JP4027074B2 - Electronic camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic camera with interchangeable lenses. thing It is.
[0002]
[Prior art]
Some electronic cameras with interchangeable lenses have different mount diameters for each camera body and interchangeable lens with different image sizes. However, with such cameras, the versatility of interchangeable lenses is poor. . However, if all the mounts are shared, there is no problem for a camera body for a small image size if it is an interchangeable lens with a large image size. However, if the image size of the interchangeable lens is small, vignetting of the light beam (vignetting) Such problems arise.
[0003]
In contrast, for example, as shown in JP-A-2-33267 and JP-A-2-33268, an interchangeable lens having a small image size cannot be mechanically attached to a camera body having a large image size. Occurrence of problems such as vignetting can be prevented. Further, as disclosed in Japanese Patent Laid-Open No. 2-39777, the interchangeable lens and the camera body are electrically connected, and the camera body side is based on information related to the image size of the interchangeable lens stored on the lens side. If it is determined that the image size of the interchangeable lens does not match the image size (when the image size on the interchangeable lens side is small), a configuration may be considered in which a warning is issued.
[0004]
On the other hand, all of the above electronic cameras prevent the occurrence of problems such as vignetting by avoiding the mounting of the interchangeable lens when the image size of the interchangeable lens is not compatible with the camera body. The versatility of the lens is not sufficiently secured.
[0005]
Therefore, for the purpose of providing an electronic camera that can obtain a good shot image without vignetting even when an interchangeable lens having an image size that does not fit the camera body is mounted, the camera body having a camera side mount And an interchangeable lens having a lens-side mount coupled to the camera-side mount, and an input means for inputting information representing an image size of the interchangeable lens to the camera body, and the input means Based on the information, a determination unit that determines whether or not the image size of the interchangeable lens is adapted to the camera body as it is, and an image sensor formed by the interchangeable lens when the determination unit determines that the image size is incompatible The image signal representing the above image is subjected to signal processing by an electronic circuit to thereby obtain the image. The electronic zoom for enlarging an image corresponding to a predetermined range of the image on the element, has also been proposed to adapt the camera to the image size of the interchangeable lens.
[0006]
In addition, as shown in Japanese Utility Model Publication No. 5-66629, a silver halide camera that can switch between a standard screen size and a panoramic screen size provided in the camera, the photometric area of the photometric element is the screen size. Something that has been proposed to meet
[0007]
[Problems to be solved by the invention]
However, the conventional method described above has the following disadvantages.
[0008]
In a camera that changes the imaging size in accordance with the image size of the photographic lens, there is no disclosure that changes the photometric area according to the change of the imaging range.
[0009]
In addition, a camera that can change the shooting range is disclosed in which the photometry area is changed according to the change of the shooting area, but it does not support lenses with different image sizes. There were problems such as shooting and inaccurate exposure.
[0010]
(Object of invention)
An object of the present invention is to provide an electronic camera capable of setting an appropriate photometric area in accordance with image size information of an attached interchangeable lens in an electronic camera capable of attaching an interchangeable lens having a different image size. It is.
[0011]
[Means for Solving the Problems]
To achieve the above objective, The present invention Camera side mount that can be combined with the lens side mount of the interchangeable lens, Divided photometric means for dividing the area into a plurality of areas, and the number of photometric areas used for measuring a photometric value used for controlling the exposure amount among the plurality of photometric areas is the image size information from the interchangeable lens. The photometric area used for the measurement is within the imaging range of the image sensor on the camera body side. This is an electronic camera.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on illustrated embodiments.
[0014]
FIG. 1 is a block diagram showing an internal configuration of an electronic camera (digital camera system) according to an embodiment of the present invention.
[0015]
As shown in FIG. 1, an electronic camera according to an embodiment of the present invention includes a camera body 1, a photographing optical system composed of a plurality of lens groups, driving means for driving the same, and a light beam transmitted through the photographing optical system. The photographic lens unit (hereinafter referred to as a photographic lens) 2 is constituted by a light quantity limiting means for adjusting the amount of incident light, and the photographic lens 2 is detachable from the camera body 1.
[0016]
The camera body 1 includes the following members.
[0017]
Reference numeral 3 denotes a system controller which is a control means for controlling the electric circuit of the entire electronic camera including the camera body 1 and the photographing lens 2 (details will be described later). Is a shutter according to the control from the system controller 3 4 , 6 is a mirror for allowing the photographer to observe the light flux from the photographic lens 2, 7 is a mirror control circuit for controlling the drive of the mirror 6, 8 is a focusing plate, and 9 is in accordance with the imaging size. A transmissive liquid crystal plate for changing the viewfinder field ratio, 10 is a pentaprism, 11 is a photometric mirror composed of a half mirror for directing a part of light emitted from the pentaprism 10 to the photometric system, and 12 is provided on the photometric sensor 13. A photometric lens for forming a subject image, 14 is a photometric circuit for A / D converting the output from the photometric sensor 13 and controls the photometric sensor 13 according to an instruction from the system controller 3, and 15 is a subject image for the photographer. It is an eyepiece that makes it possible to observe.
[0018]
Reference numeral 16 denotes an attitude detection sensor for detecting the attitude of the camera body 1, 17 denotes a distance measuring sensor, 18 denotes a distance measuring circuit for driving the distance measuring sensor 17, and 19 denotes an external light color for adjusting the white balance of the photographed image. A colorimetric sensor for measuring color, 20 a white balance A / D circuit for A / D converting the output of the colorimetric sensor 19, and 21 receiving an output from the white balance A / D circuit 20 to obtain a white balance correction value. This is a white balance control circuit to be sent to the system controller 3.
[0019]
Reference numeral 22 denotes an image sensor that receives a subject image and photoelectrically converts it into an electrical signal to generate an image signal representing a still image. Reference numeral 23 denotes an image signal generated by an electronic imaging means including the image sensor 22. An image pickup circuit that receives a correction value from the white balance control circuit 21 via the system controller 3 and performs white balance correction and other predetermined image processing, and 24 is an image signal (analog signal) output from the image pickup circuit 23. A / D conversion circuit 25 for converting a digital signal into a digital signal, and a memory 25 such as a buffer memory composed of a DRAM or the like for temporarily storing various data such as a digital signal and a white balance correction value.
[0020]
Reference numeral 26 denotes a liquid crystal display device (hereinafter referred to as an LCD) having a function of displaying an image and an image pickup range mark when the image pickup range is determined. Reference numeral 27 denotes an LCD which controls the LCD 26 and is temporarily stored in the memory 25. The digital image signal is received, converted into an analog signal in an optimum form for display as an image, transmitted to the LCD 26, and the transmissive liquid crystal plate 9 is controlled when the imaging range is determined. LCD control circuit for controlling the viewfinder field frame, 28 is a recording medium such as a memory card for recording image signals as image data in a predetermined form, and 29 is a digital image signal temporarily stored in the memory 25. An image processing circuit which is an image processing means for performing predetermined image processing. Reference numeral 30 denotes an output signal from the image processing circuit 29, which is subjected to compression processing and the like so as to be optimal image data for recording on the recording medium 28. 28 This is a compression / decompression circuit that reads out image data that has been compressed and recorded, and performs decompression processing or the like so as to obtain an image signal that can be subjected to various types of image processing.
[0021]
A strobe device 31 is an illuminating unit that irradiates a predetermined auxiliary light beam as necessary when photographing. Reference numeral 32 denotes a connection portion for mounting a connection cable or the like for electrically connecting the camera body 1 and an external device (not shown), and data transfer by controlling a control signal between the camera body 1 and the external device. It is an external interface (I / F) unit that performs the above. Reference numeral 33 denotes a signal generation circuit that receives signals generated in accordance with changes in the state of the following various switches disposed on the exterior of the camera body 1 and outputs predetermined commands to the system controller 3. Reference numeral 34 denotes a release member described later. A switch (SW1) that is turned on by one stroke, 35 is a switch (SW2) that is turned on by the second stroke of the release member, 36 is a zoom switch, 37 is a macro switch, and 38 is an image size discrimination start switch. Reference numeral 39 denotes a driving circuit for controlling various driving means provided in the photographing lens 2, reference numeral 40 denotes a sounding body for issuing a warning, and reference numeral 41 denotes a lens for detecting whether the photographing lens 2 is attached to the camera body 1. The attachment / detachment detection unit 42 is an interface (I / F) unit that performs control so as to receive various types of information regarding the photographing optical system stored in a storage unit provided inside the photographing lens 2.
[0022]
1a and 1b are electrically connected to each other when the camera body 1 and the photographing lens 2 are connected, and an output signal from a storage unit in the photographing lens 2 is input to the camera body 1 side, It is an electrical contact made of a contact member serving as a signal path for outputting a control signal or the like from the system controller 3 to a predetermined member of the photographing lens barrel.
[0023]
On the other hand, the photographing lens 2 includes the following members.
[0024]
43 is a zoom lens that is a variable magnification optical system, and 44 is a stop that is a light amount limiting unit that limits the amount of incident light of a light beam from a subject (hereinafter referred to as a subject light beam) collected by a photographing optical system including the zoom lens 43. , 45 is a focus lens that is a focusing optical system, 46 is a zoom motor that moves the zoom lens 43 in a direction along the optical axis o of the photographing optical system, 47 is a diaphragm actuator that drives the diaphragm unit 43, and 48 is a focus. An AF motor 49 moves the lens 45 in a direction along the optical axis o of the photographing optical system, 49 is prestored with various kinds of information related to the photographing lens 2, such as image circle information and shading correction information. A storage unit such as a ROM.
[0025]
Reference numerals 2a and 2b denote electrical contacts provided at predetermined positions on the rear end surface of the photographing lens 2, and come into contact with the electrical contacts 1a and 1b provided on the front surface on the camera body 1 side. 1 and the photographic lens 2 are electrically connected to output predetermined information from the storage unit 49 of the photographic lens 2 to the camera body 1 side, or to receive a control signal from the system controller 3 of the camera body 1 of Is.
[0026]
As described above, the camera body 1 and the photographing lens 2 constituting the electronic camera are configured separately from each other, but the photographing lens 2 can be mechanically attached to the camera body 1. It has become.
[0027]
When the camera body 1 and the photographic lens 2 are mechanically connected, the electrical contacts 1a and 1b and the electrical contacts 2a and 2b provided on the camera body 1 and the photographing lens 2 are brought into contact with each other. Connection is established.
[0028]
As shown in FIG. 2 to be described later, a photographic lens mounting detection pin 50 is provided on a part of the front surface of the camera side mount 51. When the photographic lens 2 is mounted, the mounting detection pin 50 is pushed. The lens attachment / detachment detection unit 41 transmits a mounting confirmation signal to a system controller in the camera body.
[0029]
In this connected state, in addition to various electrical circuits inside the camera body 1, various electrical circuits inside the photographing lens 2 are also electrically connected, and the system controller 3 is connected to a lens system (not shown). Together with the controller, it serves as a control means for controlling the entire electronic camera.
[0030]
As the recording medium 28 for recording the image signal in the camera body 1 and various image information associated therewith as an image data file, for example, a semiconductor memory that is detachably disposed and has a card shape, a stick shape, or the like. Etc., a magnetic recording medium such as a floppy (registered trademark) disk, a small hard disk, a magnetic tape, a magneto-optical recording medium such as an MO (Magneto-Optical) disk, an MD (Mini Disk), and the like. A fixed semiconductor memory or the like that is fixed is used.
[0031]
The plurality of input switches are for supplying various instruction signals to the system controller 3 via the signal generation circuit 33 as described above. The system controller 3 receives an instruction signal from the input switch transmitted through the signal generation circuit 33, controls predetermined components and the like, and executes a predetermined operation according to the input instruction signal. The electronic camera is controlled as described above.
[0032]
As the various switches constituting the input switch, for example, a release SW1 that generates a predetermined instruction signal for executing a photographing preparation operation such as photometry and AF corresponding to a release member 53 shown in FIG. An operation suitable for close-up photography in conjunction with a release SW2 that generates a predetermined instruction signal for executing a photography operation corresponding to the member 53, a photography mode selection member (not shown) or a macro photography operation member (not shown) A macro switch 37 that generates an instruction signal for switching between a close-up shooting mode for performing AF control and a normal shooting mode for performing normal shooting, and a zoom operation member (not shown) for setting a shooting range at the time of shooting. Then, a zoom that generates an instruction signal for setting a desired zoom ratio by controlling a desired zoom operation (zoom operation) Switch 36, there is an image size determination start switch 38 or the like for starting the image size information determination sequence of the taking lens 2.
[0033]
The storage unit 49 on the photographic lens 2 side stores various information related to the photographic optical system constituting the photographic lens 2 as described above, that is, information such as distortion of the lens and information related to the image circle. Various information such as range information of the image circle in the optical system and a reduction amount (dimming rate) of the peripheral light amount in a predetermined region in the image circle are stored in advance. In the following description, various pieces of information related to the photographing optical system, and various pieces of information unique to the photographing optical system are collectively referred to as image circle information.
[0034]
Then, the system controller 3 on the camera body 1 side stores necessary information via the I / F unit 42 as necessary by the electrical contact 2a, 2b and 1a, 1b. 49 can be read.
[0035]
FIG. 2 is a perspective view showing an appearance of a single-lens reflex electronic camera having the above-described configuration, and shows a state in which the photographing lens 2 is detached from the camera body 1 of the electronic camera.
[0036]
As shown in FIG. 2, the camera body 1 has a screen set on one side of the upper surface thereof based on the image size information of the release member 53, the image size determination start switch 38 and the photographing lens 2. An LCD 26 or the like for displaying the size is disposed, a camera-side mount 51 or the like is disposed in the center of the front surface of the camera body 1, and the photographic lens 2 is detachably attached to the camera-side mount 51. The photographic lens side mount 52 etc. Arrangement Has been.
[0037]
Further, a photographic lens mounting detection pin 50 for detecting that the photographic lens 2 is mounted is disposed on a part of the front surface of the camera-side mount 51, and when the photographic lens 2 is mounted. The mounting detection pin 50 is pushed in, and the system controller 3 in the camera body is shown in FIG. Lens attachment / detachment detector 41 transmits a mounting confirmation signal. Release switches SW1 and SW2 are arranged inside the release member 53. The switch SW1 in FIG. 1 is turned on by the first stroke, and the switch SW2 is turned on by the second stroke.
[0038]
Furthermore, when the photographic lens 2 is attached to the camera body 1, electrical contacts 1a, 1b, 2a, 2b that are in contact with each other are provided on a part of the facing surface of the camera side mount 51 and the photographic lens 2, respectively. In addition, as described above, the camera body 1 and the photographing lens 2 are electrically connected.
[0039]
FIG. 3 is a diagram showing a display example on the LCD 26 shown in FIGS. 1 and 2.
[0040]
The display on the LCD 26 is linked to the image size information of the taking lens 2, and when the image size information is “large”, “medium”, and “small”, the LCD 26 has FIGS. 3 (a) and 3 (b). , (C), the display is switched so that the icons “L”, “M”, and “N” are displayed. In addition, when a lens having no image size information is attached, as shown in FIG. 3D, all three icons representing the image size are displayed blinking, and a lens without image size information is shown to the photographer. Warning that it is installed. The warning is performed not only by display but also by sounding the sounding body 40 at the same time.
[0041]
Here, the system controller 3 will be briefly described.
[0042]
First, when a lens attachment signal is generated in the lens attachment / detachment detection unit 41 when the photographing lens 2 is attached to the camera body 1 and the attachment detection pin 50 is pushed in, the system controller 3 displays the image size of the attached photographing lens 2. A command for obtaining information is transmitted to a lens system controller (not shown) on the photographic lens 2 side, and the lens system controller that receives this command reads image size information of the mounted photographic lens 2 from the storage unit 49, It transmits to the system controller 3 on the camera body 1 side. In FIG. 1, the lens system controller is not shown for simplification of the drawing, and the command of the system controller 3 on the camera body 1 side is shown to be sent directly to the storage unit 49 via the I / F unit 42. However, the actual configuration is as described above.
[0043]
Upon receiving the image size information, the system controller 3 identifies the size of the imaging screen (imaging screen) based on the size of the image size determined from the image size information and the image data of the imaging lens 2, and controls according to the information. A signal is sent to each unit that displays the exposure control, field frame switching, and imaging screen size. Further, the system controller 3 determines whether or not the image size of the mounted photographic lens 2 is as it is and is suitable for the imaging range of the imaging element 22 on the camera body 1 side. By performing predetermined signal processing on an image signal representing an image corresponding to a predetermined range of an image on the image pickup element 22 formed by a light beam passing through 2, the image size of the photographing lens 2 and the camera It has an electronic zoom function that adapts the imaging range of the imaging element 22 on the main body 1 side.
[0044]
FIG. 4 is a diagram showing the configuration of an optical system and a photometric optical system in which the field frame can be switched.
[0045]
The optical system in which the field frame can be switched includes a mirror 6 that guides a light beam through the photographing lens 2 (zoom lens 43, diaphragm 44, focus lens 45) to the photographing element 22 side and the finder side, Focus plate 8 and Transmission type LCD 9, a pentaprism 10, a photometric mirror 11, which is a half mirror that guides a part of the light flux toward the photographer to the photometric sensor 13, and an eyepiece 15, and the transmissive liquid crystal plate 9 Is the incident surface of the pentaprism 10 and the focusing plate 8 1 is connected to the LCD control circuit 27 shown in FIG. 1 to control the display state, and the display switching of the size of the field frame corresponding to the size of the imaging screen is electrically performed. It is configured to be able to do.
[0046]
This transmissive liquid crystal plate 9 Field frame display for large screen, field frame display for medium screen, small FIG. 5 (a), (b), and (c) show the field frame display on the screen. Such switching of the field frame is performed in accordance with an instruction from the system controller 3 at the stage where the imaging screen size is determined.
[0047]
At the time of observation, the light beam from the subject that has passed through the photographic lens 2 is reflected upward by a mirror 6 obliquely provided at an angle of 45 degrees on the optical axis o behind the photographic lens 2. A subject image is formed on the focusing plate 8 disposed above. The subject image and the field frame can be visually recognized by the photographer's eyes through the pentaprism 10 and the eyepiece 15 disposed above the focus plate 8.
[0048]
Next, the configuration of the photometric optical system will be described.
[0049]
In this embodiment, the light beam from the focus plate 8 reflected by the pentaprism 10 is divided by a photometric mirror 11 that is obliquely inclined at 45 degrees just before the eyepiece lens 15. That is, a part of the light flux of the focusing plate 8 passes straight toward the eyepiece lens 15 by the photometric mirror 11, but the rest is reflected upward in FIG. The light beam reflected upward passes through the photometric lens 12 arranged above the photometric mirror 11, and enters the photometric sensor 13 of 432 divisions arranged above it. The subject luminance in each range divided by 432 is measured. The 432-divided photometric sensor 13 is optically provided at a position equivalent to the image plane of the image sensor 22.
[0050]
The photometric system including the photometric optical system described above includes a 432-divided photometric sensor 13 which is a divided photometric unit, and a photometric circuit 14 which converts the detected current of each area of the photometric sensor 13 into a voltage and sends it to the system controller 3. Each area from the photometry circuit 14 is set for the photometry area of the portion that is set as the photometry area while setting the ineffective portion of the photometry sensor 13 based on the read image size information (switching the field frame). The output voltage of each group is A / D converted, and each area is grouped with respect to a portion that is effective as a photometric area, and the output voltage of each group is determined by a coefficient corresponding to the size of the image size of the photographing lens 2. The system controller 3 performs exposure value calculation by changing the weighting.
[0051]
As described above, in this embodiment, the 432-divided photometric sensor 13 is used as the divided photometric unit.
[0052]
FIG. 6 is a diagram for explaining the divided shape of the light receiving surface of the 432-divided photometric sensor 13.
[0053]
The photometric sensor 13 has a light receiving surface divided into A1, A2,..., A24, B1,. The entire range of the 432-divided photometric sensor 13 corresponds to an imaging range when a photographing lens having a large image size is attached to the camera body 1.
[0054]
Detected currents from the areas A1 to A24, B1 to B24,..., R1 to R24 of the photometric sensor 13 are input to the photometric circuit 14 shown in FIG. Then, the photometric circuit 14 converts the detected currents of the areas A1 to A24, B1 to 24,..., R1 to R24 of the input 432-divided photometric sensor 13 into detection voltages and outputs them to the system controller 3. . The system controller 3 also displays image size information of the taking lens 2. The Based on this, the ineffective area of the 432-division photometric sensor 13 is set as described above.
[0055]
FIG. 7 is a diagram showing the photometric effective area of the photometric sensor 13. The photometric effective area of the 432-divided photometric sensor 13 includes the central part A, the first peripheral part B that is the periphery of the central part A, the first The first peripheral portion B is grouped into second peripheral portions C arranged outside the peripheral portion B (hereinafter also referred to as groups A, B, and C).
[0056]
The system controller 3 performs A / D conversion on each detection voltage from the photometry circuit 14 and takes it in as a digital signal. Each digital signal in the grouped area corresponds to the image size of the photographing lens 2. Weighting is performed, and an optimal subject brightness is calculated to determine an exposure value.
[0057]
Next, the relationship between the image size size of the 432-divided photometric sensor 13 and the photographing lens 2 and the grouping of photometric areas will be described with reference to FIGS.
[0058]
The circles written in FIG. 8 indicate the effective imaging range in the image circle when the image size is large, medium, and small, and these circles are represented on the 432 division photometric sensor 13. The “image size (large)”, “image size (medium)”, and “image size (small)” circles are effective imaging ranges for each image size. Range).
[0059]
FIG. 9 is a diagram for explaining the photometry area used at the time of “image size (large)”. The photometry area at this time is “the photometry area at the time of image size (large) (imaging range)”. The entire photometric sensor 13 is divided into 432 parts. Accordingly, the photometry areas at this time are grouped into group A, group B, and group C shown in the corresponding part of FIG. At the time of exposure calculation, the system controller 3 weights the photometric value for each photometric area.
[0060]
Specifically, when “image size (large)” is set, the weighting coefficients a, b, and c given to the groups A to C of the photometric sensor 13 are a = 1, b = 1, and c = 0.8. .
[0061]
FIG. 10 is a diagram for explaining the photometry area used at the time of “image size (medium)”. The photometry area at this time is “the photometry area (image pickup range) at the time of image size (medium)”. The inside is indicated by a rectangle. The photometry areas at this time are grouped into group A, group B, and group C shown in the corresponding part of FIG. In the exposure calculation, the system controller 3 weights the photometric value for each photometric area.
[0062]
Specifically, when “image size (medium)” is set, the weighting coefficients a, b, and c given to each group of the photometric sensors 13 are a = 1, b = 1, and c = 0.8.
[0063]
FIG. 11 is a diagram for explaining a photometric area used when “image size (small)”. The photometric area at this time is “photometric area (imaging range) when image size (small)”. The inside is indicated by a rectangle. The photometry areas at this time are grouped into group A, group B, and group C shown in the corresponding part of FIG. In the exposure calculation, the system controller 3 weights the photometric value for each photometric area.
[0064]
For more information, see “Image Size ( small ) ", The weighting coefficients a, b, and c given to the groups of the photometric sensors 13 are a = 1, b = 1, and c = 0.8.
[0065]
The imaging range on the image sensor 22 for each of the large, medium, and small image sizes is also equivalent to each of the photometric areas.
[0066]
FIG. 12 is a flowchart showing the flow up to the setting of exposure information. The non-effective area of the 432-division photometry sensor 13 is set, the effective area is grouped, and the weighting for each group of photometry areas for each image size is performed. This figure mainly shows how the subject brightness is set until the optimum subject brightness is calculated for the image size of the taking lens 2.
[0067]
In FIG. 12, the sequence is started from step # 1001, first, at step # 1002, information such as each setting flag is initialized, and at the next step # 1003, it is determined whether or not the taking lens 2 is mounted. If it is determined that it is attached, the process proceeds to step # 1004. If it is not attached, step # 1003 is repeated.
[0068]
In step # 1004, the strobe mode is set and the image size of the taking lens 2 is read. In the strobe mode, “low brightness automatic light emission” → “forced light emission” → in accordance with a pressing operation of a strobe mode setting switch (not shown) connected to the signal generation circuit 10 (assuming a push button switch in the present embodiment) → It is set by scrolling in a loop in the order of “low luminance automatic light emission” mode from “light emission stop” again. However, at the time of initialization, the low luminance automatic light emission mode is set. Further, as described above, the image size information of the taking lens 2 is read into the system controller 3 by communication via the I / F unit 42 with the image size information stored in the storage unit 49 in the taking lens 2. .
[0069]
When the setting of the strobe mode and the image size is completed, the process proceeds to step # 1005. 432 The photometric values VA1 to VA24, VB1 to 24,..., VR1 to VR24 for each area in the divided ranges A1 to A24, B1 to 24,. Then, in the next step # 1006, the process jumps to a subroutine for performing photometry area grouping and weighting.
[0070]
FIG. 13 shows the grouping and weighting subroutine.
[0071]
This grouping and weighting subroutine proceeds with the processing using the image size information of the photographing lens 2 obtained in step # 1004 and the photometric values obtained by the photometric sensor 13 in step # 1005. It will be.
[0072]
In step # 1101, a grouping and weighting subroutine is started. First, in step # 1102, the image size information is “image size (large)”, “image size (medium)”, or “image size (small)”. Judgment is made. As a result, if “image size (large)”, the process proceeds to step # 1111. If “image size (medium)”, the process proceeds to step # 1111. # 1103 Go to step and if “image size (small)”, step # 1107 Proceed to
[0073]
If it is determined that “image size (large)” in step # 1102 and the process proceeds to step # 1111 here, since it is the case of “image size (large)”, all areas of the 432-division photometry sensor 13 are valid. Since this is an area, the grouping process is performed without setting the area outside the photometric range. In the grouping process, as shown in FIG. G15 , H10 H15 , ..., L10 L15 Set. The first peripheral part B (group B) around the central part A sets D7 to D18, E7 to E18,..., O7 to O18. The second peripheral part C (group C) arranged outside the first peripheral part B sets A1 to A24, B1 to B24,..., R1 to R24.
[0074]
Then, in the next step # 1112 Each group AC Is set to a = 1, b = 1, and c = 0.8, and the process proceeds to step # 1113.
[0075]
In step # 1113, first, a photometric value for each group is calculated. The photometric value VA of group A is the photometric value VG10 of each area in group A. VG15 , VH10 VH15 , VL10 VL15 Is obtained by accumulating. The photometric value VB of group B is obtained by integrating the photometric values VD7 to VD18, VE7 to VE18,..., VO7 to VO18 of each area in group B. The photometric value VC of the group C is obtained by integrating the photometric values VA1 to VA24, VB1 to VB24,..., VR1 to VR24 of each area in the group C. Next, a backlight-determined central photometric value Sv weighted by the weighting coefficient a with respect to the photometric value VA of the central portion A, which is used to determine backlight in step # 1011 of FIG. Backlight obtained based on values weighted by the weighting coefficients b and c for the photometric values VB and VC in the photometric range other than the central portion A (the first peripheral portion B and the second peripheral portion C). A determination peripheral photometric value BCv is set.
[0076]
Specifically, the central photometric value Sv, the peripheral photometric value BCv for backlight determination,
Sv = VA × a
BCv = VB × b + VC × c
And go to Step # 1114.
[0077]
If it is determined in step # 1102 that the image size is “medium” and the process proceeds to step # 1103, 432-division is performed based on the image size information of the photographing lens 2 obtained in step # 1004. The ineffective area of the photometric sensor 13 is set. In the case of “image size (medium)”, the area written in the frame of step # 1103 is an ineffective area.
[0078]
In the subsequent step # 1104, grouping processing is performed for an effective photometric area. In the grouping process, as shown in FIG. 10, the central portion A sets H11 to H14, I11 to I14, J11 to J14, and K11 to K14. The first peripheral portion B that is the periphery of the central portion A sets F9 to F16, G9 to G16,..., M9 to M16. The second peripheral portion C arranged outside the first peripheral portion B sets D5 to D20, E5 to E20,..., O5 to O20. In the next step # 1105, For each group A to C The weighting coefficients are set to a = 1, b = 1, and c = 0.8, and the process proceeds to step # 1106.
[0079]
In step # 1106, the photometric value for each group is calculated first. The photometric value VA of group A is obtained by integrating the photometric values VH11 to VH14, VI11 to VI14, VJ11 to VJ14, and VK11 to VK14 of each area in group A. The photometric value VB of group B is obtained by integrating the photometric values VF9 to VF16, VG9 to VG16,..., VM9 to VM16 of each area in group B. The photometric value VC of the group C is obtained by integrating the photometric values VD5 to VD20, VE5 to VE20,..., VO5 to O20 of each area in the group C. Next, a central photometric value Sv and a backlight photometric peripheral photometric value BCv similar to those described above are used to determine backlight in step # 1011 of FIG.
[0080]
Specifically, the central photometric value Sv and the peripheral photometric value BCv for backlight determination
Sv = VA × a
BCv = VB × b + VC × c
And go to Step # 1114.
[0081]
If it is determined in step # 1102 that “image size (small)” and the process proceeds to step # 1107, based on the image size information of the taking lens 2 obtained in step # 1004, 432 Split photometric sensor 13 Set the ineffective area of. Also, “Image size ( small In the case of ")", the area written in the frame of step # 1107 becomes the ineffective area, and becomes A1 to A24, B1 to B24, ..., R1 to R24.
[0082]
Next, in step # 1108, grouping processing is performed for an effective photometric area. In the grouping process, as shown in FIG. 11, the central portion A sets I12, I13, J12, and J13. The first peripheral portion B that is the periphery of the central portion A sets H11 to H14, I11, I14, J11, J14, and K11 to K14. The second peripheral part C arranged outside the first peripheral part B sets G9 to G16, H9, H10, H15, H16,..., L9 to L16. In the next step # 1109, For each group A to C The weighting coefficients are set to a = 1, b = 1, and c = 0.8, and the process proceeds to step # 1110.
[0083]
In step # 1110, first, a photometric value for each group is calculated. The photometric value VA of the group A is obtained by integrating the photometric values VI12, VI13, VJ12, VJ13 of each area of the group A. The photometric value VB of group B is obtained by integrating the photometric values VH11 to VH14, VI11, VI14, VJ11, VJ14, VK11 to VK14 of each area in group B. The photometric value VC of group C is obtained by integrating the photometric values VG9 to VG16, VH9, VH10, VH15,..., VL9 to VL16 of each area in group C. Next, the backlight determination central photometric value Sv and the backlight determination peripheral photometric value BCv, which are used to determine backlight in step # 1011 of FIG. 12 described later, are set.
[0084]
Specifically, the central photometric value Sv, the peripheral photometric value BCv for backlight determination,
Sv = VA × a
BCv = VB × b + VC × c
And go to Step # 1114.
[0085]
Step # above 1113 When step # 1106 or step # 1110 is completed and the process proceeds to step # 1114, the corrected subject luminance Ev weighted according to the image size information of the photographing lens 2 is set. The corrected subject brightness Ev is obtained by multiplying the photometric values VA, VB, VC of the groups A, B, C set in the photometric sensor 13 by the weighting coefficients a, b, c and adding the respective terms.
Ev = VA × a + VB × b + VC × c
Ask more. Then, in the next step # 1115, the grouping and weighting subroutine is terminated, and the process returns to step # 1006 of the flowchart shown in FIG.
[0086]
Returning to FIG. 12, when returning from the weighting subroutine in step # 1006, the process proceeds to step # 1007. In step # 1007, the process jumps to the strobe mode determination subroutine. The strobe mode determination subroutine will be described with reference to the flowchart of FIG.
[0087]
In step # 1201 of FIG. 14, the strobe mode determination subroutine is started. First, in step # 1202, it is determined whether or not the strobe light emission stop is set in step # 1004 of FIG. As a result, if the flash firing stop is not set, step # 1204 , The flash emission flag FS is set (FS = 1 (strobe emission permission)), and the process advances to step # 1205. On the other hand, if the flash emission stop is set in step # 1202, step # 1203 The process proceeds to step # 1205 without setting the strobe light emission flag FS (FS = 0 (strobe light emission prohibited)).
[0088]
When the process proceeds to step # 1205, this strobe mode determination subroutine is terminated, and the process returns to step # 1007 in FIG.
[0089]
Returning to FIG. 12 again, when returning from the strobe mode determination subroutine in step # 1007, the process proceeds to step # 1008, in which the weighted corrected subject luminance value Ev with the set image size information is set from the predetermined luminance value E0. A low luminance determination is made as to whether or not it is low. As a result, if “Ev <E0” is low luminance, the process proceeds to step # 1009, where it is determined whether or not strobe light emission is permitted. If strobe light emission is permitted, the process proceeds to step # 1010. Light emission is set and the process proceeds to step # 1015 to end the present sequence. If the flash emission is not permitted in step # 1009, the process proceeds to step # 1014 described later.
[0090]
If it is determined in step # 1008 that “Ev <E0” is not satisfied, that is, the brightness is not low, the process proceeds to step # 1011 and the central photometric value Sv and the backlight photometric peripheral photometric value BCv obtained as described above are obtained. To determine backlight. That is, it is determined how much the backlight determination central photometry value Sv as the luminance near the center of the trimming range is smaller than the backlight determination peripheral photometry value BCv as the luminance around the trimming range. Is used as a reference to perform backlight determination based on whether or not the relationship of “BCv−Sv ≧ Ej” is satisfied. As a result, if it is determined that the vicinity of the center is not so dark and the relationship “BCv−Sv ≧ Ej” does not hold and the backlight is not backlit, the process proceeds to step # 1014. On the other hand, if the vicinity of the center is dark and the relationship of “BCv−Sv ≧ Ej” is established and it is determined that the backlight is back, the process proceeds to step # 1012.
[0091]
In step # 1012, it is determined whether or not strobe light emission is permitted. If the strobe light emission flag FS is set to “FS = 1” and strobe light emission is permitted, the process proceeds to step # 1010 described above. As described above, the flash emission is set, and the process proceeds to step # 1015 to complete this sequence. However, the flash emission flag FS is not set to “FS = 1” in step # 1012, and the flash emission is not performed. If not permitted, the process proceeds to step # 1013.
[0092]
In step # 1013, the weighted corrected subject luminance value Ev of the entire trimming range is corrected for backlight. In the backlight correction, the weighted corrected subject luminance value Ev of the entire trimming range is decreased to be close to the weighted central luminance value Sv near the center, thereby causing an underexposure near the center with respect to the determination that the center is dark. Make up. For this reason, the luminance value obtained by subtracting the backlight correction predetermined luminance value Eh from the luminance value Ev subjected to the same weight correction is newly set as the backlight correction luminance value Ev, that is,
Ev = Ev−Eh
Then, the process proceeds to step # 1014.
[0093]
Finally, in step # 1014, the shutter speed and aperture value are set based on the luminance value Ev set in each condition, and the process proceeds to step # 1015, and this sequence is completed.
[0094]
According to the above embodiment, the interchangeable photographic lens 2 having a different image size can be attached to the camera body 1, and the electronic zoom that enlarges the image corresponding to the predetermined range of the subject image on the photographic element 22 is performed. In the electronic camera having the function of adapting the image size of the taking lens 2 to the imaging range of the camera body 1, for example, divided photometry divided into 432 photometric areas in order to measure the exposure amount to the image sensor 22. A photometric sensor 13 as a means and a photometric area used by the photometric sensor 13 for photometry are selected based on information representing the image size of the photographic lens 2, and appropriate photometry even when photographic lenses having different image sizes are attached. Metering is performed in the area so that exposure control to the image sensor 22 can be performed with an appropriate exposure amount (steps # 1004 to # 101 in FIG. 12). ) Since it is configured, as either of the taking lens is mounted, there is no vignetting in accordance with the size of the image size of the photographic lens 2, and it is possible to obtain an image data of a proper exposure.
[0095]
In other words, it is possible to calculate an optimum exposure value using the photometric sensor 13 having a photometric area whose size does not correspond to the image size of the photographing lens 2 on a one-to-one basis.
[0096]
In the above embodiment, the 432-divided photometric sensor 13 is used as the photometric sensor, but the number of divisions may be plural. Although the exposure value is determined before entering the shutter sequence, it may be used in real-time integration (direct photometry).
[0097]
【The invention's effect】
As described above, according to the present invention, in an electronic camera capable of mounting an interchangeable lens having a different image size, an appropriate photometric area can be set according to the image size information of the mounted interchangeable lens. Can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a digital camera system according to an embodiment of the present invention.
2 is a perspective view showing a digital camera body and a photographing lens in FIG. 1. FIG.
FIG. 3 is an optical layout diagram for explaining a finder and a photometric optical system in the embodiment of the present invention.
FIG. 4 is a diagram for explaining a change in finder field frame in the embodiment of the present invention.
FIG. 5 is a diagram for explaining imaging size display in the embodiment of the present invention;
FIG. 6 is a diagram for explaining a photometric sensor division shape in the embodiment of the present invention.
FIG. 7 is a diagram for explaining grouping shapes of photometric sensors in the embodiment of the present invention.
FIG. 8 is a diagram for explaining a relationship between a photometric sensor and an image size in the embodiment of the present invention.
FIG. 9 is a diagram showing a relationship between a photometric sensor and an image size when the image size is large in the embodiment of the present invention.
FIG. 10 is a diagram showing a relationship between a photometric sensor and an image size when the image size is in the embodiment of the present invention.
FIG. 11 is a diagram showing a relationship between a photometric sensor and an image size when the image size is small in the embodiment of the present invention.
FIG. 12 is a flowchart showing a photometric operation in the embodiment of the present invention.
FIG. 13 is a flowchart for explaining photometric area selection and grouping in the embodiment of the present invention;
FIG. 14 is a flowchart showing an operation when setting a strobe in the embodiment of the present invention;
FIG. 15 is a diagram showing grouping of photometric sensors in the embodiment of the present invention.
[Explanation of symbols]
1 Camera body
2 Photo lens
3 System controller
4 Shutter
5 Shutter control circuit
6 Mirror
7 Mirror control circuit
8 Transmission type liquid crystal plate
9 Focus plate
10 Penta prism
11 Photometric mirror
12 Photometric lens
13 Photometric sensor
14 Photometric circuit
15 Eyepiece
16 Attitude detection sensor
17 Distance sensor
18 Distance measuring circuit
19 Colorimetric sensor
20 A / D circuit for white balance
21 White balance control circuit
22 Image sensor
23 Imaging circuit
24 A / D conversion circuit
25 memory
27 LCD control circuit
26 LCD
28 Recording media
29 Image processing circuit
30 Compression / decompression circuit
31 Strobe
32 External I / F section
33 Signal generation circuit
34 Switch (SW1)
35 switch (SW2)
36 Zoom switch
37 Macro switch
38 Image size discrimination start switch
39 Drive circuit
40 pronunciation body
41 Lens attachment / detachment detector
42 I / F section
43 Zoom lens
44 Aperture
45 Focus lens
46 Zoom motor
47 Aperture actuator
48 AF motor
51 Camera side mount
52 Lens side mount

Claims (1)

A camera-side mount that can be combined with the lens-side mount of the interchangeable lens;
A divided photometric means for measuring light by dividing an area into a plurality of areas,
Among the plurality of photometric areas, the number of photometric areas used for measuring the photometric value used for controlling the exposure amount differs based on the image size information from the interchangeable lens, and the photometric area used for the measurement is an image sensor on the camera body side. An electronic camera characterized by being within the imaging range .

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