JPH08680Y2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an image forming apparatus provided with a mechanism for detecting a mounting state of a developing device which is detachably attached to a main body.

[Prior Art] In various image forming apparatuses such as copying machines, printers, and facsimiles equipped with a photoconductor, a developing device is arranged so as to develop an electrostatic latent image formed on the photoconductor. This developing device is often configured to be attachable / detachable to / from the main body portion. In the case where the developing device is detachable, the old or new grasp of the developing device is determined by an electrical or mechanical sensor unit. This is because it is important for management or management.

[Problems to be Solved by the Invention] However, in such a conventional image forming apparatus,
The sensor section for detecting the old and new of the developing apparatus complicates the apparatus, and the provision of this sensor section leads to an increase in the size and cost of the apparatus.

Therefore, an object of the present invention is to provide an image forming apparatus in which a sensor unit for detecting old and new of a developing device is simplified, and the size and cost of the apparatus can be reduced.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the invention described in claim 1 is obtained by a developing device detachably attached to a main body and a developing action of the developing device. And an image density detecting mechanism for detecting the toner density of the visible image of the reference pattern, the toner of the visible image of the reference pattern is detected by the image density detecting mechanism when the developing device is mounted on the main body. It has a configuration including a control mechanism for detecting the density and determining whether the developing device is old or new.

According to a second aspect of the present invention, a developing device removably attached to the main body, and an image density for detecting the toner density of the reference pattern visible image obtained by the developing action of the developing device. In an image forming apparatus including a detection mechanism, when the developing device is mounted on the main body, the image density detection mechanism detects the toner density of the reference pattern visible image multiple times to determine whether the developing device is old or new. It has a configuration including a control mechanism for controlling.

Further, the invention described in claim 3 is a developing device detachably attached to the main body portion, a developer supplying portion provided to replenish the developer in the developing device, In an image forming apparatus having an image density detecting mechanism including a sensor for detecting the toner density of a reference pattern visible image obtained by the developing action of the developing device, when the developing device is mounted on the main body part. In addition, the image density detection mechanism is provided with a control mechanism for detecting the toner density of the reference pattern visible image to judge whether the developing device is old or new, and the developer supply section is provided on one end side in the longitudinal direction of the development area. Deployed, the sensor of the image density detection mechanism,
With respect to the central portion in the longitudinal direction of the developing area, it is arranged on the opposite side of the developer supplying portion.

[Operation] In the invention described in claim 1, the image density detecting mechanism constituting the image density control device is used to detect the old and new of the developing device.

According to the second aspect of the invention, like the invention according to the first aspect, the image density detecting mechanism constituting the image density control device is used to detect whether the developing device is old or new. However, in this case, accurate information can be obtained by a plurality of detection operations.

Further, in the device described in claim 3, as in the device described in claim 1, the old and new of the developing device can be detected by using the image density detection mechanism constituting the image density control device. However, the developer is supplied so as not to affect the detection operation of the image density detection mechanism.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

First, the structure of the image forming apparatus according to the present invention will be described with reference to an embodiment of a copying machine shown in FIG.

As shown in FIG. 3, the original document to be copied, which is held on the contact glass 1, is irradiated by the exposure optical system 2 arranged below the contact glass 1 and a light image corresponding to the image is exposed. The body drum 3 is exposed.

The exposure optical system 2 includes a document illuminating light source 201, a first mirror 202, a second mirror 203 and a third mirror 204 which form a first scanner, a through lens 205, and a fourth mirror 206 which forms a second scanner. And a fifth mirror 204. The first scanner is moved rightward in the figure at a speed of (V / m; m is a copying magnification) with respect to the peripheral speed (V) of the photosensitive drum 3, and at the same time, the second scanner is moved to (V / m). It is driven by a drive motor (not shown) so that it can be moved to the right in the figure at a speed of 2 m). The peripheral speed of the photosensitive drum 3 is constant regardless of equal magnification or variable magnification.

An image forming system is arranged in the center of the copying machine main body 1 slightly to the right with the photosensitive drum 3 as the center. That is, around the photosensitive drum 3, a charging charger 4 that uniformly charges the photosensitive drum 3, an eraser 5 that erases unnecessary charges,
Toner powder is supplied to the electrostatic latent image by a magnetic brush to develop the latent image, and a developing device 6 that obtains a toner visible image, a transfer charger 7 that transfers the toner visible image on the photosensitive drum 3 to a recording sheet, and a recording sheet are formed. A cleaning device 8 for cleaning the toner remaining on the photosensitive drum 3 without being transferred is disposed.

The recording paper feeding unit 10 is provided with a paper feeding cassette 101 and an intermediate tray 102 for double-sided copying provided in three stages, and only one recording paper is fed by the calling roller 103 and the paper feeding roller 104. Be done. The fed recording sheet is temporarily stopped by the pair of registration rollers 105, and then fed to the transfer section in synchronization with the leading edge of the image on the photosensitive drum 3. The recording paper on which the toner visible image is transferred by the transfer charger 7 after passing through the pair of registration rollers 105 is fused with the toner visible image by the heat roller pair of the fixing device 11. The recorded paper after fixing is
After passing through the pair of fixed paper ejection rollers, it goes to the main body paper ejection tray or the paper re-feed device.

Further, as shown in FIG. 2, the photosensitive drum 3 as the latent image carrier is rotationally driven in the arrow direction, that is, the clockwise direction by a drive mechanism (not shown). The photoconductor drum 3 is formed of, for example, an organic photoconductor (OPC), is uniformly initially charged to a predetermined potential by the charging charger 4, and is statically formed by an optical image forming action of the exposure optical system 2. A latent image is formed.

Further, a developing sleeve 602 made of a cylindrical member as a developer carrying member is provided in the developing casing 601 of the developing device 6 arranged near the photosensitive drum 3, and a part of the developing sleeve 602. Is exposed from the opening provided in the developing casing 601 toward the photosensitive drum 3 side. The developing sleeve 602 is formed by forming a non-magnetic material such as aluminum into a hollow cylindrical shape. The developing sleeve 602 is rotationally driven in the counterclockwise direction by a drive mechanism (not shown), On the other hand, they are arranged so as to face each other with a certain gap. A toner transfer area, that is, a developing area is formed at a portion where the developing sleeve 602 and the photosensitive drum 3 face each other.

The development area is a belt-shaped area having a longitudinal direction in a direction orthogonal to the drawing in FIG.

On the other hand, a developing magnet roller (not shown) is provided inside the developing sleeve 602, and a magnetic carrier and toner are formed on the outer surface of the developing sleeve 602 by the magnetic force generated from each magnetic pole of the developing magnet roller. The magnetic brush consisting of is made to stand up. The tip of the magnetic brush is elastically contacted with the surface of the photoconductor drum 3 in the above-described developing area.

The developer that composes the magnetic brush is initially the developing casing 60.
It is stored in 1 and is drawn up by the developing sleeve 602 while being stirred by the paddle roller 603. The developer drawn up by the developing sleeve 602 is conveyed to the developing area as a magnetic brush as described above. On the way, the developer doctor 604 arranged close to the developing sleeve 602 cuts the magnetic brush. Is carried out, whereby the amount of the developer is regulated.

The excess developer removed from the developing sleeve 602 by the developing doctor 604 reaches the inclined plate 605 of the separator along the inner curved surface of the developing doctor 604, and
As shown in the figure, the paddle roller 603 is moved while being moved to the front side in the lateral direction (leftward in FIG. 1) by the guiding action of a plurality of fins 606 provided upright on the inclined plate 605.
Being dropped back into the area behind. Further, a developer intake port 607 is provided at the left end portion of the inclined plate 605 in FIG.
The developer dropped through the developer intake port 607 is moved to the inner side in the horizontal direction (right direction in FIG. 1) by the conveying action of the conveying screw 608, and the paddle roller 603 is moved from the right end portion in FIG. It is designed to be dropped into the area above.

In addition, one end side in the longitudinal direction (the left-right direction in FIG. 1) of the developing area, which is the developing casing in this example.
A developer storage container 609 for storing unused new developer is attached to the side plate portion on the front side (left side in the drawing) of 601. A supply port 611 is formed through the developing device side mounting wall of the developer storage container 609, and a shutter 612 is provided between the wall surface of the developer storage container 609 and the side plate portion of the developing casing 601. There is. And this shutter 6
When 12 is pushed down to the state shown in FIG. 1, the supply port 611 of the developer storage container 609 and the opening 613 formed in the side plate portion of the developing casing 601 are communicated with each other. Unused new developer is the development casing 6
It is designed to flow into 01. The developer storage container 609 is provided with a handle portion 614 so as to project toward the front side. By pulling the handle portion 614, the entire developing device 6 is pulled out toward the front side, and the handle portion 614 is provided. By pushing 614, the entire developing device 6 is mounted at a predetermined position on the back side.

On the other hand, on the photoconductor drum 3, a light reflection type sensor (P sensor) 20 of an image density detection mechanism which constitutes an image density control device is arranged so as to face the photoconductor drum 1 in the axial direction or slightly inward. There is. In the present embodiment, that is, as shown in FIG. 2, the sensor 20 is arranged at a position apart from the developing area in the rotation direction of the photoconductor 3, but as shown in FIG. Regarding, regarding the above, it is arranged on the opposite side of the supply port 611 which is the developer supply section.

This light reflection type sensor 20 is an LED 201 as a light emitting element.
And a phototransistor 201 as a light receiving element, and has a function of detecting the toner density of a reference pattern visible image of a predetermined density formed on the photosensitive drum 3. Specifically, the sensor output VSG obtained from the erase area before and after the reference pattern visible image (for example, constant at about 4V) and the sensor output VSP obtained from the reference pattern visible image (for example, 0.3 to 1.2V in the normal state). ) Is to be compared with. Then, the toner density of the visible image of the reference pattern detected by this is captured as the toner density in the developer, and the control operation such as toner replenishment is performed based on it. The present embodiment is provided with a control mechanism that detects whether the developing device 6 is old or new using such an image density detecting mechanism.

That is, first, the replacement operation of the developing device 6 is judged by turning on the main switch or opening and closing the door cover. At this time, when the developing device 6 is replaced with a new one and mounted on the main body, the developer supplying shutter 612 is pushed down to the state shown in FIG.
Unused new developer in 609 is replenished in the developing casing 601. At the same time, the sensor check process by the light reflection type sensor 20 of the image density detecting mechanism constituting the image density control device is repeated three times.

The developer replenished in the developing casing 601 is uniformly diffused by the drive start-up of the developing device 6, but the developer immediately after the developer is replenished is unevenly distributed on the front side in the developing casing 601. Therefore, the developer is pumped up only on the front side of the developing sleeve 602 as well. Therefore, at this point in time, the visible image of the reference pattern is not formed on the photosensitive drum 3, and the value of the sensor output VSP corresponding to the visible image of the reference pattern becomes the sensor output VSG (for example, about 4V) corresponding to the drum surface. Are equal.

In this embodiment, it takes about 30 seconds for the developer to be conveyed to the installation position of the light reflection type sensor 20, but this is a copying time for about 10 sheets of A4 size recording paper. Equivalent to. Therefore, if the sensor check processing by the light reflection type sensor 20 is performed three times in a state corresponding to A4 size, the value of the sensor output VSP corresponding to the reference pattern visible image is the value of the sensor output VSG (for example, about 4
V) is equal to all three times. As a result, the developing device 6 is determined to be new. On the other hand, if the developer is present on the developing sleeve 602, the value of the sensor output VSP will be, for example, 0.3 to 1.2 V in the normal state, and based on this, the developing device 6 is not unused and has already been used. It is determined that it has been used.

In this case, since the developer supply port 611 is installed at the position farthest from the light reflection type sensor 20 of the image density detection mechanism, the supply operation of the developer does not affect the detection operation of the image density detection mechanism. ing.

Originally, the determination as to whether the developing device is old or new by the sensor check process may be performed only once. However, in consideration of the sensor abnormality due to the timing deviation of the reference pattern image, the present embodiment is similar to the present embodiment. It is possible to obtain more reliable information by having the sensor check process performed several times.

The old and new judgment procedures associated with the above-described replacement of the developing device are shown in FIGS. 4 to 7. Note that the normal copy operation is omitted because it is well known.

When mounting the developing device 6 on the main body, that is, when detecting the exchange of the developing device 6, the DT in FIG. 4 STI and FIG. 6 ST2 is detected.
M detection FLAG is set. When it is judged that the developing device 6 has been replaced, that is, when the DTM detection FLAG = 1 in ST3 in FIG. 4, the flow shown in FIG. 7 is executed.

In FIG. 7, the sensor check counter is cleared, that is, CTPCE = 0 is set (ST3), and then the sensor check process is executed (ST4). In the sensor check process, the toner density check of the developing device 6 is performed, and if VSP ≧ 3.0 (ST5) as a result, the same sensor check process is repeated twice (ST6, ST).
7). With these three sensor check processes, even one time VSP <
When it reaches 3.0, the mode is changed to the normal copy mode (ST8, ST
9). However, VSP ≧ 3.0 for all three sensor check processes
In this case, after the developing section stirring process is executed (ST10), the normal copy mode is entered (ST11, ST1).
2).

The agitating process of the developing section described above drives the developing device 6 for about 60 seconds, and aims to uniformly diffuse the developer into the developing part when the replaced developing device 6 is new. .

In this embodiment, the number of times of sensor check processing is set to 3, but the diffusion speed of the developer varies depending on the copying speed, so it is natural that the number of times suitable for each is selected. Further, although the light reflection type sensor is used as the toner concentration control device, other sensors such as a sensor for observing a change in magnetic permeability and a sensor for observing a change in inductance can be similarly adopted.

[Advantages of the Invention] As described above, the invention described in claim 1 is provided with a control mechanism for detecting the old and new of the developing device by using the image density detection mechanism which constitutes the image density control device. Therefore, it is not necessary to provide a special sensor unit, the sensor unit for detecting the old and new developing devices can be simplified, and the size and cost of the device can be reduced.

Further, the invention described in claim 2 is provided with a control mechanism for detecting the old and new of the developing device by utilizing the image density detecting mechanism which constitutes the image density controlling device, and the accurate detecting operation is performed a plurality of times. Since the control mechanism for obtaining information is used, the effect of the invention described in claim 1 can be surely achieved.

Further, the invention described in claim 3 is provided with a control mechanism for detecting whether the developing device is old or new by utilizing the image density detection mechanism which constitutes the image density control device, and the detection operation of the image density detection mechanism. Since the arrangement relationship in which the developer is supplied so as not to affect is adopted, the above-mentioned claim 1
The effect of the invention described in (1) can be achieved more reliably.

[Brief description of drawings]

1 and 2 are a horizontal cross-sectional explanatory view and a vertical cross-sectional explanatory view showing the structure of a developing device according to an embodiment of the present invention.
FIG. 3 is a side view showing a copying machine as an example of an image forming apparatus to which the present invention is applied, and FIGS. 4, 5, 6, and 7 are control procedures by a control mechanism according to the present invention. Is a flow showing. 3 ... Photosensitive drum, 6 ... Developing device, 602 ... Developing sleeve, 604 ... Developing doctor, 605 ... Inclined plate, 606 ... Fin, 6
09: developer storage container, 610: developer supply port.

Claims (3)

[Scope of utility model registration request] 1. A developing device detachably attached to a main body, and an image density detecting mechanism for detecting a toner density of a visible image of a reference pattern obtained by a developing action of the developing device. In the image forming apparatus, when the developing device is mounted on the main body, the image density detecting mechanism is provided with a control mechanism for detecting the toner density of the reference pattern visible image and judging whether the developing device is old or new. Image forming apparatus. 2. A developing device detachably attached to the main body, and an image density detecting mechanism for detecting the toner density of a visible image of a reference pattern obtained by the developing action of the developing device. In the image forming apparatus, when the developing device is mounted on the main body, the image density detecting mechanism includes a control mechanism for detecting the toner density of the reference pattern visible image a plurality of times to judge whether the developing device is old or new. An image forming apparatus characterized by the above. 3. A developing device detachably attached to the main body, a developer supplying portion provided to replenish the developer in the developing device, and a developing action of the developing device. In an image forming apparatus having an image density detecting mechanism including a sensor for detecting the toner density of the obtained reference pattern visible image, the image density detecting mechanism is used when the developing device is mounted on the main body. A control mechanism for detecting the toner density of the visible image of the reference pattern to judge whether the developing device is old or new is provided, and the developer supply section is arranged at one end side in the longitudinal direction of the developing area, The image forming apparatus, wherein the sensor of the detection mechanism is arranged on the opposite side of the developer supply section with respect to the central portion in the longitudinal direction of the developing area.