JP3361929B2 - Electrophotographic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an electrophotographic apparatus for forming an image with toner from a toner cartridge removably attached to a developing unit. 2. Description of the Related Art In recent electrophotographic apparatuses such as copying machines,
To the electrostatic latent image formed on the photoconductor, a one-component toner is supplied from a toner cartridge detachably attached to a developing unit, and the electrostatic latent image is developed into a toner image. The image is transferred onto a transfer sheet and subjected to a fixing process to form an image. In this case, if only one-component toner is supplied from the toner cartridge to the developing unit, the concentration of the additive in the toner used for development in the developing unit increases with time, and The resulting image density is reduced. In order to solve this problem, the same applicant as the present invention circulates the toner between the toner cartridge and the toner storage section of the developing section, so that the toner used for development in the developing section is A developing device for preventing an increase in the concentration of additives in the toner has been proposed by a patent application filed on April 28, 1995. However, in the developing device according to the proposal, when the device is stopped at the time of toner end and the toner cartridge is replaced, the toner having a high additive concentration is supplied to the developing section immediately before the replacement. Each time the toner cartridge is replaced repeatedly, the concentration of the toner additive remaining in the developing section increases, which adversely affects image formation. SUMMARY OF THE INVENTION The present invention has been made in view of the current situation of the increase in the concentration of additives in toner in the developing section of an electrophotographic apparatus as described above. An object of the present invention is to provide an electrophotographic apparatus capable of removing an adverse effect of an increase in the concentration of a substance. [0007] To achieve the above object, the present invention provides a developing unit for developing an electrostatic latent image into a toner image.
And a one-component toner detachably attached to the developing unit.
A toner cartridge for supplying the toner to the developing unit;
Between the toner container of the developing unit and the toner cartridge
Toner circulating means for circulating toner by
Toner end sensor that detects toner deficiency in the cartridge
A driving unit for driving only the toner circulation unit.
Having. In the present invention, the driving means includes
Toner end sensor detected by toner end sensor
As a result, the drive of other means including the developing unit is stopped.
From that time until the preset time elapses
During this time, the toner circulating means is driven . For reference, there is also a configuration in which a position where the toner is collected by the toner circulating means into the toner cartridge is provided outside the effective image width . An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory view showing a configuration of a main part of the present embodiment, FIG. 2 is a perspective view showing a configuration of a toner cartridge portion in FIG. 1, and FIG. 3 is a perspective view showing a configuration of a supply member portion in FIG. 4 is an explanatory diagram showing the overall configuration of the present embodiment, FIG. 5 is a flowchart showing a first operation of the present embodiment, and FIG. 6 is a flowchart showing a second operation of the present embodiment. In this embodiment, as shown in FIG. 4, a paper cassette 20 containing transfer paper P is detachably attached to a lower portion of a housing 41 containing an image forming section D. A paper discharge tray 45 is formed on the upper surface of the housing 41, and a paper discharge stopper 46 is attached to the paper discharge tray 45 in the direction of arrow b in FIG. The exterior part 6 on the front of the housing 41
An operation panel 60 is provided at an upper portion of the projection 5. A paper feed tray 50 is attached to the lower part of the exterior 65 so as to be rotatable around the pins 51 in the direction θ in FIG.
1 is rotated clockwise around the center 1 and is positioned substantially at right angles to the front surface of the housing 41. When not in use, it is turned counterclockwise around the pin 51 and attracts and contacts the front surface of the housing 41 with a magnet. It is configured as follows. An intermediate plate 22 on which the transfer paper P is placed is provided in the paper cassette 20. The intermediate plate 2 is moved by an arm 21 to which a spring force (not shown) is applied.
2 is biased upward, and the uppermost transfer sheet of the transfer sheet P is pressed against the sheet feed roller 24 disposed in the housing 41 near the end of the sheet cassette 20. The paper feed tray 50 is provided with a middle plate 53 on which the transfer paper P is placed. The middle plate 53 is biased upward by a spring 52, and the uppermost transfer paper P is
It is pressed against a paper feed roller 54 provided with a pin 51 at the center. On the other hand, a photoreceptor 1 is disposed in a housing 41 so as to be rotatable about an axis. The photoreceptor 1 is irradiated with a laser beam modulated by an image to be formed, 1
A laser optical system 3 for forming an electrostatic latent image of an image to be formed on the peripheral surface of the housing 41 is provided over the bottom of the housing 41 and near one side. An electrostatic latent image formed on the photoconductor 1 is toner-adjacent to the incident position of the laser beam from the laser optical system 3 in a counterclockwise direction and close to the peripheral surface of the photoconductor 1. A developing unit 5 for developing an image is provided, and a transfer unit 7 for transferring the toner image formed on the photoreceptor 1 to the transfer paper P is provided adjacent to the developing unit 5 in a counterclockwise direction. I have. A fixing roller 32 having a heater 31 is provided above the housing 41 in the vicinity of the transfer unit 7.
And a pressure roller 33, and a fixing unit 8 for fixing the transfer paper P on which the toner image has been transferred is arranged and provided.
5, an opening 41a is formed, and the opening 41a is formed.
Is provided with a paper discharge roller 40. At a side end of the housing 41 adjacent to the laser optical system 3, a case 72 accommodating electric and control components such as a power supply 70 and a printed board 75 is disposed. Is provided with a case 82 accommodating a controller board 80 for controlling the entire operation. FIG. 1A is an explanatory view showing the structure of a main part of the present embodiment, and FIG. 1B is a structure at both ends of a portion where a toner cartridge and a developing device are opposed to each other in FIG. FIG. 3C is an explanatory view showing a configuration at a central position of an opposing portion of the toner cartridge and the developing device in FIG. The developing unit 5 of the present embodiment is similar to that of FIG.
As shown in FIG.
The toner cartridge 60 in which the toner is stored is detachably mounted. In the toner cartridge 60, a stirring and replenishing member 63 for stirring and replenishing the magnetic toner 64 is provided. As shown in FIG. Cartridge 60
At one end, a supply port 60a for supplying the magnetic toner 64 to the developing device 4 is provided at a central position, and a collecting port 60 for collecting the magnetic toner 64 from the developing device 4 is provided at both end positions.
b, and these recovery ports 60b are provided outside the image effective width L. Also, the developing unit 5
Is provided with a toner end sensor that detects a toner deficiency state in the toner cartridge 60 and outputs a detection signal. Further, in the toner cartridge 60, as shown in FIG. 1A, a magnet roller 61 is provided along the vicinity of the supply port 60a and the recovery port 60b, and one edge of the supply port 60a. As shown in FIG. 3C, a protrusion 65 is formed to project the magnetic toner 64 from the magnet roller 61 and supply it to the developing device 4. As shown in (b), the collected magnetic toner 64 is applied to the magnet roller 6.
A scraping member 62 for scraping from 1 is attached. On the other hand, in the developing device 4, an opening groove 4a is formed at a position facing the supply port 60a and the recovery port 60b when the developing device 4 is attached to the toner cartridge 60, and an opening groove facing the recovery port 60b. 4a toner cartridge 60
An elastic member 16 formed of a film material or the like for guiding the collection of the magnetic toner 64 is attached to an edge portion in the center direction of. In addition, in the developing device 4, as shown in FIG. 3, a replenishing member 14 is provided to extend toward the opening groove 4a.
An logger 15 is wound around the supply member 14. Further, a developing roller 13 is provided in the developing device 4.
An intermediate roller 12 that is in contact with the developing roller 13 is provided,
The intermediate roller 12 is disposed in contact with the photoreceptor 1, and the developing roller 13 is provided with a thin layer blade 36 for keeping the thickness of the magnetic toner 64 held constant. In the present embodiment, the auger 15 and the magnet roller 61 are configured to be driven independently of other driving units. The operation of this embodiment having such a configuration will be described. The original image is optically read by a scanner (not shown), and a laser beam modulated by the original image is obtained. This laser beam is applied to the peripheral surface of the photoconductor 1 rotating counterclockwise to scan the original image. Irradiated correspondingly, an electrostatic latent image of a document image is formed on the peripheral surface of the photoconductor 1. With respect to the electrostatic latent image formed on the photoconductor 1, the rotation of the photoconductor 1 causes the toner cartridge 60 of the developing unit 5 to rotate.
The magnetic toner 64 supplied to the developing device 4 from the developing device 4
Of the photosensitive member 1 via the developing roller 13 and the intermediate roller 12
And the electrostatic latent image on the photoconductor 1 is developed into a toner image. In this case, the magnetic toner 64 in the toner cartridge 60 is sent out toward the magnet roller 61 by the stirring / supplying member 63 and
By the magnetic force of 1, the magnetic roller 61 is held on the magnet roller 61, is scraped off by the convex portion 65 with the rotation of the magnet roller 61, and is supplied into the developing device 4 through the opening 60 a and the groove opening 4 a. Then, the magnetic toner supplied to the developing device 4 is sent in the direction of arrow A in FIG. 3 to be supplied to the developing roller 13, formed into a uniform toner layer by the thin layer blade 36, and held by the intermediate roller 12. , From the intermediate roller 12 to the photosensitive member 1. The transfer paper P is transferred from the paper cassette 20 or the paper feed tray 50 to the transfer unit 7 in synchronization with the position of the toner image formed on the peripheral surface of the photosensitive member 1 reaching the position of the transfer unit 7. Supplied. When the paper cassette 20 is used, the uppermost transfer paper P placed on the middle plate 22 of the paper cassette 20 is picked up by the paper feed roller 24, and is transferred to the photoconductor 1 via the registration roller 25. It is sent so as to be sandwiched by the transfer unit 7.
When the paper feed tray 50 is used, the uppermost transfer paper P placed on the middle plate 53 of the paper feed tray 50 is picked up by the paper feed roller 54, It is fed so as to be sandwiched between the photoconductor 1 and the transfer unit 7. In this way, the transfer unit 7 transfers the toner image on the peripheral surface of the photoreceptor 1 to the transfer paper P sent to the transfer unit 7, and the transfer paper on which the toner image has been transferred. P is transported to the fixing unit 8,
The transfer paper P is applied to the fixing roller 32 heated by the heater 31.
The transfer paper P is pressed in a heated state by the pressure roller 33.
The toner image is fixed on the transfer paper P, and the image of the original image is formed on the transfer paper P. The transfer paper P on which the image has been formed in this manner is discharged by the discharge paper stopper 4 by the discharge roller 40.
6 is discharged onto the discharge tray 45 moved according to the size of the transfer paper P. In this embodiment, the toner cartridge 60
The toner circulating operation performed with the replacement will be described with reference to the flowcharts of FIGS. In the present embodiment, when the above-described image recording operation is performed in step S1 of FIG. 5, the toner end sensor starts operating. In step S2, the magnetic toner 64 in the toner cartridge 60 is detected by the toner end sensor. When the stored amount of the toner falls below the preset lower limit reference value and the toner deficiency state is detected, the process proceeds to step S3, in which the auger 15 and the magnet roller 61 start to be driven. The display of the toner end is performed, and the process proceeds to step S5 to stop the operation of the other driving units other than the auger 15 and the magnet roller 61. The driving of the auger 15 and the magnet roller 61 is continued for a predetermined time set in advance, and the magnetic toner 64 having a high additive concentration in the developing device 4 is transported in the direction shown by the arrow B in FIG. As shown by arrow C, the elastic body 16 feeds the toner into the toner cartridge 60 through the opening groove 4a and the recovery port 60b,
And is scraped off by the scraping member 62 by the rotation of the magnet roller 61 and collected by the toner cartridge 60. When a predetermined time has elapsed, the drive of the auger 15 and the magnet roller 61 is stopped, and then the toner cartridge 60 in a toner-deficient state is removed from the developing device 4 and a new toner cartridge 60 filled with toner is removed. It is attached to the developing device 4. As described above, according to the present embodiment, the toner
-End sensor is out of toner in toner cartridge 60
When the state is detected, the auger 15 and the magnet roller 6
Since the other drive units of the apparatus are stopped, except for 1,
The magnetic toner 64 having a high additive concentration in the container 4
5 and the magnet roller 61 are driven for a predetermined time.
Then, the toner is collected in the toner cartridge 60. For this reason, according to the present embodiment, the additive concentration of the magnetic toner 46 of the developing device 4 is reduced by the toner cartridge.
Image density is increased each time the cartridge 60 is replaced, and the image density formed is reduced.
If the collection port 60b is provided outside the effective image width L as a reference , it is possible to perform image formation at a stable image density .
The state in which the toner is collected does not directly affect the image density, and the image can be formed with a stable image density even if the collection is incomplete. According to the present invention, the driving means includes
Toner shortage is detected by toner end sensor
As a result, the driving of the other units including the developing unit is stopped.
From that time until the preset time elapses
During, since driving the toner circulating means, Tonaka
Before replacing the cartridge, set the high additive concentration
Toner is recovered, increased additive concentration in the toner in the developing unit at every replacement of the toner cartridge, the image density to be formed is prevented from being lowered, always possible to perform a stable image density in the image forming become. [0035] [0036] For reference, in addition to the effects obtained by the invention, the recovery position of the toner to the toner cartridge by the toner circulating means, if provided outside the image effective width
If the toner collection status does not directly affect the image density,
Image formation can be performed with a stable image density.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a configuration of a main part of an embodiment of the present invention. FIG. 2 is a perspective view showing a configuration of a toner cartridge part of FIG. 1; FIG. 3 is a perspective view showing a configuration of a replenishing member of FIG. 1; FIG. 4 is an explanatory diagram showing an overall configuration of the embodiment. FIG. 5 is a flowchart showing a first operation of the embodiment. [Description of Signs] 1 Photoconductor 4 Developing unit 5 Developing unit 14 Replenishing member 15 Auger 16 Elastic body 36 Thin layer blade 60 Toner cartridge 60a Supply port 60b Collection port 61 Magnet roller 62 Scraping member 63 Stirring / supplying member

Claims (1)

(57) [Claim 1] A developing section for developing an electrostatic latent image into a toner image
And a one-component toner detachably attached to the developing unit.
A toner cartridge to be supplied to the developing unit, a toner container of the developing unit, and the toner cartridge.
A toner circulating means for circulating toner between the toner cartridge and a toner circulating means for detecting a toner deficiency state of the toner cartridge;
Only the toner end sensor and the toner circulating means.
Driving means, and the driving means is provided with a toner end sensor.
-When a deficiency condition is detected, other
Even if the drive of the stage is stopped, a preset time from that point
Until the time elapses, the toner circulating means is driven.
Electrophotographic apparatus, characterized in that that.