JP5747676B2 - Power generation device, power supply device, and image forming apparatus - Google Patents

Description

  The present invention relates to a power generation device, a power supply device, and an image forming apparatus.

  In office devices such as LP (Laser Printer) and MFP (Multi Function Printer), it is desired to reduce power consumption not only during normal operation but also in a standby state. In particular, it is desirable to reduce the power consumption in the standby state as much as possible, and the measures such as sleep mode, etc., stop power supply and lower the clock frequency for functions not used in the standby state. Has been made.

  On the other hand, in recent years, energy generation technology (hereinafter referred to as energy creation technology) that generates power by itself and supplies power has attracted attention. Examples of the power generation method applied to the energy generation technology include a method using a solar cell and a fuel cell, a method of generating power using power conversion and thermoelectric conversion, and the like. A technique for using this energy generation technology to supply power in the standby state of the apparatus and reducing the power consumption of the commercial power supply in the standby state to substantially zero has been considered and is already known.

  For example, it has been proposed to apply energy creation technology using thermoelectric conversion elements to office equipment. Since the thermoelectric conversion element can generate electric power using the exhaust heat of the apparatus, the thermoelectric conversion element is attracting attention as a device capable of reusing energy.

  Patent Document 1 discloses a copying machine in which a structure is installed so as to surround a fixing device, a thermoelectric conversion element is disposed therein to collect waste heat of the fixing device, and the collected waste heat is electrically converted to convert the low temperature portion. Is disclosed that can be created and maintained without the use of other energy.

  However, the power generation by the conventional thermoelectric conversion element is not sufficient in energy conversion efficiency, and using only this conventional thermoelectric conversion element to cover the power consumption in the standby state of office equipment such as LP and MFP, There was a problem that it was difficult.

  Further, Patent Document 1 described above collects exhaust heat of the fixing device and converts it into electricity to create a low temperature portion, and is not adaptable to power supply in a standby state.

  This invention is made | formed in view of the above, Comprising: It aims at producing | generating electric power more efficiently using a thermoelectric conversion element.

In order to solve the above-described problems and achieve the object, the present invention provides a thermoelectric conversion element that converts a temperature difference between the first surface and the second surface that are opposite to each other into a voltage, and sunlight. a first heating section for heating the first surface, in close contact with the second surface, the thermoelectric material having a Thomson effect for performing heat absorbing or dissipating by passing a current between two points with a temperature difference, the thermoelectric conversion A second heating unit that heats the fourth surface on the back surface side of the third surface of the thermoelectric material that is in close contact with the second surface of the element using sunlight, the third surface, and the fourth surface; And a current supply unit that supplies current in a direction in which the thermoelectric material absorbs heat, and a cooling unit that cools the second surface by absorbing heat using the thermoelectric material .

  According to the present invention, there is an effect that electric power can be generated more efficiently using a thermoelectric conversion element.

FIG. 1 is a block diagram schematically showing a configuration of an example of a multifunction machine 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of an example of a thermoelectric conversion module. FIG. 3 is a block diagram illustrating an exemplary configuration of the power generation unit. FIG. 4 is a schematic diagram showing in more detail the configuration of an example of the power generation unit according to the embodiment of the present invention. FIG. 5 is a schematic diagram showing in more detail the configuration of an example of a power generation unit according to a modification of the embodiment of the present invention.

  Hereinafter, embodiments of a power supply device and a power supply unit according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 schematically shows an example of the configuration of an MFP (Multi Function Printer) 1 according to the present embodiment. The MFP 1 realizes a plurality of functions such as a scanner function, a printer function, and a copying function in a single casing. In the example of FIG. 1, the MFP 1 includes a first power supply unit 20, a power supply switching unit 21, a second power supply unit 10, and an image processing unit 30.

  The first power supply unit 20 generates and outputs a power supply used inside the MFP 1 from a commercial power supply. The output of the first power supply unit 20 is supplied to the power supply switching unit 21. The power supply switching unit 21 selects one of the power supplied from the first power supply unit 20 and the power supplied from the second power supply unit 10 to be described later according to the control of the controller 31, and supplies the selected image to the image processing unit 30. To do.

  The image processing unit 30 is a part that performs processing related to the image of the MFP 1, and includes a controller 31, a printer unit 32, a scanner unit 33, and an operation unit 34. The controller 31 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and operates as a work memory according to a program stored in the ROM in advance. To control. The controller 31 also performs image processing in the image processing unit 30.

  The scanner unit 33 reads a document and outputs image data based on the document image. The printer unit 32 performs a printing operation on a sheet or the like according to image data read by the scanner unit 33 or image data supplied from the outside such as a host computer. For example, the image data output from the scanner unit 33 is supplied to the controller 31 and subjected to predetermined image processing. Similarly, image data supplied from the outside is supplied to the controller 31 and subjected to predetermined image processing. The printer unit 32 forms an image on a sheet according to these image data subjected to image processing by the controller 31 and performs printing processing.

  The operation unit 34 includes an operator for performing a user operation, a display unit, and the like, and outputs a control signal corresponding to the user operation to the controller 31. The user can instruct the MFP 1 to operate by operating the operation unit 34.

  Second power supply unit 10 includes a power generation unit 11, a charge / discharge control unit 12, and a storage battery 13. The power generation unit 11 performs power generation using a thermoelectric conversion element. The storage battery 13 charges electricity, and discharges and outputs the charged electricity. The charge / discharge control unit 12 controls charging and discharging of the storage battery 13.

  Further, the charge / discharge control unit 12 controls the output path of the power generation unit 11 and the input / output path of the storage battery 13. As a first example, the charge / discharge control unit 12 connects the power generation unit 11 and the power source switching unit 21 and supplies the power generation output of the power generation unit 11 to the power source switching unit 21. As a second example, the charge / discharge control unit 12 connects the storage battery 13 and the power supply switching unit 21, and supplies the discharge output of the storage battery 13 to the power supply switching unit 21. As a third example, the charge / discharge control unit 12 connects the power generation unit 11 and the storage battery 13 and controls the storage battery 13 to be charged with the power generation output of the power generation unit 11. As a fourth example, the charge / discharge control unit 12 connects the storage battery 13 and the power supply switching unit 21 and controls the storage battery 13 to be charged with the power supplied from the first power supply unit 20.

  Furthermore, the charge / discharge control unit 12 controls the discharge output of the storage battery 13 and the power generation output of the power generation unit 11 to a predetermined voltage and supplies the power supply switching unit 21, for example.

  Note that, for example, when the operation mode of the MFP 1 is a standby mode in which power consumption is suppressed compared to the normal mode, the power supply switching unit 21 is a part to be operated in the standby mode among the units of the image processing unit 30. It is possible to perform control to supply power only and stop supplying power to unnecessary portions. At this time, the power supply source is further switched from the first power supply unit 20 to the second power supply unit 10 to further reduce the power consumption of the commercial power supply.

  Further, the switching of these paths by the charge / discharge control unit 12 depends on, for example, whether the operation mode of the MFP 1 is the standby mode, the magnitude of the discharge output of the storage battery 13, the magnitude of the power generation output of the power generation unit 11, etc. It is possible to control based on this.

  In the above description, the second power supply unit 10 has been described as being incorporated in the MFP 1, but this is not limited to this example. For example, the second power supply unit 10 is configured to be detachable from the MFP 1, the second power supply unit 10 and the power supply switching unit 21 are connected by a cable, and the second power supply unit 10 is an installation location of the MFP 1. It is possible to install in different places. By doing so, even if any of the power generation unit 11, the charge / discharge control unit 12 and the storage battery 13 in the second power supply unit 10 fails, maintenance can be easily performed, and the maintenance cost of the MFP 1 can be reduced. Can be suppressed.

(Power generation method applied to the embodiment)
Next, the power generation method in the power generation unit 11 according to the present embodiment will be described. The power generation unit 11 generates a voltage using a thermoelectric conversion technique. Thermoelectric conversion technology uses the Seebeck effect, in which an electromotive force is generated when two different metals or semiconductors are joined together and a temperature difference is generated between the two ends, and a phenomenon in which the temperature difference of an object is directly converted into a voltage. It is the technology used.

When one end of a thermoelectric conversion element in which two different types of metals or semiconductors are joined is heated, a temperature difference is generated between one and the other end, and electrons move to the lower temperature side. Due to this phenomenon, the balance of the electron density is lost and a potential difference V is generated, and a current flows so as to compensate for it. This potential difference V is expressed by the following formula (1) using the temperature difference ΔT. In addition, coefficient (alpha) in Formula (1) is a Seebeck coefficient, Comprising: It is a coefficient depending on the absolute temperature, material, and molecular structure of a thermoelectric conversion element.
V = α · ΔT (1)

  As can be seen from the equation (1), as the temperature difference ΔT between both ends of the thermoelectric conversion element increases, the potential difference V increases and a high voltage is obtained. A plurality of such thermoelectric conversion elements are laid and connected to form a thermoelectric conversion module. When one surface of the thermoelectric conversion module is heated and the other surface is cooled, a temperature difference ΔT is generated, a potential difference V is generated, and electric power is generated.

  FIG. 2 shows an exemplary configuration of the thermoelectric conversion module 100. In the example of FIG. 2, a p-type thermoelectric conversion material using a p-type semiconductor and an n-type thermoelectric conversion material using an n-type semiconductor are used as the thermoelectric conversion elements. In the thermoelectric conversion module 100, a plurality of sets in which the p-type thermoelectric conversion material and the n-type thermoelectric conversion material are connected in series are further connected in series, and the temperature difference ΔT is arranged in parallel with a certain direction. Thus, a higher voltage can be obtained by further connecting a plurality of sets in which a p-type thermoelectric conversion material and an n-type thermoelectric conversion material are connected in series.

  A pair of the p-type thermoelectric conversion material and the n-type thermoelectric conversion material arranged as described above is sandwiched between the ceramic substrates 111a and 111b. For example, by applying heat energy to the ceramic substrate 111a side and heating it, a temperature difference ΔT is generated between both ends of the p-type thermoelectric conversion material and the n-type thermoelectric conversion material. Electric power due to the potential difference V generated by the temperature difference ΔT is taken out from the output ends 110a and 110b.

  Here, by cooling the back side of the surface to which the thermal energy is applied, that is, the ceramic substrate 111b side, the temperature difference ΔT can be further increased, and more electric power can be taken out.

  FIG. 3 shows an exemplary configuration of the power generation unit 11. The power generation unit 11 includes a thermoelectric conversion module 100, a heating unit 101, and a cooling unit 102. In addition, the arrow in FIG. 3 has shown the flow of heat. The heating unit 101 applies thermal energy to one surface of the thermoelectric conversion module 100. The cooling unit 102 cools the other surface of the thermoelectric conversion module 100.

  In general, the size of the thermoelectric conversion module 100 is, for example, about several centimeters to several tens of centimeters, and the thermoelectric conversion module 100 having the same size can also be used in this embodiment. Further, the thermoelectric conversion module 100 is not limited to being used alone, and a plurality of thermoelectric conversion modules 100 may be used in series connection or parallel connection. The size and number of the thermoelectric conversion modules 100 can be appropriately determined based on the cost, the required amount of power, and the like.

  FIG. 4 shows the configuration of an example of the power generation unit 11 according to the present embodiment in more detail. As described above, in order to generate the potential difference V in the thermoelectric conversion module 100 and to extract electric power from the output ends 110a and 110b, both ends of the thermoelectric conversion module 100, that is, the surfaces of the ceramic substrate 111a shown in FIG. 1) and a surface of the ceramic substrate 111b (referred to as a second surface) needs to generate a temperature difference ΔT.

  In the present embodiment, the heating unit 101 condenses the sunlight 220 with the lens 200 and irradiates the first surface of the thermoelectric conversion module 100 to heat the first surface, and the high temperature side in the temperature difference ΔT is heated. Generate.

  At this time, it is preferable that a driving unit capable of automatically controlling the direction of the lens 200 is provided in the heating unit 101 and the lens 200 is driven so as to change the direction of the lens 200 following the direction of the sun during the daytime. By carrying out like this, it becomes possible to heat the 1st surface of the thermoelectric conversion module 100 more efficiently, and the conversion efficiency of the thermoelectric conversion module 100 can be improved. At this time, it is more preferable to apply a material having high thermal conductivity such as a copper plate to the first surface of the thermoelectric conversion module 100 so that the first surface is uniformly heated.

  For example, it is conceivable to drive the lens 200 in the direction in which the light amount becomes the maximum value using a light amount detection sensor used in a camera or the like. The driving unit that drives the lens 200 is configured by using a stepping motor, and a commercial power source can be used as a driving power source. Not only this but the drive power supply of a drive part may be supplied with a battery.

  The configuration of the cooling unit 102 will be described. The cooling unit 102 uses the thermoelectric material having the Thomson effect as an endothermic material to absorb heat from the second surface of the thermoelectric conversion module 100, thereby cooling the second surface and generating a low temperature side in the temperature difference ΔT.

  Here, an outline of the Thomson effect will be described. The Thomson effect is an effect of absorbing or radiating heat when a current is passed between two points having a temperature difference on one metal, and is one of thermoelectric effects. When an electric current is passed through a substance to which a temperature gradient has been applied, heat generation or endotherm proportional to the amount of electric current flowing occurs.

  The Thomson effect has different characteristics as follows depending on the type of metal used. Zinc and copper are metals that have a hot end at a higher potential and a cold end at a lower potential. When current flows from a hot end to a cold end, energy is released and heat is released. Further, when the current flows from the cold end toward the hot end, energy is absorbed and heat is absorbed. On the other hand, cobalt, nickel, and iron are metals that have a cold end at a higher potential and a hot end at a lower potential. When current flows from a hot end toward a cold end, energy is absorbed and heat is absorbed. . Also, when the current flows from the cold end to the hot end, the energy is released and the heat is dissipated.

  Referring to FIG. 4, the cooling unit 102 includes a heat absorbing material 210, a current source 211, and an optical system 212. The endothermic material 210 is a metal having a Thomson effect, and in this embodiment, a metal such as the above-described zinc or copper, which has a hot end at a higher potential and a cold end at a lower potential, is used. With respect to the heat absorbing material 210, an electric current is supplied from the cold end to the hot end by the current source 211 to obtain an endothermic effect.

  More specifically, one surface (referred to as a third surface) of the endothermic material 210 is brought into close contact with the ceramic substrate 111b, which is the second surface of the thermoelectric conversion module 100, and the other surface of the endothermic material 210 (fourth surface). The surface). As a result, in the endothermic material 210, the temperature of the fourth surface becomes higher than the temperature of the third surface, the fourth surface becomes the hot end, the third surface becomes the cold end, A temperature gradient is generated between the four surfaces. Then, a current is supplied from the third surface to the fourth surface of the heat absorbing material 210 by the current source 211. Thereby, heat absorption by the Thomson effect is generated in the heat absorbing material 210, and the second surface side of the thermoelectric conversion module 100 is cooled.

  Note that a battery may be used as the current source 211. Not limited to this, a commercial power source may be used as the current source 211.

  In the present embodiment, the fourth surface of the endothermic material 210 is heated using sunlight 220. The fourth surface of the endothermic material 210 is irradiated with sunlight 220 through the optical system 212 to heat the fourth surface. For example, when the power generation unit 11 is arranged so that the first surface of the thermoelectric conversion module 100 faces the sun, the optical system 212 is provided with a mirror to reflect the sunlight 220 in the direction of the fourth surface. The optical system 212 is further provided with a lens to collect the sunlight 220 reflected by the mirror and irradiate the fourth surface of the heat-absorbing material 210, thereby increasing the heating efficiency and increasing the temperature gradient in the heat-absorbing material 210. can do.

  Similarly to the case of the heating unit 101 described above, the optical system 212 is also provided with a drive unit that can automatically control the direction, and the direction of the optical system 212 follows the direction of the incident sunlight 220 during the daytime. Then, it is preferable to drive to change. By doing so, the fourth surface of the endothermic material 210 can be heated more efficiently. Thereby, the endothermic effect by the endothermic material 210 can be enhanced, the second surface of the thermoelectric conversion module 100 can be cooled more efficiently, and the conversion efficiency of the thermoelectric conversion module 100 can be improved.

  Thus, according to the present embodiment, when power is generated using the thermoelectric conversion module 100, one surface is heated using sunlight 220, and the other surface is endothermic using the Thomson effect. The material 210 is used for cooling. Therefore, the conversion efficiency by the thermoelectric conversion module 100 is improved, and larger electric power can be obtained.

  Moreover, since the heating for generating a temperature gradient in the endothermic material 210 using the Thomson effect is performed using the sunlight 220, the power consumed for the heating can be suppressed.

(Modification of the embodiment)
Next, a modification of this embodiment will be described. FIG. 5 shows an example of the configuration of the power generation unit 11 ′ according to this modification. In FIG. 5, the same reference numerals are given to the same parts as those in FIG. 4 described above, and detailed description thereof is omitted.

  In the embodiment described above, the first surface of the thermoelectric conversion module 100 is heated using one lens 200 in the heating unit 101. On the other hand, in this modified example, as shown in FIG. 5, a plurality of lenses 201, 201,... And the first surface of the thermoelectric conversion module 100 is heated.

  By concentrating sunlight 220 with each of the plurality of lenses 201, 201,..., The light collection effect is enhanced, and the first surface of the thermoelectric conversion module 100 can be heated more efficiently. Further, as the number of lenses 201, 201,... Increases, the effect of maintaining a high temperature increases, and as a result, the conversion efficiency in the thermoelectric conversion module 100 can be improved.

  Also in this modified example, as in the above-described embodiment, the lens 201, 201,... In this case, it is conceivable to provide a light amount detection sensor and a driving unit for each of the lenses 201, 201,. Not limited to this, one light quantity detection sensor and drive unit may be applied to the entire lens 201, 201,..., And each lens 201, 201,. And a drive part may be applied.

  As described above, according to the modification of the present embodiment, the heating unit 101 ′ that heats the thermoelectric conversion module 100 is provided with a plurality of lenses 201, 201,..., And the plurality of lenses 201, 201,. The light 220 is condensed and heated. Therefore, the thermoelectric conversion module 100 can be heated more efficiently, and the conversion efficiency in the thermoelectric conversion module 100 can be further increased.

  In the above description, the embodiment of the present invention and the modification of the embodiment have been described as being applied to the MFP 1, but this is not limited to this example. In other words, the embodiment of the present invention and the modified example of the present embodiment are also applicable to other devices having a normal mode as an operation mode and a standby mode with reduced power consumption compared to the normal mode, such as a printing apparatus such as a laser printer. Applicable.

1 MFP
DESCRIPTION OF SYMBOLS 10 2nd power supply part 11 Power generation part 12 Charging / discharging control part 13 Storage battery 20 1st power supply part 21 Power supply switching part 30 Image processing part 31 Controller 32 Printer part 33 Scanner part 34 Operation part 100 Thermoelectric conversion module 101 Heating part 102 Cooling part 200 , 201 lens 210 endothermic material 211 current source 212 optical system 220 sunlight

JP 2005-84127 A

Claims (7)

A thermoelectric conversion element that converts a temperature difference between the first surface and the second surface that are opposite to each other into a voltage;
A first heating unit that heats the first surface using sunlight;
Is in close contact with the second surface, is brought into close contact with the second surface of the thermoelectric material having a Thomson effect for performing heat absorbing or dissipating by passing a current between two points with a temperature difference, the thermoelectric conversion element The thermoelectric material is interposed between the second heating unit that heats the fourth surface on the back side of the third surface of the thermoelectric material using sunlight, and the third surface and the fourth surface. A current supply section for passing a current in a direction of absorbing heat, and a cooling section for cooling the second surface by absorbing heat using the thermoelectric material ,
A power generation device comprising: The first heating unit includes
The power generation apparatus according to claim 1, wherein sunlight is collected using a lens and applied to the first surface of the thermoelectric conversion element. The first heating unit further includes:
The power generation device according to claim 2 , further comprising a lens driving unit that drives the lens to follow the direction of the sun. The second heating unit includes
The power generator according to claim 1 , wherein sunlight is reflected by a mirror to irradiate the fourth surface of the thermoelectric material. The second heating unit further includes:
The power generation device according to claim 4 , further comprising a mirror driving unit that drives the mirror so as to follow the direction of the sun. A power generator according to any one of claims 1 to 5 ,
A power storage unit for charging the storage battery and discharging from the storage battery;
A first path for supplying the power generation output of the power generation apparatus to the outside; a second path for supplying the discharge output of the power storage section to the outside; and a third path for supplying the power generation output of the power generation apparatus to the power storage section. A route switching unit for switching between routes,
The power storage unit
When the path switching unit switches to the third path, the storage battery is charged with the power generation output of the power generation apparatus. A power supply device according to claim 6 ,
An image forming unit that forms an image based on the image data;
A power supply switching unit that switches a power supply source to be supplied to the image forming unit between the power supply device and a commercial power supply;
The power switching unit is
When the operation mode of the image forming unit is a standby mode, the power supply source is switched to the power supply device.

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