Abstract:
In a circuit configuration provided in a vehicle, a first circuit is directly connected to an electric junction box to supply a notification signal indicating a condition of a part of the vehicle. A second circuit is adapted to transmit the notification signal. A first lamp module is disposed at a first part of the vehicle, and provided with a switch, and a junction circuit at which the first circuit and the second circuit are connected or disconnected in accordance with a state of the switch. A second lamp module is disposed at a second part of the vehicle and connected to the first lamp module via the second circuit. A light emitter which emits light when the notification signal is supplied thereto is provided in each of the first lamp module and the second lamp module.

Description:
BACKGROUND OF THE INVENTION 
   The present invention is related to a connecting circuit for lamp modules for various sorts of lamps for illuminating, for example, the interiors of vehicles. Particularly, the present invention is related to a connecting circuit capable of canceling the cooperative illumination function. 
   Nowadays, a vehicle is provided with a map lamp on a front area of an interior ceiling thereof, a dome lamp at a center area of the interior ceiling, and a rear reading lamp on a rear area of the interior ceiling. The map lamp is used in such a case that a driver of the vehicle reads maps. The dome lamp is used when the entire interior is illuminated. The rear reading lamp is used in a case that a passenger of a rear seat reads magazines. 
   The respective lamps, more specifically, map lamps installed on the side of driver&#39;s seat emits light so as to notify such a condition that a door of the vehicle is opened and/or is not completely closed. In other words, the courtesy lamp of the door and the map lamp emit light in a cooperating manner. 
   However, when the map lamp emits light every time the door is opened/closed, some car drivers may have bother feelings. Under such a circumstance, a cancel switch is provided with a map lamp. In the case that this cancel switch is activated, this map lamp and a courtesy lamp are placed in a non-cooperating mode, so that the map lamp does not emit light every time a door is opened/closed. That is, this map lamp is used only for the purpose of the map lamp. 
     FIG. 5  shows a connecting circuit provided with such a configuration. 
   A junction box  41  is connected to a power supply circuit (indicated by symbol “B”) connected with a battery, a signal circuit  47  connected with a courtesy lamp, and a grounding circuit (indicated by symbol “G”)  48  connected with a ground. The signal circuit  47  is indicated by symbol “CTY”, and will be referred to as a “courtesy circuit” or “notification signal circuit” hereinafter. The respective circuits  46  to  48  are connected via a junction connector  42  to a map lamp  43 , a dome lamp  44 , and a rear reading lamp  45  in a branching connection manner. 
   Two light emitters  49  are series-connected in the map lamp  43 , a cancel switch  50  is arranged between the two light emitters  49 , and this cancel switch  50  is slidable in the right/left directions in this figure so as to activate or deactivate a courtesy circuit  52 . By sliding the switch  54  in the right side of this figure, the light emitter  49  is connected to the courtesy circuit  52  to validate the condition of the courtesy circuit  52 . By sliding the switch  54  to the left side in this figure, the light emitter  49  is turned on irrespective of the condition of the switch  50  (the courtesy circuit  52 ). 
   In the dome lamp  44 , one end of a light emitter  55  is connected to a power supply circuit  56 , and the other end of the light emitter  55  is selectably connected to a courtesy circuit  57  or a grounding circuit  58  via a switch  59 . By sliding the switch  59  in the right side of this figure, the light emitter  55  is connected to the courtesy circuit  57  to validate the condition of the courtesy circuit  52 . By sliding the switch  59  to the left side in this figure, the light emitter  55  is turned on irrespective of the condition of the switch  50  (the courtesy circuit  52 ). 
   In the rear reading lamp  45 , one end of a light emitter  60  is connected to a power supply circuit  61 , and the other end of the light emitter  60  is selectably connected to a courtesy circuit  62  or a grounding circuit  63  via a switch  64 . By sliding the switch  64  in the right side of this figure, the light emitter  60  is connected to the courtesy circuit  62  to validate the condition of the courtesy circuit  52 . By sliding the switch  64  to the left side in this figure, the light emitter  60  is turned on irrespective of the condition of the switch  50  (the courtesy circuit  52 ). 
   As explained above, the cooperations between the respective lamps  43  to  45  and the respective courtesy circuits  52 ,  57 ,  62  can be canceled. The map lamp  43 , the dome lamp  44 , and the rear reading lamps  45  are constructed as lamp modules, respectively. 
   However, in the above configuration, since the circuits derived from the junction box  41  are wired via the junction connector  42  to the respective lamp modules  43  to  45 , the following problems occur. That is, the circuit construction becomes huge and complex, is manufactured in high cost, and also, requires a large number of steps when these circuits are distributed to vehicles. Furthermore, a large number of circuit distribution spaces are required. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the invention to provide a simple circuit configuration for connecting lamp modules with the canceling function for the cooperative illumination. 
   In order to achieve the above object, according to the invention, there is provided a circuit configuration provided in a vehicle, comprising: 
   an electric junction box; 
   a first circuit, directly connected to the electric junction box to supply a notification signal indicating a condition of a part of the vehicle; 
   a second circuit, adapted to transmit the notification signal; 
   a first lamp module, disposed at a first part of the vehicle, comprising:
         a switch; and   a junction circuit, at which the first circuit and the second circuit are connected or disconnected in accordance with a state of the switch; and       

   a second lamp module, disposed at a second part of the vehicle and connected to the first lamp module via the second circuit, 
   wherein a light emitter which emits light when the notification signal is supplied thereto is provided in each of the first lamp module and the second lamp module. 
   With such a configuration, since the junction circuit acts the same role as the conventional junction connector, the circuit construction can be made simple, and compact. The transmission of the notification signal supplied from the electric junction box to the second circuit can be interrupted by the switch. Here, the light emitters provided in the respective lamp modules are deactivated. Therefore, the lamp module connecting circuit can be easily and firmly installed in the narrow space of the vehicle with low costs. 
   Preferably, the circuit configuration further comprises a third lamp module, disposed at a third part of the vehicle and connected to the first lamp module via the second circuit. A light emitter which emits light when the notification signal is supplied thereto is provided in the third lamp module. 
   With such a configuration, all of the light emitters in the first, second and third lamp modules are deactivated by the operation of the switch. Here, the third lamp module may be series-connected to the first lamp module or the second lamp module. 
   Preferably, the circuit configuration further comprises a third lamp module, disposed at a third part of the vehicle and connected to the first lamp module via the first circuit. A light emitter which emits light when the notification signal is supplied thereto is provided in the third lamp module. 
   With such a configuration, the light emitters in the first and second lamp modules are deactivated by the operation of the switch. Here, the third lamp module may be series-connected to the first lamp module or the electric junction box. 
   According to the invention, there is also provided a circuit configuration provided in a vehicle, comprising: 
   an electric junction box; 
   a first circuit, directly connected to the electric junction box to supply a notification signal indicating a condition of a part of the vehicle; 
   a second circuit, adapted to transmit the notification signal; 
   a first lamp module, disposed at a first part of the vehicle, comprising:
         a switch; and   a junction circuit, at which the first circuit and the second circuit are connected or disconnected in accordance with a state of the switch; and       

   a second lamp module, disposed at a second part of the vehicle and connected to the electric junction box via the first circuit, 
   wherein a light emitter which emits light when the notification signal is supplied thereto is provided in each of the first lamp module and the second lamp module. 
   Preferably, the circuit configuration further comprises a third lamp module, disposed at a third part of the vehicle and connected to the electric junction box via the first circuit. A light emitter which emits light when the notification signal is supplied thereto is provided in the third lamp module. 
   With such a configuration, only the light emitter in the first lamp module is deactivated by the operation of the switch. Here, the third lamp module may be series-connected to the second lamp module or the electric junction box. 
   In the above cases, the first lamp module may be a map lamp module, one of the second lamp module and the third lamp module may be a dome lamp module, the other one of the second lamp module and the third lamp module may be a rear reading lamp module, and the notification signal may indicates whether a courtesy lamp is activated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein: 
       FIG. 1  is a circuit diagram showing a connecting circuit according to a first embodiment of the present invention; 
       FIG. 2  is a circuit diagram showing a connecting circuit according to a second embodiment of the present invention; 
       FIG. 3  is a circuit diagram showing a connecting circuit according to a third embodiment of the present invention; 
       FIG. 4  is a circuit diagram showing a connecting circuit according to a fourth embodiment of the present invention; and 
       FIG. 5  is a circuit diagram showing a related-art connecting circuit. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Preferred embodiments of the invention will be described below in detail with reference to the accompanying drawings. 
   As shown in  FIG. 1 , a circuit configuration according to a first embodiment comprises a junction box  1 , a map lamp (first lamp module)  2 , a dome lamp (second lamp module)  3  and a rear reading lamp (third lamp module)  4 . 
   In this embodiment, a junction circuit  5  having a function of a junction connector is provided with the map lamp  2 . A cancel switch  6  is provided in this junction circuit  5 . In other words, a cancel switch circuit may also have the function of junction circuit. The junction circuit  5  is arranged by four sets of bus bars  7  to  10 . 
   The junction circuit  5  is connected to main circuits  11  to  13 , which correspond to main wire harnesses derived from the junction box  1 . The main circuits are constituted by three lines of a power supply circuit  11 , a courtesy lamp circuit (notification signal circuit)  12 , and a grounding circuit  13 . The courtesy lamp circuit (will be referred to as “courtesy circuit” hereinafter)  12  corresponds to a circuit for sending ON/OFF signals of a courtesy lamp of a vehicle. 
   The power supply circuit  11  derived from the junction box  1  is directly connected via the junction circuit  7  to the power supply circuit  14  of the map lamp  2 , the courtesy circuit  12  is connected from a junction circuit  8  via both a cancel switch  6  and a short junction circuit  9  to a courtesy circuit (notification signal circuit)  15  of the map lamp  2 , and also, the grounding circuit  13  is directly connected to a grounding circuit  16  of the map lamp  2 . A right contact  17  of the cancel switch  6  is connected to the short junction circuit  9  for a courtesy purpose; a center contact  18  of this cancel switch  6  is connected to the long junction circuit  8  for a courtesy purpose; and a left contact  19  of this cancel switch  6  constitutes a dead contact which is not connected to any circuit. The respective lamps  2  to  4  can emit light at the same time in response to courtesy signals in an cooperating mode. 
   When the cancel switch  6  is slid along a left direction in  FIG. 1 , the courtesy circuit  15  is deactivated, so that the courtesy signal is not transferred to all of these lamps  2  to  4 . In other words, the courtesy signal is canceled in all of the lamps  2  to  4 , so that none of these lamps  2  to  4  emit light in cooperating manner as courtesy lamps. This is because certain car drivers have such intentions that any of these lamps  2  to  4  are not wanted to be operated in the cooperating mode. It should be understood that all of switches shown in this drawing are such slide switches which are slid along the right/left directions, as indicated by arrows. 
   While light emitters  20  are arranged in both sides of the cancel switch  6  one by one, one electrode circuit  21  of each of the light emitters  20  is directly connected to the power supply circuit  14  in a series connecting manner, whereas the other electrode circuit  22  is connected via switches  23  to the courtesy circuit  15 . When each of the switches  23  is slide-operated along the left direction in this figure, the other electrode circuit  22  of each of the light emitters  20  is connected to the grounding circuit  16 , so that the light emitter  20  can emit light irrespective of the cancel switch  6 . It is preferable that electrode circuits and connecting circuits, which are indicated by dashed lines in this drawing, are constructed of bus bars. 
   The three circuits of the map lamp  2 , namely, the power supply circuit  14 , the courtesy circuit  15 , and the grounding circuit  16  are extended via the center dome lamp  3  up to the rear reading lamp  4  by using wiring lines. The circuits shown in these chain lines are operated as sub-wire harnesses, and are preferably constituted by a flat cable. 
   In the dome lamp  3 , one electrode circuit  25  of a light emitter  24  is directly connected to the power supply circuit  14 , and the other electrode circuit  26  of this light emitter  24  is connected via a switch  27  to the courtesy circuit  15 , so that the light emitter  24  can emit light in response to a courtesy signal in the cooperating manner. When the switch  27  is slid along the left direction in this drawing, the other electrode circuit  26  is connected to the grounding circuit  16 , so that the light emitter  24  can emit light irrespective of the cancel switch  6 . 
   Similar to the map lamp  2 , the rear reading lamp  4  contains two light emitters  28 , and both a circuit arrangement and operations of this rear reading lamp  4  are similar to those of the above-described map lamp  2 . In other words, under the connection condition of the switch  29  shown in  FIG. 1 , the light emitters  28  emits light in the cooperating manner with the courtesy lamp, whereas when a switch  29  is slide in the left direction, the light emitters  28  emits light irrespective of the courtesy lamp (namely, rear reading lamp  4  can be used). 
   In the first embodiment, since the cancel switch circuit also serves as the junction circuit  5 , the conventional junction connector is no longer required, so that the circuit arrangement can be made simple, the space required to distribute the circuit can be reduced, and also, the cooperations between the courtesy lamps and all of the lamps  2  to  4  can be canceled by the cancel switch  6 . 
     FIG. 2  shows a circuit configuration according to a second embodiment of the invention. Components similar to those in the first embodiment will be designated by the same reference numerals and the repetitive explanation for those will be omitted. 
   In this embodiment, main circuits  11  to  13  derived from the junction box  1  are connected to a junction circuit (cancel circuit)  5 , and also, are connected to the dome lamp  3  and the rear reading lamp  4  in series connection manner, so that only the map lamp  2  is independently operated, and only the cooperation of a courtesy circuit (notification signal circuit)  15  of this map lamp  2  can be canceled. 
   The three lines of the main circuits (namely, power supply circuit  11 , courtesy circuit  12 , and grounding circuit  13 ) are extended up to the rear reading lamp  4  via the dome lamp  2 . 
   That is, as to circuit arraignments in the dome lamp  3  and the rear reading lamp  4 , only the sub-circuits  14  to  16  of  FIG. 1  are merely changed into the main circuits  11  to  13 , and other circuit arrangements thereof are similar to those of  FIG. 1 . 
   Since the cancel switch circuit also serves as the junction circuit  5 , the conventional junction connector is no longer required, so that the circuit arrangement can be made simple, and the space required to distribute the circuit can be reduced. Since the cancel switch  6  of the map lamp  2  is operated, while only the map lamp  2  is not operated with the courtesy circuit  12  in the cooperating manner, even in such a case that the courtesy signal is activated, the light emitters  20  of the map lamp  2  cannot emit light. Then, other lamps than the map lamp  2 , namely, both the dome lamp  3  and the rear reading lamp  4  are always operated with the courtesy circuit  12  in the cooperating manner, so that these dome lamp  3  and rear reading lamp  4  can simultaneously emit light when the courtesy lamp emits light. It is apparent that in both the dome lamp  3  and the rear reading lamp  4 , each of the light emitters  24  and  28  can independently emit light by sliding the switch  27  and the switch  29  in the left direction. 
     FIG. 3  shows a circuit configuration according to a third embodiment of the invention. Components similar to those in the first embodiment will be designated by the same reference numerals and the repetitive explanation for those will be omitted. 
   In this embodiment, main circuits  11  to  13  derived from the junction box  1  are connected to a junction circuit (cancel circuit)  5 , and also, are connected to the rear reading lamp  4  in series connection manner. 
   Furthermore, sub-circuits  14  to  16  of the map lamp  2  are extended up to the dome lamp  3  as sub-circuits  14  to  16  of the dome lamp  3 , so that the cooperation of a courtesy circuit  15  in the map lamp  2  and the dome lamp  3  can be simultaneously canceled. 
   Specifically, when a cancel switch  6  of the map lamp  2  is slid to the left in this figure, the courtesy circuit  15  is interrupted, so that both the map lamp  2  and the dome lamp  3  are operated in a non-cooperating manner with respect to the courtesy circuit  12 , and thus, even when a courtesy lamp emits light, the respective light emitters  20  and  24  of the map lamp  2  and the dome lamp  3  do not emit light. 
   Circuit arrangements of both the map lamp  2  and the dome lamp  3  are the same as those shown in the first embodiment. The sub-circuits  14  to  16  continued from the map lamp  2  are terminated in the dome lamp  3 , so that the map lamp  2  is not directly connected to the rear reading lamp  4 . The main circuits  11  to  13  are directly connected to the rear reading lamp  4 . 
   Therefore, in accordance with the operation of the cancel switch  6 , the cooperation of the courtesy circuit  15  in the map lamp  2  and the dome lamp  3  can be canceled while the cooperation of the rear reading lamp  4  is maintained irrespective of the operation of the cancel switch  6 . 
     FIG. 4  shows a circuit configuration according to a fourth embodiment of the invention. Components similar to those in the first embodiment will be designated by the same reference numerals and the repetitive explanation for those will be omitted. 
   In this embodiment, main circuits  11  to  13  derived from the junction box  1  are connected to a junction circuit (cancel circuit)  5 , and also, are connected to the dome lamp  3  in a series connection manner. Furthermore, sub-circuits  14  to  16  of the map lamp  2  are extended up to the rear reading lamp  4 , so that the cooperation of a courtesy circuit  15  in the map lamp  2  and the rear reading lamp  4  can be simultaneously canceled. 
   Circuit arrangements of both the map lamp  2  and the rear reading lamp  4  are the same as those in the first embodiment. The sub-circuits  14  to  16  continued from the map lamp  2  are terminated in the rear reading lamp  4 , so that the map lamp  2  is not directly connected to the dome lamp  3 . The main circuits  11  to  13  are directly connected to the dome lamp  3 . 
   Therefore, in accordance with the operation of the cancel switch  6 , the cooperation of the courtesy circuit  15  in the map lamp  2  and the rear reading lamp  4  can be canceled while the cooperation of the dome lamp  3  is maintained irrespective of the operation of the cancel switch  6 . 
   Although the present invention has been shown and described with reference to specific preferred embodiments, various changes and modifications will be apparent to those skilled in the art from the teachings herein. Such changes and modifications as are obvious are deemed to come within the spirit, scope and contemplation of the invention as defined in the appended claims. 
   For example, the light emitters  20 ,  24 ,  28  may be filament type bulbs, LEDs of electronic elements, or the like. Bus bars and wire harnesses may be selectively used in any of the circuits in accordance with the required circuit configuration. The respective switch is not limited to the above-described slide switch. 
   The respective lamp modules are not limited to the modules designed for ceiling lamps of the vehicle, but may be realized by employing lamps mounted around an instrument panel of the vehicle, and other sorts of lamps. Instead of the courtesy circuit  12 , there may be adopted other notification signal circuits for indicating the condition of the window or the tire pressure, for example. 
   Regarding the first and the second embodiments, the rear reading lamp may be omitted.