JPH10282821A - Device and method for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the function and performance which have not been achieved in an ordinary device due to an insufficiency of power and to shorten a warm-up period by providing an auxiliary energy source, as an energy source for energizing a fixing means, besides a main power source. SOLUTION: As the energy source for energizing the fixing part 4, an auxiliary power source 11, as the auxiliary energy source, is provided besides the main power source 10. The auxiliary power source 11 is a secondary battery which has no electric capacity just after the installation of a main body device, and, therefore, it has to be charged from the main power source 10. During the initial start-up and a printing operation, power is necessary for the operations, it is charged when the main body device is out of service. Once it is charged sufficiently, power from both the main power source 10 and the auxiliary power source 11 are used and, thus, a raising of the temperature by heating of the fixing part 4 which requires the largest amount of power during the start-up of the main body can be speeded up when the power source of the main body device is turned off and then it is started up again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer or a copying machine having a fixing means for thermally fixing a toner image, and an image forming method for such an apparatus.

[0002]

2. Description of the Related Art In electrophotographic printers and copiers,
The image information is directly or indirectly exposed to the photoconductor by a scanning unit, an electrostatic latent image is formed on the photoconductor, and a latent image is visualized as a toner image by a developing device thereon.

Next, image formation is performed by a process in which a toner image is transferred onto a sheet supplied from a sheet feeding unit, the sheet passes through a heat fixing device, and the toner image is fixed as a permanent image.

In such an image forming process, a photoconductor scanning exposure unit, particularly, in the case of a copying machine, a document information scanning unit, a photoconductor high-voltage charging unit, a high-pressure transfer unit to a transfer sheet, and a high-temperature heat fixing unit Further, it is characterized in that there are many places where electric power is used in all parts from the power source including the sheet conveying means, and the power consumption of each part is considerably large.

Conventionally, in an electrophotographic printer or copier, if the power consumption of a device having a high print speed exceeds a certain level, the power supply voltage is generally 100 in Japan.
V may not be able to obtain enough power,
In this case, a method of setting a low printing speed or a method of exclusively using a power supply voltage of 200 V from the beginning is used.

[0006]

In this type of printer and copier, the power required by the apparatus tends to increase as the printing speed is increased and full color printing is performed. Setting the print speed to a low speed as described above is a means inconsistent with the purpose of speeding up the printer in the first place, and cannot be used as an essential problem solving method.

[0007] In addition, the method of setting the power supply voltage to a higher voltage specification, for example, in the case where a 100 V power supply is generally used in Japan, requires a special construction work at the installation place, which greatly restricts the installation place. Further, a power supply device that supports a higher voltage is required, which is costly.

Another problem is that when the temperature of the fixing device, which particularly requires power, is increased, it takes a considerable amount of time to increase the temperature to a certain level only by a conventional single power supply. This becomes more conspicuous when the image forming apparatus is usually operated at high speed or full color. In particular, the time required from a completely cooled state may be 10 minutes or more in an actual high-speed copying machine.

The present invention has been made under such circumstances, and provides an image forming apparatus and an image forming method capable of exhibiting functions and performances that could not be realized by ordinary apparatuses due to power shortage. It is intended to do so.

[0010]

In order to achieve the above object, according to the present invention, an image forming apparatus is configured as described in the following (1) to (5), and an image forming method is configured as described in the following (6). Configure.

(1) An image forming apparatus having a fixing means for heating and fixing a toner image, wherein an image is provided with an auxiliary energy source other than a main power source as an energy source for energizing the fixing means. Forming equipment.

(2) The image forming apparatus according to (1), wherein the auxiliary energy source is a secondary battery.

(3) The image forming apparatus according to (1), wherein the auxiliary energy source is a primary battery.

(4) The image forming apparatus according to (1), wherein the auxiliary energy source is a heat storage unit.

(5) The image forming apparatus according to any one of (1) to (4), wherein the auxiliary energy source is used together with a main power supply in a specific operation mode.

(6) An image forming method in an image forming apparatus for heating and fixing a toner image, wherein fixing is performed by using an auxiliary energy source together with a main power supply in a specific operation mode.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail below with reference to an example of a digital multifunction peripheral. Note that the present invention is not limited to a multifunction peripheral, but can be implemented in an appropriate image forming apparatus such as a printer, a copier, and a facsimile. Further, the present invention is not limited to the apparatus and can be implemented in the form of an image forming method.

(First Embodiment) FIG. 1 is a sectional view showing the structure of a "digital multifunction peripheral" according to a first embodiment. In FIG. 1, reference numeral 1 denotes an electrophotographic image forming unit, 2 denotes a paper transport unit,
3 is a paper feeding unit, 4 is a fixing unit, 5 is a paper discharging unit, 6 is a document reading unit, 7a to 7c are a paper feeding cassette, 8 is a power plug, 9 is an AC outlet, 10 is a main power supply device, and 11 is an auxiliary. 1 shows a power supply.

In the present embodiment, the image forming section 1 includes a laser scanner, a photosensitive member, a developing device, a charging device, and a transfer device, and the paper is conveyed from the paper feeding portion 3.

In the case of ordinary document copying, image information read and image-processed by the document reading unit 6 is converted into a laser emission signal, and a light beam from the laser scanner is applied to the photosensitive member of the image forming unit 1. Irradiated to. Next, a toner image is formed on the photoconductor by a developing device,
It is transferred onto the conveyed paper. The paper is supplied from paper feed cassettes 7a to 7c, and is conveyed toward the image forming unit 1 by the paper feed unit 3. In the image forming unit 1, an image is formed by an electrophotographic process. A toner image is formed thereon and sent to the fixing unit 4.

The fixing section 4 melts and fixes the sheet on which the toner image is deposited by heat and pressure, sends the sheet to the sheet discharge section 5, and outputs the sheet outside the apparatus.

The power consumed in the above-described process is usually supplied from the main power supply 10 to each power unit. Main power supply 10
Is connected by a power cord from an AC outlet 9 in an office or home, and has a rectifying function from AC to DC in order to transmit power to each power unit in the machine.

Auxiliary power supply 1 which is a feature of this embodiment
Reference numeral 1 denotes a secondary battery, which has no electric capacity immediately after the main unit is installed, and must be charged from the main power supply 10. However, power for operation is required at the first start-up or during a printing operation. For this reason, the main unit is charged during non-operation.

Once the battery is sufficiently charged, the main power source 10 is turned off the next time the main unit is turned off and restarted.
By using both of the power from the power supply and the auxiliary power supply 11, the heating and heating of the fixing unit 4 requiring the largest amount of power when the main body is started can be performed at high speed.

FIG. 2 shows a power supply sequence of the main power supply 10 and the auxiliary power supply 11. As shown in the figure, the secondary battery serving as the auxiliary power supply 11 is charged at the time of standby in which the power supply amount of the main power supply 10 is relatively small. The fixing unit 4 is energized by the auxiliary power supply 11 to increase the temperature at a high speed.

According to the present embodiment, it has been confirmed that the temperature adjustment (hereinafter referred to as temperature adjustment) of the fixing unit 4 can be performed in about half the time as compared with the conventional apparatus.

(Embodiment 2) In the image forming apparatus of the normal electrophotographic system, the temperature control of the fixing unit 4 is a problem for increasing the printing speed. This is because heat is deprived of the sheet when the sheet onto which the developer has been transferred is fused and fixed, and if the number of sheets that can be fixed per unit time is increased, the temperature control of the fixing unit 4 cannot be performed in time.

Therefore, in order to maintain the temperature control of the fixing unit 4, more electric power is required.

FIG. 3 is a diagram showing a power supply sequence of the digital multi-function peripheral according to the second embodiment. In this embodiment, as shown in FIG. 3, an operation mode for temporarily printing at a higher speed than the normal printing speed is provided, and the auxiliary power supply 11 is used to compensate for the power shortage at that time. .

In the case of a normal print speed, all necessary power is supplied from the main power source, but when the user selects the high-speed print mode and performs printing, the operation sequence of the entire apparatus corresponds to the high-speed print mode. And the power is supplied from the auxiliary power supply 11 at the same time. However, the high-speed print mode is effective only while the electric capacity in the auxiliary power supply 11 remains,
If a print operation request is made even when the electric capacity in the auxiliary power supply 11 becomes lower than a certain level, the sequence automatically returns to the normal print speed sequence.

(Embodiment 3) An electrophotographic image forming apparatus is characterized in that printing can be performed on various types of materials. However, since the heat capacity differs depending on the material, the same printing speed is used for all materials. It is difficult to maintain.

FIG. 4 shows a power supply sequence in the third embodiment. In this embodiment, as shown in the figure, when printing a material having a large heat capacity, the auxiliary power supply 11 is used.
The print speed can be maintained by using the power from the printer together.

(Embodiment 4) In general, materials having a large heat capacity include cardboard and OHP films. When a user selects such a material at the operation unit, electric power is supplied from the auxiliary power supply 11 to the fixing unit 4. You. At this time, the power supplied from the auxiliary power supply 11 is automatically adjusted according to the number of prints and the type of material.

FIG. 5 is a diagram showing a power supply sequence in this embodiment. According to this example, the operation is performed so as to supply a larger electric power when printing on an OHP film than on thick paper.

In this case, as in the case of the second embodiment, a certain printing speed can be maintained as long as the electric capacity of the auxiliary power supply 11 continues. When the remaining capacity becomes insufficient, the operation is switched to the low-speed printing operation sequence.

(Embodiment 5) In this embodiment, the auxiliary power supply 11
By using a primary power supply instead of a rechargeable secondary battery, power can be supplied from the auxiliary power supply 11 without a time lag when power is not sufficient with the main power supply 10 alone.

FIG. 6 is a diagram showing a power supply sequence in this embodiment. In this embodiment, since there is no need to charge the auxiliary power supply 11, power can be supplied from the auxiliary power supply 11 immediately after the main device is started, and the warm-up time can be shortened from the beginning.

(Embodiment 6) As described above, in each embodiment, the heat generation amount of the fixing device is a factor due to the rise time of the image forming apparatus main body, the printing speed, and the print material dependency. As a method for solving these problems, a sixth embodiment provides a heat storage device instead of an auxiliary power supply.

The heat storage device accumulates by using the excess heat of the fixing device generated when there is no printing operation, and is used when the main device is started, when the printing speed is increased, or when printing is performed using a material having a large heat capacity. And a function of supplying heat to the fixing device.

According to this embodiment, the same effects as those of the other embodiments can be obtained. In addition, since the heat storage device, which is an auxiliary energy source, does not require any particular energy, energy can be saved.

[0041]

As described above, according to the present invention,
By separately mounting an auxiliary energy source in addition to the main power source as an energy source for energizing the fixing unit for heat fixing,
It is possible to exhibit functions and performances that could not be realized with ordinary devices due to power shortage.

Further, according to the second and fifth aspects of the present invention, since the auxiliary energy source is a secondary battery, the image forming apparatus can be charged when power demand is small, and the main body is particularly large. It can be discharged as needed when power is needed.

According to the third and fifth aspects of the present invention,
The auxiliary energy source is a primary battery,
The power of the image forming apparatus main body can be assisted without a time lag due to charging.

According to the fourth and fifth aspects of the present invention, since the auxiliary energy source is a heat storage device, the heat storage can utilize the excess heat of the fixing means and the like, thereby saving energy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a first embodiment.

FIG. 2 is a diagram illustrating a power supply sequence according to the first embodiment.

FIG. 3 is a diagram illustrating a power supply sequence according to the second embodiment.

FIG. 4 is a diagram illustrating a power supply sequence according to a third embodiment.

FIG. 5 is a diagram illustrating a power supply sequence according to a fourth embodiment.

FIG. 6 is a diagram illustrating a power supply sequence according to a fifth embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrophotographic image forming unit 4 fixing unit 10 main power supply 11 auxiliary power supply

Claims (6)

[Claims] 1. An image forming apparatus comprising a fixing unit for heating and fixing a toner image, wherein an auxiliary energy source other than a main power source is provided as an energy source for energizing the fixing unit. Characteristic image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the auxiliary energy source is a secondary battery. 3. The image forming apparatus according to claim 1, wherein the auxiliary energy source is a primary battery. 4. The image forming apparatus according to claim 1, wherein the auxiliary energy source is a heat storage. 5. The image forming apparatus according to claim 1, wherein the auxiliary energy source is used together with a main power supply in a specific operation mode. 6. An image forming method in an image forming apparatus for heating and fixing a toner image, wherein fixing is performed by using an auxiliary energy source in combination with a main power supply in a specific operation mode. Image forming method.