EXTERNAL POWER SUPPLY DEVICE

Abstract: A portable game machine can selectively use a battery or an external power source as a power source. An external power supply device, when driving the portable game machine using the external power source, connects the external power source and the portable game machine to each other. The external power supply device is provided with a plug body and a power line. The plug body is formed in roughly the same shape as the button battery, and is attached detachably to a battery attachment part. Additionally, the power line extends from the plug body and is connected to the external power source.

Description: DESCRIPTION EXTERNALPOWER SUPPLY DEVICE Background of the Invention Field of Technology The present invention relates to an external power supply device for connecting a power supply line from an external power source to the main unit of an electric device that can selectively use a battery and an external power source as a power supply when driving the aforementioned electric device using the aforementioned external power source. Background of the Invention In recent years, electrical devices that can be used both indoors and outdoors have become widespread and have gained popularity. For example, some portable game machines are constituted so that they can be driven using a battery or a commercial power supply. Such portable game machines generally incorporate a so-called button battery for supplying power to the constituent circuits of the portable game machine. Furthermore, in such portable game machines, an external power supply terminal is also provided in order to allow power to be supplied to the constituent circuits from an external power source (such as a commercial power supply) in addition to the button battery. By connecting a terminal extending from an AC adapter to this external power supply terminal and connecting a separate terminal extending from the AC adapter to the connection terminal on the commercial power supply side, the portable game machine can be driven using the commercial power supply. As described above, in a portable game machine, the button battery and the external power source can be used selectively as the power supply. Accordingly, the aforementioned button battery is used as the power supply when playing a game outdoors. On the other hand, when playing a game indoors, the button battery may be used, or the portable game machine may be driven by means of an external power source through an AC adapter, etc. Nevertheless, electric devices which can selectively use a battery or an external power source as a power supply and utilized with the portable game machines as described above, have the following disadvantages: (1) Both a terminal for the battery and a terminal for the external power source must be provided. This increases the size of the device main unit. Additionally, the electrical and mechanical structure is complex. Ultimately, this results in reduced reliability and increased cost. (2) When the device is connected with an external power source while a battery is set in the device main unit, it is necessary to provide a circuit which gives the external power source precedence over the battery, a circuit which prevents reverse current flow into the battery, or a similar means. In such cases, too, reliability is reduced and costs are increased. (3) When an external power source is used, for example if an inferior external power supply device (AC adapter) is used, the voltage supplied sometimes cannot be made stable. Thus, when an external power source is used, in order to stabilize the operation of the equipment in the aforementioned electronic device, it is necessary to incorporate a power stabilizing circuit into the body of the device. However, such a power stabilization circuit remains unused when only the battery is used, resulting in increased size of the device main unit and increased cost. Summary of the Invention It is the object o the present invention to solve the problems described above. It is another object of the invention to offer an external power supply device that is able to achieve reduced size, reduced cost and increased reliability of the device unit in electric devices which are able to use a battery and the external power source selectively as the power supply. In order to solve the above problems, and attain the above objects the present invention is constituted as follows. Specifically, the external power supply device of the present invention is one in which a power supply line from an external power source is connected to a main unit of an electric device that can selectively use a battery and an external power source as a power supply when driving the aforementioned electric device using the external power. The external power supply device comprises a plug unit, which is detachably installed on a battery attachment part of said main unit and has a power supply terminal that connects to a power supply terminal on a side of said main unit, and a power supply line which is provided so as to extend from said plug unit and connect to said external power source. Additionally, in the present invention, a constitution may be adopted wherein the said plug unit has a form similar to that of the battery. Moreover, the present invention may be constituted so that a connector which separates the plug unit and the external power supply side, is provided for the power supply line. Moreover, in the present invention, a constitution may be adopted wherein a relay box is provided on the power supply line. Furthermore, the relay box may be provided with a power supply stabilization circuit. Additionally, the relay box may be constituted so as to be provided with a volume [control] for changing the power level. Moreover, the plug unit may be provided with a power supply stabilization circuit. In the present invention, the main unit may have a cover member for preventing the battery installed in the battery attachment part from falling out, and the plug has a form in which the battery and the cover member can be combined as a single body. The main unit may have a cover member for preventing the battery installed in the battery attachment part from falling out, and the cover member may be provided with an insertion hole through which the power supply line leads. Brief Description of the Drawings Figure 1 is a plan view showing the external appearance of a video game unit which is a host machine of a portable game machine; Figure 2 is a perspective view showing the video game unit of Fig. 1; Figure 3 is a rear view showing a slot part of the video game unit of Figs. 1 and 2; Figure 4 is a block diagram showing a specific embodiment having the main parts of the video game unit of Figs. 1-3; Figure 5 is a plan view showing the external appearance of a portable game machine which is an ancillary machine of the video game unit of the present invention; Figure 6 is a perspective view of the game machine, showing the state in which the cover member is open; Figure 7 is a diagram showing a constitution of the main parts of the portable game machine of Fig. 5; Figure 8 is a perspective view of a battery housing part of the game machine; Figure 9 is a schematic perspective view showing one example of the working modes of the present invention; Figure 10 is a schematic perspective view showing the state of the plug unit, viewed from the direction of arrow A in Figure 9; Figure 11 is a perspective view explaining the state in which the plug unit is installed in the battery housing part; Figure 12 is a schematic perspective view showing another example of the mode of the game machine of the present invention; Figure 13 is a schematic perspective view showing yet a further example of the working mode of the game machine of the present invention; Figure 14 is a schematic perspective view showing yet another example of the working mode of the game machine of the present invention; Figure 15 is a partial side view of the game machine; Figure 16 is a schematic perspective view of a further example of the working mode of the present invention; Figure 17 is a bottom view showing still another example of the working mode of the present invention; Figure 18 is a rear view of an arrangement of a base plate and a battery holder in the game machine; Figure 19 is a rear view of the battery holder; Figure 20 is a sectional view of the battery holder. Figure 21 is a rear view showing an arrangement of the base plate and battery holder in the state in which the plug unit is installed; Figure 22 is a rear view of the battery holder in the installed state shown in Fig. 21; Figure 23 is a perspective view of another embodiment of the battery holder; Figure 24 is a perspective view showing the inside of the battery holder; Figure 25 is perspective view for explaining the state in which the plug unit is inserted into the battery holder of the game machine; Figure 26 is a schematic perspective view showing major parts in yet another working mode of the game machine of the present invention; and Figure 27 is a schematic perspective view showing the major parts in the state in which the plug unit is inserted into the game machine. Detailed Description of the Preferred Embodiments Next, preferred embodiments of the present invention will be explained referring to the figures. In the embodiments 1 through 6, the present invention is applied in a portable game machine that is detachable from a commonly known video game unit. First, prior to explaining the external power supply device of the present invention, a brief explanation is given concerning the portable game machine in which the external power supply device is used, and the video game unit which functions as a host machine for this portable game machine. [Constitution of video game device (host machine)] Figures 1 and 3 show external views of a video game device 1. The video game device 1 reads out a game program recorded on, e.g., an optical disk and executes the program in accordance with directions from a user (game player). A main unit 2 of the video game device 1 comprises a disk installation part 3, a reset switch 4 for resetting the game as desired, a power supply switch 5, a disk operating switch 6 for operating the installation of the optical disk and, e.g., 2 slot parts 7A and 7B. In the disk installation part 3, an optical disk such as a CD-ROM, which serves as a recording medium for providing application programs such as video games, is installed. The slot parts 7A and 7B, as shown in Figure 1 through Figure 3, are provided on the front of the main unit 2 (the lower face in Figure 1, the diagonal left face in Figure 2 and the front in Figure 3), and are each connected to a control device (controller) 20. Additionally, as described below, a memory card 10 (see Figure 4) and a portable game machine 100 are installed by insertion into the slot parts 7A and 7B. In the embodiment shown in the figures, slot parts 7A and 7B each are formed in two upper and lower stages. In the upper stage, memory card insertion parts 8A and 8B are provided, into which the memory card 10 or the portable game machine 100, which serves as the ancillary machine, is inserted and installed. Controller connection parts (jacks) 9A and 9B, to which the connection terminal parts (connectors) 26 of the controller 20 are connected, are installed in the lower stage. Figure 1 and Figure 2 show a state in which a portable game machine 100 has been inserted into the memory card insertion part 8A. The controller 20 inputs directions provided by an operation performed by the user while playing a game. The controller 20 comprises first and second operating parts 21 and 22, a left button 23L, a right button 23R, a start button 24, a selection button 25, operating parts 31 and 32, which are able to perform analog operation, a mode selection switch 33, which selects the operating mode of operating parts 31 and 32, and a display part 34 for displaying the operating mode selected. [Circuit configuration of the video game device] Next, Figure 4 schematically shows an example of the circuit configuration of the main parts of the video game device 1. The video game device 1 is provided with a control system 50, a graphics system 60, a sound system 70, an optical disk control part 80, which performs control of optical disks, a communications control part 90, and a bus BUS, to which the aforementioned parts 50, 60, 70, 80, and 90 are connected, etc. When the power is switched on in the video game device 1, a central processing unit (CPU) 51 runs an operating system stored in the ROM 54. By this means, the CPU 51 performs control of the graphics system 60, sound system 70, etc. When the operating system is run, the CPU 51 performs operation verification, general initialization of the video game device 1, and then controls the optical disk control part 80 and executes an application program such as a game stored on an optical disk. In running this game or other program, CPU 51 controls the graphics system 60, sound system 70, etc., in accordance with the input entered by the user, and thus controls the display of images and the generation of sound effects and music. The communications control part 90 controls the input and output of signals from the controller 20 through which instructions from the user are input along with the input and output of data from the memory card 10 storing the game settings, etc., and data from the portable game machine 100. For this purpose, the communications control part 90 is provided with a communications controller 91, which controls communication with the CPU 51 via the bus BUS. The communications controller 91 is provided with controller connecting parts 9A (9B), to which the controller, which inputs instructions from the user, is connected, and memory card insertion parts 8A and 8B, to which the memory card 10 and portable game machine 100 are connected, as an auxiliary storage device which stores game settings and like data. The communications controller 91 also houses a protection circuit for preventing electrical failure. The memory card 10 and portable game machine 100 are separated from the bus BUS, and can be installed or detached while the power of the video game device 1 is on. Thus, when the storage capacity of the memory card 10 or portable game machine 100 is insufficient, a new memory card 10 can be inserted and installed without switching off the power of the main unit 2. As a result, a new memory card 10 can be inserted and installed without losing game data requiring backup, and the necessary data can be written into this new memory card 10. [Constitution of a portable game machine (ancillary machine)] Next, the portable game machine 100 which serves as the ancillary machine of the video game device 1 will be explained. The portable game machine 100 can be installed by insertion into the memory card insertion parts 8A and 8B provided on the slot parts 7A and 7B of the video game unit 1 which serves as the host machine. Also, the portable game machine 100 can be used as an individual memory card corresponding to one of several connected controllers 20. For example, when two users (game players) play a game, the respective game results, etc., may be recorded individually into two portable game machines 100. The portable game machine 100, as shown in Figure 5 through Figure 7, is provided with an operating part 120, which has one or multiple operating pieces 121 and 122 for performing event input, various selections, etc., a display part 130 comprising a liquid crystal display unit (LCD) or the like, and a (window part constituting) a wireless communication unit 140, through which wireless communication is performed using an infrared beam or the like, on the front face of a housing 101 which constitutes the outer casing. Furthermore, as shown in Figure 6, the housing 101 is also provided with a connector part 150, which is connected to the power supply terminal on the video game device 1 side and the signal terminal when the portable game machine 100 is inserted into the slot part 7A or 7B. The connector 150 is covered by a cover 110 when the portable game machine 100 has been installed by insertion into slot part 7A (7B), and is exposed when the cover 110 is released (opened) as shown in Figure 6. The main part of the portable game machine 100, as shown in Figure 7 (a), comprises a control unit 41 for controlling the operation of the game machine, a connecting connector 42 for connecting with the slot parts 7A and 7B, and a nonvolatile memory 46, which is a data storage element. Of course, an interface for connection with the video game device 1 that is the host machine is also provided. Furthermore, the portable game machine 100 is also provided with a clock unit 45 and a sound generating unit 47, such as a speaker. The clock unit 45 and sound generating unit 47 are each connected to the control unit 41, and operate under control by the control unit 41. The control unit 41 comprises a microcomputer, etc. As the nonvolatile memory 46, a flush memory such as an EEPROM (electrically erasable programmable ROM) is used. Figure 7 (b) shows the control items of the control unit 41. Normally, the memory card 10 is provided with two interfaces, a main unit connection interface for the video game machine 1 and a memory interface for inputting and outputting data to and from the memory. On the other hand, the portable game machine 100, in addition to the interfaces, is also provided with a display interface, an operating input interface, a voice interface, a wireless communication interface, a clock control, and a program download interface. The portable game machine 100 has a function which stores application programs and programs downloaded from the video game device 1 in a program memory part 41a. For this reason, the application programs and various driver software which are run on the portable game machine 100 can be changed easily. Thus, using the portable game machine 100, operation can be controlled independently from the video game device 1. Accordingly, on the portable game machine 100 side, data stored in the program memory part 41a can be created independently from the application software on the video game device 1 side. Moreover, coordinated operation (linkage) between the portable game machine 100 and video game device 1 can be achieved by exchanging data with the video game device 1. The portable game machine 100 internally houses a so-called button battery 49. Specifically, as shown in Figure 8, a battery housing part 181 for receiving the button battery 49 is located on the back face of the housing 101 of the portable game machine 100. The battery housing part 181 comprises a positive power terminal 181a on the peripheral area thereof, and a negative power terminal 181b on the base part thereof. Furthermore, the battery housing part 181 can be opened and closed by means of a cover member 182, as shown in Figure 8. The cover member 182 comprises an engagement piece 182a which engages with an engagement slot 183 provided on the housing 101, and a screw insertion hole 182b corresponding to a screw attachment hole 184 provided on the housing 101. After the button battery 49 has been housed in the battery housing part 181, the engagement piece 182a is engaged with the engagement slot 183, and the screw 185 is inserted through the screw insertion hole 182b and screwed into the screw attachment hole 184, thereby attaching the battery housing part 181 to the housing 101 in a closed state. By this means, the button battery 49 can be effectively prevented from accidentally falling out of the housing part 181. Although omitted from the figure, behind a hole formed in the housing 101, on the back face of the housing 101, a reset button for returning the setting status to that when shipped from the factory is provided, and the button can be depressed by a pin or like instrument. The portable game machine 100, being constituted as described above, can also be operated when removed from the slot part 7A or 7B of the video game machine 1. A rechargeable secondary battery may also be used as a battery 49. Moreover, when the portable game machine 100 has been inserted into a slot part 7A or 7B, power is supplied from the video game device 1 that is the host machine. Specifically, as shown in Figure 7A, a power terminal 55 is connected via a reverse current flow prevention diode 56 to the connecting terminal of the button battery 49. When the portable game machine 100 has been inserted into slot part 7A or 7B, power is supplied from the video game device 1 to the portable game machine 100. Moreover, when a secondary battery is used, recharging of the secondary battery may be performed. Next, an external power supply device according to the present invention as used in a portable game machine 100, which is the ancillary machine of a video game device 1 that serves as the host machine as described above, is explained in detail referring to the drawings. Figure 9 through Figure 11 show an external power supply device 186 according to a first example of the working mode of this invention. As shown in the drawings, the external power supply device 186 in this mode connects an external power source to a portable game machine 100 when driving the portable game machine 100 by an external power source instead of the button battery 49. In the case of the mode shown, the portable game machine 100 is connected to a commercial power supply via an AC adapter 187. The external power source 187 as referred to in this Specification can be understood to include the AC adapter. The external power supply device 186 has a plug body 188. The plug body 188 is detachably held in a battery container 181 (see Figure 8). The plug body 188 is formed in approximately the same form as a form of the button battery 49 and cover member 182 (see Figure 8) combined as a single unit; i.e., it is composed of a battery- form part 189 and a cover part 190. By forming the plug body 188 as described above, not only can the number of parts of the external power supply device 186 be reduced, but also the installation into the battery housing part 181 can be simplified. The cover part 190 is provided with an engagement piece 190a and a screw insertion hole 190b in the respective positions corresponding to the engagement piece 182a and screw insertion hole 182b of the cover member 182 as seen in Fig. 9. A power supply line 191 leads from the upper face of the cover part 190 and is connected to the external power source 187. The battery-form part 189, as shown in Figure 10, is provided with an anode 189a which comes in contact with the positive power terminal 181a, and a cathode 189b, which comes in contact with the negative power terminal 181b. After the plug body 188 is then housed in the battery housing part 181, the engagement piece 190a is engaged with the engagement slot 183, the screw 185 is inserted through the screw insertion hole 190b and screwed into the screw attachment hole 184, and thereby the plug body 188 is attached to the housing 101 with the battery housing part 181 in a closed state. By this means, the plug part 188 can be housed in the battery housing part 181. Of course, the plug body 188 can be freely attached to and detached from this housing 101. Due to this configuration, by inserting the plug body 188 instead of the button battery 49 into the battery housing part 181, external power can be supplied to the constituent circuits of the portable game machine 100. Thus, it is no longer necessary to provide the housing 101 with a terminal for external power, and the housing 101 can be reduced in size. Moreover, the electrical and mechanical structures are also simplified. As a result, reliability can be increased and cost reduced. Furthermore, since the plug body 188 is not connected when the button battery 49 is set in the battery housing part 181, it is no longer necessary to provide a circuit which gives precedence to the external power source 187 over the button battery 49, or a circuit for prevention of reverse current flow into the button battery 49. By this means, too, reliability is improved and cost is reduced. In this way, the portable game machine 100 can be reduced in size, reduced in cost, and increased in reliability, despite the fact that external power can be supplied to the portable game machine 100. Next, Figure 12 shows a second example of the working modes of the present invention. In this example, as shown in Figure 12, connectors 192A and 192B are provided along the power supply line 191, and the plug body 188 and external power source 187 are formed separately. By means of this example, an existing form can be used as the external power source 187, and the device can be reduced in cost. Otherwise, the structure and operation are similar to those of the first example. Next, Figure 13 shows a third example of the working mode of the present invention. In this example, a relay box 193 is provided along the power supply line 191 in the structure shown in the second example described above. In this working mode, a relay box 193 is provided between the connector 192A of the power supply line 191 and the external power source 187. Further, a voltage control 194 is housed inside the relay box 193. This volume 194 can be operated by turning an operating screw 195 provided on the front of the relay box 193. By this means, voltage from the external power source 187 undergoes voltage conversion and is supplied to the plug body 188. Testing terminals 196a and 196b, which are connected to the anode 189a and cathode 189b, respectively, are provided on the surface of the cover part 190 of the plug body 188. By means of testing terminals 196a and 196b, the voltage converted by the voltage control 194 can be detected. The testing terminals 196a and 196b under normal conditions are covered by a seal 197 affixed to the surface of the cover 190. Additionally, by providing a jack (not shown in the drawing) for connection of the external power source (AC adapter) 187 on the relay box 193, the relay box 193 and external power source 187 are made separate, and by installing the plug (not shown) of the external power source 187 in the jack, the relay box 193 and external power source (AC adapter) 187 can be connected. Otherwise, the structure and operation are similar to those of the first example described above. Next, Figure 14 and Figure 15 show a fourth example of the working mode of the present invention. In this example, the relay box 198 is directly connected to the power supply line 191 extending from the plug body 188. A jack 199 is provided on the side portion of the relay box 198, allowing the plug leading to the external power source to be installed. As shown in Figure 15, in conjunction with the installation of the portable game machine 100 in the memory card insertion part 8A (8B), when the connector 26 of the controller 20 is connected to the controller connecting part 9A (9B), the power supply line 191 is made to lead out from the gap d between the portable game machine 100 and connector 26, and the connection box 198 is located on the outside thereof. When the portable game machine 100 is inserted and installed into slot part 7A (7B) and the portable game machine 100 is set so as to be used with an external power source 187, when the situation occurs wherein only the video game unit 1 is used, the plug of the external power source is removed from the jack 199. By this means, the external power source and portable game machine 100 are disconnected. Since it is not necessary to remove the plug body 188 from the portable game device 100, operability is improved. Otherwise, the structure and operation are similar to those in Example 1 described above. Moreover, by using the housing 101 of the portable game machine 100 as a relay box 198, cost can be reduced. Additionally, in each of the first to fourth examples, the plug body 188 and relay boxes 193 and 198 are provided with filter circuits, which are power stabilization circuits. Since such constitutions make it unnecessary to provide a power stabilizing circuit, etc., inside the portable game machine 100, the size and cost of the portable game machine 100 can be reduced. Next, Figure 16 shows a fifth example of the working mode of the present invention. In this example, a plug body 200 having roughly the same form as the button battery 49 (see Figure 8) is used. Specifically, in the examples described above, a plug body 188 (see Figure 9 through Figure 14) having roughly the same form as the button battery 49 and cover member 182 formed as a single unit was used, but in the present example, as shown in Figure 16, the plug body 200 has roughly the same form as the button battery 49. This plug body 200 is constituted in a roughly disk-shaped form similar to the button battery 49, having an anode 200a on its perimeter and a cathode 200b on its main surface. The anode 200a comes in contact with the positive power terminal 181a, and the cathode 200b with the negative power terminal 181b. Additionally, a power line 191, which is connected to the external power source, extends from the upper face of the plug body 200. In this mode, a notch (insertion hole) 182c for inserting the power line 191 extending from the plug body 200 housed in the battery housing part 181 is provided on the cover member 182. After the plug body 200 has been housed in the battery housing part 181, by engaging the engagement piece 182a with the engagement slot 183, and next inserting the screw 185 into the insertion hole 182b and screwing it into the screw attachment hole 184, this cover member 182 is attached to the aforementioned housing 101 in a state such that the battery housing part 181 is closed. This configuration, like that in the previous working modes, allows the external power source to be supplied to the constituent circuits of the portable game machine 100 by insertion of the plug body 200 instead of the button battery 49 into the battery housing part 181. Moreover, since the plug body 200 has a form roughly similar to that of the button battery 49, it can be used in various devices regardless of the form of the cover member 182, if it matches the form of the button battery 49. In this example, too, relay boxes 193 and 198 or power stabilizing circuits such as filter circuits may be provided as in the previous examples. Otherwise, the structure and operation are similar to those in first example described above. Next, Figure 17 through Figure 22 show a sixth example of the working mode of the present invention. In this example, the present invention is applied to a portable game machine 110, which is constituted so as to hold a button battery 49 in a battery holder 104. Here, the battery holder 104 is provided so as to be detachable on a through-hole formed on the back face of a portable game machine 100, so that this through-hole is closed. The battery holder 104, as shown in Figure 18 through Figure 20, holds the button battery 49 which supplies power to the electronic circuit part inside the housing 101 of the portable game machine 100. When this battery holder 104 is attached to the housing 101, the peripheral edge of the button battery 49, which constitutes an anode, comes in contact with the positive power terminal 154 provided on the base plate 151 forming part of the game machine 100, and the main surface, which constitutes a cathode, comes in contact with the negative power terminal 153 provided on the base plate 151. In this way, by bringing the button battery 49 into contact with the power terminals 153 and 154, it is connected with the electronic circuit part on the base plate 151, and power is supplied to this electronic circuit part. The battery holder 104 is formed roughly in a disk shape slightly larger than the button battery 49, as shown in Figure 19 and Figure 20, and has bracket-shaped battery holding parts 104a and 104b for holding the peripheral edges of the button battery 49. The battery holding parts 104a and 104b, as shown in Figure 20, are formed so as to have end parts which follow the peripheral edge of protruding parts 156 of the cathode when holding the peripheral edge of the button battery 49. The button battery 49 cannot be inserted between the battery holding parts 104a and 104b due to the protruding part 156 when the cathode is facing the battery holder 104. Only when the anode is facing the battery holder 104 can it be inserted between the battery holding parts 104a and 104b, in a position in which the protruding part 156 is protruding from between the battery holding parts 104a and 104b. Specifically, the battery holding parts 104a and 104b function as mis-insertion preventing members, which prevent the button battery from 49 from being held in a direction opposite the specified pole direction in relation to the battery holder 104. Meanwhile, when the external power source 187 is used in place of the button battery 49, the plug body 200 in the fifth example described above is held as shown in Figure 16 in the battery holder 104. Figure 21 and Figure 22 show the state in which it is held. A notch (insertion hole) 104g for insertion of the power line 191 leading from the plug body 200 is formed on the battery holder 104. In the structure of the sixth example, since the single battery holder 104 is used in combination for holding both the button battery 49 and the plug body 200, the notch 104g is provided on the battery holder 104, but a battery holder not having a notch 104g for holding the button battery 49 and a battery holder having a notch 104g for holding the plug body 200 may be provided separately. In this example also, relay boxes 193 and 198 or power stabilizing circuits such as filter circuits may also be provided as described above. Otherwise, the structure and operation are similar to those in the first example of the working mode described above. The battery holder 104 may also adopt a form like that shown in Figure 23 through Figure 25. In this case, this battery holder 104 is provided with engagement claws 104e and 104e, which engage with the edge of engagement slots formed on the housing 101 of the portable game machine 100, and a screw hole 104d for screw attachment. A screw 104c, which is screwed into a screw hole (not shown in the figure) in the housing 101, is inserted into this screw hole 104d. The battery holder 104, like the structure shown in Figure 17 through Figure 22, has battery holding parts 104a and 104b on its backside, and thus holds the button battery 49 in the specified pole direction between the battery holding parts 104a and 104b. The battery holder 104 is also provided with a notch (insertion hole) 104f for inserting the power line 191 which is extended from the plug body 200. Thus the plug body 200 can be placed between the battery holding parts 104a and 104b in the specified pole direction. Next, Figure 26 and Figure 27 show a seventh example of the working mode of the present invention. The structures of examples 1 through 6 were explained with regard to cases in which the present invention is applied in a portable game machine 100 using the button battery 49, but in this example, the present invention is applied in an electrical product (e.g., electric shaver) that is able to use a commercial power supply or a widely used size AA battery. Specifically, as shown in Figure 26, the electrical product or device 201 is constituted so that a size AA battery 204 is inserted along the axial direction from the anode 204a side and held in the battery housing part 203 provided in the main unit 202 of the device. The detachable cover member 205 is attached to the insertion opening 203a of the battery housing part 203. Engagement pieces 205a (only one of which is shown in the figures) are provided at both ends in the crosswise direction of the cover member 205. At the same time, engagement parts 203b and 203b, with which the engagement pieces 205a and 205a are engaged, are placed in the peripheral area of the insertion opening 203a to the device main unit 202. A positive power terminal, not shown in the figure, with which the anode 204a of the size AA battery 204 comes in contact, is placed inside the battery housing part 203. Additionally, a negative power terminal (not shown), which comes in contact with the cathode 204b of the size AA battery 204, and wiring (not shown), which connects with the device main unit 202 side, are arranged on the inner face of the cover member 205. When the electrical product or device 201 is driven using an external power source instead of the size AA battery 204, as shown in Figure 27, a plug body 206 of the external power supply device 186 is inserted into the battery housing part 203. The plug body 206 is formed in roughly an equivalent shape as the combined size AA battery 204 and cover member 205. In other words, it comprises a battery-form part 207 having roughly the same form as the size AA battery 204 and cover part 208, which is provided on the cathode side of this battery- form part 207 having roughly the same form as the aforesaid cover member 205. An anode 207a, which is in contact with a positive power terminal (not shown) placed inside the battery housing part 203, is provided on the battery-form part 207. A lid part 208 is provided with engagement pieces 208a and 208a in positions corresponding to the engagement pieces 205a and 205a of the cover member 205. A power line 191 leads from the outer face of the cover part 208 and is connected to an external power source. Additionally, wiring (not shown) connecting to the device main unit 202 side is provided on the cover part 208. Otherwise, the structure and operation are similar to those in Example 1 described above. In the examples described above, examples in which a commercial power supply is used as the external power source were described, but a standard automobile cigarette lighter socket, or sources other than a commercial power supply may be used as the external power source. In the structure of Example 7, an electrical product using a size AA battery was discussed, but of course the present invention may also be applied to electrical products which use dry power cells of varying sizes such as size C and size D batteries. As explained above, the present invention offers the highly desirable effect of reducing the size of the device main unit and cost while increasing reliability in a device which is able to supply power from an external source to a battery terminal in the main unit of the device

Claims: CLAIMS 1. An external power supply device for connecting an external power source to a device main unit of an electrical product which can selectively use a battery or an external power source as a power supply, the external power supply device comprising: a plug unit which is detachably installed on a battery attachment part of said main unit and has a power supply terminal that is connected to the power supply terminal on a side of said main unit; and a power supply line which extends from said plug unit and is connected to said external power source so that said electrical product is driven by said external power source. 2. The external power supply device according to claim 1, wherein said plug unit has a plug body formed in roughly the same shape as said battery. 3. The external power supply device according to claim 1, further comprising a connector provided on said power line, said connector making a plug unit part and an external power source part separate bodies. 4. The external power supply device according to claim 1, and further comprising a relay box provided on said power line. 5. The external power supply device according to claim 4, wherein said relay box includes a power stabilization circuit. 6. The external power supply device according to claim 4, wherein said relay box is provided with a voltage control for changing a power level. 7. The external power supply device according to claim 1, wherein said plug unit is provided with a power stabilization circuit. 8. The external power supply device according to claim 1, wherein said main unit includes a cover member for preventing the battery installed in said battery attachment part from dropping out, and said plug unit has a plug body formed in the shape of said battery and said cover member formed as a single body. 9. The external power supply device according to claim 1, wherein said main unit has a cover member for preventing the battery installed in said battery attachment part from dropping out, and said cover member is provided with an insertion hole through which said power line leads. 10. The external power supply device according to claim 2, and further comprising a connector provided on said power line said connector a plug unit part and an external power source part separate bodies. 11. The external power supply device according to claim 5, wherein said relay box is provided with a voltage control for changing a power level.

Inventors: OOTORI YASUHIRO, OOTORI, YASUHIRO
Applicants: SONY COMP ENTERTAINMENT INC, SONY COMPUTER ENTERTAINMENT INC.
Application year: 2000
Main classification: H02J7
IPC codes: A63F13, H01M2, H02J7