JP2002333814A - Ejection paper cooler of imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ejection paper cooler of an imaging device, in which temperature rise within the device is suppressed by sufficiently cooling a sheet of paper after a fixation, even though a large size paper and an OHP film or the like are used. SOLUTION: In the imaging device, an ejection roller (a paper-ejection section) 10c is arranged immediately behind a fixing device (a fixing means) 10. A cooling fan is provided in the vicinity of a suction port formed on a body. A ventilation duct 11 is provided to guide external air sucked by the fan to the roller 10c. A discharge port 11c of the duct 11 is made opened immediately behind the paper exit of the device 10. By constituting it this way, since air from the port 11c of the duct 11 is blown onto a recording medium (sheet of paper) S, immediately after a fixation to efficiency cool the medium S, rise of the temperature in the device is suppressed by sufficiently cooling the medium S after the fixation, even though the medium is a large size paper or an OHP film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge cooling device provided on a fixing means discharge side of an image forming apparatus such as a copying machine, a printer, and a facsimile using an electrophotographic system.

[0002]

2. Description of the Related Art As a conventional sheet discharging cooling device, Japanese Patent Laid-Open No.
There is one disclosed in Japanese Patent Application Laid-Open No. 1-030891, the configuration of which is shown in FIG.

FIG. 4 is a cross-sectional view showing a conventional sheet discharge cooling device. As shown in FIG.
4 and an exhaust port 105 are provided. The cooling fan 101 provided inside the suction port 104
The paper discharge cooling device is configured by connecting the ventilation duct 110 between the two.

[0004] By driving the cooling fan 101, air outside the machine is sucked in from the air inlet 104, and is blown to the paper discharge unit 102 through the ventilation duct 110 to discharge air from the air outlet 105 to the outside of the machine. By discharging the paper, the paper discharge unit 102 can be cooled. That is, the air blown to the paper discharge unit 102 takes heat from the recording medium 102 a in the paper discharge unit 102, and the recording medium 102 a whose temperature has decreased is discharged to the discharge tray 106.

[0005]

However, in the above-described conventional sheet discharging and cooling apparatus, the recording medium after fixing cannot be sufficiently cooled, and the recording medium having a high temperature after fixing in the double-sided conveyance path during double-sided printing. There is a problem that the inside temperature rises due to the passage of air. Particularly, in an apparatus that forms an image up to a large-sized recording medium such as an A3 size, the temperature inside the apparatus further increases because the recording medium cannot be sufficiently cooled when printing a large-sized recording medium on both sides. There was a problem.

In the case where the recording medium is an OHP film or the like, even if the recording medium is of a normal size such as A4 size, the cooling is insufficient, so that the recording medium is placed on the OHP film or the like discharged to a discharge tray. The next OHP film or the like is discharged before the molten toner is solidified, and there is also a problem that the OHP films and the like stick to each other in the molten toner portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object thereof is to sufficiently cool a sheet after fixing even if the sheet is a large-size sheet or an OHP film to raise the temperature inside the apparatus. It is an object of the present invention to provide a sheet discharge cooling device for an image forming apparatus, which can suppress the occurrence of printing.

[0008]

According to a first aspect of the present invention, there is provided an image forming apparatus having a paper discharge unit disposed immediately after a fixing unit. A cooling fan is provided in the vicinity, and a ventilation duct for guiding outside air sucked by the cooling fan to the paper discharge unit is provided,
An exhaust port of the ventilation duct is opened immediately after the paper exit of the fixing unit.

According to a second aspect of the present invention, in the first aspect of the present invention, the suction port is formed on a side surface of the fixing unit.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the ventilation duct is disposed so as to pass right above the fixing means.

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, the exhaust port of the ventilation duct is opened immediately above the sheet path immediately after the sheet exit of the fixing means, and the sheet is conveyed. The air blows in a direction perpendicular to the direction.

According to a fifth aspect of the present invention, in the first, second or third aspect of the present invention, an exhaust port of the ventilation duct is opened to a side of a sheet path immediately after a sheet exit of the fixing means, and the sheet is conveyed. The air blows in a direction perpendicular to the direction.

Therefore, according to the present invention, since the exhaust port of the ventilation duct for guiding the outside air sucked by the cooling fan to the sheet discharge section is opened immediately after the sheet exit of the fixing means, the air from the exhaust port is fixed. It is possible to efficiently cool the sheet by spraying it on the immediately succeeding sheet. Even if the sheet is a large-size sheet or an OHP film, it is possible to sufficiently cool the sheet after fixing and suppress an increase in the temperature inside the apparatus. .

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a tandem-type color LBP (color laser printer) equipped with a sheet discharge cooling device according to the present invention.
FIG.

In FIG. 1, reference numeral 1 (1a to 1d) denotes a drum-type electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum) as a latent image carrier which rotates at a predetermined process speed in a direction indicated by an arrow (counterclockwise). ), And the photosensitive drums 1a, 1
b, 1c, and 1d respectively share a yellow (Y) component, a magenta (M) component, a cyan (C) component, and a black (Bk) component of a color image. These photosensitive drums 1a to 1d are rotationally driven by a drum motor (DC servo motor) (not shown), but an independent drive source may be provided for each of the photosensitive drums 1a to 1d. The rotation of the drum motor is controlled by a DSP (Digital Signal Processor) (not shown), and the other controls are performed by a CPU (not shown).

The electrostatic attraction / conveying belt 9a includes a driving roller 9b, fixed rollers 9c and 9e, and a tension roller 9b.
The recording medium S is stretched and driven by a driving roller 9b to rotate in a direction indicated by an arrow in FIG.

A description will now be given of yellow (Y) among the four colors as an example.

The photosensitive drum 1a is uniformly charged to a predetermined polarity and potential by the primary charging means 2a during its rotation. Then, the photosensitive drum 1a is exposed to a light image by laser beam exposure means (hereinafter, referred to as a scanner) 3a, and an electrostatic latent image of image information is formed on the photosensitive drum 1a.

Next, a toner image is formed on the photosensitive drum 1a by the developing unit 4a, and the electrostatic latent image is visualized. Similar steps are performed for the other three colors (magenta (B), cyan (C), and black (Bk)).

The four color toner images are recorded on the recording medium S conveyed by the paper feed roller 8b at a predetermined timing.
Are stopped and re-conveyed, the toner images are sequentially transferred to the recording medium S at the nip between the photosensitive drums 1a to 1d and the electrostatic attraction conveyance belt 9a. At the same time, the photosensitive drums 1a to 1d after the transfer of the toner image to the recording medium S are cleaned by the cleaning units 6a and 6d.
Residual deposits such as transfer residual toner are removed by b, 6c and 6d, and are repeatedly provided for image formation.

The recording medium S on which the toner images have been transferred from the four photosensitive drums 1a to 1d is separated from the surface of the electrostatic attraction / conveying belt 9a at the drive roller 9b and sent to the fixing device 10 where the toner image is transferred. After the image is fixed, the image is discharged to a discharge tray 13 by a discharge roller 10c.

The above is the operation of the apparatus in one-sided printing.

At the time of double-sided printing, the discharge roller 10c is moved until the rear end of the recording medium S passes through the discharge double-sided guide 10d.
The recording medium S is transported by the
By reversing c, the recording medium S is guided to the double-sided conveyance path.

More specifically, by the reverse rotation of the discharge roller 10c, the rear end of the recording medium S is conveyed along the upper surface of the discharge double-sided guide 10d, and the recording medium S is further guided by guide ribs 11a provided below the ventilation duct 11. The sheet is conveyed along a guide rib 12 a provided at a lower portion of the operation panel 12, and is sent to the double-sided roller 14. Further, the recording medium S passes through the downstream double-sided rollers 15 and 16,
7, the photosensitive drums 1a to 1d and the electrostatic attraction transport belt 9a
Again sent to the nip. Subsequent operations are exactly the same as in the case of single-sided printing.

Next, details of the sheet discharge cooling device according to the present invention will be described with reference to FIGS. FIG. 2 is an enlarged sectional view showing the vicinity of the sheet discharge cooling device, and FIG. 3 is a front view showing the vicinity of the sheet discharge cooling device.

As shown in FIG. 3, a cooling fan 18 is provided at the right end of the ventilation duct 11 provided so as to cover the fixing device 10 (passing right above the fixing device 10). Then, the cooling fan 18 is driven to suck air from a suction port (not shown) formed in the cover 19 indicated by a two-dot chain line to send air in the direction of arrow B. As a result, air flows in the direction of arrow C in FIG. 2, and the air is discharged from the exhaust port 11 c of the ventilation duct 11. Although not shown,
The suction port is formed on the side surface of the fixing device 10 of the cover 19.

Here, the cooling fan 18 is connected to the ventilation duct 11.
And the ventilation duct 11 is covered by a cover 19.
It is fixed to. This allows the ventilation duct 11 to be opened together with the cover 19 when the cover 19 is opened from the main body when the jam is cleared when a jam occurs inside the fixing device 10 or when the fixing device 10 is replaced due to its life. 11 does not hinder the jam processing or the replacement operation of the fixing device 10.

Further, since the exhaust port 11c of the ventilation duct 11 has a width substantially equal to the width in the short direction of A4 size (the width described as "blowing width" in FIG. 3), the recording medium S
Is blown at this width.

The recording medium S on which the toner image has been transferred
Is cooled by the air blown from the exhaust port 11c of the ventilation duct 11 in a direction perpendicular to the conveying direction of the recording medium S immediately after the toner image is fixed by the fixing device 10 and discharged by the discharge roller 10c. . Therefore,
Even when a large-sized recording medium S such as A3 size is printed on both sides, the recording medium S is sufficiently cooled before entering the two-sided conveyance path downstream of the discharge roller 10c, so that an increase in the machine temperature is suppressed. .

In the present embodiment, the operation panel 12 whose temperature rise causes a failure is disposed immediately above the two-sided conveyance path. The temperature rise of 12 is also kept low.

Further, even when the recording medium S is an OHP film or the like, the toner image is fixed on the recording medium S by the fixing device 10, and immediately after the recording medium S is discharged by the discharge roller 10c, the toner image is discharged from the exhaust port 11c. Of the recording medium (OHP) on the discharge tray 13
Film, etc.) and the toner on the next recording medium (O
(HP film etc.) S is always solidified before being discharged, and sticking between the recording media S is prevented.

In this embodiment, the exhaust port 11c of the ventilation duct 11 is opened immediately above the recording medium passage immediately after the exit of the fixing device 10, and the air is blown in a direction perpendicular to the conveying direction of the recording medium S. However, the exhaust port 11c of the ventilation duct 11 is opened to the side of the recording medium passage immediately after the exit of the fixing device 10, and the air is blown in a direction perpendicular to the conveying direction of the recording medium S. Even in this case, the same effect as described above can be obtained.

[0034]

As is apparent from the above description, according to the present invention, in the image forming apparatus having the paper discharge section disposed immediately after the fixing means, the cooling fan is provided near the suction port formed in the main body. A ventilation duct for guiding the outside air sucked by the cooling fan to the paper discharge section, and an exhaust port of the ventilation duct is opened immediately after the paper exit of the fixing means, so that a large-size or OHP film or the like is provided. Even after the fixing of the sheet, it is possible to obtain an effect that the sheet after fixing can be sufficiently cooled to suppress an increase in the internal temperature of the apparatus.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a tandem-type color LBP (color laser printer) including a sheet discharge cooling device according to the present invention.

FIG. 2 is an enlarged sectional view of the vicinity of a discharge cooling device of a tandem type color LBP (color laser printer) including the discharge cooling device according to the present invention.

FIG. 3 is a front view of a tandem type color LBP (color laser printer) provided with a sheet discharge cooling device according to the present invention in the vicinity of the sheet discharge cooling device.

FIG. 4 is a partial sectional view showing a conventional sheet discharge cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fixing device (fixing means) 10c Discharge roller (discharge part) 11 Ventilation duct 11c Exhaust port 13 Discharge tray (discharge part) 18 Cooling fan S Recording medium (paper)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 JA11 JB15 JB16 JC08 JC11 JC13 JC14 JC20 ZA07 2H033 AA09 BA06 BA10 BA12 BA29 BB01 2H071 AA26 AA35 AA38 AA48 BA03 BA14 BA27 DA12 DA24 EA04 EA18 3F101 FA

Claims (5)

[Claims] 1. An image forming apparatus comprising a paper discharge unit disposed immediately after a fixing unit, wherein a cooling fan is provided in the vicinity of a suction port formed in a main body, and external air sucked by the cooling fan is discharged to the paper discharge unit. And a ventilation duct for leading the air to the fixing device, and an exhaust port of the ventilation duct is opened immediately after the paper exit of the fixing unit. 2. The sheet discharge cooling device for an image forming apparatus according to claim 1, wherein said suction port is formed on a side surface of said fixing unit. 3. The sheet discharge cooling device for an image forming apparatus according to claim 1, wherein the ventilation duct is arranged to pass immediately above the fixing unit. 4. The apparatus according to claim 1, wherein an exhaust port of the ventilation duct is opened immediately above the paper path immediately after the paper exit of the fixing unit, and air is blown in a direction orthogonal to a paper transport direction. Claim 1, 2, or 3
A sheet discharge cooling device for an image forming apparatus according to any one of the preceding claims. 5. An air outlet of the ventilation duct is opened to a side of a paper path immediately after a paper outlet of the fixing means,
4. The sheet discharge cooling device for an image forming apparatus according to claim 1, wherein air is blown in a direction perpendicular to a sheet conveying direction.