JP3229457B2 - Electrophotographic image forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus for printing an image with dots using an electrophotographic process.

[0002]

2. Description of the Related Art The above-mentioned electrophotographic image forming apparatus forms a toner image in dots on an image carrier such as a photosensitive drum based on image data, and transfers the image to transfer paper. Further, the so-called residual toner adhering to the image carrier even after the transfer is collected by a cleaning device. In such a device, a toner collecting unit is provided in the cleaning device,
Since the waste toner (that is, the above-mentioned collected residual toner) is stored therein, it is necessary to accurately detect the amount of the waste toner.

Conventionally, it has been difficult to accurately and directly detect the amount of waste toner as a means for the detection.
There are many printers that count the number of printed transfer papers and estimate the approximate amount of waste toner based on the counted number. Further, as another detecting means, there is known a means for monitoring the state of accumulation of waste toner in the toner collecting section by using a photo sensor or the like.

However, simply counting the number of transfer sheets as a means for detecting the amount of waste toner as described above,
Toner used for printing on each transfer paper depending on the type of image
Since the amount differs, the amount of waste toner varies for each transfer sheet, and the amount of waste toner cannot be accurately detected. Also, in the detecting means using a photo sensor or the like, the photo sensor is easily contaminated with waste toner or other dust, and it has been difficult to accurately detect the amount of waste toner.

In order to solve the above-mentioned problem, the number of dots of a toner image formed on a photosensitive drum is counted as described in JP-A-62-105180 to discard waste toner. There has been proposed an apparatus that detects the amount of collected wastewater.

FIG. 3 is a schematic configuration diagram of an image forming apparatus that counts the number of dots of the toner image formed on the photosensitive drum and detects the amount of waste toner collected. In FIG. 1, a photosensitive surface 1a of a photosensitive drum 1 serving as an image carrier is shown.
Is charged in advance by the charger 2. The optical writing unit 3 includes a liquid crystal optical shutter 3a and the like, and the recording control unit 4
To perform optical writing with dots on the photosensitive surface 1a to form an electrostatic latent image.

[0007] The electrostatic latent image thus formed is developed by a toner in a developing unit 5 and visualized. Further, the toner image having the dot configuration is transferred by a transfer unit 6 to a paper feeding roll 7.
Is transferred from the cassette 8 and transferred to the transfer paper which is carried in at the same time by the waiting roll 9. After the transfer paper is separated by the separator 10, it is carried out of the apparatus by the paper discharge roll 12 via the fixing device 11. On the other hand, the toner that has not been completely transferred by the transfer unit 6 remains on the photosensitive surface 1a, so that the charge of the toner is neutralized by the neutralizer 13 and the remaining toner is collected by the cleaning unit 14. I do. The collected residual toner is stored as waste toner in a waste toner recovery tank 14a provided in the cleaning unit 14. Thereafter, the charge is removed from the photosensitive surface 1a by the eraser 10, and a uniform charge is applied by the charger 2 in preparation for the next optical writing.

The signal A1 output from the recording control unit 4
Based on the number of dots constituting the image formed in the image forming process described above (hereinafter, referred to as
The number of printed dots is counted, and when a predetermined count is reached, the life signal A2 is sent to the image forming apparatus controller 17.
Is output.

The operation will be described in detail.
When the liquid crystal light shutter 3a is driven, an electrostatic latent image is formed by dots on the photosensitive surface 1a as described above, and the electrostatic latent image is visualized as a toner image by the developing device 5. Thereafter, the toner image is transferred onto the transfer paper supplied from the cassette 8, while a part of the toner image is collected by the cleaning unit 14 as residual toner. In this apparatus, the number of dots printed on an image formed on transfer paper is indicated by a signal A.
By converting to 1 and counting by the counter section 16, the amount of waste toner accumulated in the toner recovery tank 14a in the cleaning section 14 is accurately detected. Upon receiving the life signal A2, the image forming apparatus controller 17 notifies the user that it is time to replace the toner collection tank 14a. As means for this notification, although not shown here, for example, a lamp, a buzzer or the like can be operated, or the image forming process of the apparatus itself can be stopped.

Hereinafter, the basic concept for detecting the amount of waste toner will be described with reference to specific examples. First, the liquid crystal optical shutter 3a is, for example, 240 dots / dot.
When printing at inch resolution, 1 mm
The number of black dots printed per unit is 9.45 dots / mm. Therefore, A4 size transfer paper (210 mm × 297
mm), the number of black dots printed is (210 × 9.45) × ( 297 × 9.45) ≒ 5.
It becomes 570,000. Here, in general printing, it can be estimated that a black printing portion of about 6% of the paper area can be roughly estimated, so that it can be considered that 5.57 million × 0.06 ≒ 334200 black dots are printed on average. It has been experimentally confirmed that the total amount of toner used for this printing is about 45 mg.

In the photosensitive drum 1 set at 23 ° C. and 65 RH, the toner image formed on the photosensitive member surface 1a has a transfer rate of about 80 when it is transferred to transfer paper.
% Has been experimentally confirmed to be about 20%.
% Of the toner is recovered as waste toner in the toner recovery tank 14a. Therefore, in this case, about 9 m
g of toner as waste toner, and the toner recovery tank 14a.
Will be collected.

Here, under the above-mentioned environmental conditions, the toner
Considering the case where the exchange time of the collection tank 14a is set to 10,000 sheets in terms of A4 size transfer paper,
It is sufficient to provide a toner collection tank 14a having a capacity sufficient to collect waste toner of about 10,000 × 9 mg = 90 g at the maximum. Here, the toner-weight-volume ratio is 0.4
g / cubic cm, the capacity of the toner collection tank 14a may be 90 / 0.4 ≒ 225 cubic cm. Also,
The total number of dots printed until the toner collection tank 14a is filled with the collected waste toner is 334 from the above calculation.
200 × 10000 = 3.35 billion. Therefore, the replacement time of the toner collection tank 14a is when the counter unit 16 counts 3.35 billion pieces.

[0013]

In general, however, the relationship between the temperature of the image carrier and the amount of waste toner collected per A4 size transfer sheet is as shown in FIG. Experiments have shown that the amount of waste toner recovered varies depending on the amount of waste toner. More specifically, when the temperature of the image carrier is 23 ° C., the amount of waste toner recovered from about 9 mg per transfer sheet is reduced to about 9.7 mg when the temperature is 10 ° C. and 30 ° C. In the case of the above, each amount is changed to about 8.7 mg. That is, when the temperature is 10 ° C., the total number of printed dots is counted by the counter unit 16 at 3.31 billion, and when the temperature is 30 ° C., the total number of printed dots is 34.7. When the number of waste toner is counted, the amount of collected waste toner reaches 90 g. If the above set value (3.35 billion) is used as it is, if the temperature is 10 ° C., the collected waste toner becomes toner. If the temperature overflows from the recovery tank 14a and is 30 ° C., the toner recovery tank 1
There is a problem that an unused portion occurs in 4a.

The relationship between the humidity of the image carrier and the amount of waste toner collected per sheet of A4 size transfer paper varies with the humidity of the image carrier as is apparent from FIG. Experiments have revealed this. More specifically, when the humidity of the image carrier is 65 RH, the amount of waste toner collected from about 9 mg per transfer sheet is reduced to 15 RH.
To about 9.6 mg in the case of 90 RH and about 8.6 mg in the case of 90 RH.
It fluctuates to 7 mg each. In other words, when the number of dots printed is 15 RH, the total number of dots printed is 3.140 billion by the counter unit 16, and when the number is 90 RH, the total number of dots printed by the counter unit 16 is 3.47 billion. When counted, the waste toner collection amount reaches 90 g. If the above-mentioned set value (3.35 billion pieces) is used as it is, if it is 15 RH, the collected toner becomes the toner collection tank 14a. In the case of 90 RH, there is a problem that an unused portion occurs in the toner collection tank 14a. The purpose of the present invention is to
It is made in view of the actual situation of technology,
Always perform good cleaning regardless of humidity
To provide an electrophotographic image forming apparatus capable of
is there.

[0015]

According to the present invention, in order to achieve the above object, the invention of claim 1 comprises an image carrier,
Process means for forming a toner image by dots on the image carrier and transferring the toner image onto transfer paper; and toner remaining on the image carrier after the transfer of the toner image by the process means. Cleaning means for removing the toner, and toner for recovering the toner removed by the cleaning means.
A recovery tank, a counting means for counting the number of dot images formed by said process means, opposed to said image bearing member, a temperature detecting means for detecting the temperature in the atmosphere of the image carrier table surface vicinity, It is characterized by comprising correction means for correcting the count number counted by the counting means based on the detection result of the temperature detecting means. According to a second aspect of the present invention, there is provided an image carrier, a process means for forming a toner image on the image carrier by dots, and then transferring the toner image onto transfer paper, and a process for transferring the toner image by the process means. Cleaning means for removing toner remaining on the image carrier after the transfer, a toner collection tank for collecting the toner removed by the cleaning means, and an image formed by the process means. counting means for counting the number of dots, facing the image bearing member, a humidity detecting means for detecting the humidity in the atmosphere of the image bearing body surface near the surface, the detection result of said humidity detecting means, by said counting means It is characterized by comprising correction means for correcting the counted number.

[0016]

According to the present invention, there is provided an image carrier, a process for forming a toner image by dots on the image carrier, and then transferring the toner image onto transfer paper. Means for removing toner remaining on the image carrier after transfer of the toner image by the process means.
Cleaning means, a toner collection tank for collecting the toner removed by the cleaning means, a counting means for counting the number of dots of the image formed by the process means, image carrier table surface near
Temperature detecting means for detecting the temperature in the side atmosphere, and correcting means for correcting the count number counted by the counting means based on the detection result of the temperature detecting means, wherein the correction is performed by the correcting means. The amount of toner collected in the toner collection tank is detected based on the count number. According to a second aspect of the present invention, there is provided an image carrier, a process means for forming a toner image on the image carrier by dots, and then transferring the toner image onto transfer paper, and a process for transferring the toner image by the process means. Cleaning means for removing toner remaining on the image carrier after the transfer, a toner collection tank for collecting the toner removed by the cleaning means, and an image formed by the process means. counting means for counting the number of dots, facing the image bearing member, a humidity detecting means for detecting the humidity in the atmosphere of the image bearing body surface near the surface, the detection result of said humidity detecting means, by said counting means Correction means for correcting the counted number, and the amount of toner collected in the toner collection tank is detected based on the number corrected by the correction means.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus showing one embodiment of the present invention. The same members as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, a temperature detecting sensor 19 is provided between the developing device 5 and the transfer device 6 so as to face the photosensitive surface 1a of the photosensitive drum 1. This temperature detection sensor 19
Converts the temperature of the photosensitive surface 1a into a temperature signal C1, and sends the signal C1 to the correction unit 20. Next, the correction unit 20
The dot printing number data D1 sent from the recording control unit 4 is corrected by a preset correction according to the temperature signal C1 to convert the dot printing number signal D1 into a corrected dot printing number. Counting section 16 as data signal D2
Send to

The correction is set by setting the reference environmental conditions when the temperature of the image carrier is 23 ° C. and the humidity is 65%, and when the recording control unit 4 prints 1000 dots for image formation, When the temperature detected by the temperature detection sensor 19 is 10
At ℃, the number of printed dots of 1080
The temperature detection sensor 1
The setting is made such that when the detected temperature of 9 is 30 ° C., the number of printed 970 dots is corrected to be counted by the counting unit 16. A specific method of calculating the correction is to compare the number of dots printed per A4 size transfer sheet by 10
In case of ° C, 360200 ÷ 334200 ≒ 1080 pieces,
In the case of 30 ° C., it is calculated as 232,050 ÷ 334200 ≒ 970. Based on the correction signal D2, the counting unit 16 counts the number of printed dots constituting the image formed in the above-described image forming process,
When a predetermined count is reached, the image forming apparatus controller 1
7, the life signal D3 is output.

Upon receiving the life signal D3, the image forming apparatus control section 17 notifies the user that the time to replace the toner collection tank 14a has come. As this notification means,
Although not shown here, for example, a lamp, a buzzer or the like can be operated, or the image forming process of the apparatus itself can be stopped.

FIG. 2 is a schematic structural view of an image forming apparatus showing another embodiment of the present invention. The same members as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 2, a humidity detecting sensor 21 is provided between the developing device 5 and the transfer device 6 so as to face the photosensitive surface 1a of the photosensitive drum 1. This humidity detection sensor 21
Converts the temperature of the photosensitive surface 1a into a temperature signal E1, and sends the signal E1 to the correction unit 20. Next, the correction unit 20
The dot printing number data signal F1 sent from the recording control unit 4 is corrected by a preset correction according to the humidity signal E1 to convert the dot printing number signal F1 into a corrected dot printing number. Counting section 16 as data signal F2
Send to

The correction is set by setting the reference environmental condition when the temperature of the image carrier is 23 ° C. and the humidity is 65%, and when the recording control unit 4 prints 1000 dots of image formation, When the humidity detected by the humidity detection sensor 21 is 15
In the case of RH, the number of printed dots of 1065 is counted part 1
6 is corrected so that when the temperature detected by the humidity detection sensor 21 is 90 RH, the number of printed 970 dots is corrected to be counted by the counting unit 16. A specific method of calculating the correction is A
Compare the number of dot prints per 4 size transfer paper,
In the case of 15 RH, 3550000 ÷ 334200 ≒ 1
065 pcs, 232050 ÷ 33420 for 90RH
It is calculated as 0 ≒ 970. This counting section 1
6 counts the number of dots printed in the image formed in the above-described image forming process based on the correction signal F2, and outputs a life signal F3 to the image forming apparatus controller 17 when a predetermined count is reached. I do.

Upon receiving the life signal F3, the image forming apparatus control section 17 notifies the user that the time for replacing the toner collection tank 14a has come. As this notification means,
Although not shown here, for example, a lamp, a buzzer or the like can be operated, or the image forming process of the apparatus itself can be stopped.

[0025]

The present invention is as described above. According to a first aspect of the present invention, there is provided an image carrier, and after forming a toner image on the image carrier by dots, the toner image is transferred onto transfer paper. , A cleaning unit for removing toner remaining on the image carrier after the transfer of the toner image by the process unit, and collecting the toner removed by the cleaning unit. A toner collection tank, a counting means for counting the number of dots of an image formed by the process means, and an image carrier surface facing the image carrier.
Temperature detection means for detecting the temperature in the atmosphere near the surface, and correction means for correcting the count number counted by the counting means, based on the detection result of the temperature detection means,
And the amount of toner collected in the toner collection tank is detected based on the count number corrected by the correction means, so that the temperature in the image forming apparatus, that is, the temperature of the image carrier fluctuates. However, the amount of collected waste toner can be accurately detected, and efficient cleaning can be performed. According to claim 2 invention, the image carrier sheet surface in the vicinity
Since the amount of toner collected in the toner collecting tank is detected based on the corrected count number based on the humidity detecting means for detecting the humidity in the atmosphere and the humidity detected by the humidity detecting means, the image forming apparatus Even if the humidity inside the image carrier, that is, the humidity of the image carrier fluctuates, the amount of collected waste toner can be accurately detected, and efficient cleaning can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an overall configuration of an image forming apparatus according to another embodiment of the present invention.

FIG. 3 is a schematic diagram showing the entire configuration of a conventional image forming apparatus.

FIG. 4 is a graph showing the temperature of the image carrier and the amount of waste toner collected per A4 size transfer sheet.

FIG. 5 is a graph showing the humidity of the image carrier and the amount of waste toner collected per A4 size transfer sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Charger 3 Optical writing part 4 Recording control part 5 Developing unit 14 Cleaning part 14a Toner collection tank 16 Counter part 17 Image forming apparatus control part 19 Temperature detection sensor 20 Correction part 21 Humidity detection sensor

Claims (2)

(57) [Claims] 1. An image carrier, a process means for forming a toner image on the image carrier by dots, and then transferring the toner image onto transfer paper, and after the transfer of the toner image by the process means. Cleaning means for removing toner remaining on the image carrier, toner collection tank for collecting toner removed by the cleaning means, and the number of dots of an image formed by the process means. Counting means for counting the image bearing member;
Temperature detection means for detecting the temperature in the atmosphere near the surface, and correction means for correcting the count number counted by the counting means, based on the detection result of the temperature detection means,
Wherein the amount of toner collected in the toner collection tank is detected based on the count number corrected by the correction means. 2. An image carrier, a process means for forming a toner image on the image carrier by dots, and then transferring the toner image onto transfer paper, and after the transfer of the toner image by the process means. Cleaning means for removing toner remaining on the image carrier, toner collection tank for collecting toner removed by the cleaning means, and the number of dots of an image formed by the process means. Counting means for counting the image bearing member;
Humidity detection means for detecting the humidity in the atmosphere near the surface, and correction means for correcting the count number counted by the counting means, based on the detection result of the humidity detection means,
Wherein the amount of toner collected in the toner collection tank is detected based on the count number corrected by the correction means.