US3806314A

US3806314A - Fixing apparatus for thermoplastic recording

Info

Publication number: US3806314A
Application number: US00233932A
Authority: US
Inventors: K Obuchi; K Takiguchi
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1971-03-11
Filing date: 1972-03-13
Publication date: 1974-04-23
Anticipated expiration: 1991-04-23
Also published as: DE2211435A1; JPS5419785B1; GB1377025A

Abstract

A vertical type fixing apparatus for thermoplastic powder recording comprising a transport means for support on which thermoplastic image patterns are deposited, a heating means for rapidly and permanently fixing the thermoplastic image patterns on the support, a blower means for circulating rising heated air, and a guide means for promoting air circulation.

Description

United States Patent Obuchi et a1.

FIXING APPARATUS FOR THERMOPLASTIC RECORDING Inventors: Kazuo Obuchi; Koichi Takiguchi,

both of Odawara, Japan Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan Filed: Mar. 13, 1972 Appl. NO.I 233,932

Foreign Application Priority Data Mar. 11, 1971 Japan 46-13342 US. Cl 432/230, 432/59, 219/216 Int. Cl G03g 8/00 8 Field of Search 263/6 E;'95/13, 14, 94;

References Cited UNITED STATES PATENTS 7/1973 Peek, Jr. eta1 432/45 1 Apr. 23, 1974 3,492,458 l/l970 White et al. 34/10 3,145,637 8/1964 Frantz 95/94 3,448,970 6/1969 Kolibas 432/62 3,700,218 10/1972 Laisney 432/62 3,498,592 3/1970 Moser et al..... 432/62 2,664,282 12/1953 Mann 432/42 Primary Examiner-John J. Camby Assistant Examiner-Henry C. Yuen Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn and Macpeak [57] ABSTRACT A vertical type fixing apparatus for thermoplastic powder recording comprising a transport means for support on which thermoplastic image patterns are deposited, a heating means for rapidly and permanently fixing the thermoplastic image patterns on the sup port, a blower means for circulating rising heated air, and a guide means for promoting air circulation.

4 Claims, 1 Drawing Figure FIXING APPARATUS FOR THERMOPLASTIC RECORDING BACKGROUND OF THE INVENTION I 1. Field of the Invention The present invention relates to an apparatus for fixing thermoplastic powder image patterns deposited on the surface of a support material. More particularly the present invention relates to a vertical type fixing apparatus in which thermoplastic powder image patterns formed loosely on the support such as, for example, a xerographic plate or an electrostatic recording or duplicating paper are fixed permanently on the support by heating.

In this disclosure, the term vertical type" fixing apparatus denotes an apparatus for fixing in which the support for the thermoplastic powder image patterns is transported vertically and one or a plurality of heating elements are provided parallel with the support to accomplish the fixing by heating.

2. Description of the Prior Art Heretofore, in the case of electrophotography or similar techniques, the so-called horizontal type fixing apparatus in which the support is transported horizontally and heating elements are provided in parallel with the carrier path to accomplish the fixing of the thermoplas tic powder image patterns formed on the carrier has been widely used. The reason the horizontal type fixing apparatus has been widely used, while the vertical type fixing apparatus has not been utilized as much, is as follows: Certain undesirable disadvantages and limitations of the vertical type fixing apparatus are known and these include a temperature reduction on the inside of the fixing apparatus and a temperature increase on the inside of the duplicating machine and similar problems due to the fact that, in the case of vertical type apparatus, relatively cold air is supplied from below and air heated by the heating elements flows upwardly. That is, the temperature reduction on the inside of the fixing apparatus requires that much more electric power be supplied to the heating elements to accomplish the fixing of the thermoplastic powder image pattern on the support, and the temperature increase in the machine may cause adverse effects on the photoconductive layer or malfunctions of and difficulties with the electrical equipment.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a novel and improved vertical type fixing apparatus for thermoplastic recording It is another object of the invention to provide a vertical type fixing apparatus which is so arranged that the electric power consumption in the apparatus is reduced to a great degree, and that the heat in the apparatus is prevented from flowing outwards resulting in an avoiding of a temperature increase in the inside of the machine suchas a duplicating machine.

To accomplish these objects, the present invention provides a blower means and guide means having the function of circulating the heated air and downwardly returning the heated air rising from the heating elements.

Other objects of the invention, as well as other advantages and features thereof, will become apparent and be better understood from a further reading of the following disclosure of an embodiment of the invention taken in conjunction with the appended drawing.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING The FIGURE depicts schematically an arrangement of the fixing apparatus in accordance with this invention.

0 DESCRIPTION OF PREFERRED EMBODIMENTS As shown in the FIGURE, the fixing apparatus is provided with a heating means 1 which consist of heating elements such as, for example, tubular infrared lamps or nichrome wires. The heating means 1 includes sufficient numbers of heating elements so as to supply the quantity of heat required to fix the thermoplastic powder image pattern on the support. Reference numeral 2 denotes a reflector for the heat radiated from said heating means 1. Reference numeral 3 denotes a circulating fan as a blower means being a main part of this invention, which rotates in the direction of the arrow to return downwardly the rising heated air. Numeral 4 indicates an internal cover for guiding the air current which is of such shape that the air circulation due to the rotation of the circulating fan 3 is promoted efficiently thereby. Numeral 5 denotes an outside cover. Reference numeral 6 denotes a exhaust fan secured to the upper part of the outside cover 5 for exhausting outwardly the remaining portion of the rising heated air which could not be recirculated downwardly by the circulating fan 3. Reference numeral 7 indicates a shutter which, during the preheating period of heating elements 1 or in an unexpected power stoppage, drops to the dotted lined position 8 so as to reduce the time required in preheating or to prevent the support from scorching or catching fire. Reference numeral 9 denotes a support for thermoplastic recording, such as, for example, a web or sheet which may be transported in a plane parallel with the direction of the heating elements disposed vertically. Numeral 10 denotes an unfixed thermoplastic powder image pattern on the support 9, while numeral 11 denotes the image pattern fixed on the support 9 after passing through the fixing apparatus.

Furthermore, in the left side of the apparatus (not illustrated), image patterns of a thermoplastic powder are deposited on the roll paper carrier using an electrophotographic process.

Reference numerals

12 and 13 denote guide rollers for guiding the vertical transport of the support 9, and both ends of the support are connected to a supply reeldevice and take-up reel device (not shown) respectively. Reference numeral 14 denotes a adiabatic plate for preventing the transmission of heat through the support paper 9 to the exposure device and/or developing device positioned in the left side of the FIGURE (not shown).

The operation of the fixing apparatus arranged in the manner described above will be now explained in greater detail hereinafter.

First, during preheating period, the shutter 7 is in the down position 8 forming a thermal seal for the heating elements 1 with the reflecting plate 2 so that the shutter 7 prevents the transmission of the heat to the support 9 and the heating elements 1 themselves are heated efficiently thus reducing the time for preheating. Just after the heating elements 1 are heated sufficiently to permit fixing, the shutter moves up to the position 7 and, at the same time, transport of the support 9 is begun. Thus the cycle of operation of the fixing for thermoplastic recording or duplicating starts. The air heated by the heating elements 1 rises along the support 9 and is taken in by the circulating fan 3 rotating in the direction of the arrow, essentially without leakage. The absorbed hot air is guided passed through the back side of the reflecting plate 2 inside of the internal cover 4 to an opening formed between the lower end of the reflecting plate 2 and that of the internal cover 4, and the air is blown therefrom onto the support 9 at an angle perpendicular to the support. The temperature of the circulating air may be increased by coming into contactwith the reflecting plate 2 while passing through the inside of the internal cover 4. Thus, it will be apparent that the heated hot air is blown directly onto the carrier on which thermoplastic powder image patterns are deposited with a high fixing efficiency and accordingly the electric power to be applied to the heating elements may be reduced. The blown air current is heated by the heating elements and rises to be absorbed by the circulating fan again thus, the air circulating process maybe repeated during the operation in which thermoplastic recording or duplieating is performed.

THe circulation of the heated air current prevents the inflow of relatively cold air from the outside into the apparatus resulting in avoiding a reduction of temperature in the fixing apparatus with little leakage of heat. Even a small quantity of air which might leak into the recording or duplicating apparatus would be exhausted out immediately without any temperature increase in the recording or duplicating apparatus.

After the recording or duplicating operation is finished the power supplied to the heating elements is switched off, and at the same time the shutter drops down to the position 8 and transport of the support is stopped.

The fixing apparatus of the present invention as described above has been operated and compared with that of prior art. The results obtained are as follows:

Experiments have been made for the following three,

cases: (i) a fixing operation of the vertical type fixing apparatus with the circulating fan being rotated, (ii) fixing operation of the vertical type fixing apparatus without the circulating fan being rotated, (iii) a fixing operation of the horizontal type fixing apparatus with heating elements disposed horizontally. The power consumption required to accomplish the rapid fixing of the image patterns of thermoplastic powder on the support was measured in the three respective cases under the following conditions: 2KW of electric power was applied for preheating for l minute. The speed of the support transport was 10.2 cm/sec. The width of the support paper was 30 cm, and a 1.5 cm gap was set between the surface of the support paper and the heating elements. A thermoplastic powder of the type commercially available as 914/420 TONER from Fuji Xerox Company was used.

The measured power consumption which fixed the thermoplastic powder image pattern perfectly on the support was (i) 1.0 KW in the vertical type apparatus with rotating the circulating fan, (ii) 1.35 KW in the vertical type apparatus without rotating the circulating fan, and (iii) 1.2 KW in the horizontal type apparatus.

The circulating fan used in .the experiment of the vertical type apparatus had a diameter of 10cm. and a rotating speed of 800 rpm. and the heated air current jetted from the opening 15 in the FIGURE at a temperature of 200C and a flow rate of 2m/sec.

From the above described results of the experiments,

to a considerably high temperature (for example,

200C in the embodiment described above), they should be heat-resistant to such high temperatures.

While the present invention has been described with reference to a specific embodiment, it is to be understood that the embodiment described is only for the purposes of illustration and various modifications and changes may be made in the present invention without departing from the spirit and the scope of the invention as defined herein and by the appended claims.

What is claimed is:

1..A heat-fixing apparatus for thermoplastic powder recording or duplicating comprising a 1. transport means for vertically transporting a support carrying image patterns of a thermoplastic powder,

2. one or a plurality of heating elements disposed in parallel with the transport path of said support,

3. blower means for collecting heated air as it rises from areas adjacent said heating elements and downwardly returning said heated air onto the surface of said support in an area of said support below said heating elements,

4. guide means for promoting the circulation of the air, 5. a reflecting plate at the side of said heating elements opposite to said support transport path, and

6. a shutter movably mounted between said support and said heating elements, whereby heat supplied to said support from said heating elements can be discontinued when the fixing operation is not practiced.

2. A heat-fixing apparatus for thermoplastic powder recording or duplicating as set forth in claim 1 wherein said transport means transports said support downwardly, whereby an ascending current of heated air from said heating elements warms said support prior to said blower means comprises a circulating fan.

Claims

1. A heat-fixing apparatus for thermoplastic powder recording or duplicating comprising a 1. transport means for vertically transporting a support carrying image patterns of a thermoplastic powder, 2. one or a plurality of heating elements disposed in parallel with the transport path of said support, 3. blower means for collecting heated air as it rises from areas adjacent said heating elements and downwardly returning said heated air onto the surface of said support in an area of said support below said heating elements, 4. guide means for promoting the circulation of the air, 5. a reflecting plate at the side of said heating elements opposite to said support transport path, and 6. a shutter movably mounted between said support and said heating elements, whereby heat supplied to said support from said heating elements can be discontinued when the fixing operation is not practiced.

2. A heat-fixing apparatus for thermoplastic powder recording or duplicating as set forth in claim 1 wherein said transport means transports said support downwardly, whereby an ascending current of heated air from said heating elements warms said support prior to fusing of the thermoplastic powder.

3. A heat-fixing apparatus for thermoplastic powder recording or duplicating as set forth in claim 1 further comprising exhaust means located upwardly of said blower means for exhausting from the apparatus that portion of heated air which is not recirculated downwardly by said blower means.

4. A heat-fixing apparatus for thermoplastic powder recording or duplicating as set forth in claim 1 wherein said blower means comprises a circulating fan.

4. guide means for promoting the circulation of the air,

5. a reflecting plate at the side of said heating elements opposite to said support transport path, and