand manner as a flowchart.

As described above, according to the present invention, various factors that hinder image stabilization can be checked with one detection unit 24.

Although the above-mentioned embodiments relate to recording apparatuses that form a negative electrostatic latent image on a photoreceptor, the present invention is not limited thereto, and can be carried out using ordinary electrophotographic apparatuses and the like.

It can also be carried out in a recording device that forms a positive electrostatic latent image on a photoreceptor, which is currently used.
Five types of charge patterns are formed on the photosensitive member C, including an uncharged area A', an unexposed area B', and an exposed area C', and these are combined into one detection unit similar to the detection unit 24 in the embodiment described above. The reflection density is determined by the following.

For example, regarding the uncharged area A', under appropriate conditions, this area is a toner non-adherent area, and if the level is higher than the reference level, it indicates that toner is adhering, and the causes include: This means that either the toner concentration is abnormally high or that toner charged to the opposite polarity is mixed into the developing unit, so appropriate measures should be taken to eliminate these problems.

As in the embodiment described above, if there is no abnormality in the determination regarding the uncharged area A', determination is made regarding the unexposed area B'. This non-exposed area corresponds to the drawing area of the image, and under appropriate conditions, is a so-called solid black area. If it is lower than the reference level, it is likely that the photoreceptor potential is too low. If there is no abnormality in the photoreceptor potential,
It is determined that the concentration of the developer is lower than a predetermined level, and an adjustment is performed by a degree.

If there is no abnormality in the determination at the non-exposed section B, the determination at the exposed section C is performed. The exposed portion d corresponds to the background portion of the image, and is a portion to which toner should not adhere under proper conditions. If it is lower than the reference level, it means that some toner is being deposited, so the cause may be an insufficient amount of exposure light, and the countermeasure is to increase the light amount of the light source.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating an example of a recording apparatus suitable for implementing the present invention, FIG. 2 is an explanatory diagram of charge patterns formed when implementing the present invention, and FIG. 5 is a diagram illustrating the surface potential of each charge pattern. A diagram explaining the mutual relationship and development bias level,
FIG. 4 is a diagram illustrating the method 1 of image stabilization according to the present invention. 1... Photosensitive drum, 24... Detection unit, A.
...-uncharged area, B...unexposed area, C...image exposed area. Agent Karasuo Kabayama J So-called Uzu drawing procedure amendment (voluntary) December 1980 Mi Director General of the Japan Patent Office Wakasugi Oro (Patent Office Examiner) 1 Indication of the case 1988 Patent Application No. No. 104878 No. 2 Name of the invention Image stabilization method for recording device 3 Related to the case of the person making the amendment F-related patent (B Junto Address 1-3-6 Nakamagome, Ota-ku, Tokyo Name)
Name (674) Rico Co., Ltd. -4
Agent address: 156 Address: 2-6-28-5 Sakuragaoka, Setagaya-ku, Tokyo
Target of amendment: The "Claims,""Detailed Description of the Invention," and "Brief Description of the Drawings" columns of the specification. 6. Details of the amendment (1) “Scope of Claims” are as shown in the attached sheet. "Here, for example, when the reflection density is high, it corresponds to a case where there is a large amount of toner adhesion, and when the reflection loss is low, it corresponds to a case where the amount of toner adhesion is small. The same applies in the following explanation." ( b) “Non-image exposure area” in page 6, line 6
"L non-exposed part" and "image exposed part" to 1 exposed part - 1v?
−. Change each. (4) At the end of the same No. 500, "non-image exposure area" is changed to "non-exposed area" and "image exposure" is changed to "exposure". [51, page 6, line 7 and the tumor image in line i6 from the bottom] are deleted.
1(6) Delete "Image" in the first line of page 7. (71, 7th row, 5th line and ] to 7th line, 1st standard level in the 5th row from the bottom) are respectively changed to ``standard value level.'' (81, 700th line, 11th line and "Level" in line 12
Delete each. 0) Page 8, lines 5, 7, and 11. Add [value - 1] next to "criterion" in the fourth row from the bottom. 00) "1 standard level" in the 5th and 6th lines of the same page 9, and the 8th line of the lower blade) was changed to "standard value level" □ 01) "1 standard level" in the last line of the same page 9 Delete image-1.
``kr standard value level''. 031 Delete "1 image in the 4th line of page 1U". 04) Same gP, page 11, line 8, line 6 from the bottom, ``standard snoring level'' was changed to ``standard value level.''09
Same @ page 12, line 8146 σ) Replace "B" with "B'" 0 翰 Same @ page 12, line 184 [c -1'i r' C
''' VC replacement. Ru. +171 "Reference level" in the 7th line of page 6 has been changed to "reference value level" and "low" to "F high". Side ``Delete image j'' in line 2 from 1201 of the same document. After uniformly charging the photoreceptor in the desired area, glazing the photoreceptor with light containing image information, and then In a recording device that obtains a recorded image by visualizing an electrostatic accumulated image by toner charged with a predetermined polarity and transferring and fixing the visible image to a transfer paper, an uncharged 1 is placed on a photoreceptor. A developing step in which six types of charge pattern areas are set, a portion, a non-exposed area, and an exposed area, and the three types of charge pattern areas are developed in common, and the photosensitive surface reflection density of the six types of charge pattern areas is determined. A reflection detection process is sequentially performed to commonly detect reflection, and the actual reflection density that appears in each of the charge pattern areas of the type B is compared with a reference reflection density that corresponds to a preset desired appropriate recorded image condition. A method for stabilizing an image of a recording device, the characteristic of which is to adjust the optimum image forming conditions by adjusting the image forming conditions.

Claims (1)

[Claims] After uniformly charging a photoreceptor, exposing it to light containing image information,
In a recording device that obtains a recorded image by visualizing the electrostatic latent image resulting from the exposure using toner charged with a predetermined polarity, and transferring and fixing the visible image onto transfer paper, 5: non-charging section, non-image exposure section, image exposure section
A developing process in which each type of charge pattern/area is specified and the corresponding types of charge pattern areas are developed in common, and a reflection density detection process in which one photosensitive surface reflection of the five types of charge pattern areas is commonly detected is carried out. The optimum image is created by sequentially comparing and adjusting the actual reflection densities that appear in each of the five charge pattern areas with a preset reference reflection density that corresponds to a desired and appropriate recorded image state. An image stabilization method for a recording device, characterized by setting formation conditions.