JPH11282306A - Image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image recording device capable of responding the speed divergence due to slipping or the like, and capable of setting the conveying speed to an aimed value, without depending on the working accuracy of the fixing roller. SOLUTION: An image recording device is provided with a fixing roller 14 and a detecting sensor 27 on the downstream side of a pressing roller 15 in the paper sheet conveying direction, and further provided with a fixing motor consisting of a stepping motor for independently driving the fixing roller 14. A paper sheet of a prescribed length is passed through a fixing part 9, and the passing time of the paper sheet is obtained on the basis of the detecting signal of the detecting sensor 27 to display it on an operation part. Seeing this display, a user confirms whether or not the passing time is within a prescribed range. When it is within the prescribed range, it is made that the setting is completed. When it is not within the prescribed range, adjusted data are input through the keyboard of the operation part to reset the exciting time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image recording apparatus applied to a facsimile machine, a multifunction machine, a printer, a copying machine and the like.

[0002]

2. Description of the Related Art FIG. 4 is a side view showing the structure of an electrophotographic facsimile apparatus. 1 is a main body of the facsimile apparatus, 2 is a photoreceptor, 3 is a cleaning unit, and 4 is a photoreceptor drum 2. A charging unit charged to a potential;
An optical writing unit for scanning the charged photoconductor 2 with a laser beam, a developing unit 6 for developing an electrostatic latent image formed on the photoconductor 2 to form a toner image, and a developing unit 6 for applying toner to the developing unit 6 A toner magazine 8 to be supplied is composed of a roller body in contact with the outer peripheral surface of the photoreceptor 2, and a transfer unit for transferring a toner image onto a sheet. A pressurizing and heating sheet 9 fixes the toner image on the sheet. A fixing unit 10 for storing the paper P and transporting the paper P toward the transfer unit 8; a reading unit 11 for transporting the original and reading the image of the original; 1 shows an operation unit for inputting various control signals or data.

FIG. 5 is a perspective view showing the construction of a main part of a conventional fixing unit and a driving mechanism of the fixing unit. Reference numeral 13 denotes a main motor, 14 denotes a fixing roller provided with a heater inside, and 15 denotes a pressure applied to the fixing roller 14. , A press roller, a discharge roller, a gear 17 provided on a side portion of the fixing roller 14, and a gear 18 provided on a support shaft of the discharge roller 16. The rotation of the main motor 13 is transmitted through a plurality of transmission gears to a rotation transmission system to the photoconductor 2, the developing unit 6 and the transfer unit 8, and to the gear 17 and the gear 18, and the photoconductor 2, the development unit 6, and the transfer unit 8 , The fixing roller 14 and the carry-out roller 16 rotate synchronously. Further, the fixing roller 1
4, the pressure roller 15 is configured to rotate in accordance with the rotation.

[0004] The paper carrying the toner image is pressed and heated when passing through the nip between the fixing roller 14 and the pressure roller 15, and is conveyed while fixing the toner image on the paper. Further, the sheet that has passed through the nip between the fixing roller 14 and the pressure roller 15 is discharged to the outside of the apparatus main body 1 by the discharge roller 16.

[0005] Other prior arts of this type of apparatus are disclosed in JP-A-6-80273 and JP-A-6-2802.
There is a technique described in Japanese Patent Application Laid-Open No. 30700 and Japanese Patent Application Laid-Open No. Hei 2-129683.

In Japanese Patent Application Laid-Open No. 6-80273, a transfer paper deflection detection sensor is provided in a transfer path between a photoreceptor of a transfer paper and a registration roller or a fixing roller. From the difference between the deflection of the transfer paper and the appropriate amount of deflection, the speed of the registration roller or the fixing roller required to eliminate the difference is calculated, and the V driven at a predetermined speed provided at the shaft end of these rollers. It is described that one of the two-split V-pulleys on which a belt is hung is moved so that the roller speed is set to a speed at which an appropriate deflection can be obtained.

Japanese Patent Application Laid-Open No. 6-230700 discloses a first detecting means for detecting the leading edge of a sheet on the upstream side and the downstream side of a sheet conveying device to a fixing heat roller and on the downstream side of the fixing heat roller, respectively. , The second detection means and the third
Detecting means, receiving a detection signal from each detecting means,
The control output is sent to the driving system of the fixing heat roller so that the sheet feed speed detected by the second detection unit and the third detection unit is equal to the sheet feed speed detected by the first detection unit and the second detection unit. An image forming apparatus provided with a controller for sending is described.

Japanese Patent Application Laid-Open No. 2-129683 discloses that a plurality of conveying means between a transfer section and a fixing section are driven and stopped in a timely manner in accordance with a conveying position of a recording material, and each conveying means is connected to a transfer section. By timely matching the speed with the fixing unit,
An image forming apparatus that achieves high speed while satisfying image quality is described.

[0009]

By the way, in an image recording apparatus using an electrophotographic system, the conveyance speed of a fixing section for heating and fixing the toner transferred from a photoreceptor onto a sheet to the sheet greatly affects the image quality. Exert. Conventionally, only the diameter and the number of rotations of the fixing roller 14 are managed (ideal values) with respect to the transport speed of the fixing unit 9. actually,
Since the paper is conveyed at a speed lower than the target speed due to slippage during the fixing conveyance, the paper loops between the transfer unit 8 and the fixing unit 9.

Here, the image on the sheet between the transfer section 8 and the fixing section 9 is in an unstable state in which only the toner image is placed, and the sheet is fed to the fixing section 9 in this state. If a large difference occurs between the transport speed of the fixing unit 9 and the transport speed of the transfer unit 8, an image may be formed by forming a loop more than expected between the transfer unit 8 and the fixing unit 9 or by pulling the paper. Failures such as disturbance may occur. At present, in order to reduce the variation in the transport speed, the diameter of the fixing roller is suppressed to a processing limit (± 0.03), and the variation in the transport speed is suppressed as much as possible by driving the fixing roller. However, problems such as an increase in processing cost for reducing the diameter variation, a variation in the transport speed due to the variation in the diameter, and a variation in the transport speed due to a slip at the time of fixing transport still remain.

The present invention solves such a problem and provides an image recording apparatus which can cope with a speed deviation due to a slip or the like and does not depend on the processing accuracy of a fixing roller and can set a conveyance speed to a target value. The purpose is to provide.

[0012]

In order to achieve the above object, the present invention provides an electrophotographic photosensitive member which forms an electrostatic latent image on its surface, and a method for supplying toner to the electrostatic latent image of the electrophotographic photosensitive member. Developing section for transferring the toner image on the electrophotographic photoreceptor onto a sheet, a sheet feeding section for feeding the sheet to the transferring section, and a sheet for transferring the toner image. An image recording apparatus including a fixing unit having a roller for fixing a toner image onto a sheet by applying pressure and heat, wherein a driving motor for rotating and driving the roller of the fixing unit is controlled by controlling a rotation speed of the driving motor. A control unit for adjusting the number of rotations of the roller of the fixing unit. With such a configuration, the conveyance speed of the fixing unit can be set to a target value.

Further, the present invention is characterized in that an operation unit for inputting the setting of the number of rotations of the fixing roller is provided. With such a configuration, the transport speed of the fixing unit can be adjusted by an external operation of a user or a service person.

Further, according to the present invention, a detection sensor for detecting a sheet is provided downstream of the fixing section in the sheet conveyance direction, and a passage time of a sheet having a predetermined length is obtained based on a detection signal of the detection sensor. The rotation speed of the roller of the fixing unit is adjusted so that the passing time falls within a predetermined range set in advance. With such a configuration, the passage time of a predetermined length of paper in the fixing unit can be obtained based on the detection signal of the detection sensor, so that the conveyance speed in the fixing unit can be obtained, and the conveyance speed in the fixing unit can be obtained. Is appropriate or not.

Further, the invention is characterized in that the number of rotations of the roller of the fixing section can be set according to the size or type of paper. With such a configuration, the conveyance speed of the fixing unit can be set for each sheet size and sheet type, so that higher-accuracy fixing conveyance is realized.

[0016]

An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view showing a driving system of a fixing unit in an apparatus according to an embodiment of the present invention, and reference numeral 20 denotes a fixing motor. The rotation of the fixing motor 20 is transmitted to the fixing roller 14 via a transmission gear, and the fixing roller 14 is driven to rotate. Further, the fixing motor 20 is formed of a stepping motor, and the number of rotations is determined by the time for excitation. The photoconductor 2, the developing unit 6, and the transfer unit 8 are configured to rotate using the main motor 13 as a common driving source.

FIG. 2 is a perspective view showing the structure of the fixing unit in the apparatus according to the embodiment of the present invention.
Reference numeral 22 denotes a heater installed inside the pressure roller, which indicates a pressure spring that presses the rotating shaft of the pressure roller 16 toward the fixing roller 14, and the pressure roller 16 is in contact with the fixing roller 14 while applying pressure.

FIG. 3 is a side view showing the internal structure of the fixing unit. Reference numeral 23 denotes a case on which the fixing roller 14 and its peripheral members are stored, and reference numeral 24 denotes a bottom of the case for storing the pressure roller 15 and its peripheral members. , 25 is a thermistor for detecting the surface temperature of the fixing roller 14, 26 is a thermostat for adjusting the surface temperature of the fixing roller 14, and 27 is a passage for the paper discharged from between the fixing roller 14 and the pressure roller 15. 4 shows a detection sensor for detecting.

The fixing roller 14 is rotatably fixed to the upper case 23 via a bearing, and a thermistor 25 is mounted so as to be in pressure contact with the surface of the fixing roller 14. Roller 16
Is attached. The pressure roller 15 and the pressure spring 22 are attached to the lower case 24. The fixing unit 9 is configured by fixing the upper case 23 and the lower case 24 with screws.

Next, the fixing of the toner on the sheet to the sheet will be described.

When the fixing motor 23 is driven, the rotation is transmitted to the fixing roller 14 via the gear 17, and the fixing roller 14 rotates, and the pressure roller 15 rotates together with the rotation of the fixing roller 14. Further, the rotation is transmitted to the support shaft of the discharge roller 16 via the gear 18, and the discharge roller 16 rotates in the same direction in synchronization with the fixing roller 14.
Prior to loading the paper into the fixing unit 9, a voltage is applied to the heater 21 to increase the temperature of the fixing roller, the temperature is detected by the thermistor 25, and the voltage applied to the heater 21 is turned on / off. Control to stabilize at a predetermined temperature.

The sheet on which the toner image has been transferred in the transfer section 8 is conveyed to the fixing section 9 and is heated and pressed by the fixing roller 14 and the pressure roller 15 to convey while fixing the toner on the sheet. Further, the paper conveyed by the fixing roller 14 and the pressure roller 15 enters the discharge roller 16 while pushing up the detection sensor 27, and is discharged. When the paper is pushing up the detection sensor 27, the detection sensor 27 is turned on, and when the rear end of the paper passes the detection sensor 27, the detection sensor 27 is turned off.

By the way, as described above, the transport speed may vary due to slippage during the fixing transport. In order to absorb the variation, the rotation speed of the fixing motor 20 is adjusted by sending adjustment data to a control unit provided in the apparatus main body 1 and changing a set value of the excitation time of the fixing motor 20 by the control unit. Can be.

In the apparatus of the present embodiment, in order to adjust the conveying speed of the fixing unit 9 to a predetermined speed, first, a sheet of fixed length such as a fixed size sheet is passed and the detection sensor 27 is turned on. Is obtained, and the transport time or the transport speed is displayed on the display panel of the operation unit 12. Looking at this display, it is confirmed whether or not the transport time is within a predetermined range. If the value falls within the predetermined range, the setting is completed. If not within the predetermined range, the adjustment data is input from the keyboard of the operation unit 12 to reset the excitation time. Then, after the time is set, the sheet is fed again to display the transport time or the transport speed, and it is checked whether the transport time is within a predetermined range. Such an operation is performed until the transport time falls within a predetermined range.

Such an adjustment is made for each paper size and paper type, and the excitation time is set. Here, the paper size can be automatically determined by a size detecting means provided in the paper feed cassette, but the type of the paper is set and input by the user or the serviceman by operating the keyboard of the operation unit 12. Generally, the user rarely changes the type of paper, so if the excitation time is set at the time of installation of the apparatus, there is almost no need to set it again thereafter.

As described above, according to the present embodiment, it is possible to determine whether or not the transport speed is within a normal range, based on the actual transport time in the fixing unit, and to adjust the transport speed. Because of this, it is possible to absorb variations in the transport speed without depending on the processing accuracy of the fixing roller 14. Also, it is difficult to use recycled products because it is difficult to change the fixing roller after the product is shipped, but in the present embodiment, the fixing roller 14 is not used.
Since the conveyance speed can be set even when the fixing roller 14 is replaced, it is possible to use the fixing roller 14 which has been recycled by processing such as cutting the surface of the fixing roller 14 and recoating.

[0028]

According to the present invention as described above, the difference in the transport speed between the transfer section and the fixing section is such that the image is not disturbed between the transfer paths between the transfer section and the fixing section. The conveyance speed of the fixing unit can be set so that For this reason, it is possible to suppress the variation in the transport speed of the fixing unit without depending on the accuracy of the parts as in the related art, and it is possible to reduce the processing cost of the parts. In addition, although the fixing roller to be commercialized is relatively expensive, it is possible to use a fixing roller that has been recycled by processing such as cutting and recoating of the surface, and it is possible to easily reduce the reuse of components of the fixing section. It becomes feasible at cost.

Further, since the transport time of the sheet discharged from the fixing unit can be detected based on the signal from the detection sensor, the actual transport speed can be set instead of the theoretical value, and the transfer speed between the transfer unit and the fixing unit can be set. The difference in transport speed can be reduced, and the performance of the fixing unit can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a driving system of a fixing unit in an apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a fixing unit in the apparatus according to the embodiment of the present invention.

FIG. 3 is a side view showing an internal configuration of a fixing unit.

FIG. 4 is a side view showing the configuration of an electrophotographic facsimile machine.

FIG. 5 is a perspective view showing a main configuration of a conventional fixing unit and a driving mechanism of the fixing unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Photoreceptor 6 Developing part 8 Transfer part 9 Fixing part 10 Feeding part 11 Reading part 12 Operation part 13 Main motor 14 Fixing roller 15 Pressure roller 16 Unloading rollers 17, 18 Gear 20 Fixing motor 21 Heater 22 Pressure Spring 25 Thermistor 27 Detection sensor

Claims (4)

[Claims] An electrophotographic photosensitive member that forms an electrostatic latent image on a surface thereof; a developing unit that supplies toner to the electrostatic latent image of the electrophotographic photosensitive member to form a toner image; A transfer unit that transfers the toner image onto the paper, a paper feed unit that feeds the paper to the transfer unit, and a roller that presses and heats the paper on which the toner image has been transferred to fix the toner image to the paper. An image recording apparatus comprising a fixing unit, comprising: a driving motor that drives the rollers of the fixing unit to rotate; and a control unit that controls the number of rotations of the driving motor to adjust the number of rotations of the roller of the fixing unit. An image recording apparatus characterized in that: 2. The image recording apparatus according to claim 1, further comprising an operation unit for inputting a setting of a rotation speed of the fixing roller. 3. A detection sensor for detecting a sheet is provided on the downstream side of the fixing section in the sheet conveyance direction, and a passage time of a sheet having a predetermined length is obtained based on a detection signal of the detection sensor. 3. The image recording apparatus according to claim 1, wherein the number of rotations of the roller of the fixing unit is adjusted so that a time falls within a predetermined range. 4. The image recording apparatus according to claim 1, wherein the number of rotations of the roller of the fixing unit can be set according to the size or type of paper.