In-vehicle devices, programs, and rearview camera systems

Abstract

This system allows switching between the trailer-side rearview camera image and the tractor-side rearview camera image without requiring the replacement of connectors or the addition of monitors. [Solution] A trailer-side rearview camera 20 installed on trailer T1 is connected via a detachable connector 21C, and a tractor-side rearview camera 30 installed on tractor T0 is also connected. The in-vehicle unit 10 displays images based on the video signals from the trailer-side rearview camera 20 or the tractor-side rearview camera 30. The unit comprises a monitor 11 for displaying images, and a CPU that, when receiving a video signal from the trailer-side rearview camera 20, displays images on the monitor 11 based on the video signal received from the trailer-side rearview camera 20, and when not receiving a video signal from the trailer-side rearview camera 20 but receiving a video signal from the tractor-side rearview camera 30, displays images on the monitor 11 based on the video signal received from the tractor-side rearview camera 30.

Description

Technical Field

[0001] The present invention relates to an on-vehicle device, a program, and a back-up camera system.

Background Art

[0002] As a back-up camera system for trucks, there is known a system in which back-up cameras are installed on the left and right sides of a trailer, and images captured by the left and right back-up cameras are displayed on a monitor installed in the vehicle compartment (see, for example, Patent Document 1). In the back-up camera system described in Patent Document 1, the left and right back-up cameras are movable between an imaging position and a storage position by a storage moving mechanism.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] A tractor (tractor head) may be parked or moved with the trailer detached. Therefore, from the viewpoint of improving parking convenience and traffic safety, it is desirable to install a back-up camera on the tractor. However, installing the back-up camera on the trailer is more suitable for practical use as a device for checking the area immediately behind the vehicle when reversing than installing the back-up camera on the tractor. Therefore, the actual situation is that back-up cameras are installed not only on the tractor but also on the trailer.

[0005] When installing backup cameras on both the tractor and trailer, it is necessary to display the trailer's backup camera image on the in-cabin monitor when the tractor and trailer are coupled, and the tractor's backup camera image on the in-cabin monitor when the tractor and trailer are uncoupled. This requires either switching the connectors to the connection equipment located deep inside the cabin, or installing two monitors, one for the tractor and one for the trailer. In such cases, the workload for the driver and electrical contractors may increase, costs may increase, and the driver's view may be obstructed.

[0006] In view of the above circumstances, the present invention aims to enable switching between the video feed from the trailer-side rearview camera and the video feed from the tractor-side rearview camera without requiring the replacement of connectors or the addition of monitors. [Means for solving the problem]

[0007] The in-vehicle device according to the present invention is connected to a trailer-side rearview camera installed on a trailer via a detachable connection terminal, and to a tractor-side rearview camera installed on a tractor, and displays an image based on the video signal from the trailer-side rearview camera or the tractor-side rearview camera, and comprises a display unit for displaying an image, and a control unit which, when a video signal is received from the trailer-side rearview camera, causes the display unit to display an image based on the video signal received from the trailer-side rearview camera, and when a video signal is not received from the trailer-side rearview camera but a video signal is received from the tractor-side rearview camera, causes the display unit to display an image based on the video signal received from the tractor-side rearview camera.

[0008] The present invention relates to a program for operating an in-vehicle device that displays an image based on a video signal from the trailer-side rearview camera or the tractor-side rearview camera, to which a trailer-side rearview camera installed on a trailer is connected via a detachable connector terminal, and a tractor-side rearview camera installed on a tractor is also connected. The program is for performing the following processes: when a video signal is received from the trailer-side rearview camera, the program displays an image on the display unit of the in-vehicle device based on the video signal received from the trailer-side rearview camera; and when a video signal is not received from the trailer-side rearview camera but a video signal is received from the tractor-side rearview camera, the program displays an image on the display unit based on the video signal received from the tractor-side rearview camera.

[0009] The rearview camera system according to the present invention comprises a trailer-side rearview camera installed on a trailer, a tractor-side rearview camera installed on a tractor, and an on-board unit to which the trailer-side rearview camera is connected via a detachable connector terminal, to which the tractor-side rearview camera is connected, and which displays an image based on the video signal from the trailer-side rearview camera or the tractor-side rearview camera, wherein the on-board unit comprises a display unit for displaying an image, and a control unit that, when receiving a video signal from the trailer-side rearview camera, causes the display unit to display an image based on the video signal received from the trailer-side rearview camera, and when not receiving a video signal from the trailer-side rearview camera, causes the display unit to display an image based on the video signal received from the tractor-side rearview camera. [Effects of the Invention]

[0010] According to the present invention, it is possible to switch between the image from the trailer-side rearview camera and the image from the tractor-side rearview camera without requiring the replacement of connectors or the addition of monitors. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic diagram of a backup camera system according to one embodiment of the present invention. [Figure 2] Figure 2 is a schematic diagram of a backup camera system according to one embodiment of the present invention. [Figure 3] Figure 3 is a block diagram illustrating the schematic configuration of the in-vehicle device shown in Figures 1 and 2. [Figure 4] Figure 4 is a front view showing the in-vehicle unit shown in Figure 1, etc. [Figure 5] Figure 5 is a front view showing the in-vehicle unit shown in Figure 1, etc. [Figure 6] Figure 6 is a schematic diagram of a backup camera system according to another embodiment of the present invention. [Figure 7] Figure 7 is a schematic diagram of a rear camera system according to another embodiment of the present invention. [Figure 8] Figure 8 is a block diagram showing the schematic configuration of the in-vehicle unit and camera selector shown in Figures 6 and 7. [Modes for carrying out the invention]

[0012] The present invention will be described below in accordance with preferred embodiments. However, the present invention is not limited to the embodiments shown below, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, in the embodiments shown below, some parts of the configuration are omitted in terms of illustration and description. For details of the omitted technologies, publicly known or well-known technologies can be applied as appropriate, to the extent that they do not contradict the content described below.

[0013] Figures 1 and 2 show a schematic diagram of a backup camera system 1 according to one embodiment of the present invention. The backup camera system 1 shown in these figures is used in practice as a vehicle rear-view device for trucks.

[0014] A backup camera system 1 includes an on-vehicle device 10, a trailer-side backup camera 20, a tractor-side backup camera 30, and a power box 40. The on-vehicle device 10 includes a monitor 11, operation buttons 12, and the like, is arranged at the upper center of the front window, and functions as an inner mirror-type backup monitor and a digital inner mirror. Note that the on-vehicle device 10 may be of a stationary type installed on a dashboard or a built-in type.

[0015] The on-vehicle device 10 is connected to a constant power supply, an ACC (accessory) power supply, a ground (GND), and the like, and operates by being supplied with electric power from the constant power supply or the ACC power supply. Further, the on-vehicle device 10 has a function as a drive recorder, and receives input of operation signals of a turn signal, a brake, and a shift lever, traveling information such as vehicle speed, position information obtained by GPS (Global Positioning System), and the like. Note that it is not essential for the on-vehicle device 10 to have a function as a drive recorder, and the on-vehicle device 10 only needs to have at least a function as a backup monitor.

[0016] The monitor 11 displays a screen for performing initial settings in addition to images captured by cameras such as the trailer-side backup camera 20. The screen includes an item for setting the type (standard) of a video signal of a camera such as the trailer-side backup camera 20.

[0017] A power cable 14 is connected to an external terminal of the on-vehicle device 10. The power cable 14 is connected to a relay cable 21 via a connector 14C. The power cable 14 is a composite cable in which a signal line and a power line are combined.

[0018] The power cable 14 includes a main line 14A and a plurality of branch lines 14B. A relay cable 21 is connected to any one of the plurality of branch lines 14B via a connector 14C, and a constant power supply, an ACC power supply, a ground, an external terminal on the vehicle side, the power box 40, and the like are connected to the other branch lines 14B. RCA terminals 15A, 15B, 15C are provided on any several of the branch lines 14B.

[0019] The power cable 14 supplies electric power to the in-vehicle device 10 through a power line from a constant power supply or an ACC power supply, and receives operation signals of a turn signal, a brake, and a shift lever, driving information such as vehicle speed, and the like from a control device on the vehicle side and transmits them to the in-vehicle device 10 through a signal line.

[0020] The trailer-side backup camera 20 is a rear-view camera that is installed at the rear part of a trailer T1 and captures images of the area behind the trailer T1. The trailer-side backup camera 20 is an analog video camera that outputs analog video signals. In the present embodiment, the type (standard) of the video signal of the trailer-side backup camera 20 conforms to NTSC (National Television System Committee). One connection terminal of a relay cable 21 is connected to an external terminal of the trailer-side backup camera 20, and the other connection terminal of the relay cable 21 is connected to a branch line 14B of the power cable 14 via a connector 14C. The trailer-side backup camera 20 may be provided with a shutter for lens protection.

[0021] A connector 21C is provided at an intermediate portion of the relay cable 21, and the relay cable 21 is divided into two parts with the connector 21C as a boundary. The relay cable 21 may alternatively be divided into three parts. The connector 21C is detachable outside the vehicle compartment. When a tractor T0 and the trailer T1 are coupled (FIG. 1), the connector 21C is connected, so that the trailer-side backup camera 20 is connected to the in-vehicle device 10 via the relay cable 21 and the power cable 14. In contrast, when the trailer T1 and the tractor T0 are disconnected (FIG. 2), the connector 21C is separated, so that the connection between the trailer-side backup camera 20 and the in-vehicle device 10 is cut off. It is not essential for the trailer-side backup camera 20 to be an analog video camera, and the trailer-side backup camera 20 may alternatively be a digital video camera.

[0022] The relay cable 21 is a composite cable combining signal lines and power lines. The power cable 14 and the relay cable 21 supply power to the trailer-side rearview camera 20 via the power lines from the constant power supply or ACC power supply connected to the in-vehicle unit 10. The relay cable 21 and the power cable 14 transmit analog video signals from the trailer-side rearview camera 20 to the in-vehicle unit 10 via the signal lines. In addition, the power cable 14 and the relay cable 21 transmit control signals, such as shutter opening and closing, from the in-vehicle unit 10 to the trailer-side rearview camera 20 via the signal lines.

[0023] The tractor-side rear camera 30 is installed at the rear of the tractor T0 and is a rear camera that captures the area behind the tractor T0. The tractor-side rear camera 30 is a digital video camera that converts digital video signals to analog video signals for output. In this embodiment, the type (standard) of the video signal of the tractor-side rear camera 30 is HD-TVI (High Definition Transport Video Interface). The external terminal of the tractor-side rear camera 30 is connected to the external terminal 41A of the power box 40 via a relay cable 31. The tractor-side rear camera 30 is equipped with a shutter for lens protection. Note that it is not mandatory for the tractor-side rear camera 30 to be a digital video camera; it may also be an analog video camera. Furthermore, it is not mandatory for the transmission method between the tractor-side rear camera 30 and the on-board unit 10 to be analog transmission; it may also be digital transmission.

[0024] The relay cable 31 is a composite cable that combines signal lines and power lines. The relay cable 31 supplies power to the tractor-side rear camera 30 from a constant power supply or ACC power supply connected to the power box 40 via the power line, and transmits analog video signals from the tractor-side rear camera 30 to the power box 40 via the signal line. The relay cable 31 also transmits control signals, such as shutter opening and closing, from the power box 40 to the tractor-side rear camera 30 via the signal line.

[0025] The power box 40 has the function of transmitting video signals from the tractor-side rearview camera 30 and the additional camera to the on-board unit 10, and the function of supplying power to the tractor-side rearview camera 30 and the additional camera. The power box 40 also has the function of transmitting control signals, such as shutter opening and closing, from the on-board unit 10 to the tractor-side rearview camera 30 and the additional camera.

[0026] The power box 40 includes an external terminal 41A for connecting the tractor-side rearview camera 30, external terminals 41B and 41C for connecting additional cameras, external terminals 42A, 42B, and 42C for connecting the on-board unit 10, and a terminal 43 for power connection. Terminal 43 is connected to constant power, ACC power, and ground.

[0027] One connector of the relay cable 31 is connected to external terminal 41A. The other connector of the relay cable 31 is connected to the external terminal of the tractor-side rearview camera 30. External terminals 41B and 41C are provided for connecting additional cameras, and the connectors of the relay cables connecting the additional cameras are connected to them.

[0028] One end of the relay cable 44 is connected to external terminal 42A. The other end of the relay cable 44 is connected to RCA terminal 15A. External terminals 41B and 41C are provided for connecting additional cameras, with external terminal 42B connected to RCA terminal 15B and external terminal 42C connected to RCA terminal 15C via relay cables.

[0029] The relay cable 44 includes at least a signal line. The relay cable 44 and the power cable 14 transmit the analog video signal output from the power box 40 to the on-board unit 10 via the signal line. The power cable 14 also transmits control signals, such as shutter opening and closing, generated by the on-board unit 10 to the trailer-side rear camera 20 via the signal line. The relay cable 31 also transmits control signals, such as shutter opening and closing, generated by the power box 40 to the tractor-side rear camera 30.

[0030] Figure 3 is a block diagram showing the schematic configuration of the in-vehicle unit 10 shown in Figures 1 and 2. As shown in this figure, the in-vehicle unit 10 includes a monitor 11, a front camera 16, a microphone 17, a GPS receiver 18, a remote control 19, a CPU (Central Processing Unit) 101, a memory 102, an interface (hereinafter referred to as I / F) 103, A / D conversion units 104A and 104B, a card interface (hereinafter referred to as card I / F) 105, an acceleration sensor 106, a remote control light receiver 107, and a power lamp 108. Note that an MCU (Micro Controller Unit) may be provided instead of the CPU 101.

[0031] The front camera 16 is integrated with the on-board unit 10 and is a digital video camera that captures the area in front of the tractor T0. The front camera 16 outputs a digital video signal to the I / F 103. In this embodiment, the type (standard) of the video signal from the front camera 16 is FHD (Full High Definition). Note that it is not essential to integrate the front camera 16 with the on-board unit 10; the front camera 16 may be placed separately at the top center of the front windshield.

[0032] The microphone 17 is integrated with the in-vehicle unit 10 and is a sound collector that collects sounds from the surrounding area of ​​the in-vehicle unit 10. The microphone 17 outputs a digital audio signal to the I / F 103. It is not mandatory to integrate the microphone 17 with the in-vehicle unit 10; the microphone 17 may be installed separately inside the vehicle.

[0033] The GPS receiver 18 is installed separately inside the vehicle and connected to the I / F 103 of the in-vehicle unit 10 by a cable, and receives GPS signals transmitted from GPS satellites (not shown). These GPS signals include GPS location information and GPS time information. Note that it is not mandatory to install the GPS receiver 18 separately inside the vehicle; it may be built into the in-vehicle unit 10.

[0034] The remote control 19 is a remote controller that is operated when switching the settings of the in-vehicle unit 10. Depending on the operation, the remote control 19 outputs a control signal to the I / F 103 via the remote control receiver 107.

[0035] The CPU 101 controls various parts of the in-vehicle unit 10, and in particular performs setting functions, video signal detection functions, video display functions, and recording / recording functions. The CPU 101 comprises a setting unit 101A, a video signal detection unit 101B, a video display unit 101C, and a recording / recording unit 101D.

[0036] The setting unit 101A displays a setting screen on the monitor 11 when a predetermined operation of the operation button 12 is performed, such as pressing and holding a predetermined operation button 12. Setting items include the vehicle number, driver ID, vehicle speed pulse, impact sensitivity of the acceleration sensor 106, setting whether or not to connect a camera (other than the tractor-side rearview camera 30), setting whether or not to connect a tractor-side rearview camera 30, setting the speed limit on general roads, setting the speed limit on highways, setting the volume of the microphone 17, setting the image quality, setting the type of video signal for connected cameras (other than the tractor-side rearview camera 30), and setting the type of video signal for the tractor-side rearview camera 30.

[0037] The settings screen displays setting items arranged vertically and horizontally, and the cursor is moved and an item is selected by operating the designated operation button 12. When the cursor is positioned over a setting item, the designated operation button 12 is operated to set that item.

[0038] In the settings for the connected cameras (other than the tractor-side rearview camera 30), the front camera 16 and the trailer-side rearview camera 20 are initially set as cameras to be connected, and each time the designated operation button 12 is operated, an additional camera is added to the connected cameras. In the settings for the tractor-side rearview camera 30, it is initially set to "off," and is set to "on" when the designated operation button 12 is operated.

[0039] Figure 4 is a front view of the in-vehicle unit 10 shown in Figure 1, etc. The upper part of the monitor 11 in this figure displays the camera image, and the lower part of the monitor 11 displays the settings screen. "External Camera Settings" is a setting item for the type of video signal of the trailer-side backup camera 20, and "Other Camera Settings" is a setting item for the type of video signal of the tractor-side backup camera 30.

[0040] In the external camera settings, the video signal type of the trailer-side rearview camera 20 is initially set to "HD-TVI," and switches between "NTSC" and "HD-TVI" each time the designated operation button 12 is operated. If the video signal type of the trailer-side rearview camera 20 does not match the video signal type of the trailer-side rearview camera 20 set in the in-vehicle unit 10, the image from the trailer-side rearview camera 20 will not be displayed on the monitor 11. In this embodiment, since the video signal type of the trailer-side rearview camera 20 is NTSC, the in-vehicle unit 10 sets the video signal type of the trailer-side rearview camera 20 to NTSC.

[0041] In other camera settings, the video signal type of the tractor-side rearview camera 30 is initially set to "NTSC," and switches between "HD-TVI" and "NTSC" each time the designated operation button 12 is operated. If the video signal type of the tractor-side rearview camera 30 does not match the video signal type of the tractor-side rearview camera 30 set in the on-board unit 10, the image from the tractor-side rearview camera 30 will not be displayed on the monitor 11. In this embodiment, since the video signal type of the tractor-side rearview camera 30 is HD-TVI, the on-board unit 10 sets the video signal type of the tractor-side rearview camera 30 to HD-TVI.

[0042] When a predetermined operation is performed on the operation button 12, such as pressing and holding a predetermined operation button 12, the setting unit 101A displays a message on the monitor 11 to confirm whether or not to save the setting changes. Depending on the selection of whether or not to save the setting changes, the setting unit 101A restarts or returns to the normal screen.

[0043] The setting unit 101A displays the operating mode setting screen on the monitor 11 when a predetermined operation of the operation button 12, such as a long press of the predetermined operation button 12, is performed while the ACC power is ON. Setting items include the linked operation of the reverse gear, turn signals, and remote control 19 operation and screen display, the display pattern of the basic screen, the monitor display, and the screen displayed when the turn signals are operated.

[0044] In the basic screen settings, the display pattern for monitor 11 when the reverse gear and turn signals are not operated can be set to full screen, dual screen, or triple screen. In the monitor display settings, the image from each camera can be set to normal or mirrored.

[0045] Figure 5 is a front view showing the on-board unit 10 as shown in Figure 1. This figure shows the monitor 11 during reverse gear operation. During reverse gear operation, the image from the trailer-side rearview camera 20 is displayed in full screen on the monitor 11. Conversely, if the trailer-side rearview camera 20 is not connected to the on-board unit 10, and the tractor-side rearview camera 30 is connected to the on-board unit 10 via the power box 40, the image from the tractor-side rearview camera 30 is displayed in full screen on the monitor 11 during reverse gear operation. If neither the trailer-side rearview camera 20 nor the tractor-side rearview camera 30 is connected to the on-board unit 10, a black screen is displayed on the monitor 11.

[0046] As shown in Figure 5, the monitor 11 displays a distance mark M. The monitor display settings during reverse gear operation include whether or not to display the distance mark M. It is possible to display the distance mark M, which indicates the distance from the rear of trailer T1, as an OSD (On Screen Display) display of the image from the trailer-side rear camera 20. On the other hand, it is not possible to display the distance mark, which indicates the distance from the rear of tractor T0, as an OSD display of the image from the tractor-side rear camera 30.

[0047] The video signal detection unit 101B shown in Figure 3 detects the video signal input to the CPU 101 via the I / F 103. The video display unit 101C displays the video on the monitor 11 based on the video signal detected by the video signal detection unit 101B.

[0048] When the trailer-side rearview camera 20 is connected to the in-vehicle unit 10, the analog video signal output from the trailer-side rearview camera 20 is converted into a digital video signal by the A / D conversion unit 104B, input to the CPU 101 via the I / F 103, and detected by the video signal detection unit 101B. The video display unit 101C displays the video from the trailer-side rearview camera 20 on the monitor 11 based on the video signal detected by the video signal detection unit 101B.

[0049] When the tractor-side rearview camera 30 is connected to the on-board unit 10 via the power box 40, the analog video signal output from the tractor-side rearview camera 30 is converted to a digital video signal by the A / D conversion unit 104A and detected by the video signal detection unit 101B via the I / F 103. When the trailer-side rearview camera 20 is connected to the on-board unit 10 and the video signal detection unit 101B detects the video signal from both the trailer-side rearview camera 20 and the tractor-side rearview camera 30, the video display unit 101C displays the video from the trailer-side rearview camera 20 on the monitor 11 based on the video signal detected by the video signal detection unit 101B. In contrast, if the connection between the trailer-side rear camera 20 and the in-vehicle unit 10 is interrupted and only the video signal from the tractor-side rear camera 30 is detected by the video signal detection unit 101B, the video display unit 101C will display the video from the tractor-side rear camera 30 on the monitor 11 based on the video signal from the tractor-side rear camera 30 detected by the video signal detection unit 101B.

[0050] The recording / recording unit 101D continuously records video captured by the front camera 16, the trailer-side rear camera 20, the tractor-side rear camera 30, and additional cameras onto the external recording medium 105C, or when the acceleration sensor 106 detects an impact. The recording / recording unit 101D also continuously records audio collected by the microphone 17 onto the external recording medium 105C, or when the acceleration sensor 106 detects an impact. Furthermore, the recording / recording unit 101D continuously records GPS location information onto the external recording medium 105C, or when the acceleration sensor 106 detects an impact.

[0051] Memory 102 is a non-volatile memory that stores programs executed by the CPU 101. Examples of programs executed by the CPU 101 include those for setting functions, video signal detection functions, video display functions, and recording / recording functions. Memory 102 also stores various setting information, such as the type of video signal for each camera.

[0052] I / F103 is connected to the operation button 12, front camera 16, microphone 17, GPS receiver 18, CPU 101, A / D converters 104A and 104B, acceleration sensor 106, remote control receiver 107, and external terminals. Various signals output from the operation button 12, front camera 16, microphone 17, GPS receiver 18, remote control 19, trailer-side rear camera 20, tractor-side rear camera 30, and the vehicle-side I / F are input to the CPU 101 via I / F103.

[0053] The A / D converter 104A converts analog video signals input from RCA terminals 15A, 15B, and 15C into digital video signals and outputs them to the I / F 103. The A / D converter 104B converts video signals input from connector 14C into digital video signals and outputs them to the I / F 103. The card I / F 105 is used to insert and remove external recording media 105C such as an SD card. The external recording media 105C inserted into the card I / F 105 records camera video, microphone audio, vehicle driving information, GPS location information, etc.

[0054] The acceleration sensor 106 is built into the in-vehicle unit 10 and detects the acceleration applied to the vehicle and outputs a detection signal to the I / F 103. The remote control receiver 107 is located near the monitor 11 and receives communication light such as infrared light output from the remote control 19 and outputs a control signal to the I / F 103. The power lamp 108 is located near the monitor 11 and lights up red or blue depending on the setting status of the in-vehicle unit 10, or blinks red when an error occurs.

[0055] Here, as shown in Figure 1, when the tractor T0 and trailer T1 are connected, the connector 21C of the relay cable 21 is connected, and the trailer-side rearview camera 20 is connected to the on-board unit 10 via the relay cable 21 and the power cable 14. The trailer-side rearview camera 20 outputs an analog video signal to the on-board unit 10 via the relay cable 21 and the power cable 14 while the power of the on-board unit 10 is ON. On the other hand, as shown in Figures 1 and 2, both when the tractor T0 and trailer T1 are connected and disconnected, the tractor-side rearview camera 30 is connected to the on-board unit 10 via the relay cable 31, the power box 40, the relay cable 44 and the power cable 14. The tractor-side rearview camera 30 outputs an analog video signal to the on-board unit 10 via the relay cable 31, the power box 40, the relay cable 44 and the power cable 14 while the power of the on-board unit 10 is ON.

[0056] When the tractor T0 and trailer T1 are coupled, the video signal output from the trailer-side rear camera 20 as an analog video signal, converted to a digital video signal by the A / D converter 104B and input to the CPU 101, and the video signal output from the tractor-side rear camera 30 as an analog video signal, converted to a digital video signal by the A / D converter 104A and input to the CPU 101 are detected by the video signal detection unit 101B. The video display unit 101C displays the image of the rear of the trailer T1 on the monitor 11 based on the video signal output from the trailer-side rear camera 20 and detected by the video signal detection unit 101B.

[0057] In contrast, when the tractor T0 and trailer T1 are disconnected, the tractor-side rear camera 30 outputs an analog video signal, which is converted into a digital video signal by the A / D converter 104A and input to the CPU 101. This video signal is then detected by the video signal detection unit 101B. Based on the video signal detected by the video signal detection unit 101B, the video display unit 101C displays the image of the area behind the tractor T0 on the monitor 11.

[0058] In other words, if the connection between the trailer-side rearview camera 20 and the on-board unit 10 is interrupted, the video display unit 101C switches the image of the area behind the truck displayed on the monitor 11 from the image captured by the trailer-side rearview camera 20 to the image captured by the tractor-side rearview camera 30.

[0059] As described above, in this embodiment, the in-vehicle unit 10 is connected to a trailer-side rearview camera 20 installed on the trailer T1 via a detachable connector 21C, and to a tractor-side rearview camera 30 installed on the tractor T0, and displays images on the monitor 11 based on the video signals from the trailer-side rearview camera 20 or the tractor-side rearview camera 30.

[0060] If the CPU 101 of the in-vehicle unit 10 is receiving a video signal from the trailer-side rearview camera 20, it displays the video on the monitor 11 based on the video signal received from the trailer-side rearview camera 20. Conversely, if the CPU 101 is not receiving a video signal from the trailer-side rearview camera 20 but is receiving a video signal from the tractor-side rearview camera 30, it displays the video on the monitor 11 based on the video signal received from the tractor-side rearview camera 30.

[0061] This allows the image from the trailer-side rearview camera 20 to be displayed on the in-cabin monitor 11 when the tractor T0 and trailer T1 are connected, and the image from the tractor-side rearview camera 30 to be displayed on the in-cabin monitor 11 when the tractor T0 and trailer T1 are disconnected. In this case, there is no need to switch connectors to the power box 40 which is housed deep inside the cabin, nor is there any need to install two monitors, one for the tractor T0 and one for the trailer T1. This avoids increased workload for the driver and electrical contractors, increased costs, and obstruction of the driver's view.

[0062] Furthermore, the CPU 101 of the in-vehicle unit 10 according to this embodiment receives setting information regarding the video signal specifications of the trailer-side rearview camera 20 and the tractor-side rearview camera 30, and stores the received setting information in the memory 102. The CPU 101 receives a video signal from the trailer-side rearview camera 20, and if the video signal specifications of the trailer-side rearview camera 20 included in the setting information stored in the memory 102 match the video signal specifications received from the trailer-side rearview camera 20, it displays an image on the monitor 11 based on the video signal received from the trailer-side rearview camera 20. Conversely, if the CPU 101 has not received a video signal from the trailer-side rearview camera 20, but has received a video signal from the tractor-side rearview camera 30, and if the video signal specifications of the tractor-side rearview camera 30 included in the setting information stored in the memory 102 match the video signal specifications received from the tractor-side rearview camera 30, it displays an image on the monitor 11 based on the video signal received from the tractor-side rearview camera 30.

[0063] Even if the video signal standards of the trailer-side rearview camera 20 and the tractor-side rearview camera 30 are different, as long as the initial settings for both standards are configured, when the tractor T0 and trailer T1 are connected, the image from the trailer-side rearview camera 20 can be displayed on the monitor 11 inside the vehicle, and when the tractor T0 and trailer T1 are disconnected, the image from the tractor-side rearview camera 30 can be displayed on the monitor 11 inside the vehicle.

[0064] Furthermore, the CPU 101 of the in-vehicle unit 10 according to this embodiment receives a video signal from the trailer-side rear camera 20 and also receives a video signal from the tractor-side rear camera 30, and displays the video on the monitor 11 based on the video signal received from the trailer-side rear camera 20. As a result, when the tractor T0 and trailer T1 are coupled, the video from the trailer-side rear camera 20 can be displayed on the monitor 11 inside the vehicle, allowing the driver to check the image behind the trailer T1.

[0065] Furthermore, in the rearview camera system 1 according to this embodiment, a monitor 11 and a CPU 101 are provided in the on-board unit 10, and the CPU 101 provided in the on-board unit 10 switches between the video from the trailer-side rearview camera 20 and the video from the tractor-side rearview camera 30. As a result, the tractor-side rearview camera 30 can be connected to the on-board unit 10 via a power box 40 which does not have a CPU. Therefore, a rearview camera system 1 can be constructed with simple and low-cost additional on-board units.

[0066] Figures 6 and 7 show schematic diagrams of a rearview camera system 100 according to another embodiment of the present invention. The rearview camera system 100 shown in these figures is used in practice as a vehicle rear-view device for trucks. Components similar to those in the above-described embodiments are denoted by the same reference numerals, and the descriptions of the above-described embodiments will be used accordingly.

[0067] The rearview camera system 100 comprises an in-vehicle unit 10, a trailer-side rearview camera 120, a tractor-side rearview camera 30, and a camera selector 140. The trailer-side rearview camera 120 is a digital video camera installed at the rear of the trailer T1, and it captures the area behind the trailer T1 and outputs a digital video signal. In this embodiment, the type (standard) of the video signal from the trailer-side rearview camera 120 is HD-TVI.

[0068] The camera selector 140 has the function of transmitting video signals from the trailer-side rearview camera 120, the tractor-side rearview camera 30, and additional cameras to the on-board unit 10, and the function of supplying power to the trailer-side rearview camera 120, the tractor-side rearview camera 30, and additional cameras. The camera selector 140 also has the function of transmitting control signals such as shutter opening and closing to the trailer-side rearview camera 120, the tractor-side rearview camera 30, and additional cameras, and the function of displaying the video captured by the trailer-side rearview camera 120 and the tractor-side rearview camera 30 on the monitor 11 of the on-board unit 10. The video from the cameras displayed on the monitor 11 can be switched arbitrarily by operating the on-board unit 10 or the camera selector 140.

[0069] The camera selector 140 includes external terminals 141A, 141B, and 141C for connecting cameras such as the trailer-side rearview camera 120, an external terminal 142 for connecting the camera selector 140 to the in-vehicle unit 10, a terminal 143 for power connection, an external terminal 145 for connecting the camera selector 140 to the external terminal of another monitor (not shown), and an external terminal 146 for remote control connection. Terminal 143 is connected to constant power, ACC power, and ground. In this embodiment, nothing is connected to external terminals 145 and 146.

[0070] One end of the relay cable 121 is connected to the external terminal of the trailer-side rearview camera 120, and the other end of the relay cable 121 is connected to the external terminal 141A of the camera selector 140.

[0071] A connector 121C is provided in the middle of the relay cable 121, dividing the relay cable 121 into two at the connector 121C. Alternatively, the relay cable 121 may be divided into three sections. The connector 121C is detachable from outside the vehicle. When the tractor T0 and trailer T1 are connected (Figure 6), the connector 121C is connected, connecting the trailer-side rearview camera 120 to the camera selector 140 via the relay cable 121. Conversely, when the trailer T1 and tractor T0 are disconnected (Figure 7), the connector 121C is cut, severing the connection between the trailer-side rearview camera 120 and the camera selector 140.

[0072] The relay cable 121 is a composite cable that combines signal lines and power lines. The relay cable 121 supplies power to the trailer-side rear camera 120 from a constant power supply or ACC power supply connected to the camera selector 140 via the power line. The relay cable 121 transmits digital video signals from the trailer-side rear camera 120 to the camera selector 140 via the signal line. The relay cable 121 also transmits control signals, such as shutter opening and closing, from the camera selector 140 to the trailer-side rear camera 120 via the signal line.

[0073] One end of the relay cable 31 is connected to the external terminal of the tractor-side rearview camera 30, and the other end of the relay cable 31 is connected to the external terminal 141B of the camera selector 140.

[0074] One connection terminal of the relay cable 144 is connected to the external terminal 142 of the camera selector 140, and the other connection terminal of the relay cable 144 is connected to the branch line 14B of the power cable 14 via connector 14C. The relay cable 144 is equipped with at least a signal line. The relay cable 144 and the power cable 14 transmit the digital video signal output from the camera selector 140 to the in-vehicle unit 10 via the signal line. The relay cable 144 and the power cable 14 also transmit the operation signals of the camera selector 140's remote control (not shown) to the in-vehicle unit 10 from the camera selector 140. In addition, the relay cables 31 and 121 transmit control signals such as shutter opening and closing from the camera selector 140 to the tractor-side rear camera 30 or the trailer-side rear camera 120 via the signal line.

[0075] Figure 8 is a block diagram showing the schematic configuration of the in-vehicle unit 10 and camera selector 140 shown in Figures 6 and 7. As shown in this figure, the camera selector 140 includes a CPU 1401, a memory 1402, and an I / F 1403.

[0076] The CPU 1401 controls the camera selector 140 and the various parts of the in-vehicle unit 10, and in particular performs the video signal detection function and the video signal output function. The CPU 1401 includes a video signal detection unit 1401B and a video signal output unit 1401C. The CPU 101 of the in-vehicle unit 10 controls the various parts of the in-vehicle unit 10, and in particular performs the setting function, video signal detection function, display function, and recording / recording function. The CPU 101 includes a setting unit 101A, a video signal detection unit 101B, a video display unit 101C, and a recording / recording unit 101D.

[0077] The setting unit 101A displays a setting screen on the monitor 11 when a predetermined operation of the operation button 12 is performed, such as pressing and holding a predetermined operation button 12. Setting items include the vehicle number, driver ID, vehicle speed pulse, impact sensitivity of the acceleration sensor 106, setting whether or not to connect cameras (other than the tractor-side rearview camera 30), setting whether or not to connect the tractor-side rearview camera 30, setting the speed limit on general roads, setting the speed limit on highways, setting the volume of the microphone 17, setting the image quality, setting the type of video signal for connected cameras (other than the tractor-side rearview camera 30), and setting the type of video signal for the tractor-side rearview camera 30.

[0078] Here, the type of video signal from the trailer-side rearview camera 120 and the tractor-side rearview camera 30 is limited to "HD-TVI". Therefore, it is not necessary to set the type of video signal from the trailer-side rearview camera 120 and the tractor-side rearview camera 30. Alternatively, the signal type from the trailer-side rearview camera 120 and the tractor-side rearview camera 30 may be limited to "NTSC".

[0079] The video signal detection unit 1401B detects the video signal input to the CPU 1401 via the I / F 1403. The video signal output unit 1401C displays the video on the monitor 11 based on the video signal detected by the video signal detection unit 1401B.

[0080] When the trailer-side rearview camera 120 is connected to the camera selector 140, the digital video signal output from the trailer-side rearview camera 120 is input to the CPU 1401 via the I / F 1403 and detected by the video signal detection unit 1401B. The video signal output unit 1401C displays the video from the trailer-side rearview camera 120 on the monitor 11 based on the digital video signal detected by the video signal detection unit 1401B.

[0081] When the tractor-side rearview camera 30 is connected to the camera selector 140, the digital video signal output from the tractor-side rearview camera 30 is detected by the video signal detection unit 1401B via the I / F 1403. When the trailer-side rearview camera 120 and the tractor-side rearview camera 30 are connected to the camera selector 140, and the video signal detection unit 1401B detects video signals from both the trailer T1 and the tractor T0, the video signal output unit 1401C displays the image of the area behind the trailer T1 on the monitor 11 based on the video signal from the trailer T1 detected by the video signal detection unit 1401B. In contrast, if the connection between the trailer-side rear camera 120 and the camera selector 140 is interrupted and only the video signal from the tractor T0 side is detected by the video signal detection unit 1401B, the video signal output unit 1401C will display the image of the area behind the tractor T0 on the monitor 11 based on the video signal from the tractor T0 side detected by the video signal detection unit 1401B.

[0082] Memory 1402 is a non-volatile memory that stores programs executed by CPU 1401. Examples of programs executed by CPU 1401 include programs that perform video signal detection and video signal output functions.

[0083] I / F1403 is connected to the CPU1401, the trailer-side rearview camera 120, the tractor-side rearview camera 30, and the I / F103 of the on-board unit 10. Video signals from the trailer-side rearview camera 120 and the tractor-side rearview camera 30 are input to the CPU1401 via I / F103. Control signals output from the camera selector 140's I / F1403, and operation signals from the camera selector 140's remote control are input to the CPU101 via the on-board unit 10's I / F103.

[0084] Here, as shown in Figure 6, when the tractor T0 and trailer T1 are connected, the connector 121C of the relay cable 121 is connected, and the trailer-side rearview camera 120 is connected to the on-board unit 10 via the relay cable 121, camera selector 140, relay cable 144, and power cable 14. The trailer-side rearview camera 120 outputs a digital video signal to the on-board unit 10 via the relay cable 121, camera selector 140, relay cable 144, and power cable 14 while the power of the on-board unit 10 is ON. On the other hand, as shown in Figures 6 and 7, when the tractor T0 and trailer T1 are connected and disconnected, the tractor-side rearview camera 30 is connected to the on-board unit 10 via the relay cable 31, camera selector 140, relay cable 144, and power cable 14. While the power to the on-board unit 10 is ON, the tractor-side rearview camera 30 outputs a digital video signal to the on-board unit 10 via the relay cable 31, camera selector 140, relay cable 144, and power cable 14.

[0085] When the tractor T0 and trailer T1 are coupled, the digital video signal output from the trailer-side rearview camera 120 and input to the CPU 1401, and the digital video signal output from the tractor-side rearview camera 30 and input to the CPU 1401 are detected by the video signal detection unit 1401B. The video signal output unit 1401C displays the image of the area behind the trailer T1 on the monitor 11 based on the digital video signal output from the trailer-side rearview camera 120 and detected by the video signal detection unit 1401B.

[0086] In contrast, when the tractor T0 and trailer T1 are disconnected, the digital video signal output from the tractor-side rearview camera 30 and input to the CPU 1401 is detected by the video signal detection unit 1401B. The video signal output unit 1401C displays the image of the area behind the tractor T0 on the monitor 11 based on the digital video signal detected by the video signal detection unit 1401B.

[0087] In other words, if the connection between the trailer-side rearview camera 120 and the on-board unit 10 is interrupted, the video signal output unit 1401C switches the image of the area behind the truck displayed on the monitor 11 from the image captured by the trailer-side rearview camera 120 to the image captured by the tractor-side rearview camera 30.

[0088] As described above, in the rearview camera system 100 according to this embodiment, the monitor 11 is provided in the in-vehicle unit 10, and the CPU 1401 and memory 1402 are provided in the camera selector 140. The CPU 1401 provided in the camera selector 140 switches between the video from the trailer-side rearview camera 120 and the video from the tractor-side rearview camera 30.

[0089] Although the present invention has been described above based on the embodiments described above, the present invention is not limited to the embodiments described above, and modifications may be made, or the technologies of the embodiments or publicly known technologies may be combined, without departing from the spirit of the present invention.

[0090] For example, in the embodiment described above, the "in-vehicle unit" may consist of a single in-vehicle unit 10, or it may consist of an in-vehicle unit 10 and a camera selector 140. However, the number of devices that make up the "in-vehicle unit" and which devices contain the "display unit," "control unit," "reception unit," and "storage unit" can be set as appropriate. [Explanation of Symbols]

[0091] 1: Rearview camera system 10: Onboard equipment 11: Monitor (display unit) 20: Trailer-side rearview camera 21C: Connector (connection terminal) 30: Tractor-side rearview camera 100: Rearview camera system 101: CPU (Control Unit, Reception Unit) 102: Memory (storage unit) 120: Trailer-side backup camera 121C: Connector (connection terminal) 140: Camera Selector (In-vehicle unit) 1401: CPU (Control Unit, Reception Unit) 1402: Memory (storage unit) T0: Tractor T1: Trailer

Claims

1. An in-vehicle device that displays an image based on the video signal from the trailer-side rearview camera or the tractor-side rearview camera, wherein a trailer-side rearview camera installed on the trailer is connected via a detachable connector terminal, and a tractor-side rearview camera installed on the tractor is also connected, A display unit that displays images, A control unit that, when receiving a video signal from the trailer-side rearview camera, displays an image on the display unit based on the video signal received from the trailer-side rearview camera, and when not receiving a video signal from the trailer-side rearview camera, displays an image on the display unit based on the video signal received from the tractor-side rearview camera. An in-vehicle device equipped with this feature.

2. A receiving unit that receives setting information for the video signal specifications of the trailer-side rearview camera and the video signal specifications of the tractor-side rearview camera, A storage unit that stores the setting information received by the reception unit and Equipped with, The control unit, The system receives a video signal from the trailer-side rearview camera, and if the specifications of the video signal from the trailer-side rearview camera included in the setting information stored in the storage unit match the specifications of the video signal received from the trailer-side rearview camera, the system displays a video on the display unit based on the video signal received from the trailer-side rearview camera. If no video signal is received from the trailer-side rearview camera, but a video signal is received from the tractor-side rearview camera, and the specifications of the video signal from the tractor-side rearview camera included in the setting information stored in the memory unit match the specifications of the video signal received from the tractor-side rearview camera, then the display unit will display a video based on the video signal received from the tractor-side rearview camera. The in-vehicle device according to claim 1.

3. When the control unit receives a video signal from the trailer-side rearview camera and also receives a video signal from the tractor-side rearview camera, it causes the display unit to display a video based on the video signal received from the trailer-side rearview camera. The in-vehicle device according to claim 1 or 2.

4. A program for operating an in-vehicle device that displays an image based on the video signal from the trailer-side rearview camera or the tractor-side rearview camera, wherein a trailer-side rearview camera installed on the trailer is connected via a detachable connector terminal, and a tractor-side rearview camera installed on the tractor is also connected, A program for performing the following processes: when a video signal is received from the trailer-side rear camera, the program displays an image on the display unit of the in-vehicle device based on the video signal received from the trailer-side rear camera; and when a video signal is not received from the trailer-side rear camera, but a video signal is received from the tractor-side rear camera, the program displays an image on the display unit based on the video signal received from the tractor-side rear camera.

5. A trailer-side rearview camera installed on the trailer, A rearview camera installed on the tractor, The trailer-side rearview camera is connected via a detachable connector, the tractor-side rearview camera is connected, and an in-vehicle unit that displays an image based on the video signal from the trailer-side rearview camera or the tractor-side rearview camera. A rear camera system equipped with, The aforementioned in-vehicle device is A display unit that displays images, A control unit that, when receiving a video signal from the trailer-side rearview camera, displays an image on the display unit based on the video signal received from the trailer-side rearview camera, and when not receiving a video signal from the trailer-side rearview camera, displays an image on the display unit based on the video signal received from the tractor-side rearview camera. A rearview camera system equipped with this feature.

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