JP3949830B2 - Camera subject selection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for selecting a subject to be subjected to focus adjustment or exposure control from a plurality of objects included in a screen to be photographed.
[0002]
[Prior art]
In photography, for example, when two people are included in the screen observed from the viewfinder and you want to focus on the person in front of them, or when the subject image is exposed because the background is too bright due to backlighting, etc. You may want to prevent the shortage. The former can be solved by focus lock, change the camera direction so that the person in front is in the center of the viewfinder screen, secure the in-focus state, then return the camera to the original position and release the shutter. . In the latter case, it is only necessary to perform backlight correction and operate the exposure correction switch so that the exposure of the subject image becomes an appropriate value.
[0003]
[Problems to be solved by the invention]
Operations such as focus lock and backlight correction are not simple, and there is a problem that a certain level of skill is required.
[0004]
An object of the present invention is to make it possible to easily perform these operations by selecting a subject to be subjected to operations such as focus lock or backlight correction.
[0005]
[Means for Solving the Problems]
The subject selection device for a camera according to the present invention receives a light source that irradiates distance measuring light onto a plurality of objects included in a screen to be photographed, and reflected light from the plurality of objects, and accumulates charges according to the amount of received light. An image sensor having a large number of photoelectric conversion elements, and three-dimensional information for detecting three-dimensional information that is the distance from the camera to each point on the surface of a plurality of objects by integrating signal charges in the photoelectric conversion elements It is characterized by comprising a detection means and a subject selection means for obtaining a distance histogram and selecting a subject to be photographed from a plurality of objects based on the histogram.
[0006]
The three-dimensional information detection means, for example, includes a signal charge holding unit provided adjacent to the photoelectric conversion element, and sweeps unnecessary charges accumulated in the photoelectric conversion element from the photoelectric conversion element to stop the operation thereof. Stored charge sweeping means for starting the signal charge accumulation operation in the signal, signal charge transfer means for transferring the signal charge accumulated in the photoelectric conversion element to the signal charge holding unit, accumulated charge sweeping means and signal charge transfer means, And signal charge integration means for integrating the signal charge in the signal charge holding unit by alternately driving.
[0007]
The photoelectric conversion element is preferably a charge storage type. The photoelectric conversion element is formed along the substrate, for example, and the accumulated charge sweeping unit sweeps unnecessary charges to the substrate side. Preferably, the signal charge holding unit is a vertical transfer unit for outputting the signal charge to the outside of the three-dimensional image detection unit. The photoelectric conversion element and the signal charge holding unit are configured as, for example, an interline CCD having a vertical overflow drain structure.
[0008]
Preferably, the charge sweep signal output by the accumulated charge sweeping means for sweeping unnecessary charges and the charge transfer signal output by the signal charge transfer means for transferring the signal charge are pulse signals, respectively. . In this case, the pulsed ranging light having a predetermined pulse width is output by the light source, and the ranging light pulse is generated during the charge accumulation period from the output of the charge sweep signal to the output of the charge transfer signal. By being output, the signal charge corresponding to the three-dimensional information is integrated in the signal charge holding unit.
[0009]
The subject selection means selects, for example, a subject to be photographed based on the maximum peak value of the histogram. The subject selecting means may select a subject to be photographed based on a ratio of a plurality of peak values included in the histogram. The subject selecting means may select an object corresponding to one of a plurality of peak values included in the histogram as a subject to be photographed.
[0010]
The subject selection device of the camera preferably includes automatic focus adjustment means for performing automatic focus adjustment on a subject to be photographed, or automatic exposure control means for performing automatic exposure control on a subject to be photographed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a camera provided with a subject selection device according to a first embodiment of the present invention.
[0012]
On the front surface of the camera body 10, a finder window 12 is provided at the upper left of the taking lens 11, and a strobe 13 is provided at the upper right. On the upper surface of the camera body 10, a light emitting device (light source) 14 that irradiates laser light that is distance measuring light is disposed directly above the photographing lens 11. A release switch 15 and a liquid crystal display panel 16 are provided on the left side of the light emitting device 14, and a mode switching dial 17 is provided on the right side. The mode switching dial 17 is used to switch the photographing operation mode of the camera among an aperture priority mode, a shutter speed priority mode, a program photographing mode, and the like.
[0013]
FIG. 2 is a block diagram showing a circuit configuration of the camera shown in FIG.
A diaphragm 25 is provided in the photographic lens 11. The opening degree of the diaphragm 25 is adjusted by the iris drive circuit 26. The focus adjustment operation and zooming operation of the photographic lens 11 are controlled by the lens driving circuit 27.
[0014]
A first mirror 31 is provided behind the photographic lens 11 (on the right side in the drawing), and a second mirror 32 is provided further behind the first mirror 31. The first mirror 31 is a half mirror, and the second mirror is a total reflection mirror. Each of these mirrors 31 and 32 can rotate between an inclined position indicated by a solid line and a horizontal position indicated by a broken line.
[0015]
A finder 33 is provided above the first mirror 31, and the finder 33 includes a focus plate 34, a liquid crystal panel 35, and an eyepiece lens 36. The focus plate 34 and the liquid crystal panel 35 are overlapped with each other, and are provided at positions where the first mirror 31 in the horizontal position faces. The eyepiece 36 is provided in the finder 33 on the side opposite to the focus plate 34 and the liquid crystal panel 35.
[0016]
The liquid crystal panel 35 is controlled by a liquid crystal panel driving circuit 37, whereby each liquid crystal cell is independently switched between a state in which light is transmitted and a non-transmitted state in which transmission of light is suppressed. When the first mirror 31 is in the inclined position, an image obtained through the photographing lens 11 is formed on the focus plate 34. Of the image, the portion corresponding to the transparent portion of the liquid crystal panel 35 is clearly observed through the eyepiece lens 36, but the portion corresponding to the non-transmissive portion of the liquid crystal panel 35 is displayed darkly. On the other hand, when the first mirror 31 is in the horizontal position, nothing is imaged on the focus plate 34. The liquid crystal panel drive circuit 37 is controlled by the imaging signal processing circuit 47 based on the distance measurement result, as will be described later.
[0017]
An imaging device (CCD) 38 is provided below the second mirror 32, and a shutter 41 is provided behind the second mirror 32. A film 42 for recording a photographed image is disposed behind the shutter 41. The CCD 38 can detect an image for one screen obtained by the photographing lens 11, that is, the same image as the image guided to the film 42, and is used for distance measurement. That is, when the second mirror 32 is in the inclined position, an image obtained by the photographing lens 11 is formed on the CCD 38, and distance measurement is performed using this image, and the distance from the camera to each point on the surface of the subject. The three-dimensional information is detected. On the other hand, when the second mirror 32 is in the horizontal position, the light passing through the photographing lens 11 is guided to the film 42 by opening the shutter 41, and an image is recorded. The opening / closing operation of the shutter 41 is controlled by a shutter driving circuit 43.
[0018]
A light emitting element control circuit 52 is connected to the system control circuit 51. The light emitting device 14 includes a light emitting element 14 a and an illumination lens 14 b, and the light emitting operation of the light emitting element 14 a is controlled by the light emitting element control circuit 52. The light emitting element 14a irradiates laser light that is distance measuring light, and this laser light is applied to the subject through the illumination lens 14b. The light reflected from the subject enters the photographing lens 11. The distance is measured by detecting this light by the CCD 38.
[0019]
In ranging, charges corresponding to the formed image are generated in a large number of photoelectric conversion elements provided in the CCD 38. Operations such as charge accumulation operation and charge read operation in the CCD 38 are controlled by the CCD drive circuit 44. The charge signal read from the CCD 38, that is, the image signal is amplified by the amplifier 45 and converted from an analog signal to a digital signal by the A / D converter 46. The digital image signal is subjected to processing such as noise reduction in the imaging signal processing circuit 47 and temporarily stored in the three-dimensional information memory 48.
[0020]
The iris drive circuit 26, the lens drive circuit 27, the shutter drive circuit 43, the CCD drive circuit 44, and the imaging signal processing circuit 47 are controlled by the system control circuit 51. The system control circuit 51 is connected to a switch group 53 including a release switch 15, a mode switching dial 17, and a manual selection switch 18, and a liquid crystal display panel 16 for displaying a photographing operation mode of the camera.
[0021]
The principle of distance measurement in this embodiment will be described with reference to FIGS. In FIG. 4, the horizontal axis represents time t.
[0022]
The distance measuring light output from the distance measuring device B is reflected by the subject S and received by a CCD (not shown). The distance measuring light is pulsed light having a predetermined pulse width H. Therefore, the reflected light from the subject S is also pulsed light having the same pulse width H. The rising edge of the reflected light pulse is delayed by a time δ · t (where δ is a delay coefficient) from the rising edge of the ranging light pulse. Since the distance measuring light and the reflected light have traveled a distance r twice that between the distance measuring device T and the subject S, the distance r is
r = δ · t · C / 2 (1)
Is obtained. However, C is the speed of light.
[0023]
For example, when the reflected light is detected from the rising edge of the ranging light pulse and switched to the undetectable state before the reflected light pulse falls, that is, when the reflected light detection period T is provided, The received light amount A in the reflected light detection period T is a function of the distance r. That is, the received light amount A decreases as the distance r increases (the time δ · t increases).
[0024]
In the present embodiment, using the principle described above, the object S is detected from the camera body 10 by detecting the received light amount A by a plurality of photodiodes (photoelectric conversion elements) provided in the CCD 38 and arranged two-dimensionally. The distance to each point on the surface is detected, and three-dimensional image data relating to the surface shape of the subject S is input together.
[0025]
FIG. 5 is a diagram illustrating the arrangement of the photodiode 61 and the vertical transfer unit 62 provided in the CCD 38. FIG. 6 is a cross-sectional view showing the CCD 38 cut along a plane perpendicular to the substrate 63. The CCD 38 is a conventionally known interline CCD, and uses a VOD (vertical overflow drain) system for sweeping out unnecessary charges.
[0026]
The photodiode 61 and the vertical transfer unit (signal charge holding unit) 62 are formed along the surface of the n-type substrate 63. The photodiodes 61 are two-dimensionally arranged in a grid pattern, and the vertical transfer units 62 are provided adjacent to the photodiodes 61 arranged in a line in a predetermined direction (vertical direction in FIG. 5). The vertical transfer unit 62 has four vertical transfer electrodes 62 a, 62 b, 62 c, 62 d for one photodiode 61. Therefore, in the vertical transfer section 62, wells having four potentials can be formed, and signal charges can be output from the CCD 38 by controlling the depths of these wells as conventionally known. The number of vertical transfer electrodes can be freely changed according to the purpose.
[0027]
A photodiode 61 is formed in a p-type well formed on the surface of the substrate 63, and the p-type well is completely depleted by a reverse bias voltage applied between the p-type well and the n-type substrate 63. In this state, charges corresponding to the amount of incident light (reflected light from the subject) are accumulated in the photodiode 61. When the substrate voltage Vsub is increased to a predetermined value or more, the charge accumulated in the photodiode 61 is swept out to the substrate 63 side. On the other hand, when a charge transfer signal (voltage signal) is applied to the transfer gate unit 64, the charge accumulated in the photodiode 61 is transferred to the vertical transfer unit 62. That is, after the charge is swept to the substrate 63 side by the charge sweep signal, the signal charge accumulated in the photodiode 61 is transferred to the vertical transfer unit 62 side by the charge transfer signal, thereby realizing a so-called electronic shutter operation.
[0028]
FIG. 7 is a timing chart of a three-dimensional information detection operation for detecting data related to the distance to each point on the surface of the subject. The three-dimensional information detection operation will be described with reference to FIGS. 1, 2, and 5 to 7.
[0029]
A charge sweep signal (pulse signal) S2 is output in synchronism with the output of the vertical synchronization signal S1, whereby the unnecessary charges accumulated in the photodiode 61 are swept in the direction of the substrate 63. The light emitting device 14 is activated simultaneously with the end of the output of the charge sweep signal S2, and pulsed ranging light S3 having a constant pulse width is output. The distance measuring light S3 is reflected by the subject and enters the CCD 38. That is, the CCD 38 receives the reflected light S4 from the subject. When a certain period of time has elapsed from the output of the distance measuring light S3, a charge transfer signal (pulse signal) S5 is output, whereby the charges accumulated in the photodiode 61 are transferred to the vertical transfer unit 62. The charge transfer signal S5 is output before the end of the distance measuring light output.
[0030]
Thus, the period T from the end of the output of the charge sweep signal S2 to the start of the output of the charge transfer signal S5. _U1 During this time, signal charges corresponding to the distance to the subject are accumulated in the photodiode 61. That is, the period T during which the ranging light S3 is output. _S And charge accumulation period T _U1 Start simultaneously, but the charge accumulation period T _U1 This process ends earlier, and only part of the reflected light S4 is detected by the CCD 38, and the signal charge S6 generated by the detected light corresponds to the distance to the subject. In other words, out of the reflected light S4 from the subject, the charge accumulation period T _U1 A signal charge S 6 corresponding to the light reaching the photodiode 61 is accumulated in the photodiode 61. The signal charge S6 is transferred to the vertical transfer unit 62 by the charge transfer signal S5. The output period T of the distance measuring light S3 _S Is the charge accumulation period T _U1 You may start earlier.
[0031]
After a predetermined time has elapsed from the output of the charge transfer signal S5, the charge sweep signal S2 is output again, and unnecessary charges accumulated in the photodiode 61 after the transfer of the signal charge to the vertical transfer unit 62 are swept in the direction of the substrate 63. Is issued. That is, signal charge accumulation is newly started in the photodiode 61. Then, as described above, the charge accumulation period T _U1 When elapses, the signal charge is transferred to the vertical transfer unit 62.
[0032]
The transfer operation of the signal charge S6 to the vertical transfer unit 63 is repeatedly executed until the next vertical synchronization signal S1 is output. As a result, the signal charge S6 is integrated in the vertical transfer unit 62, and the signal charge S6 integrated in a period of one field (a period sandwiched between two vertical synchronization signals S1) is considered that the subject is stationary during that period. If it is thin, it corresponds to the three-dimensional information of the subject.
[0033]
The detection operation of the signal charge S6 described above relates to one photodiode 61, and such a detection operation is performed in all the photodiodes 61. As a result of the detection operation in the period of one field, the three-dimensional information detected by the photodiode 61 is held in each part of the vertical transfer unit 62 adjacent to each photodiode 61. This three-dimensional information is output from the CCD 38 by a vertical transfer operation in the vertical transfer unit 62 and a horizontal transfer operation in a horizontal transfer unit (not shown).
[0034]
8 and 9, using the above-mentioned distance measurement principle, one is selected from a plurality of subjects included in the screen to be photographed, and the subject is photographed by performing automatic focus adjustment and automatic exposure control. It is a flowchart of the program for.
[0035]
In step 101, parameter n is set to zero. In step 102, it is determined whether or not the release switch 15 has been half-pressed, that is, whether or not the photometric switch has been set to the on state. When the release switch 15 is half-pressed, the routine proceeds to step 103 where distance measurement is performed.
[0036]
In step 103, the light emitting device 14 and the CCD 38 are driven, and three-dimensional information related to all objects included in the screen to be photographed is detected. That is, the distance to each point up to the object is detected by each photodiode of the CCD 38 and stored in the three-dimensional information memory 48. In step 103, a distance-related histogram as shown in FIG. 10, for example, is created based on the three-dimensional information. In this histogram, the horizontal axis indicates the distance from the camera to each point on the surface of the object, and the vertical axis indicates the number of pixels corresponding to the distance, that is, the number of photodiodes that have detected the distance. In other words, the histogram shows the appearance frequency of the photodiode that outputs a signal of the distance for each distance.
[0037]
In step 104, the largest peak value H in the distance histogram ₁ Distance D ₁ Is determined as the significant distance Da corresponding to the subject to be photographed. In step 105, it is determined whether or not the significant distance Da is infinity, that is, whether 1 / Da≈0. When the significant distance Da is at infinity, that is, when most of the image obtained by the CCD 38 is at an infinite distance, the significant distance Da does not indicate the distance to the subject to be actually photographed. As a result, the significant distance Da is reset in steps 106 to 108.
[0038]
In step 106, the second largest peak value H in the histogram ₂ Distance D ₂ Is required. In step 107, the ratio (H ₂ / H ₁ ) Is larger than a predetermined value (for example, a value of 1 or less). This ratio is the distance D on the screen being shot. ₂ Indicates the ratio of the subject image to the background at infinity. When the ratio is greater than a predetermined value, the subject to be photographed is the distance D ₂ At step 108, the distance D ₂ Is defined as the significant distance Da. In step 107, the value H ₂ It may be determined whether the ratio of (pixel number) to the total number of pixels in one screen is greater than a predetermined value.
[0039]
In step 111, automatic focus adjustment is performed on the subject to be photographed, the photographing lens 11 is driven and displaced in the optical axis direction, and the focal point is adjusted to the significant distance Da. In step 112, the CCD 38 is driven, and the luminance value of each pixel is detected using a photodiode corresponding to the significant distance Da. Then, photometry is performed by integrating these luminance values, that is, the luminance value of the image of the subject to be photographed, and the exposure conditions of the aperture and shutter speed at the time of photographing are obtained. That is, in step 112, automatic exposure control is performed.
[0040]
In step 113, the depth of field Δd is obtained from the exposure condition (that is, the aperture) obtained in step 112. In step 114, the liquid crystal panel 35 is driven, and the liquid crystal cell corresponding to the pixel whose distance falls within the range of (Da ± Δd) is set to the transmissive state, and the other liquid crystal cells are set to the non-transmissive state. As a result, as shown in FIG. 11, the subject SS in the range of (Da ± Δd) is substantially in focus, and is clearly observed by the finder 33, but other parts (hatched lines are shown). The attached part) becomes unclear. Therefore, the photographer can identify the subject SS that is the subject of focus adjustment and exposure control.
[0041]
In step 115, it is determined whether or not the release switch 15 has been fully pressed. When the release switch 15 is not fully pressed, step 116 is executed to determine whether or not the manual selection switch 18 is set to the on state. The manual selection switch 18 is a switch for manually selecting a subject to be focused. When the manual selection switch 18 is in the OFF state, steps 115 and 116 are repeatedly executed. If the release switch 15 is fully pressed during this time, the photographing operation is executed in steps 121 to 123. If the manual selection switch 18 is set to the on state, the process proceeds to step 117, and the subject whose focus is adjusted is changed. The
[0042]
In step 117, the parameter n is incremented by one. In step 118, it is determined whether or not the parameter n is 5 or less. That is, the distance Dn having the nth largest peak value is set as the significant distance Da. Then, the process returns to step 111, and the operation described above with respect to the significant distance Da is executed. On the other hand, when it is determined in step 118 that the parameter n exceeds 5, the parameter n is set to 0 in step 119 and the process returns to step 117. That is, in this embodiment, the parameter n can be set in the range of 1 to 5.
[0043]
On the other hand, in step 121, the aperture 25 is reduced from the fully open state to the opening corresponding to the exposure condition, and the first mirror 31 and the second mirror 32 are set in the horizontal state. In step 121, the shutter 41 is opened. Thereby, the film 42 is exposed. In step 122, it is determined whether or not the exposure time (shutter speed) determined in step 112 has elapsed. When the exposure time has elapsed, step 123 is executed. That is, the shutter 41 is closed, the first mirror 31 and the second mirror 32 are each set in an inclined state, and the diaphragm 25 is returned to the fully opened state. This terminates this program.
[0044]
As described above, according to the present embodiment, a subject to be focused can be selected from a plurality of objects included in one screen by a simple operation without performing an operation such as a focus lock. It is possible to accurately select a subject to be subjected to focus adjustment or exposure control.
[0045]
FIG. 12 is a block diagram illustrating a circuit configuration of a digital camera including the subject selection device according to the second embodiment. The basic configuration is the same as that of the first embodiment shown in FIG. 2, and a different configuration will be described.
[0046]
The CCD 38 is disposed behind the photographic lens 11 and directly faces the photographic lens 11, and no mirror and shutter are provided as in the first embodiment. In addition to the three-dimensional information memory 48, an image memory 71 and an LCD drive circuit 72 are connected to the imaging signal processing circuit 47, and a liquid crystal monitor 73 is connected to the LCD drive circuit 72. The three-dimensional information memory 48 stores information on the distance to the subject, while the image memory 71 stores image data obtained by the photographing operation. On the other hand, the liquid crystal monitor 73 is controlled by the LCD drive circuit 72 and can display a moving image obtained by the CCD 38. That is, the liquid crystal monitor 73 functions as a finder. Further, a still image can be displayed on the liquid crystal monitor 73 according to the image data stored in the image memory 71.
[0047]
A memory card controller 74 is connected to the system control circuit 51, and a memory card 75 can be attached to the memory card controller 74. The image data stored in the image memory 71 is transferred to the memory card 75 and recorded.
[0048]
Other configurations are the same as those of the first embodiment.
[0049]
FIG. 13 and FIG. 14 are flowcharts of a program for selecting a subject and taking a picture in the memory card 75 in the second embodiment.
The processing contents of steps 201 to 208 are the same as those of steps 101 to 108 shown in FIG. That is, the significant distance Da, which is the distance to the subject to be actually photographed, is obtained based on the histogram relating to the three-dimensional information of a plurality of subjects included in one screen.
[0050]
In step 211, automatic focus adjustment is performed on the subject to be photographed, the photographing lens 11 is driven and displaced in the optical axis direction, and the focal point is adjusted to the significant distance Da. In step 212, the CCD 38 is driven, and the luminance value of each pixel is detected using a photodiode corresponding to the significant distance Da. Then, photometry is performed by integrating these luminance values, and the exposure conditions of the aperture and shutter speed at the time of photographing are obtained. In step 212, image data obtained from all the photodiodes is stored in the image memory 71.
[0051]
In step 213, the depth of field Δd is obtained from the exposure condition (that is, the aperture) obtained in step 212. In step 214, the liquid crystal monitor 73 is driven and the area whose distance is within the range of (Da ± Δd) is displayed in the normal state, but the image data is shifted by 1 bit for the other areas. Thus, the image is displayed darkly. As a result, the photographer can recognize the subject that is subject to focus adjustment and exposure control.
[0052]
The processing contents of steps 215 to 220 are the same as those of steps 115 to 120 shown in FIG. That is, by operating the manual selection switch 18, it is possible to manually select the subject to be focused, and when it is detected in step 215 that the release switch 15 is fully pressed, the process proceeds to step 221. move on. That is, the aperture 25 is reduced from the fully open state to the opening corresponding to the exposure condition, and the CCD 38 is driven to perform exposure for a time corresponding to the shutter speed obtained in step 212. The image data thus obtained is temporarily stored in the image memory 71, read out from the image memory 71 in step 222, and recorded on the memory card 75. This terminates this program.
[0053]
As described above, the second embodiment is an example in which the present invention is applied to a digital camera, and an effect similar to that of the first embodiment applied to a silver salt camera can be obtained.
[0054]
【The invention's effect】
As described above, according to the present invention, an operation for selecting a subject to be photographed from a plurality of objects included in one screen is simplified, and control such as focus lock or backlight correction for the subject is simplified. Is done.
[Brief description of the drawings]
FIG. 1 is a perspective view of a camera including a subject selection device according to a first embodiment of the present invention.
2 is a block diagram showing a circuit configuration of the camera shown in FIG. 1. FIG.
FIG. 3 is a diagram for explaining the principle of distance measurement using distance measurement light;
FIG. 4 is a diagram illustrating distance distribution light, reflected light, gate pulse, and light quantity distribution received by a CCD.
FIG. 5 is a diagram illustrating an arrangement of photodiodes and vertical transfer units provided in a CCD.
FIG. 6 is a cross-sectional view showing a CCD cut along a plane perpendicular to the substrate.
FIG. 7 is a timing chart of a three-dimensional information detection operation for detecting data related to a distance to a subject.
FIG. 8 is a first half of a flowchart of a program for selecting one of a plurality of objects as a subject to be photographed and performing automatic focus adjustment and automatic exposure control on the subject.
9 is the second half of the flowchart of the program shown in FIG.
FIG. 10 is an example of a histogram relating to distance.
FIG. 11 is a block diagram illustrating an example of a screen observed by a finder.
FIG. 12 is a block diagram illustrating a circuit configuration of a digital camera including a subject selection device according to a second embodiment.
FIG. 13 is a first half of a flowchart of a program for performing automatic focus adjustment and automatic exposure control by selecting one of a plurality of subjects in the second embodiment.
14 is the latter half of the flowchart of the program shown in FIG.
[Explanation of symbols]
14 Light emitting device (light source)
38 Image sensor

Claims (10)

A light source that emits ranging light to all objects included in the shooting screen ;
Receiving a reflected light from the pre-Symbol Target product, a number of a photoelectric conversion element, capable of detecting the same image as the image photographed image sensor charge corresponding to the amount of light received is accumulated,
By integrating the signal charges in the photoelectric conversion element, a three-dimensional-information detecting means for detecting three-dimensional information is the distance to each point on the surface of the pre-Symbol Target object from the camera,
A histogram of the distance, on the basis of the histogram, and a subject selection means for selecting an object to be photographed from the front Symbol Target material,
The three-dimensional information detecting means
A signal charge holding portion provided adjacent to the photoelectric conversion element;
The accumulated charge sweeping means for starting the accumulation operation of the signal charge in the photoelectric conversion element by sweeping unnecessary charge accumulated in the photoelectric conversion element from the photoelectric conversion element and stopping its operation,
Signal charge transfer means for transferring the signal charge accumulated in the photoelectric conversion element to the signal charge holding unit;
Bei give a signal charge integrating means for integrating the signal charges in the signal charge storage part by driving said signal charge transfer means and the accumulated charge sweeping means alternately,
A charge sweep signal output by the accumulated charge sweeping means for sweeping out the unnecessary charge and a charge transfer signal output by the signal charge transfer means for transferring the signal charge are pulse signals, respectively. ,
A pulse-shaped ranging light having a predetermined pulse width is output by the light source, and the ranging light pulse is output during a charge accumulation period from the output of the charge sweep signal to the output of the charge transfer signal. Is output, the signal charge corresponding to the three-dimensional information is integrated in the signal charge holding unit .   2. The camera subject selection apparatus according to claim 1, wherein the photoelectric conversion element is of a charge storage type.   2. The camera subject selection apparatus according to claim 1, wherein the photoelectric conversion element is formed along a substrate, and the accumulated charge sweeping unit sweeps unnecessary charges toward the substrate.   2. The camera subject selection apparatus according to claim 1, wherein the signal charge holding unit is a vertical transfer unit for outputting the signal charge to the outside of the three-dimensional image detection unit.   2. The camera subject selection device according to claim 1, wherein the photoelectric conversion element and the signal charge holding unit are configured as an interline CCD having a vertical overflow drain structure.   2. The camera subject selection apparatus according to claim 1, wherein the subject selection unit selects a subject to be photographed based on a maximum peak value of the histogram.   The camera subject selection apparatus according to claim 1, wherein the subject selection unit selects a subject to be photographed based on a ratio of a plurality of peak values included in the histogram.   The camera subject selection device according to claim 1, wherein the subject selection unit selects an object corresponding to one of a plurality of peak values included in the histogram as a subject to be photographed.   The camera subject selection apparatus according to claim 1, further comprising an automatic focus adjustment unit configured to perform automatic focus adjustment on the subject to be photographed.   2. The camera subject selection apparatus according to claim 1, further comprising automatic exposure control means for performing automatic exposure control on the subject to be photographed.

Images