JP5031380B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an apparatus including a power storage device that supplies electric power to an electric device used during image formation.

  2. Description of the Related Art Conventionally, some image forming apparatuses such as printers and copiers form an image on a sheet by an electrophotographic method. In such an image forming apparatus, when an image is formed on a sheet, an electrostatic latent image is first formed on the photosensitive drum by exposing the photosensitive drum by direct or indirect scanning means according to image information. Let it form.

  Next, the electrostatic latent image is developed with toner in a developing device to be visualized as a toner image, and then the visualized toner image is transferred to a sheet supplied from a paper feeding unit. Thereafter, the sheet is conveyed to a heat fixing device, and the toner image is fixed on the sheet as a permanent image by the heat fixing device.

  Here, in such an electrophotographic image forming apparatus, in performing an image forming process for forming an image on a sheet, the photosensitive member scanning exposure means, particularly in the case of a copying machine, the scanning means, the high pressure of the photosensitive drum. The charging means consumes a large amount of power. In addition, power consumption is also increased in a power source including a high-pressure transfer unit to a transfer sheet, a high-temperature heat fixing unit, and a sheet conveying unit. That is, in the conventional image forming apparatus, there are many electric devices that use electric power, and the power consumption of each of them is also increased.

  By the way, in the conventional image forming apparatus, when the printing speed is high and the power consumption exceeds a certain level, there is a problem that sufficient power cannot be obtained with a general power supply voltage of 100 V in Japan.

  To cope with this problem, for example, the print speed is set to be slow, or the power supply voltage is set to 200 V only from the beginning. However, if the print speed is set to be slow, the productivity of the image forming apparatus is reduced. descend. In addition, when the power supply voltage is dedicated to 200V from the beginning, another problem that the cost becomes high occurs.

  In order to solve such problems, conventionally, a power storage device is provided in addition to the main power supply device, and the power storage device supplies necessary power to electrical devices such as scanning means and high-voltage charging means for the photosensitive drum. An image forming apparatus is proposed (for example, see Patent Document 1). Further, as an image forming apparatus having such a power storage device, there is one in which a cooling unit such as a dedicated fan is provided in the power storage device in order to cool the power storage device (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-282821 JP 2005-198480 A

  By the way, in the conventional image forming apparatus, when the power storage device is provided with the dedicated cooling means, a space for arranging the cooling means and a space for bundled wires are required. Larger and more costly. Further, in an image forming apparatus that consumes a large amount of power that requires a power storage device, it is inefficient to use a cooling unit that consumes power.

  Accordingly, the present invention has been made in view of such a situation, and an object thereof is to provide an image forming apparatus capable of cooling a power storage device without using a dedicated cooling unit. is there.

The present invention relates to an image forming apparatus that forms an image on a sheet, an electric device used for image formation, a casing of the apparatus main body, and an inside of the casing, and exhausts air out of the casing. when the housing inside and a cooling unit for cooling, mounted on the outer surface of the front Kikatami body, and a power storage device supplying electric power to the electrical device, for cooling the interior of the housing by the the cooling unit along the inner wall surface of the front Kikatami body to cool the front Kikatami body by flowing air, the power storage device, is characterized in that the cooling via cooled before Kikatami body .

  Like the present invention, by cooling the power storage device attached to the outer surface of the casing of the apparatus body through the casing of the apparatus body cooled by the air flowing along the inner wall surface of the casing of the apparatus body, The power storage device can be cooled without using a dedicated cooling means.

  FIG. 1 is a diagram illustrating a schematic configuration of a printer which is an example of an image forming apparatus according to an embodiment of the present invention.

  In FIG. 1, 100 is a printer, and 101 is a printer body. An image reading unit 6 for reading a document is provided on the upper portion of the printer main body 101. Below the image reading unit 6, an image forming unit 1 and a sheet feeding device 3 that feeds the sheet S to the image forming unit 1 are provided. Here, the image forming unit 1 is provided with a photosensitive drum 1a, a developing unit 1b, a laser scanner unit 1c, a transfer / separation charger 1d, a cleaner 1e for removing residual toner on the photosensitive drum, and the like.

  Next, an image forming operation of the printer 100 having such a configuration will be described.

  When an image reading signal is output to the image reading unit 6 from a control device (not shown) provided in the printer main body 101, the image reading unit 6 reads an image. Thereafter, a laser beam corresponding to the electrical signal is irradiated onto the photosensitive drum 1a from the laser scanner unit 1c.

  At this time, the photosensitive drum 1a is charged in advance, and an electrostatic latent image is formed by irradiation with light. Then, the electrostatic latent image is developed by the developing device 1b, whereby toner is formed on the photosensitive drum. An image is formed.

  On the other hand, when a paper feed signal is output from the control device to the sheet feeding device 3, the sheet S is fed from the sheet storage units 7a to 7d. Thereafter, the fed sheet S is sent to a transfer unit constituted by the photosensitive drum 1a and the transfer / separation charger 1d in synchronization with the toner image on the photosensitive drum.

  Next, the toner image is transferred to the sheet sent to the transfer unit in this way, and then conveyed to the fixing unit 4. After that, the unfixed transfer image is permanently fixed on the sheet S by being heated and pressed by the fixing unit 4. Then, the sheet on which the image is fixed in this manner is discharged from the printer main body 101 to the discharge tray 102 by the discharge roller 5.

  In FIG. 1, 8 is a power plug, 9 is an AC outlet, and 10 is a main power supply device that supplies power to the printer main body 101. Here, the main power supply 10 is connected to a power cord 8a from an AC outlet 9 such as an office or home, and has a rectifying action from AC to DC in order to transmit power to each power unit in the printer body. I have. In general, power is supplied from the main power supply device 10 to the electrical devices necessary for the above-described image forming process, such as the laser scanner unit 1c and the high-voltage charging unit of the photosensitive drum 1a (not shown).

  Incidentally, in the present embodiment, a power storage device 11 as shown in FIG. 2 is provided outside the back surface of the printer main body 101. In FIG. 2, 14 is a screw for fixing the power storage device 11 to the outside of the back surface of the printer main body 101, 13 is connected to the main power supply device 10 through the connector 12, and the power storage device 11 is charged by the main power supply device 10. It is a power cable to make.

  Here, the power storage device 11 is provided with a capacitor composed of an electric double layer. When the printer main body 101 is not in operation and the fixing unit 4 requires a large amount of power at the first startup and immediately after the startup. Charging is performed when the document reading unit 6 is not operating within a few minutes.

  Once sufficient charging is possible, the power from the power storage device 11 can be used for the document reading unit 6 when the printer main body 101 is turned off and then restarted, and for a few minutes after the startup. it can. As a result, most of the power from the main power supply device 10 can be supplied to the fixing unit 4, and as a result, the heating temperature of the fixing unit 4 that requires a large amount of power in the startup state can be increased at high speed. The sheet on which the toner image has been successfully transferred can be fixed in a short time.

  FIG. 3 is a diagram illustrating a configuration of the power storage device 11. As illustrated in FIG. 3, the power storage device 11 includes a discharge circuit 24, a charge circuit 23, and a capacitor 25. And the discharge circuit 24, the charging circuit 23, and the capacitor 25 which comprise the circuit of the electrical storage apparatus 11 are mutually connected between the bundle lines not shown.

  In FIG. 3, reference numeral 21 denotes a power storage device housing. The power storage device housing 21 includes a charge / discharge circuit support housing 22 that supports the discharge circuit 24 and the charging circuit 23, and a capacitor support housing that supports the capacitor 25. A body 26 and an exterior cover (not shown) are attached. Here, the power storage device casing 21 is attached in contact with the outer back surface of the printer main body 101. It is more preferable that the contact area between the power storage device housing 21 and the back surface of the printer main body 101 is wider.

  Here, the charging / discharging sequence of the power storage device 11 requires that the power of the printer main body 101 requires a rated current of 1.5 A or more. Is controlled to be. Further, the power is supplied to the capacitor 25 by the charging circuit 23 during standby when the power of the printer main body 101 is less than the rated current 1.5A.

  By the way, when such charging / discharging is performed, the discharge circuit 24, the charging circuit 23, and the capacitor 25 generate heat, and this heat is supplied to the power storage device casing 21 via the charging / discharging circuit supporting casing 22 and the capacitor supporting casing 26. Heat is dissipated.

  In the present embodiment, the charge / discharge circuit support housing 22, the capacitor support housing 26, and the power storage device housing 21 are formed of a sheet metal made of a material having a high thermal conductivity of 1 W / mk or more. Therefore, the heat generated during charging / discharging is efficiently transmitted to the power storage device casing 21.

  Here, as shown in FIG. 4, the back surface of the printer main body 101 is configured, and the outer surface has three (plural) on the inner surface of the back plate 32 to which the power storage device 11 is attached as described above. A duct 31 having openings 31a to 31c is fixed by screws (not shown).

  The openings 31a to 31c are not shown in the printer main body used mainly for cooling the cleaner 1e shown in FIG. 1 arranged around the photosensitive drum and for sucking ozone generated by the transfer / separation charger 1d. It is combined with the duct of the main body of each to form each air passage.

The duct 31 is coupled to a fan unit 33 that is a cooling unit disposed inside the back plate of the printer main body 101. Air is sucked from the openings 31a to 31c from the fan unit 33 into the air passage formed by the back plate 32 and the duct 31 of the printer main body 101 and flows from the fan unit 33 to the outside of the printer main body through an exhaust port ( not shown). It is configured as follows. The air inside the printer body is cooled by exhausting air from the inside of the printer body to the outside of the printer body in this manner.

  Here, when the inside of the printer main body is cooled by the fan unit 33 which is a cooling means of the printer main body 101, air is caused to flow along the inner surface of the back plate 32 constituting a part of the inner wall surface of the casing of the printer main body 101. I am doing so. Thereby, the back plate 32 constituting a part of the casing of the printer main body 101 can be cooled. In the present embodiment, the back plate 32 is formed of a sheet metal having a high thermal conductivity of 1 W / mk or more, and thereby the back plate 32 is efficiently cooled by air suction. Is called.

By the way, in this Embodiment, the electrical storage apparatus 11 is arrange | positioned in the range of the flow path formed in the space covered with the backplate 32 and the duct 31 of the backplate outer surface, as shown in FIG. And by arrange | positioning the electrical storage apparatus 11 in such a position, the electrical storage apparatus 11 can be efficiently cooled with the cooled backplate 32. FIG. In other words, the fan unit 33 is also serves as a cooling means for cooling the power storage device 11.

  FIG. 5 is a diagram illustrating the relationship between on and off of the fan unit 33 and the temperature of the back plate 32 at a room temperature of 25 ° C. In FIG. 5, the horizontal axis indicates the temperature of the power storage device 11 and the vertical axis indicates the temperature of the back plate 32.

  Here, the back plate 32 is in a state of thermal equilibrium at 25 ° C. before the temperature rise, but when the fan unit 33 is turned off, the back plate 32 is 30 ° C. and 33 ° C. due to a rise in the temperature of the power storage device 11. C., 43.degree. C., 55.degree. C. On the other hand, when the fan unit 33 is turned on, the back plate 32 is cooled to 28.5 ° C., 31.5 ° C., 40 ° C., and 50 ° C.

For this reason, in the present embodiment , the fan unit 33 is turned on when the power storage device 11 reaches 55 ° C. due to a single temperature increase, for example, using linear approximation. Due to the cooling effect of the fan unit 33, the back plate 32 is first cooled, and the back plate 32 further charges the discharge circuit 24 and the charge via the power storage device housing 21 and the charge / discharge circuit support housing 22 of the power storage device 11. The circuit 23 and capacitor 25 are cooled to about 50 ° C.

  In this way, the power storage device 11 attached to the outer surface of the back plate 32 of the printer body 101 is cooled via the back plate 32 cooled by the air flowing along the inner surface of the back plate 32, thereby Cooling can be performed without using a dedicated cooling means. Furthermore, the power storage device 11 can be efficiently cooled by disposing the power storage device 11 in the range of the flow path formed by the space covered with the back plate 32 and the duct 31. The present invention is not limited to a multi-function machine, and can be implemented in an image forming apparatus having an appropriate configuration such as a printer, a copier, and a fax machine and an image forming apparatus using an appropriate image forming method.

1 is a diagram illustrating a schematic configuration of a printer that is an example of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a power storage device provided in the image forming apparatus. FIG. 6 illustrates a structure of the power storage device. The figure which shows the duct and fan unit which were attached to the back inner side of the said image forming apparatus. The figure explaining the relationship between the temperature of the back surface of the said image forming apparatus, the temperature of an electrical storage apparatus, and fan unit on, off.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image formation part 8 Power plug 9 AC outlet 10 Main power supply device 11 Power storage device 21 Power storage device housing 22 Charge / discharge circuit support housing 23 Charging circuit 24 Discharge circuit 25 Capacitor 26 Capacitor support housing 31 Duct 32 of body cooling means Face plate 33 Fan unit 100 Printer 101 Printer body

Claims (4)

In an image forming apparatus for forming an image on a sheet,
Electrical equipment used during image formation;
A housing of the device body;
Disposed in the housing, a cooling unit for cooling the interior of the housing by venting the air out of the housing,
Attached to the outer surface of the front Kikatami body, and a power storage device supplying electric power to the electrical device,
Wherein when the inner housing is cooled, the along the inner wall surface of the front Kikatami body by the cooling unit to cool the front Kikatami body by flowing air, the power storage device, via the cooled pre Kikatami body An image forming apparatus that is cooled. Between the front Kikatami body, comprising a duct which forms a space in which air for cooling the pre Kikatami body is flow,
The image forming apparatus according to claim 1, wherein the power storage device is disposed at a position corresponding to the space.   The image forming apparatus according to claim 2, wherein the power storage device is provided on an outer surface of a back plate constituting a back surface of the device main body, and the duct is provided on an inner surface of the back plate. The image forming apparatus according to housing in any one of 3 claims 1, characterized in that formed in the high thermal conductivity material of the front Kikatami body and the power storage device.

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