JP2000078463A - Image fetching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always provide a satisfactory image in spite of a difference in the luminance of an object. SOLUTION: A controller 7 independently controls storage time T1 and T2 of imaging devices 1 and 2 through a timing generator 74 and can control the time into optimum values. The outputs of the imaging devices 1 and 2 are A/D converted for digital data processing and afterwards, the luminance is put together by a combiner 6. While an automatic mode is selected, the ratio of storage time between the imaging devices 1 and 2 is set so as to provide the combination image of suitable dynamic range corresponding to an object luminance range detected by a luminance range detecting part 10. While a manual mode is selected, on the other hand, the ratio of storage time between the imaging devices 1 and 2 is set so as to provide the combination image intended by a photographer corresponding the mode set, a wide dynamic range priority mode, a picture quality priority mode or an intermediate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image capturing device for capturing a still image or the like as a digital signal, and more particularly to a technology for expanding a dynamic range and improving image quality of a digital still camera while reflecting a photographer's intention.

[0002]

2. Description of the Related Art The smaller the imaging device, the lower the price of the camera can be realized. However, as the number of pixels increases, the size of each pixel decreases, and the dynamic range of the imaging device, which has been lacking in the past, has been increasing. There is also a tendency to run short.

As a solution to this, there is known a method of using a plurality of imaging results with different exposure amounts.

[0004] For example, in Japanese Patent Laid-Open No. Hei 8-223491, FIG.
As shown in FIG. 1, two image sensors A and B are
The amount of light incident on the imaging device is made different, the output of the image sensor with a small amount of incident light is amplified, and the output of the image sensor with a large amount of incident light is combined with the output to realize a wide dynamic range.

As another method, there is known a method in which one image pickup device CCD is used to continuously capture images at different accumulation times as shown in FIG. Describing a specific operation, first, an image is taken in with a long exposure time and temporarily stored in a memory. Subsequently, an image is captured with a short exposure time, combined with the image previously captured and stored in the memory, and combined with an extended dynamic range. (As an example, the paper “Dynamic Range Expansion Method for Car Mount”, IEICE Transactions, October 1995, pp. 1439) The principle of the dynamic range expansion is shown in FIG. Two images with different exposure amounts are captured for a certain subject. At this time, in the high luminance portion, the image with the larger exposure amount is saturated, but the image with the smaller exposure amount is not yet saturated, and is saturated only after the luminance is considerably increased. In consideration of the difference in exposure amount between the two images, an image with a large amount of exposure is used in a low luminance portion, and an image with a small amount of exposure is used in a high luminance portion. As a result, an image with an expanded dynamic range is obtained equivalently.

[0006]

The luminance difference of the subject differs depending on the scene, and varies from a case where the dynamic range of one image pickup device can cover the area (for example, about 400 times or less) to a case where the difference is several thousand times.

[0007] When the difference in brightness between the objects is small, it is better to take an image in a range where the exposure amount of the pair of image sensors does not change much.
A good image in which the boundary of the composition is not noticeable can be composed. On the other hand, when the luminance difference between the subjects is large, it is possible to synthesize a good image having a wide dynamic range by taking a large change in the exposure amount of the pair of image sensors.

However, in the conventional example shown in FIG. 21, since the ratio between the exposure amounts of the pair of image pickup devices is fixed, an image in the fixed subject luminance range is always captured regardless of the luminance difference between the subjects. Therefore, it is not possible to obtain a good image corresponding to the change in the luminance difference of the subject.

Further, in the conventional example shown in FIG. 22, since images are continuously captured, when a moving object is photographed, the image is shifted between a high luminance portion and a low luminance portion.

Accordingly, an object of the present invention is to always obtain a good image irrespective of the luminance difference of a subject.

[0011]

In order to solve the above-mentioned problems, an image capturing apparatus according to the present invention comprises a splitting optical system arranged on an optical axis of an incident light from a subject and splitting an optical path in two directions; The first and second imaging means arranged on the optical axis of one optical path divided by the system and on the optical axis of the other optical path, respectively,
A first selection unit that can select and switch between an automatic mode in which the apparatus automatically sets a predetermined range and a manual mode in which a photographer manually sets a desired range; A subject luminance range detecting means for detecting a certain subject luminance range, an AD converting means for performing an AD conversion on each output of the first and second imaging means, and an output after the AD conversion of the first and second imaging means. Combining means for combining and outputting, and the storage time of image information by the first imaging means and the storage time of image information by the second imaging means, when the automatic mode is selected by the first selection means, Control means for setting in accordance with the subject brightness range detected by the subject brightness range detection means. Accordingly, in the automatic mode in which the dynamic range is automatically controlled, the accumulation time can be set for each of the first and second imaging units according to the brightness difference of the subject, and an image with an appropriate dynamic range can be captured. And a good image corresponding to the luminance difference can be obtained.

Further, another image capturing device of the present invention comprises:
A splitting optical system arranged on an incident optical axis from a subject to split an optical path in two directions, and arranged on an optical axis of one optical path and an optical axis of the other optical path divided by the splitting optical system, respectively. First and second image pickup means, adjustment means for allowing a photographer to manually set a dynamic range of a photographed image to a desired range, and AD conversion of respective outputs of the first and second image pickup means. AD converting means, synthesizing means for synthesizing and outputting the outputs after AD conversion of the first and second imaging means, storage time of image information by the first imaging means, and image information by the second imaging means. And a control means for setting the accumulation time in accordance with the desired range set by the adjustment means. Thereby, the accumulation time can be set for each of the first and second imaging units based on the desired range set by the adjustment unit,
An image having a desired dynamic range can be captured.

According to a preferred aspect, when the automatic mode is selected by the first selecting means, the control means controls the accumulation time T1 of the first imaging means and the accumulation time of the second imaging means. The ratio to T2 (T1 / T2) is selected according to the subject brightness range detected by the subject brightness range detection means.

Further, according to a preferred embodiment, when the photographer manually sets the dynamic range of the photographed image to a desired range, the second selecting means capable of selectively switching the width of the dynamic range is provided. It is characterized by having.

According to a preferred aspect, when the photographer manually sets the dynamic range of the photographed image to a desired range, the dynamic range is selected according to the width of the dynamic range selected by the second selecting means. A ratio (T1 / T2) between the accumulation time T1 of the first imaging means and the accumulation time T2 of the second imaging means is selected.

Further, according to a preferred aspect, a third selecting means for selecting a relative relationship between timings of the accumulation time T1 of the first imaging means and the accumulation time T2 of the second imaging means during the release operation is further provided. The control means controls the first and second imaging means according to a timing selected by the third selection means during a release operation. As a result, it is possible to obtain an image of a moving subject that minimizes the effect of blurring or an image that uses blurring as expression means.

According to a preferred aspect, the object luminance range detecting means is realized by using the first and second image pickup devices themselves, and the accumulation time T1 of the first image pickup device and the second image pickup device To the accumulation time T2 (T1
/ T2) at or above a predetermined value while maintaining the accumulation time T1,
It is characterized in that the subject luminance range is detected by changing T2. Thus, the structure of the image capturing device can be made simple and economical.

According to a preferred aspect, the synthesizing means uses a weighting function that changes continuously with respect to luminance at a luminance overlapping portion where luminance of image information output from the first and second imaging means overlaps. And the weight function changes the shape or parameter according to the subject brightness range when the first selection means selects the automatic mode. This makes it possible to reduce the discontinuity at the boundary when combining the images output from the first and second imaging units in the automatic mode.

Further, according to a preferred aspect, the synthesizing means uses a weighting function that changes continuously with respect to luminance in a luminance overlapping portion where luminance of image information output from the first and second imaging means overlaps. When the photographer manually sets the dynamic range of the captured image to a desired range, the shape or parameter changes according to the set range of the desired range. It is characterized by the following. Accordingly, it is possible to reduce the discontinuity at the boundary when manually setting the dynamic range and combining the images output from the first and second imaging units.

Further, according to a preferred aspect, there is further provided a strobe, a fourth selecting means for selecting a use state of the strobe, and a strobe reaching area identifying means for detecting and identifying an area reached by the strobe in the image. The synthesizing unit performs synthesizing using a weight function that continuously changes with respect to luminance at a luminance overlapping portion of the image information output from the first and second imaging units, and the weight function is The shape or parameter changes according to the result identified by the strobe reach area identification means. As a result, an image with a wide dynamic range can be obtained even when a strobe is used.

Further, according to a preferred embodiment, the apparatus further comprises a strobe and fourth selecting means for selecting a use state of the strobe, wherein the control means automatically stores the first image pickup element when the strobe is used. The first and second imaging elements are controlled so that the time is equal to the accumulation time of the second imaging element, and the synthesizing unit adds the image information output from the first and second imaging units in intensity. By performing the synthesis. Thereby, the image quality can be improved by improving the S / N ratio.

According to a preferred aspect, the synthesizing means performs the synthesizing processing by software processing by a central processing unit constituting the control means.

According to a preferred aspect, the first and second image pickup means are both color image pickup means capable of taking in a full-color image by itself.

According to a preferred aspect, the color imaging means has an on-chip color filter, and the pixels are arranged in the same space, but the color of the on-chip color filter is relatively shifted. It is characterized by being arranged at a spatial position.

According to a preferred aspect, when the first selecting means selects the automatic mode,
An algorithm of combining by the combining means is switched between a case where the subject luminance range is smaller than a predetermined value and a case where the subject luminance range is wider.

According to a preferred aspect, when the synthesizing means manually sets the dynamic range of the photographed image to a desired range by the photographer, the dynamic range selected by the second selecting means is large. The algorithm of the combining by the combining means is switched according to

According to a preferred aspect, both the first and second image pickup means are color image pickup means capable of taking in a full-color image by themselves, and the first selection means selects the automatic mode. In the case where the subject luminance range is narrow, the synthesizing unit performs image synthesis using an algorithm giving priority to false color prevention and resolution improvement, and when the subject luminance range is wide, the synthesizing unit In addition, image synthesis is performed using an algorithm that gives priority to expansion of the dynamic range.

According to a preferred embodiment, both the first and second image pickup means are color image pickup means capable of independently taking in a full-color image, and a photographer manually sets a dynamic range of a photographed image. When the narrow dynamic range is selected by the second selecting means, the synthesizing means performs image synthesis using an algorithm giving priority to false color prevention and resolution improvement. When a wide dynamic range is selected by the second selecting means, the synthesizing means performs the image synthesizing using an algorithm giving priority to the expansion of the dynamic range. This makes it possible to reduce the discontinuity at the boundary when combining the images output from the first and second imaging units.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic principle of the present invention will be briefly described below.

The image capturing apparatus according to the present invention uses two image pickup means (first and second image pickup elements) and varies the ratio of their accumulation time, thereby responding to the luminance difference of the subject. A good image or a desired image according to the photographer's intention can be obtained.

Further, it is possible to prevent the light quantity from being reduced by dividing the light into the two image sensors, and to prevent the difference between the accumulation times (exposure times) T1 and T2 of the first and second image sensors from becoming extremely large. In the range, it is preferable to reduce the light amount distribution to the second image sensor (for example, 1/3 or less) and increase the light amount distribution to the first image sensor (for example, 2/3 or more).
In this case, the ratio of the light quantity distribution between the two becomes twice or more.

When the normal use state, that is, the automatic mode for automatically controlling the dynamic range is selected, the optimal storage time ratio (T1) is automatically set in accordance with the subject luminance detected by the subject luminance range detecting means. / T2) is selected by the camera, and an image with a wide dynamic range is captured for an image with a wide luminance range, and an image with good image quality is captured for an image with a narrow luminance range.

In the above automatic mode, the photographer's intention may not be reflected in some cases. Therefore, a manual mode for manually adjusting the dynamic range can be set.
When such a manual mode is selected, a wide dynamic range priority mode or a narrow dynamic range mode (image quality priority mode) can be further selected.

In the wide dynamic range priority mode, an image having a wide dynamic range can be always obtained by appropriately synthesizing image information, and an image with less black and white loss can be obtained. On the other hand, in the image quality priority mode,
The dynamic range is the same as that of the single-chip image sensor, but by appropriately combining image information, it is possible to obtain an image with few false colors and good resolution.

For reference, a specific example of an algorithm for synthesizing image information output from the first and second image sensors will be described below.

The pixels (x, x) of the image captured under the exposure condition Ei
The output value corresponding to y) is Li (x, y) (where i =
Assuming that 1, 2), the image Lwid (x, y) with the expanded dynamic range is obtained as follows. for i = 1 to i = 2 do for (x, y) = (0,0) to (X-1, Y-1) do if i = 1 then Lwid (x, y) = L1 (x, y) (E2 / E1) γ else if L2 (x, y) <Lsat then Lwid (x, y) = L2 (x, y) where E2 / E1 is an exposure amount ratio of the first and second imaging elements. Γ is a parameter of γ correction, and Lsat
Is the saturation value of the output of the second image sensor.

Next, a synthesizing method using another algorithm will be described. In the above method, discontinuity may occur at the boundary between regions imaged under different exposure conditions. For this reason, in a luminance overlapping area, a method of combining using a weight function that continuously changes with luminance is adopted. In this case, the image Lwid (x, y) is obtained as follows. for i = 1 to i = 2 do for (x, y) = (0,0) to (X-1, Y-1) do if i = 1 then Lwid (x, y) = L1 (x, y) (E2 / E1) γ else Lwid (x, y) = f (L2 (x, y)) L2 (x, y) (E2 / E1) γ + ｛1−f (L2 (x, y))｝ Lwidγ Where f is a weighting function when combining images.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a view for explaining an image capturing apparatus according to a first embodiment. This image capturing device includes a photographing lens 3 for photographing an image of a subject O, an aperture 4 disposed immediately after the photographing lens 3 to adjust the amount of light, and a light path 2 arranged on the optical axis AX.
A spectroscopic mirror 5 which is a split optical system for splitting in the direction, a first image sensor 1 arranged on an optical axis AX1 on one light beam side split by the spectroscopic mirror 5, and a light beam on the other light beam side A second image sensor 2 arranged on the axis AX2, AD converters 21 and 22 for AD converting outputs A1 and A2 of the image sensors 1 and 2, respectively, and AD converters 21 and 2
A synthesizer 6 for synthesizing and outputting the output after AD conversion from 2
And a control device 7 for controlling the operation of each of the image pickup devices 1, 2 and the synthesizer 6, and a changeover switch SW as a selection means for setting the operation state of the control device 7 on the photographer side.

This image capturing device further includes a luminance range detecting section 10 for detecting a luminance range of the subject O, which is a luminance range of the subject O, separately from an optical system for photographing an image of the subject O. The luminance range detection unit 10 includes a second lens 10 a that forms an image of the subject O separately from the photographing lens 3,
A multi-split SPD that is arranged on the optical axis AX ′ of the second lens 10a substantially parallel to the optical axis AX and projects the image of the subject O
(Silicon photodiode) 10b and a low-voltage element connected in parallel to each element constituting the multi-split SPD 10b.
g amplifier 10c. This has the same structure as the multi-photometry sensor for detecting the amount of exposure of the silver halide camera, has a wide detection range, and can measure the luminance range of the subject with one photometry. Based on the output from the luminance range detection unit 10 (that is, the luminance range of the subject), the accumulation time (exposure time) in each of the imaging devices 1 and 2 and the aperture value of the aperture 4 can be determined. Can be used for setting parameters and the like necessary for the synthesis processing in the present embodiment.

The control device 7 controls the operation of the image capturing device as a whole, and has a function of controlling the operation of the synthesizer 6 based on the output of the luminance range detection unit 10 and the setting of the changeover switch SW. CPU 73 (central processing unit), and a timing generator 74 for controlling the accumulation time during imaging by both imaging devices 1 and 2 in accordance with instructions from the CPU 73.

The output V, which is the synthesized image information output from the synthesizer 6 under the control of the control device 7, is input to the image processing device 8 and subjected to various signal processing and compression processing.
Data after image processing from the image processing device 8 is input to the storage device 9 and stored therein. The control device 7
Controls not only the operation of the synthesizer 6 but also the operations of the image processing device 8 and the storage device 9, and allows the image pickup devices 1 and 2 to capture necessary images at appropriate timing based on the instruction of the release operation. This is subjected to appropriate processing such as synthesis, and the obtained image is appropriately stored.

FIG. 2 is a diagram illustrating a specific example of the changeover switch SW. The illustrated changeover switch SW is used to select whether to set the dynamic range of the captured image in the automatic mode or the manual mode, and to select whether to shoot in the wide dynamic range or the image quality in the manual mode. belongs to. Note that the former automatic mode is an operation mode in which the dynamic range of a captured image to be adjusted is automatically set to a predetermined range, and the latter manual mode is an operation mode in which the photographer manually sets the dynamic range to a desired range. is there.

FIG. 2A shows a switch SW1 as first selection means for selecting whether the dynamic range is to be set to the automatic mode or the manual mode, and the photographing mode in the manual mode is set to give priority to a wide dynamic range and image quality. ,
This is an example in which a switch SW2, which is a second selecting means for selecting any one of these intermediates, is provided separately. FIG. 2B collectively shows selection of either the automatic mode or the manual mode, and selection of the shooting mode in the manual mode in which the priority is given to the wide dynamic range, the image quality, and the middle thereof. Switch SW12
This is an example. FIG. 2C shows a selection of an automatic mode or a manual mode while watching a menu displayed on the screen of the liquid crystal display LCD, and a setting of a shooting mode in the manual mode, a wide dynamic range priority, an image quality priority, and the like. This is an example in which selection of any one of those intermediates is made by a pair of command buttons SW3.

When the dynamic range automatic mode is set by the changeover switch SW as shown in FIG. 2, the setting of the changeover switch SW for the manual mode becomes invalid. When the image capturing device is released in a state where the automatic mode is set, the luminance range detecting unit 10 shown in FIG.
The camera automatically selects the optimal storage time value and ratio (T1 / T2) in accordance with the subject luminance range detected by the camera, and outputs an image having a wide dynamic range to an image having a wide luminance range. An image with good image quality is captured for an image with a narrow range.

On the other hand, when the dynamic range manual mode is selected by the changeover switch SW shown in FIG. 2, the photographing mode changeover switch SW is further operated to switch between the wide dynamic range priority mode, the image quality priority mode, and the intermediate mode. Selection becomes possible. At this time, the subject luminance range detection unit 10 operates as an AE sensor for determining the exposure of the image capturing device. Here, when the wide dynamic range priority mode is selected, an image with a wide dynamic range can be always obtained, and an image with less black and white loss can be obtained. On the other hand, in the image quality priority mode, the dynamic range is the same as that of the single image sensor, but a high quality image can be obtained.

The operation of the apparatus shown in FIG. 1 will be described below. Light that has passed through the photographing lens 3 is split by the spectral mirror 5 and projected onto the first image sensor 1 and the second image sensor 2, respectively. At this time, the ratio r1 of the amount of light supplied to the first image sensor 1 and the ratio r2 of the amount of light supplied to the second image sensor 2 have a relationship of r1> r2, and the division ratio r1 /
r2 is a fixed value in the range of 2 to 20.
Further, it is preferable that the division ratio r1 / r2 be a fixed value in the range of 4 to 10. The spectral mirror 5 may be, for example, an optical element having a transmittance and a reflectance different from the original, or may be divided into 50% and 50% using a half mirror having the same transmittance and the reflectance. In this regard, the light amount may be attenuated by a required amount by an ND filter. However, preferably, it is more efficient to use a single spectral mirror 5 without using the ND filter, since there is no light amount loss.

When an instruction to capture an image is issued, the illustrated image capturing apparatus performs a release operation. In particular,
The control device 7 drives the diaphragm 4 by a diaphragm driving device (not shown) to set an optimal illumination light amount. Next, the control device 7 performs exposure for outputting an image signal obtained by operating the first and second imaging elements 1 and 2 to photoelectrically convert the projected image. At this time, the control device 7 can independently control the accumulation times T1 and T2 of the first and second imaging elements 1 and 2 via the timing generator 74 and control them to optimal values. After the outputs of the first and second imaging devices 1 and 2 are AD-converted for digital data processing, the synthesizer 6 synthesizes the luminance. Thereafter, the image processing device 8 performs various signal processing and compression, and the storage device 9 stores the image data after the image processing. In general, prior to photographing, an operation of adjusting the position of the photographing lens 3 and focusing an image of the subject O on the first and second image pickup devices is performed by a focusing device (not shown) or manually. , The description is omitted.

Here, the setting of the ratio of the accumulation time performed for the first and second image pickup devices 1 and 2 will be described. In the case where the automatic mode is selected, in accordance with the subject brightness range detected by the brightness range detection unit 10 (in this case, the brightness difference of the subject O), the second dynamic image is obtained so that a synthesized image of an appropriate dynamic range is obtained. The ratio of the accumulation time performed for the first and second imaging elements 1 and 2 is set. On the other hand, when the manual mode is selected, depending on which of the wide dynamic range priority mode, the image quality priority mode, and the intermediate mode is set, a composite image intended by the photographer is obtained. The ratio of the accumulation time performed for the first and second imaging elements 1 and 2 is set. The ratio (T1 / T) of the accumulation times T1 and T2 in the first and second image sensors 1 and 2
If 2) is appropriately changed according to the set value, the exposure ratio R
Is given by (r1 × T1) / (r2 × T2).

FIG. 3 to FIG. 5 are diagrams for explaining a specific method of performing luminance synthesis by the synthesizer 6 in consideration of the exposure amount ratio R.

FIG. 3 shows a case where the dynamic mode is set to the automatic mode and the brightness difference of the subject is large.
Alternatively, it is a graph for explaining the combination when the dynamic range is set to the manual mode and the wide dynamic range priority mode is selected. FIG. 3A shows the luminance output before the combination, FIG. 3B shows the weight function used in the combination, and FIG. 3C shows the luminance output after the combination. In FIG. 3A, the horizontal axis represents the luminance of the subject O, and the vertical axis represents the outputs A1 and A2 of the imaging devices 1 and 2. In FIG. 3B, the vertical axis indicates the value of a weighting function for synthesizing the output values A1 and A2 of both the imaging devices 1 and 2,
In FIG. 3C, the vertical axis indicates the output V of the synthesizer 6.
In this case, the ratio of the accumulation times T1 and T2 is increased, the overlap area between the linear portions of the photoelectric conversion characteristics of the two imaging elements 1 and 2 is reduced, and information in a wide luminance range can be captured. When the luminance range of the subject O is wide, a wide dynamic range is secured by the above-described combination.

FIG. 4 is a graph for explaining the composition when the brightness difference of the subject is medium in the automatic mode or when the intermediate mode is selected in the manual mode. FIG. 4 (a)
4 shows a luminance output before the combination, FIG. 4B shows a weight function used in the combination, and FIG. 4C shows a luminance output after the combination. In this case, the ratio between the accumulation times T1 and T2 is reduced, and the overlap between the linear portions of the photoelectric conversion characteristics of the two imaging elements 1 and 2 is increased. If the area where the linear portions overlap is large, it is possible to effectively prevent the phenomenon that discontinuity occurs during synthesis. By combining as shown, a wide dynamic range can be ensured, and discontinuity can hardly occur at the joint of combining (image quality and DR priority). If the area where the linear portions overlap is large, the phenomenon that discontinuity occurs during synthesis can be effectively prevented.

FIG. 5 is a graph for explaining the combination when the brightness difference of the subject is small in the automatic mode or when the image quality priority mode is selected in the manual mode. FIG. 5 (a)
Shows the luminance before the combination, FIG. 5B shows the weighting function at the time of the combination, and FIG. 5C shows the luminance after the combination. In this case, by making the accumulation times T1 and T2 equal or making T2 longer than T1 (T1 <T2), the exposure amount ratio R, that is, (r1 × T1) to (r2 × T2)
The ratio of 2) is made close to or equal to 1. The weighting function is simply set to 1, and the outputs of the two image sensors are simply added. As a result, discontinuity due to synthesis does not occur and random noise works in the direction of canceling out,
The image quality is improved (image quality priority).

By providing the synthesizer 6 with a weighting function as an LUT (look-up table), high-speed synthesis processing can be performed. In this case, a plurality of LUTs are prepared in the synthesizer 6 according to the luminance difference and the settings in the manual mode, and the LUTs are switched as necessary to perform synthesis.

Further, an arithmetic circuit comprising a multiplication circuit and an addition circuit can be incorporated in the circuit constituting the synthesizer 6 without using an LUT. In this case, it is possible to perform the combining process by changing the parameters of the weighting function according to the ratio between the accumulation times T1 and T2.

Further, it is also possible to provide a combination by software processing using the arithmetic function of the CPU 73 instead of having a combination circuit for performing special combination processing.

When CCDs are used as the first and second image pickup devices 1 and 2, the second image pickup device 2 (image pickup device for picking up a mirror image reflected by the divided optical system) has a mirror image mode, or It is conceivable to use a CCD dedicated to a mirror image. If such a CCD is used, it is possible to read out pixel outputs at the same spatial position at the same timing even when only one of the mirrors is a mirror image using a split mirror as shown in FIG. Alternatively, a configuration in which a frame memory is provided, information read using a normal CCD is recorded in the above-described frame memory, and information is read in the order in which a mirror image is corrected and image synthesis is performed is also possible.

[Second Embodiment] FIG. 6 is a view for explaining the structure of an image capturing apparatus according to a second embodiment. This image capturing device is a modification of the device of the first embodiment, and the same portions are denoted by the same reference numerals, and redundant description will be omitted. The apparatus according to the present embodiment includes a changeover switch TS as a third selecting means for changing the mode of the exposure timing.
W, and the CPU 73 includes a changeover switch TSW
Controls the timing at which the image signals from the first and second imaging devices 1 and 2 are transferred to the synthesizer 6 based on the setting by the. Further, the apparatus includes first and second imaging devices 1 and 2
A pair of frame memories 121 and 122 for temporarily storing image signals from

FIG. 7 is a diagram showing a specific example of the exposure timing changeover switch TSW. FIG. 7A shows a dedicated switch TSW for setting the mode of the exposure timing.
FIG. 7B shows a liquid crystal display LCD.
In this example, the user selects a mode to set the exposure timing with a pair of command buttons TSW3 while viewing a menu displayed on the screen of FIG. In the example shown,
The exposure timing mode can be set in three ways: end match, start match, and minimum blur.

FIGS. 8 to 10 are diagrams for explaining the exposure timing of the first and second image pickup devices 1 and 2. FIG. In this embodiment, the accumulation timing by the first and second imaging elements 1 and 2 is set to a first mode in which the difference between the center times of the accumulation times T1 and T2 is equal to or less than a predetermined value, and an accumulation start time. Control is performed in three stages, a second mode for matching and a third mode for matching the accumulation end time. The photographer can select a desired mode from these three modes and perform photographing according to the intention.

FIG. 8 is a diagram for explaining the standard exposure timing for minimizing the blur, corresponding to the case where the first mode is selected by the changeover switch TSW. FIG.
8A shows the exposure timing (accumulation timing) of the first image sensor 1 and the signal readout timing, and FIG. 8B shows the exposure timing (accumulation timing) of the second imager 2 and the signal readout timing. At the exposure timing in the first mode, as is clear from the drawing, control is performed so that the difference between the center times of the accumulation times T1 and T2 of the first and second imaging elements 1 and 2 is within a predetermined time. It is optional to set the predetermined time to any value.
It is preferable to set the range to about 100 seconds. Usually, when the focal length of the photographing lens 3 is short, the blur is less noticeable. Therefore, the predetermined time (difference between the center times) may be slightly longer, but when the focal length of the photographing lens 3 is longer, the blur is noticeable. For this reason, the predetermined time is preferably set to be short. By performing such a control method, an image with less blur can be obtained.

FIGS. 9 and 10 show the changeover switch TSW
FIG. 9 is a diagram illustrating a case where the second or third mode is selected and the start and end of exposure by both image sensors 1 and 2 are matched. FIG. 9 is a diagram for explaining exposure timing for matching the start of exposure.
FIG. 9A shows the exposure timing and signal readout timing of the first image sensor 1, and FIG. 9B shows the exposure timing and signal readout timing of the second image sensor 2. on the other hand,
FIG. 10 is a diagram for explaining another exposure timing for matching the end of exposure. FIG. 10A shows the exposure timing and the signal readout timing of the first image sensor 1, and FIG.
(B) shows the exposure timing of the second image sensor 2 and the signal readout timing.

In the case of FIG. 9, it is possible to produce an effect similar to that of a case in which the rear curtain sync photographing (a mode in which the strobe is fired immediately before the shutter is closed) is performed using a strobe with a normal single-lens reflex camera. In the case of FIG. 10, it is possible to produce an effect similar to that in the case of performing first curtain sync shooting (a mode in which a strobe is emitted immediately after the shutter is opened).

Here, as shown in FIGS. 8 and 9, when the exposure end times of the accumulation times T1 and T2 are different (accumulation time T1).
Exposure ends first), and if an image is to be output simultaneously, a time interval is left between the end of exposure of the second image sensor 2 and the end of exposure of the first image sensor 1. . CCD as the first and second imaging devices 1 and 2
In the meantime, the signal charge of the second image sensor 2 is held in the vertical transfer CCD.
In general, a vertical transfer CCD is more affected by a dark current than a photodiode. As a result, the influence of noise due to the dark current component increases. Therefore, in this embodiment, regardless of whether the time difference between the end of exposure by the first and second imaging elements 1 and 2 is large or not, the image signal is read from the second imaging element 2 when the exposure is completed. Temporarily stored in the frame memory 122. Next, when the exposure of the first image sensor 1 is completed, the image signal is read from this and stored in the frame memory 121. After that, the first and second image sensors 1 and 2 stored in both frame memories 121 and 122 are simultaneously read, and the read image signals are synthesized by the synthesizer 6. As a result, it is less likely to be affected by dark current.

[Third Embodiment] FIG. 11 is a view for explaining the structure of an image capturing apparatus according to a third embodiment. This image capturing device is a modified example of the device of the second embodiment, and the same portions are denoted by the same reference numerals and overlapping description will be omitted. The device of the present embodiment includes a connector CNN for connecting the built-in flash FL1 or the detachable external flash FL2. In addition, strobe FL
1. The use state of FL2 is, for example,
A selection switch SSW for selecting from a flash mode in which light emission is prohibited is also provided.

When the forced light emission mode is selected by the selection switch SSW, or when the camera determines that the electronic flash is necessary in the automatic light emission mode, the electronic flash is emitted. At this time, the operation timing of the issuance flashes FL1 and FL2 is
This is linked with the exposure timing changeover switch TSW described in the second embodiment. That is, at the exposure timings shown in FIGS. 8 to 10, during the period in which both the first and second imaging elements 1 and 2 are exposing, the flashes FL1 and FL2 emit light in synchronization with these exposures.

By the way, in the area where the illumination light (strobe light) from the strobes FL1 and FL2 does not reach, as described in the first embodiment, the exposure ratio of the first and second image pickup devices 1 and 2 becomes ( r1 × T1 / r2 × T2). On the other hand, in an area exposed with only the strobe light, the light emission time of the normal strobe is shorter than both the accumulation times T1 and T2.
The exposure ratio of the first and second imaging elements 1 and 2 is simply (r1
/ R2). In the region where both the strobe light and the natural light contribute to the exposure, the exposure ratio is (r1 × T1 / r2 × T
2) and an intermediate value between (r1 / r2). Therefore, simply combining the luminances may cause a problem.

For this purpose, the apparatus according to the present embodiment is provided with identification means for detecting and identifying the area where the strobe light reaches within the image. As a method of realizing such a discriminating means, for example, the flashes FL1 and FL2 are pre-emitted just before the actual photographing, an image is captured by the first and second image sensors 1, 2 and the like, and the brightness of the captured screen is determined based on the brightness of the captured screen. It is assumed that the area where the strobes FL1 and FL2 reach is identified. Then, when performing the actual photographing, the weighting function of the synthesis is referred to by referring to the identification result of the strobe reaching area by the above-described identification means, and also to the luminance difference of each point of the image obtained by the actual photographing. Synthesis is performed while adjusting the shape and parameters of. By doing so, the flashes FL1, F1
Even when using L2, an image with a wide dynamic range can be obtained.

As another control method, regardless of the dynamic range mode and the image quality mode, the strobes FL1, FL
When L2 is used, the exposure times of the first and second imaging elements 1 and 2 can be set to be equal. That is, when using a strobe, T1 is fixed to T2. This way,
The exposure ratio of the two image sensors 1 and 2 is always (r1 / r2) regardless of whether or not the strobe light reaches. In this case, the above-described identification means for identifying the area where the strobe light reaches is not necessary. By synthesizing the captured images, the noise components of the image signals from the two image sensors 1 and 2 are averaged, so that the S / N increases and the image improves.

[Fourth Embodiment] FIG. 12 is a view for explaining the structure of an image capturing apparatus according to a fourth embodiment.

This image reading device is a modified example of the device of the first embodiment, and includes a luminance range detecting section 110 for detecting a subject luminance range using the photographing lens 3.
Further, the apparatus includes a pair of frame memories 121 and 122 for temporarily storing image signals from the first and second image sensors 1 and 2, respectively.

The brightness range detecting section 110 includes a mirror 110a disposed on the optical axis AX for reflecting a part of the image light, and a second lens 10a for condensing the light inverted by the mirror 110a.
And a multi-segment SPD 10b on which light passing through the second lens 10a is projected, and a 1-log amplifier 10c individually connected to the elements of the multi-segment SPD 10b.

The luminance range detecting section 110 also has a function as an AE sensor for determining the exposure time of the image capturing device. Based on the element output from the luminance range detection unit 110, the exposure time of each image sensor 1, 2 and the aperture 4
The aperture value is determined.

When the manual mode is selected with the changeover switch SW for the dynamic range, the information on the subject luminance range obtained from the luminance range detection unit 110 is unnecessary. Therefore, the luminance range detection unit 11
The information about the subject luminance range among the information obtained from 0 is not used, and the luminance range detection unit 110 is used only as an exposure sensor (AE sensor) of the image reading device.

Further, the first and second image pickup devices 1 and 2
It is not necessary to use it exclusively for imaging (image capture), but it can also be used as focus detection (AF) means. For example, when performing CCDAF (mountain climbing AF or the like) or displaying a liquid crystal finder, only one of the two imaging devices 1 and 2 can be operated to cause the control device 7 to perform necessary processing. Which of the imaging devices 1 and 2 is used can be switched according to the brightness of the subject at that time. In this case, the synthesizing unit 6 does not function, and the output of either one of the imaging devices 1 and 2 that is operating is simply passed through. As a result, power consumption can be reduced.

[Fifth Embodiment] FIG. 13 is a view for explaining an image capturing apparatus according to a fifth embodiment. This image reading device is an image pickup device (CCD) for capturing images.
Luminance range detection is performed by using 1 and 2 themselves.

Hereinafter, the operation of the device of this embodiment will be described. First, an image pickup operation for subject luminance detection is performed by the first and second image pickup devices 1 and 2 at accumulation times sufficiently different (for example, T1 / T2 is 10 times or more). Next, the histogram of the output of each of the image sensors 1 and 2 is checked, and the upper limit and the lower limit of the detected luminance range are obtained. The above operation is repeated to optimize the accumulation time.

FIG. 14A shows the distribution of the actual luminance range of the subject, and FIG. 14B shows an example of a change in the subject luminance range that can be detected by the two image sensors 1 and 2. FIG. 14 (b)
In the state at the time (A) of the first stage shown in (1), an area having a higher luminance than the currently detected luminance range exists in the subject. The values of the two accumulation times T1 and T2 are increased by a predetermined amount while maintaining the ratio T1 / T2 in order to feed back the detection results by the two imaging elements 1 and 2, and the histogram is again examined to determine the upper and lower limits of the luminance range. (State at time (B) in the second stage). Repeat this operation,
The luminance range (MAX, MIN) of the subject is detected (third
(See the state at time (C) of the stage). Note that during these operations, instead of reading out all the pixels from the CCDs constituting both the imaging devices 1 and 2, the operation may be such that the pixels of the CCDs are thinned out and read out. At the time of the release operation, when the automatic mode is selected by the changeover switch SW for the dynamic range, the optimum accumulation times T1 and T2 are selected, and when the manual mode is selected by the changeover switch SW, the selected photographing mode is selected. , The storage times T1 and T2 are determined according to the above equation, and a still image is shot. That is, when the automatic mode is selected, the detected object luminance range (MAX, MI
N) and the optimum values of the accumulation times T1 and T2 of the two image sensors 1 and 2 and the ratio T1 / T2 thereof are determined in accordance with the histogram of the luminance of the subject and the distribution of the luminance.
Photographing of a still image is performed with the obtained optimal accumulation times T1 and T2.

[Sixth Embodiment] FIG. 15 is a view for explaining an image capturing apparatus according to a sixth embodiment.

This image reading apparatus uses image pickup devices 101 and 102 composed of color CCDs as image pickup devices for taking in images. In addition, both image sensors 10
Synthesizer 206 for synthesizing the image signals from
Also has an interpolation function.

Two image pickup devices (CCD) 101 and 102
Are relatively located at the same position. That is, a method called pixel shifting, in which pixels are shifted by ピ ッ チ pitch, is not used. Both image sensors 101, 10
2 on-chip type color filters 101a, 10
The arrangement of 2a can be relatively the same position, or the arrangement can be a relatively shifted position.

FIGS. 16 to 18 show the color filters 101a,
It is a figure which illustrates the example of arrangement of 102a notionally. FIG.
FIG. 16A shows an example in which all of the RGB are relatively arranged at the same position. FIG. 16A shows the arrangement of the color filters 101a.
FIG. 16B shows the arrangement of the color filters 102a. FIG.
7 shows an example in which G is arranged at the same position and RB is arranged at a complementary position. FIG. 17A shows the arrangement of the color filter 101a, and FIG. 17B shows the arrangement of the color filter 102a.
FIG. 18 shows an example in which all the RGB components are arranged at relatively shifted positions. FIG. 18A shows the arrangement of the color filters 101a, and FIG. 18B shows the arrangement of the color filters 102a.

In each case, the image capturing is realized by combining the imaging devices 1 and 2 of the Bayer array, but another color filter arrangement or a complementary color filter arrangement may be used.

For example, as shown in FIG. 18, when two Bayer array image pickup devices are combined and the relative positions of the color filters are shifted and used, G is used to obtain information for all pixels.
For R and B, information is obtained at a rate of one pixel for every two pixels.

The following describes the synthesis of color image information with different exposure amounts obtained from the two image pickup devices 1 and 2.

As shown in FIG. 16, when all the RGB components are arranged at the same relative position, the corresponding pixels are simply superimposed with an appropriate weighting function in the same manner as described in the previous embodiments. Is enough. As shown in FIGS. 17 and 18, when there is a relative displacement for at least one of R, G, and B, some contrivance is required in combination and interpolation.

More specifically, first, the gradations of the RGB components are synthesized using pixel outputs spatially adjacent to each other (for example, in the case of the arrangement shown in FIG. 18, R11 and r21 are synthesized, and G21 is synthesized). And g31, G12 and g22 are combined, and B22 and b32 are combined), and RGB interpolation is performed from the combined values obtained in this manner to generate a full-color image (No. Method 1). Or,
First, perform RGB interpolation for each of both images,
Then, the gradation of each of the RGB components may be synthesized for each pixel (second method). Or, first, one second
For each pixel of the image sensor 2, the color component of the corresponding pixel of the first image sensor 1 is interpolated (for example, in the case of the arrangement shown in FIG. 18, r'11, g'21, g of the second image sensor 2). '
12, b′22 are generated by interpolating from the surrounding pixels), and the gradation of each of the RGB components is synthesized with the other first image sensor 1 at the corresponding position after the interpolation (for example, in FIG. 18). In the arrangement shown, R11 and r'11 are synthesized, G21 and g'21 are synthesized, G12 and g'12 are synthesized, and B22 is synthesized.
And b′22), and finally RGB interpolation can be performed again (third method).

It is to be noted that, as in the first method, the amount of calculation is reduced by first performing gradation synthesis processing of each of the RGB colors using spatially adjacent pixels for each color, and then performing RGB interpolation processing. . Conversely, when the tone synthesis processing is performed after the interpolation processing is first performed as in the second method, the required amount of calculation and memory are increased, but the false color and resolution are advantageously reduced. Become. The method of interpolating one image, synthesizing the gradation, and interpolating the synthesized image as in the third method has intermediate features between these.

In this embodiment (in the case of the arrangement shown in FIG. 18), particularly when the luminance range of the subject is narrow, T1 ≒ T
By setting 2 or T1 <T2, it is possible to make the exposure amounts of the two image sensors substantially equal. In this case, G information can be obtained for all the pixels, and R and B information can be obtained at a ratio of one pixel to two pixels. Therefore, the gain adjustment of the two imaging elements 1 and 2 and the RB interpolation processing are performed. As a result, a good image with few false colors and high resolution can be obtained.

Thus, a color image having a wide dynamic range can be obtained when the brightness difference of the subject is large in the automatic dynamic range mode and when the wide dynamic range priority mode is selected in the manual dynamic range mode. On the other hand, when the brightness difference of the subject is small in the dynamic range automatic mode, and when the image quality priority mode is selected in the dynamic range manual mode, when the brightness difference of the subject is small, a good image with few false colors and high resolution is obtained. Obtainable.

Further, as shown in the modification of the third embodiment, the strobes FL1 and FL2 are provided and the strobes FL1 and FL2 are provided.
When the FL2 is used, control is performed so that the exposure times of the two imaging devices 1 and 2 become equal, and an image in which image quality is prioritized can be obtained.

Although the embodiments have been individually described above, it is needless to say that they can be arbitrarily combined. For example, built-in flash FL1
And four selection switches (a switch SW1 for switching a dynamic range mode, a switch SW2 for switching a shooting mode, and a switch T for switching a timing mode).
SW, and a switch SSW for switching the strobe mode, and each can be switched.
A device having a multi-segmented SPD element is used, the image is synthesized by software processing by the CPU 73, and the image pickup devices 1 and 2 can be combined with a color CCD.

Various combinations of the presence / absence of the above four selection switches are also possible. For example, it is also possible to adopt a configuration in which the mode for the dynamic range is exclusively used for manual selection, and the mode is always selected by the switch for switching the shooting mode. In this case, a switch for automatic / manual mode switching of the dynamic range becomes unnecessary, and a switch for selecting a photographing mode remains. Another example is
If the mode for the dynamic range is exclusively for automatic selection, a switch for switching between automatic and manual modes of the dynamic range and a switch for switching between photographing modes are not required. In this case, the configuration includes a switch for switching the timing mode and a switch for switching the strobe mode. Furthermore, a camera that automatically sets all modes according to the situation is also possible. In this case, all four above-mentioned selection switches are unnecessary.

[Seventh Embodiment] FIG. 19 shows an image capturing apparatus according to a seventh embodiment, and shows an example applied to a camera.

The camera 300 includes a diaphragm 4, a beam splitter 5 as a split optical system, a first and a second CCD image pickup device 1, and a housing 300a in which a photographing lens 3 is mounted.
2, the image detection / synthesis circuit 306, and the control device 7. Here, if the image detection / synthesis circuit 306 is described using the image capturing device of the third embodiment shown in FIG.
21 and 122 and a combiner 6 for combining and outputting the output after AD conversion. Further, a liquid crystal display LCD functioning as a finder for a monitor is attached to the back of the housing 300a. The liquid crystal display LCD is also used to select an operation mode of the camera (dynamic range automatic mode, dynamic range manual mode, wide dynamic range priority mode, image quality priority mode, etc.), and a menu displayed on the liquid crystal display LCD is displayed. While watching, the photographer can set the operation state of the control device 7 by the command button SW3.

In this embodiment, the detection of the subject luminance range and the detection of the AF are performed by the first and second image pickup devices 1, 2 comprising CCDs.
The operation is performed by itself, and the liquid crystal display 310 displays a result obtained by combining the outputs of the two imaging elements 1 and 2 with luminance. Thus, a camera capable of obtaining an image with a wide dynamic range can be realized. Further, when both the image pickup devices 1 and 2 are color CCDs, it is possible to realize a camera capable of obtaining an image with few false colors and good resolution. Further, images with a wide dynamic range can be obtained for both moving images and still images. Alternatively, at the time of moving image shooting, shooting is performed in the same manner as a normal video camera using image information of only one image sensor,
Only in the case of a still image, luminance may be synthesized using the image information of both image sensors to obtain a still image with a wide dynamic range.

Incidentally, the method of image synthesis and the like can be achieved by appropriately combining the methods described in the first to sixth embodiments. However, as a method of detecting the subject luminance range and controlling the accumulation time, it is sufficient to perform substantially the same processing as that shown in FIG. 14 and the like. However, in order to support a moving image, feedback control is performed according to the change in the subject luminance range. It is necessary to perform processing to follow the change.

[Eighth Embodiment] FIG. 20 shows an image capturing apparatus according to an eighth embodiment, and shows an example applied to a digital still camera.

The camera 400 has a main body 400a and an interchangeable camera lens 400b. The camera lens 400b is an interchangeable lens for a normal single-lens reflex camera, and is fixed to the main body 400a via a lens mount 400c for a single-lens reflex camera. Camera lens 40
0b passes through the main mirror 401,
A lens 403 corresponding to a portion behind the film surface,
The light is guided to the beam splitter 5 through a re-imaging optical system for reduction composed of a 404 and a fixed mirror 405. On the other hand, the light reflected by the main mirror 401 passes through the focusing screen 410 and the pentaprism 411, passes through the lens 412, and is guided to the optical finder 413.

Note that on the back side of the main mirror 401,
The sub-mirror 420 is arranged, and the AF sensor 421
To perform focus detection. Note that the AF sensor 421 is not limited to the embodiment. For example, in another position A
A sensor for F may be provided, or the imaging devices 1 and 2 may perform AF detection by themselves.

In this embodiment, an AE split sensor 440 is used to detect the subject luminance range, similarly to a normal single-lens reflex camera. Note that the AE sensor 440 is not limited to the embodiment. For example, CC
The configuration may be such that the D image pickup devices 1 and 2 themselves detect the subject luminance range. Switching between automatic mode and manual mode related to the dynamic range is performed by the liquid crystal display LC.
Select with the button while looking at the menu displayed in D.
The liquid crystal display LCD may be a color matrix liquid crystal display capable of displaying images or a black and white liquid crystal display dedicated to mode display.

With such a configuration, an interchangeable lens for a single-lens reflex camera can be used as a lens for a digital still camera, and a wide dynamic range can be obtained by applying the inventions exemplified in the first to sixth embodiments. An image or an image with good resolution with few false colors can be obtained. In addition, since the operation method of the camera itself is exactly the same as that of a normal single-lens reflex camera, operation without a sense of incongruity is possible.

[0102]

As is apparent from the above description, according to the image capturing apparatus of the present invention, in the automatic mode in which the dynamic range is automatically controlled, the first and second image pickup means according to the luminance difference of the subject. By setting an accumulation time for each image, an image with an appropriate dynamic range can be captured, and a good image corresponding to the luminance difference of the subject can be obtained.

Further, according to another image capturing device of the present invention, the first image capturing device can be used based on a desired range set by the adjusting means.
In addition, the accumulation time can be set for each of the second imaging means, and an image having a desired dynamic range can be captured.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image capturing device according to a first embodiment of the present invention.

FIGS. 2A, 2B, and 2C are diagrams illustrating examples of switches for switching between a dynamic range mode and a shooting mode.

FIGS. 3A, 3B, and 3C are diagrams showing a combination in a case where the subject luminance range is wide in the apparatus of FIG. 1;

FIGS. 4A, 4B, and 4C are diagrams illustrating a combination in a case where the subject luminance range is medium in the apparatus of FIG. 1;

FIGS. 5A, 5B, and 5C are diagrams illustrating a combination in a case where the subject luminance range is narrow in the apparatus of FIG. 1;

FIG. 6 is a block diagram illustrating a configuration of an image capturing device according to a second embodiment of the present invention.

FIGS. 7A and 7B are diagrams illustrating an example of a switch for changing an image accumulation timing. FIG.

FIGS. 8A and 8B are explanatory diagrams of exposure and readout timings in the apparatus of FIG. 6 when the difference between the central times of exposure is kept within a predetermined time.

FIGS. 9A and 9B are explanatory diagrams of exposure and readout timings when starting the exposure in the apparatus of FIG. 6;

FIGS. 10A and 10B are explanatory diagrams of exposure and readout timings when the end of exposure is adjusted in the apparatus of FIG. 6;

FIG. 11 is a block diagram illustrating a configuration of an image capturing device according to a third embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of an image capturing device according to a fourth embodiment of the present invention.

FIG. 13 is a block diagram illustrating a configuration of an image capturing device according to a fifth embodiment of the present invention.

FIG. 14 is an explanatory diagram showing a luminance range detection operation in the device of FIG. 14;

FIG. 15 is a block diagram illustrating a configuration of an image capturing device according to a seventh embodiment of the present invention.

FIG. 16 is a diagram showing an example of a color filter arrangement in the device of FIG.

FIG. 17 is a diagram showing another example of a color filter arrangement in the device of FIG.

FIG. 18 is a diagram showing still another example of the color filter arrangement in the device of FIG.

FIG. 19 is a diagram illustrating a configuration of a digital still camera according to an eighth embodiment of the present invention.

FIG. 20 is a diagram illustrating a configuration of a digital still camera according to a ninth embodiment of the present invention.

FIG. 21 is a diagram showing a configuration of a conventional image capturing device.

FIG. 22 is a diagram illustrating another configuration of a conventional image capturing device.

FIG. 23 is a diagram illustrating a method of synthesizing luminance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st image sensor 2 2nd image sensor 3 photographing lens 4 aperture 5 spectral mirror 6 synthesizer 7 control device 10 luminance range detection part 21, 22 converter 62 frame memory 73 CPU 84 defective pixel correction circuit 101a, 102a color filter 110 Luminance range detection element 410 Focusing screen 411 Pentaprism 413 Optical finder 440 AE split sensor LCD Liquid crystal display AX Optical axis O Subject SW, SSW, TSW switch T1, T2 Accumulation time r1, r2 Light intensity division ratio

Claims (19)

[Claims] 1. A split optical system arranged on an incident optical axis from a subject and separating an optical path into two directions, an optical axis of one optical path divided by the split optical system and an optical axis of the other optical path First and second imaging means arranged respectively on the upper side, an automatic mode in which the apparatus automatically sets a dynamic range of a photographed image to a predetermined range, and a manual mode in which a photographer manually sets the dynamic range to a desired range. A first selection unit capable of selecting one of a mode and a switching mode, a subject brightness range detection unit detecting a subject brightness range that is a brightness range of the subject, and an output of each of the first and second imaging units. AD converting means for performing AD conversion; synthesizing means for synthesizing and outputting outputs after AD conversion of the first and second imaging means; storage time of image information by the first imaging means;
Control means for setting an accumulation time of image information by the imaging means according to the subject brightness range detected by the subject brightness range detection means when the automatic mode is selected by the first selection means. An image capturing device characterized by the above-mentioned. 2. A split optical system disposed on an optical axis of an incident light from a subject and separating an optical path in two directions, an optical axis of one optical path and an optical axis of another optical path divided by the split optical system. First and second imaging units respectively disposed above and below; adjusting unit for allowing a photographer to manually set a dynamic range of a captured image to a desired range; and each of the first and second imaging units. AD conversion means for AD-converting the output; synthesizing means for synthesizing and outputting the AD-converted outputs of the first and second imaging means; storage time of image information by the first imaging means;
An image capturing apparatus, comprising: a control unit that sets an accumulation time of image information by an imaging unit according to the desired range set by the adjustment unit. 3. When the automatic mode is selected by the first selection means, the control means determines a ratio (T1) between a storage time T1 of the first imaging means and a storage time T2 of the second imaging means. 2. The image capturing device according to claim 1, wherein / T2) is selected in accordance with the subject luminance range detected by the subject luminance range detection means. 4. When a photographer manually sets a dynamic range of a photographed image to a desired range, the photographer is provided with a second selection unit capable of selectively switching the width of the dynamic range. The image capturing device according to claim 1. 5. When the photographer manually sets the dynamic range of a photographed image to a desired range, the storage of the first image pickup means is performed in accordance with the width of the dynamic range selected by the second selection means. The image capturing device according to claim 4, wherein a ratio (T1 / T2) between a time T1 and an accumulation time T2 of the second imaging unit is selected. 6. A storage time T1 of the first imaging means and a storage time T2 of the second imaging means during a release operation.
And a third selection unit that selects a relative relationship of timing with the control unit, wherein the control unit controls the first and second imaging units according to a timing selected by the third selection unit during a release operation. The image capturing device according to claim 1, wherein: 7. The object brightness range detecting means is realized by using the first and second image pickup devices themselves, and calculates the accumulation time T1 of the first image pickup device and the accumulation time T2 of the second image pickup device. 2. The image capturing apparatus according to claim 1, wherein the storage time range is detected by changing the accumulation times T1 and T2 while maintaining the ratio (T1 / T2) at or above a predetermined value. 8. The synthesizing unit performs synthesizing using a weighting function that continuously changes with respect to luminance at a luminance overlapping portion where luminance of image information output from the first and second imaging units overlaps, and 2. The image capturing device according to claim 1, wherein the weight function changes its shape or parameter according to the subject luminance range when the first selection unit selects the automatic mode. 9. The synthesizing unit performs synthesizing using a weighting function that continuously changes in luminance at a luminance overlapping portion where luminances of image information output from the first and second imaging units overlap, and The weight function is characterized in that, when a photographer manually sets a dynamic range of a captured image to a desired range, a shape or a parameter changes according to the set width of the desired range. The image capturing device according to claim 1. 10. A strobe, fourth selection means for selecting a use state of the strobe, and strobe reach area identification means for detecting and identifying an area reached by the strobe in the image, wherein the synthesizing means is provided. And synthesizing using a weighting function that continuously changes in luminance at a luminance overlapping portion of the image information output from the first and second imaging means, and the weighting function is determined by the strobe reaching area identifying means. 3. The image capturing device according to claim 1, wherein a shape or a parameter changes according to the identified result. 11. A flash further comprising: a strobe; and fourth selection means for selecting a use state of the strobe, wherein the control means includes:
When a strobe is used, the first and second image sensors are automatically controlled so that the accumulation time of the first image sensor and the accumulation time of the second image sensor become equal. 2. The image processing apparatus according to claim 1, wherein the image information output from the second imaging unit is combined by intensity.
The image capturing device according to claim 2. 12. The image capturing apparatus according to claim 1, wherein said synthesizing means performs synthesizing processing by software processing by a central processing unit constituting said control means. 13. The image capturing apparatus according to claim 1, wherein said first and second image capturing means are color image capturing means capable of capturing a full-color image independently. 14. An image capturing apparatus according to claim 2, wherein said first and second image capturing means are both color image capturing means capable of capturing a full-color image by itself. 15. The color imaging means has an on-chip color filter, and pixels are arranged in a relatively same space, but a color of the on-chip color filter is arranged in a relatively shifted space position. The image capturing device according to claim 13, wherein: 16. When the first selection means selects the automatic mode, switching of a combination algorithm by the combination means depending on whether the subject luminance range is narrower or wider than a predetermined value. The image capturing device according to claim 1, wherein: 17. When the photographer manually sets a dynamic range of a photographed image to a desired range, the combining means sets the combining in accordance with the extent of the dynamic range selected by the second selecting means. 5. The method according to claim 4, wherein the combining algorithm is switched.
The image capturing device according to the above. 18. The apparatus according to claim 18, wherein said first and second imaging means are color imaging means capable of individually capturing a full-color image, and wherein said first selection means selects said automatic mode. When the subject brightness range is narrow, the combining unit performs image combining using an algorithm that gives priority to false color prevention and resolution improvement, and when the subject brightness range is wide, the combining unit gives priority to dynamic range expansion. 2. The image capturing device according to claim 1, wherein the image combining is performed using the set algorithm. 19. The first and second imaging means are both color imaging means capable of capturing a full-color image by themselves, and when a photographer manually sets a dynamic range of a photographed image to a desired range. In the above, the second
When a narrow dynamic range is selected by the selecting unit, the synthesizing unit performs image synthesis using an algorithm giving priority to false color prevention and resolution improvement, and a wide dynamic range is selected by the second selecting unit. 5. The image capturing apparatus according to claim 4, wherein when the image data is included, the combining means performs image combining using an algorithm giving priority to dynamic range expansion.