JP2014016523A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus including a configuration capable of avoiding an increase in the number of harnesses and in the size of a connector in an electrical component that is used for control on a changing phenomenon such as temperature.SOLUTION: An image forming apparatus 601 comprises a fixing device 25 performing heat-fixing of a visible image. The fixing device 25 comprises a thermoelectric conversion element 251 that performs power generation by receiving heat from a heat source H1; temperature detection means 252 that is operated by a minute discharge power using an electromotive force of the thermoelectric conversion element 251; and a wireless module 254. The thermoelectric conversion element 251, when a difference in temperature on front and rear faces of the heat sources H1 reaches a predetermined temperature difference, generates and transmits power to the temperature detection means 252 and wireless module 254; and the temperature detection means performs communication via the wireless module.

Description

  The present invention relates to an image forming apparatus, and more particularly to a control mechanism for a fixing device.

  As is well known, in an electrophotographic image forming apparatus, an electrostatic latent image formed on a photoreceptor, which is a latent image carrier, is subjected to visible image processing with toner, and the toner image is a recording medium such as recording paper. Then, a fixing process is performed in which heat and pressure are applied to obtain a copy output.

As one of apparatuses used in the fixing process, an apparatus that uses a heating roller and a pressure roller to fix a recording medium while nipping and conveying the recording medium is known. (For example, patent document 1).
The above-mentioned patent document discloses a configuration that includes a fixing roller and a pressure roller that face each other across a conveyance path of a recording medium, and melts and penetrates the toner image into the recording medium while being nipped and conveyed by both the rollers. Has been. The fixing roller is equipped with a heat source and functions as a heating roller.

In the fixing device, if the conveyance state of the recording medium is not normal, problems such as abnormal overheating occur.
Therefore, the image forming apparatus may be equipped with a configuration for managing the conveyance state of the recording medium passing through the fixing device.
The following configuration is known as a configuration for managing the conveyance state of the recording medium.
Configuration that detects the conveyance timing of the recording medium conveyed to the fixing device and judges the conveyance state from the time required for movement, and prevents normal adhesion of the recording medium after fixing to the roller circumferential surface The above-described patent document or the like is known for a structure that separates toward a position.
In the former configuration, as shown in FIG. 8, the inlet and outlet sensors arranged in the conveyance path correspond, and in the latter configuration, a separation mechanism having a separation claw capable of coming into contact with and separating from the roller peripheral surface is provided. Correspond.

In addition to the above-described configuration, the fixing device includes a power supply path to the heat source and a cleaning mechanism, and a power supply path to the maintenance management mechanism of the fixing device, and further, between the maintenance management mechanism and the control unit. Many electrical components such as signal lines are mounted.
As shown in FIG. 9, the electrical component is connected between a necessary control unit and a power supply unit via a power supply and signal harness as shown in FIG. 9.
A DC low voltage system and an AC high voltage system are used for the harness connected to the control unit and the power supply unit. The DC low voltage system is intended for the passage sensor and fixing roller temperature sensor provided in the recording medium conveyance path, and the AC high voltage system is intended for the heater, auxiliary heater, etc. used for the fixing roller. It is.

2. Description of the Related Art Conventionally, an apparatus related to an image forming process such as a fixing device is often unitized for the purpose of improving the ease of assembling an image forming apparatus into a casing and handling during replacement maintenance.
In various units that are unitized, electrical components are collectively arranged on a control board or the like, and power supply and transmission / reception between devices can be performed via connectors provided on the board.
Various unitized devices are taken out or loaded into the interior when the inside of the image forming apparatus in which these various devices are installed is opened. At this time, since the harness is also connected and separated between the connectors, the workability is not deteriorated because no connection or the like is required.

  However, there is a limit to increasing the number of harnesses for the connector. For this reason, when an increase in control items occurs in the fixing device, it may be difficult to increase signal lines for this control. In other words, the number of installation pins relative to the size of the connector is not infinite, the number of pins may not be sufficient, the external size must be increased, and a new problem of larger equipment due to the larger installation space Occurs.

Therefore, as a configuration for avoiding such an increase in harness, a configuration has been proposed in which a wireless batteryless switch that can transmit and receive signals wirelessly is used to generate power when using wireless by natural energy (for example, Patent Document 2).
The above-mentioned patent document discloses a configuration in which energy from sunlight or the like is used as a power source of a wireless batteryless switch, and an output signal from the switch is transmitted to a receiver wirelessly so that signals can be transmitted and received.

  However, since the configuration disclosed in the above-mentioned patent document does not target a fixing device having a heat source, no consideration is given to labor saving of harnesses at a location affected by heat from the heat source.

  An object of the present invention is to avoid an increase in harnesses and an increase in the size of a connector in an electrical component used in the case where control is performed for a phenomenon that changes such as temperature, in view of the problems in the conventional image forming apparatus. An object of the present invention is to provide an image forming apparatus having such a configuration.

In order to achieve this object, the present invention provides:
An image forming apparatus including a fixing device that heat-fixes a visible image,
The fixing device includes a connector that can be connected to a power supply unit to a heat source, a thermoelectric conversion element that generates power by receiving heat from the heat source, and a temperature that operates with micro discharge power using an electromotive force generated by the thermoelectric conversion element. A detecting unit and a wireless module, and the thermoelectric conversion element generates power when the temperature difference between the front and back surfaces of the heat source reaches a predetermined temperature difference, and transmits the power to the temperature detecting unit and the wireless module. Communicates via the wireless module.

  According to the present invention, since the temperature detection means and the wireless module can be operated by the electromotive force generated in the thermoelectric conversion element that generates power by receiving heat from the heat source, transmission / reception by wire can be reduced. As a result, when a part of the signal harness is connected by a connector, the number of pins and the number of harnesses in the connector affected by the heat from the heat source are suppressed, without complicating the configuration. It becomes possible to maintain the accuracy of power feeding and transmission / reception.

FIG. 2 is a schematic diagram for explaining an example of an image forming apparatus equipped with a fixing device. 1 is a block diagram for explaining a principle configuration of a fixing system used in an image forming apparatus according to an embodiment of the present invention. It is a block diagram which shows the principal part of the principle structure shown in FIG. It is a figure which shows the structure of the electrical equipment unit used for the fixing system shown in FIG. FIG. 3 is a block diagram showing a conventional example relating to a fixing system used for comparison with the fixing system shown in FIG. 2. FIG. 3 is a block diagram for explaining a modification of the main part of the fixing system shown in FIG. 2. FIG. 7 is a schematic diagram for explaining a configuration of a fixing device using a modification example of main parts shown in FIG. 6. It is a schematic diagram for explaining a configuration of a conventional example of a fixing device used in an image forming apparatus. It is a schematic diagram for demonstrating the structure of the fixing process execution part used for the fixing apparatus shown in FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 shows a color copying machine 601 which is one of image forming apparatuses.
The copier 601 includes an image forming unit including a printer 100 and a paper feed unit 200, a scanner 300, and an ADF (automatic document feeder) 400.
The scanner 300 is attached on the printer 100, and the ADF 400 is attached on the scanner 300.

The scanner 300 reads image information of a document placed on the contact glass 32 with a reading sensor (CCD in this embodiment) 36 and sends the read image information to an engine control unit (not shown). Yes.
Based on the image information received from the scanner 300, the engine controller controls four drum-shaped photoconductors 40 (K in FIG. 3) by controlling lasers and LEDs (not shown) disposed in the exposure device 21 of the printer 100. , Y, M, and C) are irradiated with laser writing light L (see FIG. 2).
By this irradiation, an electrostatic latent image is formed on the surface of the photoreceptor 40 (K, Y, M, C), and this latent image is developed into a toner image via a predetermined development process. Note that the subscripts K, Y, M, and C added after the reference numerals indicate specifications for black, yellow, magenta, and cyan.

The printer 100 includes a primary transfer roller 62 (K, Y, M, C), a secondary transfer device 22, a fixing device 25, a paper discharge device, not shown, as well as an exposure device 21 that is an exposure device. A toner supply device and a toner disposal device are also provided.
The paper feeding unit 200 includes an automatic paper feeding unit disposed below the printer 100 and a manual feeding unit disposed on a side surface of the printer 100. The automatic paper feed unit separates the three paper feed cassettes 44 arranged in multiple stages in the paper bank 43, the paper feed roller 42 that feeds transfer paper as a recording medium from the paper feed cassette 44, and the fed transfer paper. And a separation roller 45 to be fed to the paper feed path 46. Further, it also includes a transport roller 47 that transports the transfer paper to the paper feed path 48 of the printer 100.

A registration roller pair 49 is disposed near the end of the paper feed path 48 of the printer 100.
The registration roller pair 49 is formed between the intermediate transfer belt 10 as the intermediate transfer body and the secondary transfer device 22 at a predetermined timing after receiving the transfer paper sent from the paper feed cassette 44 or the manual feed tray 51. This is a member sent to the secondary transfer nip.
The registration roller pair 49 is configured so that a conveyance path from the manual feed portion can be continued.
The manual feed section includes a manual feed tray 51, a separation roller 52 that separates the transfer paper on the manual feed tray 51 one by one toward the manual feed path 53, and the like.

In the color copying machine 601, an operator sets a document on the document table 30 of the ADF 400 when copying a color image. Alternatively, after the ADF 400 is opened and a document is set on the contact glass 32 of the scanner 300, the ADF 400 is closed and the document is pressed. Then, a start switch (not shown) is pressed. Then, when a document is set on the ADF 400, the scanner 300 starts driving immediately after the document is conveyed on the contact glass 32 and then when the document is set on the contact glass 32.
When the scanner 300 is started, the first carriage 33 and the second carriage 34 travel, and the light emitted from the light source of the first carriage 33 is reflected by the document surface and then travels toward the second carriage 34. Further, after being reflected by the mirror of the second carriage 34, it reaches the reading sensor 36 via the imaging lens 35 and is read as image information.

When the image information is read in this way, the printer 100 rotates the other two support rollers while rotating one of the support rollers 14, 15, and 16 with a drive motor (not shown). Then, the intermediate transfer belt 10 that is an intermediate transfer member stretched around these rollers is moved endlessly.
Further, laser writing as described above and a development process described later are performed. Then, while rotating the photoreceptors 40 (K, Y, M, C), black, yellow, magenta, and cyan monochrome images are formed on them. These are electrostatically transferred in four colors at the primary transfer nips for K, Y, M, and C where the photosensitive member 40 (K, Y, M, and C) and the intermediate transfer belt 10 come into contact with each other, and are four colors. A superimposed toner image is obtained. A toner image is formed on the photoreceptor 40 (K, Y, M, C).

On the other hand, the paper feed unit 200 operates one of the three paper feed rollers 42 to feed the transfer paper having a size corresponding to the image information, and feeds the transfer paper to the paper feed path of the printer 100. Lead to 48.
The transfer sheet, which is a sheet of paper that has entered the paper feed path 48, is sandwiched between the registration roller pair 49 and temporarily stops. Then, the intermediate transfer belt 10 and the secondary transfer roller 23 of the secondary transfer device 22 are matched in time. To the secondary transfer nip which is a contact portion.
At the secondary transfer nip, the four-color superimposed toner image on the intermediate transfer belt 10 and the transfer paper are in close contact with each other in synchronization, and the four-color superimposed is caused by the influence of the transfer electric field and nip pressure formed in the nip. The toner image is secondarily transferred onto the transfer paper and combined with the white color of the paper to form a full color image.

  The transfer paper that has passed through the secondary transfer nip is fed into the fixing device 25 by the endless movement of the transport belt 24 of the secondary transfer device 22. The full color image is fixed by the action of the heating roller 26 of the fixing device 25 and the pressure applied by the pressure roller 27, and then the paper discharge tray 56 provided on the side surface of the printer 100 via the discharge roller 55. Discharged to the top.

FIG. 2 is a block diagram for explaining the configuration of the electrical unit 250 provided in the fixing device 25.
In the figure, to the electrical unit 250, a heater H1, which is a heat source of the heating roller 26 used in the fixing device 25, can be supplied with power from an external AC power source via a connector 250B provided on a control board 250A used in the electrical unit 250. It is provided in the state.

On the other hand, the electrical unit 250 operates with a thermoelectric conversion element 251 that generates power by receiving heat from a heat source disposed in the heating roller 26, and a micro discharge power using an electromotive force generated by the thermoelectric conversion element 251. A temperature detection unit 252, sensors 253, and a wireless module 254 are provided.
An inlet sensor 253A and an outlet sensor 253B corresponding to the temperature detection means 252 and sensors are installed at necessary places in the fixing device, and are connected to the control board 250A side via a harness.

  As shown in FIG. 3, the thermoelectric conversion element 251 is an environmental power generation element that generates an electromotive force due to a temperature difference between the inside and outside, such as the Seebeck effect. In the case of this embodiment, the temperature difference between the inside and outside is 10 ° C. An element capable of generating power of about 100 μW at a time exceeding this value is used.

As the temperature detection means 252, a thermistor is used, and temperature management of the heat source is executed. As the temperature detecting means 252, as the means for detecting the state, an inlet sensor 253A and an outlet sensor 253B for monitoring the conveyance state of the recording medium are also used.
When monitoring the conveyance state of the recording medium, the time for the recording medium to move between both sensors is counted. When this time is longer than a predetermined time due to the size of the recording medium or when a detection signal cannot be obtained, a warning is given as a conveyance error.

A thermoelectric conversion element 251 is connected to the temperature detection means 252 and the inlet and outlet sensors 253A and 253B, and is operated by an electromotive force from the thermoelectric conversion element 251 as shown in FIG. .
The thermoelectric conversion element 251 is connected to a wireless module 254 that can be driven with low power consumption, in addition to the detection means 252 and the inlet and outlet sensors 253A and 253B described above. The electromotive force is supplied from the thermoelectric conversion element 251.

The wireless module 254 is connected to the temperature detecting means 252 and the inlet and outlet sensors 253A and 253B by a harness.
As the wireless module 254, for example, a member that constitutes a batteryless and cableless communication means is used, as is known from a wireless module manufactured by “En Ocean”.
The wireless module 254 can communicate data from various detection means and sensors to the control unit on the image forming apparatus side in a cableless state every predetermined time as well as when the thermoelectric conversion element 251 generates power.
The signals from the inlet and outlet sensors 253A and 253B for monitoring the conveyance state of the recording medium are transmitted not only at the predetermined time described above but also when the inlet sensor 253A is activated. When timing is started with the transmission as a reference, the conveyance state can be determined based on the time until the signal from the outlet sensor 253B is received.

FIG. 4 is a view showing the arrangement of the substrates constituting the electrical unit 250 equipped with the thermoelectric conversion element 251 and the wireless module 254.
In the figure, the electrical unit 250 includes a heat shield plate 260 facing the heating roller 26 provided in the fixing device 25, and a thermoelectric conversion is provided on the surface of the heat shield plate 260 facing the heating roller 26. Element 251 is arranged.

  A printed circuit board PB forming a control board 250A is disposed on the back surface of the heat shield plate 260, that is, the back surface opposite to the heating roller 26. , And harnesses connected to the inlet and outlet sensors 253A and 253B, respectively.

  The thermoelectric conversion element 251 generates a temperature difference between the front and back surfaces when the back side of the surface facing the heating roller 26 is in contact with the heat shield plate 260, and when this temperature difference reaches a predetermined value. It is designed to generate electricity.

In the present embodiment, the number of harnesses to be connected between the electrical unit 250 and the control unit is reduced by using the wireless module 254 that uses the electromotive force in the thermoelectric conversion element 251.
In particular, in a connector used for harness connection, it is possible to eliminate the need to increase the number of terminals.

FIG. 5 is a schematic diagram showing a configuration of a conventional electrical unit, which is compared with a connector (shown as a drawer connector in the drawing) provided in the electrical unit (indicated by reference numeral 250 ′ for convenience) in FIG. In the case shown in FIG. 4, it can be seen that the number of connector terminals, in particular, the DC system low voltage and signal harnesses are reduced.
In the present embodiment, as shown in FIG. 2, it is only necessary to provide a connector terminal for only the power supply path to the heat source corresponding to the AC high voltage system as the harness used for the connector.

Next, a modification of the main part of the electrical unit shown in FIG. 2 will be described.
The configuration shown in FIG. 6 is characterized by the power generation mechanism in the electrical unit 250 shown in FIG.
That is, in addition to the thermoelectric conversion element 251, the photovoltaic device 270 is provided, and both these members are connected to an electricity storage device, so-called battery 271.

FIG. 7 is a view showing the arrangement of the boards constituting the electrical unit 250 shown in FIG.
In the drawing, the electrical unit 250 includes a heat shield plate 260 ′ that faces the heating roller 26 provided in the fixing device 25.
Unlike the case shown in FIG. 4, the heat shield plate 260 ′ shown in FIG. 4 is partially bent and formed into an angle to secure incident light to the photovoltaic device 270. Regarding securing of incident light, although not shown, a light guide member or the like may be provided.

A printed circuit board PB serving as a control board is disposed on the back surface of the heat shield plate 260 ′, that is, the back surface opposite to the heating roller 26. The printed circuit board PB is connected to the thermoelectric conversion element 251 and the wireless module 254. A power storage bias 271 is provided.
The storage bias 271 stores the electromotive force from the thermoelectric conversion element 251 and the photovoltaic device 270, and supplies power so as to operate the wireless module 254 and the detection means and various sensors as in the case shown in FIG. It is like that.
Similarly to the case shown in FIG. 4, the wireless module 254 is wired with inlet and outlet sensors 253A and 253B, respectively.

In the above configuration, power can be supplied by self-power generation by adding heat from the heating roller 26 and / or external light.
In particular, since the electromotive force from the thermoelectric conversion element 251 and the photovoltaic device 270 can be used for signal transmission / reception, if exposure of the coating occurs due to the influence of heat, there is an adverse effect such as a short circuit due to contact between the conductor and the peripheral portion. This makes it possible to reduce the number of transmission / reception harnesses that are likely to invite. Furthermore, the size of the connector can be reduced by reducing the number of connector terminals. As a result, it is possible to maintain the accuracy of power supply and transmission / reception without increasing the number of harnesses and the number of pins of the connector at the location affected by the heat from the heat source.

25 Fixing device
250 Electrical unit 251 Thermoelectric conversion element 252 Temperature detection means 253 Sensor 254 Wireless module 260, 260 ′ Heat shield plate 270 Photoelectric power generation device 271 Power storage device
601 copier

JP 2006-256704 A

Claims (5)

An image forming apparatus including a fixing device that heat-fixes a visible image,
In the fixing device,
A thermoelectric conversion element that generates power by receiving heat from a heat source;
A temperature detecting means and a wireless module that operate with a micro discharge power using an electromotive force generated by the thermoelectric conversion element;
When the temperature difference between the front and back surfaces of the heat source reaches a predetermined temperature difference, the thermoelectric conversion element generates power and transmits power to the temperature detection unit and the wireless module, and the temperature detection unit communicates via the wireless module. An image forming apparatus.   The thermoelectric conversion element is attached to a surface of a heat shield member arranged to face the heat source, and the temperature detecting means and the wireless module are respectively attached to the back surface of the heat shield member facing the heat source. The image forming apparatus according to claim 1, wherein: In the fixing device,
A thermoelectric conversion element and a photovoltaic device that generate electricity by receiving heat from a heat source; and
An electricity storage device for storing electromotive force from the photovoltaic device;
A temperature detecting means and a wireless module that operate with a micro discharge power using an electromotive force generated by the thermoelectric conversion element;
The thermoelectric conversion element is attached to a surface of a heat shield member disposed to face the heat source, and generates electric power when the temperature difference between the front and rear surfaces of the heat source reaches a predetermined temperature difference and stores the electric power in the power storage device. The image forming apparatus according to claim 1, wherein power is transmitted to a temperature detection unit and a wireless module, and the temperature detection unit communicates via the wireless module.   The thermoelectric conversion element is characterized in that a side of the heat shield member facing the heat source is exposed, and a back surface of the side facing the heat source is in contact with the heat shield member to maintain a temperature of about room temperature. The image forming apparatus according to claim 2.   5. The image forming apparatus according to claim 1, wherein the wireless module transmits and receives a signal from a detection member including the temperature detection unit to an image formation control unit.

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