JPS62164075A - Image forming device - Google Patents

Abstract

PURPOSE:To supply an appropriate offset preventing agent and to prevent the occurrence of a stain caused by an offset or the offset preventing agent and unnecessary consumption by providing an offset preventing agent supply control means controlling the supply of the offset preventing agent to a fixing device in accordance with the type of toner. CONSTITUTION:If image formation by toner with a poor fixing ability is selected through a toner color selection button 30 on a console panel, a transfer paper 16 on which a toner image 15 is formed with bone toner comes in the fixing device 11 where a CPU 31 operates from a signal through the toner color selection button 30. The OFF tie of a solenoid 28 is made longer through a driver 32, and the applying amount of silicone oil to a fixing roller 13 is increased. For forming an image by red toner with an excellent fixing ability, the CPU 31 shortens the OFF time of the solenoid 28 through the driver 32 with the aid of the signal from the toner color selection button 30, and reduces the applying amount of silicone oil to the fixing roller 13.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides an image forming apparatus [3] that can form images using a plurality of different toners or each toner individually.

(Prior Art) Conventionally, in image forming apparatuses such as copying machines,
Image formation has been performed using various types of toner, but in recent years,
Devices have been proposed that use red and blue color toners in combination. However, in general, black toner and color toner often have different fixing properties due to differences in their components. For example, a two-component toner containing a magnetic carrier is used for the black toner, and a 1#:minute toner containing no carrier that inhibits color vividness is used for the color toner VC. In this case, two-component toner containing a carrier has poorer fixing properties than one-component toner due to the shadow 4 of the carrier, and when images are formed using these toners with different fixing properties, a difference occurs in the degree of fixing.

Generally, as a device for fixing a toner image transferred to a transfer paper, a heat roller fixing device including a heat roller and a pressure roller is used. At that time, in order to completely prevent the toner image from being transferred and attached from the transfer paper to the heating roller, and then from staining the transfer paper and deteriorating the image quality, an anti-offset agent is applied to the heating roller. Supply means are provided.

(Problems to be Solved by the Invention) However, such prior art has the following problems. i.e. thermal energy.

If fixing settings such as pressure energy are kept constant and offset preventive agent is supplied according to toner with good fixing properties, images made with toners with poor fixing properties will have poor fixing properties, and offset prevention will result. There is a problem in that the supply of the agent is insufficient and offset occurs, which deteriorates the image quality. On the other hand, if the anti-offset agent is supplied in accordance with the toner with poor fixing properties, the image produced by the toner with good fixing properties will be affected by excessive supply of the anti-offset agent.
Anti-offset agents such as silicone oil stains occur,
Decrease image quality. Furthermore, more offset inhibitor than necessary is supplied, which poses a problem from the viewpoint of cost reduction.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art.The purpose of the present invention is to always supply an appropriate anti-offset agent even when toner fixability is different, and to prevent offset and offset. An object of the present invention is to provide an image forming apparatus capable of preventing stains and unnecessary consumption of an inhibitor.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides an image forming apparatus capable of forming an image using a plurality of different toners or each individual toner. The apparatus is configured to include an anti-offset agent supply control means for controlling the supply of anti-offset agent to the apparatus.

(Example) The present invention will be explained below based on illustrated embodiments.

In FIG. 4, 1 is a photosensitive drum, and this photosensitive drum 1
consists of a photoreceptor with a photoconductive layer covered with a transparent insulating layer,
As the photoreceptor drum 1 rotates, it first charges a negative charger 2.
It is charged by Subsequently, when reaching the exposure section 3, an image of the original (not shown) is exposed. Next, an electrostatic latent image is formed on the surface of the photosensitive drum 1 by full exposure by the full surface exposure lamp 4, and reaches the developing devices 5 and 6. These developing devices 5 and 6 use toners of different colors and different fixing properties. The developing device 5 uses black toner, and this black toner is a two-component toner containing a magnetic carrier. On the other hand, red toner is used in the developing device 6, and this red toner is a one-component toner that does not contain carriers that limit the vividness of the colors. The developing device 5.sub.6 is selected by operating a toner color selection operation on an operation panel (not shown), and a companion developing device approaches the photosensitive drum 1. The toner in the developing device 6 has relatively better fixing properties. Development is performed by powder development using a magnetic sleeve method, and the electrostatic latent image is visualized.

Thus, by pressing the toner color selection button (not shown) on the operation panel A, the operator can make copies in two colors, black and red. For example, when forming an image using black toner, in order to form an image in black on a predetermined area of the document, the exposure means operates to turn the desired image area into black toner, and the next electrostatic latent image is exposed to light accordingly. It is formed on the drum 1. This electrostatic latent image is developed by the developing device 5, which is moved close to the photosensitive drum 1 in response to a signal from the color selection zetan.

Next, after a black toner image is transferred to a transfer paper (not shown) by a transfer charger 7, this transfer paper is separated from the photosensitive drum 1 by a separation charger 8, and then transferred to a fixing device (described later) by a conveyor belt 50. transported to. After residual toner on the surface of the photosensitive drum 1 is removed by a cleaning device 9, it is illuminated by a pre-exposure lamp 10 to remove residual charges and prepare for the next copying cycle.

Note that when an image is formed using red toner, the process is similar to that for black toner.

FIG. 1 is a schematic diagram showing the fixing device. This fixing device 11 is mainly composed of a fixing roller 13 having a heat source 12 and a pressure roller 14 having a rubber layer on its surface, and a transfer paper 16 for recording a toner image 15 is moved between these rollers that are in pressure contact with each other. The toner image 15 is passed from the middle right direction and fixed on the transfer paper 16 by heat and pressure. On the fixing roller 13, a claw-shaped separating member 17 for peeling off the transfer paper 16 is arranged so that its tip comes into contact with the fixing roller 13. The paper 16 is peeled off from this roller and guided to a predetermined conveyance path. On the other hand, this fixing device 11
is equipped with an anti-offset agent supplying means 18 for supplying an anti-offset agent to the fixing roller 13. That is, an application roller 20t- for applying silicone oil 19 as an anti-offset agent onto the surface of the fixing roller 13;
The blade 21 makes the oil on the surface of the application roller 20 uniform. A first supply roller 23 is immersed in the silicone oil 19 filled in the oil tank 22, and a second supply roller 24 is in contact with the first supply roller 23. 23,
By rotating 24 in the direction of the arrow in the figure, silicone oil 19 is pumped up. Further, a third supply roller 25 is disposed between the second supply roller 24 and the application roller 20, and the third supply port 25 swings around a fulcrum 26. It is pivotally supported at the tip of an arm 27. Due to the ON/OFF state of the solenoid 28 connected to the arm 27 and the elastic force of the spring 29, the third supply roller 25 can simultaneously approach and separate from the second supply roller 24 and the application roller 20. There is. When the solenoid 28 is OFF, the line is solid and silicone oil can be supplied, and when the solenoid 28 is ON, the line is 2.
The state shown by the dotted chain line is reached and the supply of silicone oil stops.

With this configuration, the solenoid 28 is 0N-
By controlling the OFF time, the amount of oil applied to the fixing roller 3 can be controlled.

FIG. 2 is a block diagram showing an offset preventive agent supply control system of the fixing device. Reference numeral 30 is a toner color selection button provided on the operation panel and serves as a next toner identifying means, 31 is a CPU as a control means, 32 is a driver as a driving means, and 28 is the solenoid.

In the above configuration, in the image forming apparatus according to this embodiment, the supply amount of the offset prevention agent is controlled as follows. That is, operation, toner color selection on e-nel 3
If the formation of an image using black toner with poor fixability is selected by 0 and fc, the transfer paper 16 on which the toner image 15 using black (black) toner has been transferred reaches the fixing device 11 as described above.

In this fixing device 11, the CPU 31 is operated by a signal from the toner color selection jet 30, and the solenoid 28 is operated via the driver 32 as shown in the time chart shown in FIG. 3(a). When forming an image using red toner with good fixability, the CPU 31 operates the solenoid 28 via the driver 32 according to the signal from the toner color selection jet 30 as shown in the time chart shown in FIG. 3(b). Operate. Therefore, when an image is formed using black toner with poor fixability, the amount of silicone oil applied to the fixing roller 13 increases because the solenoid 28 is turned off for a long time.

Further, when an image is formed using red toner with good fixing properties, the amount of silicone oil applied to the fixing roller 13 is reduced because the OFF time of the solenoid 28 is short.

FIG. 5 shows another embodiment of the image forming apparatus according to the present invention. The same parts as in the above embodiment are denoted by the same reference numerals. In this embodiment, the developing device is Only one is installed.

That is, when forming an image using toner of a different color, the operator replaces the developing device with another one. Reference numerals 33 and 34 indicate detection plates fixed at different positions on the sides of the developing devices 5 and 6. When these developing devices 5 and 6 are installed in the apparatus, the detection plates 33 and 34 correspond to the detection plates 33 and 34. The photointerrupters 35 provided at each of the nine positions are used to identify the developing devices 5.6. Accordingly, the CPU controls the amount of anti-offset agent to be supplied in accordance with the toner fixability of the identified developing device based on the signal from the photo interrupter 35.

FIG. 6 shows another embodiment of the fixing device.
The same parts as those in the embodiment shown in the figures are given the same reference numerals.
8 is used for tail.

A web 38 fed from a web roll 40 wound around a core metal 39 is pressed against the surface of the fixing roller 13 rotating in the direction A in the figure by a web roller 41. It is sent by the delivery roller 42 and wound around the core bar 43 in the direction B in the figure. Roller for web delivery.

The pair 42 is driven either directly by a motor 44 or via a clutch by an external source. For example, when the web 38 is driven by a stepping motor 44, the feeding speed of the web 38 can be easily changed by changing the driving frequency of the motor. Since the web 38 is impregnated with oil, the amount of oil applied to the surface of the fixing roller 13 can be easily changed by changing the feeding speed. If the feed speed is increased, the amount of oil applied will increase, and if the feed speed is decreased, the amount of oil applied will be decreased. It was,
When the stepping motor 44t is used, the amount of oil applied can be changed by changing the ON-OFF time of the stepping motor 44 without changing the drive frequency. In the case of toner with poor fixability, the ON time of the stepping motor 43 may be lengthened, and in the case of toner with good fixability, the ON time of the stepping motor 44 may be shortened.

Furthermore, when the web feed roller pair 42 is driven by an external drive source via a clutch, the ON-OFF time of the clutch may be changed in the same way as with the stepping motor. The other configurations and operations are the same as those shown in FIG. 1, so their explanation will be omitted.

(Effects of the Invention) The present invention has the above-described structure and operation, and the supply of the anti-offset agent to the fixing device is controlled depending on the type of toner, such as an image using different toners alone or a composite toner image. Therefore, in devices that form images using multiple toners with different fixability, offset may occur due to lack of anti-offset agent, smearing onto transfer paper due to supply of excessive anti-offset agent, and unnecessary offset preventive agent may occur. consumption can be prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a fixing device used in an image forming apparatus according to the present invention, FIG. 2 is a block diagram showing a control system, and FIGS. 3(a) and 3(b) are FIG. 4 is a schematic diagram showing one embodiment of the image forming apparatus according to the present invention, and FIG. 5 is a schematic diagram showing another embodiment of the image forming apparatus according to the present invention. A partial perspective view and FIG. 6 are schematic diagrams of main parts showing another embodiment of a fixing device used in an image forming apparatus according to the present invention. Explanation of symbols 11... Fixing device 15... Toner image 16...
・Transfer paper 18...Offset prevention agent supply child actor 30...Toner color selection zetan 31...CPU 32...Driving means 2B.
... Solenoid Figure 1 Figure 2 Figure 3 (a) (b)

Claims (2)

[Claims] (1) An image forming apparatus capable of forming an image using a plurality of different toners or each individual toner, comprising an offset preventive agent supply control means for controlling the supply of the offset preventive agent to the fixing device according to the type of toner. An image forming apparatus characterized by: (2) The image forming apparatus according to claim 1, wherein a toner image is formed using a plurality of toners having different fixing properties, and each toner image is fixed.