JP5359330B2 - EXPOSURE CONTROL DEVICE AND EXPOSURE CONTROL METHOD - Google Patents

Description

  The present invention relates to an exposure amount control apparatus and an exposure amount control method for obtaining preferable exposure for both a visible light system and an infrared light system when photographing with visible light and infrared light is performed simultaneously.

As described in Patent Document 1 and Patent Document 2, there is known an imaging apparatus that can perform imaging with visible light and imaging with infrared light by one unit, and is used for a surveillance camera or the like. ing. In such an imaging apparatus, under a slightly dark shooting condition such as evening, shooting with infrared light that can clearly show the subject and shooting with visible light that can obtain color information of the subject are performed. Can be done simultaneously.

In the imaging apparatus, exposure control according to the brightness of the subject is performed during imaging. Exposure control is performed by adjusting the EV value determined by mainly aperture and shutter speed. In general, the sensitivity of the image sensor to visible light and the sensitivity to infrared light are different, and the reflectance of visible light and infrared light of the subject are also different. Often the proper exposure does not match For this reason, there is a problem that when exposure control is performed so as to give appropriate exposure to one side, the other side may be underexposed or saturated.

For both perform imaging with the correct exposure, it is preferable to perform exposure control independently for the visible light imaging system and the infrared light image pickup system. Patent Document 1 describes that an aperture value can be independently controlled in a visible light system and an infrared light system by using a diaphragm mechanism that can control light amounts in different wavelength bands. Japanese Patent Application Laid-Open No. H10-228561 describes that independent diaphragm mechanisms for visible light and infrared light are provided at the subsequent stage of the spectroscopic optical system. In this way, by controlling the aperture value independently for the visible light system and the infrared light system, good imaging results can be obtained for both the visible light system and the infrared light system.

JP 2002-369049 A Japanese Patent Laid-Open No. 2005-4181

2. Description of the Related Art In recent years, an electronic shutter system that changes a shutter speed by controlling a time for taking out charge from an image sensor has been widely adopted in an imaging apparatus, and the shutter speed is controlled independently between a visible light system and an infrared light system. This can be easily done without increasing the cost.

  However, in order to control the diaphragm independently between the visible light system and the infrared light system, a diaphragm mechanism capable of controlling the light amounts in different wavelength bands as described in Patent Document 1 is used, or described in Patent Document 2. As described above, it is necessary to provide a plurality of aperture mechanisms, which complicates the configuration and increases the cost of the imaging apparatus. Patent Document 2 also mentions a configuration using only one stop, but does not describe control for obtaining a preferable exposure.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to obtain preferable exposure for both visible light and infrared light systems with a simple configuration when photographing with visible light and infrared light is performed simultaneously.

  In order to solve the above-described problem, an exposure amount control apparatus according to a first aspect of the present invention includes a visible light imaging unit that receives visible light separated from incident light that is incident through a diaphragm unit, and a spectral device that emits light from the incident light. An exposure condition determination unit that determines an appropriate exposure condition for each infrared light imaging unit that receives the infrared light, and an aperture value setting that sets an aperture value of the aperture unit based on the appropriate exposure condition for each A visible light system exposure time setting means for setting an exposure time in the visible light imaging means based on an appropriate exposure condition of the visible light imaging means and the set aperture value, and an infrared light imaging means. Infrared light system exposure time setting means for setting an exposure time in the infrared light imaging means based on appropriate exposure conditions and the set aperture value.

  Here, the aperture value setting means has a range that overlaps between the aperture value range that satisfies the proper exposure condition of the visible light imaging means and the aperture value range that satisfies the appropriate exposure condition of the infrared light imaging means. In this case, the aperture value within the overlapping range is set as the aperture value of the aperture means, and when there is no overlapping range, the aperture that is the most open side that satisfies the proper exposure condition of the visible light imaging unit The aperture value on the further narrowing side among the aperture value and the aperture value on the most open side that satisfies the proper exposure condition of the infrared light imaging means can be set as the aperture value of the aperture means.

  Alternatively, the aperture value setting means has a range that overlaps between the aperture value range that satisfies the appropriate exposure condition of the visible light imaging means and the aperture value range that satisfies the appropriate exposure condition of the infrared light imaging means. Is set as the aperture value of the aperture means in the overlapping range as the aperture value of the aperture means, and when there is no overlapping range, the most open condition that satisfies the proper exposure condition of the visible light imaging means is set. The aperture value on the further narrowing side among the aperture value on the side and the aperture value on the most open side that satisfies the proper exposure condition of the infrared light imaging means may be set as the aperture value of the aperture means. Good.

  In order to solve the above-described problem, an exposure amount control method according to a second aspect of the present invention includes a visible light imaging unit that receives visible light separated from incident light that is incident through a diaphragm unit, and a spectral device that emits light from the incident light. An exposure condition determination step for determining an appropriate exposure condition for each of the infrared light imaging means for receiving the infrared light, and an aperture value setting for setting the aperture value of the aperture means based on the appropriate exposure condition for each A visible light system exposure time setting step for setting an exposure time in the visible light imaging means based on an appropriate exposure condition of the visible light imaging means and the set aperture value; and And an infrared light system exposure time setting step for setting an exposure time in the infrared light imaging means based on appropriate exposure conditions and the set aperture value.

  Here, in the aperture value setting step, there is an overlapping range between the aperture value range that satisfies the proper exposure condition of the visible light imaging unit and the aperture value range that satisfies the appropriate exposure condition of the infrared light imaging unit. In this case, the aperture value within the overlapping range is set as the aperture value of the aperture means, and when there is no overlapping range, the aperture that is the most open side that satisfies the proper exposure condition of the visible light imaging unit The aperture value on the further narrowing side among the aperture value and the aperture value on the most open side that satisfies the proper exposure condition of the infrared light imaging means can be set as the aperture value of the aperture means.

  Alternatively, in the aperture value setting step, there is an overlapping range between an aperture value range that satisfies the proper exposure condition of the visible light imaging unit and an aperture value range that satisfies the appropriate exposure condition of the infrared light imaging unit. Is set as the aperture value of the aperture means in the overlapping range as the aperture value of the aperture means, and when there is no overlapping range, the most open condition that satisfies the proper exposure condition of the visible light imaging means is set. The aperture value on the further narrowing side among the aperture value on the side and the aperture value on the most open side that satisfies the proper exposure condition of the infrared light imaging means is set as the aperture value of the aperture means. Good.

  According to the present invention, it is possible to obtain preferable exposure for both the visible light system and the infrared light system with a simple configuration when photographing with visible light and infrared light is performed simultaneously.

It is a block diagram which shows the structure of the imaging device which concerns on this embodiment. It is a figure which shows the example of the relative intensity with respect to the wavelength for every light source. It is a figure which shows the example of the relative sensitivity with respect to the wavelength of CCD. It is a figure which shows EV value table. It is a flowchart explaining the flow of a process of this embodiment. It is a flowchart explaining the detail of the 1st example of an aperture value setting process. It is a flowchart explaining the detail of the 2nd example of an aperture value setting process. It is a figure which shows the example of the aperture value setting by this embodiment. It is a figure which shows the example of the aperture value setting by this embodiment.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus to which the present invention is applied. This image pickup apparatus is capable of simultaneously shooting with visible light and shooting with infrared light, and includes an image pickup element that receives visible light and an image pickup element that receives infrared light independently. In addition, one common diaphragm mechanism is provided. In this imaging apparatus, the configuration is simplified by preventing the increase in cost by providing a common aperture mechanism for the visible light system and the infrared light system instead of providing them separately.

As shown in the figure, the imaging apparatus 10 includes a photographing optical system 11 having a diaphragm mechanism 12 that adjusts the amount of incident light, a spectral optical system 13 that separates incident light into visible light and infrared light, and separated visible light. The visible light imaging unit 14 that can receive light and can adjust the shutter speed, the infrared light imaging unit 15 that can receive the separated infrared light, and can adjust the shutter speed, and the visible light imaging unit 14 output the light. performs a process to visible light based signal, a visible light signal processor unit 16 for generating the visible light image signal, it performs processing for infrared light system signal output by the infrared imaging unit 15, the infrared light image signal An infrared light signal processing unit 17 to be generated, an exposure control unit 18 that sets an exposure determined by a shutter speed and an aperture value, and an aperture drive unit 19 that drives the aperture mechanism 12 to the set aperture value are provided. Yes.

  The spectroscopic optical system 13 can use a dichroic mirror, a color separation prism, or the like. In the present embodiment, the light is dispersed with a wavelength of 700 nm as a boundary.

  The visible light imaging unit 14 and the infrared light imaging unit 15 include a light receiving element such as a CCD or CMOS and a peripheral circuit. The visible light imaging unit 14 has sensitivity in at least a visible light region, and the infrared light imaging unit 15. Is sensitive to at least the infrared region. In addition, the visible light imaging unit 14 and the infrared light imaging unit 15 can use, for example, an electronic shutter system that changes the shutter speed by controlling the time for taking out charges from the imaging device.

The visible light signal processing unit 16 and the infrared light signal processing unit 17 generate a video signal by performing general signal processing such as γ correction, luminance signal processing, color signal processing, and encoding.

  The exposure control unit 18 determines an appropriate exposure condition for each of the visible light imaging unit 14 and the infrared light imaging unit 15, and the aperture value of the aperture mechanism 12 based on the appropriate exposure condition for each. Based on the aperture value setting unit 23 to be set, the appropriate exposure condition of the visible light imaging unit 14 and the set aperture value, the visible light system shutter speed setting unit 21 for setting the shutter speed in the visible light imaging unit 14, red An infrared light system shutter speed setting unit 22 that sets the shutter speed in the infrared light image capturing unit 15 based on the proper exposure condition of the external light image capturing unit 15 and the set aperture value is provided.

  The exposure condition determination unit 20 can determine the exposure condition using an existing photometry method, for example, overall average photometry. Of course, center-weighted metering, multi-segment metering, or the like may be used. In the entire surface average metering, the average luminance of the entire screen is calculated, and a ratio with a predetermined luminance value at the time of proper exposure is calculated, and a logarithmic value with this value 2 as the base is used as the exposure evaluation value. Here, the luminance value at the time of proper exposure can be 50 IRE for an analog value, and 118/255 for a digital 8-bit. For example, when the average luminance value is digital 59/255, the exposure evaluation value is −1 by the above calculation method. This value is equivalent to the EV value to be corrected so as to obtain an appropriate exposure with respect to the EV value obtained from the aperture value and the shutter speed at the time of photometry.

  Here, as can be seen from the graph of the relative intensity example with respect to the wavelength for each light source shown in FIG. 2, the intensity distribution of the visible light and the infrared light greatly varies depending on the type of the light source. In addition, FIG. 2 has shown the relative intensity example with respect to a wavelength about each of sunlight (FIG. 2 (a)), a fluorescent lamp (FIG.2 (b)), and an incandescent lamp fluorescent lamp (FIG.2 (c)).

  Further, as can be seen from the graph of the relative sensitivity example with respect to the wavelength of the CCD shown in FIG. 3, the sensitivity distribution with respect to the wavelength greatly varies depending on the kind of the CCD. FIG. 3 shows an example of relative sensitivity with respect to wavelength for different types of CCD 1 (FIG. 3A) and CCD 2 (FIG. 3B).

From the above characteristics, in the case of simultaneously recording visible light and infrared light, when exposure control is performed so as to give appropriate exposure to one, the other may be underexposed or saturated. In particular, if it becomes overexposed and becomes saturated, it becomes a so-called whiteout state and cannot be saved by subsequent image processing. This tendency of underexposure and saturation varies depending on the type of light source and the sensitivity of the image sensor as shown in FIGS. 2 and 3, and therefore cannot be controlled uniformly. Therefore, in the present embodiment, exposure control as described below is performed .

First, the exposure possible range of the imaging device 10 will be described. FIG. 4A is a known EV value table, and the exposure possible range of the imaging apparatus 10 is assumed to be the shaded portion of FIG. 4B. That is, the possible aperture values are the open side aperture value F2.0 and the aperture side aperture value F22. Also, the shutter speed on the high speed side was set to 1/4000 seconds, and the shutter speed on the low speed side was set to 1/60 seconds. The imaging device 10 performs exposure control with a combination of these possible aperture values and shutter speeds.

Next, exposure control processing in the present embodiment will be described with reference to the flowchart of FIG. First, at the time of imaging, the exposure condition determination unit 20 calculates an appropriate EV value for the visible light imaging unit 14 (S101). A conventional method can be used to calculate the appropriate EV value. In the present embodiment, photometry is performed using the current aperture value of the aperture mechanism 12 and the current shutter speed of the visible light imaging unit 14, and the exposure evaluation value is calculated according to the above-described procedure. Then, the EV value (see FIG. 4) based on the combination of the aperture value of the aperture mechanism 12 at the time of photometry and the shutter speed of the visible light imaging unit 14 at the time of photometry is corrected by correcting the calculated exposure evaluation value. An EV value can be obtained.

  For example, when the aperture value at the time of photometry is F11 and the shutter speed is 1/1000, and the exposure evaluation value is 0 as a result of visible light photometry, the EV value by the aperture value at the time of photometry and the shutter speed is 17. Since the exposure evaluation value is 0, the appropriate EV value of the visible light imaging unit 14 is 17 + 0 = 17. If the exposure evaluation value of visible light is +1, 17 + (+ 1) = 18 is an appropriate EV value of the visible light imaging unit 14.

  Next, referring to FIG. 4B, candidate aperture values that satisfy the appropriate EV value of the visible light imaging unit 14 are extracted (S102). For example, if the proper EV value is 17, the range of F5.6 to F22 is the aperture candidate value, and if the appropriate EV value is 18, the range of F8 to F22 is the aperture candidate value.

  Similarly for the infrared light system, the exposure condition determination unit 20 calculates an appropriate EV value for the infrared light imaging unit 15 (S103). For example, when the aperture value at the time of photometry is F11 and the shutter speed is 1/1000, and the exposure evaluation value is −2 as a result of infrared photometry, the EV value based on the current aperture value and the shutter speed is 17. Yes, since the exposure evaluation value is −2, the appropriate EV value of the infrared light imaging unit 15 is 17−2 = 15. Then, referring to FIG. 4B, candidate aperture values that satisfy the appropriate EV value of the infrared light imaging unit 15 are extracted (S104).

  Next, the aperture value setting unit 23 sets an aperture value to be applied to the aperture mechanism 12 from the extracted aperture candidate value for the visible light system and the aperture candidate value for the infrared light system (S105). In the present embodiment, a first method and a second method will be described as aperture value setting methods.

  First, the first method for setting the aperture value will be described with reference to the flowchart of FIG. In the first aperture value setting method, it is determined whether or not there is an overlapping range in the aperture candidate values (S201). As a result, when there is an overlapping range (S201: Yes), an aperture value is set within the overlapping range (S202). Here, which aperture value within the overlapping range is to be adopted can be determined according to the situation, the monitoring purpose of the imaging apparatus 10, and the like.

  For example, when the monitoring target is a wide range, the aperture value on the narrowing side can be set within the overlapping range so that the depth of field is deep. In addition, when the movement of the monitoring target is fast, the aperture value on the open side can be set within the overlapping range in order to prevent subject blurring. Since the aperture value in the overlapping range can satisfy the appropriate EV value in both the visible light system and the infrared light system, appropriate exposure can be obtained in both the visible light system and the infrared light system with a simple configuration.

  On the other hand, when there is no overlapping range (S201: No), the larger aperture value (the aperture side) of the minimum F values (open side) of the aperture candidates for the visible light system and the infrared light system is set. (S203). This aperture value is such that one of them satisfies the appropriate EV value and the other becomes as bright as possible to prevent saturation, so that a preferable exposure can be obtained with both a visible light system and an infrared light system with a simple configuration. .

  Next, the second method for setting the aperture value will be described with reference to the flowchart of FIG. Also in the second method of setting the aperture value, it is determined whether there is an overlapping range in the aperture candidate value (S301). As a result, when there is an overlapping range (S301: Yes), an aperture value having the largest F value (narrowing side) within the overlapping range is set (S202). In the second method of setting the aperture value, the influence of lens aberration can be reduced by narrowing as much as possible within the overlapping range. In particular, the influence of lens aberration on the infrared light side having a small refractive index can be suppressed, and an image with high sharpness can be obtained.

  On the other hand, when there is no overlapping range (S301: No), as in the first method, the larger one of the minimum F values (open side) of the aperture candidate values of the visible light system and the infrared light system ( The aperture value on the aperture side is set (S303). This aperture value is such that one of them satisfies the appropriate EV value and the other becomes as bright as possible to prevent saturation, so that a preferable exposure can be obtained with both a visible light system and an infrared light system with a simple configuration. .

Then, according to the set aperture value, the visible light system shutter speed setting unit 21 sets the shutter speed of the visible light imaging unit 14 (S106), and the infrared light system shutter speed setting unit 22 captures the infrared light. The shutter speed of the unit 15 is set (S107). Both shutter speeds can be set by referring to FIG. Specifically, if it is possible to set a shutter speed at which a proper EV can be obtained with a set aperture value, the shutter speed must be set and a shutter speed at which a proper EV can be obtained with the set aperture value must be settable. For example, a shutter speed that is as bright (slow) as possible is set within a settable range. Further, the aperture drive unit 19 drives the aperture mechanism 12 according to the set aperture value (S108), and imaging of the visible light system and the infrared light system is performed simultaneously.

  As described above, the imaging apparatus 10 including the single aperture mechanism 12 sets an aperture value and a shutter speed that give appropriate exposure to both the visible light imaging unit 14 and the infrared light imaging unit 15 as much as possible. If the aperture value and shutter speed that give the right exposure to both sides cannot be obtained, give the right exposure to one of them, prevent saturation of the other, and make the exposure as bright as possible. With such a structure, it is possible to obtain preferable exposure for both the visible light system and the infrared light system.

  Finally, referring to FIG. 8 and FIG. 9, examples of aperture value setting of the present embodiment under various conditions will be described. Here, it is assumed that one of the CCD 1 and the CCD 2 whose sensitivity characteristics are shown in FIG. Further, as described above, it is assumed that the imaging device 10 can set the aperture value in the range of F2.0 to F22.

  FIG. 8A shows an example of aperture value setting when the CCD 1 is used in sunlight, daytime, and sunny conditions. Under this condition, it is assumed that the proper EV value for the visible light system is 17 and the proper EV value for the infrared light system is 15. In the imaging apparatus 10, the aperture value can be set in the range of F2.0 to F22, so the aperture candidate values for the visible light system are F5.6 to F22. Infrared light aperture candidate values are F2.8 to F22. That is, this is a case where an overlapping range exists (S201: Yes, S301: Yes). In this case, according to the first method, any aperture value of F5.6 to F22, which is the overlapping range, can be set (S202). Further, according to the second method, F22, which is the aperture value having the largest F value (narrowing side) within the overlapping range, is set (S202).

  FIG. 8B shows an example of aperture value setting when the CCD 1 is used in sunlight, evening, or cloudy conditions. Under this condition, it is assumed that the proper EV value for the visible light system is 11, and the proper EV value for the infrared light system is 8. At this time, the candidate aperture values for the visible light system are F2.0 to F5.6. Further, the candidate aperture value of the infrared light system is F2. That is, one of them reaches the limit of the aperture value for obtaining an appropriate exposure, and there is only one overlapping aperture value (S201: Yes, S301: Yes). In this case, F2.0 which is an overlap value is set for both the first method and the second method (S202, S302).

  FIG. 8C shows an example of aperture value setting when the CCD 1 is used under a fluorescent lamp. Under this condition, it is assumed that the proper EV value for the visible light system is 15 and the proper EV value for the infrared light system is 8. At this time, the aperture candidate values for the visible light system are F2.8 to F22. Further, the candidate aperture value of the infrared light system is F2. That is, this is a case where there is no overlapping range of aperture candidate values (S201: No, S301: No). In this case, in both the first method and the second method, the smaller one of the minimum F values (visible light system: F2.8, infrared light system: F2) of the respective diaphragm candidate values, whichever is larger (the narrowing side) An aperture value of F2.8 is set (S303).

  FIG. 8D shows an example of aperture value setting when the CCD 1 is used under an incandescent lamp. Under this condition, it is assumed that the appropriate EV value for the visible light system is 15 and the appropriate EV value for the infrared light system is 15. At this time, the aperture candidate values are F2.8 to F22 for both the visible light system and the infrared light system. That is, it is a case (S201: Yes, S301: Yes) where both appropriate EV values match and an overlapping range exists. In this case, according to the first method, any aperture value of F2.8 to F22, which is the overlapping range, can be set (S202). Further, according to the second method, F22, which is the aperture value having the largest F value (narrowing side) within the overlapping range, is set (S202).

  FIG. 9A shows an example of aperture value setting when the CCD 2 is used in sunlight, daytime, and sunny conditions. Under this condition, it is assumed that the proper EV value for the visible light system is 17 and the proper EV value for the infrared light system is 18. At this time, the aperture candidate values for the visible light system are F5.6 to F22. Infrared light aperture candidate values are F8 to F22. That is, the infrared light system has a larger appropriate EV value and an overlapping range exists (S201: Yes, S301: Yes). In this case, according to the first method, any aperture value of F8 to F22 that is the overlapping range can be set (S202). Further, according to the second method, F22, which is the aperture value having the largest F value (narrowing side) within the overlapping range, is set (S202).

  FIG. 9B is an example of aperture value setting when the CCD 2 is used in sunlight, evening, or cloudy conditions. Under this condition, it is assumed that the proper EV value of the visible light system is 11, and the proper EV value of the infrared light system is 11. At this time, the aperture candidate values are F2.0 to F5.6 for both the visible light system and the infrared light system. That is, it is a case (S201: Yes, S301: Yes) where both appropriate EV values match and an overlapping range exists. In this case, according to the first method, any aperture value of F2.0 to F5.6 that is the overlapping range can be set (S202). Further, according to the second method, F5.6, which is the aperture value with the largest F value within the overlapping range (narrowing side), is set (S202).

  FIG. 9C shows an example of aperture value setting when the CCD 2 is used under a fluorescent lamp. Under this condition, it is assumed that the proper EV value for the visible light system is 15 and the proper EV value for the infrared light system is 11. At this time, the aperture candidate values for the visible light system are F2.8 to F22. Further, the aperture candidate values of the infrared light system are F2 to F5.6. That is, this is a case where an overlapping range exists (S201: Yes, S301: Yes). In this case, according to the first method, any aperture value of F2.8 to F5.6, which is the overlapping range, can be set (S202). Further, according to the second method, F5.6, which is the aperture value with the largest F value within the overlapping range (narrowing side), is set (S202).

  FIG. 9D is an example of aperture value setting when the CCD 2 is used under an incandescent lamp. Under this condition, it is assumed that the proper EV value for the visible light system is 14 and the proper EV value for the infrared light system is 17. At this time, the aperture candidate values for the visible light system are F2.0 to F16. Infrared light aperture candidate values are F5.6 to F22. That is, the infrared light system has a larger appropriate EV value and an overlapping range exists (S201: Yes, S301: Yes). In this case, according to the first method, any aperture value of F5.6 to F16, which is the overlapping range, can be set (S202). Further, according to the second method, F16, which is the aperture value with the largest F value (narrowing side) within the overlapping range, is set (S202).

DESCRIPTION OF SYMBOLS 10 ... Imaging device 11 ... Imaging optical system 12 ... Aperture mechanism 13 ... Spectral optical system 14 ... Visible light imaging part 15 ... Infrared light imaging part 16 ... Visible light system signal processing part 17 ... Infrared light system signal processing part 18 ... Exposure control unit 19 ... Aperture drive unit 20 ... Exposure condition determination unit 21 ... Visible light system shutter speed setting unit 22 ... Infrared light system shutter speed setting unit 23 ... Aperture value setting unit

Claims (4)

Appropriate exposure conditions are determined for each of the visible light imaging means for receiving visible light split from incident light incident through the aperture means and the infrared light imaging means for receiving infrared light split from the incident light. Exposure condition determination means;
An aperture value setting means for setting an aperture value of the aperture means based on the appropriate exposure condition for each of the above,
A visible light system exposure time setting means for setting an exposure time in the visible light imaging means based on the appropriate exposure condition of the visible light imaging means and the set aperture value;
Infrared light exposure time setting means for setting an exposure time in the infrared light imaging means based on the appropriate exposure condition of the infrared light imaging means and the set aperture value ,
When the aperture value setting means has a range that overlaps between the aperture value range that satisfies the proper exposure condition of the visible light imaging means and the aperture value range that satisfies the appropriate exposure condition of the infrared light imaging means, The aperture value within the overlapping range is set as the aperture value of the aperture means,
When there is no overlapping range, the aperture value that is the most open side that satisfies the appropriate exposure condition of the visible light imaging unit, and the aperture value that is the most open side that satisfies the appropriate exposure condition of the infrared light imaging unit, 2. An exposure amount control apparatus according to claim 1, wherein an aperture value closer to the aperture is set as an aperture value of the aperture means . Appropriate exposure conditions are determined for each of the visible light imaging means for receiving visible light split from incident light incident through the aperture means and the infrared light imaging means for receiving infrared light split from the incident light. Exposure condition determination means;
An aperture value setting means for setting an aperture value of the aperture means based on the appropriate exposure condition for each of the above,
A visible light system exposure time setting means for setting an exposure time in the visible light imaging means based on the appropriate exposure condition of the visible light imaging means and the set aperture value;
Infrared light exposure time setting means for setting an exposure time in the infrared light imaging means based on the appropriate exposure condition of the infrared light imaging means and the set aperture value,
When the aperture value setting means has a range that overlaps between the aperture value range that satisfies the proper exposure condition of the visible light imaging means and the aperture value range that satisfies the appropriate exposure condition of the infrared light imaging means, , Set the aperture value that is closest to the aperture within the overlapping range as the aperture value of the aperture means,
When there is no overlapping range, the aperture value that is the most open side that satisfies the appropriate exposure condition of the visible light imaging unit, and the aperture value that is the most open side that satisfies the appropriate exposure condition of the infrared light imaging unit, An exposure amount control apparatus characterized in that an aperture value closer to the aperture is set as an aperture value of the aperture means. Appropriate exposure conditions are determined for each of the visible light imaging means for receiving visible light split from incident light incident through the aperture means and the infrared light imaging means for receiving infrared light split from the incident light. An exposure condition determination step;
An aperture value setting step for setting an aperture value of the aperture means based on the appropriate exposure condition for each of the above,
A visible light system exposure time setting step for setting an exposure time in the visible light imaging means based on an appropriate exposure condition of the visible light imaging means and the set aperture value;
An infrared light exposure time setting step for setting an exposure time in the infrared light imaging means based on the appropriate exposure condition of the infrared light imaging means and the set aperture value;
When the aperture value setting step includes a range that overlaps between the aperture value range that satisfies the proper exposure condition of the visible light imaging unit and the aperture value range that satisfies the appropriate exposure condition of the infrared light imaging unit, , sets the aperture value in the range of the overlapped as the aperture value of the aperture means,
When there is no overlapping range, the aperture value that is the most open side that satisfies the appropriate exposure condition of the visible light imaging unit, and the aperture value that is the most open side that satisfies the appropriate exposure condition of the infrared light imaging unit, An aperture value control method , wherein an aperture value closer to the aperture is set as an aperture value of the aperture means. Appropriate exposure conditions are determined for each of the visible light imaging means for receiving visible light split from incident light incident through the aperture means and the infrared light imaging means for receiving infrared light split from the incident light. An exposure condition determination step;
An aperture value setting step for setting an aperture value of the aperture means based on the appropriate exposure condition for each of the above,
A visible light system exposure time setting step for setting an exposure time in the visible light imaging means based on an appropriate exposure condition of the visible light imaging means and the set aperture value;
The infrared light based on the proper exposure condition and the set diaphragm value of the imaging means, have a infrared light system exposure time setting step of setting an exposure time in the infrared light imaging means,
When the aperture value setting step includes a range that overlaps between the aperture value range that satisfies the proper exposure condition of the visible light imaging unit and the aperture value range that satisfies the appropriate exposure condition of the infrared light imaging unit, , Set the aperture value that is closest to the aperture within the overlapping range as the aperture value of the aperture means,
When there is no overlapping range, the aperture value that is the most open side that satisfies the appropriate exposure condition of the visible light imaging unit, and the aperture value that is the most open side that satisfies the appropriate exposure condition of the infrared light imaging unit, A method of controlling an exposure amount , wherein an aperture value on a further narrowing side is set as an aperture value of the aperture means .