JP2004112329A - Imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup system by which excellent photographing can be executed while preventing an electric power balance from deteriorating. <P>SOLUTION: The image pickup system 1 is provided with a CCD 2 installed inside a vehicle cabin for taking images outside the vehicle through a windshield glass. A fogging state of a windshield glass 11 is detected on the basis of a photographed image to be obtained by photographing with the CCD 2. A temperature of a glass part in an image pickup region of the CCD 2 is risen by a heating wire 7 on the basis of the fogging state. By this, it is possible to prevent the power balance from deteriorating by suppressing waste operations of the heating wire 7 as a temperature rising means of the windshield glass 11. As a result, the excellent photographing without the fogging state to the windshield glass 11 can be realized. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an imaging system mounted on a vehicle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an imaging system mounted on a vehicle, there is known an apparatus for photographing the outside of a vehicle using a camera head including a lens, a CCD, and the like, as described in Japanese Patent Application Laid-Open No. 4-286280. In this device, a heater is provided on the protective glass on the front surface of the lens, and when the temperature falls below a predetermined temperature, the heater is turned on. In this way, the protective glass is heated by the heater to remove dew or icing that occurs on the protective glass, thereby preventing photographing failure due to dew or the like.
[0003]
[Patent Document 1]
JP-A-4-286280
[Problems to be solved by the invention]
However, such an imaging system has a problem that heating by a heater cannot be appropriately performed. That is, when the operation of the heater is controlled according to the temperature condition, the heater is always turned on at a predetermined temperature or lower. In winter or cold regions, the heater is turned on irrespective of dew condensation or the like, and the energization time of the heater becomes extremely long, which may deteriorate the power balance.
Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide an imaging system capable of performing good photographing while preventing a power balance from deteriorating.
[0005]
[Means for Solving the Problems]
In other words, the imaging system according to the present invention detects the fogging state of the glass based on a captured image obtained by imaging of the imaging unit in an imaging system provided with an imaging unit that is installed in the vehicle interior and captures the outside of the vehicle through the glass. It is characterized by comprising a detecting means and a temperature raising means for raising a temperature of a glass portion in an imaging region of the imaging means based on the cloudy state.
[0006]
According to the present invention, the fogging state of the glass is detected based on the captured image of the imaging means, and the temperature of the glass is raised based on the fogging state, whereby the temperature raising means can be operated according to the fogging state of the glass. it can. For this reason, when removing the fogging of the glass, it is possible to prevent the operation of the temperature raising means when the fogging of the glass does not occur, thereby enabling good photographing while preventing the energy balance from deteriorating. Also, there is no need to provide a dedicated sensor for detecting glass fogging, so that cost reduction and size reduction can be achieved.
[0007]
Further, the imaging system according to the present invention, in an imaging system provided with an imaging unit that is installed in the vehicle interior and captures an image of the outside of the vehicle through the glass, starts operating together with the operation of a defroster that prevents fogging of the glass, and operates in an imaging region of the imaging unit. It is characterized by comprising a temperature raising means for raising the temperature of the glass portion.
Further, in the imaging system according to the present invention, in an imaging system provided with an imaging unit installed in a vehicle interior and imaging the outside of the vehicle through the glass, the operation starts together with the operation of the fogging prevention unit for preventing the other glass different from the glass from fogging. And a temperature raising means for raising the temperature of the glass portion in the imaging region of the imaging means.
[0008]
According to these inventions, by starting the operation of the temperature raising means together with the operation of the defroster for preventing the fogging of the glass, the operation of the temperature raising means when the fogging of the glass does not occur is suppressed, and the energy balance is deteriorated. It is possible to take a good image while preventing the image. Also, there is no need to provide a dedicated sensor for detecting glass fogging, so that cost reduction and size reduction can be achieved.
[0009]
Further, the imaging system according to the present invention is characterized in that the above-mentioned heating means is a hot wire provided on glass. Further, according to these inventions, the imaging system according to the present invention is characterized in that the above-mentioned temperature raising means starts operating together with the operation of the imaging means and stops after a predetermined time, before detecting the fogging of the glass. The temperature of the glass can be raised.
[0010]
Further, in the imaging system according to the present invention, it is desirable that the cover is provided with the photographing means housed therein and the opening facing the surface of the glass. Further, it is desirable that the imaging system according to the present invention is used for a visual recognition support system that supports a driver's visual recognition when the vehicle travels at night.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.
(First embodiment)
1 and 2 are explanatory diagrams of an imaging system according to the first embodiment.
[0012]
As shown in FIG. 1, an imaging system 1 according to the present embodiment is a system that is installed in a vehicle interior and captures an image outside the vehicle through a glass 11. In the present embodiment, a case will be described in which the present invention is applied to a visual recognition support system that performs visual recognition support of a driver when a vehicle travels at night.
The imaging system 1 includes a camera main body 3 that performs photographing outside the vehicle. The camera body 3 is installed in a vehicle interior, and has a built-in CCD (Charge-Coupled Device) 2. The CCD 2 is an imaging unit that captures an image of the outside of the vehicle through the glass 11. A photographing optical system 4 is provided in front of the CCD 2, and a photographed image enters the CCD 2 through the photographing optical system 4. As the glass 11, for example, a front windshield or the like corresponds.
[0013]
As the camera body 3, for example, a camera body having sensitivity to near infrared light is used. By arranging the visible light cut filter in the photographing optical system 4 in front of the CCD 2, it becomes possible to visualize near infrared components. Here, the near-infrared light means light having a wavelength of 780 to 1500 nm. The heating wire 7 is provided in a photographing area of the CCD 2 on the glass 11.
The output side of the camera body 3 is connected to the system control unit 21. A video signal obtained by photographing the camera body 3 is input to the system control unit 21. The system control unit 21 controls the entire system, and includes, for example, a CPU, a ROM, a RAM, an input signal circuit, an output signal circuit, a power supply circuit, and the like.
The imaging system 1 includes a near-infrared light projector 22. The near-infrared light projector 22 is a light projecting unit that emits near-infrared light in front of the vehicle, and receives light from the system control unit 21 and is controlled to emit light. The near-infrared light projector 22 is configured to project near-infrared light in an irradiation range corresponding to, for example, a high (Hi) beam of a headlight.
Further, the imaging system 1 is provided with a display unit 23. The display unit 23 is a display unit that displays a captured image of the camera body 3 and is provided so that a driver can visually recognize the captured image. Further, the imaging system 1 is provided with a switch group 24 for operating on / off of the present system.
[0014]
As shown in FIG. 2, the camera body 3 is attached to the glass 11 via, for example, a bracket 5, and is installed so that the outside of the vehicle can be photographed through the glass 11. The camera body 3 has a built-in camera control unit 6. The camera control unit 6 functions as a control unit that performs control processing of the entire camera body 3 and also functions as a signal processing unit that performs signal processing for processing an output signal of the CCD 2.
Further, the camera control unit 6 also functions as a detection unit that detects a fogging state of the glass 11 based on a captured image obtained by capturing the image of the CCD 2. For example, the output signal of the CCD 2 is processed into a video signal, and the fogging state of the glass 11 is detected based on the level of flat noise in the video signal.
[0015]
A heating wire 7 is provided in a photographing area of the CCD 2 on the glass 11. The heating wire 7 is a temperature raising means for raising the temperature of the glass 11, and becomes a high temperature state to remove the fogging of the glass 11 and prevent the fogging. The heating wire 7 is connected to the above-described system control unit 21 (see FIG. 1) via the terminal 8 and the wiring 9, and operates based on detection of the fogging state of the glass 4 by the system control unit 21. The heating wire 7 is made of a thin conductive member, and generates heat when energized to be in a high temperature state. The heating wire 7 is provided in parallel, for example, in plurality.
[0016]
The imaging system 1 is provided with a cover 10 that covers the camera body 3. The cover 10 covers the CCD 2 serving as an imaging unit by covering the camera body 3. As the cover 10, for example, a cup-shaped one having an opening 10a is used. The cover 10 accommodates the camera body 3 and is arranged with the opening 10 a facing the surface of the glass 11. Thereby, the camera body 3 including the CCD 2 can be covered with the cover 10, thereby preventing the installation of the imaging system 1 from deteriorating the beauty of the interior of the vehicle. Further, the temperature-raised portion by the heat wire 7 can be covered with the cover 10, and fog removal and fogging prevention due to the high temperature of the glass 11 are promoted.
Next, the operation of the imaging system 1 according to the present embodiment will be described.
In FIG. 1, near-infrared light is emitted forward by the near-infrared light projector 22 when the vehicle is traveling at night. Thereby, near-infrared light is irradiated in front of the vehicle, and the front of the vehicle illuminated with near-infrared light is photographed by the camera body 3 having sensitivity in the near-infrared region.
A video signal is output from the camera body 3 to the system control unit 21. The system control unit 21 outputs a video signal to the display unit 23, and a captured image based on the video signal is displayed on the display unit 23. Since the captured image is displayed in a state where the near-infrared light is radiated, it becomes easier to detect a pedestrian or the like than when the driver of the vehicle visually recognizes the front of the vehicle with the naked eye. I can help. Further, since the light to be projected is near-infrared light, the influence on the driving of the oncoming vehicle is small.
Incidentally, the glass 11 may be fogged due to a temperature difference from the outside air, a humidity state, a low outside air temperature, or the like. For example, dew may adhere to the inner surface of the glass 11 or ice or frost may adhere to the outer surface of the glass 11. In such a case, since the CCD 2 captures the outside of the vehicle through the glass 11, the captured image becomes unclear due to the fogging of the glass 11.
On the other hand, in the imaging system 1, the fogging state of the glass 11 is detected based on the captured image captured by the CCD 2. For example, the output signal of the CCD 2 is processed by the camera control unit 6 into a video signal, and the level of flat noise in the video signal is detected. When the glass 11 becomes cloudy, the flat noise tends to increase. By detecting the level of the flat noise, it is possible to detect the cloudy state of the glass 11.
Then, when the flat noise of the video signal exceeds a predetermined level set in the camera control unit 6 in advance, it is determined that the glass 11 has fogged, and the heating wire 7 is energized. As a result, the heat rays 7 generate heat, the temperature of the glass 11 in the photographing area of the CCD 2 rises, and the fogging of the glass 11 is removed. Therefore, the photographing by the photographing system 1 can be appropriately performed.
[0017]
As described above, according to the imaging system 1 according to the present embodiment, the fogging state of the glass 11 is detected based on the captured image of the CCD 2, and the temperature of the glass 11 is raised based on the fogging state. The heating wire 7 serving as a temperature raising means can be operated according to the cloudy state. For this reason, when removing the fogging of the glass 11, it is possible to prevent the operation of the heating wire 7 when the fogging of the glass 11 is not generated, and to perform a good photographing while preventing the energy balance from deteriorating. In addition, there is no need to provide a dedicated sensor for detecting fogging of the glass 11, so that the cost and size of the system can be reduced.
[0018]
In the present embodiment, the heating wire 7 serving as a heating means is activated when the glass 11 becomes cloudy. In addition, the activation of the heating wire 7 is started together with the operation of the system, and the operation is stopped after a predetermined time. May be performed. In this case, regardless of the fogging state of the glass 11, the temperature of the glass 11 can be raised quickly, and the fogging of the glass 11 can be quickly removed. Further, fogging of the glass 11 can be prevented. That is, when the glass 11 starts to fog due to the heat generated by the operation of the system, it is possible to suppress the occurrence of the fogging in advance. Here, for example, 5 minutes is set as the predetermined time.
(Second embodiment)
Next, an imaging system according to a second embodiment will be described.
[0019]
The imaging system according to the present embodiment operates in response to the operation of the defroster that removes the fogging of the glass 11 from the heating wire 7 that is a heating unit. In the imaging system according to the first embodiment, the temperature of the glass 11 is raised by activating the heating wire 7 according to the fogging state of the glass 11 detected based on the captured image of the CCD 2. The imaging system according to the first embodiment is different from the imaging system according to the first embodiment in that the heating wire 7 is operated according to the operation of a defroster that is an external device.
[0020]
FIG. 3 shows a schematic configuration diagram of an imaging system 1a according to the present embodiment.
[0021]
As shown in the figure, a defroster 31 is connected to the system control unit 21. Thus, the start of operation of the defroster 31 can be detected by the system control unit 21. The defroster 31 blows hot air onto the inner surface of the glass 11 to remove or prevent fogging of the glass 11.
[0022]
When the glass 11 such as the front windshield becomes fogged, the driver of the vehicle operates the defroster 31 to secure the visibility, and removes the fog of the glass 11 with warm air. At this time, even when the glass 11 in front of the driver and the glass in front of the camera are integrated, the camera body 3 is covered with the cover 10, so that when the field of view in front of the driver is secured, the front of the camera is Fogging may not yet be removed.
[0023]
For this reason, even when the defroster 31 operates, it is necessary to remove or prevent the fogging of the glass portion in front of the camera body 3 by the heat wire 7. That is, according to the imaging system 1a, when the operation of the defroster 31 is performed, the start of the operation is detected by the system control unit 21, and the heating wire 7 is energized accordingly to generate heat. Thereby, the temperature of the glass 11 rises, and the fogging of the glass 11 is removed or prevented.
[0024]
As described above, according to the imaging system 1a according to the present embodiment, the defroster 31 is activated and the hot wire 7 is activated to raise the temperature of the glass 11, so that the temperature is raised according to the cloudy state of the glass 11. The heating wire 7 can be activated. For this reason, when removing the fogging of the glass 11, it is possible to prevent the operation of the heating wire 7 when the fogging of the glass 11 is not generated, and to perform a good photographing while preventing the energy balance from deteriorating. In addition, there is no need to provide a dedicated sensor for detecting fogging of the glass 11, so that the cost and size of the system can be reduced.
[0025]
In the present embodiment, as in the first embodiment, the operation of the heating wire 7 may be started together with the operation of the imaging system 1a, and the operation may be stopped after a predetermined time.
[0026]
Further, in the present embodiment, the imaging system 1a for starting the operation of the heating wire 7 together with the operation of the defroster 31 for removing or preventing the fogging of the glass 11 has been described, but the imaging system according to the present invention is limited to such. Instead, the imaging system may be an imaging system in which the heating wire 7 starts operating together with another glass different from the glass 11 to which the CCD 2 is attached, for example, a device for removing or preventing fogging of the rear window glass. In such an imaging system, as in the above-described imaging system 1a, by appropriately operating the heating wire 7, it is possible to perform good imaging while preventing the energy balance from deteriorating.
Further, in each of the above-described embodiments, the case where the heating wire 7 is used as the temperature raising means has been described. However, the imaging system according to the present invention is not limited to such a configuration, and the imaging system can raise the temperature of the glass 11. If so, a device other than the heating wire 7 may be used.
Furthermore, in each of the above-described embodiments, the case where the present invention is applied to the visual recognition support system that supports the driver's visual recognition during night driving of the vehicle has been described, but the imaging system according to the present invention is not limited to such. Instead, it may be used for other systems.
[0027]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an imaging system capable of performing good imaging while preventing deterioration of the power balance.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an imaging system according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of a camera body and the like in the imaging system of FIG. 1;
FIG. 3 is an explanatory diagram of an imaging system according to a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image pick-up system, 2 ... CCD (image pick-up means), 7 ... Hot wire (heating means), 11 ... Glass.

Claims (7)

In an imaging system provided with an imaging unit that is installed in the vehicle interior and captures the outside of the vehicle through the glass,
Detecting means for detecting a fogging state of the glass based on a captured image obtained by imaging of the imaging means,
Temperature-raising means for raising the temperature of the glass portion in the imaging region of the imaging means based on the cloudy state;
An imaging system comprising: In an imaging system provided with an imaging unit that is installed in the vehicle interior and captures the outside of the vehicle through the glass,
A heating unit that starts operating together with the operation of the defroster that prevents the fogging of the glass and that heats a glass part in an imaging region of the imaging unit;
An imaging system characterized by the above-mentioned. In an imaging system provided with an imaging unit that is installed in the vehicle interior and captures the outside of the vehicle through the glass,
The apparatus starts with the operation of fogging prevention means for preventing fogging of another glass different from the glass, and has a temperature raising means for raising a temperature of a glass part in an imaging region of the imaging means.
An imaging system characterized by the above-mentioned. The imaging system according to any one of claims 1 to 3, wherein the heating unit is a heating wire provided on the glass. The imaging system according to any one of claims 1 to 4, wherein the heating unit starts operating together with the operation of the imaging unit, and stops operating after a predetermined time. The imaging system according to any one of claims 1 to 5, further comprising a cover provided with the imaging unit housed therein and an opening directed to a surface of the glass. The imaging system according to any one of claims 1 to 6, wherein the imaging system is used in a visual assistance system that assists a driver in visually recognizing the vehicle when the vehicle travels at night.

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