JPH08166714A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device which correctly detects an amount of remaining developer. CONSTITUTION: A sensor guide 21 is provided parallel to the side wall 10a1 of a toner storage container, and when a disk 23 makes one rotation in synchronism with the feeding of recording paper, a sensor holder 22 fitted to an eccentric boss 23a is alternately moved upward and downward one time along the guide 21. In this case, since a part of the holder 22 passes the detecting part of a photointerruptor 24, the reference position of a magnetic bridge sensor 20 is recognized. Also, when the sensor 20 reaches a boundary between the presence and absence of toner by the movement of the holder 22, the detecting signal of the sensor 20 suddenly changes and detects the presence or absence of the toner. That is, the amount of remaining toner is calculated by calculating a time difference Δt from the start of the detecting operation of the sensor 20 to the detection of toner emptiness accompanying the sudden change of the detecting signal, and it is converted into the height of the remaining toner.

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 having a function of recording image information by using a developer and detecting the presence or absence of the developer or the remaining amount of the developer in a printer, a copying machine, a facsimile or the like. is there.

[0002]

2. Description of the Related Art Conventionally, as a developer presence / absence detection device in an electrophotographic apparatus or the like, a light transmission type device for detecting the presence / absence of a developer between a light source and a light receiving element is provided so as to form a photo interrupter. A developer presence / absence detecting device is known.

FIG. 7 shows a conventional example of a light transmission type developer presence / absence detecting device. In the figure, 101 is a light emitting element, and 102 is a light receiving element. Reference numeral 103 denotes a developer container, which is the light emitting element 1 described above.
01 and the light receiving element 102 are provided with windows 104 and 105 for transmitting light.

In this apparatus, the developer storage container 103
While the developer is sufficiently inside, the light of the light emitting element 101 entering the developer container 103 through the window 104 is blocked by the developer and does not reach the light receiving element 102. On the other hand, when the developer accommodating container 103 becomes empty due to the consumption of the developer, the light of the light emitting element 101 reaches the light receiving element 102 through the windows 104 and 105. In this way, the presence or absence of the developer is detected by the change in the output of the light receiving element 102.

Reference numeral 106 is a window cleaning member, which is rotated by a drive source (not shown) with the rotating shaft 107 as the center of rotation. Reference numeral 108 denotes a cleaning sheet made of a flexible material. The cleaning sheet 108 rotates with the rotation of the window cleaning member 106.
5 and the cleaning sheet 108 contacts the windows 104, 10
The developer attached to the inner surface of No. 5 is wiped off. This prevents light from the light emitting element 101 from being blocked by the developer adhering to the window even when the developer storage container 103 is empty, and prevents the developer from being determined to be present.

[0006]

However, in the above-mentioned conventional example, the output of the light receiving element is not obtained linearly with respect to the consumption amount of the developer, and the output changes abruptly at a certain consumption amount. The amount of the remaining developer (consumption amount) is limited to detecting the presence or absence of the developer.
Has the drawback that it is difficult to detect. Therefore, it is necessary to inform the user that the developer has run out suddenly, which is not kind.

Further, since the detection position is constant depending on the positions of the light emitting element and the light receiving element, there is a drawback in that the difference in the amount of developer consumed depending on the location cannot be detected.

Further, it is necessary to provide the window cleaning member in the developer accommodating container, which complicates the mechanism in the developing container, and
There is a drawback in that the developer may move abnormally due to load fluctuations during window cleaning, adversely affecting the image forming process, and causing image distortion.

Further, due to the shape of the developer accommodating container and the structure of the developer accommodating container, in order to properly detect the presence or absence of the developer, the detection position is considerably restricted. There are restrictions on the shape and even the configuration relationship with the main body centering on the paper transport path, which may be inconvenient even in terms of improving the maintenance of the machine and improving the space efficiency inside the machine to reduce the size of the device. .

An object of the first invention of the present application is to solve the above-mentioned problems and to notify the user of a sudden developer shortage by detecting the remaining amount (consumption amount) of the developer. Instead, notifying the remaining amount of the developer makes it more kind.

The second object of the present invention is to:
The residual amount of the developer can be easily detected by the natural accumulation of the developer in the developer container.

Further, the object of the third invention according to the present application is to:
Even when the amount of the developer in the developer storage container is reduced depending on the location, the accuracy of detecting the remaining amount of the developer is further ensured.

A fourth object of the present application is to eliminate the complicated structure of the mechanism inside the developer accommodating container due to the provision of the developer detecting means and the accompanying adverse effect on the image.

Further, a fifth object of the present application is to minimize the restriction on the machine body due to the provision of the developer detecting means, and to improve the maintainability and downsize the apparatus.

A sixth object of the present application is to enable the remaining amount of the developer to be properly detected even when the optimum arrangement position of the detecting means is near the paper conveying road surface.

[0016]

According to the first invention of the present application, the above object has a developer container for containing a developer, and stores the developer in accordance with image information. In the image forming apparatus for recording in the above, it is achieved by providing a detecting means capable of detecting the presence or absence of the developer from the outside of the developer accommodating container and a moving means for moving the detecting means, and making the detecting means movable. To be done.

According to the second invention of the present application,
The above-mentioned object is achieved in the above-mentioned first invention by the fact that the detecting means is vertically movable along the outer wall of the developer accommodating container.

Further, according to the third invention of the present application, in the above-mentioned first invention, the detecting means is movable on the two-dimensional plane in the vertical and horizontal directions along the outer wall of the developer accommodating container. It is achieved by something.

According to the fourth invention of the present application, the above object can be achieved by using the magnetic material as the developer and the magnetic permeability detecting system as the detecting means in the first invention.

Further, according to the fifth invention of the present application, in the above-mentioned first invention, the detecting means is brought into contact with the outer wall of the developer accommodating container only for a certain period of time, and the development is performed for a period of time other than the certain period. This is achieved by providing a moving means so as to be retracted from the agent storage container.

According to the sixth invention of the present application, the above-mentioned object is achieved by the detecting means moving in synchronization with the detection signal of the front or rear end of the recording medium in the first invention. It

[0022]

According to the first invention of the present application, a developer accommodating container for accommodating the developer is provided outside the developer accommodating means, and a detecting means capable of detecting the presence or absence of the developer without contact is provided. By having the moving means for moving the means and making the detecting means movable, the position for judging the presence or absence of the developer can be known, so that the remaining amount of the developer can be detected.

According to the second invention of the present application,
Since the detection means is vertically movable along the outer wall of the developer storage container, the remaining amount of the developer in the developer storage container which is naturally accumulated due to its own weight is detected.

Further, according to the third invention of the present application,
Since the detecting means is movable on the two-dimensional plane in the vertical and horizontal directions along the outer wall of the developer accommodating container, even if the developer in the developer accommodating container is reduced in different places, the residual amount of the developer remains. The amount is accurately detected.

Further, according to the fourth invention of the present application, since the magnetic material is used for the developer and the magnetic permeability detecting system is used as the detecting means, it is necessary to complicate the mechanism structure in the developer accommodating container. To eliminate the adverse effects on the image.

Further, according to the fifth invention of the present application,
Since the detection means is in contact with the outer wall of the developer storage container only for a certain period of time, and is kept away from the developer storage container for a certain period of time, the moving means is provided to minimize the restrictions on the machine body. To improve maintenance and miniaturize the device.

According to the sixth invention of the present application,
Since the detecting means moves in synchronization with the detection signal of the leading edge or the trailing edge of the recording medium, the detecting means is moved to the gap of the recording medium being conveyed even when the optimum arrangement position of the detecting means is near the recording medium conveying road surface. However, the remaining amount of the developer is properly detected by contacting the outer wall of the developer accommodating container only for a certain period of time.

[0028]

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

(First Embodiment) An example applied to a facsimile apparatus as a first embodiment according to the present invention will be specifically described with reference to the drawings. Here, as the order of explanation,
It will be described in the following order. Facsimile device overall configuration, reading device configuration for reading information, image forming device configuration for recording received information, process cartridge components used in the image forming device, magnetic bridge sensor as detecting means Description, configuration of the remaining amount detection means by the detection means provided outside the toner container.

{Overall Structure of Facsimile Device} FIG. 1 is a structural explanatory view of a facsimile device having an image forming apparatus having a process cartridge according to the present invention, and FIG. 2 is an external perspective view thereof.

As shown in FIG. 1, this facsimile device has a document reading device A above and an image forming device B below it. Then, the information read by the reading device A is transmitted to the other facsimile device in the facsimile mode, and recorded in the image forming device B of its own in the copy mode.

As shown in FIG. 1, the image forming apparatus B irradiates an optical image based on image information from the optical means 1 to form a toner image on the photosensitive drum 7 which is an image carrier.
Then, the recording paper 2 is conveyed by the conveying means 3 in synchronization with the formation of the toner image, and the toner image formed on the photoconductor drum 7 in the image forming portion formed as a process cartridge C is recorded by the transfer means 4. The recording sheet 2 is transferred onto a sheet 2, the recording sheet 2 is conveyed to a fixing unit 5, the transferred toner image is fixed, and the sheet is discharged to a discharge tray 6. As shown in FIG. 1, the process cartridge C constituting the image forming section rotates the photosensitive drum 7 to uniformly charge the surface thereof by the charging means 8 to expose the optical image from the optical system 1. The photosensitive drum 7 is exposed through the section 9 to form a latent image, and the developing means 10 forms a toner image corresponding to the latent image to visualize the latent image. After the transfer means 4 transfers the toner image onto the recording paper 2, the cleaning means 11 removes the toner remaining on the photosensitive drum 7. The parts such as the photosensitive drum 7 are made of resin and
The upper frame body 12a, which is a frame, and the lower frame body 12b, which is the second frame, are housed in a housing 12 configured to be a cartridge.

The toner container 10a of the process cartridge C is provided with an agitating means 19 for agitating the toner, and the main body side serves as a detecting means for detecting the amount of toner remaining in the toner container 10a. A magnetic bridge sensor 20 for detecting the magnetic permeability is provided.

[Reading Device] The reading device A conveys the document 13 and reads the information described in the document. As shown in FIG. 1, the structure is such that the original 13 stacked on the original placing table 14a is separated by a preliminary conveying roller 14b _{2 in} pressure contact with a preliminary conveying pressing piece 14b ₁ and a separation roller 14d in pressure contact with a reverse roller 14c. After the information is read from the original 13 while the original 13 is pressed by the pressing means 14e and brought into close contact with the contact type sensor of the reading means 15, the original 13 is discharged to the original discharge tray 14g by the discharge roller 14f. Is.

The reading means 15 is an LED as a light source.
The information recording surface of the manuscript 13 is irradiated with light from 15a, and the reflected light is transmitted through the short-focus imaging lens 15b to the photoelectric conversion element 15
The image is formed on c and the information is read, and the signal is transmitted to another machine in the facsimile mode through the control means described later, and is transmitted to its own image forming apparatus B in the copy mode.

A slider 14h is provided on the document table 14a so as to be slidable in a direction perpendicular to the direction in which the document 13 is conveyed (width direction of the document 13). The slider 14h is slid in accordance with the width of the document 13. As a result, both sides of the document 13 stacked on the document placing table 14a can be aligned.

{Image Forming Apparatus} Next, regarding the configuration of each part of the image forming apparatus B which forms an image in response to a recording signal,
a. Optical means, b. Transport means, c. Transfer means, d. Fixing means, e. The cartridge mounting means will be described in this order.

(A. Optical Means) The optical means 1 irradiates a light image on the photosensitive drum 7 by irradiating light on the basis of image information read from an external device or the like.
As shown in, a laser diode 1b, a polygon mirror 1c, a scanner motor 1d,
The imaging lens 1e is stored.

Then, for example, when an image signal is given from a facsimile machine of another machine, the laser diode 1b emits light according to the image signal and illuminates the polygon mirror 1c as image light. This polygon mirror 1c is rotated at a high speed by a scanner motor 1d,
The image light reflected by c is formed by the imaging lens 1e and the reflection mirror 1.
The rotating photoconductor drum 7 is irradiated via f and the surface of the drum 7 is selectively exposed to form a latent image according to image information.

(B. Recording Paper Conveying Means) Next, the conveying means 3 for conveying the recording paper 2 is arranged at the lower position of the image forming apparatus B and is attached so as to be pulled out from one end of the paper feeding section D. The topmost sheet of the recording paper 2 loaded in the feeding cassette 3a is separated into the separation claws 3a provided at the corners of the leading edge of the recording paper 2.
₁ and a feeding roller 3b having a shape in which a part of a circle is cut away to feed the sheets one by one, and the cassette feeding roller pair 3c feeds the feeding roller pair 3d, and the feeding roller pair 3d forms an image. The recording paper 2 is conveyed to the image transfer section in synchronization with the operation. Then, the recording paper 2 after the image transfer,
The guide plate 3e conveys the recording paper 2 to the fixing unit 5, and the recording paper 2 after fixing is discharged to the discharge tray 6 by the discharge roller pair 3f.

(C. Transfer Unit) The transfer unit 4 transfers the toner image formed on the photosensitive drum 7 in the image forming section onto the recording paper 2. The transfer unit 4 of this embodiment is shown in FIG. As described above, the transfer roller 4 is used. That is, the recording paper 2 is pressed against the photosensitive drum 7 of the mounted process cartridge C by the transfer roller 4, and a voltage having a polarity opposite to that of the toner image formed on the photosensitive drum 7 is applied to the transfer roller 4. The toner on the photosensitive drum 7 is transferred to the recording paper 2.

(D. Fixing Unit) The fixing unit 5 fixes the toner image transferred onto the recording paper 2 by applying a voltage to the transfer roller 4. As shown in FIG. 1, the structure is such that a driving roller 5a that is driven to rotate and a heater 5b are provided inside.
And a fixing member 5c having a sheet member that is driven to rotate by being pressed against the driving roller 5a. That is, when the recording paper 2 to which the toner image has been transferred in the image forming section passes between the drive roller 5a and the fixing member 5c, both
The pressure is applied by pressing c, and heat is applied by the heat generation of the heater 5b, so that the toner on the recording paper 2 is fixed on the recording paper 2.

(E. Process Cartridge Mounting Unit) Inside the image forming apparatus B, a cartridge mounting unit for mounting the process cartridge C is provided. The process cartridge C is attached to and detached from the apparatus main body 16 by opening the opening / closing cover 17. That is, as shown in FIG. 1, an opening / closing cover 17 that can be opened and closed by a hinge 17a is attached to the upper portion of the apparatus body 16. When the opening / closing cover 17 is opened, a cartridge mounting space is provided in the apparatus body 16, and guide grooves (not shown) are provided on the left and right wall surfaces of the space. The process cartridge C is inserted into the guide groove along the drum shaft, and the opening / closing cover 17 is closed to mount the process cartridge C in the image forming apparatus B.

{Process Cartridge} Next, the structure of each part of the process cartridge C mounted in the image forming apparatus B will be described.

The process cartridge C comprises an image carrier and at least one process means. Here, the process means includes, for example, a charging means for charging the surface of the image carrier, a developing means for forming a toner image on the image carrier, and a cleaning means for cleaning the toner remaining on the surface of the image carrier. In the process cartridge C of this embodiment, as shown in FIG. 1, a charging unit 8 is provided around an electrophotographic photosensitive drum 7 which is an image carrier.
An exposure unit 9, a developing unit 10, and a cleaning unit 11 are arranged, and these are covered with a housing 12 so as to be integrated with each other.

Next, the structure of each part of the process cartridge C is described in a. A photosensitive drum, b. Charging means, c. Exposure unit,
d. Developing means, e. The cleaning means will be described in this order.

(A. Photosensitive drum) The photosensitive drum 7 according to the present embodiment is constructed by coating an organic photosensitive layer on the outer peripheral surface of a drum base made of cylindrical aluminum. The photosensitive drum 7 is rotatably attached to the frame, and the driving force of a drive motor provided on the apparatus main body side is transmitted to a flange gear fixed to one end of the photosensitive drum 7 in the longitudinal direction. Is rotated in the direction of the arrow in FIG. 1 according to the image forming operation.

(B. Charging means) The charging means is for uniformly charging the surface of the photosensitive drum 7, and in the present embodiment, the charging roller 8 is rotatably attached to the frame, so-called. The contact charging method is used. The charging roller 8 has a metal roller shaft 8a provided with a conductive elastic layer, a high resistance elastic layer further provided thereon, and a protective film provided on the surface thereof. The conductive elastic layer is formed by dispersing carbon in an elastic rubber layer such as EPDM or NBR and has a function of guiding a bias voltage supplied to the roller shaft. Further, the high resistance elastic layer is made of urethane rubber or the like and contains a minute amount of conductive fine powder, and even when a pinhole of the photosensitive drum 7 or a charging roller of high conductivity is opposed, The leak current to the photosensitive drum 7 is limited to prevent the bias voltage from rapidly dropping. The protective layer is N-
It is composed of methyl methoxylated nylon, and acts so that the composition material of the conductive elastic layer and the elastic layer of high resistance does not touch the photoconductor drum 7 and deteriorate the surface of the photoconductor drum 7.

The charging roller 8 is connected to the photosensitive drum 7
When the image is formed, the charging roller 8 rotates following the rotation of the photoconductor drum 7. At this time, the DC voltage and the AC voltage are superimposed and applied to the charging roller 8 to apply the DC voltage to the photoconductor drum 7. Charge the surface uniformly.

(C. Exposure unit) The exposure unit 9 exposes the surface of the photosensitive drum 7 uniformly charged by the charging roller 8 with the optical image irradiated from the optical system 1 to electrostatically expose the surface of the drum 7. This is for forming a latent image, and an exposure section is formed by providing an opening on the upper surface of the cartridge frame for guiding the optical image.

(D. Developing Unit) As shown in FIG. 1, the developing unit 10 includes a toner container 10a which is a toner container.
A toner is housed inside, and a stirring member for feeding and stirring the toner is provided so as to be able to reciprocate, as will be described later. A developing sleeve 10c has a non-rotating magnet 10b inside the opening of the toner container 10a and forms a thin toner layer on the surface by rotating.
Are provided at a minute distance from the photosensitive drum 7.

The developing sleeve 10c is formed by roughening the surface of an aluminum cylindrical member by sandblasting,
When a toner layer is formed on the surface of the developing sleeve 10c, a conductive coating material in which a pigment is dispersed is applied onto the surface of the developing sleeve 10c. Obtain sufficient triboelectric charge to develop the latent image. A developing blade 10d is provided to regulate the toner layer thickness.

A stirring member 19 for stirring the toner is provided in the toner container 10a.
The toner stirring structure will be described later.

(E. Cleaning Unit) As shown in FIG. 1, the cleaning unit 11 has a cleaning blade 11a for contacting the surface of the photosensitive drum 7 and scraping off the toner remaining on the drum 7. A squeeze sheet 11b positioned below the blade 11a for scooping the scraped off toner and weakly contacting the surface of the photosensitive drum 7, and a waste toner reservoir 11c for storing the scraped off toner. I am configuring.

(F. Stirring Means) The stirring means stirs the toner in the toner container 10a and sends it to the developing sleeve 10c. As shown in FIG. 1, a stirring member 19 is provided in the toner container 10a. It is provided and configured. The stirring member 19 is formed by connecting a plurality of rod-shaped members each having a triangular cross section at regular intervals and integrating them. When a gear and an arm (neither is shown) are actuated by receiving drive transmission from the same drive source as the photosensitive drum 7 rotates, the stirring member 19 connected by the shaft 19a provided on the tip side is indicated by an arrow X.
The toner reciprocates in the direction to prevent toner aggregation and uneven distribution.

{Magnetic Bridge Sensor} The magnetic bridge sensor 20 described above is integrally formed by mounting the detection head 20a in a cylindrical shape on the main body as shown in FIG. The detection signal is exchanged with the main body of the facsimile apparatus via the signal line 20b.

A detection transformer is embedded inside the detection head 20a, and this detection transformer has a total of one primary winding and two secondary windings including a reference winding and a detection winding. It consists of three windings. The detection winding is located on the top side of the detection head, and the reference winding is located on the back side of the detection head with the primary winding interposed therebetween.

When a current having a signal of a constant waveform is input to the primary winding from an oscillator provided in the sensor body, electromagnetic induction is also applied to the two secondary windings including the reference winding and the detection winding. Causes a current having a signal of a certain waveform to flow. At this time, by comparing the signal of a constant waveform from the oscillator and the signal of a waveform with a current flowing from the detection winding due to electromagnetic induction with the comparison circuit provided in the sensor body, The density of the magnetic substance on the surface side is detected. That is, different outputs can be obtained with and without the magnetic substance in front of the detection head.

Further, in order to cope with the difference in magnetic density of the magnetic substance to be detected, this sensor is provided with a ferritic screw core movably in the center of the detection transformer, and the position of this screw core should be adjusted. This enables proper detection.

{Remaining Amount Detecting Unit} The remaining amount detecting unit detects the remaining amount of toner stored in the toner storage container 10a by the magnetic bridge sensor 20. As shown in FIG. 1, the structure is such that the toner storage container 1 is provided in the main body.
Detection head side wall 10a ₁ of 0a is is provided with the magnetic bridge sensor 20 so as to face a side wall of the toner storing container 10a while detecting head 20a is opposed 1
Move up and down along 0a ₁ .

The moving mechanism of the magnetic bridge sensor 20 is shown in FIG. Side wall 10a of toner container 10a
_A sensor guide 21 is provided in parallel with _1, and a sensor holder 22 is provided to move the magnetic bridge sensor 20 up and down along the sensor guide 21. The sensor holder 22 is provided with a round elongated hole 22a for fitting in the lateral direction. On the other hand, a disk 23 having a fitting eccentric boss 23a is pivotally supported on the main body side, and the eccentric boss 23a and the round elongated hole 22a are fitted together. The disk 23 is connected to a feeding roller 3b for feeding recording paper by a transmission belt (not shown) so that the rotation speed ratio is 1: 1. Further, a photo interrupter 24 having a light emitting element and a light receiving element integrated is provided on the main body side so that the reference position of the sensor holder can be detected.

When the recording operation is started, the feeding roller 3b makes one rotation to separate and feed the recording papers 2 one by one, and the drive is transmitted to the transmission belt to make one rotation of the disc. The sensor holder 22 fitted to the provided eccentric boss 23 a moves up and down once along the sensor guide 21. At this time, the reference position of the magnetic bridge sensor 20 is recognized by passing a part of the sensor holder 22 through the detection unit of the photo interrupter 24.

FIG. 5 shows the detection signal of the photo interrupter 24 and the analog detection signal of the magnetic bridge sensor 20 when the remaining toner amount is large and small, with the horizontal axis representing the time axis.

During standby, the sensor holder 22 is at the bottom dead center position of the vertical movement range, and the sensor holder 22
Since the position detection unit 22b of FIG. 3 blocks the detection unit of the photo interrupter 24, the detection signal of the photo interrupter 24 is an output on the LOW side. At this time, since the position of the magnetic bridge sensor 20 is where the toner remains, the analog detection signal of the magnetic bridge sensor 20 is an output with toner. Also, the process cartridge C
If it is not attached, it is determined that there is no toner. When the sensor holder 22 starts moving upward,
First, since the position detection unit 22b of the sensor holder 22 passes through the detection unit of the photo interrupter 24, the detection signal of the photo interrupter 24 becomes HIGH. When the sensor holder 22 continues to move, the analog detection signal of the magnetic bridge sensor 20 suddenly changes when the magnetic bridge sensor 20 reaches the boundary of the presence or absence of toner, and the absence of toner is detected. When the sensor holder 22 continues to move further, the sensor holder 22 reaches the top dead center,
Start moving downwards. This time magnetic bridge sensor 2
When 0 comes to the boundary of the presence or absence of toner, the analog detection signal of the magnetic bridge sensor 20 suddenly changes to detect the presence of toner. Since the position detection unit 22b of the sensor holder 22 blocks the detection unit of the photo interrupter 24, the detection signal of the photo interrupter 24 becomes an output on the LOW side, and then the sensor holder 22 reaches the bottom dead center position of the vertical movement range. By the way, stop moving.

Here, from the time when the detection signal of the photo interrupter 24 becomes HIGH side, the magnetic bridge sensor 2
The analog detection signal of 0 drastically changes, and the time difference Δt when the absence of toner is detected is calculated, and the toner storage container 10a
The remaining toner amount is calculated by converting the remaining toner amount into the height. That is, when the remaining toner amount is large, Δt is long as shown in FIG.
As shown in (b), Δt becomes short and the remaining toner amount can be detected. By detecting the position of the magnetic bridge sensor 20 with the photo interrupter 24 and detecting the remaining amount by the time difference to the boundary position of the presence or absence of toner, the toner remaining amount can be detected with high accuracy.

Since the output change indicated by the analog detection signal of the magnetic bridge sensor 20 at the boundary of presence or absence of toner has a certain width of time, a slice level is set with a constant detection signal, and the boundary of presence or absence of toner is determined at that time. Deciding.

By displaying the remaining amount of toner thus detected on the operation panel 25 shown in FIG. 2, the user is informed of the remaining amount of toner and the standard of the cartridge replacement time. Further, when the remaining toner amount that can be detected becomes less than a certain predetermined toner remaining amount, it is determined that the toner is out of toner in the toner storage container, and the operation panel 25 indicates that there is no toner, and at the same time the facsimile device records. The operation is prohibited to prevent the image information from being lost due to the print blur of the recorded image.

(Second Embodiment) Next, as a second embodiment, a method of accurately detecting the remaining toner amount when the toner is reduced in different directions in the width direction of the recording paper will be described.

In addition to the mechanism shown as the first embodiment, the sensor guide 21 may be moved together with the magnetic bridge sensor 20 in the paper width direction. For example, a mechanism for stopping the paper width at regular intervals divided into integers is provided, and the remaining amount is detected once for each recording operation. If the number of even integers is large, the accuracy increases depending on the location, but an error corresponding to the number of sheets is generated. Therefore, in that case, it is necessary to detect the remaining amount a plurality of times for one recording operation.

In a facsimile apparatus, there are many cases where there is no person at the time of reception, and there is a case where the sender of information does not know what kind of image information is sent. Is difficult to recognize. Therefore, by detecting the remaining amount of toner at a plurality of positions in the paper width direction, it is possible to detect where there is a large amount of toner depletion, and therefore it is possible to almost completely prevent the loss of image information due to print blur of a recorded image. .

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment, the proper detection position of the magnetic bridge sensor is located on the recording paper conveyance path surface of the toner storage container, and it is possible to accurately detect the remaining toner amount also in this embodiment. Since the facsimile apparatus main body uses a facsimile apparatus similar to that described in the first embodiment, it will be omitted here and only different remaining amount detecting means will be described.

As shown in FIG. 6, the magnetic bridge sensor 2
No. 0 has a shaft portion 26a, and the shaft portion 26a has a body 16
It is attached to a sensor holder 26 that is rotatably fitted in a hole portion 26b provided in the above and is movable.
Further, in order to properly detect the toner remaining amount detection head 20a across the conveyor pathway of the recording paper 2 to the bottom wall 10a ₂ of the toner storing container 10a is arranged to face, further,
An electromagnetic solenoid 27 for moving the 26 position of the sensor holder is provided.

When the remaining toner amount is not detected, the top surface of the detection head 20a is retracted to a position where it does not project beyond the recording paper guide 28 of the apparatus main body 16 so that the magnetic bridge sensor 20 does not hinder the passage of the recording paper 2. are doing.

When the remaining amount of toner is detected, a predetermined current is passed through the electromagnetic solenoid 27, the central shaft 27a as an actuator is projected, and the sensor holder 26 is moved as shown by a broken line to detect the magnetic bridge sensor 20. The top surface of 20a is brought into contact with the bottom wall 10a ₂ of the toner storage container 10a to detect the toner remaining amount. The amount of toner facing the top surface of the detection head 20a of the magnetic bridge sensor 20 changes depending on the amount of toner remaining in the toner storage container, and the magnetism of the detection portion changes, so the output of the magnetic bridge sensor 20 changes. , Toner level can be detected.

The timing at which an electric current is applied to the electromagnetic solenoid 27 is a signal from a sensor for detecting the leading and trailing edges of the recording sheet 2 provided near the pair of conveying rollers 3d for adjusting the conveying amount of the recording sheet 2 at the recording position. The magnetic bridge sensor 20 is moved to move the magnetic bridge sensor 20 to move the magnetic bridge sensor 20 to the top surface of the detection head 20a so that the toner storage container 10 is controlled.
It is brought into contact with the bottom wall 10a ₂ of a.

In this way, the top surface of the detection head 20a of the magnetic bridge sensor 20 is brought into contact with the bottom wall 10a2 of the toner container 10a to detect the remaining toner amount,
Since the distance between the detection head 20a and the toner can be set to be as short as possible, the difference in the output of the magnetic bridge sensor 20 can be made large depending on the presence / absence of the toner, and the remaining toner amount can be accurately detected. In general, in order for the magnetic bridge sensor 20 to detect the presence or absence of a magnetic substance such as toner, the distance between the detection head 20a and the toner must be experimentally shortened to a maximum of about 3 mm. Accurate detection of the remaining toner amount cannot be expected in a state where the top surface of the detection head 20a is retracted to a position where it does not project beyond the recording paper guide 28 of the apparatus body so as not to hinder the passage of the recording paper 2.

[0078]

As described above, the first aspect of the present application
According to the invention, in the image forming apparatus which has the developer accommodating container for accommodating the developer and records the developer on the recording medium according to the image information, the outside of the developer accommodating container is contactless. The presence / absence of a developer is determined by the movement of the detection means by having a detection means capable of detecting the presence or absence of the developer and a moving means for moving the detection means. It is possible to detect the remaining amount (consumed amount) of the developer because the position to be used can be detected, and it is possible to give more kindness by notifying the user of the sudden depletion of the developer, but notifying the remaining amount of the developer. it can.

According to the second invention of the present application,
By allowing the detection unit to move vertically along the outer wall of the developer container, the remaining amount of the developer in the developer container can be detected by its own weight, and the remaining amount of developer can be detected. Can be easily detected.

According to the third invention of the present application,
By making the detecting means movable along the outer wall of the developer accommodating container on a two-dimensional plane in the vertical and horizontal directions, even when the developer in the developer accommodating container is reduced in different places, the development The remaining amount of the developer can be accurately detected, and the accuracy of detecting the remaining amount of the developer can be further ensured.

According to the fourth invention of the present application,
By using a magnetic material for the developer and adopting the magnetic permeability detection method as the detection means, the need for complicating the mechanical structure inside the developer storage container due to the provision of the developer detection means is eliminated, and the image accompanying it is eliminated. It is possible to eliminate the adverse effect on.

According to the fifth invention of the present application,
The developer detecting means is provided by providing the moving means so that the detecting means is in contact with the outer wall of the developer accommodating container only for a certain time and is kept away from the developer accommodating container except for a certain time. Minimize the restrictions on the machine body due to
It is possible to promote maintenance and downsizing of the device.

According to the sixth invention of the present application,
By moving the detection means in synchronization with the detection signal of the leading edge or the trailing edge of the recording paper, even if the optimum arrangement position of the detection means is near the paper conveyance path, the detection means is moved to the gap of the paper being conveyed. The remaining amount of the developer can be detected by contacting the outer wall of the developer accommodating container only for a certain period of time.

[Brief description of drawings]

FIG. 1 is a configuration sectional view of a facsimile apparatus according to a first embodiment of the present invention.

2 is an external perspective view of the facsimile apparatus of FIG.

3 is an external perspective view of a magnetic bridge sensor used in the apparatus shown in FIG.

4 is a cross-sectional configuration diagram of a moving mechanism of the magnetic bridge sensor used in the apparatus shown in FIG.

FIG. 5 is a timing chart of a toner presence / absence detection signal according to the first embodiment of the present invention.

FIG. 6 is a structural cross-sectional view of a moving mechanism of a magnetic bridge sensor according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of the configuration of a developer presence / absence detection device according to a conventional example.

[Explanation of symbols]

2 recording paper (recording medium) 10a toner container (developer container) 10a ₁ side wall (outer wall) 10a ₂ bottom wall (outer wall) 20 magnetic bridge sensor (detection means)

Claims (6)

[Claims] 1. An image forming apparatus having a developer accommodating container for accommodating the developer, wherein the developer is recorded on a recording medium according to image information, and the presence or absence of the developer is checked from the outside of the developer accommodating container. An image forming apparatus comprising: a detection unit that can be detected and a moving unit that moves the detection unit, and the detection unit can be moved. 2. The image forming apparatus according to claim 1, wherein the detection means is movable in the vertical direction along the outer wall of the developer accommodating container. 3. The image forming apparatus according to claim 1, wherein the detection unit is movable along a two-dimensional plane in the vertical and horizontal directions along the outer wall of the developer accommodating container. 4. The image forming apparatus according to claim 1, wherein a magnetic material is used as the developer, and the detection means is a magnetic permeability detection system. 5. The moving means is provided so that the detecting means is in contact with the outer wall of the developer accommodating container only for a certain period of time, and is kept away from the developer accommodating container except for a certain period of time. The image forming apparatus according to Item 1. 6. The image forming apparatus according to claim 5, wherein the detection unit moves in synchronization with a detection signal at the leading edge or the trailing edge of the recording medium.