JP4194860B2 - Imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image pickup apparatus that switches between color shooting and black-and-white shooting, and more particularly to a technique for improving the switching accuracy.
[0002]
[Prior art]
Conventionally, a color / monochrome switching camera is known as an image pickup apparatus having a color / monochrome switching function (see, for example, Patent Document 1). This color / monochrome switching camera includes a charge storage element (hereinafter referred to as “CCD”) having sensitivity to light from the visible region to the infrared region, a lens for imaging incident light from a subject on the CCD, An infrared cut filter (hereinafter referred to as “IR cut filter”) that removes light in the infrared region (infrared component) from incident light, and allows the incident light to pass through as it is and the optical path length is equal to the IR cut filter. A signal for generating a color signal (composite video signal) Cout and a black and white signal (luminance signal) Yout from the dummy glass, the slide mechanism for switching the IR cut filter and the dummy glass between the lens and the CCD, and the output signal of the CCD A processing circuit, a detection circuit for integrating Yout to detect the brightness of light incident on the CCD, and an IR cut filter A state sensor for detecting which of the data and the dummy glass is inserted, a changeover switch for selecting one of the color signal Cout and the monochrome signal Yout as an output video signal, a signal from the detection circuit and the state sensor A microcomputer (hereinafter referred to as “microcomputer”) for controlling the motor for driving the slide mechanism and controlling the changeover switch is provided.
[0003]
The light from the subject is imaged on the CCD by the lens, but passes through the IR cut filter or the dummy glass at that time. Since the optical path length of the IR cut filter is equal to the optical path length of the dummy glass, the image point does not shift even when the filter is switched. Further, the IR cut filter and the dummy glass are supported by a slide mechanism, and either one can be freely inserted between the lens and the CCD by a motor.
[0004]
Since the CCD is also sensitive to light in the infrared region, there is a problem that if the light from the subject is imaged on the CCD during color photographing, the reproduced color is reddish. Therefore, the light from which the infrared component is removed by the IR cut filter is imaged on the CCD to prevent the color from being reddish. However, since the infrared component is removed from the light from the subject, the electric signal obtained from the CCD becomes small in photographing under low illumination, and there is a problem that the sensitivity is lowered. Therefore, in a color / monochrome switching camera, the IR cut filter is switched to a dummy glass under low illuminance to prevent the decrease in sensitivity by allowing light in the infrared region to pass. However, since the color is reddish by passing light in the infrared region, it is necessary to switch the video signal output from the color / monochrome switching camera from the color signal Cout to the monochrome signal Yout (see, for example, Patent Document 1). ).
[0005]
The light imaged on the CCD is converted into an electrical signal, and is converted into a color signal Cout and a monochrome signal Cout by the signal processing circuit 6. The black and white signal Yout is integrated in the detection circuit and sent to the microcomputer. The microcomputer converts the integrated value from the detection circuit into an incident light amount. When the incident light amount is greater than or equal to a predetermined determination value, the microcomputer determines that the color photographing is performed, and when the incident light amount is smaller than the determination value, it determines black and white photographing.
[0006]
If the microcomputer determines that the color shooting is performed, the state sensor checks whether an IR cut filter or a dummy glass is inserted in the optical path from the lens to the CCD. Then, a rotation command is issued to operate the slide mechanism, and switching is performed so that an IR cut filter is inserted in the optical path. At the same time, the selector switch is controlled so that the color signal Cout is output.
[0007]
On the other hand, if the microcomputer determines that black-and-white photography is performed, the state sensor checks whether an IR cut filter or a dummy glass is inserted in the optical path from the lens to the CCD, and if an IR cut filter is inserted. A rotation command is issued to the motor to operate the slide mechanism, so that the dummy glass is inserted into the optical path. At the same time, the selector switch is controlled so that the monochrome signal Yout is output.
[0008]
Through the above operation, color shooting with light passing through the IR cut filter under high illuminance and black-and-white shooting with light passing through the dummy glass under low illuminance can be realized, preventing a decrease in sensitivity under low illuminance. be able to.
[0009]
Thus, in the conventional color / monochrome switching camera, switching between color photography and monochrome photography is performed by the microcomputer determining the amount of incident light. However, when the transition from color shooting to black-and-white shooting is performed, the amount of incident light increases by the amount of the infrared component, so it is determined that the amount of incident light is small in color shooting despite the fact that the luminance of the subject does not change. There may be a situation where it is determined that the amount of incident light is large. As a result, there is a possibility of causing a hunting phenomenon in which the state between color photography and monochrome photography continues to change.
[0010]
In order to solve such a problem, conventionally, the determination value of the incident light amount at the time of determining as color shooting is increased, and the determination value of the incident light amount at the time of determination of black and white shooting is decreased, so Hysteresis is formed in the judgment value of the incident light quantity with photographing to prevent the occurrence of the hunting phenomenon. Further, it is possible to prevent occurrence of a hunting phenomenon by determining whether the color shooting or the black-and-white shooting is performed so that the incident light amount greater than the determination value or the incident light amount smaller than the determination value does not continue for a certain period of time. It is preventing.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-239356 (page 7-8, FIG. 1)
[0012]
[Problems to be solved by the invention]
As described above, conventionally, the occurrence of the hunting phenomenon is prevented by forming a hysteresis in the determination value of the incident light quantity between color photography and monochrome photography, but the difference in incident light quantity between color photography and monochrome photography is It varies depending on the ratio between the infrared component and the visible component of light. For example, when a halogen lamp is used for illumination, the sensitivity difference between color photography and monochrome photography is about 15 times. Accordingly, it is necessary to take a considerably large amount of hysteresis in order to prevent the occurrence of the hunting phenomenon. As a result, it is necessary to increase the judgment value of the incident light quantity when returning from black and white photography to color photography, and if the light source does not contain a lot of infrared components, it is difficult to return from black and white photography to color photography even if it becomes brighter. There's a problem.
[0013]
In addition, conventionally, it is configured so that whether it is color photography or black-and-white photography is determined so that an incident light amount that is greater than or equal to a determination value or an incident light amount that is less than a determination value does not continue for a certain amount of time or longer. For example, when road monitoring is performed with a color / monochrome switch camera, when the car is running toward the camera in black and white photography, if the headlight is a halogen lamp, near red Since many external components are included, there is a problem that the headlight and the image portion of the area irradiated with the headlight cause halation. In the case of such a subject, it is possible to prevent halation by cutting the near-infrared component in the color shooting state, but since the car will leave the camera's field of view within a few seconds, it is necessary to manually perform color shooting. It is difficult to switch quickly.
[0014]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an imaging apparatus capable of switching between color photography and monochrome photography with high accuracy and speed.
[0015]
[Means for Solving the Problems]
  An image pickup apparatus according to the present invention includes an IR cut filter that is inserted in an optical path from a lens to a photosensitive element and removes an infrared component from incident light, and a dummy glass that is inserted in the optical path and allows incident light to pass through as it is. A date information acquisition unit that acquires date information representing the current date, a time information acquisition unit that acquires time information representing the current time, a sunrise time based on the date information acquired by the date information acquisition unit, and A calculation unit for calculating the sunset time;
The weather information acquisition unit that acquires the weather information representing the current weather, and the sunrise time and sunset time calculated by the calculation unit according to the current weather represented by the weather information acquired by the weather information acquisition unit The current time represented by the fine correction unit to be corrected and the time information acquired by the time information acquisition unit is corrected by the fine correction unit.A control unit is provided that inserts an IR cut filter into the optical path to perform color photographing from the sunrise time to sunset time, and inserts a dummy glass to perform black and white photographing otherwise.
[0016]
  An image pickup apparatus according to the present invention includes an IR cut filter that is inserted in an optical path from a lens to a photosensitive element and removes an infrared component from incident light, and a dummy glass that is inserted in the optical path and allows incident light to pass through as it is. And a detection unit that detects whether or not halation is occurring based on a signal from the photosensitive element, and that the detection unit has caused halation in a state where a dummy glass is inserted into the optical path and monochrome photography is performed. A control unit that, when detected, inserts an IR cut filter into the optical path to perform color photography,
The detection unit has a high luminance detection circuit that detects a high luminance part based on a signal from the photosensitive element, and halation occurs when the high luminance part detected by the high luminance detection circuit has a predetermined shape. And an image comparison unit for detecting the effect.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
The imaging apparatus according to Embodiment 1 of the present invention switches between color photography and monochrome photography based on date information, time information, and weather information.
[0018]
FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to Embodiment 1 of the present invention. This imaging device includes a lens 1, an IR cut filter 2, a dummy glass 3, a slide mechanism 4, a CCD 5, a signal processing circuit 6, a date information acquisition unit 7, a time information acquisition unit 8, a weather information acquisition unit 9, a state sensor 10, It consists of a microcomputer 11, a motor 12, and a changeover switch 13.
[0019]
The lens 1 collects light from the subject and passes the IR cut filter 2 or the dummy glass 3 to form an image of the subject on the CCD 5. The IR cut filter 2 removes the infrared component from the light collected by the lens 1 and passes it. The dummy glass 3 allows the light collected by the lens 1 to pass through as it is.
[0020]
The slide mechanism 4 supports the IR cut filter 2 and the dummy glass 3 and is driven by the motor 12 to insert either the IR cut filter 2 or the dummy glass 3 into the optical path from the lens 1 to the CCD 5. When the IR cut filter 2 is inserted into the optical path by the slide mechanism 4, light that does not include the infrared region is guided to the photosensitive portion (not shown) of the CCD 5, and the dummy glass 3 is inserted into the optical path. The light including the infrared region is guided to the photosensitive portion of the CCD 5.
[0021]
The CCD 5 converts the light imaged on the photosensitive portion into an electrical signal. The CCD 5 has sensitivity also in the infrared region. Accordingly, the CCD 5 outputs an electrical signal that is larger when light that has passed through the dummy glass 3 is input than when light that has passed through the IR cut filter 2 is input. The electric signal output from the CCD 5 is sent to the signal processing circuit 6.
[0022]
The signal processing circuit 6 converts the electrical signal sent from the CCD 5 into a luminance signal Yout (monochrome signal) and an NTSC composite signal Cout (color signal) and sends them to the changeover switch 13 respectively. Further, the signal processing circuit 6 sends a vertical synchronization signal VD to the microcomputer 11 to start the operation of the microcomputer 11.
[0023]
The changeover switch 13 selects either the luminance signal Yout from the signal processing circuit 6 or the NTSC composite signal Cout in accordance with the video switching signal from the microcomputer 11 and outputs it as a video signal to the outside.
[0024]
The date information acquisition unit 7 can be composed of, for example, a GPS receiver, a radio clock, an Internet clock, a calendar mechanism built in the microcomputer 11, and the like. The GPS receiver generates date information representing the current date based on information sent from a GPS satellite. The radio timepiece receives standard radio waves transmitted from a predetermined transmitting station and generates date information representing the current date. The Internet clock receives date information representing the current date from the Internet. The date information acquired by the date information acquisition unit 7 is sent to the microcomputer 11.
[0025]
The time information acquisition unit 8 can be constituted by, for example, a GPS receiver, a radio clock, an Internet clock, a clock mechanism built in the microcomputer 11, and the like. The GPS receiver generates time information representing the current time based on information sent from a GPS satellite. The radio timepiece receives a standard radio wave transmitted from a predetermined transmitting station and generates time information indicating the current time. The Internet clock receives time information representing the current time from the Internet. The time information acquired by the time information acquisition unit 8 is sent to the microcomputer 11.
[0026]
The weather information acquisition unit 9 can be configured by software that receives weather information from the Internet, for example. The weather information acquired by the weather information acquisition unit 9 is sent to the microcomputer 11.
[0027]
The state sensor 10 detects which of the IR cut filter 2 and the dummy glass 3 is inserted in the optical path from the lens 1 to the CCD 5. The result detected by the state sensor 10 is sent to the microcomputer 11 as a state signal.
[0028]
The motor 12 drives the slide mechanism 4 according to a control signal from the microcomputer 11. As a result, either the IR cut filter 2 or the dummy glass 3 is inserted into the optical path from the lens 1 to the CCD 5.
[0029]
The microcomputer 11 performs color imaging based on the date information from the date information acquisition unit 7, the time information from the time information acquisition unit 8, the weather information from the weather information acquisition unit 9, and the status signal from the state sensor 10 or monochrome. Determine whether to perform shooting. Then, based on this determination result, the motor 12 is activated to drive the slide mechanism 4, whereby either the IR cut filter 2 or the dummy glass 3 is inserted in the optical path from the lens 1 to the CCD 5. Further, the microcomputer 11 controls the changeover switch 13 based on the determination result, selects either the luminance signal Yout or the NTSC composite signal Cout sent from the signal processing circuit 6, and outputs it as a video signal to the outside. To do. The operation of the microcomputer 11 will be described in detail later with reference to a flowchart.
[0030]
Next, the operation of the imaging apparatus according to Embodiment 1 of the present invention configured as described above will be described.
[0031]
First, when the lens 1 of the image pickup device is directed to the subject, light from the subject is collected by the lens 1, passes through the IR cut filter 2 or the dummy glass 3, and forms an image on the photosensitive portion of the CCD 5. Which of the IR cut filter 2 and the dummy glass 3 passes is determined by control of the microcomputer 11 described later.
[0032]
The CCD 5 converts the light imaged on the photosensitive portion into an electric signal and sends it to the signal processing circuit 6. The signal processing circuit 6 converts the electrical signal received from the CCD 5 into a luminance signal Yout (monochrome signal) and an NTSC composite signal Cout (color signal) and sends them to the changeover switch 13 respectively.
[0033]
In parallel with the above operation, the microcomputer 11 executes the following processing. The operation of the microcomputer 11 will be described with reference to the flowchart shown in FIG.
[0034]
The microcomputer 11 is activated when the vertical synchronizing signal VD is sent from the signal processing circuit 6 and starts processing (step ST1). Therefore, the microcomputer 11 first acquires a date when processing that is to be periodically started is started (step ST2). That is, the microcomputer 11 acquires date information from the date information acquisition unit 7.
[0035]
Next, the sunset time and sunrise time are calculated (step ST3). Specifically, the microcomputer 11 recognizes the current date based on the date information acquired in step ST2, and calculates the sunrise time and sunset time on the recognized date. The calculation of the sunrise time and the sunset time is performed by referring to a table in which the date, the sunrise time, and the sunset time are stored in advance in the microcomputer 11 in advance. In step ST3, the sunrise time and sunset time can be directly acquired from the Internet. In this case, the process of step ST2 mentioned above becomes unnecessary, and the date information acquisition part 7 becomes unnecessary in connection with it.
[0036]
Next, weather information is acquired (step ST4). That is, the microcomputer 11 acquires weather information from the weather information acquisition unit 9. The weather information acquired here is information representing the current weather in the region where the imaging apparatus is present. And it is investigated whether the weather is bad (step ST5). This is done by checking whether the weather information is clear.
[0037]
If it is determined in step ST5 that the weather is bad, that is, it is not sunny, fine correction of the sunset time and sunrise time is performed (step ST6). This fine correction is performed in order to more accurately determine the brightening time and the darkening time because the surroundings are dark when the weather is bad and the surroundings are dark even after the sunrise time and the surroundings are darkened earlier than the sunset time. In this fine correction process, specifically, a predetermined minute value is subtracted from the sunset time calculated in step ST3 to generate a new sunset time, and a predetermined sunset time is calculated at step ST3. Minor values are added to generate a new sunrise time. The minute value is preferably variable according to the weather information. For example, it is preferable to increase the minute value when the weather information indicates rain rather than when it is cloudy. Thereafter, the process proceeds to step ST7.
[0038]
On the other hand, if it is determined in step ST5 that the weather is not bad, that is, it is clear, the sunset time and sunrise time are not finely corrected, and the process proceeds to step ST7.
[0039]
In the imaging apparatus according to the first embodiment, the sunrise time and sunset time are finely corrected according to the weather at that time, but switching between color photography and monochrome photography is strictly performed. If not necessary, fine correction of the sunrise time and sunset time can be omitted. In this case, the processing of steps ST4 to ST6 is unnecessary, and accordingly, the weather information acquisition unit 9 is also unnecessary.
[0040]
Next, the current time is acquired (step ST7). That is, the microcomputer 11 acquires time information representing the current time from the time information acquisition unit 8. Next, it is checked whether or not the current time represented by the time information is between the sunrise time and the sunset time, that is, the time zone when the sun is rising (step ST8). Here, if it is determined that the current time is not between the sunrise time and the sunset time, it is recognized that the sun is sinking and the surrounding illuminance is insufficient, and steps ST10 to ST11 are performed. Processing for monochrome photography is performed.
[0041]
On the other hand, if it is determined that the current time is between the sunrise time and the sunset time, it is recognized that the sun is rising and the surrounding illuminance is sufficient, and steps ST12 to ST14 are performed. Processing for color photography is performed. Hereinafter, the case of monochrome photography and the case of color photography will be described separately.
[0042]
(A) For black and white photography
In the case of this black-and-white photography, the following processing is executed in order to insert the dummy glass 3 into the optical path from the lens 1 to the CCD 5 and make the video signal output from the imaging device the luminance signal Yout.
[0043]
First, a state signal is input from the state sensor 10 (step ST9). Next, the microcomputer 11 refers to the state signal from the state sensor 10 to check whether the dummy glass 3 is inserted in the optical path from the lens 1 to the CCD 5 (step ST10).
[0044]
Here, when it is determined that the dummy glass 3 is not inserted, that is, the IR cut filter 2 is inserted, switching to the dummy glass 3 and switching to output the luminance signal Yout as a video signal. Is performed (step ST11). Specifically, the microcomputer 11 sends a control signal to the motor 12. As a result, the slide mechanism 4 is driven, and the IR cut filter 2 inserted in the optical path from the lens 1 to the CCD 5 is switched to the dummy glass 3. Further, the microcomputer 11 sends a video switching signal to the changeover switch 13. As a result, the changeover switch 13 is switched from the state of outputting the NTSC composite signal Cout from the signal processing circuit 6 to the state of outputting the luminance signal Yout as the video signal. Thereby, the video signal output from the imaging device becomes the luminance signal Yout.
[0045]
On the other hand, if it is determined in step ST10 that the dummy glass 3 is inserted, the dummy glass 3 has already been inserted in the optical path from the lens 1 to the CCD 5, and the luminance signal Yout is output as a video signal. Thus, the process of step ST11 is skipped. Thus, the process for performing monochrome photography is completed (step ST15).
[0046]
(B) Color shooting
In the case of this color photographing, the following processing is executed in order to insert the IR cut filter 2 in the optical path from the lens 1 to the CCD 5 and to convert the video signal output from the imaging device into the NTSC composite signal Cout.
[0047]
First, a state signal is input from the state sensor 10 (step ST12). Next, the microcomputer 11 refers to the status signal from the status sensor 10 to check whether the IR cut filter 2 is inserted in the optical path from the lens 1 to the CCD 5 (step ST13).
[0048]
Here, when it is determined that the IR cut filter 2 is not inserted, that is, the dummy glass 3 is inserted, switching to the IR cut filter 2 and outputting the NTSC composite signal Cout as the video signal are performed. Switching processing is performed (step ST14). Specifically, the microcomputer 11 sends a control signal to the motor 12. As a result, the slide mechanism 4 is driven, and the dummy glass 3 inserted in the optical path from the lens 1 to the CCD 5 is switched to the IR cut filter 2. Further, the microcomputer 11 sends a video switching signal to the changeover switch 13. As a result, the selector switch 13 is switched from the state of outputting the luminance signal Yout from the signal processing circuit 6 as the video signal to the state of outputting the NTSC composite signal Cout. As a result, the video signal output from the imaging device becomes the NTSC composite signal Cout.
[0049]
On the other hand, if it is determined in step ST13 that the IR cut filter 2 is inserted, the IR cut filter 2 has already been inserted in the optical path from the lens 1 to the CCD 5, and the NTSC composite signal Cout is the video signal. Since it is switched to output, the process of step ST14 is skipped. Thus, the process for performing color photographing is completed (step ST15).
[0050]
As described above, according to the imaging apparatus according to the first embodiment, switching between color photography and monochrome photography is performed based on date information, time information, and weather information. When many external components are not included, the problem that it is difficult to return from monochrome photography to color photography even when the surroundings become bright can be solved.
[0051]
Embodiment 2. FIG.
In the image pickup apparatus according to Embodiment 2 of the present invention, switching from black-and-white photography to color photography is performed by recognizing the shape of the area causing halation.
[0052]
FIG. 3 is a block diagram showing the configuration of the imaging apparatus according to Embodiment 2 of the present invention. The imaging apparatus includes a lens 1, an IR cut filter 2, a dummy glass 3, a slide mechanism 4, a CCD 5, a signal processing circuit 6, a microcomputer 11, a motor 12, a changeover switch 13, a high brightness detection circuit 14, and an image comparison unit 15. Has been.
[0053]
Since the configuration and operation of the lens 1, IR cut filter 2, dummy glass 3, slide mechanism 4, CCD 5, signal processing circuit 6, motor 12 and changeover switch 13 are the same as those of the imaging apparatus according to the first embodiment described above. In the following, description is omitted or simplified.
[0054]
The high luminance detection circuit 14 receives the luminance signal Yout sent from the signal processing circuit 6 and detects a high luminance region in the image formed on the photosensitive portion of the CCD 5. A shape signal representing the shape of the high luminance region detected by the high luminance detection circuit 14 is sent to the image comparison unit 15.
[0055]
The image comparison unit 15 performs shape recognition by comparing the shape of the high luminance region represented by the shape signal sent from the high luminance detection circuit 14 with the shape stored in advance in the image comparison unit 15. If the shape of the region detected by the high luminance detection circuit 14 and the shape stored in the image comparison unit 15 are similar, it is detected that the vehicle has traveled toward the imaging device. The detection result of the image comparison unit 15 is sent to the microcomputer 11.
[0056]
The microcomputer 11 determines whether to perform color imaging or monochrome imaging based on a signal representing the detection result from the image comparison unit 15. Then, based on this determination result, the motor 12 is activated to drive the slide mechanism 4, whereby either the IR cut filter 2 or the dummy glass 3 is inserted in the optical path from the lens 1 to the CCD 5. Further, the microcomputer 11 controls the selection switch 13 based on the determination result, selects either the luminance signal Yout or the NTSC composite signal Cout sent from the signal processing circuit 6, and outputs it as a video signal to the outside. To do.
[0057]
Next, the operation of the imaging apparatus according to Embodiment 2 of the present invention configured as described above will be described. In the following, a case where a car traveling on a road is taken in black and white photography will be described as an example. It is assumed that the image comparison unit 15 stores a shape that appears in common as the shape of the image of the area irradiated with the headlight and the headlight when the car runs toward the imaging device. As shown in FIG. 4, the headlight has two triangles, the area irradiated with the headlight has a vertically long ellipse, and two protrusions are formed on the top of the vertically long ellipse.
[0058]
First, preparation for black and white photography is performed. That is, the microcomputer 11 sends a control signal to the motor 12. As a result, the slide mechanism 4 is driven, and the dummy glass 3 is inserted in the optical path from the lens 1 to the CCD 5. Further, the microcomputer 11 sends a video switching signal to the changeover switch 13. Thereby, the changeover switch 13 is set to a state in which the luminance signal Yout is output as the video signal.
[0059]
In this state, when the lens 1 of the imaging device is directed toward the subject, light from the subject is collected by the lens 1 and passes through the dummy glass 3 and forms an image on the photosensitive portion of the CCD 5. Therefore, an image of light including an infrared component is formed on the photosensitive portion of the CCD 5. The CCD 5 on which the image of the subject is formed on the photosensitive portion converts the formed light into an electrical signal and sends it to the signal processing circuit 6.
[0060]
The signal processing circuit 6 converts the electrical signal received from the CCD 5 into a luminance signal Yout (monochrome signal) and an NTSC composite signal Cout (color signal) and sends them to the changeover switch 13 respectively. At this time, since the changeover switch 13 is set to output the luminance signal Yout, the luminance signal Yout is output to the outside as a video signal.
[0061]
In this black-and-white shooting state, when the car is running toward the imaging device, if the headlight is a halogen lamp, it contains a lot of near-infrared components, so an image of the area irradiated with the headlight and headlight Causes halation, and areas other than the image become dark.
[0062]
As described above, the high luminance detection circuit 14 receives the luminance signal Yout sent from the signal processing circuit 6 and detects a high luminance region in the image formed on the photosensitive portion of the CCD 5. Since the image of the car traveling toward the imaging device has halation in the headlight and the area irradiated with the headlight, the high brightness area detected by the high brightness detection circuit 14 is the headlight and head. This is the area irradiated with light. A shape signal representing the shape of the high luminance region detected by the high luminance detection circuit 14 is sent to the image comparison unit 15.
[0063]
The image comparison unit 15 performs shape recognition by comparing the shape of the high luminance region represented by the shape signal sent from the high luminance detection circuit 14 with the shape stored in advance in the image comparison unit 15. If these shapes are similar, it is detected that the car has traveled toward the imaging device, and an instruction to the transition to the color photographing state is sent to the microcomputer 11. In the color photographing state, the image comparison unit 15 is similar to the shape of the high luminance area represented by the shape signal sent from the high luminance detection circuit 14 and the shape stored in advance in the image comparison unit 15. If it is not, it is detected that the car that has traveled toward the imaging device has passed, and an instruction to the effect that it should transition to the monochrome photography state is sent to the microcomputer 11.
[0064]
The microcomputer 11 that has received an instruction to transition to the color photographing state sends a control signal to the motor 12. As a result, the slide mechanism 4 is driven, and the dummy glass 3 inserted in the optical path from the lens 1 to the CCD 5 is switched to the IR cut filter 2. Further, the microcomputer 11 sends a video switching signal to the changeover switch 13. As a result, the selector switch 13 is switched from the state of outputting the luminance signal Yout from the signal processing circuit 6 as the video signal to the state of outputting the NTSC composite signal Cout. As a result, the light imaged on the photosensitive portion of the CCD 5 does not contain an infrared component, and the video signal output from the imaging device becomes the NTSC composite signal Cout.
[0065]
On the other hand, the microcomputer 11 that has received an instruction to shift to the color photographing state sends a control signal to the motor 12. As a result, the slide mechanism 4 is driven, and the IR cut filter 2 inserted in the optical path from the lens 1 to the CCD 5 is switched to the dummy glass 3. Further, the microcomputer 11 sends a video switching signal to the changeover switch 13. As a result, the changeover switch 13 is switched from the state of outputting the NTSC composite signal Cout from the signal processing circuit 6 to the state of outputting the luminance signal Yout as the video signal. As a result, the light imaged on the photosensitive portion of the CCD 5 includes an infrared component, and the video signal output from the imaging device becomes the luminance signal Yout.
[0066]
As described above, according to the imaging apparatus according to the second embodiment, in the black and white shooting state, the black and white shooting is switched from the black and white shooting to the color shooting based on the shape of the halation area. In this state, it is possible to solve the problem that the headlight and the area irradiated with the headlight cause halation when the car runs toward the image pickup apparatus, making it difficult to see the image.
[0067]
【The invention's effect】
  As described above, according to the present invention,The sunrise time and sunset time calculated by the calculation unit are finely corrected according to the current weather represented by the weather information acquired by the weather information acquisition unit, and the current time is corrected by the fine correction unit.If it is between the sunrise time and the sunset time, an IR cut filter is inserted into the optical path from the lens to the CCD to perform color photography, otherwise a dummy glass is inserted to perform monochrome photography. Therefore, when the light source does not contain a lot of infrared components, the problem that it is difficult to return from black and white photography to color photography even when the surroundings become bright is solved, and switching between color photography and black and white photography can be performed with high accuracy. There is an effect.
[0068]
  According to the present invention, when it is detected that halation has occurred in a state where a dummy glass is inserted in the optical path from the lens to the photosensitive element and black and white photography is performed, an IR cut filter is inserted in the optical path. For color shootingThe control unit includes a high-intensity detection circuit that detects a high-intensity portion based on a signal from the photosensitive element, and the high-intensity portion detected by the high-intensity detection circuit has a predetermined shape And an image comparison unit that detects that halation has occurredSince it is configured as described above, it is possible to quickly switch between color photography and monochrome photography, and the headlight and the area irradiated with the headlight cause halation when the car runs toward the imaging device in the monochrome photography state. This has the effect of resolving the problem of difficult viewing.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a flowchart showing an operation of the microcomputer shown in FIG. 1;
FIG. 3 is a block diagram showing a configuration of an imaging apparatus according to Embodiment 2 of the present invention.
FIG. 4 is a diagram illustrating a shape that commonly appears as a shape of a headlight and a region irradiated by the headlight when a car runs toward the imaging device in the imaging device according to the second embodiment of the present invention. is there.
[Explanation of symbols]
1 lens, 2 IR cut filter, 3 dummy glass, 4 slide mechanism, 5 CCD, 6 signal processing circuit, 7 date information acquisition unit, 8 time information acquisition unit, 9 weather information acquisition unit, 10 status sensor, 11 microcomputer (calculation) Part, control part, fine correction part), 12 motor, 13 changeover switch, 14 high brightness detection circuit (detection part), 15 image comparison part (detection part), Cout NTSC composite signal, Yout brightness signal.

Claims (4)

An IR cut filter that is inserted in an optical path from the lens to the photosensitive element and removes an infrared component from incident light;
A dummy glass inserted into the optical path and allowing incident light to pass through as it is;
A date information acquisition unit for acquiring date information representing the current date;
A time information acquisition unit for acquiring time information representing the current time;
A calculation unit for calculating the sunrise time and the sunset time based on the date information acquired by the date information acquisition unit;
A weather information acquisition unit for acquiring weather information representing the current weather;
A fine correction unit that finely corrects the sunrise time and sunset time calculated by the calculation unit according to the current weather represented by the weather information acquired by the weather information acquisition unit;
If the current time represented by the time information acquired by the time information acquisition unit is between the sunrise time and the sunset time corrected by the fine correction unit, the IR cut filter is inserted into the optical path. A control unit that performs color photography, otherwise inserts the dummy glass and performs monochrome photography. The fine correction unit performs fine correction to delay the sunrise time and advance the sunset time if the current weather represented by the weather information acquired by the weather information unit is not sunny. The imaging apparatus according to claim 1. An IR cut filter that is inserted in an optical path from the lens to the photosensitive element and removes an infrared component from incident light;
A dummy glass inserted into the optical path and allowing incident light to pass through as it is;
A detection unit for detecting whether halation is occurring based on a signal from the photosensitive element;
When the detection unit detects that halation has occurred while the dummy glass is inserted into the optical path and black and white photography is performed, the IR cut filter is inserted into the optical path to perform color photography. A control unit to perform ,
The detector is
A high luminance detection circuit for detecting a high luminance portion based on a signal from the photosensitive element;
An image pickup apparatus comprising: an image comparison unit that detects that the halation has occurred when the high-luminance portion detected by the high-luminance detection circuit has a predetermined shape. The said image comparison part detects that the said halation occurred when the high-intensity part detected by the said high-intensity detection circuit is similar to the shape stored beforehand. Imaging device.

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