JPH0327076A - Fixing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fixing device, and particularly to a fixing device using a heating roller.

[Prior Art] Conventionally, in electrophotographic copying machines, electrostatic printers, etc., a toner image formed on a photoreceptor as a latent image carrier is transferred onto a recording material by a fixing roller that applies heat or pressure. The image is fixed by a fixing device having a. In this type of fixing device, a release agent such as silicone oil is applied to the fixing roller in order to prevent the toner image from being offset to the fixing roller and to make it possible to easily peel off the transfer paper from the fixing roller. It is common practice to apply sex oil.

As a means for applying such oil, a first conventional example shown in FIG. 6 is known. In the figure, silicone oil l contained in an oil tank 2 is sucked up by a bomb 3 through a supply pipe 4 and sent to a nozzle 6 via a supply pipe 5. An oil pan (hereinafter referred to as an oil van) 7 is provided below the nozzle 6, and the oil pan 7 includes a coating felt 10, which is a coating member whose upper portion is in contact with the outer peripheral surface of the fixing roller 8.
The lower part of the oil bun 7 is submerged by the support plate 11, and the oil in the oil bun 7 is sucked up by capillary action and supplied to the fixing roller 8. A pressure roller rotates in pressure contact with the fixing roller 8, and a wet cloth 1 is used to clean dirt from the fixing roller 8.
2 are also in contact. The oil pan 7 is separated by a partition plate l3 into a large chamber l4 and a small chamber l5 in which the coated felt lO is immersed.
It is divided into The oil l in the large chamber 14 dripped from the supply pipe 5 through the nozzle 6 flows across the partition plate 13 and flows into the small chamber l5. A discharge port 16 is provided at the bottom of the small chamber 15 so that the oil in the small chamber 15 can be returned to the oil tank 2.
The oil l thus circulates within the fixing device.

However, in a fixing device having the above-mentioned oil circulation mechanism inside the fixing device, even when the oil bun 7 is sufficiently filled with oil 1, the bomb 3 always continues to supply the oil 1, so the circulation frequency of the oil 1 becomes high. There was a problem that the lifespan of the battery was shortened.

Also, since the large chamber 14 near the heated fixing roller 8 is always full of oil, the fixing roller 8
There is also the problem that the heat increases the evaporation rate of the oil l in the large chamber l4, increasing the amount of oil l consumed.

Therefore, in order to solve the above problem, a second conventional example as shown in FIG. 7 was proposed. In FIG. 7, reference numeral 30 is an oil amount detection means equipped with a float 31 as a floating member provided in the fixing device, and the large chamber 14 is centered around the support shaft 32.
It rotates as the liquid level of the oil l rises, and when the liquid level reaches a certain set level as shown in FIG. 8, it shuts off the foot sensor 33, which is a detection means. Then, a signal to stop the supply is sent to the bomb 3, and the supply of oil by the bomb 3 to the oil pan 7 is stopped.

- On the other hand, when the oil l is continuously supplied to the fixing roller 8 by the coating felt lO and the liquid level of the oil 1 in the oil bun 7 falls below the above set value, a supply start signal is sent from the photosensor 32 to the bomb 3. The oil l is sent to the oil pan 7 again.

As explained above, there are 3 levels of oil level detection in the fixing device.
By providing 0, it was possible to suppress the supply and circulation of oil 1 more than necessary, and the amount of oil 1 in oil vane 7 could always be maintained at an optimum amount.

[Problems to be Solved by the Invention] However, in the conventional example described above, as shown in FIGS. 9(a) and 9(b), when the main body of a printer or the like is installed with an inclination in the longitudinal direction of the fixing roller, oil leaks. Oil in pan 7
There was a problem that it became impossible to accurately detect the remaining amount of the battery. In other words, as shown in FIG. 9(a), even though there is sufficient oil remaining in the oil pan 7, the oil amount detection stage 30 cannot detect it due to the inclination of the liquid level. 3 to continue supplying oil. Therefore, the above-mentioned problem of oil circulation frequency occurs. In addition, in FIG. 9(b), inside the oil pan 7,
Even though there is only a little oil, the oil amount detection means 30
Since the presence of oil is detected based on the slope of the liquid level and the supply of oil is stopped, the amount of oil impregnated in the coating felt 10 decreases, resulting in uneven coating on the longitudinal surface of the fixing roller 8 or insufficient coating. This will result in a situation like this. Therefore, the fixing roller 8 may be offset, and the gloss of the surface of the recording material (not shown) after fixing may vary in the longitudinal direction of the fixing roller 8, which may adversely affect the image.

The present invention accurately detects the remaining amount of oil even when the main body of an electrophotographic device or the like is tilted in the longitudinal direction of the fixing roller.
It is an object of the present invention to provide a fixing device equipped with a supply device that supplies an appropriate amount of oil.

[Means for Solving the Problems] According to the present invention, the above object includes: an oil pan extending in the longitudinal direction of the fixing roller and disposed opposite to the fixing roller; In the fixing device, the fixing device includes an applicator that uniformly applies oil by slidingly contacting the longitudinal surface of the fixing roller, and an oil amount detection means that detects the amount of oil in the oil stopper. The detection means includes a detection means provided at a fixed position, a floating member having a predetermined length in the longitudinal direction floating on the oil, and a detection plate attached to the floating member, the detection plate is achieved by being attached so that it can be moved up and down (as well as up and down along the support axis) about a support shaft provided on the support member of the detection means at a central position in the longitudinal direction of the oil pan. Ru.

[Function] According to the present invention, the oil amount detection means has a floating member floating on the oil and a detection plate attached to the floating member, and the detection plate moves against the support shaft as the oil level increases or decreases. The oil amount is detected by moving up and down along the line to shut off the detection means. In addition, since the floating member has a predetermined length in the longitudinal direction of the oil pan, it receives buoyancy so as to follow the inclination of the oil liquid level, and detects the inclination by vertical movement around the support shaft. The amount of oil is detected by accurately transmitting the oil to the plate and blocking the detection means at the end of the detection plate.

[Embodiment] Next, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4 of the accompanying drawings. Note that parts common to the conventional device are given the same reference numerals and explanations are omitted. In FIG. 1, reference numeral 20 denotes oil amount detection means, including a foot sensor 2l which is a detection means provided at a fixed position, a float 22 which is a floating member floating on the oil l, and a detection device attached to the float 22. It is equipped with a plate 23. The detection plate 23 is connected to a support shaft 25 provided on a support member 24 at a longitudinally central position of the oil pan 7, as shown in FIG.
It is installed at. Further, the detection plate 23 has an elongated hole 26 formed therein, and can rotate around the support shaft 25 (arrow A in FIG. 2).
It is also possible to move up and down along the arrow B (arrow B in FIG. 2).

Next, the operation of the apparatus of this embodiment as described above will be explained using FIGS. 2 to 4. First, in the horizontal case as shown in Fig. 2, that is, in the normal installation state, when oil l is supplied to the oil pan 7 and the liquid level rises,
The detection plate 23 also rises along the length 26, and when the liquid level reaches a certain set appropriate level, the detection plate 23 shuts off the float sensor 2l, and a supply stop signal is sent from the float sensor 21 to the bomb 3. The supply of supplies sent to them will be stopped.

At this time, if the number of copies that consume oil l after the oil supply stop signal is output from the oil sensor 2l until the next oil l supply signal is output is M, then after the oil l supply is stopped, M copies will be made. After the oil 1 is removed, the oil 1 will be supplied to the oil bun 7 again. The above operations are repeated so that an appropriate amount of oil 1 is always kept in the oil bun 7.

Furthermore, as shown in Fig. 3, even if the main body is installed tilted by an angle θ1 and the oil bun 7 is tilted in its longitudinal direction, the float 22 receives buoyancy and rotates around the support shaft 25, reaching the liquid level. On the other hand, since the detection plate 23 can be kept horizontal and moved up and down, the oil amount can be detected at an appropriate level taking into account the above-mentioned inclination.

Furthermore, as shown in Fig. 4, the main body is tilted at an even larger angle θ.
2 (〉θ1), even if the oil pan 7 is tilted in the longitudinal direction, the detection plate 23 can be rotated while the float 22 remains horizontal with respect to the tilted liquid level, and the detection plate 23
Since the protrusion 27 formed in the oil valve 27 blocks the foot sensor 21, the oil amount can be appropriately controlled. Since the oil amount can be accurately detected even in the tilted state as described above, it is possible to suppress the oil circulation frequency from increasing unnecessarily. This arrangement enables highly accurate detection, and prevents uneven coating due to unevenness of oil in the longitudinal direction of the oil bun 7, as shown in FIG. 11(b).
Problems such as insufficient coating have been resolved. In addition, the number of sheets of recording material consumed for the predetermined consumption amount of oil as described above (M
If the relationship between the main body and the main body is known, it would be possible to issue a warning that the main body is tilted in the state shown in Fig. 3 and when no oil supply signal is output after copying M sheets.

Next, a second embodiment of the present invention will be described using FIG. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof is omitted.

In this embodiment, the detection plate 23 is attached to the float 22 with an inclination in a plane perpendicular to the axis of the fixing roller.
It is distinctive in that it is placed at a position away from the fixing roller 8. With such a configuration, the fuser sensor 21 is placed at a sufficient distance from the fixing roller 8, so that false detection due to high heat emitted from the fixing roller 8 can be avoided.
Less susceptible to negative effects such as failure. Therefore, the reliability of the oil amount detection means is improved. [Effects of the Invention] As explained above, according to the present invention, certain effects can be achieved. Since the amount of oil can always be accurately detected regardless of whether or not the main body of the device is tilted in the longitudinal direction of the roller, the frequency of oil circulation can be reduced to extend the life of the oil and improve consumption efficiency. Furthermore, by always keeping the oil applied to the fixing roller optimal, it is possible to maintain good images.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a cross-sectional view showing a schematic configuration of the apparatus according to the first embodiment of the present invention, Fig. 2 is a front view showing the vicinity of the oil bun of the apparatus shown in Fig. 1, and Fig. 3 is the same as that shown in Fig. 1. Figure 4 is a front view showing the area around the oil pan when the device is tilted at an angle θ■, Figure 4 is a front view showing the area around the oil pan when the unit is tilted at an angle θ2, and Figure 5 is the main body. FIG. 6 is a cross-sectional view showing the schematic structure of the second conventional device, FIG. 7 is a cross-sectional view showing the schematic structure of the second conventional device. Figure 8 is a front view of the area around the oil van shown in Figure 7, Figure 9 (a) is a front view of the area around the oil pan shown in Figure 7 when the device is tilted to the right, and Figure 9 (b) FIG. 7 is a front view showing the area around the oil van when the device is tilted to the left. 7・・・・・・・・・・・・Oil dish (Sai Iruban) 8
......Fuser roller 20...
・・・・・・Oil amount detection means 2l・・・・・・・・・
...Detection means (foot sensor) 22...
...Floating member (float) 23...
...Detection plate 24... Support member 25...
・・・・・・Support shaft

Claims (1)

[Scope of Claims] An oil pan extending in the longitudinal direction of the fixing roller and disposed opposite to the fixing roller, and an oil pan extending from the inside of the oil pan and sliding uniformly on the longitudinal surface of the fixing roller. In the fixing device, the fixing device includes an application member that contacts to apply oil, and an oil amount detection device that detects the amount of oil in the oil pan, wherein the oil amount detection device is a detection device provided at a fixed position. , comprising a floating member having a predetermined length in the longitudinal direction floating on the oil, and a detection plate attached to the floating member, the detection plate detecting the detection at a central position in the longitudinal direction of the oil pan. 1. A fixing device, characterized in that the fixing device is attached so as to be movable up and down about a support shaft provided on a support member of the means, and to be movable up and down along the support shaft.