JPH0528657U - Recording sheet cooling device - Google Patents

Abstract

(57) [Summary] [Object] To provide a recording sheet cooling device in which a recording sheet is efficiently cooled, is small in size and low in cost as a whole, and does not require a large space for its installation. A Peltier element that cools a cooling guide plate that cools and conveys a recording sheet in cooperation with a conveying roller or a conveying belt, and the recording sheet is cooled while being conveyed by a cooling guide plate of a conveying unit. This cooling guide plate is cooled by the Peltier element.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a recording sheet cooling device of an image recording machine having a heat fixing device such as a printer and a facsimile.

[0002]

[Prior Art]

 An image recording machine having a conventional heat fixing device and a recording sheet cooling device will be described with reference to FIG. 1 showing an embodiment of the present invention. Reference numeral 1 is a heat fixing device and 20 is a recording sheet cooling device. ..

On the thermal fixing device 1, a recording sheet 5 is loaded with an image of unfixed toner transferred by a transfer section (not shown), and is carried into a nip between the fixing roller 2 and the pressure roller 3 to apply a pressure. By means of pressing the pressure roller 3 against the fixing roller 2 by means, the unfixed toner image is fixed on the recording sheet 5 by being heated and pressed. The fixing roller 2 has a built-in heater 4 and its temperature is usually controlled to 185 ° C. by a thermistor 8. The pressure roller 3 has a 5 mm rubber layer on its surface.

By the way, the recording sheet 5 fixed in this way is hot and easily curls, and when it is discharged to the paper discharge tray and stacked as it is, when it is continuously fed, heat is accumulated between the recording sheets 5. In some cases, the toner fixed on the recording sheet 5 adheres to the back side of the next recording sheet 5 with adhesiveness, so-called blocking phenomenon may occur. This is a phenomenon often observed especially when the recording sheets 5 after fixing, such as in a high-speed machine, are stacked before being sufficiently cooled. Then, the recording sheets 5 stuck together like this cause a problem that they must be peeled off one by one when they are taken out from the paper discharge tray.

In order to solve such a problem, the recording sheet 5 which has been fixed is separated by the separation claw 11 and conveyed to the paper discharge rollers 13 and 14 via the guide plate 12 at this time. No. 5 is around 120 ° C., after which it is cooled and conveyed by the recording sheet cooling device 20.

[0006]

[Problems to be solved by the device]

 By the way, in such a conventional recording sheet cooling device, there is one in which a fin is provided at an end portion to cool the recording sheet and a heat pipe is used to cool the fin, but this is not effective in cooling. Unfortunately, in order to increase this cooling efficiency, it is necessary to increase the number of fins or increase its area, and since this heat pipe has a cylindrical shape, the contact area is small and this cooling efficiency is also high. However, in order to increase this cooling efficiency, the heat pipe must have a large diameter, which makes the entire cooling device large and costly, and requires a large space for its installation. There is a problem.

Therefore, an object of the present invention is to solve the problems of the conventional recording sheet cooling device as described above, to make the recording sheet compact and low in cost, and not to require a large space for its installation. To provide a cooling device.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a recording sheet cooling device having a conveying means for cooling and conveying a recording sheet on which an image is fixed by a heat fixing device, wherein the conveying means is a cooling means for conveying the recording sheet. It is characterized by comprising a guide plate and a Peltier element for cooling the cooling guide plate, and its conveying means is a conveying roller or a conveying roller for conveying the recording sheet in cooperation with the cooling guide plate. It has a belt.

[0009]

[Action]

 In this invention as described above, the recording sheet fixed by the heat fixing device is discharged to the recording sheet cooling device in the same manner as in the conventional device, and is conveyed by the cooling guide plate of the conveying means of the cooling device. After cooling, the cooling guide plate is cooled by the Peltier element, and thus the recording sheet is efficiently cooled. At that time, the transport roller or the transport belt cooperates with the cooling guide plate to transport the recording sheet.

[0010]

【Example】

 In the embodiment of the present invention shown in the drawings, the first embodiment shown in FIGS. 1 and 2 and the other embodiments are common in many parts, and thus such parts are the same as the first embodiment. The reference numerals will be quoted and the description thereof will be omitted, and mainly different parts will be explained. The recording sheet cooling device 20 according to the first embodiment is provided with a relay guide plate 21 and a cooling guide plate 23 at positions facing the paper discharge rollers 13 and 14, respectively, and above the cooling guide plate 23. A conveyance roller 22 that contacts and rotates is provided. The cooling guide plate 23 in this embodiment is made of a material having a high thermal conductivity such as aluminum or copper, and may be provided with a release layer such as Teflon on the front and back sides thereof in order to improve transportability, if necessary. Good.

A Peltier element 28 is mounted on the back surface of the cooling guide plate 23, and a radiation fin 30 is attached to the Peltier element 28. The radiation fin 30 is cooled by a radiation fan 31. The Peltier element is a plate-shaped semiconductor, and one side of the Peltier element heats up and the other side cools down by passing a direct current, and the temperature can be adjusted by the amount of the flowing current.

The recording sheet 5 on which the unfixed toner has been fixed by the thermal fixing device 1 is conveyed to the recording sheet cooling device 20 in the same manner as in the above-described conventional device. Then, the conveyed recording sheet 5 is cooled while being conveyed by the cooling guide plate 23 and the conveying roller 22, and at that time, the cooling guide plate 23 is cooled by the heat radiation fan 31. , The recording sheet 5 is cooled by the Peltier element 28, and the recording sheet 5 comes into contact therewith and is cooled. Since the contact time is long, the recording sheet 5 is efficiently cooled. The paper is ejected to the paper ejection tray 50 via the paper ejection roller 24 and the paper ejection rollers 25 and 26.

The second embodiment shown in FIG. 3 is the same as the first embodiment except that the relay guide plate 21, the conveyance roller 22, and the discharge guide plate 24 are arranged below the cooling guide plate 23. There is nothing different.

The third and fourth embodiments shown in FIGS. 4 and 5 employ a carrying belt 39 instead of the carrying roller 22 of the first and second embodiments. There is no difference between and except that the positions of the cooling guide plate 23 and the conveyor belt 39 are upside down. In these embodiments, reference numerals 40 and 41 denote rollers around which the conveyor belt 39 is stretched. In these third and fourth embodiments, the recording sheet 5 is in better contact with the cooling guide plate 23 and the cooling efficiency is higher than in the first and second embodiments.

[0015]

[Effect of the device]

 This invention is as described above, and comprises a cooling guide plate for transporting the recording sheet by the transporting means for cooling and transporting the fixed recording sheet, and a Peltier element for cooling the cooling guide plate. The recording sheet discharged from the heat fixing device is cooled while being conveyed by the cooling guide plate of the conveying means, and this cooling guide plate is cooled by the Peltier element, so that the recording sheet is efficiently cooled and the overall size is small. It has the advantages of low cost and does not require a large space for its installation. Further, the conveying means is configured such that the cooling guide plate and the conveying roller or the conveying belt cooperate to convey the recording sheet, so that the recording sheet is smoothly conveyed. Especially, in the case of the conveying belt, the recording sheet is cooled. Good contact with the guide plate improves cooling efficiency.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a main part of a first embodiment of the present invention.

FIG. 2 is a partially enlarged front view of the above.

FIG. 3 is a vertical sectional front view of a main part of a second embodiment of the present invention.

FIG. 4 is a vertical sectional front view of a main part of a third embodiment of the present invention.

FIG. 5 is a vertical cross-sectional front view of essential parts of a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Fixing device 20 Cooling device 22 Conveying roller 23 Cooling guide plate 28 Peltier element 39 Conveying belt

Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location G03G 15/20 102 6830-2H 21/00 6605-2H (72) Inventor Jun Okamoto Nakamagome 1 Ota-ku, Tokyo 3-6, Ricoh Co., Ltd. (72) Inventor Kenichi Hasegawa 1-3-6, Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. A recording sheet cooling apparatus having a conveying means for cooling and conveying a recording sheet on which an image is fixed by a heat fixing device, wherein the conveying means includes a cooling guide plate for conveying the recording sheet, and the cooling guide plate. A recording sheet cooling device comprising a Peltier element for cooling. 2. The recording sheet cooling device according to claim 1, wherein the conveying means has a conveying roller which cooperates with the cooling guide plate to convey the recording sheet. 3. The recording sheet cooling device according to claim 1, wherein the conveying unit has a conveying belt that cooperates with the cooling guide plate to convey the recording sheet.