JP2000242129A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to shorten the rise time of a fixing device. SOLUTION: This fixing device 1 comprises a heat source 17 for heat generating operation, an air blowing means 18 for blasting air to the heat source 17 to produce warm air and blowing this warm air to printing paper to be transported, a heat source temperature detecting means 30 for detecting the temperature of the heat source 17, and a control means 20 for turning on the air blowing means 18 when the heat source 17 temperature detected by the heat source temperature detecting means 30 reaches a predetermined temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an image forming apparatus using an electrophotographic technique,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an orthogonal transfer type image forming apparatus that presses a toner image onto a print sheet and transfers the toner image in a direction orthogonal to a conveying direction of a print sheet as a recording medium.

[0002]

2. Description of the Related Art In recent years, toner-type image forming apparatuses capable of forming clear images with excellent resolution, such as laser printers, have become widespread. As an image forming apparatus of such a toner type, the applicant of the present invention has disclosed in Japanese Patent Application No. 7-328600 the orthogonal image forming apparatus in which a toner image carrier is moved in a direction orthogonal to a conveying direction of a printing paper to transfer a toner image. A transfer type image forming apparatus was proposed.

[0003] A conventional orthogonal transfer type image forming apparatus will be described below.

The orthogonal transfer type image forming apparatus has a closed loop belt-shaped toner image carrier, and is supported by a toner image carrier roller and a transfer opposing roller to rotate around. Around the toner image carrier, a toner image carrier cleaning means, a static eliminator, a charger, an exposure device, and a developing device are sequentially arranged in the rotation direction, and the toner is stored inside the developing device. . The printing paper is supported on a transfer plate, and is transported by a printing paper transport roller in a direction perpendicular to the rotation direction of the toner image carrier.

Next, the operation of the orthogonal transfer type image forming apparatus having the above-described configuration will be described.

When an image forming operation is instructed, the toner image carrier roller and the transfer opposing roller rotate, and the toner image carrier starts to rotate. After the surface of the toner image carrier is charged by the charger, an electrostatic latent image is formed on a portion charged by the laser light emitted from the exposure device.

When the developing roller of the developing device comes into contact with the toner image carrier, the electrostatic latent image is developed by the toner attached to the surface of the developing roller to form a toner image.

When the formation of the toner image is completed in this manner, the toner image carrier is pressed against the printing paper by the transfer opposing roller, and the toner image on the toner image carrier is transferred onto the printing paper.

When the transfer of the toner image is completed, the print paper transport roller rotates to transport the print paper on which the image is formed. Thereafter, the toner image is fixed on the printing paper by the fixing device, and is discharged to a discharge tray (not shown). on the other hand,
The toner remaining on the portion of the toner image carrier on which the toner image has been transferred is removed by the toner image carrier cleaning means, and then the charge on the toner image carrier is eliminated by the charge eliminator.

FIG. 6 is a perspective view showing a peripheral structure of a fixing device in a conventional orthogonal transfer type image forming apparatus.

As shown in FIG. 6, a fixing device 1 for fixing a toner image to printing paper has a heat source 17 and a driving motor 19.
And a blowing means 18 such as a cross-flow fan which is driven to rotate to blow air to the heat source 17. Then, the printing paper 14 is conveyed so as to traverse the flow path of the air starting from the blowing means 18 and passing through the heat source 17. In addition, both sides of the air flow path have heat insulation properties,
A guide plate 16 for guiding the air from the blowing means 18 to the printing paper 14 is provided.

Therefore, the air from the blowing means 18 is
As shown by a thick arrow in the drawing, the sheet is heated by the heat source 17 and is sprayed on the printing paper 14 while the diffusion is prevented by the guide plate 16.

Downstream of the heat source 17, a temperature detecting means 3 for detecting the temperature of the hot air heated by the heat source 17 is provided. Then, based on the temperature of the hot air detected by the temperature detecting means 3, the heater is turned on / off so that the temperature of the hot air becomes a predetermined temperature.

Below the fixing device 1, a conveyance guide 2 for passing a printing paper 14 between the fixing device 1 and the fixing device 1 is disposed.

In such a fixing device 1, when the printing operation is started, the blowing means 18 and the heat source 17 are both turned on, and the wind sent by the blowing means 18 hits the heat source and becomes hot air. The temperature of the hot air is monitored by the temperature detecting means 3. Then, when the temperature of the hot air reaches a predetermined value,
The printing paper 14 on which unfixed toner is loaded is conveyed into the fixing device 1. At this time, the toner is heated and melted by the hot air blown, and is fixed on the printing paper 14. During this time, the heat source 17 is turned on and off so that the hot air temperature becomes a predetermined value.

[0016]

However, the above-described fixing technique has the following problems.

That is, in the fixing device in the conventional orthogonal transfer type image forming apparatus, since the honeycomb structure or the like is arranged at the outlet of the warm air in order to increase the heat capacity, the fixing device is turned on after the heat source is turned on. It takes a long time to stand up (about 1 minute), and it takes a long time to start printing. At this time, the heat source and the blowing means are simultaneously turned on.

Accordingly, an object of the present invention is to provide a fixing device capable of shortening the rise time of the device.

[0019]

In order to solve this problem, a fixing device according to the present invention transfers a toner image on a toner image carrier onto a recording medium by pressing the toner image onto the recording medium in a direction perpendicular to the conveying direction of the recording medium. A fixing device mounted on an image forming apparatus and fixing a toner image transferred to a recording medium to the recording medium, the heat source performing a heat generating operation, and blowing hot air to the heat source to generate warm air, which is conveyed. A blower that sends the warm air toward the recording medium, a heat source temperature detector that detects the temperature of the heat source, and a blower that is turned on when the temperature of the heat source detected by the heat source temperature detector reaches a predetermined temperature. And a control means.

Further, the fixing device of the present invention is mounted on an image forming apparatus for transferring a toner image on a toner image carrier by pressing the toner image onto the recording medium in a direction perpendicular to the conveying direction of the recording medium, and transferring the toner image onto the recording medium. A fixing device for fixing the toner image to the recording medium, a heat source for generating heat, and blowing means for blowing hot air to the heating source to generate hot air and sending the hot air toward the conveyed recording medium. And a timer for measuring a heat source rise time until the temperature of the turned on heat source reaches a predetermined temperature, and a control means for turning on the blowing means when the heat source rise time is counted by the timer. is there.

[0021] Thus, the operation of raising the temperature of the heat source is not hindered by the wind from the blowing means, so that the rise time of the apparatus can be shortened.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is mounted on an image forming apparatus for transferring a toner image on a toner image carrier by pressing the toner image onto a recording medium in a direction orthogonal to the conveying direction of the recording medium. A fixing device for fixing the toner image transferred to the recording medium to the recording medium, the heat source performing a heat generation operation, and blowing air to the heat source to generate warm air, and direct the recording medium toward the conveyed recording medium. Blowing means for sending the hot air, heat source temperature detecting means for detecting the temperature of the heat source, and control means for turning on the blowing means when the temperature of the heat source detected by the heat source temperature detecting means reaches a predetermined temperature. Fixing device,
Since the wind from the air blowing means does not hinder the heat-up operation of the heat source, there is an effect that the rise time of the apparatus can be shortened.

According to a second aspect of the present invention, there is provided an image forming apparatus mounted on an image forming apparatus for transferring a toner image on a toner image carrier by pressing the toner image onto the recording medium in a direction orthogonal to the conveying direction of the recording medium. Is a fixing device for fixing the toner image transferred to the recording medium on the recording medium, and generates a hot air by blowing air to the heat source, and generates the hot air toward the recording medium to be conveyed. A fixing device comprising: a blowing unit that sends air; a timer that measures a heat source rising time until the temperature of the turned on heat source reaches a predetermined temperature; and a control unit that turns on the blowing unit when the heat source rising time is counted by the timer. This is an apparatus, which has an effect that the rising time of the apparatus can be shortened because the operation of raising the temperature of the heat source is not hindered by the wind from the blowing means.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a schematic view showing an image forming apparatus of an orthogonal transfer system according to an embodiment of the present invention, FIG. 2 is a perspective view showing a main part of the image forming apparatus of FIG. 1, and FIG. FIG. 4 is an explanatory diagram showing a transfer operation of the image transfer device, FIG. 4 is a schematic diagram showing a structure of a fixing device attached to the image forming device of FIG. 1, and FIG. 5 is a block diagram showing a control system of the fixing device of FIG. .

As shown in FIG. 1, in the image forming apparatus of the orthogonal transfer type according to the present embodiment, the toner image carrier 4 which is a closed loop belt-shaped photosensitive member having an organic photoconductive material coated on the surface thereof is used. The belt is tuned and supported by the transfer opposing roller 7, the toner image carrier roller 5, the displacement roller 6, and the sandwiching roller 8, and rotates in the direction of arrow A.

Around the periphery of the toner image carrier 4, a charger 9 for uniformly charging the surface of the toner image carrier 4 in the direction of its rotation, and an exposure light beam on the charged toner image carrier 4 An exposure device 13 for irradiating the latent image 13a to form an electrostatic latent image corresponding to image data, and applying toner to a latent image portion of the toner image carrier 4 formed by the exposure device 13 to visualize the electrostatic latent image Developing unit 10, a toner image carrier cleaning unit 11 for removing residual toner remaining on the toner image carrier 4 after transfer, and a static eliminator 12 for removing residual potential on the toner image carrier 4 are sequentially arranged. Have been.

The developing device 10 contains toner 10a, and a developing roller 10b for attaching the toner 10a to the electrostatic latent image formed on the toner image carrier 4.
Is provided.

A printing paper (recording medium) 14 is supported on a transfer plate 15, and as shown in FIG. 2, a printing paper transport roller (not shown) for transporting the printing paper 14 causes the toner image carrier 4 to move. Is conveyed in a direction (arrow B direction) perpendicular to the direction in which the image rotates (arrow A direction).

As shown in FIG. 4, the fixing device 1 for fixing the toner image 10c to the printing paper 14 is driven by a heat source 17 for generating heat and a driving motor (not shown). And a blowing means 18 such as a cross flow fan for blowing air. Then, the printing paper 14
Is transported so as to cross the flow path of the air that has started from the blowing means 18 and passed through the heat source 17.

On both sides of the air flow path, guide plates 16 having heat insulating properties and guiding the air from the blowing means 18 to the printing paper 14 are arranged.

On the downstream side of the heat source 17, a rectifying means 3 composed of a honeycomb laminated body, which is surrounded by the guide plate 16 and sends a uniform flow of hot air to the printing paper 14.
2 are provided.

Therefore, the air from the blowing means 18 is
As shown by the arrow in the figure, while being prevented from being diffused by the guide plate 16, it is heated by the heat source 17 and then passes through the rectifying means 32 and is sprayed on the printing paper 14.

As the heat source 17, a light irradiation type such as a halogen lamp, a xenon lamp, a mercury lamp, and an infrared heater lamp, and a resistance heating type using a nichrome wire or the like are used.

In the vicinity of the heat source 17, a heat source temperature detecting means 30 for detecting the temperature of the heat source 17 is provided. Further, a temperature detection unit 3 that detects the temperature of the hot air heated by the heat source 17 is provided downstream of the rectification unit 32. Then, based on the temperature of the hot air detected by the temperature detecting means 3, the heater is turned on / off so that the temperature of the hot air becomes a predetermined temperature.

Below the fixing device 1, a transport guide 2 for passing a printing paper 14 between the fixing device 1 and the fixing device 1 is provided. In this embodiment, although the fixing device 1 and the transport guide 2 are shown as separate bodies, the transport guide 2
May be included in the fixing device 1.

According to such a fixing device 1, the printing paper 14 to which the toner has been transferred is transported on the transport guide 2, and
At this time, the toner is heated and melted by the hot air blown, and is fixed on the printing paper 14. In addition, the blowing means 18
It is always on during the fixing operation.

Here, as shown in FIGS. 4 and 5, an MPU (microprocessor unit) 2 serving as control means
0 controls the entire image forming apparatus while reading out a program stored in the ROM 21 in advance. The MPU 20 controls the operation of the blower 18 via a fan driver (drive circuit) 25 and the temperature of the heat source 17 via a heater driver (drive circuit) 22. Further, the warm air and the temperature of the heat source 17 in the analog signals detected by the temperature detecting means 3 and the heat source temperature detecting means 30 are converted into digital signals by the A / D converter 24 and input to the MPU 20. Note that M
A timer 31 is connected to the PU 20. The timer 31 counts a predetermined time and returns a signal to the MPU 20.

Next, the operation of the orthogonal transfer type image forming apparatus having the above configuration will be described.

When the control section (not shown) of the image forming apparatus instructs the start of the image forming operation, the image data is written in the image data storage memory, and the toner image carrier roller driving means (not shown). Transfer opposing roller 7, toner image carrier roller 5, displacement roller 6, and nipping roller 8
Rotates, and the toner image carrier 4 starts to rotate in the direction of arrow A.

The surface of the toner image carrier 4 is charged to, for example, -600 V by the charger 9 in accordance with the content of the image to be formed.
After being uniformly charged to the extent, the image data storage memory 12
An electrostatic latent image is formed on the charged portion by the exposure light beam 13a emitted from the exposure device 13 in accordance with the data read from the device.

When the portion of the toner image carrier 4 where the electrostatic latent image is formed reaches the position of the developing device 10, the developing roller 10b disposed in the developing device 10 is driven by developing roller driving means (not shown). It rotates and comes into contact with the toner image carrier 4. As a result, the toner image carrier 4 is moved to the developing roller 10b.
The electrostatic latent image is developed by the toner 10a attached to the surface of the developing roller 10b while being moved while being nipped between the nipping roller 8 and the toner image 10c on the toner image carrier 4.
Is formed.

By such an operation, the toner image 1 in the range corresponding to the image forming area L of the printing paper 14 shown in FIG.
When 0c is formed on the toner image carrier 4, the transfer of the toner image 10c from the toner image carrier 4 onto the printing paper 14 is performed.

That is, the transfer of the toner image 10c is performed by first setting the leading end p1 of the toner image 10c formed on the toner image carrier 4 to the end p2 of the image forming area of the printing paper 14.
When the position is substantially the same as the above, the rotations of the toner image carrier roller 5, the displacement roller 6, and the transfer opposing roller 7 are stopped, and the rotation of the toner image carrier 4 is stopped.

Next, the paper transport roller is rotated by paper transport means (not shown), and the printing paper 14 is moved in the direction of arrow B perpendicular to the rotation direction of the toner image carrier 4 as shown in FIG. 15 to a predetermined position.

When the transfer of the printing paper 14 is completed, the transfer facing roller 7 is moved by the transfer facing roller driving means (not shown) from the transfer start position p3 to the transfer end position p4 in the direction of arrow C shown in FIG. And the displacement roller 6 moves in the direction of arrow D so as to keep the tension of the toner image carrier 4 constant with the movement of the transfer opposing roller 7.

During the parallel movement of the transfer opposing roller 7,
The toner image carrier 4 is sequentially pressed against the printing paper 14 by the transfer opposing roller 7. At this time, by applying a reverse bias to the toner image to the entire transfer plate 15, the toner image 10c on the toner image carrier 4 is attracted to the transfer plate 15 side, and the printing paper 14 on the transfer plate 15 Is transferred to

When the transfer of the toner image 10c is completed in this way, the printing paper transport roller 11 rotates again, and the printing paper 14 is moved by a distance corresponding to the effective transfer width M of the toner image carrier 4 shown in FIG. Is transported in the direction of arrow B, and the toner image carrier 4 rotates.

Then, again, the leading end of the toner image 10 c on the toner image carrier 4 is moved to the image forming area L of the printing paper 14.
Is substantially the same as the end of the toner image 10c, the toner image 10c is transferred onto the printing paper 14 in the same manner as described above. At this time, the transfer opposing roller 7 moves from the previous transfer end position p4 in the direction opposite to the arrow C direction shown in FIG. 3, and moves in parallel along the printing paper 14 to the previous transfer start position p3.

After the transfer, the printing paper 14 is transported in the direction of arrow B by the same distance as the effective transfer width M shown in FIG. Further, the toner remaining on the portion of the toner image carrier 4 where the toner image 10c has been transferred is removed by the toner image carrier cleaning means 11, and thereafter, the charge on the toner image carrier 4 is eliminated by the charge eliminator 12. You.

As described above, the formation of the toner image 10 c on the toner image carrier 4 and the formation of the toner image 10
The transfer of c and the paper conveyance are repeated, and the printing paper 14 reaches the fixing device 1.

Here, in the fixing device 1 shown in FIG. 4, when the printing operation is started, the heat source 17 is turned on, and at the same time, the temperature detected by the heat source temperature detecting means 30 is monitored. Then, when it is detected that the temperature has reached the predetermined temperature, the blowing means 18 is turned on. Next, the temperature of the hot air rectified by the rectification unit 32 is detected by the temperature detection unit 3, and the heat source 17 is turned on and off so as to reach a predetermined temperature.

As described above, in the present embodiment, the heat source 17
And the blower 18 are not turned on at the same time, but the blower 18 is turned on after the temperature of the heat source 17 reaches a predetermined temperature. That is, when the blower 18 is turned on simultaneously with the heat source 17, the heat from the blower 18
Is hard to warm up, and thus the temperature of the warm air is hard to rise. On the other hand, if the temperature of the heat source 17 is first raised and then the blowing means 18 is turned on to start blowing, the wind from the blowing means 18 does not hinder the temperature rising operation of the heat source 17. Can blow hot air.

Here, the wind near the heat source 17 is
The temperature of the heat source 17 must be set in anticipation of the fact that the temperature drops during the flow to the outlet located at the rear of 2. In this case, there is a problem in the time when the temperature of the heater constituting the heat source 17 rises. Taking a nichrome wire as an example, at 500 W, the temperature generally reaches about 600 ° C. in a few seconds, and the rise in this portion is almost negligible. According to the present inventor, the rise time of the warm air temperature in such a fixing device 1 is about 30 seconds, which is about half of the conventional time.

The temperature of the heat source 17 can be similarly shortened by using the timer 31 without monitoring. That is, the rise time of the heat source 17 is measured in advance by an experiment, and the value is incorporated in the program. Then, when the fixing device 1 is started up, the heat source 17 is first turned on, as in the case described above. Then, the value incorporated in the program is counted by the timer 31. When the heat source rise time is counted, the blowing means 18 is turned on. The subsequent operation is the same as described above.

According to this, the temperature detecting means 3 becomes unnecessary, and the cost can be reduced. It should be noted that the rise time has to take into account the variation due to the environmental temperature and the variation in components.

[0057]

As described above, according to the present invention, it is possible to reduce the rise time of the apparatus because the temperature rising operation of the heat source is not hindered by the wind from the blowing means. Effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an image forming apparatus of an orthogonal transfer system according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of the image forming apparatus of FIG. 1;

FIG. 3 is an explanatory diagram illustrating a transfer operation of the image transfer device of FIG. 1;

FIG. 4 is a schematic diagram illustrating a structure of a fixing device attached to the image forming apparatus of FIG. 1;

FIG. 5 is a block diagram showing a control system of the fixing device of FIG. 4;

FIG. 6 is a perspective view showing a peripheral structure of a fixing device in a conventional orthogonal transfer type image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing apparatus 4 Toner image carrier 10c Toner image 14 Printing paper (recording medium) 17 Heat source 18 Blowing unit 20 MPU (Control unit) 30 Heat source temperature detecting unit 31 Timer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadahiro Kugimaru 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Hiroshi Oda 1006 Kazama Kadoma Kadoma, Osaka Pref. F term (reference) 2H027 DA12 DA38 EA12 ED25 JB23 JC08 JC13 2H032 BA19 BA21 BA23 2H033 AA30 BE02 CA03 CA26 9A001 HH34 JJ35 KK42

Claims (2)

[Claims] An image forming apparatus which presses and transfers a toner image on a toner image carrier from a recording medium in a direction orthogonal to a conveying direction of the recording medium and transfers the toner image onto the recording medium; A fixing device for fixing the recording medium, a heat source performing a heating operation, blowing air to the heat source to generate hot air, and blowing means for sending the hot air toward the conveyed recording medium, Heat source temperature detecting means for detecting the temperature of the heat source, and control means for turning on the blowing means when the temperature of the heat source detected by the heat source temperature detecting means has reached a predetermined temperature, Fixing device. 2. An image forming apparatus for transferring a toner image on a toner image carrier by pressing the toner image onto the recording medium from a direction perpendicular to the direction of conveyance of the recording medium and transferring the toner image onto the recording medium. A fixing device for fixing the recording medium, a heat source performing a heating operation, blowing air to the heat source to generate hot air, and blowing means for sending the hot air toward the conveyed recording medium, A timer for measuring a heat source rising time until the temperature of the turned on heat source reaches a predetermined temperature, and control means for turning on the blowing means when the heat source rising time is counted by the timer. Fixing device.