JPH05139563A - Carrying belt and its manufacture, and transfer member carrying device employing carrying belt - Google Patents

Abstract

PURPOSE:To provide a carrying belt where speed fluctuation is hardly caused when the carrying belt passes a roller part to hold the carrying belt and has a sufficient tensile strength, and provide a transfer member carrying device for an image forming device employing the carrying belt. CONSTITUTION:In a transfer member carrying device 14, both ends part of a thermal-fusion type film having the specified thickness and width are laminated, and the laminated part are fused and formed thicker than other parts, and at the same time, a transfer member carrying belt 8 of endless shape where the transfer member P is capable of being mounted on the surface is provided. The thickness of a part held by an encoder roller 11 and a back-up roller 12 in the width direction of the laminated part of the transfer member carrying belt 8 is formed partially thinner than the thickness of other laminated parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless conveyor belt using a heat-fusible film, a method of manufacturing the conveyor belt, and a transfer material conveyor device using the conveyor belt. The transfer material transporting device is used in an image forming apparatus to transport printing paper, copy paper, OHP film or the like as a transfer material.

[0002]

2. Description of the Related Art Conventionally, as a transfer material conveying device for the image forming apparatus, an endless transfer material conveying belt on which a transfer material (copy paper, printing paper, OHP film, etc.) can be mounted, and the transfer material A known one is provided with a plurality of belt supporting rollers that support the material conveying belt in a predetermined shape so that the material conveying belt can be conveyed and a belt driving device that conveys the transfer material conveying belt endlessly along the plurality of belt supporting rollers. ing. As a color image forming apparatus using the transfer material conveying belt, for example, a multiple transfer type laser printer is known. In such a color image forming apparatus, a total of four photoconductor drums that respectively form electrostatic latent images of four different color toners (cyan, magenta, yellow, black) are arranged along the transfer material conveyance belt. ing. A laser scanning system and toners of different colors (cyan, magenta, yellow, and
A developing device provided with (black) is arranged.

Then, a laser beam is emitted from each laser scanning system onto each of the photosensitive drums to form a latent image. The latent image formed on each photoconductor drum is developed with toner by each developing device. The toner images of the respective colors formed on the respective photoconductor drums are sequentially superposed and transferred onto one transfer material (print paper, copy paper, OHP film, etc.) which is supported and transferred by the transfer material transfer belt. ing. The transfer material transport belt is formed in an endless shape by fusing both ends of a single film having a predetermined length and width. As a method of manufacturing such a transfer material transport belt, both ends of one heat-fusible film having a predetermined thickness and width are provided with an ultrasonic welding head and a welding member mounting surface (anvil or receiving surface). There is known a method (ultrasonic fusing method) of superposing between the upper surfaces of the bases) and applying pressure to the superposed portions while applying ultrasonic waves with an ultrasonic welding head (ultrasonic welding method).

In manufacturing the transfer material conveying belt, a heat-fusible film having a thickness of 50 to 200 μm is usually used. For example, a heat-fusible film having a thickness of 75 μm is ultrasonically fused. When joined, the thickness of the joint is about 100μ
A bond quality of about 6 Kgf / cm in tensile strength at m is obtained.

[0005]

In the multiple transfer type laser printer, while the transfer material is conveyed by the transfer material conveying belt, the four color toners are transferred between the plurality of photosensitive drums and the transfer device. Toner is transferred to form a full-color image. The fluctuation of the transfer material transport speed depends on the speed fluctuation of the transfer material transport belt, and this speed fluctuation of the transfer material transport belt affects the full-color image quality. That is, if the transfer material transport belt undergoes speed fluctuations while the transfer material moves from one transfer device to the next transfer device, the transfer material will not reach the proper position of the next transfer device, and therefore this transfer device There is a problem that the latent image formed on the corresponding photoconductor drum is transferred to a shifted position on the transfer material.

Therefore, in order to solve such a problem, an encoder roll and a backup roll for detecting the conveying speed are arranged in a state where the transfer medium conveying belt is sandwiched at a predetermined position in the width direction of the transfer medium conveying belt. The belt speed is monitored by an encoder attached to the roll shaft of the encoder roll. However, if the step difference of the joint portion of the transfer material conveying belt exceeds a certain value (95 μm), the speed of the transfer material conveying belt is changed when the encoder roll passes through the step portion. And, the step at the joint is about 100μ.
In the conventional transfer material conveying belt of m, the speed fluctuation of the belt that occurs when passing through the encoder roll exceeds the allowable value of full color image quality, and as a result, a clear full color image cannot be transferred to the transfer material. There was a point.

Therefore, in order to solve the above-mentioned problem, by adjusting the gap amount between the horn and the lower pedestal at the time of ultrasonic fusing, the entire step in the width direction of the joint portion of the transfer material conveying belt is made. It is possible to make it smaller.
Further, as described in JP-A-1-93775, it is conceivable to reduce the step by polishing the entire joint portion of the transfer material conveying belt in the width direction with emery paper. However, as described above, there is a problem in that the tensile strength of the belt is reduced if the step difference in the entire width direction of the joint portion of the transfer material conveying belt is reduced.

The speed fluctuation of the transfer material conveying belt described above occurs not only in the nipping portion of the transfer material conveying belt by the encoder roll and the backup roll but also in the nipping portion of the transfer material conveying belt by the driving roller for driving the belt and the driven roller. I have something to do. Further, the above description of the problems has been described with respect to the transfer material transport belt. However, even for a belt that transports a material other than the transfer material, a transport belt that needs to accurately control the transport speed is similar to the above. Problems arise. In view of the above circumstances, the present invention provides a conveyor belt that has a sufficient tensile strength and is resistant to speed fluctuations when the conveyor belt passes a roller portion that holds the conveyor belt, and an image forming apparatus using such a conveyor belt. It is an object of the present invention to provide a transfer material transporting device.

[0009]

Next, the structure of the present invention devised to solve the above problems will be described. The constituent elements of the present invention correspond to those of the embodiments described later. For simplification, the reference numerals of the constituent elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments. In order to solve the above-mentioned problems, the conveyor belt (8) of the first invention of the present application has a structure in which both ends of a single heat-fusible film (F) having a predetermined thickness and width are overlapped. A predetermined area portion (8b) in the widthwise middle of the overlapping portion (8a) is placed on the endless conveyor belt (8) in which the overlapping portion (8a) is fused and formed thicker than other portions. Is formed to be thinner than the thickness of other overlapping portions.

In order to solve the above-mentioned problems, in the method for manufacturing a conveyor belt according to the second invention of the present application, both ends of one heat-fusible film (F) having a predetermined thickness and width are provided. The overlapped portion (8a) is overlapped and formed to be thicker than the other portions by fusion bonding, and a predetermined area portion (8b) in the width direction middle of the overlapped portion (8a) is another overlapped portion. When manufacturing an endless conveyor belt formed to have a thickness smaller than that of the above, both end portions of a single heat-fusible film (F) having a predetermined thickness and width are superposed on the fusing member mounting surface. An ultrasonic welding head (H) placed in a combined state and placed at a position facing the fusion member mounting surface.
Manufacture of a conveyor belt for manufacturing the endless conveyor belt (8) by vibrating and fusing the overlapping portion (8a) of the film (F) placed on the fusion member mounting surface. In the method, a protruding flat surface portion having a predetermined area protruding from other portions is formed at a predetermined portion of the fusion member mounting surface, and a width direction of a superposed portion (8a) of the heat fusible film (F). A predetermined part (8b) in the middle of the
It is characterized in that a) is fused.

In order to solve the above-mentioned problems, the transfer material conveying device (14) of the third invention of the present application is provided with both ends of one heat-fusible film (F) having a predetermined thickness and width. An endless transfer material transport belt (8) on which the transfer material (P) can be mounted, and the overlapping parts (8a) are fused and formed to be thicker than other parts. A plurality of belt support rollers (9) for supporting the transfer material transport belt (8) in a predetermined shape and in a transportable manner.
A belt driving device (10) for endlessly conveying the transfer material conveying belt (8) along the plurality of belt supporting rollers (9), and a predetermined position in the width direction of the transfer material conveying belt (8). A transfer material conveying device for an image forming apparatus, comprising: an encoder roll (11) for detecting a conveying speed and a backup roll (12), which are arranged so as to sandwich a transfer material conveying belt (8). In the material conveying belt (8), the thickness of the sandwiching portion (8b) between the encoder roll (11) and the backup roll (12) in the width direction of the overlapping portion (8a) is partially different from that of the overlapping portion (8b). It is characterized by being formed thinner than the thickness of 8a).

[0012]

In the endless conveyor belt of the first invention of the present application having the above-mentioned constitution, the overlapping portions (8a) of both end portions of one heat-fusible film (F) are fused to each other. Since it is formed thicker than the portion, the overlapping portion (8a) has a large tensile strength. Since the predetermined area portion (8b) in the widthwise middle of the overlapping portion (8a) is formed thinner than the thickness of the other overlapping portion, the predetermined area portion (8b) formed thinly , Its tensile strength is reduced. However, since the area of the predetermined area portion (8b) that is thin and has low strength is a part of the middle of the overlapping portion (8a) in the width direction,
Sufficient tensile strength can be ensured for the entire overlapped portion (8a).

Further, the endless conveyor belt (8) of the first invention is used in a state of being stretched over a plurality of rollers (9) arranged in a predetermined shape. When such a conveyor belt (8) is used, a pair of rolls (11, 12 such as an encoder roll and a backup roll for detecting the speed of the conveyor belt, or a drive roll and a driven roll).
Depending on the case, there is a case where a predetermined position in the width direction of the conveyor belt (8) is clamped. In such a case, a pair of rolls (11,
If the conveyor belt (8) passing through the sandwiching portion of (12) has a partially thick portion, the conveyor belt (8) conveys the conveyor belt when the partially thick portion passes through the sandwiching portion. The speed of (8) varies. The speed fluctuation increases as the change in the thickness of the conveyor belt (8) increases. However, in the conveyor belt (8) of the present invention, the predetermined area portion (8b) in the widthwise middle of the overlapping portion (8a) is formed thinner than the other overlapping portions.
The predetermined area portion (8b) is the pair of rolls (11,
It can be configured so as to pass through the holding portion of 12). In this case, since the change in the thickness of the conveyor belt (8) passing through the sandwiched portion can be reduced, the speed fluctuation of the conveyor belt (8) can be reduced.

Further, in the above-described method for manufacturing a conveyor belt according to the second invention of the present application, a protruding flat surface portion having a predetermined area protruding from other portions is formed on a predetermined portion of the fusing member mounting surface, and the heat treatment is performed. Since the predetermined portion (8b) in the widthwise middle of the overlapping portion (8a) of the fusible film (F) is placed on the projecting flat surface portion, the overlapping portion (8a) is fused, The conveyor belt (8) of the first aspect of the invention can be easily manufactured.

In the transfer material conveying device according to the third invention of the present application, the transfer material conveying belt (8) has the encoder roll (1) in the width direction of the film overlapping portion (8a).
1) and the thickness of the sandwiching portion (8b) by the backup roll (12) are partially formed to be thinner than the thickness of the other overlapping portion (8a), the width direction of the film overlapping portion (8a) In comparison with the conventional transfer material conveying belt formed thin, the tensile strength of the belt does not decrease. Also encoder roll (11)
Rolls on the film overlapping portion (8b) which is partially formed thinner than the thickness of the other overlapping portion (8a). Therefore, since the speed fluctuation of the transfer material transfer belt (8) hardly occurs when the superposed portion of the transfer belt passes the encoder roll (11), it is possible to transfer a high quality image to the transfer material.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a multiple transfer type laser printer (image forming apparatus) to which an embodiment of a transfer material conveying apparatus of the present invention is applied. As shown in FIG. 1, the multiple transfer type laser printer M of this embodiment includes four toner image forming devices U1 to U4 which are independently provided. The toner image forming devices U1 to U4 are devices that form toner images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K).

The toner image forming devices U1 to U4 are provided with photosensitive drums K1 to K4 and laser scanning systems L1 to L4 arranged around them. Since all the laser scanning systems L1 to L4 have the same configuration, one laser scanning system L1 is used.
The laser scanning system L1 includes a semiconductor laser 1 as a laser light source, a collimator lens 2 that collects a laser beam from the semiconductor laser 1 and collimates the laser beam, and a beam from the collimator lens 2 in a scanning direction. A polygon mirror 3 for deflecting the deflected beam onto the photosensitive drum K1, and a convex lens 4 for projecting and irradiating the deflected beam onto the photosensitive drum K1.
And the cylindrical mirrors 5 and 6 for correcting the surface tilt of the polygon mirror 3. The laser scanning systems L1 to L4 are connected to an image processing device (not shown) for sending an image information signal to the semiconductor lasers 1.

Around each of the photosensitive drums K1 to K4,
Chargers K11 to K41 for charging the surface of the drum are provided. Further, each of the photosensitive drums K1 to K4
Around the area, developing devices K12 to K42 provided with toners of cyan, magenta, yellow, and black in order from the charging devices K11 to K41 toward the rotational direction of the drum, and toners on the photosensitive drums K1 to K4. Transfer devices K13 to K43 for transferring an image to a transfer sheet P as a transfer material, cleaners K14 to K44 for removing residual toner on the photoconductor drums K1 to K4, and photoconductor drums K1 to K4. Static eliminators K15 to K45 for removing the above residual charges are provided respectively. The toner image forming devices U1 to U4 respectively include the photoconductor drums K1 to K4 and the laser scanning systems L1 to L.
4, charging device K11-K41, developing device K12-K42, transfer device K13
To K43, cleaners K14 to K44, and static eliminators K15 to K45
It consists of

Below the photosensitive drums K1 to K4,
The transfer paper P is mounted on the surface of the drum K1 to K4
And an endless transfer material transport belt 8 for transporting between the transfer devices K13 to K43. The transfer material transport belt 8 has a predetermined thickness (75 mm) as shown in FIG.
(μm) and a width of one heat-fusible film are overlapped to form both ends, and the other portion (a part other than the overlapped portion is formed of one heat-fusible film) The overlapped portion 8a is formed to have a thickness (100 μm) thicker than the portion (thickness 75 μm). An inclined portion 8b having a width of about 30 mm is formed at an intermediate portion of the overlapping portion 8a, which is closer to one side in the width direction. The inclined portion 8b corresponds to a portion sandwiched by an encoder roll and a backup roll described later. The thickness of the inclined portion 8b is formed to be 95 μm, and the thickness 10 of the other overlapping portion 8a is partially formed.
It is thinner than 0 μm.

In FIG. 1, the transfer material conveying belt 8 is provided with a plurality of belt supporting rollers 9 for holding the belt 8 in a predetermined shape and supporting it so that it can be conveyed. At least one of the plurality of belt supporting rollers 9 and 9 is a belt driving device 10 for endlessly conveying the transfer material conveying belt 8 along the rollers 9 and 9.
Is linked to. An encoder roll 11 and a backup roll 12 for transport speed detection, which can sandwich the transfer material transport belt 8 at a predetermined position in the width direction, at an intermediate portion on one side in the width direction of the transfer material transport belt 8.
Are arranged. As shown in FIG. 3, the rotary shaft 11a of the encoder roll 11 is cantilevered by a support member B, and the encoder 13 is attached to the tip of the rotary shaft 11a.
Is attached. The transfer material transport belt 8, the belt support roller 9, the belt driving device 10, the encoder roll 11, the backup roll 12 and the encoder 13 constitute a transfer material transport device 14 of the multiple transfer type laser printer M.

In FIG. 1, reference numeral 16 is a paper supply means for supplying the transfer paper P to the transfer material transfer belt 8 of the transfer material transfer device 14, and reference numeral 17 is a toner image transferred onto the transfer paper P. Fixing means for fixing, reference numeral 18 is a discharging means for discharging the transfer sheet P after the fixing process, and reference numeral 19 is a cleaner for a conveyor belt for removing the toner remaining on the transfer material conveyor belt 8. Is. The toner image forming devices U1 to U4 and the components shown by reference numerals 8 to 19 and the like constitute the multiple transfer type laser printer M.

According to the transfer material conveying device 14 of the multiple transfer type laser printer M having the above-mentioned structure, the encoder roll 11 is formed on one side in the width direction of the overlapping portion 8a of the heat-fusible film. Since it rolls on the inclined portion 8b which is thinner than the thickness of the other overlapping portion 8a, the speed fluctuation of the transfer material conveying belt 8 does not easily occur when passing the encoder roll 11. Therefore, the speed of the transfer paper P does not change while the transfer paper P moves from one transfer device K13 to the next transfer device K23, and the transfer paper P is suitable for the next transfer device K23. It will reach a certain time. Therefore, the photoconductor drum K corresponding to this transfer device K23
An image can be accurately transferred onto the transfer sheet P without the latent image formed on the transfer sheet 2 being transferred to the transfer sheet P while being displaced. Transfer material conveying device 14 that the present inventor has experimented with
Then, encoder roll 11 and backup roll 12
The thickness of the transfer material transport belt 8 that passes through the sandwiching portion between and is +2
In the case of a change in step of 0 μm or less, the change in speed of the transfer material conveying belt 8 was within the allowable range. Therefore, in the present embodiment, the thickness of one sheet portion of the transfer material conveying belt 8 excluding the overlapping portion 8a is 75 μm, and the thickness of the inclined portion 8b is set to 75 μm + 20 μm = 95 μm.

Next, referring to FIGS. 4 and 5, a first embodiment of the method for manufacturing the transfer material conveying belt 8 will be described. First, both ends of a heat-fusible film F having a thickness of 75 μm are superposed on each other by 0.3 mm, and this is placed on the upper surface of the anvil, that is, the fusing member mounting surface. In this way, the heat-fusible film F is sandwiched between the upper surface of the anvil and the horn arranged above the anvil, and the ultrasonic partial amplitude: 57 μm, ultrasonic frequency: 20 kHz, horn moving speed: 17 mm / If ultrasonic welding is performed under the ultrasonic welding condition of sec, an endless belt having a joint thickness of about 100 μm can be manufactured.

By the way, with this thickness, the speed fluctuation of the belt occurs when the encoder roll passes through the joining portion, so that the width of the portion where the encoder roll passes is about 3 mm.
The joint thickness is 95 μm with emery paper over 0 mm
Polishing process until it becomes. When the tensile strength of the portion polished with this emery paper was confirmed, it was found to be about 4.0 Kgf / cm, which is a strength reduction of about 2.0 Kgf / cm compared to the tensile strength of other joints, Judging from the required strength when using the belt, there was no problem.

Next, a second embodiment of the method for manufacturing the transfer material conveying belt 8 will be described. An anvil is used in which a predetermined flat portion of the fusion member mounting surface (upper surface of the anvil) is formed with a projecting flat surface portion having a predetermined area projecting from other portions, and between the upper surface of the anvil and a horn arranged above the anvil. The heat-fusible film F is sandwiched between. At that time, a predetermined portion in the widthwise middle of the overlapping portion of the heat-fusible films is placed on the protruding flat surface portion. If ultrasonic fusion is performed in this state, it is possible to manufacture a conveyor belt in which a predetermined area in the middle of the overlapping portion in the width direction is formed thinner than the thickness of other overlapping portions. In the second embodiment of the method for manufacturing the transfer material conveying belt, it is only necessary to form a projecting flat surface portion having a predetermined area projecting from other portions on a predetermined portion of the upper surface of the anvil, and the width direction of the overlapping portions at both ends. It is possible to easily manufacture a conveyor belt in which a predetermined area portion in the middle of is formed thinner than the thickness of other overlapping portions.

Although the embodiment of the transfer material conveying device for the image forming apparatus of the present invention has been described in detail above, the present invention is not limited to the above-mentioned embodiment, and the present invention is not limited to this. Various small design changes can be made without departing from the invention. For example, the transport belt of the present invention can be used as a transport belt other than the transfer material transport device.

[0027]

In the above-mentioned conveyor belt of the present invention, the predetermined area portion in the widthwise middle of the overlapped portion is formed thinner than the thickness of the other overlapped portion. It can be configured to pass through the sandwiching portion of the pair of rolls. In this case, since it is possible to reduce the change in the thickness of the conveyor belt passing through the sandwiched portion,
It is possible to reduce speed fluctuations of the conveyor belt. Further, since the predetermined area portion formed thinly is an intermediate portion in the width direction of the overlapping portion, the strength of the end portion in the width direction of the overlapping portion does not decrease. For this reason, the probability that breakage occurs from the widthwise end of the overlapping portion is low. Further, in the method for manufacturing a conveyor belt of the present invention described above, the predetermined predetermined area portion in the widthwise middle of the overlapping portion of the heat-fusible film is formed thinner than the thickness of the other overlapping portion. The conveyor belt can be easily manufactured. Further, in the transfer material conveying device of the present invention described above, the thickness of the sandwiched portion by the encoder roll and the backup roll in the width direction of the film overlapping portion is partially formed to be thinner than the thickness of the other overlapping portion. Since the transfer material transport belt is used, the tensile strength of the belt does not decrease as compared with the transfer material transport belt in which the entire width direction of the film overlapping portion is formed thin. Also, the encoder roll rolls on the film overlapping portion that is partially formed to be thinner than the other overlapping portions, so that the speed fluctuation of the transfer material conveying belt does not easily occur when passing through the encoder roll. An accurate image can be transferred.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a multiple transfer type laser printer which is an embodiment of an image forming apparatus to which a transfer material conveying device of the present invention is applied.

FIG. 2 is a partial perspective view showing a main part of a transfer material carrying belt of the transfer material carrying device of the embodiment.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an explanatory diagram of a method of manufacturing the transfer material transport belt.

FIG. 5 is an explanatory diagram of a method of manufacturing the transfer material transport belt.

[Explanation of symbols]

F ... Heat-fusible film, P ... Transfer material (transfer paper), 8 ...
Transfer material conveying belt, 8a ... Film overlapping portion, 8b
... nip portion (belt inclined portion), 9 ... belt support roller, 10 ... belt drive device, 11 ... encoder roll,
12 ... Backup roll, 14 ... Transfer material conveying device

Claims (3)

[Claims] 1. An endless transport in which both end portions of a single heat-fusible film having a predetermined thickness and width are overlapped and the overlapped portions are fused and formed thicker than other portions. In the belt, a conveyor belt is characterized in that an intermediate predetermined area portion in the width direction of the overlapping portion is formed thinner than the thickness of other overlapping portions. 2. A heat-fusible film having a predetermined thickness and width is overlapped at both end portions, and the overlapped portion is melt-adhered to be formed thicker than the other portions and the above-mentioned superposition is performed. When manufacturing an endless conveyor belt in which a predetermined area in the middle in the width direction of the portion is formed thinner than the thickness of other overlapping portions, the fusing member mounting surface has a predetermined thickness and width. Place both ends of one heat-fusible film in a stacked state,
By vibrating an ultrasonic fusing head arranged at a position facing the fusing member mounting surface to fuse the overlapping portions of the films mounted on the fusing member mounting surface, thereby the endless In a method for manufacturing a conveyor belt for manufacturing a belt-shaped conveyor belt, a protruding flat surface portion having a predetermined area projecting from other portions is formed at a predetermined portion of the fusing member mounting surface, and the heat fusible film is superposed. A method of manufacturing a conveyor belt, comprising fusing the overlapping portion in a state where a predetermined part of the widthwise middle of the overlapping portion is placed on the protruding flat surface portion. 3. A heat-fusible film having a predetermined thickness and width is overlapped at both end portions, and the overlapped portions are fused and formed to be thicker than the other portions and transferred to the surface. An endless transfer material transport belt on which a material can be mounted, a plurality of belt support rollers that support the transfer material transport belt in a predetermined shape and enable transport, and the transfer material transport belt along the plurality of belt support rollers. A belt drive device that conveys the transfer material endlessly, and an encoder roll and a backup roll for detecting the transfer speed, which are arranged so as to sandwich the transfer material transfer belt at a predetermined position in the width direction of the transfer material transfer belt. In a transfer material conveying device for an image forming apparatus, the transfer material conveying belt includes the encoder roll and the back-up belt in the width direction of the overlapping portion. Transfer material transporting device thickness of the clamping portion due to the roll is characterized in that it is formed thinner than the thickness of the partially other overlapping portions.