JP2007083841A - Rear view imaging system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rear view imaging system for a vehicle which can be mounted easily and obtains a fine image. <P>SOLUTION: The rear view imaging system 100 for a vehicle comprises a camera 1 which is housed together with a light-emitting diode 21 in a backlight housing space 95 at the rear of a vehicle 99, an image signal transmitting means 17 which puts an output signal S1 from the camera 1 by frequency modulation and superposes the modulated signal S1 on a current passing through a backlight power supply line 3 to transmit the modulated signal S1, a power supply means which supplies power from a battery BAT to the light-emitting diode 21 and to the camera 1 via the backlight power supply line 3, and an image signal separating means 19 which receives the frequency-modulated output image signal S2 which is superposed on the current passing through the backlight power supply line 3 and supplied to the separating means 19, and demodulates the output image signal S2 to extract an image signal S3 therefrom. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of a vehicle rear imaging system including a vehicle rear imaging camera and a monitor device for confirming at a driver's seat a rear view when a vehicle (typically an automobile) is moving backward.

  In a general conventional vehicle rear-view system, when a rear-view camera (generally a video camera) is mounted near the bumper or window frame at the rear of the vehicle and the shift gear is put in the back Wiring so that the system can be turned on only when the power is turned on (to save power), and the rear image captured by the camera is displayed on a liquid crystal or CRT monitor installed in the vicinity of the driver's seat. It is configured so that it is possible to easily check the rear of the vehicle.

  In general, the power of the camera is supplied from a power supply line of an existing backlight (reverse light) that illuminates the rear and informs the outside when the vehicle backs, and outputs from the camera. NTSC signals are used as video signals, and many of them require wiring to the monitor device with a dedicated signal cable.

  For this reason, when installing a rear-viewing system retrofitted to a vehicle, it would take a lot of trouble to install a new video signal transmission wiring from the camera to the monitor device. The issue was whether to construct.

  In this regard, in [Patent Document 1] below, paying attention to the power supply line of the backlight (generally a white light bulb), the output video signal from the camera is superimposed on the backlight power supply line and transmitted to the monitor device. Thus, a device is described in which a dedicated signal cable between the camera and the monitor device is not required.

  That is, in the idea of [Patent Document 1], the vehicle rearward confirmation device has a circuit configuration as shown in FIG. 4, and the output video signal from the camera 1 that images the rear of the vehicle attached to the rear of the vehicle is used as the RF modulator. 4, and is superimposed on the backlight power supply line 3 via the capacitor C <b> 2 and sent to the monitor device 5 side. On the monitor device 5 side, the output video signal superimposed on the backlight power supply line 3 is transmitted. Is demodulated by the video signal detection circuit 6 via the capacitor C1 and displayed on the monitor device 5. Here, the capacitors C1 and C2 in FIG. 4 are DC cut filters, and the inductors L1 and L2 are filters for preventing AC components from entering the power supply side.

  4 is supplied to the backlight 2 through the backlight power supply line 3 via the back gear switch 12, and the back gear switch 12 is connected to the shift lever of the vehicle. It is linked with the back gear and automatically turns on when the back gear is engaged.

  The backlight 2 is provided with a relay 11 and a comparator 10, and the comparator 10 is configured to supply an output to the transistor Q1 and turn on the relay 11 only when power of + 10V or more is supplied. Yes.

  Further, the power of the camera 1 is also supplied from the backlight power supply line 3. In parallel with the comparator 10, there is provided a comparator 7 which is turned on by the input of a power supply of + 8V or higher. The output of the comparator 7 turns on the transistor Q2 to operate the stabilized power supply 8 to operate the + 5V power supply. Is supplied to the camera 1 and the RF modulator 4.

  With the above circuit configuration, when the back gear is engaged, the back gear switch 12 is turned on, the backlight 2 is turned on, and power is supplied to the camera 1 and the RF modulator 4, and an image behind the vehicle is sent to the monitor device 5. It is done.

  When the monitor switch 9 in FIG. 4 is manually turned on, the camera power of +9 V is supplied from the monitor device 5 through the diode D2 to the backlight power supply line 3, and the comparator 7 is turned on to turn on the camera 1. In addition, power is supplied from the stabilized power supply 8 only to the RF modulator 4 so that it is possible to manually confirm the rearward even when the vehicle is not backed.

Japanese Utility Model Publication No. 5-74989

  As mentioned above, when installing a rear-view system on a vehicle as a retrofit, how to attach the camera to the vehicle and install the wiring from the camera to the monitor device to transmit the output video signal is a problem However, the output video signal from the camera 1 is superimposed on the backlight power supply line 3 as in the circuit configuration of FIG. 4 of the invention of the [Patent Document 1] (the RF modulator described in [Patent Document 1] is an AM). It is considered a modulator.) Sharing wiring is a simple, efficient and remarkable means, but generally the power line potential supplied from the vehicle battery is unstable and cannot be ignored. Therefore, if the output video signal is superimposed by an amplitude (AM) modulation method using a compressed carrier wave used in television broadcasting, the influence of noise close to a direct current component can be avoided. Can be synchronized is out fear spared, but the noise components of higher frequencies affect the output video signal, it is difficult to suppress the occurrence of so-called snow noise.

  As a result, the video signal demodulated from the backlight power supply line 3 is affected by power noise (especially pulse noise), and the image is disturbed.

  In addition, although there is no particular description of the installation location of the camera 1 in [Patent Document 1], in the retrofit of the rear imaging system, the camera is attached to an appropriate position without impairing the appearance of the rear part of the vehicle, and the back side. There is a problem that it is very difficult to supply power from the power supply line of the light.

  The present invention has been made in view of the above circumstances, and even with a rear-facing vehicle rear-photographing system, a camera for rear-photographing a vehicle can be attached to an optimal position in the rear portion of the vehicle without damaging the appearance. An object of the present invention is to provide a vehicle rear-photographing system configured such that transmission of an output video signal from a camera to a monitor device can be stably performed using an existing power line and a good image can be displayed on the monitor device. And

  The present invention is directed to a vehicle rear-viewing system in which a camera 1 for rear-side shooting stored together with a light-emitting diode 21 for a backlight source in a backlight storage space 95 at the rear of the vehicle and an output video signal of the camera 1 are provided. The video signal transmission means 17 that FM modulates S1 and superimposes it on the backlight power supply line 3 of the vehicle and transmits it through the backlight power supply line 3 of the vehicle 99. And the power supply means for supplying power to the light emitting diode 21 and the camera 1, and the FM-modulated output video signal S2 of the camera 1 supplied in a superimposed manner on the backlight power supply line 3 to demodulate the video signal S3. The above-mentioned problem is solved by providing a vehicular rear-viewing system 100 comprising a video signal sorting unit 19 for taking out the video signal.

The vehicle rear imaging system according to the present invention is configured as described above,
(1) Since the backlight power supply line already wired to the vehicle is used as the transmission path of the output video signal connecting the camera and the monitor, the installation cost can be greatly reduced and the FM is strong against pulse noise. Since this is a method of superimposing the modulated output video signal, image disturbance due to power supply noise can be greatly reduced.
(2) A space-saving and energy-saving light emitting diode (LED) is installed as an alternative backlight in the existing backlight (reverse light) storage space at the rear of the vehicle, and a small camera is used together. Since it is housed, the rear photographing system can be easily attached without processing a new vehicle and without damaging the appearance.

  DESCRIPTION OF EMBODIMENTS Embodiments of a vehicle rear imaging system according to the present invention will be described with reference to the drawings. Note that members similar to those in FIG. 4 according to [Patent Document 1] of the known technology are denoted by the same reference numerals.

  FIG. 1 is a block circuit diagram of a vehicle rearward imaging system according to the present invention. FIG. 2 is a perspective view for explaining a camera, a light emitting diode, and a video signal transmission means of the vehicle rear photographing system according to the present invention disposed in the backlight storage space of the vehicle. FIG. 3 is a perspective view for explaining an example of arrangement and wiring in the vehicle of the vehicle rear imaging system according to the present invention.

  1 to 3 is a vehicle rear-viewing camera 100 housed in a backlight storage space 95 at the rear of a vehicle 99 together with a light-emitting diode 21 for a backlight light source, The video signal transmission means 17 for FM-modulating the output video signal S1 of the camera 1 and superimposing it on the backlight power supply line 3 of the vehicle, and the battery BAT. A power supply means for supplying power to the light emitting diode 21 and the camera 1 from above, and an output video signal (FM modulated signal) S2 of the FM-modulated camera 1 supplied by being superimposed on the backlight power supply line 3 And a video signal classification unit 19 that demodulates and extracts the video signal S3. It should be noted that the vehicle rear imaging system 100 is installed near the driver's seat and has a battery BAT. And a monitor device 5 that displays an image of the video signal S3 obtained by the video signal sorting means 19 while being supplied with power.

  As shown in FIG. 1, the video signal transmission means 17 FM-modulates the output video signal S1 to a predetermined high-frequency carrier by the FM modulator 24, and the FM-modulated high-frequency (FM-modulated signal S2). In order to superimpose on the backlight power supply line 3, inductors L1 and L2 are connected to both ends, and the high frequency impedance is increased while the DC impedance is kept low to superimpose the FM modulation signal S2. In addition, in order to transmit a high frequency, the impedance of a transmission line is matched. Capacitors C1 and C2 are for DC cut.

  In the present invention, since the output video signal S1 is FM-modulated and transmitted by applying analog transmission instead of costly digital transmission, it is possible to strongly eliminate the influence of spike noise. Is possible. Incidentally, generally, when the output video signal S1 is FM-modulated, a wide frequency band is required, which is inconvenient for wireless transmission, but in the case of wired transmission, the frequency modulation degree can be taken deeply, so noise elimination capability Can be deepened to a practically sufficient value.

  Next, as shown in FIG. 1, the video signal classification means 19 demodulates the FM modulation signal S2 transmitted by being superimposed on the backlight power supply line 3 by an FM demodulator (detection circuit) 26. The video signal S3 is taken out and sent to the monitor device 5.

  The power supply means to the light emitting diode 21, the camera 1, and the video signal transmission means 17 is connected to the battery BAT.1 by turning on the back gear switch 12 when the shift knob 97 is put in the back gear. Power is supplied from. The monitor device 5 and the video signal sorting means 19 are the same, but the monitor device 5 may be used also as a display device for other devices (navigation system, television, etc.). It is good also as supply.

  Next, in the present invention, the installation location and installation means of the camera 1 are shown in FIG. 3 and FIG. 2 (a) in order to achieve both a location where a good rear view is obtained and an installation location that does not impair the appearance. In place of the existing backlight 2 (incandescent light bulb) that is the light source of the backlight stored in the existing backlight storage space 95 at the rear of the vehicle, a printed circuit board as shown in FIG. A small camera 1 (about the size of the tip of a little finger) is installed in the center of 22, and several high-intensity light-emitting diodes 21 (light emission color close to white) are arranged around the camera 1. The printed circuit board 22 is provided with video signal transmission means 17 in which an IC, a capacitor, an inductor, a terminal and the like in which the FM modulation circuit 24 is integrated are mounted and wired. The transparent cover 15 of the backlight is provided with multi-surface treatment of reflection and refraction in the light-transmitting portion of the light-emitting diode 21 in the same manner as in the past, so that the light-transmitting portion 16 of the lens of the central camera 1 is flat. Alternatively, it is important to secure a field of view so that the rear side of the vehicle is clearly imaged in a concave lens shape.

  According to the above configuration, by changing the light source of the backlight from the conventional back lamp (bulb) 2 to the light emitting diode 21, the power consumption can be reduced compared to the light bulb and the heat generation is much less, so Therefore, it is possible to minimize the thermal influence on the camera 1 arranged in the same manner, and it is possible to make the illumination and the camera coexist in the same storage space 95 in a compact manner, and the output from the camera 1 The video signal transmission means 17 for superimposing the video signal S1 on the backlight power supply line 3 can also be easily mounted on the printed circuit board 22.

  According to the configuration of the rear photographing system 100 for a vehicle according to the present invention described in detail above, the battery BAT.B via the existing voltage divider 98 installed in the vehicle 99 as shown in FIG. The back gear switch 12 that is turned ON / OFF by the shift gear 97, the newly installed monitor device 5 of the system, the camera 1, the light emitting diode 21 and others maximize the backlight power supply line 3 and other existing wiring. Because it is constructed with limited use, it was a matter of concern for the conventional back monitor system, (1) Difficult point of work to add wiring from the room to the outside of the vehicle, (2) Location of the place where the camera 1 is mounted It is possible to solve the problems such as difficulty in securing and mounting, (3) the appearance and the appearance is not impaired, and (4) the backlight power supply line 3 for transmitting the output video signal. The problem of image disturbance due to power supply noise when used can be solved.

1 is a block circuit diagram of a vehicle rear imaging system according to the present invention. 1 is a perspective view for explaining a camera, a light emitting diode, and a video signal transmission unit of a vehicle rear-viewing system according to the present invention that are arranged in a backlight storage space of a vehicle. It is a perspective view for demonstrating the example in the vehicle and arrangement | positioning and wiring of the vehicle back imaging | photography system which concerns on this invention. It is a circuit diagram of the vehicle back confirmation apparatus of the well-known technique described in [patent document 1].

Explanation of symbols

1 Camera
2 Back light (bulb)
3 Backlight power supply line
4 RF modulator
5 Monitor device
6 Video signal detection circuit
12 Back gear switch
15 Backlight transparent cover
17 Video signal transmission means
19 Video signal sorting means
21 Light emitting diode
22 Printed circuit board
24 FM modulator
25 FM demodulator
95 Backlight storage space
97 shift gear
98 Distributor
99 Vehicle 100 Vehicle rear imaging system BAT. Battery C1, C2 Capacitor (DC cut filter)
L1, L2 Inductor (AC filter)
S1 Output video signal
S2 FM modulated output video signal (FM modulated signal)
S3 Demodulated video signal

Claims (1)

In the vehicle rear-view system,
A camera for taking a picture of the rear of the vehicle stored in a backlight storage space at the rear of the vehicle together with a light emitting diode for a backlight light source;
Video signal transmission means for FM-modulating an output video signal of the camera and superimposing it on a backlight power supply line of a vehicle;
Power supply means for supplying power from the battery to the light emitting diode and the camera via the backlight power supply line of the vehicle;
Video signal classification means for demodulating the FM-modulated output video signal supplied from the backlight power supply line and taking out the video signal;
A vehicle rear imaging system comprising:

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