Patent Publication Number: US-2003230196-A1

Title: Oxygen supply device

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to an oxygen supply device, and more particularly, to an oxygen supply device for common use in a vehicle and a place indoors, that generates oxygen and supplies the same to the vehicle or a place indoors, in which an oxygen concentration display can be provided for operating in combination with the oxygen supply device for vehicle- or indoor-use.  
       [0003] 2. Description of the Related Art  
       [0004] In a case where a heater or an air-conditioner is operated at the state where a ventilation means or window is closed in a vehicle or partitioned room as is well-known, air in the vehicle or in the partitioned room becomes dirty within a short period of time and the oxygen concentration becomes remarkably lower. Such air pollution and lowering of oxygen concentration can make passengers including a vehicle driver or indoor residents feel fatigue or discomfort easily. Accordingly, air-conditioning systems, such as various air cleaning devices or oxygen generators, can be installed in a vehicle or a place indoors.  
       [0005] The oxygen generator is a mechanical device for separating oxygen from air that has been taken in and supplying the separated oxygen inside of the vehicle or room. Most of the conventional oxygen generators adopt a pressure swing adsorption (PSA) method. In the PSA method, oxygen is obtained when air passes alternately through two columns in which zeolite is charged. In this case, since the structure is complicated and the weight is very heavy, the oxygen generator should be fixedly installed and used in a certain place due to the limited possibilities of installation and the difficulty in moving and removing the same.  
       [0006] Also, since the oxygen generator does not display an indoor oxygen concentration level, users cannot verify whether they are in an environmental state of a normal oxygen concentration or an environmental state of optimal oxygen concentration. In this respect, the oxygen generator cannot provide sufficient physical and psychological satisfaction to users.  
       [0007] In addition, since the PSA method oxygen generator should counter-clean zeolite adsorbing oxygen, the oxygen production amount is not great in comparison with the system size and the oxygen concentration is not always constant.  
       SUMMARY OF THE INVENTION  
       [0008] To solve the above problems, it is an aspect of the present invention to provide an oxygen supply device for generating oxygen of a constant concentration with a simple structure and operational mechanism, as well as a compact case where various components, such as an oxygen separator and a pump mechanism, are contained to thereby allow a user to easily mount and dismount the oxygen supply device in and from a vehicle and a room as necessary to facilitate hand-carrying thereof.  
       [0009] It is another aspect of the present invention to provide an oxygen supply device having a display for enabling users to verify a current oxygen concentration to ease the users.  
       [0010] It is still another aspect of the present invention to provide an oxygen supply device not only for discharging condensed water generated during oxygen generation under the control of a controller but also for automatically dispensing the condensed water when a vehicle supplied with the oxygen supply device stops, thereby simplifying management.  
       [0011] To accomplish the above aspect of the present invention, there is provided an oxygen supply device comprising: an oxygen generator installed in a case having an air inflow inlet and an oxygen discharging outlet, wherein said oxygen generator comprises: a pump for receiving external air through the air inflow tube and pumping the air flowing in the air inflow tube, after being activated by an applied external power source; an oxygen separator connected to the pump, through which air discharged from the pump to pass and oxygen is separated and generated from the air to be discharged through the oxygen discharging tube; a wet oxygen prevention unit for preventing water drops from being discharged through the oxygen discharging tube; and a controller for controlling the pump and the wet oxygen prevention unit.  
       [0012] Also, the oxygen supply device further comprises an oxygen concentration sensor for sensing an indoor oxygen concentration when oxygen produced from the oxygen generator is supplied and a display connected to the oxygen concentration sensor for displaying the sensed oxygen concentration thereon.  
       [0013] Also, a percentage value of an oxygen concentration ratio of a current oxygen concentration with respect to a desired oxygen concentration is displayed on the display.  
       [0014] Also, the oxygen supply device further comprises a manipulator for sending a control signal to the controller so as to perform a predetermined control operation.  
       [0015] Also, the manipulator and the display are connected with each other to form a control panel, in which a desired oxygen concentration input button for inputting a desired oxygen concentration into the controller is provided on the manipulator and at least one display window for displaying an oxygen concentration thereon is provided on the display.  
       [0016] Also, the wet oxygen prevention unit comprises a condensed water trap through which oxygen separated by the oxygen separator passes and for separating condensed water generated due to a variation in an oxygen pressure from the passing oxygen to thereby transfer the moisture removed oxygen to the oxygen discharging tube; and a condensed water drainage valve, which is closed when power is applied and open when power is not applied, for dispensing the condensed water collected in the condensed water trap.  
       [0017] In addition, the wet oxygen prevention unit is a heater, which is installed between the pump and the oxygen separator, for heating the air flowing into the oxygen separator so as to prevent condensed water from being produced by the oxygen pressure variation.  
       [0018] Also, the oxygen supply device further comprises a second pump, which is installed between the oxygen separator and the oxygen discharging tube, for taking in the oxygen discharged from the oxygen separator and transferring the oxygen that has been taken in to the oxygen discharging tube.  
       [0019] Also, the oxygen supply device further comprises at least one ultraviolet sterilizer for sterilizing bacteria in the air or oxygen in the oxygen supply device so that the oxygen discharged through the oxygen discharging tube is purified.  
       [0020] Also, an oxygen supply line for transferring oxygen to a place where oxygen is needed is connected to the oxygen discharging tube.  
       [0021] Also, the oxygen supply line is configured so that an end of the oxygen supply line is extended into an air discharging grill to thereby discharge oxygen through the grill when the oxygen supply device is applied to a vehicle.  
       [0022] Also, the oxygen supply line comprises at least one diffusion nozzle, which is installed on the inner ceiling on the driver&#39;s side, for spraying oxygen downwards when the oxygen supply device is applied to a vehicle.  
       [0023] Also, the oxygen supply line is configured so that an end of the oxygen supply line is extended toward a sun visor at the upper portion of a driver&#39;s seat to thereby discharge oxygen from the sun visor, in which the oxygen concentration sensor is installed on the control panel.  
       [0024] Also, a second condensed water trap for collecting and dispensing the condensed water produced in the inside of the oxygen supply line is further provided in a predetermined place along the oxygen supply line.  
       [0025] Also, the control panel is fixed to the sun visor and an end of the oxygen supply line is fixed to the control panel.  
       [0026] In addition, an end of the oxygen supply line passes through the inside of the control panel and is connected to a flexible tube with which a discharging direction of oxygen can be adjusted in a desired direction.  
       [0027] Also, the manipulator further comprises a warning lamp for informing a user that the condensed water should be emptied from the condensed water trap, and a condensed water drainage button for disconnecting power applied to the condensed water drainage valve via the controller to thereby open the condensed water drainage valve.  
       [0028] Also, the manipulator further comprises a heater on/off button for turning the heater on or off via the controller.  
       [0029] In addition, the power applied to the controller in the oxygen generator is a commercialized alternating-current (AC) power.  
       [0030] Accordingly, an inverter for inverting an externally supplied direct-current (DC) power into an AC power is further provided in the oxygen supply device when the oxygen supply device is applied to a vehicle.  
       [0031] Also, the oxygen separator is a hollow thread-film or flat-film oxygen separator.  
       [0032] Also, a discharged oxygen concentration sensor for sensing the concentration of the oxygen discharged through the oxygen discharging tube and transferring the sensed oxygen concentration to the controller so as to be displayed on the display is provided in a place along the oxygen discharging tube in the oxygen generator. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0033] The above aspects and other advantages of the present invention will become more apparent by describing the preferred embodiments thereof in greater detail with reference to the accompanying drawings in which:  
     [0034]FIG. 1 is a schematic configurational diagram explaining a basic configuration of an oxygen supply device according to the present invention;  
     [0035]FIG. 2 shows an example of a power source for use with an oxygen supply device according to the present invention;  
     [0036]FIG. 3 shows another example of a power source for use with an oxygen supply device according to the present invention;  
     [0037]FIGS. 4A and 4B are schematic configurational diagrams showing examples when each oxygen supply device according to the first and second embodiments of the present invention is applied to a vehicle;  
     [0038]FIGS. 5A and 5B are schematic configurational diagrams showing other examples when each oxygen supply device according to the first and second embodiments of the present invention is applied to a vehicle;  
     [0039]FIGS. 6A and 6B are schematic configurational diagrams showing still other examples when each oxygen supply device according to the first and second embodiments of the present invention is applied to a vehicle;  
     [0040]FIG. 7A is a detailed diagram showing a control panel respectively shown in FIGS. 4A through 6B;  
     [0041]FIG. 7B is a side view showing a control panel of FIGS. 4A through 6B which is installed on a sun visor;  
     [0042]FIG. 8 is a schematic diagram explaining the inner structure of an oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention;  
     [0043]FIG. 9 is a schematic diagram explaining the inner structure of another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 8 oxygen generator;  
     [0044]FIG. 10 is a schematic diagram explaining the inner structure of still another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, which differs from the FIG. 8 oxygen generator;  
     [0045]FIG. 11 is a schematic diagram explaining the inner structure of yet another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 8 oxygen generator;  
     [0046]FIG. 12 is a schematic diagram explaining the inner structure of another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 11 oxygen generator;  
     [0047]FIG. 13 is a schematic diagram explaining the inner structure of still another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 11 oxygen generator;  
     [0048]FIG. 14 is a schematic diagram explaining the structure of a condensed water trap respectively shown in FIGS. 8 through 13;  
     [0049]FIGS. 15A and 15B are schematic configurational diagrams showing examples when each oxygen supply device according to the third and fourth embodiments of the present invention is applied to a vehicle;  
     [0050]FIGS. 16A and 16B are schematic configurational diagrams showing other examples when each oxygen supply device according to the third and fourth embodiments of the present invention is applied to a vehicle;  
     [0051]FIGS. 17A and 17B are schematic configurational diagrams showing still other examples when each oxygen supply device according to the third and fourth embodiments of the present invention is applied to a vehicle;  
     [0052]FIG. 18 is a detailed diagram showing a control panel respectively shown in FIGS. 15A through 17B;  
     [0053]FIG. 19 is a schematic diagram explaining the inner structure of an oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention;  
     [0054]FIG. 20 is a schematic diagram explaining the inner structure of another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differig from the FIG. 19 oxygen generator;  
     [0055]FIG. 21 is a schematic diagram explaining the inner structure of still another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator;  
     [0056]FIG. 22 is a schematic diagram explaining the inner structure of yet another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator;  
     [0057]FIG. 23 is a schematic diagram explaining the inner structure of still yet another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator;  
     [0058]FIG. 24 is a schematic diagram explaining the inner structure of a further oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator;  
     [0059]FIGS. 25A and 25B are schematic configurational diagrams showing examples when each oxygen supply device according to the first through fourth embodiments of the present invention is applied in an indoor environment; and  
     [0060]FIGS. 26A and 26B are detailed diagrams showing another control panel which can be applied to an oxygen supply device of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0061] Preferred embodiments of the present invention will be described with reference to the accompanying drawings.  
     [0062] In general, an oxygen supply device according to the present invention can be easily mounted at a particular place and dismounted from that place to be mounted at another place. For example, the oxygen supply device can be used in a living room or a study or library as well as in a vehicle. Also, a display to be described later displays the current indoor oxygen concentration as a percentage on the basis of an oxygen concentration of 20.9%, to thereby provide users with an ease in recognizing an oxygen concentration.  
     [0063]FIG. 1 is a schematic configurational diagram explaining a basic configuration of an oxygen supply device according to the present invention.  
     [0064] As shown in FIG. 1, an oxygen supply device  10  according to the present invention includes an oxygen generator  15 , which generates oxygen, a control panel  12  which sends a control signal to the oxygen generator  15  and an oxygen concentration sensor  78  which senses the oxygen concentration of the air indoors and transfers the sensed oxygen concentration to the control panel  12 .  
     [0065] The oxygen concentration sensor  78  can be positioned in a place desired by the user. Here, the oxygen concentration sensor  78  can be fixed to the control panel  12 . As will be described later, the control panel  12  includes a display and a manipulator.  
     [0066] For mutual signal transmission among the oxygen generator  15 , the control panel  12 , and the oxygen concentration sensor  78 , the oxygen concentration sensor  78  includes a signal transmitter  101  for transmitting the sensed oxygen concentration to the control panel  12 ; the control panel  12  includes a signal receiver  103  for receiving the oxygen concentration transmitted from the oxygen concentration sensor  78  and a signal transmitter  105  for generating and transmitting a control signal for controlling the oxygen generator  15 ; and the oxygen generator  15  includes a signal receiver  107  for receiving the control signal from the control panel  12 .  
     [0067] Here, the signal transmission method among the oxygen generator  15 , the control panel  12 , and the oxygen concentration sensor  78 , can be put into effect by using a well-known wired or wireless communication method.  
     [0068] Finally, the oxygen generator  15  in the oxygen supply device  10  according to the present invention generates oxygen, and the control panel  12  controls the amount of oxygen of the oxygen generator  15  and displays the current oxygen concentration in the air, while the oxygen concentration sensor  78  senses the oxygen concentration in the air so as to be displayed on the display in the control panel  12 .  
     [0069]FIG. 2 shows an example of a power source for use with an oxygen supply device according to the present invention, and FIG. 3 shows another example of a power source for use with an oxygen supply device according to the present invention.  
     [0070] In general, the oxygen supply device  10  according to the present invention can use a commercialized alternating-current (AC) voltage, e. g., AC 100V or 220V. That is, a controller  14 , and a pump or heater, which are provided in the oxygen generator  15  will be described later, are controlled by the controller  14 , and powered at AC 110V or 220V. For this purpose, the controller  14  in the oxygen generator  15  is configured to directly receive an external power through a power cable  83  and a connector  81   a  from an external power source such as an inverter  80 . The connector  81   a  is a well-known plug that can be plugged directly into an outlet (not shown) on a wall as shown in FIGS. 25A and 25B.  
     [0071] In FIG. 2, the oxygen supply device  10  is connected to a power supply generating direct-current (DC) power, in which the power supply is a cigarette jack port  82  in a vehicle.  
     [0072] Referring to FIG. 2, the oxygen generator  15  is connected to a cigarette jack port  82  via an inverter  80  to which the oxygen generator  15  is connected via the connector  81   a  and the power cable  83 , and the inverter  80  is connected to the cigarette jack port  82  via the power cable  83 . If the connector  81   a  is separated from the external inverter  80  in FIG. 2, the oxygen generator  15  can be removed from a vehicle and installed somewhere other than the vehicle.  
     [0073] The inverter is a well-known inverting device for inverting a DC 12V into an AC 110V or 220V. Here, the AC 110V or 220V is transferred to the controller  14 . Thus, the oxygen supply device  10  according to the present invention receives a voltage supplied from the cigarette jack port  82  and then operates.  
     [0074] In FIG. 2, the inverter  80  used for supplying a voltage to the oxygen generator  15  is installed outside of the oxygen generator  15 . However, in FIG. 3, the inverter  80  is installed within the oxygen generator  15 .  
     [0075] In particular, as shown in FIG. 3, the inverter  80  installed within the oxygen generator  15  is connected to the controller  14  in the oxygen generator  15 . In addition, the controller  14  can further include an externally extended power cable  83  and a connector  81   a  so as to receive AC power from an external power source.  
     [0076] Meanwhile, the cigarette jack port  82  and the inverter  80  are connected to each other via the power cable  83 . Thus, the DC voltage supplied from the cigarette jack port  82  is supplied to the inverter  80  in the oxygen generator  15  via the power cable  83  and then inverted into AC voltage by the inverter  80  to then be supplied to the controller  14 . The power cable  83  connected to the inverter  80  can be connected to or isolated from the external power source by a connector  81   b . The connector  81   b  is a well-known connection component.  
     [0077] If the connector  81   b  is separated from the external power source such as a cigarette jack port  82  in FIG. 3, the oxygen generator  15  can be removed from a vehicle and installed somewhere other than the vehicle.  
     [0078] In FIG. 3, the oxygen generator  15  of the oxygen supply device  10  possesses two connectors  81   a  and  81   b . The two connectors are alternatively used, such that one connector  81   a  is a plug fitted into an outlet in order to directly receive an external AC voltage, and the other connector  81   b  is a connector for receiving a DC voltage from the cigarette jack port  82 .  
     [0079]FIGS. 4A through 6B are schematic configurational diagrams showing various examples when each oxygen supply device according to the first and second embodiments of the present invention is applied to a vehicle.  
     [0080] In FIGS. 4A, 5A, and  6 A, an oxygen supply device having a power supply mode shown in FIG. 2 is shown respectively. In FIGS. 4B, 5B and  6 B, an oxygen supply device having a power supplying mode shown in FIG. 3 is shown respectively.  
     [0081] Referring to FIG. 4A, an oxygen supply device  10  according to a first embodiment of the present invention includes an oxygen generator  15   a  installed in a trunk of a vehicle V for supplying oxygen into the inside of the vehicle through an oxygen supply line  24 ; a control panel  12  connected to the oxygen generator  15   a  by a wire or wirelessly for controlling the oxygen generator  15   a ; a power supply for supplying a voltage from the cigarette jack port  82  to the oxygen generator  15   a ; and an oxygen concentration sensor  78  for sensing an indoor oxygen concentration.  
     [0082] The oxygen generator  15   a  in the oxygen supply device  10  has a basic operational mechanism, which receives outside air through an air inflow tube  16 , so that it passes through an oxygen separator  38  shown in FIG. 8 to be described later, and thus separates oxygen from the received air, and supplies the separated oxygen to a place requiring oxygen through an oxygen discharging tube  18 .  
     [0083] The position where the oxygen generator  15   a  is installed varies according to the type of vehicle. For example, for a freight vehicle, the oxygen generator  15   a  can be installed in a rear-side loading cabinet. In addition, the control panel  12  is positioned close to the driver&#39;s seat to allow a driver to easily manipulate it.  
     [0084] The oxygen generator  15   a  is connected to a cigarette jack port  82  through a power cable  83 , the inverter  80 , and a connector  81   a . Thus, the oxygen generator  15   a  receives an AC voltage inverted from the DC voltage by the inverter  80  and then operates.  
     [0085] Also, as will be described later, the components of the oxygen generator  15   a  are contained in a case  11 . Thus, if the connector  81   a  is separated from the inverter  80  and a connector  92  for connecting an oxygen discharging tube  18  to an oxygen supply line  24  is also separated from the oxygen supply line  24 , a user can take hold of a grip  58  of the case  11  and transfer the oxygen generator  15   a  from the trunk of the vehicle to another place after the oxygen generator  15   a  has been dismantled from the trunk.  
     [0086] The air inflow tube  16  is connected to pumps  36  and  48  in the case  11  to be described later, in order to take in outside air into the case  11 . Also, the oxygen discharging tube  18  is connected to the oxygen supply line  24  via the connector  92 , so that oxygen generated from the oxygen generator  15   a  is supplied to a desired place via the oxygen supply line  24 .  
     [0087] Also, an aromatic diffuser  86  and a discharged oxygen concentration sensor  131  are additionally provided along the oxygen discharging tube  18 . The aromatic diffuser  86  contains aromatic materials for generating various kinds of fragrances and is opened in a passage through which oxygen flows toward the oxygen supply line  24  to thereby aromatize the flowing oxygen that spreads throughout the indoor areas.  
     [0088] The discharged oxygen concentration sensor  131  senses the oxygen concentration of the oxygen discharged through the oxygen discharging tube  18  and transfers the sensed result to the control panel  12  to be described later. The discharged oxygen concentration sensor  131  is connected to the control panel  12  by a wire or wirelessly.  
     [0089] A nitrogen discharging tube  20  and a condensed water drainage tube  22  are further provided in the oxygen generator  15   a . The nitrogen discharging tube  20  is connected to an oxygen separator  38  to be described later, for outwardly discharging air (mostly nitrogen gas), which does not pass the oxygen separator  38 . Also, a condensed water drain tube  22  is connected to a condensed water trap  42  of FIG. 8 as shown in FIG. 8, for externally draining the condensed water generated during the generation of oxygen.  
     [0090] Meanwhile, the indoor oxygen concentration sensor  78  is a well-known oxygen concentration sensor for sensing indoor oxygen concentration and may be installed at a height near the driver&#39;s head, or positioned on a sun visor located in the upper-front position from a driver&#39;s seat.  
     [0091] The oxygen concentration sensor  78  is connected to the control panel  12  by a wire or wirelessly, so that a current indoor oxygen concentration can be displayed on a display window  70  of the control panel  12 . A plurality of oxygen concentration sensors  78  can be installed.  
     [0092] The control panel  12  includes a display  12   a  and a manipulator  12   b . The display  12   a  displays oxygen concentration values sensed by the oxygen concentration sensor  78  and the discharged oxygen concentration sensor  131 , and is connected to the manipulator  12   b  which indicates a desired oxygen concentration on the display  12   a  whenever desired oxygen concentration input buttons  72  and  73  are pressed on the manipulator  12   b . A liquid display device (LCD) can be applied as a display window  70  of the display  12   a.    
     [0093] The display window  70  displays the oxygen concentration values sensed by the oxygen concentration sensors  78  and  131  thereon, to thereby provide a reference for making a driver when controlling the controller  14  to increase or decrease the amount of oxygen produced.  
     [0094] In particular, an indoor oxygen concentration displayed on the display window  70  after being sensed by the oxygen concentration sensor  78  is indicated as a percentage. The oxygen percentage is obtained by calculating a formula, that is, a current indoor oxygen concentration divided by a driver&#39;s desired oxygen concentration multiplied by 100. Here, the driver&#39;s desired oxygen concentration is input in advance to the controller  14  through the desired oxygen concentration input buttons  72  and  73  on the manipulator  12   b.    
     [0095] Thus, in a case where a driver&#39;s desired indoor oxygen concentration is 20.9% and an indoor oxygen concentration sensed by the oxygen concentration sensor  78  is 20.0%, the oxygen percentage is 96% using the above forrnula, and thus, a figure of 96 is displayed on the display window  70 .  
     [0096] Likewise, in a case where an actual indoor oxygen concentration is 21.7%, a figure of a displayed oxygen concentration value becomes 104% which exceeds a figure of 100.  
     [0097] That is, a displayed figure exceeding a figure of 100 means that an actual oxygen concentration is higher than a driver&#39;s desired oxygen concentration. A displayed figure less than a figure of 100 means that an actual oxygen concentration is lower than a driver&#39;s desired oxygen concentration. As a result, the driver can easily recognize the current oxygen concentration to thereby make proper adjustments.  
     [0098] Although the manipulator  12   b  can be combined with the display  12   a  as shown in this embodiment, the display  12   a  and the manipulator  12   b  can also be formed separately.  
     [0099] The manipulator  12   b  is connected to a signal receiver  107  in the oxygen generator  15   a  of FIG. 1 by a wire or wirelessly, to thereby send a signal to the controller  14  control the amount of oxygen produced in the oxygen separator  38  and a condensed water drain valve  44  of FIG. 8 as well.  
     [0100] On the front surface of the manipulator  12   b  are provided a warning lamp  74 , a condensed water drainage button  76 , a set button  84 , and a reset button  85  in addition to the desired oxygen concentration input buttons  72  and  73 .  
     [0101] The desired oxygen concentration input buttons  72  and  73  are input buttons for inputting desired oxygen concentration values into the controller  14 . When the desired oxygen concentration input buttons  72  and  73  are pressed, a figure is displayed on the display window  70 , to thereby enable an operator such as a driver to increase or decrease the figure for a desired oxygen concentration.  
     [0102] Also, the set button  84  is a button for setting and storing a figure determined by the desired oxygen concentration input buttons  72  and  73 , so that the controller  14  stores the desired oxygen concentration. The reset button  85  is a button for changing the set figure. That is, after pressing the reset button  85 , an oxygen concentration of a desired figure can be set by increasing or decreasing a figure while pressing the desired oxygen concentration input buttons  72  and  73 .  
     [0103] A circuitry configuration including the desired oxygen concentration input buttons  72  and  73 , the set button  84  and the reset button  85  can be easily implemented by one skilled in the art with basic circuitry knowledge. Accordingly, a circuitry configuration providing an identical function can be modified in various forms.  
     [0104] The warning lamp  74  is a lamp for informing a driver of a time when condensed water contained in a condensed water trap  42  of FIG. 8 to be described later is to be drained. For example, when a level of the condensed water reaches electrodes  52  of FIG. 14, the warning lamp  74  is lit. All other times, the warning lamp  74  is not lit.  
     [0105] The condensed water drainage button  76  provided next to the warning lamp  74  is a button for opening a condensed water drainage valve  44  of FIG. 14 to be described later. As described above, the condensed water drainage valve  44  is a valve which stays closed when power is supplied from an external power source. Accordingly, when the condensed water drainage button  76  has been pressed, power supplied to the condensed water drainage valve  44  is interrupted. A circuitry configuration for interrupting power supplied to the condensed water drainage valve  44  when the condensed water drainage button  76  can be implemented by a person who has an ordinary skill in the art with basic circuitry knowledge.  
     [0106] As described above, the control panel  12  is installed near a driver when the oxygen supply device  10  is used in a vehicle, so that the driver can manipulate the control panel  12  conveniently. When the oxygen supply device  10  is used indoors as shown in FIGS. 25A and 25B, the position of the control panel  12  can be freely selected as far as the oxygen supply device can still be controlled.  
     [0107] The oxygen supply line  24  is a passage for supplying oxygen produced in the oxygen generator  15   a  to a place requiring oxygen. In this embodiment, the oxygen supply line  24  is installed adjacent to the ceiling above the driver&#39;s seat in the inside of a vehicle V. The oxygen supply line  24  is connected to the oxygen discharging tube  18  by the connector  92  but can be separated from the oxygen discharging tube  18  when necessary as described above.  
     [0108] The oxygen supply line  24  passes through the indoor ceiling so that one end of the oxygen supply line  24  is extended to the inside of a grill  26  provided in a surface in front of the driver&#39;s seat. Thus, the oxygen generated from the oxygen generator  15   a  is supplied indoors through the grill  26 . In this case, an air-conditioner or heater can be operated together with the oxygen supply device.  
     [0109] In addition, a second condensed water trap  121  is additionally installed on the oxygen supply line  24 . The second condensed water trap  121  is prepared for gathering condensed water which can be generated from oxygen passing through the oxygen supply line  24 . A basic function of the second condensed water trap  121  is the same as that of the typical condensed water trap.  
     [0110] The second condensed water trap  121  includes a sealing case  121   a  in which condensed water is collected. The oxygen supply line  24  is inserted into the sealing case  121   a  at a state where a certain portion of the oxygen supply line  24  has been cut off. The sealing case  121   a  is sealed by a sealing cap  121   b .  
     [0111] Accordingly, oxygen flowing through the oxygen supply line  24  passes through the sealing case  121   a . In this case, if condensed water is produced, the produced condensed water is collected in the sealing case  121   a  due to gravitational force.  
     [0112] Meanwhile, the second condensed water trap  121  can be installed at a place desired by the user. However, it is preferable that the second condensed water trap  121  is installed in the lower portion of a driver&#39;s seat so the driver can easily manage the condensed water.  
     [0113] The driver separates the sealing case  121   a  from the sealing cap  121   b  manually in order to empty the condensed water collected in the sealing case  121   a.    
     [0114]FIG. 4B shows an oxygen supply device employing a power supplying mode shown in FIG. 3.  
     [0115] Hereafter, the same reference numerals as those of FIG. 4A indicate the same members having the same functions as those of FIG. 4A. Thus, the detailed descriptions thereof will be omitted.  
     [0116] Referring to FIG. 4B, an inverter  80  is installed in a case  11 . The inverter  80  receives a DC voltage from a cigarette jack port  82  as shown in FIG. 3 and inverts the received DC voltage into an AC voltage. An oxygen generator  15   c  operates under the AC voltage. Here, a connector  81   a  for directly receiving an AC voltage from an external power source is not plugged into an outlet.  
     [0117]FIGS. 5A and 5B are schematic configurational diagrams showing other examples when each oxygen supply device according to the first and second embodiments of the present invention is applied to a vehicle.  
     [0118]FIG. 5A shows an oxygen supply device having a power supply mode shown in FIG. 2, and FIG. 5B shows an oxygen supply device having a power supply mode shown in FIG. 3.  
     [0119] Referring to FIGS. 5A and 5B, an oxygen supply line  28  is installed along an inner ceiling and includes a plurality of diffusion nozzles  30  for spraying oxygen downwards. The diffusion nozzles  30  are well-known nozzles for spraying oxygen flowing through an oxygen supply line  28  in a downward direction. The number of the diffusion nozzles  30  installed along the oxygen supply line  28  can be varied according to different design criteria.  
     [0120]FIGS. 6A and 6B are schematic configurational diagrams showing still other examples when each oxygen supply device according to the first and second embodiments of the present invention is applied to a vehicle.  
     [0121]FIG. 6A shows an oxygen supply device having a power supply mode shown in FIG. 2, and FIG. 6B shows an oxygen supply device having a power supply mode shown in FIG. 3.  
     [0122] Referring to FIGS. 6A and 6B, a control panel  12  is fitted onto a sun visor S. The function of the control panel  12  is the same as those of FIGS. 4A to  5 B.  
     [0123]FIG. 7A is a detailed diagram showing a control panel respectively shown in FIGS. 4A through 6B. FIG. 7B is a side view showing a control panel of FIGS. 4A through 6B which is installed on a sun visor.  
     [0124] As shown in FIG. 7A, an oxygen concentration sensor  78  is installed on the front surface of a manipulator  12   b . The basic function of the oxygen concentration sensor  78  is the same as those used in the oxygen supply devices shown in FIGS. 4A through 6B.  
     [0125] Referring back to FIGS. 6A and 6B, the oxygen supply line  113  for transferring oxygen produced indoors by each of the respective oxygen generators  15   a  and  15   c  is positioned near the ceiling indoors, and one end of the oxygen supply line  113  is extended toward a sun visor S. Next, the oxygen supply line  113  is connected to a flexible tube  96  through the control panel  12 .  
     [0126] The flexible tube  96  is a well-known tube which can be freely bent in any direction and then be maintained at the bent state. As shown in FIG. 7A, an oxygen spraying exit  94  is provided on one end of the flexible tube  96 .  
     [0127] A reference numeral  93  denotes a connector. The connector  93  is a connection unit for connecting and disconnecting the control panel  12  to and from the oxygen supply line  113 , respectively.  
     [0128]FIG. 7A is a schematic perspective view showing a control panel of FIGS. 6A and 6B, respectively.  
     [0129] As shown in FIG. 7A, a connection tube  98  is provided on the upper portion of the control panel  12 . The connection tube  98  is upwardly connected to the oxygen supply line  113  via the connector  93  and is connected to the flexible tube  96  through the control panel  12  downwards.  
     [0130] The connection tube  98  can be installed so as to pass through the control panel  12  unless the former obstructs the inner circuitry configuration of the latter. However, if the connection tube  98  obstructs the inner circuitry configuration of the control panel  12 , the connection tube  98  can be installed via a roundabout route of the control pane  12 .  
     [0131] The flexible tube  96  is a metallic tube which can be bent in any direction and maintain a bent state. The oxygen spraying exit  94  provided on the lower end of the flexible tube  96  is a well-known diffusion nozzle for spraying oxygen more widely.  
     [0132] In addition, an oxygen concentration sensor  78  is installed on the front surface of the control panel  12 . The oxygen concentration sensor  78  senses the oxygen concentration near a sun visor S and transfers the sensed result so as to be displayed on a display window  70  of a display  12   a . That is, an oxygen concentration value is displayed on the display window  70 .  
     [0133] Meanwhile, as shown in FIG. 7B, a clip  99  is provided on the rear portion of the control panel  12  so the control panel  12  can be fixed to the sun visor S. The clip  99  provides an elastic force in the direction of the arrow f and presses the sun visor when the control panel  12  is fitted on the sun visor S, to thereby temporarily fix the control panel  12  to the sun visor S.  
     [0134]FIGS. 8 through 13 are schematic diagrams for explaining the inner structure of an oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention. In FIGS. 8 through 13, an inverter  80  is installed in an oxygen supply device  15   c  which has already been described with reference to FIG. 3. The FIGS. 8 through 13 oxygen generators are same as that of FIG. 2, if the inverter  80  is excluded from the respective oxygen generators of FIGS. 8 through 13.  
     [0135] Referring to FIG. 8, an oxygen generator  15   c  in an oxygen supply device  10  according to a second embodiment of the present invention is installed in a case  11 , which has an air inflow inlet  16  and an oxygen discharging outlet  18 , for providing an inner space for installing each component therein, in which the oxygen generator includes a first pump  36  for receiving external air through the air inflow tube  16 , an oxygen separator  38  connected to the first pump  36  through which air discharged from the first pump  36  passes and oxygen is separated and generated from the air so that a gas other than oxygen can be discharged through a nitrogen discharging tube  20 , a second pump  40  connected to the oxygen separator  38 , for transferring oxygen separated by the oxygen separator, a condensed water trap  42 , which is connected to the second pump  40 , including a condensed water drainage valve  44  positioned on the lower portion of the condensed water trap  42  for separating the condensed water generated during oxygen generation and collecting the same therein, and a controller  14  for controlling the pumps  36  and  40  and the condensed water trap  42 .  
     [0136] The condensed water trap  42  is an embodiment of a wet oxygen prevention unit for preventing water drops from being discharged through the oxygen discharging tube  18 . Instead of the condensed water trap  42 , a heater, an evaporator, and so on can be adopted along the air inlet tube or the oxygen outlet tube.  
     [0137] The first and second pumps  36  and  40  can each adopt a well-known centrifugal pump.  
     [0138] The controller  14  receives an AC power through an inverter  80  or a connector  81   a  and then controls operations of the pumps  36  and  40  and the condensed water drainage valve  44 . Meanwhile, even in the case that the inverter  80  is not installed in the oxygen generator  15   c , an AC power is supplied directly through the connector  81   a  as shown in FIG. 2.  
     [0139] Meanwhile, the oxygen separated from the oxygen separator  38  generates condensed water due to the variation in temperature and pressure when passing through the oxygen discharging tube.  
     [0140] The condensed water trap  42  collects the condensed water generated as described above and dispenses the collected condensed water. The detailed structure will be described with reference to FIG. 14. The condensed water drainage valve  44  provided on the lower portion of the condensed water trap  42  is a well-known solenoid valve which is opened and closed under the control of the controller  14 .  
     [0141] The electric power supplied to the condensed water drainage valve  44  is interrupted by pressing the condensed water drainage button  76  provided on the control panel  12 . That is, if the condensed water drainage button  76  is pressed, the electric power supplied to the condensed water drainage valve  44  under the control of the controller  14  is interrupted to thereby open the condensed water drainage valve  44 . If the condensed water drainage button  76  is not pressed, the electric power is continuously supplied to the condensed water drainage valve  44  to thereby close the condensed water drainage valve  44 .  
     [0142] In particular, when the engine of a vehicle stops, no electric power is supplied from a cigarette jack port  82 , and thus no electricity is supplied to the condensed water drainage valve  44 . The condensed water drainage valve  44  is automatically opened.  
     [0143] The oxygen separator  38  is a hollow thread film-type of an oxygen separator having a hollow thread film therein, or a flat film-type of an oxygen separator having a flat film therein. The hollow thread film-type oxygen separator or flat film-type oxygen separator is a well-known oxygen separator. When air is taken in and passes through the oxygen separator, oxygen is separated from the air that has been taken in. A gas other than oxygen is discharged into the outer air through a nitrogen discharging tube  20 . Here, although the gas other than oxygen is not pure nitrogen, a majority of the gas is occupied by nitrogen. In this embodiment, the oxygen separated gas discharging tube is called a nitrogen discharging tube.  
     [0144] The oxygen supply device  10  according to an embodiment of the present invention has a comparatively simple operating mechanism in which air intake through the air inlet tube  16  passes through the oxygen separator  38  to produce oxygen, and the oxygen produced by the oxygen separator  38  passes through the condensed water trap  42  to remove water drops from the oxygen discharged through the oxygen discharging tube  18 .  
     [0145] Meanwhile, since the controller  14  controls the first and second pumps  36  and  40 , a pumping capacity of each pump can be controlled by the controller  14  to control the amount of oxygen produced.  
     [0146] Also, an aromatic diffuser  86  is provided on the end of the oxygen discharging tube  18 .  
     [0147]FIG. 9 is a schematic diagram for explaining the inner structure of another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 8 oxygen generator.  
     [0148] Referring to FIG. 9, an ultraviolet sterilizer  46  is additionally provided between the first pump  36  and the oxygen separator  38 . The ultraviolet sterilizer  46  has at least one lamp emitting an ultraviolet ray having a sterilizing capability. Accordingly, the ultraviolet sterilizer  46  sterilizes various types of bacteria in the air flowing from the first pump  36  to the oxygen separator  38 , enabling fresher oxygen to be discharged. The ultraviolet sterilizer  46  is also controlled by the controller  14 .  
     [0149]FIG. 10 is a schematic diagram for explaining the inner structure of still another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 8 oxygen generator.  
     [0150] Referring to FIG. 10, an ultraviolet sterilizer  46  is installed between the condensed water trap  42  and the oxygen discharging tube  18 . The ultraviolet sterilizer  46  is the same as that of FIG. 9, except that it sterilizes bacteria in the dried oxygen that has passed through the condensed water trap  42 .  
     [0151]FIG. 11 is a schematic diagram explaining the inner structure of yet another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 8 oxygen generator.  
     [0152] Referring to FIG. 11, a piston pump  48  is applied as a unit for intaking air from outside of the case  11  toward the oxygen separator  38 . The piston pump  48  is a well-known pump having a cylinder and a piston reciprocating in the cylinder. The outside air through the air inlet tube  16  and is compressed and exhaled into the oxygen separator  38 , to thereby enable the oxygen separator  38  to produce oxygen.  
     [0153]FIG. 12 is a schematic diagram explaining the inner structure of another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 11 oxygen generator.  
     [0154] Referring to FIG. 12, an ultraviolet sterilizer  46  is provided between the piston pump  48  and the oxygen separator  38 . The ultraviolet sterilizer  46  sterilizes various germs in the air when the air that has been taken in passes through the oxygen separator  38  from the piston pump  48 , thereby enabling the oxygen separator  38  to produce fresher oxygen.  
     [0155]FIG. 13 is a schematic diagram explaining the inner structure of still another oxygen generator in each of the oxygen supply devices according to the first and second embodiments of the present invention, differing from the FIG. 11 oxygen generator.  
     [0156] Referring to FIG. 13, an ultraviolet sterilizer  46  is installed between the condensed water trap  42  and the oxygen discharging tube  18 . The dried oxygen that has passed through the condensed water trap  42  passes through the ultraviolet sterilizer  46  to then be sterilized into fresher oxygen and supplied to a place requiring oxygen.  
     [0157]FIG. 14 is a schematic diagram explaining the structure of a condensed water trap installed in the oxygen supply device respectively shown in FIGS.  8  to  13 .  
     [0158] Referring to FIG. 14, the condensed water trap  42  includes a container  60  providing a space to temporarily store condensed water therein, electrode supporters  54  installed opposite to one another on the inner wall surface of the container  60 , and electrodes  52  installed opposite to one another in the electrode supporters  54  and at the identical height from the bottom of the container  60 .  
     [0159] Also, an inlet tube  64  and an exit tube  66  are provided on the upper portion of the container  60 . The inlet tube  64  is connected to the oxygen separator  38 , for introducing oxygen into the container  60 , and the exit tube  66  induces the dried oxygen that has passed through the container  60  toward the oxygen discharging tube  18 .  
     [0160] Meanwhile, the electrodes  52  are well-known sensing units for detecting the level of condensed water collected in the container  60 . As soon as the level of the condensed water collected in the container  60  reaches the height of the electrodes  52 , the electrodes  52  are connected in circuitry by the water, which is conductive, thereby detecting whether the water level has reached the height of the electrodes  52 .  
     [0161] The sensed result of the electrodes  52  is monitored by a warning lamp  74  on the control panel  12  via a cable  62 . As a result, a driver can open the condensed water drainage valve  44  to drain the condensed water. In order to drain the condensed water, the condensed water drainage button  76  provided on the manipulator  12  is pressed to interrupt an electric power supplied to the condensed water trap  42 , as described above.  
     [0162] The condensed water drainage valve  44  provided on the lower portion of the container  60  is a valve for draining the condensed water collected in the container  60  and operates under the control of the controller  14 . However, the condensed water drainage valve  44  can be designed to operate manually.  
     [0163] The condensed water drainage valve  44  is a well-known two-port-two-position shift valve which is designed to be closed when electric power is supplied from an external power source, thereby preventing the condensed water from draining, and opened when electric power is not supplied from the external power source, thereby enabling the condensed water to be drained.  
     [0164] Thus, when a driver manipulates the control panel  12  to interrupt electric power supplied to the condensed water drainage valve  44 , the condensed water drainage valve  44  is opened by an elastic force of a spring  68  to drain the condensed water. In particular, when the engine of a vehicle stops as described above, the electric power is not supplied to the condensed water drainage valve  44 . As a result, although a driver may forgot to empty the condensed water, the condensed water is automatically drained when the engine of the vehicle stops.  
     [0165]FIGS. 15A and 15B are schematic configurational diagrams showing examples when each oxygen supply device according to the third and fourth embodiments of the present invention is applied to a vehicle.  
     [0166]FIG. 15A shows an oxygen supply device having a power supply mode shown in FIG. 2, and FIG. 15B shows an oxygen supply device having a power supply mode shown in FIG. 3. In addition, as will be described later, since condensed water is not produced in the oxygen generators  15   b  and  15   d , a condensed water drainage button, a warning lamp, or a condensed water drainage tube are not provided therein.  
     [0167] Referring to FIG. 15A, a display window  70  is provided on a display  12   a  in a control panel  12 . desired oxygen concentration input buttons  72  and  73 , a set button  84 , a reset button  85 , and a heater on/off button  90  are provided on a manipulator  13   b . In particular, the heater on/off button  90  provided on the manipulator  13   b  is a button for determining whether a heater provided in a case  11  of each of oxygen generators  15   b  and  15   d  is turned on or off.  
     [0168]FIGS. 16A and 16B are schematic configurational diagrams showing other examples when each oxygen supply device according to the third and fourth embodiments of the present invention is applied to a vehicle. FIG. 16A shows an oxygen supply device having a power supply mode shown in FIG. 2, and FIG. 16B shows an oxygen supply device having a power supply mode shown in FIG. 3.  
     [0169]FIGS. 17A and 17B are schematic configurational diagrams showing still other examples when each oxygen supply device according to the third and fourth embodiments of the present invention is applied to a vehicle. FIG. 17A shows an oxygen supply device having a power supply mode shown in FIG. 2, and FIG. 17B shows an oxygen supply device having a power supply mode shown in FIG. 3.  
     [0170]FIG. 18 is a detailed diagram showing a control panel respectively shown in FIGS. 15A to  17 B.  
     [0171] Referring to FIG. 18, a control panel  12  includes a display  12   a  and a manipulator  13   b . A heater on/off button  90  is provided on the manipulator  13   b . The heater on/off button  90  to be described later with reference to FIGS. 19 through 24 is a manipulation button for turning a heater on or off.  
     [0172]FIG. 19 is a schematic diagram explaining the inner structure of an oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention.  
     [0173] An oxygen supply device according to these embodiments of the present invention is based on a concept which is capable of preventing condensed water from being produced if air is heated prior to generating oxygen even if a pressure of oxygen is varied during an oxygen separating process.  
     [0174] Also, a power supply mode supplied to the oxygen generator  15   d  adopts a mode described with reference to FIG. 3. Except for an inverter  80 , the structure of the FIG. 19 oxygen generator is the same as that of the oxygen generator shown in FIG. 2.  
     [0175] Referring to FIG. 19, a condensed water trap  42  does not exist in the oxygen generator  15   d  of the oxygen supply device according to a fourth embodiment of the present invention. Instead, a heater  88  is provided in the oxygen generator  15   d . The heater  88 , which is controlled by the controller  14 , and heats air moving toward the oxygen separator  38 , to thereby prevent condensed water from being produced due to a variation in pressure and temperature occurring when air passes through the oxygen separator  38 .  
     [0176] The oxygen separated by the oxygen separator  38  is transferred directly to the oxygen discharging tube  18  via the second pump  40  and then transferred to a place requiring oxygen via an aromatic diffuser  86 . Here, the oxygen separated air is discharged to the atmosphere via a nitrogen discharging tube  20 .  
     [0177]FIG. 20 is a schematic diagram explaining the inner structure of still another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator.  
     [0178] Referring to FIG. 20, an ultraviolet sterilizer  46  is provided between a first pump  36  and a heater  88 .  
     [0179]FIG. 21 is a schematic diagram explaining the inner structure of yet another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator.  
     [0180] Referring to FIG. 21, an ultraviolet sterilizer  46  is provided between a second pump  40  and an oxygen discharging tube  18 . The ultraviolet sterilizer  46  sterilizes bacteria from the oxygen separated from the air, so that sterilized oxygen is discharged outside of the case  11  via the oxygen discharging tube  18 .  
     [0181]FIG. 22 is a schematic diagram explaining the inner structure of another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator.  
     [0182] Referring to FIG. 22, a piston pump  48  is installed in order to move the air from outside of a case  11  toward an oxygen separator  38 . A heater  88  is provided between the piston pump  48  and the oxygen separator  38 .  
     [0183]FIG. 23 is a schematic diagram explaining the inner structure of still another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator.  
     [0184] Referring to FIG. 23, an ultraviolet sterilizer  46  is additionally provided between the piston pump  48  and the heater  88  in the oxygen generator  15   d  shown in FIG. 22.  
     [0185]FIG. 24 is a schematic diagram explaining the inner structure of yet another oxygen generator in each of the oxygen supply devices according to the third and fourth embodiments of the present invention, differing from the FIG. 19 oxygen generator.  
     [0186] Referring to FIG. 24, an ultraviolet sterilizer  46  is additionally provided between the oxygen separator  38  and the oxygen discharging tube  18  in the oxygen generator  15   d  shown in FIG. 22.  
     [0187]FIGS. 25A and 25B are schematic configurational diagrams showing examples when each oxygen supply device according to first through fourth embodiments of the present invention is applied indoors, other than a vehicle.  
     [0188]FIG. 25A shows an oxygen supply device having a power supply mode shown in FIG. 2, and FIG. 25B shows an oxygen supply device having a power supply mode shown in FIG. 3.  
     [0189] Referring to FIGS. 25A and 25B, an oxygen discharging unit  109  is fixed to any one place on a wall inside a house H. The oxygen discharging unit  109  discharges oxygen and can be modified in various shapes in order to discharge oxygen.  
     [0190] An oxygen discharging tube  18  of each of oxygen generators  15   a  and  15   b  is connected to an oxygen supply line  115  via a connector  92 . The oxygen generated from each of the oxygen generators  15   a  and  15   b  flows upwards through the oxygen supply line  115  and is sprayed from an oxygen discharging unit  109 .  
     [0191] In addition, an oxygen concentration sensed by a discharged oxygen concentration sensor  131  provided in the oxygen discharging tube  18  is displayed on a display via a control panel  12 .  
     [0192] A connector  81   a  which provides electric power to the control panel  12  is connected to an outlet (not shown) mounted on a wall, so that AC power is supplied directly to the control panel  12 .  
     [0193] In particular, a connector  81  b which applies DC power to an inverter  80  provided in each of the oxygen generators  15   c  and  15   d  shown in FIG. 25B is not connected to any one outlet, that is, it is in a standby state.  
     [0194] Also, a control panel  12  and an oxygen concentration sensor  78  for sensing an indoor oxygen concentration are provided on another wall indoors. The control panel  12  can be hung on a wall via a well-known hookup unit. In particular, it is preferable that the control panel  12  is positioned at a user&#39;s eye level to thereby provide a user with ease recognizing a displayed result with the naked eye. Also, the oxygen concentration sensor  78  is preferably positioned at a user&#39;s eye level.  
     [0195]FIGS. 26A and 26B are detailed diagrams showing another control panel which can be applied to an oxygen supply device of the present invention. The control panel shown in FIGS. 26A or  26 B has a simpler configuration, and provides a simpler function than that shown in FIGS. 7A or  18 .  
     [0196] As shown in FIGS. 26A and 26B, a display window  70  is provided at the center on the front surface of a control panel  123 . A power on/off button  125  is positioned on the left-hand side of the display window  70 . Also, a calibration button  127  is provided on the right-hand side of the display window  70 .  
     [0197] The power on/off button  125  is a general power on/off button for turning a controller  14  on or off. Also, the calibration button  127  performs a correction function matching a desired oxygen concentration stored in the controller  14  with a reference oxygen concentration. Here, the reference oxygen concentration is an oxygen concentration that can theoretically provide users with the most comfort, and is an oxygen concentration stored in the controller  14 , and the desired oxygen concentration is a user&#39;s desired oxygen concentration which is newly input into the controller  14  when an oxygen supply device is in use.  
     [0198] The reference oxygen concentration is an invariable value stored in the RAM of a computer, and the desired oxygen concentration is a user&#39;s set value so that an oxygen supply device produces oxygen of the reference oxygen concentration.  
     [0199] Thus, the desired oxygen concentration and the reference oxygen concentration are initially the same. However, a desired oxygen concentration can differ greatly from a reference oxygen concentration due to a mechanical defect or other reasons when the oxygen supply device is used for an extended period of time.  
     [0200] Referring to FIG. 26B, an oxygen concentration sensor  78  is provided on the rear surface of a control panel  123 . The oxygen concentration sensor  78  senses an indoor oxygen concentration and transfers the same to a display window  70  so as to be displayed thereon.  
     [0201] As described above, the present invention has been described with respect to the particularly preferred embodiments, but the present invention is not limited in the above-described embodiments. It is apparent to one of ordinary skill in the art that there are many variations and modifications that can be made within the scope of the appended claims without departing from the spirit of the present invention.