JPH0212166A - Structure for recording paper guide path - Google Patents

Abstract

PURPOSE:To prevent the dewing of a water drop caused by the quick cooling of recording paper by constituting the guide supporting face of a recording paper guide path of plural discontinuous supporting faces which are separated from one another and arranging discontinuous supporting faces so that the faces always kept in contact with the optional spot of the recording paper during the movement of the recording paper can be avoided. CONSTITUTION:Since the guide supporting face forming the recording paper guide path 66 is constituted of the plural discontinuous supporting faces which are separated from one another, the contact area of the recording paper with the guide supporting face of the recording paper guide path 66 is made small. Since the plural discontinuous supporting faces are arranged so that the faces always kept in contact with the optional spot of the recording paper while the recording paper is moving can be avoided, and therefore only specified spots of the recording paper always being kept in contact with the guide supporting face of the recording paper guide path 66 can be evaded. Therefore, the recording paper can be prevented from wholly and locally being cooled. Thus, the dewing of the water drop on the recording paper can be eliminated.

Description

[Detailed Description of the Invention] [Summary] Regarding the structure of the recording paper guide path provided on the recording paper ejection side of the heat fixing mechanism, the overall The purpose of this invention is to apply a structure of the recording paper guide path that can solve not only the rapid cooling problem but also the local rapid cooling problem. The forming guide support surface is composed of a plurality of discontinuous support surfaces separated from each other, and these discontinuous support surfaces are arranged so as to avoid constant contact with any part of the recording paper during movement of the recording paper. The structure of the recording paper guide path is characterized in that:

[Industrial Field of Application] The present invention relates to the structure of a recording paper guide path provided on the recording paper ejection side of a thermal fixing mechanism of a toner recording device that uses toner as a recording medium, such as an electrophotographic recording device or an electrostatic recording device. .

The recording process of an electrophotographic recording device, which is a type of toner recording device that uses toner, includes a charging stage in which an electric charge is charged on a photosensitive drum made of a photoconductive substance, and a step in which document information is optically transferred to the charged area. an exposure stage in which an electrostatic latent image is formed by projecting the image onto the recording paper; a development stage in which the electrostatic latent image is developed with toner; a transfer stage in which the developed toner is transferred to recording paper; and the transferred toner is transferred to the recording paper. and a fixing step of heat fixing. In recent years, instead of optically projecting document information onto a photosensitive drum to form an electrostatic latent image on the photosensitive drum, semiconductor lasers, light emitting diodes, etc. have been used on photosensitive drums made of dielectric materials, etc. Toner recording devices have also been developed that form electrostatic latent images by directly writing character data using optical writing means, and such recording devices are used as printers for word processors, microcomputers, etc. Or, it is incorporated into facsimiles, etc.

The toner recording device as described above is provided with a heat fixing mechanism consisting of a heat roller and a backup roller, and these rollers are arranged close to each other in parallel. The recording paper that has undergone the transfer stage is passed between the heat roller and the backup roller in such a manner that its transfer surface is brought into pressure contact with the heat roller. At this time, the transfer surface of the recording paper is pressurized by a heat roller and heat is applied to the transfer surface, which melts the fine particle resin contained in the toner on the transfer surface of the recording paper. The toner will be fixed on the recording paper. On the other hand, a recording paper guide path is provided on the recording paper ejection side of the heat fixing mechanism, and the recording paper discharged from the heat fixing mechanism is supported on and moved along the recording paper guide path.

The present invention is directed to improving the structure of such a recording paper guide path.

[Conventional technology]

Now, referring to FIG. 9, the configuration of a typical conventional recording paper guide path is schematically shown together with a heat fixing mechanism. In FIG. 9, reference numeral 10 indicates a heat fixing mechanism, and this heat fixing mechanism 10 is composed of a heat roller 12 and a backup roller 14. The recording paper P that has undergone the transfer stage is made to enter between the heat roller 12 and the backup roller 14 from the right side in FIG. undergo heat fixing treatment. A pair of guide path forming members 16 and 18 are provided on the recording paper ejection side of the thermal fixing mechanism 10 and are spaced apart from each other. It extends along the axial direction of both rollers in such a manner that the rollers are interposed therebetween.

In short, the recording paper guide path 20 is formed by the inner facing wall surfaces of the pair of guide path forming members 16 and 18 so as to face the nip between the rollers 12 and 14, and thereby the recording paper is discharged from the heat fixing mechanism 10. P is guided to a recording paper guide path 20.

The pair of guideway forming members 16 and 20 are made of a suitable metal material, and each guideway forming member has a plate-like shape. That is, the pair of guide path forming members 16 and 18
The inner facing wall surface is a flat guide support surface, and the recording paper guide path 20 is formed by these flat guide support surfaces. Therefore, when the recording paper P is ejected from the heat fixing mechanism 10 and guided into the recording paper guide path 20, the recording paper P
can come into contact with the entire flat guide support surfaces of the pair of guide path forming members 16 and 18 (particularly with respect to the guide path forming member 16 located on the lower side).

By the way, the temperature of the recording paper P discharged from the heat fixing mechanism 10 is quite high due to the heat fixing process, and the recording paper P at such a high temperature covers the entire flat guide support surface of the guide path forming member. When they come into contact with each other, the heat of the recording paper P is rapidly absorbed by the guide path forming member, and the recording paper P reaches 2. As a result, water droplets form on the recording paper P (FIG. 9). Needless to say, such condensation of water droplets degrades the quality of the recording paper P and must be avoided.

Therefore, in order to prevent such rapid cooling of the recording paper, a structure of the recording paper guide path has been proposed that is configured to minimize the contact area of the recording paper with the guide support surface of the guide path forming member. The structure of such a recording paper guide path is schematically shown in FIG. 1O. In FIG. 10, the same reference numbers as in FIG. 9 are used for the thermal transfer mechanism, heat roller, and backup roller. The same reference symbols are also used for recording paper.

In the conventional example shown in FIG. 10, a pair of guide path forming members 22 and 24 are provided on the recording paper ejection side of the heat fixing mechanism 10 in the same manner as in the case of FIG. A recording paper guide path 26 is formed between the inner facing wall surfaces of the guide path forming members 22 and 24 . However, unlike the case in FIG. 9, the pair of guide path forming members 2
A plurality of rib elements 26 and 28 are formed on each of the inner facing wall surfaces 2 and 24 along the traveling direction of the recording paper P, and the top surfaces of these rib elements 26 and 28 serve as supporting surfaces for the recording paper P. . That is, as shown in FIG. 11, the recording paper P moves along the recording paper guide path 26 while being supported by the top surface of the rib element 26. In this way, in the conventional example shown in FIG. 10, the contact area of the recording paper P with the guide support surface of the guide path forming member is smaller than in the conventional example shown in FIG. is not rapidly taken away by the guide path forming member, and the recording paper P is not rapidly cooled as in the case of FIG.

(Problem to be Solved by Ill) However, in the conventional example shown in FIG. 1O, the problem of water droplets condensing on the recording paper P is not completely solved.

This is because, as is clear from FIG.
and 28 extend along the traveling direction of the recording paper P, so that when the recording paper P is moved along the top surface of the rib element, only a specific part of the recording paper P always remains on the rib element. This is because they are placed in contact with the top surface, so that only those specific locations are quenched and water droplets can condense there. In short, in the conventional example shown in FIG. The problem of water droplet condensation due to localized rapid cooling of the paper P has not been solved.

Therefore, an object of the present invention is to provide a structure of a recording paper guide path provided on the recording paper ejection side of a heat fixing mechanism of a toner recording apparatus, and to provide a structure for preventing the recording paper from coming into contact with the guide support surface of the recording paper guide path. The purpose is to apply a structure of the recording paper guide path that can solve the local quenching problem as well as the overall quenching problem.

[Means to solve the problem]

In the configuration of the recording paper guide path according to the present invention, the guide support surface of the recording paper guide path is composed of a plurality of discontinuous support surfaces separated from each other, and these discontinuous support surfaces support the recording paper while the recording paper is moving. Arranged to avoid constant contact with any point.

[For production]

According to the present invention, since the guide support surface forming the recording paper guide path is composed of a plurality of discontinuous support surfaces separated from each other, the contact area of the recording paper with the guide support surface of the recording paper guide path is reduced, and Since the discontinuous support surface of the recording paper is arranged to avoid constant contact with any part of the recording paper during movement of the recording paper, the identification of the recording paper with respect to the guide support surface of the recording paper guide path is avoided. It is also avoided that only those parts are in constant contact with each other.

〔Example〕

Next, embodiments of the structure of the recording paper guide path according to the present invention will be described in detail with reference to FIGS. 1 to 8 of the accompanying drawings.

First, referring to FIG. 1, the toner recording device is connected to an external printer 30 such as a word processor or a microcomputer.
(Only a part of which is shown in FIG. 1) shows an example in which the structure of the recording paper guide path according to the present invention is implemented. In FIG. 1, a part of the external printer 30, ie, the recording paper ejection section 32, is in an open state. That is, the recording paper ejection section 32 includes an opening/closing frame 36 pivotally mounted to the main frame 34 of the external printer 30, and by rotating the opening/closing frame 36 with respect to the main frame 34, the recording paper ejection section 32 can be opened. 3
2 takes an open position as shown in FIG. 1, and when the recording paper ejecting section 32 is rotated downward toward the main frame 34 from this open position, the recording paper ejecting section 32 takes a closed position. .

Referring to FIG. 2, the inside of the recording paper ejection section 32 shown in FIG. 1 is shown enlarged and cut open from the side.
An access cover 38 is provided so that the inside of the recording paper ejection section 32 can be accessed from the outside. The access opening/closing cover 38 is attached to the opening/closing frame 3 with a pivot 40.
The access cover 38 is shown in FIGS. 1 and 2 locked in its closed position by a locking lever 42 (FIG. 2). FIG. 3 is a view corresponding to FIG. 2, and in FIG. 3, the access cover 34 is shown in its open position by releasing the lock lever 42.

To explain in detail how to open and close the access cover 38, a lock lever 42 is pivotally attached to the open/close frame 38 by a pivot 44 (FIGS. 2 and 3) at one end of the access cover 38. This is usually carried out in the locked position (for example by a torsion spring (not shown)
1 and 2). On the other hand, the other end side of the access opening/closing cover 38 and the opening/closing frame 38
A tension coil spring 46 (FIG. 1) is provided between the access opening and closing cover 38, and the access opening/closing cover 38 is normally elastically biased toward the closed position shown in FIG. Become. When the access cover 38 is in the closed position, the tension coil spring 46 is located above the pivot 40 (in FIG. 2), so that the access cover 38 is elastically biased toward the closed position. However, when the access opening/closing cover 38 is rotated to the open position shown in FIG. 3, the tension coil spring 46 is moved to the lower side of the pivot 40 (in FIG. 3), and at this time The open/close cover 38 is elastically biased toward the open position (FIG. 3).

As shown in FIGS. 2 and 3, a thermal fixing mechanism 48 is provided within the recording paper discharge section 32, and this thermal fixing mechanism 48 is composed of a heat roller 50 and a backup roller 52. Between the heat roller 50 and the backup roller 52 is a recording paper (not shown) that has undergone a toner transfer stage.
is passed from the direction of arrow a, for example, in such a manner that its transfer surface is brought into pressure contact with the heat roller 50, and at this time, the transferred toner is thermally fixed on the recording paper in the manner described above. The heat roller 50 has a structure in which a roller element 54 made of a non-conductive insulating material is coated with an electrical resistance layer 56, and the heat roller 50 is heated by energizing the electrical resistance layer 56. . The backing roller 52 is configured as a heat-resistant rubber roller, for example, and the heat roller 50 is brought into pressure contact with such a heat-resistant roller.

Referring to FIG. 4, the inside of the recording paper ejecting section 32 is shown in an enlarged manner cut out from the side in the same manner as in FIGS. 2 and 3. This is different from the case shown in FIG. That is, FIG. 4 shows the inside of the recording paper discharge section 32 cut open at one end surface side of the heat roller 50. As shown in FIG. Figure 4 shows the heat roller 5.
A power supply mechanism 58 for the electrical resistance layer 56 of 0 is shown, and this power supply mechanism 58 includes a bracket member 60 made of an insulating material supported by the opening/closing frame 36, and the bracket member 60 includes a bracket member 60 having one end portion of the heat roller 50. A substantially square-shaped cut portion partially surrounding the circumference is formed, and a substantially square-shaped conductive member 62 is attached to this cut portion. Two recesses (not visible in FIG. 4) are formed on the V-shaped inner surface of the conductive member 62, that is, the surface on the heat roller 50 side, and a conductor contact 64 is formed in each recess.
is slidably housed. Compression spring elements such as coil springs (not shown) are arranged on the bottom side of the recesses,
As a result, the conductive contact 64 is brought into elastic pressure contact with the surface of the electrical resistance layer 56 of the heat roller 50. In short, each conductor contact 64 is always elastically biased against the surface of electrically resistive layer 56, thereby maintaining electrical contact therebetween.

The power feeding mechanism as described above is also provided on the opposite end surface of the heat roller 50, so that the electric resistance layer 56 of the heat roller 50 is energized from an appropriate power source (not shown) through these conductive contacts. It is heated to a predetermined temperature.

What should be noted here is that two conductor contacts 64 (there may be two or more) are arranged on both end surfaces of the heat roller 50, respectively. This is because by using two or more conductor contacts 64 on each end surface side of the heat roller 50, the electrical resistance layer 5 of the heat roller 50 is
This is because generation of sparks between the contact surfaces of the conductor contactor 64 and the conductor contactor 64 can be prevented.

Specifically, foreign matter such as toner may adhere to the surface of the electrically resistive layer 56 of the heat roller 50, and if such foreign matter enters between the contact surface between the electrically resistive layer 56 and the conductive contact 64, , the contact surface of the conductor contactor 64 may be slightly lifted from the surface of the electrical resistance layer 56. In such a case, if only a single conductive contact is used on each end surface side of the heat roller 50, the electrical resistance layer 5
6 and the conductive contact 64, a high voltage is applied between the contact surfaces, and as a result, sparks can occur between the contact surfaces. However, if two or more conductive contacts are used on each end surface of the heat roller 50, it is highly unlikely that all the conductive contacts will be lifted off the surface of the electrical resistance layer 56 at the same time due to foreign matter. Since no sparks can be generated, the generation of such sparks can be prevented. Needless to say, if a spark were to occur between the contact surfaces of the electrically resistive layer 56 and the conductive contact 64, the contact surfaces would be damaged and the spark must be prevented from occurring.

In the example described above, the conductive contact 64 is attached to the heat roller 50 with a compression spring element (not shown) in its recess.
was brought into elastic pressure contact with the surface of the electrical resistance layer 56,
The conductive contactor is configured as a conductive plate spring element, and the conductive plate spring element is applied to the heat roller 5 by its own elastic force.
It may be made to be brought into elastic pressure contact with the surface of the zero electrical resistance layer 56.

Referring again to FIGS. 2 and 3, when the access cover 38 assumes its closed position as shown in FIG. is formed by a pair of guide path forming members 68 and 70. The guide path forming member 68 is supported so as to extend between both side wall surfaces of the access opening/closing cover 38, while the guide path forming member 70 is approximately the same as the guide path forming member 68.
It is supported by the opening/closing frame 36 so as to extend over the length 11. Therefore, when the access opening/closing cover 38 assumes the closed position as shown in FIG. A recording paper guide path 66 facing the nip with the backup roller 52 is formed, but when the access opening/closing cover 38 takes the open position as shown in FIG.
Only the guide path forming member 70 remains on the recording paper ejection side of the thermal transfer mechanism 48, but the guide path forming member 68 remains on the recording paper guide path 6.
6 together with the access opening/closing cover 38. Such a configuration is, for example, a thermal transfer mechanism 4.
This is preferable in that the guide path forming member 68 does not interfere with the maintenance work when accessing the part 8 for maintenance, etc.; You may also do so.

A plurality of rib elements 72 and 74 are respectively formed on both inner wall surfaces on which the guide path forming members 68 and 70 face each other when the access opening/closing cover 38 is placed in the closed position shown in FIG. A recording paper guide path 66 is formed by the top surfaces of these rib elements 72 and 74.

In this embodiment, as shown in FIG. 5A, the plurality of rib elements 72 formed on the guide path forming member 68 provide discontinuous top surfaces separated from each other, and these top surfaces are connected to the recording paper P.
It becomes a support surface for What should be noted here is that the rib elements 72 extend at a uniform inclination with respect to the traveling direction of the recording paper P, and as a result, the recording paper supporting surfaces of the plurality of rib elements 72 move as the recording paper P moves. This is to avoid constant contact with any part of the recording paper P inside. To explain in detail, in FIG. 5B, the recording paper P is as shown in FIG. 5A.
Although it is shown in a more advanced state than shown in 5th
This means that the area of the recording paper P that was in contact with the top surfaces of the rib elements 72 in the state shown in FIG. 5A is not in contact with any of the top surfaces of the rib elements 72 in the state shown in FIG. 5B. The area of the recording paper P that was in contact with the top surface of the rib element 72 in the state shown in FIG. 5A is shown as a hatched area in FIG. 5B. Of course, the same can be said of the rib elements 74 of the guide path forming member 70. In this way, any part of the moving recording paper P is prevented from constantly coming into contact with the top surfaces of the rib elements 72 and 74, that is, the recording paper supporting surface, so that the recording paper P is locally rapidly cooled. This situation will be avoided. Note that the rib elements 72 and 7
It goes without saying that in that 4 provide discontinuous recording paper support surfaces, each separated from one another, a global rapid cooling of the recording paper P can also be avoided.

The arrangement of the rib elements is not limited to that shown in FIG. 5A, but may also be arranged as shown in FIG. 6. Further, it is not necessary to obtain the recording paper supporting surface by a lip, and the small cylindrical protrusions 76 are arranged on the corresponding wall surface of the guide path forming member in the form shown in FIG. 7 or 8. The top surface of the portion 76 may form a recording paper supporting surface. In short, the arrangement of the recording paper support surface may be in any manner as long as it is possible to avoid constant contact between any part of the recording paper and the recording paper support surface.

In FIGS. 1 to 3, reference numeral 78 indicates a recording paper discharge roller assembly rotatably supported by the access opening/closing cover 38 to guide the recording paper that has undergone the heat fixing stage to its discharge port. . A gear 80 is provided at one end of the shaft of the recording paper discharge roller assembly 78, and a drive gear train 82 (FIG. 1) is provided at the side of the opening/closing frame 38, so that the access opening/closing cover 38 is closed. When gear 8
0 meshes with the drive gear train 82 and is driven.

〔Effect of the invention〕

As is clear from the above description, in the structure of the recording paper guide path according to the present invention, the guide support surface forming the recording paper guide path is formed into a plurality of discontinuous support surfaces separated from each other. Since the contact area of the recording paper with the guiding support surface of the recording paper is reduced, rapid cooling of the entire recording paper is prevented, and the contact area of the recording paper with any part of the recording paper and the plurality of discontinuous support surfaces is prevented while the recording paper is moving. By avoiding constant contact, local quenching of the recording paper is also prevented, so that condensation of water droplets on the recording paper can be effectively eliminated.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view showing, in an open state, the recording paper ejection section of an external printer in which the structure of the recording paper guide path according to the present invention is implemented when the toner recording device is configured as an external printer for a word processor, microcomputer, etc. 2 is a side view showing the inside of the recording paper ejection section of the external printer shown in FIG. 1 in detail by cutting it open from the side, and FIG. 3 is a side view corresponding to FIG. A diagram showing the opening/closing cover for accessing the paper ejection section in the open position, and FIG. 4 is a detailed side view of the inside of the recording paper ejection section of the external precipitator shown in FIG. 1, cut open from the side, similar to FIG. 2. Figure 5A is a diagram in which the incision location is different from that in Figure 2.
is a plan view showing the arrangement form of rib elements of the guide path forming member;
FIG. 5B is a plan view similar to FIG. 5A, showing the recording paper in a state where it has advanced further than in FIG. 5A;
This figure is a plan view showing a modified example of the arrangement of the rib elements in FIG. A plan view showing,
8 is a plan view showing a modification of FIG. 7, FIG. 9 is a schematic diagram showing the structure of a conventional recording paper guide path provided on the recording paper discharge side of the thermal transfer mechanism of a toner recording device, and FIG. 10 9 is a schematic diagram showing the structure of a conventional recording paper guide path, which is different from FIG.
FIG. 1 is an end view taken along line XI-XI in FIG. 1O. 30... External printer, 32... Recording paper ejection section, 3
4... Main frame, 36... Opening/closing frame, 3
8... Access opening/closing cover 48... Heat fixing mechanism, 50... Heat roller,...
...Backup roller, ...Recording paper guide path, -70...Guide path forming member, -74...Rib element, ...Small cylindrical protrusion

Claims (1)

[Claims] 1. In the recording paper guide path (66) provided on the recording paper ejection side of the heat fixing mechanism (48), the guide support surface forming the recording paper guide path is composed of a plurality of discontinuous support surfaces separated from each other. Structure of a recording paper guide path, characterized in that the discontinuous support surface is arranged to avoid constant contact with any part of the recording paper during the movement of the recording paper.