JP5359090B2 - Power supply device, power supply device for scanner, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To preferably charge a charging section with a power generation section where an output current value is limited. <P>SOLUTION: The power supply device 100 that stores charges generated by a photoelectric section 101 includes a capacitor 103 that stores charges generated by the photoelectric section 101, a battery 105 having a capacitance larger than that of the capacitor 103, and a switching circuit that alternately and regularly switches the connection to the photoelectric section 101 of the capacitor 103 and the connection to the battery 105 of the capacitor 103. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

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

  In recent years, there has been a tendency to digitize information, and image processing apparatuses such as printers and facsimiles used for outputting digitized information and scanners used for digitizing documents have become indispensable devices. Such an image processing apparatus is often configured as a multi-function machine that can be used as a printer, a facsimile, a scanner, and a copier by providing an imaging function, an image forming function, a communication function, and the like. One of the requests for such an image processing apparatus is a request for power saving. As an example of an image processing apparatus that meets the demand for power saving, a method of charging a standby power source by receiving light from a scanner light source by a photovoltaic power generation mechanism used for solar power generation or the like has been proposed (for example, see Patent Document 1). ).

JP 2004-88649 A

  In the invention described in Patent Document 1, the power storage means such as a capacitor is charged by the power generated by the photovoltaic generator that has received the scanner light source, and used as a backup power source when the capacity of the power storage means reaches a predetermined voltage. . However, there may be a case where a high current value cannot be secured as the generated current due to the photoelectric conversion efficiency of the photovoltaic generator and the shortage of the amount of irradiation light. In such a case, depending on the capacity of the power storage means, it takes a very long time for charging.

  On the other hand, when the capacity of the power storage means is lowered, it is possible to charge to a predetermined voltage in a short time, but since the charge that can be accumulated is small, the service life as a power supply is short and the performance as a standby power supply is ensured. I can't. Such a problem can occur not only in the photovoltaic power generation by the scanner light source of the image processing apparatus but also in the charging of the capacity by the power generation means having a low outputable current value.

  The present invention has been made in view of the above, and a power supply device, a power supply device for a scanner, and image formation that can be suitably charged when a power storage unit is charged by a power generation unit having a limit in output current value An object is to provide an apparatus.

A power supply device according to the present invention is a power supply device that accumulates charges generated by a photovoltaic power generation device, the first power storage unit that accumulates charges generated by the photovoltaic power generation device, and static electricity of the first power storage unit. A second power storage unit having a capacitance greater than a capacitance, a first connection that is a connection of the first power storage unit to the photovoltaic device, and the second power storage unit of the first power storage unit. and a second connection is a connection to the power storage unit, and a connection switching unit that switches alternately, said connection switching unit periodically switching Rukoto and said second connection and said first connection It is characterized by.

A scanner power supply apparatus according to the present invention is a scanner that supplies power to a scanner that generates image information by optically scanning the document when a scanner head including a light source moves relative to the document. a use power supply device, and a moving unit which moves in accordance with the scanner head, and a main body portion provided in the scanner body, the moving part, the photovoltaic generating electric charges by receiving light of the light source Unit, a first power storage unit that accumulates the charge generated by the photovoltaic unit, a first connection terminal that electrically connects the moving unit to the main body unit, and the light of the first power storage unit and connection to the power generation portion, and a connection to the first of the first connection terminal of the power storage unit, a connection switching exchange unit that switches alternately wherein the body portion, the first connection terminal The main body part through the moving part A second connection terminal that is electrically connected; and a second power storage unit that receives charges accumulated in the first storage unit via the first connection terminal and the second connection terminal. The first connection terminal and the second connection terminal are connected when the scanner head is in a predetermined arrangement state with respect to the scanner body, and the connection switching unit is connected to the first connection terminal. When the terminal and the second connection terminal are connected, the first power storage unit and the first connection terminal are connected.

An image forming apparatus according to the present invention includes a scanner that optically scans the original by moving a scanner head including a light source relative to the original to generate image information, and supplies power to the scanner. The power supply device includes a moving unit that moves according to the scanner head, and a main body unit provided in the scanner main body, and the moving unit receives light from the light source. A photovoltaic unit that generates electric charge; a first power storage unit that accumulates electric charge generated by the photovoltaic unit; a first connection terminal that electrically connects the moving unit to the main body; and the first A connection switching unit that alternately switches connection of the power storage unit to the photovoltaic unit and connection of the first power storage unit to the first connection terminal, and the main body unit includes the first power storage unit. 1 book through the connection terminal A second connection terminal that electrically connects a part to the moving part, and a second connection terminal that receives charge accumulated in the first storage part via the first connection terminal and the second connection terminal. A power storage unit, and the first connection terminal and the second connection terminal are connected when the scanner head is in a predetermined arrangement state with respect to the scanner body, and the connection switching unit is The first power storage unit and the first connection terminal are connected when the first connection terminal and the second connection terminal are connected.

  Advantageous Effects of Invention According to the present invention, there is an effect that it is possible to suitably perform charging when a power storage unit is charged by a power generation unit having a limit in output current value.

  Exemplary embodiments of a power supply device, a scanner power supply device, and an image forming apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings. A power supply apparatus according to the embodiment described below supplies power to a scanner that reads a document image. The power supply apparatus according to the embodiment shown below includes an image having a scanner unit such as a multi-function machine in which a copying function, a facsimile function, and a scanner function are included in one casing in addition to a copying machine, a facsimile apparatus, a scanner apparatus, and the like. The present invention is applicable to any apparatus that supplies power to the scanner unit of the forming apparatus.

(Embodiment 1)
FIG. 1 is a block diagram schematically showing a circuit configuration of the power supply device 100 according to the first embodiment. As shown in FIG. 1, the power supply device 100 according to the present embodiment includes a photovoltaic power generation unit 101, a switch circuit 102, a capacitor 103, a constant current / constant voltage circuit 104, a battery 105, and terminals 107a and 107b. The photovoltaic power generation unit 101 is a power generation device that converts light energy into electric power by a photoelectric conversion function, and is typically configured by a solar cell or the like. The capacitor 103 serves as a power storage unit that temporarily stores the power generated by the photovoltaic power generation unit 101. The constant current / constant voltage circuit 104 controls the current flowing from the capacitor 103 to the battery 105 to a constant current, or controls the voltage related to the battery 105 to a constant voltage. Constant current and constant voltage circuit 104 may exchange off control of constant current and constant voltage according to the voltage of the battery 105.

  The battery 105 is a power storage unit that stores electric charges stored in the capacitor 103. The battery 105 is a part that finally stores electric charges in the power supply device 100 of the present embodiment. That is, when the power supply device 100 according to the present embodiment is used as a standby power supply or the like, the charge accumulated in the battery 105 is used. The switch circuit 102 has a power generation side terminal 102a and a power storage side terminal 102b, and connects the capacitor 103 to one of them. When the power generation side terminal 102 a is selected, the capacitor 103 is connected to the photovoltaic power generation unit 101, and the generated power of the photovoltaic power generation unit 101 is stored in the capacitor 103. On the other hand, when the power storage side terminal 102 b is selected, the capacitor 103 is connected to the constant current / constant voltage circuit 104 and the battery 105, and electrification stored in the capacitor 103 is transferred to the battery 105. Terminals 107a and 107b are terminals for supplying power stored in the battery 105 to a device to be supplied with power.

The output characteristics of the photovoltaic unit 101 are shown in FIG. FIG. 2 is a graph showing the output characteristics of the photovoltaic unit 101 when the photovoltaic unit 101 is connected to a prescribed load and irradiated with a prescribed amount of light. In FIG. 2, the vertical axis represents the current flowing from the photovoltaic unit 101 to the load, and the horizontal axis represents the output voltage of the photovoltaic unit 101. The current I _SC is a current that flows from the photovoltaic unit 101 to the load when the output is short-circuited, and the voltage V _OC is the output voltage of the photovoltaic unit 101 when the output is open. When the switch circuit 102 selects the power generation side terminal 102a and the photovoltaic unit 101 starts charging the capacitor 103 from a state where no charge is accumulated in the capacitor 103, the output current of the photovoltaic unit 101 starts from I _SC . The output voltage increases and the output current decreases according to the charge accumulated in the capacitor 103. When the voltage V _OC is reached, a steady state is reached.

The output (electric power) of the photovoltaic unit 101 is indicated by the product of the current value and the voltage value on the graph shown in FIG. That is, the point P _MAX where the area of the rectangle having the origin of the graph and the point on the graph as a diagonal is maximum is the maximum output point of the photovoltaic unit 101. The current value at the maximum output point P _{MAX according} to the present embodiment is I _SPM and the voltage value is V _OPM .

FIGS. 3A and 3B are diagrams illustrating current and voltage with time when the photovoltaic unit 101 charges the capacitor 103 in the power supply device 100 according to the present embodiment. FIG. 3A shows the output current value of the photovoltaic unit 101 with respect to the passage of time after the photovoltaic unit 101 starts charging the capacitor 103. 3-2 shows the output voltage of the photovoltaic unit 101 with respect to the passage of time after the photovoltaic unit 101 starts charging the capacitor 103, that is, the charging voltage of the capacitor 103. FIG. FIGS. 3A and 3B show graphs when the capacitance of the capacitor 103 is C ₁ , C ₂ , and C ₃ , respectively. Here, the relationship between C ₁ , C ₂ , and C ₃ is C ₁ <C ₂ <C ₃ . In addition, t ₁ , t ₂ , and t ₃ indicate the time required to complete the charging of the capacitor 103 when the capacitances are C ₁ , C ₂ , and C ₃ . The relationship between t ₁ , t ₂ , and t ₃ is t ₁ <t ₂ <t ₃ .

As shown in FIGS. 3A and 3B, the larger the capacitance of the capacitor 103, the longer the time required for completion of charging. This time is mainly determined by the internal impedance of the photovoltaic unit 101 and the time constant of the capacitor 103. That is, if the capacitance of the capacitor 103 is large, it is possible to store a larger amount of charge, but the time required for charging to a desired voltage is also increased. On the other hand, if the electrostatic capacity is lowered, it is possible to charge to a desired voltage in a short time, but the amount of charge that can be accumulated decreases. Further, if the value of the current I _{SC that} can be output from the photovoltaic unit 101 is low, it takes a long time to complete the charging of the capacitor 103.

  Next, with reference to FIG. 4, the charging characteristics of battery 105 of power supply device 100 according to the present embodiment will be described. In FIG. 4, the horizontal axis indicates the elapsed time from the start of charging of the battery 105, and the vertical axis indicates the charging current and charging capacity of the battery 105. FIG. 4 shows four graphs a to d. Of these graphs, examples according to the present embodiment are a and b. a is a graph showing changes in charging current in time series when the battery 105 is charged via the constant current / constant voltage circuit 104; Moreover, b is a graph which shows the change of the charging capacity in time series when the battery 105 is charged by the aspect of a.

In the present embodiment, charging of the battery 105 is controlled by a constant current / constant voltage circuit 104. The constant current / constant voltage circuit 104 charges the battery 105 with a constant current at the beginning of charging of the battery 105. At this time, the current value at which the constant current / constant voltage circuit 104 charges the battery 105 is defined as 1 C current. The 1C current is a current value determined based on the charging capacity of the battery 105 and is a current value allowed for charging the battery 105. That is, the constant current / constant voltage circuit 104 plays a role of limiting the current that flows when the battery 105 is charged. Constant current and constant voltage circuit 104 monitors the terminal voltage of the battery 105, at a timing t _v shown in FIG. 4, the charge voltage of the battery 105 reaches a predetermined value, replacement cut from the constant current charging to constant voltage charging Yeah. In this case, the constant current / constant voltage circuit 104 limits the battery 105 from being charged beyond a predetermined voltage, that is, the rated capacity. Then, at the timing t _f shown in FIG. 4, the charging capacity of the battery 105 reaches the rated capacity, and charging is completed.

On the other hand, graphs c and d shown in FIG. 4 are graphs showing comparative examples of the present embodiment. c is a graph showing changes in charging current in time series when the photovoltaic unit 101 directly charges the battery 105. Further, d is a graph showing the change in charge capacity in time series when the battery 105 is charged according to the mode of c. As described above, the output current of the photovoltaic unit 101, where I _SC is a maximum value of the current I _SC is lower than the value of 1C current common charging batteries. Therefore, as shown in the graph d of FIG. 4, when the battery 105 is directly charged by the photovoltaic unit 101, it takes a very long time to charge the battery 105 to the rated capacity. The gist of the present embodiment is that the capacitor 103 is provided between the photovoltaic unit 101 and the battery 105, and the capacity of the capacitor 103 is adjusted, whereby the photovoltaic unit 101 is suitably charged by the photovoltaic unit 101. .

Next, a charging operation of power supply device 100 according to the present embodiment will be described. FIG. 5 is a graph and timing chart showing the charging operation of the battery 105 of the power supply apparatus 100 according to the present embodiment. The graph shown in FIG. 5 is a graph showing changes in charging current and charging capacity of the battery 105 in time series in the power supply device 100 according to the present embodiment. In addition, the timing chart illustrated in FIG. 5 indicates which of the power generation side terminal 102a and the power storage side terminal 102b is selected by the switch circuit 102 on the time axis common to the graph illustrated in FIG. In the period T _{1 to} T ₉ shown in FIG. 5, it is assumed that a predetermined amount of light is always applied to the photovoltaic unit 101.

  In the present embodiment, the switch circuit 102 includes a connection of the selection terminal to the power generation side terminal 102a (that is, connection of the capacitor 103 to the photovoltaic unit 101) and a connection of the selection terminal to the power storage side terminal 102b (that is, the connection). The connection of the capacitor 103 to the battery 105) is alternately and periodically switched.

That is, in the period T ₁ shown in FIG. 5, the switch circuit 102 selects the power generation side terminal 102a. Accordingly, the capacitor 103 is charged by the power generated by the photovoltaic unit 101. Here, as described with reference to FIGS. 3A and 3B, the time required for charging the capacitor 103 varies depending on the capacitance of the capacitor 103. If the time required to charge up to V _OC when the capacitor 103 is charged by the photovoltaic unit 101 is T _VOC , the periods T ₁ , T ₃ , T ₅ , and T ₇ are longer than T _VOC . That is, when the photovoltaic power generation unit 101 charges the capacitor 103, the capacitance of the capacitor 103 is set so that the charging is completed within the periods T ₁ , T ₃ , T ₅ , and T ₇ .

Next, transition from the period T ₁ to T ₂ and when the switch circuit 102 selects the power storage side terminal 102 b, the capacitor 103 is connected to the battery 105 via the constant current / constant voltage circuit 104. Thereby, the electric charge accumulated in the capacitor 103 moves to the battery 105, and the battery 105 is charged. The capacitor 103 is not limited to an output current of I _SC unlike the photovoltaic unit 101, and a current flows according to the stored voltage. Therefore, it is possible to charge the battery 105 with higher efficiency than the modes of the graphs c and d shown in FIG. In the charging of the battery 105 due to the capacitor 103, the charging current is limited to 1C current, as shown in the period T ₂ of the FIG. 5 by the function of the constant current and constant voltage circuit 104.

As shown in FIG. 5, the charge accumulated in the capacitor 103 moves to the battery 105 and the voltage of the capacitor 103 decreases. When the voltage of the capacitor 103 and the voltage of the battery 105 become close, the charging current decreases. That is, the decrease in the charging current in the period T ₂ in FIG. 5 is not due to the function of the constant current / constant voltage circuit 104 but is due to the charge of the capacitor 103 being used up. In addition, the period T ₂ is longer than the period until the electric current starts to move from the capacitor 103 to the discharged battery 105 and no current flows from the capacitor 103 to the battery 105 when the voltage of the capacitor 103 decreases. It is preferable. In addition, the length of the period T ₂ may be longer than the period until the current flowing from the capacitor 103 to the battery 105 becomes lower than a predetermined value. The predetermined current value is, for example, a 1C current of the battery 105.

Next, when the period transitions from T ₂ to T ₃ and the switch circuit 102 selects the power generation side terminal 102a, the capacitor 103 and the photovoltaic unit 101 are connected again, and the photovoltaic unit 101 generates power as in the period T _1. The capacitor 103 is charged by the electric power. Next, the period transitions from T ₃ to T ₄ , the switch circuit 102 selects the power storage side terminal 102 b, and the battery 105 is charged by the charge accumulated in the capacitor 103. As shown in FIG. 5, in the period T ₄ , charging is performed so as to be added to the charging capacity charged in the period T ₂ . Also in the period T _4, the voltage of the battery 105 does not reach the cut exchange e threshold between constant-current charging and constant voltage charging is set to the constant current and constant voltage circuit 104, the voltage drop of the capacitor 103 The charging current decreases.

When transitioning from the period T ₄ to the period T ₅ , the capacitor 103 is charged by the generated power of the photovoltaic unit 101 as in the periods T ₁ and T ₃ . When transitioning from the period T ₅ to the period T ₆ , the battery 105 is charged by the charge accumulated in the capacitor 103 as in the periods T ₂ and T ₄ . In the period T ₆ , charging is performed so as to be added to the charging capacity charged in the period T ₄ . In the period T ₆ reaches the cut-exchange e threshold charging voltage and constant current charging and constant voltage charging is set to the constant current and constant voltage circuit 104 of the battery 105, the charging of the constant current and constant voltage circuit 104 is a battery 105 the can exchange cut from the constant current charging to constant voltage charging. That is, reduction of the charging current in the period T _6, by the function of the constant-current and constant-voltage circuit 104, due to being gills replacement cut from the constant current charging to constant voltage charging. Even during the period T ₆ , the charging capacity of the battery 105 does not reach the rated capacity, and the charging current becomes zero due to the voltage drop of the capacitor 103.

When transitioning from the period T ₆ to the period T ₇ , the capacitor 103 is charged by the generated power of the photovoltaic unit 101 as in the periods T ₁ , T ₃ , and T ₅ . When transitioning from the period T ₇ to the period T ₈ , the battery 105 is charged by the electric charge accumulated in the capacitor 103 as in the periods T ₂ , T ₄ , and T ₆ . In the period T ₈ , charging is performed so as to be added to the charging capacity charged in the period T ₆ . Further, in the period T _8, since the period T ₆ the voltage of the battery 105 reaches a cut replacement example threshold of constant current and constant voltage circuit 104, as shown in FIG. 5, a low voltage charging from the beginning. That is, the charging current is lower than the 1C current at the start of the period T ₈ , and the charging current decreases as the charging voltage of the battery 105 increases. In period T ₈ , the charging capacity of the battery 105 reaches the rated capacity, and the charging of the battery 105 is completed.

As described above, in the power supply device 100 according to the present embodiment, by setting the capacitance of the capacitor 103 charged by the photovoltaic unit 101 to be lower than that of the battery 105, the maximum output current I _SC is low. Even so, the capacitor 103 is quickly charged to a predetermined voltage value (V _OC in the above embodiment). Further, by transferring the charge accumulated in the capacitor 103 to a battery having a large capacity, a large capacity can be charged. Thereby, it is possible to suitably perform charging when the power storage means is charged by the power generation means having a limit in the output current value. As an example of the effect according to the present embodiment, for example, when charging the battery 105, it is essential to use the constant current / low voltage circuit 104 to charge with a current of 1 C or a current close thereto at the beginning of charging. Cases. When the battery 105 is directly charged by the photovoltaic unit 101, the charging current is limited to I _SC as described above. As described above, when the current I _SC is lower than the 1C current, the battery 105 cannot be charged. However, by using the aspect according to the present embodiment, the battery 105 is not limited to the I _SC. It is possible to pass a current through

  Next, an application example of the power supply device 100 according to the present embodiment will be described. FIG. 6 shows an example in which the power supply apparatus 100 according to the present embodiment is applied to a scanner 200 that optically scans a document and generates image information. In the scanner 200, a document placed on the contact glass 201 is exposed by a light source 202, and reflected light is guided to a photoelectric conversion unit 204 by a mirror 203, thereby generating image information of the document. The photovoltaic unit 101 of the power supply apparatus 100 is arranged so that the light emitted from the light source 202 can be received with respect to such a scanner 200. In this manner, when the scanner 200 operates and the light source 202 emits light, the photovoltaic unit 101 receives light from the light source 202 and generates electric power. By using the power of the battery 105 of the power supply apparatus 100 charged by the operation of the scanner 200 as a standby power supply during the power saving operation of the image processing apparatus including the scanner 200, the usage amount of the commercial power supply is reduced and the power consumption is reduced. Electricity can be achieved.

As a modification 1 of the first embodiment, for example replacement cut at the selection terminal of the switch circuit 102, for example, it can be performed based on the voltage of the capacitor 103. FIG. 7 is a circuit configuration diagram of a power supply device according to Modification 1 of Embodiment 1. The power supply device 700 is provided with a voltage detection circuit 701 that detects the voltage value of the capacitor 103 in addition to the configuration of the power supply device 100 of the first embodiment, and other configurations are the same as those of the first embodiment. .

In the first modification, the voltage value of the capacitor 103 is detected by the voltage detection circuit 701 in a state where the switch circuit 102 selects the power generation side terminal 102a, and when the detected voltage value reaches a predetermined voltage, the storage side terminal e replacement cut into 102b, transferring the charges accumulated in the capacitor 103 to the battery 105. Thus, charging of the capacitor 103 is completed by the photovoltaic unit 101 shortens the state of waiting for example replacement off of the switch circuit 102, it is possible to improve the charging efficiency of the battery 105.

Further, as a second modification of the first embodiment, based on the photovoltaic unit 101 to the value of the current flowing through the capacitor 103 can also be may exchange off selection terminal of the switch circuit 102. FIG. 8 is a circuit configuration diagram of the power supply device according to the second modification of the first embodiment. This power supply device 800 is provided with a current detection circuit 801 that detects a current value flowing from the photovoltaic power generation unit 101 to the capacitor 103 in addition to the configuration of the power supply device 100 of the first embodiment. This is the same as the first embodiment.

In the second modification, the current value flowing from the photovoltaic power generation unit 101 to the capacitor 103 is detected by the current detection circuit 801 in a state where the switch circuit 102 selects the power generation side terminal 102a, and the detected current value is a predetermined current value. e cut replacement to the storage terminal 102b at the time of the drop to, transferring the charges accumulated in the capacitor 103 to the battery 105. Thus, charging of the capacitor 103 is completed by the photovoltaic unit 101 shortens the state of waiting for example replacement off of the switch circuit 102, it is possible to improve the charging efficiency of the battery 105.

  In the first embodiment, the example in which the battery 105 is used as the power storage unit that eventually accumulates electric charges has been described. However, the power storage unit is not limited thereto. In the third modification of the first embodiment, for example, a capacitor is used as a power storage unit that finally accumulates electric charges. FIG. 9 is a circuit configuration diagram of a power supply device 900 according to the third modification of the first embodiment. The power supply device 900 includes a capacitor 106 as a power storage unit that finally accumulates electric charges, and other configurations are the same as those in the first embodiment.

  In this case, a capacitor having a larger capacitance than the capacitor 103 is used as the capacitor 106. When the battery 105 is used as the power storage unit, the constant current / constant voltage circuit 104 needs to be used to control the 1C current. However, when the capacitor 106 is used, it is not necessary to control the 1C current, and the constant current / constant voltage is used. Since the circuit 104 can be omitted, productivity can be improved. In addition, since the charging current is not limited to the 1C current, it is possible to transfer charges from the capacitor 103 with higher efficiency. On the other hand, since the voltage of the capacitor 106 drops according to the discharge of the accumulated electric charge, the stability of power supply is impaired. Therefore, it is preferable to appropriately use the battery 105 and the capacitor 106 according to the use of the power supply device 100 and the like.

(Embodiment 2)
In the first embodiment, it has been described El example exchange disconnects the capacitor 103 and the photovoltaic unit 101 or the battery 105 by switching circuit 102. In the present embodiment, in the case of using the power supply 100 to the image processing apparatus having a scanner, an example in which devised the connection cutting exchange e operation. In addition, about the structure which attaches | subjects the code | symbol similar to Embodiment 1, the same or equivalent part as Embodiment 1 is shown, and description is abbreviate | omitted.

  First, a configuration of a light source unit of a general scanner 200 will be described with reference to FIG. As described above, in the scanner 200, the document placed on the contact glass 201 is exposed by the light source 202, and the reflected light is guided to the photoelectric conversion unit 204 by the mirror 203, thereby generating image information of the document. Here, the light source 202 and the mirror 203 are configured as a scanner head 205. When executing the scan, the scanner head 205 moves relative to the contact glass 201 to optically scan the entire surface of the document placed on the contact glass 201.

  As shown in FIG. 6 of Embodiment 1, in order to improve the light receiving efficiency from the moving light source 202 and improve the photovoltaic power generation efficiency, the photovoltaic power generation unit 101 is provided over a wide range. However, when the photovoltaic unit 101 having a wide light receiving unit is used, the cost increases and the productivity decreases. On the other hand, the light receiving unit may be fixed to the light source 202, and the light receiving unit may be moved at the same time when the scanner head 205 is moved. However, in order to supply the power stored in the power supply apparatus 100 to the apparatus main body to be supplied with power, it is necessary to connect the power supply unit of the apparatus main body and the power supply apparatus 100.

  For example, let us consider a case in which the photovoltaic unit 101 is provided on the scanner head 205 side and the other configuration is provided on the apparatus main body side in the configuration of the power supply apparatus 100 shown in FIG. In such a case, considering the moving range of the scanner head 205, the wiring connecting the photovoltaic unit 101, the switch circuit 102, and the capacitor 103 needs to have a corresponding length, but the resistance component due to the length of the wiring is taken into consideration. Then, it is necessary to thicken the wiring. However, a thick wiring may undesirably hinder the movement of the scanner head 205 and is not preferable. Further, when a configuration other than the photovoltaic unit 101 is also provided on the scanner head 205 side, the weight of the configuration that moves simultaneously with the scanner head 205 increases, which also becomes a factor that hinders the movement of the scanner head 205. The power supply apparatus 100 according to the present embodiment solves such a problem. In a scanner that optically scans the entire surface of a document by moving the scanner head relative to the document, the scanner head It is possible to suitably perform photovoltaic power generation by the scanner light source without hindering the movement of the scanner.

  11 and 12 are diagrams showing the scanner head 205 and the power supply apparatus 1100 according to the present embodiment. The power supply device 1100 according to the present embodiment includes a moving unit 1100a and a fixed unit 1100b. The moving unit 1100a and the fixed unit 1100b are configured to be separable. FIG. 11 shows a state where the moving unit 1100a and the fixed unit 1100b are separated, and FIG. 12 shows a state where the moving unit 1100a and the fixed unit 1100b are connected. The moving unit 1100a is shown by being surrounded by a dotted line in FIG. 11, and is a portion fixed to the scanner head 205. When the scanner head 205 moves relative to the contact glass, it moves together with the scanner head 205. To do. The fixed part 1100b is a part fixed to the scanner to be supplied with power.

  As illustrated in FIG. 11, the moving unit 1100 a includes a photovoltaic unit 101, a capacitor 111, a switch circuit 112, a connection detection switch 113, a protrusion 114, and a connection terminal 121. The fixed portion 1100 b includes a constant current / constant voltage circuit 104, a battery 105, a switch circuit 115, a protrusion 116, a connection detection switch 117, a capacitor 118, and a connection terminal 122. The capacitor 111 in the moving unit 1100a corresponds to the capacitor 103 in the first embodiment. That is, the capacitor 111 temporarily holds the generated power of the photovoltaic unit 101. Further, the capacitor 118 in the fixed unit 1100b receives the electric charge accumulated in the capacitor 111 and temporarily holds it in a state where the moving unit 1100a and the fixed unit 1100b are connected. In the present embodiment, the battery 105 is charged by the charge accumulated in the capacitor 118 moving to the battery 105.

The switch circuit 112 of the mobile unit 1100a has a power-side terminal 112a and a fixed portion side terminal 112b, may exchange cut and a state in which the capacitor 111 is connected to the connection terminal 121 in the state of being connected to the photovoltaic unit 101. The switch circuit 115 of the fixed portion 1100b has a moving portion side terminal 115a and the power storage-side terminal 115b, obtain replacement cut and a state in which the capacitor 118 is connected to the connected state and the battery 105 to the connection terminals 122 .

Connection detecting switch 113 detects that the mobile unit 1100a and a fixed portion 1100b are connected, it may exchange off selection terminal of the switch circuit 112. The connection detection switch 117 detects that the mobile unit 1100a and a fixed portion 1100b are connected, it may exchange off selection terminal of the switch circuit 115. The connection detection switch 113 and the connection detection switch 117 each have a recess. In a state where the moving unit 1100a and the fixed unit 1100b are connected, the projection 116 of the fixed unit 1100b is inserted into the recess of the connection detection switch 113, and the projection 114 of the movement unit 1100a is inserted into the recess of the connection detection switch 117. . In a state where the protrusion 116 is inserted into the recess of the connection detection switch 113, the connection detection switch 113 controls the switch circuit 112 to select the fixed portion side terminal 112b. Further, in a state where the protrusion 114 is inserted into the recess of the connection detection switch 117, the connection detection switch 117 controls the switch circuit 115 to select the moving unit side terminal 115a.

  When the switch circuit 112 selects the power generation side terminal 112 a, the capacitor 111 is connected to the photovoltaic power generation unit 101, and the generated power of the photovoltaic power generation unit 101 is accumulated in the capacitor 111. In this case, the switch circuit 115 selects the power storage side terminal 115b, and the battery 105 is charged by the electric charge accumulated in the capacitor 118. On the other hand, when the switch circuit 112 selects the fixed portion side terminal 112b, the capacitor 111 is connected to the connection terminal 121, and the charge accumulated in the capacitor 111 moves to the fixed portion 1100b via the connection terminal 121. To do. In this case, the switch circuit 115 selects the moving unit side terminal 115a, and the capacitor 118 is connected to the capacitor 111 via the connection terminal 122. As a result, the charge accumulated in the capacitor 111 moves to the capacitor 118 until the capacitor 111 and the capacitor 118 have the same voltage.

  As described with reference to FIG. 10, the light source 202 is turned on while the scanner head 205 moves relative to the contact glass 201, and the original placed on the contact glass 201 is optically scanned. The moving part 1100a and the fixed part 1100b are separated. Therefore, the switch circuit 112 selects the power generation side terminal 112 a and the generated power of the photovoltaic power generation unit 101 is stored in the capacitor 111. In addition, the switch circuit 115 selects the power storage side terminal 115 b, and the battery 105 is charged by the electric charge accumulated in the capacitor 118.

  When the scanning of the original is completed and the scanner head 205 is in a predetermined arrangement state (home position) with respect to the scanner body, the moving unit 1100a and the fixed unit 1100b are connected. In this case, the switch circuit 112 selects the fixed part side terminal 112b, and the switch circuit 115 selects the moving part side terminal 115a. Therefore, the capacitor 111 and the capacitor 118 are connected via the connection terminals 121 and 122, and the charge accumulated in the capacitor 111 moves to the capacitor 118 until the capacitor 111 and the capacitor 118 have the same voltage.

Here, the voltage of the capacitor 111 is charged to V _OC by the photovoltaic unit 101, but the movement of charge from the capacitor 111 to the capacitor 118 stops when the voltage of the capacitor 118 becomes the same voltage as the capacitor 111. Therefore, the voltage of the capacitor 118 does not exceed V _{OC in} principle. Specifically, when the capacitance of the capacitor 111 and the capacitance of the capacitor 118 are the same, when the half of the electric charge stored in the capacitor 111 moves to the capacitor 118, both become the same voltage. That is, the voltage of the capacitor 118 rises to half the value of V _OC . Further, when the capacitor 111 has a higher capacity than the capacitor 118, both of them have the same voltage when less than half of the charge of the capacitor 111 moves to the capacitor 118. That is, the voltage on capacitor 118 rises to a value higher than half of V _OC . Further, when the capacitor 111 has a lower capacity than the capacitor 118, both of them have the same voltage when more than half of the charge of the capacitor 111 has moved to the capacitor 118. That is, the voltage on capacitor 118 only rises to a value lower than half of V _OC .

Therefore, the capacity of the capacitor 118 and the capacity of the capacitor 111 are preferably adjusted as appropriate according to the V _OC that is the maximum voltage of the photovoltaic unit 101 and the output voltage or rated capacity of the battery 105. For example, if the capacitance of the capacitor 111 is made higher than that of the capacitor 118, the charging voltage of the capacitor 118 can be increased. However, since the charge remaining on the capacitor 111 side is large, the charging efficiency of the battery 105 decreases as a result. . On the other hand, when the capacitance of the capacitor 111 is made lower than that of the capacitor 118, the charge remaining on the capacitor 111 side can be reduced, but the charging voltage of the capacitor 118 is lowered.

  As described above, in the scanner and power supply apparatus 1100 according to the present embodiment, when the scanner is performing a scanning operation, the power generated by the scanner light source is accumulated in the capacitor 111 that moves together with the scanner head 205. During the non-execution of the scanning operation, the electric charge accumulated in the capacitor 111 moves to the capacitor 118 provided on the scanner body side. When the scanner operation is executed again, the battery 105 is charged with the electric charge accumulated in the capacitor 118 and the power generated by the scanner light source is accumulated in the capacitor 111. With such a configuration, it is possible to suitably perform photovoltaic power generation by the scanner light source without mechanically hindering the movement of the scanner head 205.

  In the above description, the example in which the moving unit 1100a and the fixed unit 1100b are connected at the home position where the scanner head 205 is located in a state where the scanning operation is not performed has been described. In addition, the moving unit 1100a and the fixed unit 1100b can be connected at a plurality of positions on the movement locus of the scanner head 205. An example of such a case is shown in FIG. 13 as a modification of the second embodiment. FIG. 13 is a diagram illustrating an example in which connection terminals 122 connected to the connection terminals 121 of the moving unit 1300a are provided at a plurality of positions on the movement trajectory of the scanner head 205. In FIG. 13, the plurality of connection terminals 122 are connection terminals 122a, 122b, and 122c, respectively.

  FIG. 13 shows an arrangement state of the scanner head 205, the moving unit 1300a, and the fixed unit 1300b when the scanning operation is not performed. As shown in FIG. 13, in the power supply device 1300, during the non-scan operation, the connection terminal 121 of the moving unit 1300a is connected to the connection terminal 122a of the fixed unit 1300b. In this state, the switch circuit 112 selects the fixed portion side terminal 112b, and the switch circuit 115 selects the moving portion side terminal 115a. Accordingly, the charge accumulated in the capacitor 111 moves to the capacitor 118. When the scanning operation is started and the scanner head 205 and the moving unit 1300a move along the arrow Q in FIG. 13, the connection between the connection terminal 121 and the connection terminal 122a is released. An example of this state is shown in FIG.

  As shown in FIG. 14, when the scanner head 205 and the moving unit 1300a move and the connection between the connection terminal 121 and the connection terminal 122a is released, the switch circuit 112 selects the power generation side terminal 112a, and the switch circuit 115 The power storage side terminal 115b is selected. Therefore, the power generated by the photovoltaic unit 101 that has received the light from the light source 202 is accumulated in the capacitor 111. Further, the battery 105 is charged by the electric charge accumulated in the capacitor 118.

When the scanner head 205 and the moving unit 1300a further move from the state shown in FIG. 14 in the scanning operation, the connection terminal 121 and the connection terminal 122b are connected as shown in FIG. In this case, the switch circuit 112 selects the fixed part side terminal 112b, and the switch circuit 115 selects the moving part side terminal 115a. Thereby, the charge accumulated in the capacitor 111 after the connection between the connection terminal 121 and the connection terminal 122a is released moves to the capacitor 118. Even in this state, the scanner head 205 and the moving unit 1300a are in a scanning operation and continue to move. Therefore, the period in which the connection terminal 121 and the connection terminal 122b are connected is a very short period. However, as described in the first embodiment, when the charge is transferred from the capacitor 111 to the capacitor 118, the current is not limited to I _SC unlike the photovoltaic unit 101. can do.

  When the scanner head 205 and the moving unit 1300a further move from the state shown in FIG. 15, the connection between the connection terminal 121 and the connection terminal 122b is released. Accordingly, as in FIG. 14, the switch circuit 112 selects the power generation side terminal 112a, and the switch circuit 115 selects the power storage side terminal 115b. Therefore, the power generated by the photovoltaic unit 101 that has received the light from the light source 202 is accumulated in the capacitor 111. Further, the battery 105 is charged by the electric charge accumulated in the capacitor 118. Thereafter, when the scanner head 205 and the moving unit 1300a further move, the connection terminal 121 and the connection terminal 122c are connected. In this case, as in FIG. 15, the switch circuit 112 selects the fixed portion side terminal 112b, and the switch circuit 115 selects the moving portion side terminal 115a. Accordingly, the charge accumulated in the capacitor 111 after the connection between the connection terminal 121 and the connection terminal 122b is released moves to the capacitor 118.

  Further, in order to lengthen the connection period between the connection terminal 121 and the connection terminal 122b, the shapes of the connection terminal 121 and the connection terminal 122b are extended in the relative movement direction of the scanner head 205, the moving unit 1300a, and the fixed unit 1300b. Also good. Such an example will be described with reference to FIGS. 16-1 to 16-5. FIGS. 16-1 to 16-5 are diagrams schematically illustrating the periphery of the connection terminal 121 and the connection terminal 122b in a state where the moving unit 1300a is moving relative to the fixed unit 1300b. 16A is a diagram illustrating a state before the connection terminal 121 is connected to the connection terminal 122b, and corresponds to the state of FIG.

  When the moving unit 1300a further moves from the state illustrated in FIG. 16A and the respective terminals included in the connection terminal 121 and the connection terminal 122b come into contact as illustrated in FIG. 16B, a state corresponding to FIG. Here, as illustrated in FIG. 16B, the shape of each of the terminals included in the connection terminal 121 and the connection terminal 122b is extended in a direction in which the moving unit 1300a moves relative to the fixed unit 1300b. . Therefore, even in the state where the moving unit 1300a is moving relative to the fixed unit 1300b, the respective states shown in FIGS. 16-1 to 16-4 are the same as the states shown in FIG. The capacitor 111 is connected to the capacitor 118. When the moving unit 1300a further moves from the state illustrated in FIG. 16-4, the connection between the connection terminal 121 and the connection terminal 122b is released as illustrated in FIG. 16-5.

For cut replacement example control of the selection terminal of the switch circuit 112 and the switch circuit 115 in the example shown in FIG. 13, for example, the period T _1, T _2, T ₃ described in FIG. 5 of the first embodiment, ... of As such, it can be controlled by time. Here, in the cut-exchange example control of the selection terminal of the switch circuit 112 of this embodiment, the connection terminal 112a of the code 102a of the connecting terminal in Fig. 5, replaced the code 102b of the connecting terminal in Fig. 5 to the connection terminal 112b Apply. In the cut-exchange example control of the selection terminal of the switch circuit 115, the connection terminal 115a of the code 102a of the connecting terminal in Fig. 5, and applied replaced the code 102b of the connecting terminal in Fig. 5 to the connection terminal 115b.

Each of the periods T ₁ , T ₂ , T ₃ ,... Is the time from when the connection between the connection terminal 121 and the connection terminal 122a is released until the connection terminal 121 is connected to the connection terminal 122b. It is determined by the time that the connection terminal 121 is connected to the connection terminal 122b. That is, it is determined based on the speed at which the moving unit 1300a moves relative to the fixed unit 1300b. Further, similarly to the example shown in FIG. 11 and 12, may be e replacement cut by a mechanical switch.

  In the above description, the example in which the capacitor 118 is provided in the fixed portion 1300b, the charge accumulated in the capacitor 111 is moved to the capacitor 118, and then the battery 105 is charged by the charge accumulated in the capacitor 118 has been described. As a result, when moving the charge from the moving unit 1300a side to the fixed unit 1300b side, the charge can be moved quickly without being limited by the 1C current value of the battery 105. However, as described with reference to FIGS. 16A to 16E, the capacitor 118 of the fixed portion 1300b may be omitted if the charge transfer time from the capacitor 111 to the capacitor 118 can be secured. Thereby, the circuit can be simplified. Further, depending on the capacity of the battery 105, the charge remaining in the capacitor 111 can be reduced, and the charging efficiency can be improved.

  In the above description, the example in which the moving unit 1300a is provided integrally with the scanner head 205 has been described. However, the moving unit 1300a may be configured separately from the scanner head 205, and at least the moving unit 1300a can move according to the movement of the scanner head 205 to obtain the same effect as described above.

1 is a circuit configuration diagram of a power supply device according to Embodiment 1. FIG. It is a figure which shows the output characteristic of the photovoltaic power generation part which concerns on Embodiment 1. FIG. It is a figure which shows the charge characteristic of the capacitor | condenser which concerns on Embodiment 1, and shows the output electric current value (current which flows through a capacitor | condenser) of the photovoltaic unit with respect to the time passage after a photovoltaic unit started charging a capacitor | condenser. It is a figure which shows the charge characteristic of the capacitor | condenser which concerns on Embodiment 1, and shows the charging voltage of the capacitor | condenser with respect to time passage after a photovoltaic part started charge of a capacitor | condenser. FIG. 4 is a diagram showing charging characteristics of the battery according to Embodiment 1. FIG. 3 is a diagram illustrating a charging mode of the battery according to the first embodiment. It is a figure which shows typically the circuit structure at the time of applying the power supply device which concerns on Embodiment 1 to a scanner. FIG. 6 is a circuit configuration diagram of a power supply device according to a first modification of the first embodiment. 6 is a circuit configuration diagram of a power supply device according to a second modification of the first embodiment. FIG. FIG. 6 is a circuit configuration diagram of a power supply device according to a third modification of the first embodiment. FIG. 6 is a diagram showing a scanner head and its surroundings according to a second embodiment. It is a circuit block diagram of the scanner head and power supply device which concern on Embodiment 2, and is a figure which shows the state which the moving part and the fixed part isolate | separated. It is a circuit block diagram of the scanner head and power supply device which concern on Embodiment 2, and is a figure which shows the state which the moving part and the fixed part connected. It is a circuit block diagram of the scanner head and power supply device which concern on the modification of Embodiment 2, and is a figure which shows the state where scanning operation | movement is not performed. FIG. 10 is a circuit configuration diagram of a scanner head and a power supply device according to a modification of the second embodiment, and shows a state where connection of connection terminals is released. FIG. 10 is a circuit configuration diagram of a scanner head and a power supply device according to a modification of the second embodiment, and shows a state where connection terminals are connected. In the power supply device which concerns on the modification of Embodiment 2, it is a schematic diagram of the periphery of a connection terminal in the state before a connection terminal is connected. In the power supply device which concerns on the modification of Embodiment 2, it is a schematic diagram of the periphery of a connection terminal in the state in which the connection terminal is connecting. In the power supply device which concerns on the modification of Embodiment 2, it is a schematic diagram of the periphery of a connection terminal in the state in which the connection terminal is connecting. In the power supply device which concerns on the modification of Embodiment 2, it is a schematic diagram of the periphery of a connection terminal in the state in which the connection terminal is connecting. In the power supply device which concerns on the modification of Embodiment 2, it is a schematic diagram of a connection terminal periphery in the state by which the connection of the connection terminal was cancelled | released.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,700,800,900,1100,1300 Power supply device 1100a, 1300a Moving part 1100b, 1300b Fixed part 101 Photoelectric power generation part 102 Switch circuit 102a Power generation side terminal 102b Power storage side terminal 103 Capacitor 104 Constant current / constant voltage circuit 105 Battery 106 Capacitors 107a and 107b Terminal 111 Capacitor 112 Switch circuit 112a Power generation side terminal 112b Fixed part side terminal 113 Connection detection switch 114 Protrusion part 115 Switch circuit 115a Moving part side terminal 115b Power storage side terminal 116 Protrusion part 117 Connection detection switch 118 Capacitors 121 and 122 , 122a, 122b, 122c Connection terminal 200 Scanner 201 Contact glass 202 Light source 203 Mirror 204 Photoelectric converter 205 Scan Nahead

Claims (10)

A power supply device for accumulating charges generated by a photovoltaic device,
A first power storage unit for accumulating charges generated by the photovoltaic device;
A second power storage unit having a capacitance greater than the capacitance of the first power storage unit;
A first connection that is a connection of the first power storage unit to the photovoltaic device and a second connection that is a connection of the first power storage unit to the second power storage unit are alternately switched. A connection switching unit;
Equipped with a,
The connection switching portion, the first connection and the second connection and the power supply device comprising regular switching Rukoto the. The connection switching unit maintains the first connection for a period during which the first power storage unit is charged from the discharged state to the output voltage of the photovoltaic device by the photovoltaic device. The power supply device according to claim 1 . The capacitance of the first power storage unit is determined by the first power storage within a period that the first connection is maintained when the first power storage unit is charged from the discharged state by the photovoltaic device. the power supply device according to claim 1 or 2, wherein the parts is chargeable capacitance to the output voltage of the photovoltaic device. The connection switching unit moves the second connection from the first power storage unit to the second power storage by moving the charge stored in the first power storage unit to the second power storage unit in a discharged state. The power supply device according to any one of claims 1 to 3 , wherein the power supply device is maintained for a period of time until the value of the current flowing to the section becomes lower than a predetermined value. A current limiting unit that limits a current flowing from the first power storage unit to the second power storage unit to be equal to or less than an allowable value for charging the second power storage unit as the predetermined value; The power supply device according to claim 4 , wherein the power supply device is characterized. A scanner power supply device that supplies power to a scanner that generates image information by optically scanning the document by moving a scanner head including a light source relative to the document,
A moving unit that moves according to the scanner head;
A main body provided in the scanner main body,
The moving unit is
A photovoltaic unit that generates charges by receiving light from the light source;
A first power storage unit for accumulating charges generated by the photovoltaic unit;
A first connection terminal for electrically connecting the moving part to the main body part;
A connection switching unit that alternately switches the connection of the first power storage unit to the photovoltaic power generation unit and the connection of the first power storage unit to the first connection terminal;
The main body is
A second connection terminal for electrically connecting the main body part to the moving part via the first connection terminal;
A second power storage unit that receives charges accumulated in the first storage unit via the first connection terminal and the second connection terminal;
The first connection terminal and the second connection terminal are connected when the scanner head is in a predetermined arrangement state with respect to the scanner body,
Said connection switching exchange unit, a scanner, characterized in that said first connecting terminal and the second connecting terminals when connected, connecting the first power storage unit and the first connection terminal Power supply. A plurality of the second connection terminals are provided on the main body,
The first connection terminal and the plurality of second connection terminals may include a plurality of the connection states of the scanner head and the scanner main body while the scanner head moves relative to the document. The scanner power supply device according to claim 6 , wherein the scanner power supply devices are respectively connected in the arrangement state. The power supply device for a scanner according to claim 7 , wherein the second power storage unit has a capacitance larger than a capacitance of the first power storage unit. A third power storage unit for supplying power to the scanner body;
A charge transfer unit that moves the charge stored in the second power storage unit to the third power storage unit;
A current limiting unit that limits a current flowing from the second power storage unit to the third power storage unit to be equal to or less than the predetermined value;
Said first power storage unit and said second power storage unit is characterized in that it is constituted by a capacitor, the scanner power supply device according to claim 7 or 8. An image forming apparatus,
A scanner that optically scans the document by generating a scanner head including a light source relative to the document to generate image information;
A power supply for supplying power to the scanner,
The power supply device
A moving unit that moves according to the scanner head;
A main body provided in the scanner main body,
The moving unit is
A photovoltaic unit that generates charges by receiving light from the light source;
A first power storage unit for accumulating charges generated by the photovoltaic unit;
A first connection terminal for electrically connecting the moving part to the main body part;
A connection switching unit that alternately switches the connection of the first power storage unit to the photovoltaic power generation unit and the connection of the first power storage unit to the first connection terminal;
The main body is
A second connection terminal for electrically connecting the main body part to the moving part via the first connection terminal;
A second power storage unit that receives charges accumulated in the first storage unit via the first connection terminal and the second connection terminal;
The first connection terminal and the second connection terminal are connected when the scanner head is in a predetermined arrangement state with respect to the scanner body,
Said connection switching exchange unit image to the when the first connecting terminal and the second connecting terminal is connected, characterized by connecting the first connecting terminal and the first power storage unit Forming equipment.

Images