JP2005159918A - In-vehicle camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-vehicle camera which controls the exposure or the white balance of the in-vehicle camera in accordance with an outer environment to further improve visibility. <P>SOLUTION: The in-vehicle camera is composed of: an optical lens system 1; an iris 2 for adjusting the quantity of incident light; an imaging device 3 for photo-electric transducing light from the optical lens system 1 into an imaging signal and outputting the signal; an exposure control part 4 for controlling the adjustment of the light quantity in the iris 2 and the light quantity of the imaging device 3; a signal processing part 5 for applying predetermined signal processing to the imaging signal, outputting an image signal, and outputting light quantity data corresponding to the light quantity of the imaging device 3; a white balance control part 6 for applying white balance correction control to the image data; at least one or more switches 9; a detection part 7 which is connected with the switches 9, detects on-states or off-states of the switches 9, and outputs a detecting signal; a storage part 11 for storing the setting of exposure or white balance or the like; and a control part 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to exposure control or white balance correction control of an in-vehicle camera.

  2. Description of the Related Art In recent years, attention has been focused on technologies for constructing various safety systems by mounting a vehicle-mounted camera on a vehicle. These technologies, for example, capture the road shape and obstacles around the vehicle with an in-vehicle camera, and output the captured image to a display device such as a liquid crystal installed in the vehicle to inform the driver of the danger during driving. It is something to be made.

  Patent Document 1 has been proposed as a technique related to these in-vehicle cameras.

  Patent Document 1 discloses a technique in which auxiliary light is mounted on a vehicle-mounted camera in order to display a vehicle periphery on a display device at night.

  An in-vehicle camera equipped with this auxiliary light has an image sensor that photoelectrically converts light into an image signal and outputs it, an exposure control unit that controls the amount of light incident on the light receiving surface of the image sensor, and a predetermined image signal. A signal processing unit that performs signal processing, converts the image data into standard image data, and outputs the image data to a display device; a white balance control unit that performs white balance correction control on the image data; and an object to be photographed in a dark environment such as at night And auxiliary light for irradiating light.

  Therefore, in a dark environment such as at night, the amount of light incident on the light receiving surface of the image sensor by the exposure control unit so that the subject can be displayed on the display device using auxiliary light. Thus, the image signal output from the image sensor is signal-processed by the signal processing unit and converted into image data, and the white balance control unit performs white balance correction control on the image data to the display device. Output and display the captured image.

In this way, in a dark environment, shooting is performed using auxiliary light, and the subject to be photographed is clearly displayed on the display device without being darkened through the above-described control such as exposure control and white balance correction control. be able to.

JP 2003-127771 A

  However, in the above-mentioned in-vehicle camera, sufficient consideration has not been given to shooting when light of a specific light source such as a headlight, a backlight, a direction indicator, and a stop lamp provided in a vehicle is irradiated on an object. First, when a subject to be illuminated with light of a specific light source is photographed, the photographed image of the subject to be photographed displayed on the display device is whiter compared to the subject to be illuminated with light of the particular light source. In addition, the problem of red or blue occurs, and it is not possible to perform photographing that clearly displays the photographing target on the display device.

  The present invention has been made in view of the above, and performs white balance correction control based on the difference in color temperature of light of a specific light source and exposure control corresponding to the type of light emission of the specific light source, so that the object to be photographed is optimal. An object of the present invention is to provide a vehicle-mounted camera that can display a captured image on a display device.

  The in-vehicle camera of the present invention corresponds to a detection unit that detects lighting of a light source of a vehicle, an imaging unit that photoelectrically converts incident light into an imaging signal, a white balance control unit that adjusts a white balance of the imaging signal, and the light source Storage means for storing the corrected data, and when the lighting of the light source of the vehicle is detected by the detecting means, white balance adjustment is performed using the correction data.

  The detecting means includes a means for detecting whether a plurality of light sources such as a headlight, a fog lamp, and a winker mounted on the vehicle are respectively turned on.

  In another vehicle-mounted camera according to the present invention, the storage means stores a plurality of correction data, and further includes a selection means for selecting arbitrary correction data from the plurality of correction data, and the detection means detects the vehicle. When lighting of a light source is detected, white balance adjustment is performed using the correction data selected by the selection means.

  In another on-vehicle camera of the present invention, the detecting means detects lighting of a plurality of light sources of a vehicle, and the storage means stores correction data corresponding to each of the plurality of light sources. When the lighting of any one of the plurality of light sources of the vehicle is detected by the detecting means, white balance adjustment is performed using the correction data corresponding to the light source that has detected the lighting.

  Another vehicle-mounted camera according to the present invention detects a light amount detecting means for detecting a received light amount for each of a plurality of areas on the light receiving surface of the image pickup means, and detects the presence of an area having a received light quantity greater than or equal to a predetermined value in the plurality of areas. And a white balance using the correction data when it is detected that the light source of the vehicle is turned on by the detecting means and that there is a region having a light receiving amount of a predetermined value or more. Adjustment is performed.

  Another vehicle-mounted camera according to the present invention further includes an exposure control unit that controls the amount of incident light of the imaging unit, and has a light reception amount that is equal to or greater than a predetermined value when the detection unit detects lighting of a vehicle light source. When it is detected that a region exists, the exposure control is performed based on an average received light amount of a region having a received light amount equal to or greater than the predetermined value.

  Another vehicle-mounted camera according to the present invention includes a light amount detection unit that detects a light reception amount for each of a plurality of regions on the light receiving surface of the imaging unit, and a light amount that is equal to or greater than a predetermined value in comparison with other adjacent regions in the plurality of regions. Means for detecting the presence or absence of a region having a difference, and when detecting the lighting of a light source of a vehicle by the detection unit and detecting that there is a region having a light amount difference of a predetermined value or more, The white balance adjustment is performed using the correction data.

  Another vehicle-mounted camera according to the present invention further includes an exposure control unit that controls an incident light amount of the imaging unit, and has a light amount difference equal to or greater than a predetermined value when the detection unit detects lighting of a light source of a vehicle. When it is detected that an area exists, the exposure control is performed based on an average received light amount of an area having a light amount difference equal to or greater than the predetermined value.

  Another vehicle-mounted camera according to the present invention detects a light amount detecting means for detecting a received light amount for each of a plurality of areas on the light receiving surface of the image pickup means, and detects the presence of an area having a received light quantity greater than or equal to a predetermined value in the plurality of areas. Means for detecting the presence / absence of a region having a light amount difference of a predetermined value or more compared to other adjacent regions in the plurality of regions, and an exposure control unit for controlling an incident light amount of the imaging unit. When detecting that the light source of the vehicle is turned on by the detecting means and detecting that there is a region having a light amount difference of a predetermined value or more, the average received light amount of the region having the light reception amount of the predetermined value or more is set. The exposure control is performed based on the above.

  Another vehicle-mounted camera according to the present invention detects a light amount detecting means for detecting a light receiving amount for each of a plurality of areas on the light receiving surface of the image pickup means, and detects the presence of a light receiving quantity equal to or less than a predetermined value in the plurality of areas. And an exposure control means for controlling the amount of incident light of the imaging means, and there is a region having a light reception amount equal to or less than a predetermined value when the detection means detects lighting of a light source of a vehicle. When detected, the exposure control is performed based on an average received light amount in a region other than a region having a received light amount equal to or less than the predetermined value.

  Thus, according to the in-vehicle camera of the present invention, it is possible to provide an in-vehicle camera that can optimally capture images corresponding to the light source.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an area diagram of the in-vehicle camera of the present invention, and FIG. 2 is a flowchart of the control operation of the in-vehicle camera.

  As shown in FIG. 1, the in-vehicle camera 10 includes a lens optical system 1, an iris 2 that adjusts the amount of incident light, an image sensor 3 that photoelectrically converts light from the lens optical system 1 into an image signal, and an iris. The exposure control unit 4 controls the amount of light 2 and controls the amount of light accumulated on the light receiving surface of the image pickup device 3, performs predetermined signal processing on the image pickup signal and outputs an image signal, and receives light from the image pickup device 3. A signal processing unit 5 that outputs light amount data corresponding to the amount of light emitted to the surface, a white balance control unit 6 that performs white balance correction control on the image data, and at least one switch 9 (in FIG. 1 is described for convenience), a detection unit 7 that is connected to the switch 9 and detects the ON or OFF of the switch 9 and outputs a detection signal, and setting of exposure and white balance, which will be described later. A storage unit 11 for storing to, and a control unit 8. The control unit 8 is connected to the detection unit 7 and the signal processing unit 5, reads out exposure control setting data from the storage unit 11 based on the light amount data output from the signal processing unit 5, and also controls the exposure control unit 4. In response to detection by the detection unit 7, the correction data is read from the storage unit 11 and the correction data is output to the white balance control unit 6.

  Note that the switch 9 may detect the type of the specific light source (the type indicates a vehicle headlight, fog lamp, blinker, high beam, or over beam, etc.). Since the type of the light source can be detected in this way, when the specific light source is exchanged, the exposure control of the in-vehicle camera 10 can be performed even if the light characteristic of the specific light source exchanged with the specific light source used is changed. The setting and white balance correction control setting can be switched by the control unit 8 without changing by the user.

  As a method of detecting the type of specific light source, a connector having an arbitrary shape is provided for the specific light source, a connector having a shape connectable to a plurality of specific light source connectors is provided on the vehicle side, and the connector on the vehicle side and the connector on the specific light source side are provided. There is a method of detecting the shape of the connector on the specific light source side using a connector shape detecting means provided on the connector on the vehicle side and specifying the type of the specific light source.

  Also, instead of the method of specifying the type of the specific light source with the shape of the connector of the specific light source, the specific light source is detected by detecting the amount of change in voltage when the connector on the specific light source side and the connector on the vehicle side are connected. It may be detected.

  Here, data stored in the storage unit 11 will be described.

  The storage unit 11 includes threshold data that can be set by the user and correction data (corresponding to the switch 9) so that the control unit 8 can determine whether the environment in which the in-vehicle camera captures is daytime or nighttime by comparing the light amount data. When there are a plurality of switches, correction data corresponding to each switch is stored.

  The correction data is obtained by installing a specific light source on a vehicle, lighting the vehicle, photographing with the in-vehicle camera 10 and comparing the object to be photographed with the photographed image displayed on the display device. Data such as color temperature and brightness are calculated and calculated based on the calculated data.

  Therefore, by storing the correction data in the storage unit 11, only the switch 9 is turned on, and the white balance corresponding to the specific light source connected to the switch 9 can be obtained by the control unit 8 without performing complicated calculations. Since correction control can be performed and correction data calculation work is not required, it is possible to display clearly without taking time from shooting of a shooting target to display of a shot image on a display device.

  The above threshold value data can be set. The setting method is to display a certain setting screen on the display device, and set by a known method or the like using the touch panel or operation buttons provided on the switch 9 or the display device. To do.

  Here, the output of the switch 9 and correction data will be described.

  For example, if the three switches 9 have a headlight, a direction indicator lamp, and a stop lamp, and correction data is stored in the storage unit 11 for each of them, only the headlight switch 9 is turned ON and the other If the switch is turned OFF, the control unit 8 reads correction data corresponding to the headlamp from the storage unit 11 and outputs the correction data to the white balance control unit 6, and white balance correction control is performed by the whiy balance control unit 6. .

  Next, assuming that the switches 9 for the headlight, the direction indicator, and the stop lamp are turned on, the control unit 10 reads the headlight correction data from the storage unit 11 with priority given to the headlight with a higher light amount. The white balance control unit 6 outputs the white balance and the white balance control unit 6 performs white balance correction control.

  Alternatively, instead of giving higher priority to the headlight with a higher light amount, the control unit 10 reads the correction data of the headlight, the direction indicator, and the stop lamp from the storage unit 11, and outputs them to the white balance control unit 6, White balance correction control is performed by the white balance control unit 6.

  In addition, instead of reading the correction data of the headlight, the direction indicator, and the stop lamp from the storage unit 11, a combination pattern in which the switch 9 is turned on (headlight and stop lamp, direction indicator and stop lamp) , Headlight and direction indicator, combination pattern of headlight and direction indicator and stop lamp) are stored in the storage unit 11, and the control unit 10 reads the correction data for each pattern and performs white balance control. The white balance correction control is performed by the whi balance control unit 6.

  Next, the operation of the in-vehicle camera 10 will be described in detail with reference to FIG.

  First, the control unit 8 provided in the in-vehicle camera 10 determines whether the switch 9 is ON or OFF based on a detection signal input from the detection unit 7 (step 1).

  If the switch 9 is ON, the control unit 8 determines that the shooting range of the in-vehicle camera 10 is illuminated by the light from the specific light source. If the switch 9 is OFF, the control unit 8 is detected by natural light such as sunlight. It is determined that the shooting range of the in-vehicle camera 10 is being irradiated.

  When the control unit 8 detects that the switch 9 is OFF, the control unit 8 outputs normal exposure control setting data, which will be described later, to the exposure control unit 4, and normal white balance correction setting data, which will be described later, to the white balance control unit 6. The exposure control unit 4 performs exposure control corresponding to the normal exposure control setting data, and the white balance control unit 6 performs white balance control corresponding to the white balance correction setting (step 4).

  Returning to Step 1, when the switch 9 is detected as ON by the control unit 8, the control unit 8 determines whether the light incident on the image sensor 3 is natural light such as sunlight or light of a specific light source. Therefore, the light receiving surface of the image pickup device 3 is divided into a plurality of areas, and the light quantity of an arbitrary area is detected based on the light quantity data of the signal processing unit 5, and the light quantity of an area adjacent to the arbitrary area is compared. The light quantity difference is detected, and natural light or light from a specific light source is determined according to the magnitude of the light quantity difference between the areas (step 2).

  When the control unit 8 determines that the light amount difference between the areas is smaller than a predetermined value (threshold value data) in step 2 and natural light such as sunlight, the control unit 8 controls normal exposure control setting data, which will be described later, for exposure control. And outputs normal white balance correction setting data, which will be described later, to the white balance control unit 6 (step 3). The exposure control unit 4 performs exposure control in accordance with the normal exposure control setting data, and performs white balance. The controller 6 performs white balance control corresponding to the white balance correction setting data (step 4).

  The reason for determining the natural light such as sunlight as the difference in light amount is smaller than the predetermined value is that the natural light such as sunlight and the light for the specific light source are compared in terms of the light amount and the light irradiation range. Natural light has a larger amount of light than the light of a specific light source, and the light irradiation range is larger for natural light such as sunlight than that of a specific light source, so if the light of a specific light source is extinguished by natural light such as sunlight It is possible.

  That is, when natural light such as sunlight is received, light enters the entire light receiving surface of the image sensor 3 to reduce the light amount difference, and the control unit 8 determines that the light amount difference is small and natural light such as sunlight. As described above, the exposure control unit 4 performs exposure control corresponding to the normal exposure control setting data, and the white balance control unit 6 performs white balance control corresponding to the white balance correction setting data.

  Thereby, a clear photographed image can be displayed on a display device (not shown).

  Returning to Step 2, when the control unit 8 determines that the light amount difference between the regions is equal to or greater than a predetermined value (threshold value data) as light of the specific light source, the control unit 8 is based on the detection signal of the detection unit 7. The specific light source is specified, and the color correction setting data (correction data) for specific light source is read from the storage unit 11 corresponding to the detection signal (switch 9), and the exposure control setting data for specific light source, which will be described later, is read into the exposure control unit 4. The specific light source color correction setting data (correction data) is output to the white balance control unit 6 (step 5), and the exposure control unit 4 performs exposure control in accordance with the specific light source exposure control setting data to obtain white. The balance control unit 6 performs white balance correction control corresponding to the specific light source color correction setting data (correction data) (step 4).

  The reason for determining the specific light source as having a large light amount difference is that the specific light source has a larger light amount than natural light such as sunlight as described above, and the light irradiation range is also larger than the light of the specific light source. Light is thought to be drowned out by natural light such as sunlight, but when there is no natural light such as sunlight, the light irradiation range of a specific light source is smaller than that of natural light such as sunlight. This is because the range that is spot-irradiated is limited, and the range where light is irradiated and the range where light is not irradiated become clear.

  That is, when shooting is performed by irradiating the imaging object with a specific light source, a region with a large amount of light and a region with a small amount of light are formed among a plurality of regions obtained by dividing the light receiving surface of the imaging element 3. The light amount difference becomes large, and the control unit 8 determines that the light of the specific light source is irradiated on the object to be photographed because the light amount difference between the regions is large. As described above, the exposure control unit 4 sets the exposure control setting for the specific light source. Exposure control is performed corresponding to the data, and the white balance control unit 6 performs white balance correction control corresponding to the specific light source color correction setting data (correction data).

  Thereby, a clear photographed image can be displayed on a display device (not shown).

  As described above, by performing exposure control and white balance correction control according to natural light such as sunlight or light for a specific light source, an optimally captured image can be displayed on a display device (not shown).

  In addition, about the reference | standard of the light quantity difference of the said step 2, since there is a difference in irradiation of natural light, such as sunlight, according to a downtown area or a suburb area, the setting of the threshold value data preserve | saved at the control part 8 is changed. Thus, it is possible to change the reference of the light amount difference between regions, and to perform appropriate exposure control and white balance control according to the region and environment.

  Here, the exposure setting for exposure control when the switch 9 is OFF and the magnitude of the light amount difference between the plurality of regions on the light receiving surface of the image sensor 3 is large, which is not explained in the control flow, The white balance correction setting of the white balance correction control will be described.

  When the switch 9 is OFF and the light amount difference between the areas is equal to or greater than a predetermined value (threshold data), the exposure control unit 4 performs exposure control based on the normal exposure control setting, and the white balance control unit In step 6, normal white balance correction control is performed.

  When the switch 9 is OFF, the specific light source does not irradiate light, so there is no need to perform exposure control and color correction control for the specific light source (corresponding to step 5 in the above flow) (external to street lights, etc.) The specific light source according to the environment is not limited to this and will be described later).

  The reason why the difference in the amount of light is large is that, for example, when another vehicle traveling in front of the vehicle being driven is taken as an object to be photographed and the other vehicle is irradiated with natural light such as sunlight. Natural light such as sunlight may be blocked by buildings and trees.

  Therefore, the fact that natural light such as sunlight is blocked by buildings, trees, etc. and the difference in the amount of light exceeds a predetermined value is a moment during traveling and is not so large as to affect photographing. Exposure control is performed based on the exposure control setting, and the white balance control unit 6 may perform white balance correction control based on the normal white balance correction control setting.

  Next, the exposure control setting of the present application will be described in detail.

  The exposure control in the normal exposure control setting data is to perform exposure control based on the light amount of the light receiving surface of the image sensor 3 described above.

  In this way, exposure control is performed based on the amount of light on the light receiving surface when natural light such as sunlight is not irradiated or light from a specific light source is used, so that exposure control is performed over a wide range of the entire region, so that the shooting range is full. Can be optimally displayed on a display device or the like.

  Further, the exposure control in the specific light source exposure setting is based on the average received light amount of a region having a light amount greater than or equal to a predetermined value among the divided regions by dividing the light receiving surface of the image sensor 3 described above into a plurality of regions. Exposure control.

  And preferably, in order to clarify the boundary between the divided areas, the lower limit value (threshold value data) of the light quantity area is set, and the area having the light quantity above the lower limit value is set. Make exposure control possible.

  This is because when the light amount difference between the region with the smallest amount of light and the region with the smallest amount of light is greater than or equal to a predetermined value, the light amount difference between adjacent regions is relatively small compared to the predetermined value. Since the range becomes difficult to understand, a lower limit value of the light amount is set in order to clarify the irradiation range. This lower limit value can be set by the user as described above.

  In this way, by performing exposure control based on the amount of light in a region with a large amount of light, for example, an arbitrary photographing object can be photographed, and a photographed image of the photographing object can be clearly displayed on the display device.

  Since the irradiation range of the specific light source is generally based on the premise that the object to be imaged is irradiated, the object to be imaged can be clearly imaged by performing exposure control corresponding to the light of the specific light source.

  Next, the color correction setting of the present application will be described in detail.

  Regarding the white balance correction control in the normal white balance correction setting data, the white balance correction control is performed so that the white part of the imaging target is displayed white.

  In this way, when the natural light such as sunlight or the light of the specific light source is not irradiated, the white balance correction control is performed on the area of the light receiving surface of the image sensor 3, so that the display device can be clearly displayed over a wide range of the entire area. Can be displayed.

  The color correction setting data for specific light source (correction data) differs depending on the type of switch that turns on the direction indicator or the back lamp, but the color of the light depends on the type of switch. The weight is changed.

  The white balance is normally displayed on the display device so that the white color looks white by controlling the red and blue colors with reference to the green wavelength. When white balance correction control is performed using the white balance correction setting data, the subject displayed on the display device is not displayed on the display device by the white balance correction control, but is changed to a bluish red.

  For example, in the case where the specific light source is a red brake lamp, the driver depresses the brake pedal or the like, so that the brake lamp (switch 9) is turned on and the rear side of the vehicle is photographed to photograph the object to be photographed. When displayed on the display device, in the white balance correction control using the normal white balance correction setting data, the shooting object displayed on the display device is bluish red even though the shooting object is illuminated by a red lamp. Is displayed.

  This is because white balance correction control is performed so that the weights of red and blue colors are uniform with respect to green, and thus the object to be photographed displayed on the display device is displayed in bluish red.

  Therefore, the white balance control unit 6 performs control for reducing the blue weight by the white balance correction control using the color correction setting data (correction data) for the specific light source and causing the display device to display a reddish color similar to the object to be photographed. This makes it possible to reduce the difference in color temperature between the object to be imaged and the captured image.

  Therefore, according to the color of the light of the specific light source, the difference in color temperature can be reduced between the imaging object actually captured and the captured image captured and displayed on the display device.

  Here, the adaptation of the exposure setting and the white balance setting according to the shooting situation will be described specifically with reference to FIG. 3 while corresponding to the flow of FIG.

  FIG. 3A shows an image taken by an in-vehicle camera, in which a photographed image is displayed on a display device, and is a photographed image in which natural light such as sunlight is uniformly radiated to an arbitrary object A and its surroundings. .

  Although the photographed image is divided into 16 areas, it is equivalent to dividing the light receiving surface of the image sensor 3 into 16 areas.

  Further, the description will be made assuming that the image displayed on the display device and the range of the light receiving surface of the image sensor 3 are the same for convenience.

  The flow when natural light such as sunlight is uniformly applied to an arbitrary object A and its surroundings is determined by the control unit 8 in step 1 by determining whether the switch 9 is turned on or off. After determining that the switch is ON, it is determined in step 2 that the light amount difference between the areas is smaller than a predetermined value (threshold value data). In step 3, the normal exposure control setting data and the normal white balance setting are set to the control unit 8. Is output to the exposure control unit 4 and the white balance control unit 6, and the exposure control and white balance control are performed in step 4 in accordance with the normal exposure control setting data and the normal white balance setting.

  In this example, exposure control and white balance control are performed with the 16 divided areas as one area.

  Therefore, when an arbitrary object A is to be photographed, the entire photographing range including the arbitrary object A and its peripheral part is controlled to be exposed, so that the arbitrary object A and its peripheral part are optimally controlled. Thus, the captured image of the entire imaging range can be clearly displayed on the display device.

  FIG. 3B is a photographed image obtained by irradiating an arbitrary object A with light of a specific light source, in which a photographed image is displayed on a display device by photographing with a vehicle-mounted camera.

  The captured image is divided into 16 areas, which is equivalent to dividing the light receiving surface of the image sensor 3 into 16 areas.

  Further, the description will be made assuming that the image displayed on the display device and the range of the light receiving surface of the image sensor 3 are the same for convenience.

  When light of a specific light source is irradiated to an arbitrary object A, the control unit 8 determines that the switch 9 is turned on in Step 1 and the light amount difference between regions is a predetermined value (threshold data) or more in Step 2 In step 5, the specific light source exposure control setting data and the specific light source color correction setting data are output from the control unit 8 to the exposure control unit 4 and the white balance control unit 6. In step 4, the normal exposure control setting is performed. This is a flow in which exposure control and white balance correction control are performed in accordance with data and color correction setting data for a specific light source.

  In the white balance correction control, the control unit 8 reads the correction data from the storage unit 11 based on the detection signal of the detection unit 7 and outputs the correction data to the white balance control unit 6, and the white balance correction control is performed based on the correction data. I do.

  Specifically, in this example, the control unit 8 compares the light amount difference between adjacent regions of the 16 divided regions, and limits the range to four regions where the light amount difference is large and the light amount is large. The exposure control is performed by averaging the amount of light in the selected range, and the white balance control is performed corresponding to the specific light source (the type of the switch that is turned on).

  Therefore, by performing exposure control only for the range of the region with a large amount of light, an arbitrary object A irradiated with light can be optimally photographed and can be clearly displayed on a display device (not shown).

  Further, when the exposure range of the entire shooting range is controlled, the exposure is reduced as a whole shooting range due to the difference in the amount of light between the light irradiating portion and its peripheral portion, thereby preventing a dark shooting image of an arbitrary object A. Can do.

  FIG. 3C is a photograph of an in-vehicle camera, where a photographed image is displayed on a display device, and is a photographed image that is not irradiated with light and is entirely dark.

  The photographed image is divided into 16 areas, which is equivalent to dividing the light receiving surface of the image sensor 3 into 16 areas.

  Further, the description will be made assuming that the image displayed on the display device and the range of the light receiving surface of the image sensor 3 are the same for convenience.

  In the flow when light is not irradiated and the entire screen is dark, the control unit 8 determines that the switch 9 is turned off in step 1, and the normal exposure control setting data and the normal white balance setting are exposed from the control unit 8 in step 3. This is a flow for outputting to the control unit 4 and the white balance control unit 6 and performing exposure control and white balance control corresponding to the normal exposure control setting data and the normal white balance setting in step 4.

  In this example, exposure control and white balance control are performed with the 16 divided areas as one area.

  Therefore, when an arbitrary object A is to be photographed, exposure control is performed over the entire photographing range, so exposure control and white balance control are performed so as to improve the light quantity of the arbitrary object A and its peripheral part. Object A is photographed optimally.

  Thereby, an arbitrary object A can be clearly displayed on a display device (not shown) even in a dark place.

  FIG. 3D shows an image taken by the in-vehicle camera, in which a photographed image is displayed on a display device, and is a photographed image in which a streetlight is detected as light of a specific light source and a white line on a road is taken as an object to be photographed.

  The flow is similar to the flow in the description of FIG. 3B, but differs in that the light receiving surface of the image sensor 3 is divided into 64 parts.

  Moreover, although the area | region which injected the light of the streetlight of the divided | segmented picked-up image has a high light quantity, others have a low light quantity, the control part 8 is a fixed space | interval on a divided screen, and a specific range. It is determined that a light having a high amount of light has been detected, and it is determined that it is a streetlight.

  Therefore, the control unit 8 determines that the white light that is the object to be photographed is illuminated by street light, outputs the exposure control setting data for the specific light source to the exposure control unit 4, and the exposure control unit 4 performs the exposure control. Is called.

  Therefore, the white line becomes clear and the image can be photographed optimally.

  Thus, in the in-vehicle camera of the present invention, the photographed image is displayed by the conventional daytime and nighttime, the exposure control and the white balance correction control are not performed according to the environment outside the vehicle such as an urban area or a suburb. However, when the subject is shot, the exposure range can be set by judging the natural light such as sunlight or the light of a specific light source. Balance correction control is performed, and the object to be photographed can be photographed satisfactorily.

  In particular, because the exposure range and color compensation are set according to the type of light source, the exposure is too strong and brightly displayed on the display device according to the type of light source as before, or the color of the object being shot And the like such as a difference in the color of the captured image displayed on the display device can be solved.

  Further, since correction data is stored in advance in the storage unit and white balance correction control corresponding to the specific light source is performed by turning on the specific light source, the correction data is stored in the control unit corresponding to the specific light source. Without calculation, it is possible to perform from shooting to display of a shot image in a short time.

  Here, the operation timing of the camera when the vehicle-mounted camera is mounted on a car will be described.

  The in-vehicle camera does not necessarily need to be operated at the same time as turning on the vehicle. By performing a photographing operation when necessary, it is possible to prevent the in-vehicle camera from being deteriorated and to reduce wasteful power.

  For example, the in-vehicle camera may be operated according to how the car gears are engaged.

  Specifically, when the user sets the gear to drive the vehicle forward, the vehicle-mounted camera arranged in front is operated so as to photograph the front of the vehicle, or a rotation that allows photographing in all directions is performed. It is good also as a structure which mounts a dynamic vehicle-mounted camera in a vehicle, and rotates the front and image | photographs.

  Similarly, when the vehicle is driven backward, the vehicle-mounted camera disposed at the rear may be operated or the vehicle-mounted camera may be rotated to capture the rear of the vehicle.

  It should be noted that the present invention is not limited to the above embodiment, and various improvements may be made as long as they do not depart from the gist of the present invention.

  For example, an external light detection unit or a timer that detects light outside the vehicle may be provided to determine daytime or nighttime.

  According to this configuration, when the control unit 8 determines that the switch 9 is ON and the difference in the amount of light between the areas is small in step 2 and when it is determined by the outside light detection unit or the timer that it is nighttime, it is specified. When the light of the light source is not irradiated due to the failure of the specific light source, a warning such as replacement of the specific light source may be warned by a display device in the vehicle, a warning sound by a speaker or the like, or a vibration of the handle.

  Further, in the above embodiment, the light amount is output by the signal processing unit 5 based on the image pickup signal from the image pickup device 3. However, the present invention is not limited to this, and a separate light detection means is provided to detect the light amount. Also good.

  Furthermore, the specific light source exposure control setting data is output by the control unit 8 according to the amount of light incident on the light receiving surface of the image sensor 3, but the specific light source exposure control setting is detected by detecting whether the switch 9 is ON or OFF. Data may be output.

  That is, the light source connected to the switch 9 is specified in advance, and the color temperature of the light source and the light irradiation range can also be specified.

  Therefore, if the exposure setting corresponding to the specified color temperature of the light source or the light irradiation range is stored in the storage unit 11, the control unit 8 detects ON or OFF of the switch 9 and exposes to the exposure control unit 4. Settings can be output, and high-precision exposure control can be performed.

It is an area | region figure of the vehicle-mounted camera of this invention. It is a flowchart of control operation of a vehicle-mounted camera. It is explanatory drawing which displayed the picked-up image on the display apparatus by image | photographing with a vehicle-mounted camera, (a) is a picked-up image by which natural light, such as sunlight, was uniformly irradiated to the arbitrary object A and its periphery. (B) is a photographed image obtained by irradiating an arbitrary object A with light from a regular light source. (C) is a photographed image that is not irradiated with light and is entirely dark. (D) is a photographic image in which a streetlight is detected as light of a specific light source and a white line on the road is taken as an photographic object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lens optical system 2 ... Iris 3 ... Imaging device 4 ... Exposure control part 5 ... Signal processing part 6 ... White balance control part 7 ... Detection part 8 ... Control unit 9 ... switch 10 ... vehicle-mounted camera 11 ... storage unit

Claims (9)

Detecting means for detecting lighting of the light source of the vehicle;
Imaging means for photoelectrically converting incident light into an imaging signal;
White balance control means for adjusting white balance of the imaging signal;
And a storage unit that stores correction data corresponding to the light source. When the detection unit detects lighting of a light source of a vehicle, white balance adjustment is performed using the correction data. The storage means stores a plurality of correction data,
A selection means for selecting arbitrary correction data from the plurality of correction data;
3. The in-vehicle camera according to claim 2, wherein when the light source of the vehicle is detected by the detection unit, white balance adjustment is performed using the correction data selected by the selection unit. The detection means detects lighting of a plurality of light sources of a vehicle,
The storage means stores correction data corresponding to each of the plurality of light sources,
The white balance adjustment is performed using the correction data corresponding to the light source from which lighting is detected when lighting of any of the plurality of light sources of the vehicle is detected by the detecting means. The in-vehicle camera described in 1. A light amount detecting means for detecting the amount of received light for each of a plurality of areas on the light receiving surface of the imaging means, and a means for detecting the presence of an area having a light receiving amount of a predetermined value or more in the plurality of areas,
When the lighting of the light source of the vehicle is detected by the detecting means and when it is detected that there is a region having a light receiving amount of a predetermined value or more, white balance adjustment is performed using the correction data. The in-vehicle camera according to any one of claims 1 to 3. Exposure control means for controlling the amount of incident light of the imaging means,
Based on the average received light amount of the region having the received light amount equal to or greater than the predetermined value when the detection unit detects the lighting of the light source of the vehicle and detects that the region having the received light amount equal to or greater than the predetermined value exists. The in-vehicle camera according to claim 4, wherein the amount of incident light is controlled by the exposure control means. The light amount detecting means for detecting the received light amount for each of a plurality of areas on the light receiving surface of the imaging means, and detecting the presence or absence of an area having a light quantity difference of a predetermined value or more in comparison with other adjacent areas in the plurality of areas. And further comprising means
When the lighting means of the vehicle light source is detected by the detecting means and when it is detected that there is a region having a light amount difference of a predetermined value or more, white balance adjustment is performed using the correction data. The in-vehicle camera according to any one of claims 1 to 3. Exposure control means for controlling the amount of incident light of the imaging means,
When detecting the lighting of the light source of the vehicle by the detecting means and detecting that there is a region having a light amount difference of a predetermined value or more, based on the average received light amount of the region having the light amount difference of the predetermined value or more. The in-vehicle camera according to claim 6, wherein the exposure control is performed. A light amount detecting means for detecting a received light amount for each of a plurality of areas on the light receiving surface of the imaging means; a means for detecting the presence of a light receiving quantity of a predetermined value or more in the plurality of areas; and A means for detecting the presence or absence of a region having a light amount difference of a predetermined value or more compared with other adjacent regions, and an exposure control unit for controlling the incident light amount of the imaging unit;
Based on the average received light amount of the region having the received light amount equal to or greater than the predetermined value when the detection unit detects lighting of the light source of the vehicle and detects that there is a region having a light amount difference greater than or equal to the predetermined value. The in-vehicle camera according to claim 1, wherein the exposure control is performed. A light amount detecting means for detecting the amount of received light for each of a plurality of areas on the light receiving surface of the imaging means, a means for detecting the presence of a region having a light receiving amount equal to or less than a predetermined value in the plurality of areas, and incidence of the imaging means Exposure control means for controlling the amount of light,
When detecting the lighting of the light source of the vehicle by the detecting means and detecting that there is a region having a light reception amount equal to or less than a predetermined value, the average light reception of regions other than the region having the light reception amount equal to or less than the predetermined value The in-vehicle camera according to claim 1, wherein the exposure control is performed based on a quantity.

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