JPS6126665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for supplying a release liquid to a toner powder image fixing device for fixing a toner powder image onto a recording sheet in an electronic copying apparatus that performs dry development.

The recording sheet on which the toner powder image has been formed is held between a pair of rotating bodies in the rotational axis direction, and the toner powder image is recorded using heat, pressure, or both heat and pressure while conveying the recording sheet. Toner powder image fixing devices for fixing to a sheet are well known.

Problems with such toner powder image fixing devices include that during fixation, the recording sheet may wrap around the rotating body that comes into contact with the toner powder image, and some of the toner may adhere to the surface of the rotating body. However, when a new toner powder image is fixed, this adheres to a new recording sheet, causing a so-called offset phenomenon that stains the image. This may cause toner to adhere to the rotating body or cause deterioration of the fixing function of the fixing device.

Methods to solve these problems include a method of externally supplying a mold release liquid such as silicone oil to the surface of the rotating body that comes into contact with the toner powder image, and a method of supplying a mold release liquid such as silicone oil from the outside to the surface of the rotating body that comes into contact with the toner powder image. A method has been proposed in which the mold release liquid impregnated inside the RTV silicone rubber oozes out onto the surface of the rotating body during fixing.

However, when supplying mold release liquid from outside, it is difficult to control the supply amount of mold release liquid to an appropriate amount.
It tends to be oversupplied, and some of it may drip and stain the parts inside the copying machine, and the release liquid may adhere to the recording sheet and repel ink when writing on the resulting copy. There are drawbacks that make it more difficult to use.

In addition, when using a rotating body coated with RTV silicone rubber impregnated with mold release liquid, there is no problem as long as the mold release liquid is present inside, but once the mold release liquid runs out, the mold release effect is lost. As a result, the above-mentioned problem arose.
Generally, the disadvantage is that the rotating body has a short lifespan.

The object of the present invention is to eliminate such drawbacks,
An object of the present invention is to provide a release liquid supply device in a toner powder image fixing device.

Hereinafter, the present invention will be described by way of examples with reference to the drawings.

FIG. 1 shows only the essential parts of an example of a toner powder image fixing device equipped with a release liquid supply device according to the present invention. That is, in FIG. 1, reference numeral 1 indicates a fixing roller, reference numeral 2 a conveyor belt, reference numeral 3 a heater, reference numeral 4 a reflective plate, reference numeral 5 a release liquid supply device, and reference numeral 6 a release liquid.

The fixing roller 1 and the conveyor belt 2 constitute the above-mentioned pair of rotating bodies. The conveyor belt 2 is composed of a drive roller 21, a tightener roller 22, and an endless belt 23 wrapped around these, and is rotated by the drive roller 21 in the direction of the arrow, that is, clockwise. The rotation axis of the conveyor belt 2 is defined as the rotation axis of the drive roller 21 that is pressed against the fixing roller 1 via the belt 23.

Therefore, the fixing roller 1 and the conveyor belt 2 are
They are in contact with each other with their rotation axes parallel to each other. This contact portion is called a fixing portion.

The surface of the fixing roller 1 is coated with RTV silicone rubber, and the fixing roller 1 rotates counterclockwise following the conveyor belt 2.

The heater 3 cooperates with the reflector and the belt 23
Then, the fixing roller 1 in contact with the belt 23 is heated. The surface temperature of the fixing roller 1 is detected by a heat-sensitive element (not shown), and a control device (not shown) controls the heat generation of the heater 3 so as to keep the surface temperature constant.

The recording sheet S on which the toner powder image P is formed is
It is conveyed from the left to the right in FIG. The toner powder image P is clamped by the conveyor belt 2 in the direction of these rotational axes, and heat and pressure are applied thereto to fix the toner powder image P.

Now, the main parts of the mold release liquid supply device according to the present invention include a roller 51 as a coating member, a mold release liquid storage tank 52, a transmission member 53, a lever 54,
It is composed of an operating rod 55 and a crank 56.

The mold release liquid storage tank 52 stores therein a mold release liquid 6 such as silicone oil, and one end of the contained mold release liquid 6 is immersed in this mold release liquid 6. The transmission member 53 transmits the light to the roller 51 in contact with the other end of the transmission member 53 by capillary action.

The transmission member 53 may be made of any material as long as it has resistance to the mold release liquid and can cause capillary action. For example, felt is one of the suitable materials.

The roller 51 is rotatably held by a holder (not shown) and is in constant contact with the fixing roller 1 .

A protruding piece 5 is provided at the rear end of the release liquid storage tank 52.
21 is provided protrudingly, and a support shaft 52 is attached to this protruding piece 521.
2 are firmly planted. The lever 54 has one end fixed to a support shaft 522, and the support shaft 522 is pivotally supported by the immovable member 100 of the main body of the copying apparatus, so that the release liquid storage tank 52 and the lever 54 are connected to each other.
A degree of freedom of swinging is provided around the support shaft 522. The release liquid storage tank 52 is fixed to the support shaft 522 by a protruding piece 521, and the lever 54 is also fixed to the support shaft 522.
22, and the support shaft 522 is fixed to the stationary member 100.
Since the release liquid storage tank 52 and the lever 54 are rotatably supported by the shaft, the release liquid storage tank 52 and the lever 54 can swing together.

A locking piece 541 is formed at the other end of the lever 54, and one end of the operating rod 55 is engaged with this locking piece 541. The other end of the operating rod 55 is locked to a crank 56, so if the crank 56 is rotated in the direction of the arrow by a drive mechanism (not shown),
The release liquid storage tank 52 can be swung around the support shaft 522, and this oscillation can bring the transmission member 53 into contact with or away from the roller 51.

Now, when the mold release liquid is supplied, the transmission member 53 comes into contact with the roller 51 as shown in FIG. 1, thereby forming a mold release liquid transmission path from the mold release liquid storage tank 52 to the fixing roller 1.

Since the roller 51 is rotatable, it follows the fixing roller 1, holds the mold release liquid supplied by the transmission member 53 on its circumferential surface, rotates clockwise, and holds it on the circumferential surface. Apply release liquid to fixing roller 1
supply to When the release liquid is sufficiently supplied to the fixing roller 1, the friction coefficient between the fixing roller 1 and the roller 51 decreases, and the roller 51 becomes difficult to follow the fixing roller 1.
Excessive supply of mold release agent 6 to the mold can be suppressed.

Furthermore, the crank 56 is rotated to rotate the mold release liquid storage tank 52 clockwise around the support shaft 522, and as shown in FIG. 2, the transmission member 53 is separated from the roller 51 to transmit the mold release liquid. By cutting the path, the supply of the release liquid 6 to the fixing roller 1 can be completely stopped.

Therefore, by bringing the release liquid transmission path into contact with and separating it once per copying cycle, the fixing roller 1 is supplied with the minimum amount of release liquid necessary depending on the consumption state of the release liquid on the roller surface. I can do it.

The release liquid is supplied to the fixing roller 1 once for each copying process, for example, by driving the crank 56 by a cam incorporated in the sequence system of the copying process.

As a result of supplying an appropriate amount of release liquid 6 to the fixing roller 1 in this manner, it has been found that the RTV silicone rubber covering the surface of the fixing roller 1 can be maintained in the condition when it was new for a long period of time. Ta.

By performing the fixing in this manner, the interior of the copying device and the copied image will not be contaminated with the release liquid 6, and the ink can be written onto the copied material well. Furthermore, the fixing roller 1 is not stopped by the release liquid against the conveyor belt 2, and a drive mechanism for the fixing roller 1 is not required.

In order to control the amount of release liquid 6 supplied to the fixing roller 1, the roller 51 and the fixing roller 1 are
Although the contact state between the roller 51 and the fixing roller 1 is a problem, since the roller 51 and the fixing roller 1 are in constant contact with each other, the contact state of these rollers can be easily maintained in an optimum state.

As described above, according to the present invention, it is possible to prevent excessive supply of release liquid to the toner powder image fixing device and maintain a good toner powder image fixing function at all times. A release liquid supply device for a toner powder image fixing device can be provided.

The shape of the applicator may be a roller as in the above embodiments, but it goes without saying that it may also be a belt. The rotational axis of the belt-shaped application member is based on the definition of the rotational axis of the conveyor belt 2 in the above embodiment.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view showing only the essential parts of an embodiment of the present invention, and FIG. 2 is a diagram showing a state in which the application member and the transmission member are separated from each other in the above embodiment. 1... Fixing roller, 2... Conveyance roller, 5
... Release liquid supply device, 51 ... Roller as a coating member, 52 ... Release liquid storage tank, 53 ...
Transmission member, 6... mold release liquid.

Claims (1)

[Claims] 1. A toner of a device that clamps and presses a recording sheet on which a toner powder image has been formed in the direction of a rotating shaft between a pair of rotating bodies, and fixes the toner powder image on the recording sheet using heat, pressure, or both. A device for supplying mold release liquid to the rotating body that comes into contact with the powder image, which is formed in the shape of a roller or a belt, and whose rotational axis is parallel to the rotational axis of the rotating body. a rotatable applicator that contacts a rotary body to which mold liquid is to be supplied; a mold release liquid storage tank; and a capillary development system that transmits the mold release liquid stored in the mold release liquid storage tank to the application member. A transmission member for applying the mold release liquid, and a mold release liquid transmission path from the mold release liquid storage tank to the rotary body to which the mold release liquid is to be supplied, as needed for each copying process, between the application member and the transmission member. 1. A release liquid supply device for a toner powder image fixing device, comprising means for moving the toner powder image into and out of contact with the toner powder image fixing device.