Abstract:
A model apparatus is provided in that images from a model vehicle can be continuously watched on a monitor even when the model vehicle travels through a place surrounded by a shielding material. An image signal transmission route from the model vehicle to the monitor uses conductive rail lines for guiding the model vehicle and supplying drive power to a drive motor, so that even when there is an electromagnetic shielding material in the vicinity of a place where the model vehicle travels, the images can be continuously displayed on the monitor.

Description:
INCORPORATION BY REFERENCE  
       [0001]     The present application claims priority under 35 U.S.C. § 119 to Japanese patent application No. 2003-281082 filed on Jul. 28, 2003. The content of the application is incorporated herein by reference in its entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a model apparatus in that a model train is driven along a track, and more specifically it relates to a model apparatus in that images viewed from the inside of the model train are displayed on a monitor separated from the model train.  
         [0004]     2. Description of the Related Art  
         [0005]     A model apparatus has been known, in which a model train traveling on a railroad has an imaging camera at the head thereof for picturing images of the traveling direction so that one can see images of the traveling direction as if he or she were sitting on a driver&#39;s seat by displaying the images on a monitor installed at a position separated from the model train, in Japanese Unexamined Patent Application Publication No. 11-319332, for example.  
         [0006]     This conventional model apparatus  100  will be described with reference to  FIG. 4 . To a railroad  102 , on which a model train  101  travels, an AC power supply  103  for driving the model train  101  and a train controller  104  having a control unit  104 a housed therein are connected.  
         [0007]     The control unit  104   a  includes an operation signal processor  105  for receiving operation signals representing various operations of the train controller  104  so as to display the operational contents by flashing lamps of the train controller  104  and a digital control-signal converter  106  for converting an operational signal into a digital control-signal so as to be fed to the railroad  102 .  
         [0008]     The model train  101  includes a decoder  108  for receiving a digital control signal via wheels  107  rolling on the railroad  102 , a drive motor  109  controlled by the decoder  108 , a CCD camera  110  for imaging the traveling direction of a train, a transmitter  111  connected to the output of the CCD camera  110  and having a sending antenna  111   a , and a power supply filter  115  for supplying DC voltages to the decoder  108 , the CCD camera  110 , and the transmitter  111  by converting AC voltages supplied to the railroad  102  via the wheels  107  into the DC voltages, these elements being mounted on the model train  101 .  
         [0009]     At a position separated from the model train  101 , for example, in the vicinity of the train controller  104 , a tuner  112  having a receiving antenna  112 a and a monitor  113  connected to the output of the tuner  112  are arranged.  
         [0010]     On the model train  101  having the drive motor  109  mounted thereon, a weight  114  made of a metal block shown in  FIG. 4  is generally mounted so as to increase the self-weight of the model train  101 . Thereby, the AC power supply voltage is transmitted to the decoder  108  and the power supply filter  115  without attenuating the AC power supply voltage by contact resistance due to the reduction in the contact resistance between the wheel  107  and the railroad  102 , and also the model train  101  can efficiently travel without slippage between the railroad  102  and the wheel  107  drivingly connected to the drive motor  109 .  
         [0011]     In a model apparatus  100  structured in such a manner, when the train controller  104  is operated so as to produce control signals of acceleration and deceleration of the model train  101 , digital control signals converted by the digital control-signal converter  106  are entered to the decoder  108  via the railroad  102  and the wheels  107 . The decoder  108  controls the rotation of the drive motor  109  based on the digital control signals so that the model train  101  is accelerated or decelerated in accordance with the control signal.  
         [0012]     The CCD camera  110  mounted at the front of the model train  101  produces a photo-electrically converted image signal of a progress direction to the transmitter  111 , which in turn sends the high-frequency signal modulated from the image signal from the sending antenna  111   a.    
         [0013]     The high-frequency signal sent from the sending antenna  111   a  is received to the receiving antenna  112   a  by the tuner  112  tuning on a channel of the sending frequency band of the transmitter  111  so as to produce the demodulated image signal on the monitor  113 .  
         [0014]     Thereby, one can operate the train controller  104  viewing images of the progress direction as if he or she were sitting on the driver&#39;s seat of the model train  101 .  
         [0015]     In the conventional model apparatus  100  described above, an image signal picked up by the CCD camera  110  is transmitted as a radio signal from the sending antenna  111   a  adjacent to the model train  101  to the receiving antenna  112   a  adjacent to the monitor  113 , wherein when the model train  101  passes thorough a tunnel and a bridge made of conductive materials, these materials block off the high-frequency radio signal, so that the image signal is temporarily cut off and the image on the monitor  113  is hard to watch. Since only a radio signal with weak power can be used especially in a general model apparatus, this problem becomes noticeable furthermore in surroundings that electromagnetic waves exist in the vicinity.  
         [0016]     Also, in order to transmit an image signal to the monitor  113  by a wireless system, expensive circuit elements such as the transmitter  111 , the sending and receiving antennas  111   a  and  112   a , and the tuner  112  are required so as to increase the entire cost of the model apparatus  100 .  
         [0017]     Moreover, attaching the sending antenna  111   a  to the model train  101  impairs the appearance of a model of an actual object.  
         [0018]     Also, mounting the weight  114  on the model train  101  for increasing its self weight requires additional components and an assembling process for fixing them to the model train  101 .  
       SUMMARY OF THE INVENTION  
       [0019]     The present invention has been made in view of such problems, and it is an object of the present invention to provide a model apparatus in that images from a model train can be continuously watched on a monitor even when the model train travels through a place surrounded by a shielding material.  
         [0020]     In order to solve the problem described above, according to the present invention, an FM modulated image signal from an imaging camera is entered to a track composed of a conductive rail line via a contact portion, and an FM demodulation circuit connected to the track demodulates the modulated image signal so as to be fed to a monitor. Since the image signal is entered to the FM demodulation circuit connected to the track as the FM-modulated image signal, the image signal is transmitted from a model train to the monitor without being affected by noise due to a drive power supply and a drive motor connected to the track.  
         [0021]     According to the present invention, the image signal transmission route from the model train to the monitor uses the track composed of the conductive rail line for guiding the model train and supplying drive power to the drive motor, so that components required for a radio transmission system are eliminated so as to reduce the cost of the model apparatus.  
         [0022]     Also, even when there is an electromagnetic shielding material in the vicinity of a place where the model train travels, the image can be continuously displayed on the monitor.  
         [0023]     Since the model train is not required to have a sending antenna mounted thereon, the model train may have a shape similar to a real train.  
         [0024]     According to an embodiment of the present invention, the FM modulated image signal may be output to a rail track via wheels rolling in contact with the track. Because of rolling contact between the wheels and the rail track, although the contact pressure is not stable, the FM modulated image signal is transmitted to the track, so that the image signal can be demodulated without being affected by changes in the contact pressure. Since the wheels of the model train are used, the modulated image signal can be output to the track without impairing appearance of the model.  
         [0025]     Also, since the model train travels on the track with a plurality of wheels, the modulated image signal can be output to the track via the plurality of wheels in parallel, so that even when contact failure is produced between a specific wheel and the track, the modulated image signal can be securely output to the track.  
         [0026]     According to another emdobiment of the present invention, the model train having the drive motor mounted thereon may include an auxiliary battery mounted thereon, so that the train weight is increased without mounting a weight thereon and slippage between the wheels and the track is reclosed.  
         [0027]     Since the train weight is increased without mounting the weight thereon for preventing derailing of the model train and reducing the slippage between the wheels and the track, the weight is not necessary to be prepared and assembled on the train.  
         [0028]     According to a further embodiment of the present invention, the contact pressure between the wheels of the model train having the drive motor and the auxiliary battery mounted thereon and the track may be large, so that the attenuation of the modulated image signal due to the contact resistance is small when the signal is output to the track.  
         [0029]     Further, the modulated image signal can be output to the track by reducing the influence due to the contact resistance between the wheels of the model train and the track. Also, since the wheels of the model train having the drive motor have greater transition so signal noise, which may interference with the modulated image signal, caused by the slipping of the wheels where the track may not be produced.  
         [0030]     According to another embodiment of the present invention, the modulated image signal may be output in a balanced form to a pair of rail tracks via the wheels of the model train. Since the modulated image signal is output in a balanced form to the pair of rail tracks, even when wheels are placed on the pair of rail tracks without considering the direction of the model train relative thereto, the FM modulation circuit, the pair of rail tracks, and the FM demodulation circuit are matched together, so that the modulated image signal can be securely demodulated. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0031]      FIG. 1  is a block diagram of an entire model apparatus according to an embodiment of the present invention;  
         [0032]      FIG. 2  is a schematic block diagram of a model train of the present invention;  
         [0033]      FIG. 3  is a schematic block diagram of an FM modulation circuit unit of the present invention; and  
         [0034]      FIG. 4  is a schematic block diagram of a conventional model apparatus. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]     A model apparatus according to an embodiment of the present invention will be described below with reference to FIGS.  1  to  3 . As shown in  FIG. 1 , the model apparatus according to the embodiment is a model apparatus  1  in that a model train  2  scaled down from a real railroad train is driven to travel on rail tracks  3  and  3 , which are tracks downsized in the same scale, and a DC power supply  4  is connected to the rail tracks  3  and  3  via a controller  5  as a drive power supply for the model train  2 .  
         [0036]     The DC power supply  4  is a power supply with a 5 V DC, for example, and applies a DC voltage, in which polarity and voltage are controlled by the controller  5 , between a pair of the parallel rail tracks  3  and  3 . The DC power supply  4  also supplies operating power to an FM demodulation circuit unit  6 , which will be described later and is accommodated within a common control box  10  together with the DC power supply  4  and the controller  5 .  
         [0037]     The pair of rail tracks  3  and  3  are depicted as a continuous loop, for example an ellipse, in the drawing; alternatively, one end thereof may be terminated.  
         [0038]     As shown in  FIG. 2 , the model train  2  is composed of three trains including a front train (i.e., an engine)  2 A, an intermediate train  2 B, and a rear end train (i.e.caboose)  2 C, which are connected to each other. On the rear end train  2 C, a drive motor  7  is mounted for driving the entire model train  2 . To the drive motor  7 , a DC voltage, which is supplied between the rail tracks  3  and  3 , is applied via wheels  8 C and  8 C of the rear end train  2 C. The drive motor  7  rotates in a forward or reverse direction in accordance with the polarity of the DC voltage applied between the rail tracks  3  and  3 , and rotates at a rotation speed approximately proportional to the voltage. The rotation of the drive motor  7  is transmitted to the wheels  8 C and  8 C, which are drive wheels, through a worm gear (not shown) . Therefore, the travel direction and speed of the model train  2  are controlled by operating the above-mentioned controller  5  so as to control the voltage and polarity to be supplied between the rail tracks  3  and  3 .  
         [0039]     A low-pass filter  9  is connected to a power line connecting to the drive motor  7  in series so as to prevent high-frequency component noise produced by the drive of the drive motor  7  from flowing between the rail tracks  3  and  3 .  
         [0040]     On the front train  2 A, a C-MOS camera  11  is mounted so as to pick up images of the progress direction of the model train  2 . The output of the C-MOS camera  11  is connected to an FM modulation circuit unit  12  mounted on the intermediate train  2 B so as to output a photo-electrically converted image signal.  
         [0041]      FIG. 3  is a block diagram of the FM modulation circuit unit  12 . The image signal produced by the C-MOS camera  11  is amplified by a low-frequency amplifier circuit  13  composed of an operationalamplifier so as to enter a clamp circuit  14 . The clamp circuit  14  clamps a synchronization signal contained in the image signal so as to be output to an FM modulation circuit  16  via a buffer  15 . The buffer  15  coverts impedance so as to match with the input impedance of the FM modulation circuit  16 .  
         [0042]     To the FM modulation circuit  16 , an oscillation circuit  17  is connected for producing a constant high-frequency signal as a carrier wave. The FM modulation circuit  16  FM-modulates the carrier wave as a signal wave by the image signal received from the buffer  15  so as to produce the modulated signal to a balun transformer  18 .  
         [0043]     The balun transformer  18  is a matching converter for connecting the output of the FM modulation circuit  16 , which is an unbalanced line, to a balanced line, and outputs the modulated image signal to a pair of signal-output lines  19  and  19 , which are balanced lines.  
         [0044]     The pair of signal-output lines  19  and  19  are to be connected to the both sides of the wheels  8  and  8  rolling in contact on the rail tracks  3  and  3 , respectively. In  FIG. 2 , not only to wheels  8 B and  8 B of the intermediate train  2 B having the FM modulation circuit unit  12  mounted thereon, but also to wheels  8 C and  8 C of the rear end train  2 C having the drive motor  7  mounted thereon, the branched signal-output lines  19  and  19  are electrically connected. Therefore, the modulated image signals are output to the pair of rail tracks  3  and  3  from a plurality of the lateral wheels  8  and  8 , respectively.  
         [0045]     The circuits of the C-MOS camera  11  and the FM modulation circuit unit  12  are operated by two auxiliary batteries  20  and  20  mounted on the rear end train  2 C as power supplies. As shown in  FIG. 2 , the output from the two auxiliary batteries  20  connected in series is entered to a booster circuit  21  mounted on the intermediate train  2 B. The booster circuit  21  is for boosting the 3V DC voltage of the auxiliary battery  20  to 5V, and the 5V DC voltage is output to the C-MOS camera  11  and the FM modulation circuit unit  12  via the low-pass filter  22  in order to be used as operating voltages thereof. The low-pass filter  22  cut the noise produced by the booster circuit  21 .  
         [0046]     As shown in  FIG. 1 , the modulated image signal produced in the pair of rail tracks  3  and  3  is entered to the FM demodulation circuit unit  6  connected to the rail tracks  3  and  3 . The FM demodulation circuit unit  6  demodulates the modulated image signal to an image signal by FM detection. The modulated image signal is superimposed on the DC voltage of the DC power supply  4  to be applied to the pair of rail tracks  3  and  3 . Although the modulated image signal entering the FM demodulation circuit unit  6  contains noise due to changes in voltage levels by the rolling contact between the wheels  8  and the rail tracks  3  and due to the rotational operation of the drive motor  7 , because of the modulated image signal due to FM modulation, the effect of the noise is eliminated during demodulation, enabling the image signal to be demodulated continuously and securely.  
         [0047]     The image signal produced from the FM demodulation circuit unit  6  is output in the monitor  23  connected to the output of the FM demodulation circuit unit  6 . Thereby, images of the progress direction of the model train  2  can be watched at a position separated from the model train  2 . In the drawing, the monitor  23  is located in the vicinity of the controller  5  for controlling the travel of the model train  2 , for example, so that the controller  5  can be operated as if the progress direction were viewed from a train driver&#39;s seat.  
         [0048]     According to the embodiment, since on the rear end train  2 C having the drive motor  7  mounted thereon, the two auxiliary batteries  20  and  20  for supplying electric power to the C-MOS camera  11  and the FM modulation circuit unit  12  are mounted, it is not necessary to have a weight for increasing the weight of the train in contrast to a conventional one. The contact resistance between the wheels  8 C and the rail tracks  3  is thereby reduced, so that the modulated image signal can be entered to the rail tracks  3  without attenuating the signal. Moreover, since the drive wheels  8 C cannot slip on the rail tracks  3 , the model train  2  can be efficiently driven to travel, and furthermore noise produced by slipping in contact between the drive wheels  8 C and the rail tracks  3  is prevented from being superimposed on the modulated image signal.  
         [0049]     In the model apparatus  1  described above, a DC voltage is applied to the rail tracks from the DC power supply for driving the model train to travel; alternatively, an AC voltage may be applied thereto from an AC power supply as long as the modulated FM signal can be demodulated.  
         [0050]     The FM modulation circuit and the drive motor may be mounted on any train, so that they may be mounted on the front train having the imaging camera mounted thereon. Therefore, it is not necessarily to have a plurality of trains connected to each other, and only one train may be used.  
         [0051]     Furthermore, the direction picked up by the imaging camera is not limited to the progress direction of the model train, and any direction may be picked up. Therefore, the camera is not necessarily to be mounted on the head of the model trains, and may be arranged at any arbitrary position and in any arbitrary direction.  
         [0052]     According to the embodiment described above, the model apparatus is exemplified; alternatively, a model apparatus may be applied in that a train such as a racing car is driven to travel on a model roadway with a conductive track.  
         [0053]     Moreover, the controller for controlling the travel of the model train is not necessarily required, so that a model apparatus in that a model train travels at a constant speed may be applied to the present invention.