JPS6281682A - Tehrmal fixing device - Google Patents

Abstract

PURPOSE:To prevent thermal change of recording paper, make the device compact and heighten efficiency of recording operation by providing a curl restraining device in the direction of width of recording paper and a blasting device that supplies cooling wind to the gap between a thermal fixing roller and recording paper in the mechanism of a continuous recording device. CONSTITUTION:Recording paper sent out from a paper hopper 11 is transferred continuously by a transferring device 8 and received in a paper receiving stack being held between a heating roller 14 and a pressing roller 15. When the paper is stopped once and exposed to a high temperature part, the state of holding of the heating roller 14 and pressing roller 15 is released, and at the same time, the paper is held between curl restraining members X, and cold wind is sent between the heating roller 14 and the paper P from a blasting device 21. By this way, generation of thermal change in the paper during waiting, the distance from the hightemperature pat is minimized, the device is made compact and time required for restarting is shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a recording device such as a laser beam printer that performs recording using continuous recording paper, by heating an unfixed image on the recording paper. The present invention relates to a heat fixing device for fixing. More specifically, a pair of heat fixing rollers are provided to sandwich the continuous recording paper, and when the continuous recording paper is being conveyed, the pair of heat fixing rollers clamps the continuous recording paper and conveys the continuous recording paper. The present invention relates to a heat fixing device including a paper nipping mechanism that releases the nipping when the paper stops.

[Conventional technology]

Continuous recording paper is used in various printers and is capable of high-speed recording operations. In a heat fixing device of a recording apparatus using such continuous recording paper, during recording operation, the continuous recording paper is held between a pair of heat fixing rollers,
The continuous recording paper is brought into contact with the high-temperature portion of the heat-fixing roller pair, and the heat-melting coloring material forming the unfixed image on the continuous recording paper is heated and fixed. When the recording operation is stopped, the continuous recording paper is released from being held between the heat-fixing roller pair in order to prevent ignition due to prolonged contact with the high-temperature part of the heat-fixing roller pair. It is common to configure the continuous recording paper to stand by separated from the high temperature portion of the pair of heating and fixing rollers.

However, in order to speed up the recording operation by conveying the continuous recording paper at high speed, it is necessary to heat the heating and fixing roller pair to an extremely high temperature in order to apply sufficient heat to the continuous recording paper during fixing. Therefore, in order to prevent the continuous recording paper from being burnt and discolored during the above-mentioned standby, the continuous recording paper must be kept quite far away from the high temperature part of the heat-fixing roller pair, and the part occupied by the heat-fixing device This increases the number of devices and prevents the device from becoming more compact.

Further, during this waiting period, the continuous recording paper is dried by the heat from the heating and fixing roller pair, and a state in which the continuous recording paper is bent toward the high temperature portion of the heating and fixing roller pair, that is, so-called curling occurs. Therefore, both edge portions of the continuous recording paper come close to the high-temperature portion of the heat-fixing roller pair, and local discoloration is likely to occur.

Therefore, conventionally, in the above-mentioned heat fixing device, the temperature of the heat fixing roller pair is controlled to be lower during standby when no recording operation is performed than during recording operation, thereby making the device more compact. It was designed to prevent the continuous recording paper from burning and discoloring while ensuring that it was not damaged.

[Problem that the invention seeks to solve]

However, in the case of the above-mentioned conventional configuration, the temperature of the heat-fixing roller pair becomes low during standby, so when the recording operation is restarted, the temperature of the heat-fixing roller pair becomes lower than that of the unfixed part on the continuous recording paper. It takes some time to reach a temperature sufficient to heat and fix the image, which may reduce the efficiency of the recording operation.

In view of the above-mentioned circumstances, an object of the present invention is to prevent discoloration of continuous recording paper due to heat from a pair of heat fixing rollers, without hindering both the downsizing of equipment and the efficiency of recording operations.

[Means for solving problems]

The characteristic configuration of the heat fixing device according to the present invention is that a curl regulating member is provided near the pair of heat fixing rollers to regulate the curling of the continuous recording paper in the width direction, and a curl regulating member is provided near the pair of heat fixing rollers and the continuous recording paper is provided between the pair of heat fixing rollers and the continuous recording paper. The reason is that a blower is provided to send cooling air to the recording paper.

[For production]

In other words, since the continuous recording paper is prevented from curling in the width direction by the curl regulating member, even if the continuous recording paper dries due to the heat from the heating and fixing roller pair, the continuous recording paper will not be able to reach the high temperature area of the heating and fixing roller pair. never come close to.

Moreover, since the continuous recording paper is cooled by the cooling air from the blower, the temperature of the heat-fixing roller pair is always maintained at a high enough temperature to apply heat to the continuous recording paper to enable fixing in a short time. However, the temperature of the continuous recording paper that is on standby does not rise to the point where it changes color.

〔Example〕

The present invention will be described in detail below based on the drawings.

FIG. 2 shows a schematic configuration of a laser beam printer which is an example of a recording device equipped with a heat fixing device according to the present invention.

According to the input recording signal, the laser light pulse-modulated and oscillated from the semiconductor laser (1) is collimated by the collimator lens (2) and reflected by one mirror surface of the polygon mirror (3) that rotates at high speed. be done. By rotating this polygon mirror (3), the tilt of the mirror surface with respect to the laser beam (Bo) changes, and accordingly, the reflected laser beam (B
, I) are scanned in the longitudinal direction of a photosensitive drum (4), which is an example of an exposure body. This laser beam (BR) is focused by an fθ lens (L) and forms an image on the photosensitive drum (4) whose surface is uniformly charged, thereby reducing the charging potential at that position. Then, as the photosensitive drum (4) rotates, the above-mentioned scanning is repeated.
An electrostatic latent image is formed on the photoreceptor drum (4).

Around the photoreceptor drum (4), there is a charging device (5) that uniformly charges the surface of the drum, an inter-image eraser (6) that erases the electric charges on areas other than the recorded area, and a photoreceptor drum (4).
A developing device (7) that attaches toner to the electrostatic latent image formed on the electrostatic latent image to make it visible, a transfer device (8) that transfers the developed image to the recording paper (P), and a device after transferring the developed image. Photoreceptor drum (
4) A main eraser (9) for erasing charges on the photoreceptor drum (4), a cleaner (10) for removing excess toner adhering to the surface of the photoreceptor drum (4), etc. are arranged in that order.

The recording paper (P) is continuous, and the paper hopper (11)
It is folded and stored. This continuous recording paper (P)
is pulled out from the paper hopper (11), and the transport roller (
lla) and comes into contact with the surface of the photoreceptor drum (4) at the transfer device (8) portion. After the developed image has been transferred, it is further transported to a heat fixing device (F
), after which the developed image is fixed, the paper is stored in a folded state in a paper stacker (13) by a pair of feed rollers (12).

As shown in FIGS. 1(a) and 1(rl), the heat fixing device (F) includes a heating roller (14) and a pressure roller (15) that are disposed opposite to each other in the conveyance path of the continuous recording paper (P). It is composed of etc.

The heating roller (14) rotating clockwise in the figure is equipped with a heater (14a) inside.
The continuous recording paper (P) passing between the rollers (14) and (15) is heated by the operation a). On the other hand, the pressure roller (15) is rotatably supported by a casing (16) that is rotatable around the axis (Pl). Then, the coil spring (17) locked to one end of this casing (16) is attached to the cam member (1).
8) It is locked to the eccentric bottle (18a) installed upright. The coil spring (17) and the cam member (18) constitute a paper holding mechanism (PHM) that switches between a state in which the continuous recording paper (P) is held and a state in which it is not held.

That is, when the recording operation is performed and the continuous recording paper (P) is being conveyed, the eccentric bin (18a) is moved to the position shown in FIG.
As shown in a), the coil spring (17) is in the extended position.

In this state, the pressure roller (15) is pressed against the heating roller (14) by the biasing force of the coil spring (17), and the continuous recording paper (P) being conveyed is pressed against the heating roller (14).
) is designed to be held while being pressed against the Therefore, by the cooperative work of both rollers (14) and (15), the toner forming the unfixed image on the continuous recording paper (P) is heated and melted and fixed on the continuous recording paper (P). .

Furthermore, when the recording operation is not performed and the continuous recording paper (P) is not being conveyed, the eccentric bin (18a) is moved as shown in FIG.
As shown in TI), the coil spring (17) is in the position to be compressed. In this state, the pressure roller (15) is separated from the heating roller (14), and the state in which the continuous recording paper (P) is held between the rollers (14) and (15) is released.

In this state, it is necessary to wait until the next recording operation starts, but the temperature of the portion of the continuous recording paper (P) facing the heating roller (14) rises due to the heating by the heating roller (14). . Further, the continuous recording paper (P) is heated and dried, and in particular, both edges of the continuous recording paper (P) are turned over toward the heating roller (14) and come close to the high temperature surface of the heating roller (14). Therefore, there is a risk that the continuous recording paper (P) may change color.

Therefore, in the heat fixing device (F) of this laser beam printer to which the present invention is applied, a heat fixing roller pair ()I consisting of a heat roller (14) and a pressure roller (15)
A curl regulating member (X) for regulating the curling of the continuous recording paper (P) in the width direction is provided near the continuous recording paper (P), and continuous recording is performed in the space between the heating roller (14) and the continuous recording paper (P). A blower (21) is provided to send cooling air to the paper (P).

In other words, the curl regulating member (X) prevents the continuous recording paper (P) on standby from coming close to the surface of the heating roller (14), and the continuous recording paper on standby is prevented from coming close to the surface of the heating roller (14) by the cooling air from the blower (21). This is to prevent the temperature of (P) from rising. Therefore, even if the surface temperature of the heating roller (14) during standby is made considerably high, the continuous recording paper (P) does not need to be separated from the surface of the heating roller (14) very much. ) can be prevented from discoloring.

The curl regulating member (X) is provided on the heating roller (14) side, and rotates around the axis (P2) in synchronization with the rotation of the pressure roller (15).
) is configured to rotate around the curl control device (19
) and this curl regulating tool (
It consists of a guide plate (20) and the like arranged opposite to the guide plate (19).

As shown in FIG. 4, the curl regulating device (19) is a cylindrical device in which both ends of a plurality of bent steel wires (19a) are connected to each other by plate members (19b) and (19c), respectively. . As shown in Fig. 3 (a) to c) and Fig. 4, the plate member (19
c) and the bracket (
23) are pivotally connected by a pair of links (24). At one end of this Rondo (22), an operating arm (
25) is fixed, and furthermore, this operating arm (25) is fixed.
5) is in contact with a cam member (27) attached to the rotary solenoid (26).

The curl regulating device (19) is urged away from the continuous recording paper (P) by a spring (28) attached to the bracket (23) described above.

When the heat fixing operation accompanying the recording operation is being performed, as shown in Fig. 3 (a), the rotary solenoid (26)
is in operation, and the curl regulating device (19) is separated from the continuous recording paper (P) by the biasing force of the coil spring (28). Therefore, at this time, continuous recording paper (
P) does not become a resistance when being transported.

On the other hand, when no recording operation is being performed, FIG.
), the rotary solenoid (26) is not operating, and the cam member (27) rotates clockwise in the figure due to the return torque of the solenoid.

As a result, the operating arm (25) is pushed up, the curl regulating device (19) rotates around the axis (P2), and the continuous recording paper (P) is sandwiched between it and the guide plate (20). . Therefore, it is possible to prevent the continuous recording paper (P) that has been dried by the heat from the heating roller (14) from curling and coming close to the surface of the heating roller (14).

In addition, when setting the continuous recording paper (P), the rotary solenoid (26) is activated to move the curl regulating device (19) from the conveyance path of the continuous recording paper (P) as shown in Figure 3 (c). It is constructed so that it can be pulled apart.

In addition, the blower (21) is shown in Figure 1 (a) or 0),
And, as shown in FIG. 5, a sirocco fan (21a)
, a casing (
21b) etc. This casing (21b)
The air outlet is directed between the heating roller (14) and the continuous recording paper (P). Furthermore, as shown in Figure 5,
A plurality of wind direction regulating fins (21c) are erected near the air outlet of the casing (21b) to regulate the direction of the cooling air sent from the sirocco fan (21a) at both end edges of the continuous recording paper CP. It is. In other words, the heating roller (1
Since the continuous recording paper (P) that has received the heat from step 4) tends to curl at both ends thereof, cooling of these parts is concentrated.

In Fig. 1 (a) and (■), (29) is a guide plate that guides the continuous recording paper (P) to the heat fixing roller pair (HR), and (30) and (31) are the guide plates that guide the continuous recording paper (P). ) are buffer arms and coil springs that provide tension.

In the previous embodiment, the curl regulating member (X) was constructed from a cylindrical curl regulating member (19), a guide plate (20), and the like. Instead of this, the following modification is also possible.

(1) As shown in Figure 6 (a), continuous recording paper (P)
The curl regulating member (X) is composed of a flat curl regulating device (19) that spans the entire width of the curl regulating device (19) and a guide plate (20).

2> Since curls often occur at both edges of the continuous recording paper (P), as shown in Fig. 6 (11), the flat curl control device (19) is Cut out the parts other than the parts corresponding to both end edges.

<3> For the same reason as in the above-mentioned 2), a pair of flat plates are provided as curl regulating devices (19) at both end edges of the continuous recording paper (P), as shown in FIG. 6(C).

4〉As shown in Fig. 6 (=), from the driven guide roller (32) and the flat curl regulating device (19),
It constitutes a curl regulating member.

5> As shown in Figure 6 (N), use the curl regulating tool (19
), the surface that contacts the continuous recording paper (P) is made to have an uneven shape such as a waveform.

<6> As shown in Figure 6 (f), use the curl control tool (19
) is provided with a cushioning member (33) such as felt on the surface that comes into contact with the continuous recording paper (P) to prevent damage to the continuous recording paper (P) or staining of recorded characters, images, etc. .

In addition to what has been described above, the specific configuration of the curl regulating member (x) can be changed as appropriate. For example, a curl regulating member (
If the structure has a small sliding resistance with the paper, such as X), the curl regulating device (19) may not be rotated and may be kept in constant contact with the continuous recording paper (P). In this case, the paper holding mechanism (PHM) is configured to swing the pressure roller (15) when the conveyance of the continuous recording paper (P) is stopped, and instead of swinging the pressure roller (15). It is sufficient if the configuration is such that one side is swung.

In the previous embodiment, the curl regulating member (X) was provided on the lower side of conveyance of the continuous recording paper (P) than the pair of heat fixing rollers (HR). (X) may be provided on the upper side of the conveyance side than the heat-fixing roller pair (HR), and furthermore, a curl regulating member (X) may be provided before and after the heat-fixing roller pair (HR). .

Further, in the previous embodiment, the blower (21) was provided on the upper side of the conveyance of the continuous recording paper (P) than the pair of heat fixing rollers (IIR) and on the side of the heating roller (14). Instead of this, similarly to the above-mentioned modification of the curl regulating member (X), the blower (21) may be provided on the lower side of the conveyance side than the heat-fixing roller pair (HR), or
It may be provided before or after. Sarabanko, blower (21
) is provided on the heating roller (14) side,
It may be on the pressure roller (15) side or both.

The heat fixing device (F) according to the present invention is applicable not only to the laser beam printer described in the previous embodiment, but also to various printers that use continuous recording paper (P) and record by heat-fixing a heat-fusible coloring material. can do.

〔Effect of the invention〕

As described above, the heat fixing device according to the present invention has the following features:
The curl regulating member prevents the continuous recording paper on standby from coming close to the high temperature part of the pair of heating and fixing rollers, and also prevents the temperature of the continuous recording paper on standby from rising due to the cooling air from the blower. be. Therefore,
Even if the temperature of the heat-fixing roller pair during standby is raised considerably, continuous recording paper can be prevented from discoloring without having to separate the continuous recording paper from the high-temperature part of the heat-fixing roller pair. It can be done.

As a result, by reducing the distance between the continuous recording paper and the high-temperature part of the heat-fixing roller pair during standby, the device can be made more compact, and the temperature of the heat-fixing roller pair can be maintained at a high temperature even during standby. By doing so, the waiting time when the recording operation is restarted can be reduced, and the recording operation can be performed efficiently.

[Brief explanation of drawings]

The drawings show an embodiment of the heat fixing device according to the present invention.
Figures (a) and (b) are schematic cross-sectional views of the heat fixing device part of a laser beam printer. Fig. 2 is a schematic sectional view of the laser beam printer, Fig. 3 (a) or c) is a side view of the curl regulating member, and Fig. 3 (a) shows a state in which the heat fixing operation is not performed. 3(If) shows the state where the heat fixing operation is not performed, FIG. 3(C) shows the state where continuous recording paper is set, FIG. 4 is a perspective view of the curl restrictor, and FIG. The figure is a perspective view of the blower, and FIGS. 6(a) and 6(b) are schematic perspective views showing other embodiments of the curl regulating member, respectively. (P)... Continuous recording paper, (HR)...
・Pair of heating fixing rollers, (PIIM)...Paper holding mechanism, (X)...Curl regulating member, (21)
······Blower.

Claims (1)

[Claims] A pair of heat fixing rollers are provided to sandwich the continuous recording paper, and the pair of heat fixing rollers sandwich the continuous recording paper while the continuous recording paper is being conveyed, and when the continuous recording paper is stopped being conveyed. In a heat fixing device equipped with a paper holding mechanism for releasing this holding, a curl regulating member is provided near the pair of heat fixing rollers to prevent curling of the continuous recording paper in the width direction, and a curl regulating member is provided near the pair of heat fixing rollers to prevent curling of the continuous recording paper in the width direction. A heat fixing device equipped with a blower that blows cooling air between the continuous recording paper and the paper.