JP4281199B2 - Electronic camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, ShootingUsing image elementsUseRuElectricRegarding child camerasThe
[0002]
[Prior art]
Conventionally, when photographing a subject, it has been necessary to know the distance to the subject, the luminance of the subject, the color temperature of the subject, and the like. For this reason, in general, in addition to the image sensor for photographing, AF (ranging to the subject and automatically driving the photographing lens based on the subject), AE (determining the subject brightness, and exposure conditions (shutter speed and aperture value) based on it ) (Refers to detecting the color temperature of the subject or light source and performing the optimum color reproduction of the subject, which is called AWB when automatically controlling this), etc. Elements were used, and in some cases, a dedicated optical system was required.
[0003]
For example, in AF, a dedicated optical system is provided so that an AF sensor is arranged at a position equivalent to the film surface, and in addition to this dedicated AF element, in order to perform calculation with an optimum light amount, it is separate from the image sensor. It was necessary to provide an element for monitoring the amount of incident light. The same applies to AE, and a dedicated optical system and a dedicated sensor composed of a plurality of photometric areas are necessary to improve photometric accuracy.
[0004]
In addition, unlike an ordinary video camera, an electronic still camera needs to capture subject information under optimum conditions as soon as possible after the shutter release so as not to miss the targeted shutter chance. In order to make the shutter time lag as short as possible, a separate white balance (WB) dedicated sensor is usually required so that the color temperature at the time of shooting can be detected before shooting and an optimum white balance can be shot. .
[0005]
On the other hand, various forms have been devised and announced for the idea of performing AF, AE, and AWB all or a part thereof using an imaging sensor. An example of a device for performing all the functions described above with an imaging sensor is disclosed in Japanese Patent Application Laid-Open No. Hei 2-210974.
In this case, a CCD image sensor is used, and AWB, AF, and AE are performed in this order, and the last image is taken. The outline will be described below. First, in order to accurately perform various calculations within the CCD dynamic range, the CCD overflow time at the subject brightness is first measured. In the subsequent measurement of the color temperature, a diffusion plate is inserted into the optical system, the exposure is performed after uniformizing the amount of light on the imaging surface, and the output signal from this imaging device is passed through a color separation circuit and an integrator, and A / D Convert and import to CPU to perform AWB calculation.
[0006]
In the subsequent AF calculation, first, a focusing lens and a phase difference detection optical system are inserted into the optical system, and after the CCD is reset, exposure is performed for the overflow time. Of the output from the CCD, only the AF area is selected by an external switch, A / D converted and taken into the CPU for AF calculation. Regarding the AF method using this phase difference method, for example, Japanese Patent Laid-Open No. 9-184974 discloses a principle and a method using time-series pupil division as a method for realizing the principle.
[0007]
Next, in the subsequent AE calculation, after the optical system used in the AF metering described above is retracted and exposed by the CCD, only an area corresponding to spot metering and average metering is extracted and integrated by an external switch, and A / D This is converted and AE calculation is performed by the CPU.
On the other hand, CMOS image sensors are used in the manufacturing process of the image sensor to reduce costs and power consumption, and various types of CMOS image sensors with signal processing or calculation functions inside the sensor chip have been announced. In recent years, products that apply these to actually cheap electronic cameras have been announced.
[0008]
The CMOS sensor is characterized in that a minute signal photoelectrically converted by a photodiode is read after being amplified by a cell amplifier formed for each pixel. Until now, SIT (Static Induction Transistor), CMD (Charge Modulation Device), Various types such as BASIS (BAse Stored Image Sensor), FGA (Floating Gate Array), BCMD (Bulk Charge Modulated Device), AMI (Amplified MOS intelligent Imager), BCAST (Buried Charge Accumulator and Sensing Transistor Array) have been announced. . For details of these sensors, various documents have been published. Please refer to them.
[0009]
Recently, in addition to these, a vision chip, a sensor that integrates arithmetic functions into an image sensor and performs parallel 3D image processing, and an artificial retina sensor that can perform simple retinal functions have been announced. The application of this artificial retina chip to games, mobile phones, security systems, etc. has also been announced.
Regarding the artificial retina chip, the detailed contents of the principle and function are described in JP-A-6-139361, JP-A-8-292998, etc., so please refer to them.
[0010]
Here, the main functions realized by the artificial retina chip described there will be described next. First, by sending a signal to a plurality of scanners that control reading of each light receiving element (sensor) for each column, it is possible to output from any row to any row. The result of product-sum operation of the voltages supplied to the plurality of scanners and the input image intensity is obtained as the output of the sensor. This makes it possible to easily obtain an image output obtained by calculating between pixels (such as contour enhancement).
[0011]
Further, pattern matching is possible by sequentially applying the scanner control signal as a desired pattern. Furthermore, by installing a random scanner that controls the column direction of the sensor, it is possible to read out an arbitrary range in the column direction. As a result, only the image in an arbitrary area is read out together with the above-described arbitrary row reading function. Is possible. Even when there are a plurality of gaze patterns, a plurality of read areas may be set and the areas may be read in order.
[0012]
By adding a circuit for setting the time from resetting the sensor cell to reading out the partial image according to the brightness of the portion, the accumulation time can be changed for each cell or for each of a plurality of regions. By reading out after transferring two or more lines at the time of reading, it is possible to reduce the resolution and to perform pattern matching at high speed.
[0013]
In addition, it is possible to give this element various functions, such as a spatial direct conversion of images and a character recognition function.
In general, since the CCD type image pickup device transfers and outputs the charge itself stored in accordance with the amount of received light to the photoelectric conversion unit, once the signal is read, no signal charge remains in the light receiving cell. In contrast to (destructive devices), most of the CMOS sensors described above amplify the charge accumulated in the photoelectric conversion unit by using the above-mentioned cell amplifier using a MOS type FET or the like, convert it into a voltage and output it. Therefore, there is a significant feature that no signal charge is consumed at the time of reading, and signals can be repeatedly read even during light reception (non-destructive element).
[0014]
[Problems to be solved by the invention]
However, in the above-described method of performing AE, AF, and AWB with the image pickup device alone, it is necessary to set an optical system suitable for each measurement purpose before each measurement. For this reason, even if the photographer wants to photograph the subject and presses the shutter, it takes a very long time to actually start imaging and misses an important shutter opportunity.
[0015]
  The present inventionIsElectricity with less imlagChildThe purpose is to provide mela.
[0016]
[Means for solving problems]
The electronic camera according to claim 1 includes an imaging surface including a plurality of light receiving elements that receive subject light and accumulate electric charges, and the order and timing of outputting signals from the respective light receiving elements can be arbitrarily set. And an imaging element that adds and outputs at least two light receiving element signals of the plurality of light receiving elements, a designation unit that designates a first range and a second range of the imaging surface of the imaging element, After the charge accumulation of each of the plurality of light receiving elements is reset, the charge accumulation is started. After the charge accumulation is started, the charge accumulation is not reset, and every predetermined number within the first range designated by the designation unit. Reading means for reading the addition signal obtained by adding the light receiving element signals every predetermined time, and each time the reading means reads the addition signal, the level of the addition signal is in a predetermined level range. Determining means for determining whether or not the light receiving element is in charge, and measuring means for measuring the accumulation time from the reset of charge accumulation of the light receiving element to the start of charge accumulation until the level of the addition signal falls within a predetermined level range And when the determination means determines that it is within a predetermined level range, the photometric calculation for calculating the photographing condition based on the accumulation time is started, and a plurality of values within the second range specified by the specification means Control means for starting distance measurement calculation for calculating the distance to the subject based on the signal of the light receiving element, driving the photographing lens according to the result of the distance measurement calculation, and performing color measurement calculation for calculating the color temperature of the object; It is characterized by providing.
[0022]
  Claim1InventionAccording toThe driving lens is driven based on the distance calculation result.Take insideIs it an image element?FaithIs used, and the color temperature of the subject is calculated based on this, thereby minimizing wasted time.. SoAs a result, one imaging sequence can be shortened.
[0050]
  Figure7 shows a Bayer array that is most commonly employed as a filter of an image pickup element for reasons such as good color reproduction. The opening filter will be specifically described with reference to FIG. 7 and FIG.
[0051]
  In this case, a G filter is provided in one opening (606a and 607a in FIG. 6), and a magenta filter that is a complementary color of R and B is provided in the other opening (606b and 607b in FIG. 6). The transmitted light beam forms an image on the R and B light receiving elements on the image sensor, while the light beam transmitted through the G filter forms an image on the G light receiving element. Since the separated G screen and magenta screen have the same resolution, these two types of screens are used as the basis.ZhouRanging calculation can be easily performed using intelligent correlation calculation.
[0063]
DETAILED DESCRIPTION OF THE INVENTION
Next, a preferred embodiment according to the present invention will be described. FIG. 1 shows an embodiment of an electronic camera according to the present invention.
In FIG. 1, 101 is a photographing lens for capturing a subject image, 102 is provided with various apertures shown in FIG. 6, and is a stop for limiting the light beam incident on the image sensor, and 103 has a random reading and adding function. As an image pickup device, an artificial retina chip or the like whose main functions are shown in paragraphs 0011 to 0013 is used. Further, the image sensor 103 has a filter array as shown in FIG. 7, and a light beam from a subject passing through the diaphragm 102 is imaged on the image sensor 103, converted into an electric signal and output. An embodiment of the diaphragm 102 will be described with reference to FIG.
[0064]
In FIG. 6, a plurality of selectable apertures (602 to 605) having different sizes according to the amount of incident light are provided on a diaphragm 601 that shields a light beam, and apertures are provided at symmetrical positions in the vertical and horizontal directions with respect to the optical axis. The apertures (606a, 606b and 607a, 607b) for dividing the incident light flux (pupil division) and performing AF control are arranged. The pupil division AF openings 606a, 606b, 607a, and 607b are respectively provided with the same or complementary color filters as the filters of the image sensor 103. In the case of the image sensor of the filter arrangement of FIG. 7, it is preferable to install a G (green) filter in the openings 606a and 607a and an M (magenta) filter which is a complementary color of G in 606b and 607b.
[0065]
The subject signal converted into an electrical signal by the image sensor 103 is subjected to CDS processing, gamma processing, etc. in the next signal processing circuit 104 and then converted into a digital signal, and further known gain adjustment, interpolation, compression, etc. Are recorded on a removable recording medium 105 such as a memory card.
In addition to the known signal processing, the signal processing circuit 104 calculates a shutter time and an aperture value from a signal based on the photometric exposure, and performs white balance on the photographed image from the signal based on the colorimetric exposure. Circuit for applying, circuit for determining whether or not the contrast at the time of pupil division AF is sufficient, circuit for separating the light flux that has passed through the two pupils into two image signals by sampling, and the two separated images And a circuit for calculating the amount of focus deviation by performing a correlation calculation between the two. These circuits can be constituted by one ASIC, and as a result, the camera can be further downsized.
[0066]
The display device 106 is used to display a moving image of a subject when the camera is performing video operation. Thereby, it is possible to confirm the exposure condition, the focusing accuracy, the angle of view, and the like in advance when photographing. Of course, an image signal recorded on the recording medium 105 can be reproduced, converted into a signal form suitable for display by the signal processing circuit 104, and displayed on the display device 106.
[0067]
The control circuit 107 is a circuit that controls the entire camera sequence, and includes a shutter button (not shown) operated by the user, an AE mode selection button for selecting spot metering, center-weighted metering, an AE / AF area selection button, and the like. In response to an input from the operation member 108, a series of photographing and recording operations are started. The control circuit 107 outputs a signal to the driver 109 based on the various signal processing results in the signal processing circuit 104 described above, and rotates the diaphragm 102 to set the optimum diaphragm opening.
[0068]
When the aperture is rotated, if it is during photographing, an aperture for aperture (602 to 605) is selected. If the AE and AF operations are being performed, any of the pupil division AF apertures (606, 607) is selected. Select. Further, the control circuit 107 outputs a signal to the driver 110 based on the correlation calculation result described above, and moves the lens to the in-focus position. When the lens is not focused as a result of this lens movement, or when it is determined that AF is impossible due to insufficient contrast, the control circuit 107 may include switching means for enabling manual driving of the lens.
[0069]
FIG. 2A is a flowchart for explaining operations related to photographing of the electronic camera of the present invention. In FIG. 2A, after the power is turned on, the above-mentioned various operation members (108) select the center weight, the photometry mode such as spot photometry, the position of the photometry area, the position of the distance measurement area, etc. in step S201. Immediately, the photometric operation is started in step S202. The photometry position and the distance measurement position are initially set at the central portion where important subjects often come unless particularly selected.
[0070]
As soon as a predetermined signal level is obtained from the photometric area set on the image sensor by this photometric operation, photometric calculation for calculating the shutter speed and aperture value for photographing is started. At the same time, in the next step S203, the distance measurement to the subject is started using the signal from the same distance measurement area as the above-mentioned light measurement area already selected in step S201. Details of the contents of the distance measurement will be described later.
[0071]
If the result of step S203 is that the subject is in focus, the subject is immediately photographed in the next step S204. However, shutter release is possible only after both the steps of distance measurement and photometry calculation are completed. If a signal from the light receiving element is output in step S204, an operation for colorimetry is immediately started in the next step S205. Using the result of the colorimetric calculation, the subject is subjected to white balance by a known method such as setting the color difference signal to zero, and then subjected to processing such as gamma adjustment and compression before recording on the recording medium 105. Note that while the shutter is half-pressed, the above-described photometry in step S202 and the distance measurement in S203 are repeated.
[0072]
As described above, in this method, each operation of photometry, distance measurement, and colorimetry is continuously performed. That is, when a light reception output as a result of a certain operation is obtained, a predetermined calculation is immediately started based on the output, and at the same time, the next operation is started. Furthermore, since the colorimetric operation is performed after the actual exposure for photographing, the time lag until photographing can be minimized.
[0073]
When the non-destructive element described above is used as the imaging element, an imaging sequence as shown in the flowcharts of FIGS. 2B and 2C is also possible. That is, in the case of FIG. 2C, if the optimum output is obtained from the image sensor as a result of the photometric operation, the photometry calculation is started and the colorimetric output signal is immediately taken out from the image sensor in the almost same exposure state. Since the color calculation is started and the distance measurement signal is taken out from the selected area and the distance measurement is started, the time lag until the next photographing can be extremely shortened.
In the case of FIG. 2B, since the colorimetric calculation is performed using the signal received in the distance measurement operation as it is after the photometry and distance measurement operation, the time lag until photographing can be extremely shortened in this case as well. . Of course, the colorimetric operation and calculation described so far can be set manually, and in that case, the steps for colorimetry can be omitted from the sequence described so far. The cycle can be further shortened.
[0074]
  ThisOf course, the colorimetric operation and calculation described so far can also be set manually. In that case, the steps for colorimetry can be omitted from the sequence described so far. The cycle can be further shortened.
[0075]
Next, the photometry area and the distance measurement area will be described with reference to FIG. FIG. 3A shows an example of the display of the finder 301, and five small squares 302 are areas for spot metering and distance measurement. By operating the AE / AF area selection button 108 in FIG. Of these five areas, one area is selected. Usually, the spot photometry area and the distance measurement area are operated so as to coincide with each other.
[0076]
By operating the AE / AF area selection button 108 in FIG. 1 described above, it is possible to measure different areas for the spot photometry area and the distance measurement area. Next, the structure of one area 302 of the five areas in FIG. 3A and the center emphasis area 303 in FIG. 3A will be described. Here, the structures of these areas differ depending on the type of image sensor used in the electronic camera.
[0077]
Here, the photometric flowchart of FIG. First, in FIG. 4, in step S401, the aperture for photometry (any of 602 to 607 in FIG. 6) and the time interval of signal readout from the image sensor (t1, t2, t3,... In FIG. 3D). ) Is set. In order to minimize the time lag from the shutter release to photographing, it is desirable to use one of two apertures 606 or 607 for use in distance measurement, which will be described later.
[0078]
In the next step S402, the image sensor is reset and exposure is started. In step S403, the photometric areas on the image sensor (302 and 303 in FIG. 3) are set at the time intervals (t1, t2, t3,...) Set earlier. ) Is read out. At this time, as described above, if the image pickup device is a non-destructive type image pickup device that adds and outputs the signals of the light receiving elements, the five areas of FIG. A signal added at each time interval is continuously read out from one area or the central emphasis area 303, and it is determined whether or not the output level is within a preset level range.
[0079]
For example, in the range of this level, in the case of low luminance, the SN is obtained so that an error in photometric calculation does not occur. In the case of high luminance, the image sensor output is not saturated. Set to range. Then, as shown in FIG. 3 (d), reading is performed in the order of t1, t2, t3,..., In ascending order of time, and immediately after entering the predetermined range in step S404, the shooting shutter time and aperture are set in step S405. The calculation for determining is started.
[0080]
At the same time, the process proceeds to step S406 for distance measurement calculation (to be described later) for reading a signal from one distance measurement area 302 in FIG. Next, the case where it is outside the predetermined range in step S404 will be described. First, the reading time intervals are t1, t2,..., T10, and each time is set to a power of 2 such as 1/248, 1/1024,. If the subject brightness is too bright and the output level after t1 time has already reached the saturation output of the image sensor, the aperture value is set to the minimum aperture (605) in FIG. 6 or the shutter time is set to the image sensor. By setting the shutter speed as high as possible or using them together, it is possible to cope with the high luminance side.
[0081]
Here, the shutter time is set to be one time interval corresponding to the power of 2 from t1. On the other hand, if the subject brightness is too dark and the output level does not reach the appropriate range even after t10 hours, the setting opposite to that described above may be performed. In this manner, first, in step S407, it is confirmed whether or not the aperture or shutter has already been changed. If it has not been changed, a predetermined change is made in step S408, and then a new reset is made in step S402. Start exposure.
[0082]
If the aperture and shutter have already been changed in step S407, an over or under warning is given in the next step S409, and in step S410, as many values as possible for shooting are set, although not optimal settings. Then, the process proceeds to the next shooting step S406. In addition, if it is known from the beginning that it is brighter or darker than usual when shooting at night or outdoors at a ski resort, the time required for photometry can be shortened by shifting the above-mentioned time interval in advance. I can do it.
[0083]
On the other hand, the case where the image sensor is a destructive element will be described below. FIG. 3B shows an enlarged view of one of the five areas shown in FIG. Here, for the sake of simplicity, the area is divided into five equal parts in the vertical and horizontal directions and divided into a total of 25 areas. The numbers in the areas are the four types of read time intervals t1, t2, t3 shown in FIG. , T4 is shown. Each divided block is further composed of, for example, a block of 2 × 2 pixels or more. The pixels in the same block and the blocks set at the same time interval are simultaneously added and output.
[0084]
In this way, the average signal level of a plurality of pixels in the area can be obtained in the order of shorter readout time, and the signal accumulation state can be monitored in real time even for destructive elements. One block described here may be composed of a single pixel.
In FIG. 3C, the selected area is divided into three areas, the upper and lower two areas are used for photometry, and the middle area is used for distance measurement. With this configuration, if the average signal output from the upper and lower photometry blocks falls within the proper range, photometry calculation starts immediately, and at the same time, signals from individual light receiving pixels are read out from the center distance measurement area. Thus, the distance measurement calculation can be started, and it is not necessary to reset the image sensor for the distance measurement exposure after the photometry exposure, so that no time is lost.
[0085]
Next, a flowchart for distance measurement will be described with reference to FIG. First, regarding the exposure in step S501, if a non-destructive image sensor is used as the image sensor, the charge state accumulated by the exposure at the time of photometry is used as it is, and if a destructive element is used. However, if it is the case of the selection area structure described in FIG. 3C, there is no need to newly reset and perform exposure. Signals are individually read out from the AF area selected in the next step S502. If the subject luminance is low at this time, the contrast is increased by electrically increasing the gain and increasing the signal level. Just go to the next step.
[0086]
In addition to the method of increasing the gain, the output signal level can be increased by outputting after adding two adjacent pixels. In addition to the method of simply adding the first and second pixels and outputting them, and then adding and outputting the third and fourth pixels, the first and second pixels are added. And the second pixel and the third pixel are added, and then the second pixel and the third pixel are added, followed by shifting one pixel at a time in order, and then output. Can be suppressed. Of course, not only the addition of two pixels but also more pixels may be added.
[0087]
  In this way, subject brightnessInAccordingly, it is determined in step S503 whether or not the signal level read by the optimum reading method is a level suitable for AF calculation. This step is usually not necessary when the AF signal is taken out immediately after metering, but the subject brightness may change while the lens is moving during the in-focus state described later. In such a case, since it is necessary to perform photometry again, the process proceeds to step S504.
[0088]
If it is confirmed in step S503 that the level is appropriate, AF calculation is performed in the manner described above in step S505. As a result, if it is determined in the next step S506 that the in-focus state is obtained, the process proceeds to the next step S507, and the process proceeds to the step for original photographing or colorimetry in the photographing procedure described above. If it is determined in step S506 that the subject is not in focus, the lens movement amount is calculated based on the amount of deviation calculated in step S506, and this amount exceeds the infinity or closeness of the lens in the next step S508. Check if it exists.
[0089]
If it is within the movable range of the lens, after moving the lens in the next step 509, the image sensor is reset in step S510, and the process of returning to step S501 and performing the AF calculation again is repeated. If it is finally determined in step S506 that the lens is in focus, the process proceeds to the next step S507. If the lens is moved several times, the lens does not focus, or if the lens is infinite or close, AF is performed in step S511. The display is disabled and the process proceeds to step S507 for the next operation.
[0090]
However, in this explanation, although it is not focused in this way, the procedure proceeds to the next procedure and it is possible to shoot, but this is of course the photographer's preference, and if it is not focused, shooting It may be set so that it cannot.
When the steps for ranging are completed by the above procedure, the image sensor is immediately reset, and the subject is photographed using the shutter speed and aperture value obtained from the result of the above-mentioned photometric calculation. The image signal read from the image sensor during this shooting is normally read out on the full screen, but if you want to increase the number of recorded images on the recording medium or shorten the cycle time until recording, the signal thinned out from the image sensor is used. Reading is also possible.
[0091]
The read signal is first recorded in a buffer memory for one screen converted into a digital signal, then subjected to processing such as gamma processing, white balance processing, and compression, and finally recorded as a still image on the recording medium 105. The Here, as soon as it is recorded in the buffer memory, a signal obtained by adding the light reception signals for the respective color filters is immediately read from the image sensor, and the color difference signal is set to zero based on the magnitude of each color signal. Perform white balance processing.
[0092]
Until now, for example, various processes and operations have been performed based on the vertical synchronization signal according to the above-described shooting procedure, but in the present invention, since one operation is completed and the next operation is performed at the same time, no time is wasted. In addition, since reading is performed after performing as much processing as possible in the image sensor, external processing is reduced in both hardware and software, and thus the shutter time lag can be extremely shortened.
[0093]
Further, in the present invention, it has been described that all of photometry, colorimetry, and distance measurement are performed using a single image sensor. However, of course, it is not necessary to forcibly give all functions to a single element. In order to achieve the most efficient form, the functions described so far may be achieved by appropriately combining with each dedicated element.
[Brief description of the drawings]
FIG. 1 is a block diagram of an embodiment of an electronic camera according to the present invention.
FIG. 2 is a flowchart showing operations up to photographing of the electronic camera of the invention of FIG. 1;
3 is a diagram showing display in the viewfinder, details of photometry and distance measurement area of the electronic camera of the invention of FIG. 1, and timing when a signal is read out from an image sensor during photometry.
4 is a flowchart at the time of photometry of the electronic camera of the invention of FIG. 1; FIG.
5 is a flowchart at the time of distance measurement of the electronic camera of the invention of FIG. 1. FIG.
6 is a view showing an embodiment of an aperture used in the electronic camera of the invention of FIG. 1. FIG.
7 is a diagram showing an example of a filter array of an image sensor used in the electronic camera of the invention of FIG. 1. FIG.
[Explanation of symbols]
101 Shooting lens
102 Aperture
103 Image sensor
104 Signal processing circuit
105 Recording medium
106 Display device
107 Control circuit
108 Operation member
109, 110 drivers
301 Finder,
302 Spot metering / ranging area
303 Central priority area
601 Aperture
602, 603, 604, 605 Aperture aperture
606a, 606b, 607a, 607b AF aperture

Claims (9)

An imaging surface comprising a plurality of light receiving elements for receiving subject light and accumulating charges is provided, and the order and timing of outputting signals from each of the light receiving elements can be arbitrarily set. An image sensor that adds and outputs at least two light receiving element signals;
Designation means for designating a first range and a second range of the imaging surface of the imaging element;
Charge accumulation starts after resetting the charge accumulation of each of the plurality of light receiving elements, and after the charge accumulation starts, the light receiving element signals for each predetermined number within the first range are added without resetting the charge accumulation. Reading means for reading out the added signal every predetermined time;
Determination means for determining whether the level of the addition signal is within a predetermined level range each time the reading means reads the addition signal;
Measuring means for measuring an accumulation time from the reset of charge accumulation of the light receiving element to the start of charge accumulation until the level of the addition signal falls within a predetermined level range;
When the determination means determines that the image is within a predetermined level range, the photometric calculation for calculating the photographing condition is started based on the accumulation time, and the subject is determined based on signals from a plurality of light receiving elements within the second range. An electronic camera comprising: a control means for starting a distance measurement calculation for calculating a distance up to and driving a photographing lens based on a result of the distance measurement calculation and calculating a color temperature of a subject. . The electronic camera according to claim 1,
It further includes a shooting instruction means for instructing shooting,
When the photographing instruction is given by the photographing instruction unit, the control unit resets the image sensor and outputs a light receiving element signal imaged under a photographing condition based on a result of the photometry calculation, and based on the light receiving element signal, the measurement unit outputs the light receiving element signal. An electronic camera characterized by color computation. The electronic camera according to claim 2,
The image pickup device outputs the light receiving device signal after thinning out the signal. The electronic camera according to any one of claims 1 to 3,
The image sensor includes a color filter including at least a first color and a second color different from the first color in each light receiving element,
The control means is based on the addition signal obtained by adding only the signals of the light receiving elements including the first color filter and the addition signal obtained by adding only the signals of the light receiving elements including the second color filter. An electronic camera characterized by performing colorimetric calculation. The electronic camera according to any one of claims 1 to 4,
The reading means reads an addition signal added for each of the first block and the second block different from the first block from the plurality of light receiving elements within the first range, and when the first predetermined time elapses, An electronic camera that reads an addition signal and reads the addition signal of the second block when a second predetermined time longer than the first predetermined time elapses. The electronic camera according to any one of claims 1 to 5,
As a result of the distance calculation, further comprising a focus determination means for determining whether or not it is in focus,
The control means calculates at least an aperture value as the photographing condition,
The electronic camera according to claim 1, wherein the in-focus determination unit changes a determination criterion for determining whether or not the in-focus state is in accordance with the aperture value. The electronic camera according to any one of claims 1 to 6,
The electronic camera according to claim 1, wherein the specifying unit specifies the first range and the second range as the same range. The electronic camera according to any one of claims 1 to 7,
The electronic camera according to claim 1, wherein the designation means can designate a plurality of ranges independent of each other as the first range. The electronic camera according to any one of claims 1 to 8,
The electronic camera according to claim 1, wherein the reading unit reads an addition signal obtained by adding a light receiving element signal in a central range of the imaging element as the first range.

Images