JPH06189188A - Video camera and photometric method therefor - Google Patents

Abstract

PURPOSE:To calculate a photometric value optimum for photographing an object at the time of macro photographing. CONSTITUTION:Whether or not a macro photographing mode is set by a macro setting button 9 and whether or not a macro lens adapter is mounted on a camera are judged. When the macro photographing is performed by the macro setting button 9 or the macro photographing is performed by mounting the macro lens adapter on the camera, the photometric value is calculated based on the luminance signal components of video signals outputted from almost entire the photographing area of a CCD 64. Exposure control is performed based on the calculated photometric value.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a video camera (including a still / movie video camera and a still video camera) that performs photometry of a subject using a video signal obtained from a solid-state electronic image pickup device and determines exposure conditions. And its photometric method.

[0002]

BACKGROUND ART In a camera having an automatic exposure (so-called AE) function, photometry is necessary to determine an exposure condition. There are various methods for photometry. One of them is to arrange a photometric element in front of the camera. Although this method has a simple configuration, it has an essential problem that the photometric area does not match the shooting area. This problem is particularly noticeable when the field of view is changed using a zoom lens. In order to solve this problem, it is necessary to change the photometric area of the photometric element in conjunction with the zoom lens of the imaging system, which requires a large-scale mechanism.

A method in which a photometric element is incorporated in the image pickup optical system so that the photometric area coincides with the image pickup area (so-called TTL photometry).
There is also. This method requires a beam splitter, an optical path changing element, etc. in the image pickup optical system, which leads to a decrease in sensitivity due to an increase in size of the optical system and a decrease in light transmittance. Moreover, when a mirror is used, there are problems in terms of durability and reliability.

Therefore, in a video camera equipped with a solid-state electronic image pickup device (CCD or the like) to obtain a video signal representing a subject image, the video signal output from the solid-state electronic image pickup device is integrated over an appropriate photometric region. A method of obtaining a photometric value is considered. According to this method, there is an advantage that the image pickup area and the photometric area are completely coincident with each other, and an extra optical system for increasing the size is not required. Also,
By electrically processing the video signal obtained from the solid-state electronic image sensor, variations such as average photometry, partial photometry, and split photometry are possible, and it is possible to set the exposure conditions corresponding to various shooting environments. The range of applications expands.

For example, partial photometry is performed on the basis of a video signal obtained from a region near the center of the photographing region in which the main subject is relatively present. Such partial photometry has the advantage that the main subject is always properly exposed.

Some cameras are equipped with a zoom lens for macro photography (close-up photography), and a macro lens adapter for macro photography can be attached.
Some of them can be used for macro photography by attaching a lens adapter. Macro photography enables close-up photography of flowers.

However, when macro photography is performed, if a photometric value is calculated based on a video signal obtained from a region near the center of the photographing region and exposure conditions are determined, the center of the subject is particularly dark and auto A camera with a strobe function will be in daylight sync photography mode and a broken image will be captured. Even if the camera does not have an auto strobe function, the exposure conditions will not be correct,
The amount of exposure increases and the captured image becomes too bright.

An object of the present invention is to make it possible to calculate a relatively appropriate photometric value even when macro photography is set.

According to the present invention, there is provided a video camera including an image pickup optical system including a solid-state electronic image pickup device which converts an incident light image into a video signal and outputs the image signal, wherein the close-up photographing can be performed according to a setting. A luminance signal component extracting means for extracting a component relating to a luminance signal from a video signal output from the device, and a luminance signal component extracted by the luminance signal component extracting means for a photographing area defined by a light receiving area of the solid-state electronic image pickup device. Corresponding to the integration means for integrating over substantially the entire area, the close-up shooting determination means for determining whether close-up shooting is set, and the close-up shooting set by the close-up shooting determination means,
It is characterized by further comprising photometric value calculating means for calculating a photometric value based on the integrated luminance signal component integrated by the integrating means.

The photometric method of the present invention includes an image pickup optical system including a solid-state electronic image pickup device for converting an incident light image into a video signal and outputting the image signal, and a video image pickup apparatus capable of performing close-up photography according to the setting.
In the camera, a component related to a luminance signal is extracted from the video signal output from the solid-state electronic image pickup device, and the extracted component related to the luminance signal is integrated over almost the entire photographing region defined by the light-receiving region of the solid-state electronic image pickup device, It is characterized in that it is determined whether or not close-up photography is set, and in response to the determination that close-up photography is set, the photometric value is calculated based on the integrated luminance signal component that has been integrated.

The term "capable of close-up photography according to the setting" means that a lens adapter for close-up photography can be attached to a camera in which a lens adapter for close-up photography can be attached. In a camera with a built-in system, it means that it is set by a switch for close-up shooting.

According to the present invention, it is determined whether or not close-up photography is set, and when close-up photography is set, based on a component relating to a luminance signal extracted from a video signal obtained from almost the entire photographing area. The photometric value is calculated. Therefore, since partial metering is not performed,
Even if the main subject has a dark part, the photometric value calculation process based on that part is not performed, and a relatively appropriate photometric value is obtained. Therefore, even a camera with an auto strobe function does not enter the daylight sync mode, and a relatively properly exposed image can be obtained.

When the image pickup optical system of the video camera is an optical system capable of close-up photography, the video camera includes close-up photography setting means such as a close-up photography setting switch.
Therefore, in this case, the close-up photography setting is determined based on whether or not the close-up photography is set by the close-up photography setting means.

Further, depending on the camera, there is a camera to which a lens adapter for close-up photography for close-up photography can be attached. In such a camera, it is determined that the close-up shooting is set by detecting that the close-up shooting lens adapter is attached to the video camera.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the appearance of a camera and a macro adapter attached thereto. 2 to 4
Shows a macro adapter, FIG. 2 is a plan view, and FIG.
Is a front view and FIG. 4 is a side view. The macro adapter includes a strobe and can also be called a strobe adapter.

The camera 10 is a solid-state electronic image pickup device (for example, C
A still video camera in which a video signal representing a subject image output from the solid-state electronic image pickup device is magnetically or electronically fixed (recorded on a floppy disk or stored in a memory) using a CD. In this embodiment, a digital still camera is shown in which a video signal representing a subject image is converted into digital image data, data is compressed, and then stored in a semiconductor memory (built-in memory or removable card-shaped memory).

Mainly referring to FIG. 1, the camera 10 is provided with a shutter release button 11. The shutter release button 11 is of a two-step stroke type and has two switches SW1 and SW2. When the button 11 is pressed in the first stage, the switch SW1 is turned on, and in response to the ON signal of the switch SW1, various operations for preparing for photographing which will be described in detail later are started. When the button 11 is further pressed and the second stage is reached, the switch SW2 is turned on,
The photographing operation is started in response to the ON signal of the switch SW2.

The camera 10 also includes a macro shooting setting button 9, a tele, wide setting buttons 12A and 12B, a flash forced shooting setting button, a time setting button, a reproduction mode setting button, a compression ratio setting button, and the like. A display unit 14 that displays a state set by using various buttons of the setting unit 13 is provided.

The camera 10 is provided with an image pickup lens system 17, a finder 18 (see FIG. 2) and a distance measuring window 15 on its front surface.
In the distance measuring window 15, a light emitting diode (LED) that emits light for distance measurement, a light receiving element that receives reflected light from the subject (the LED and the light receiving element constitute a distance measuring sensor), etc. are provided. There is. When the macro adapter 30 is not attached, the camera 10 performs an automatic focusing control operation according to the distance information obtained by the distance measuring sensor.

The camera 10 further has a strobe circuit and its light emitting section 16. In contrast to the strobe circuit of the macro adapter 30, the strobe circuit of the camera will be called the built-in strobe circuit (see FIG. 5). Flash firing part 16
Can be raised and lowered, and when not in use, it falls so as to cover the imaging lens 17 and the finder 18, and becomes a cover thereof.

Mainly referring to FIGS. 2 to 4, the macro adapter 30 has a first portion which is L-shaped when viewed in plan.
It has 30A and a second portion 30B. These parts 30
A and 30B are foldably connected, and the second portion 30B
Can be folded along the first portion 30A.

The macro adapter 30 is provided with a mounting screw 23. By turning the knob 23A of the screw 23, the tip end of the screw 23 is formed on the side surface of the camera 10, so that the screw 19 is screwed and the adapter 30 is attached and fixed to the camera 10.

The first portion 30A of the macro adapter 30 is also provided with a protrusion 21B forming an X contact 21 and a protrusion 22B forming a ground contact (hereinafter referred to as a G contact) 22. These protrusions 21B and 22B can move back and forth, and are normally urged outward by springs. Corresponding to these protrusions 21B and 22B, recesses or holes 21A and 22A are formed on the side surface of the camera 10. When the adapter 30 is attached to the camera 10, the protrusion 21B enters the hole 21A,
The protrusion 22B enters the hole 22A. Both the protrusions 21B and 22B are made of a conductive material, and the conductive material is also provided on the inner surfaces of the holes 21A and 22A. Therefore, the electrical connection of the X-contact 21 is prevented by the contact between the protrusions 21B and the hole 21A. The electrical connection of the G contact 22 is achieved by the contact between 22B and the hole 22A.

As described above, when the adapter 30 is not attached, the camera 10 performs focusing control based on the distance information obtained from the distance measuring sensor. However, in close-up photography of about 50 cm or less, the parallax between the optical axis of the distance measuring sensor and the optical axis of the imaging lens system 17 (and finder 18) becomes large, and the distance information of the distance measuring sensor indicates the distance to the subject. It does not always represent correctly.

Therefore, the adapter 30 has a distance setting switch.
32 are provided. In this embodiment, the following two steps of distances are set within the range of the closest distance by using the setting switch 32. Relatively short distance (eg 25 to 35 cm) switch SWA Relatively long distance (eg 35 to 45 cm) Switch SWB switch 32 is operated by the user and the switch (or contact) SWA is turned on when the relatively short distance is set. When a relatively long distance is set, the switch (or contact) SWB is turned on.

The strobe light emission amount and the strobe light irradiation direction in the macro adapter 30 are adjusted according to the distance set by the distance setting switch 32. Also,
The distance information set by the distance setting switch 32 is transmitted to the camera 10 through the X contact as described later,
Reference numeral 10 controls the focusing based on this distance information.

The first portion 30A of the adapter 30 further includes
A strobe switch 31 for setting whether or not to emit a strobe, and a charging completion indicator lamp 33 that lights up when strobe charging is completed are provided.

The second portion 30B of the adapter 30 has a photographing window in which the light emitting portion 36 of the adapter strobe and the lens 37 are built.
37A and finder 38 are provided. When the macro adapter 30 is attached to the camera 10, the optical axis of the lens 17 of the camera 10 and the optical axis of the lens 37 of the adapter 30 are
The optical axes of the finder 18 of 10 and the optical axis of the finder 38 of the adapter 30 coincide with each other.

As detailed below, the X contacts 21 and G
The following information is transmitted through the contact 22. From camera 10 to adapter 30: Strobe light emission signal X _{ON From} adapter 30 to camera 10: With or without adapter installed. Strobe switch 31 on / off status. Distance information set by distance setting switch 32. With / without charging.

FIG. 5 shows an example of an electrical configuration suitable for transmitting the above information.

The camera 10 includes a CPU 40. This C
PU40, in this embodiment, a built-in A / D converter, a divided voltage (input voltage) of the resistor divider below V _in the A /
CP converted into digital data by D converter
Captured by U40. CPU40 determines the state of the macro adapter 30 based on the digital data of the input voltage V _in (including the presence or absence of attachment), performs various controls for shooting based on the determination result. A / D conversion circuit is CPU40
Needless to say, it may be connected to the outside. CPU40
A clock signal is input from the clock 46 every one second to the shutter release button 11 (switch SW
1, SW2), various devices, circuits, units, and the like give various signals. The CPU 40 also outputs a light emission permission signal X _EN and a light emission signal X _ON for flash photography.

The resistance voltage dividing circuit comprises a resistance circuit on the camera side and a resistance circuit on the adapter side. For the resistance circuit on the camera side and the resistance circuit on the adapter side, the adapter 30
They are connected to each other by an X contact (protrusion 21B and hole 21A) and a G contact (protrusion 22B and hole 22A) when mounted on the.

On the camera side, a stabilizing power supply circuit 41 is provided to apply a predetermined standard voltage V _o (for example, 5 V) to the resistance voltage dividing circuit. This stabilized power supply circuit 41
Output of the shutter release button 11 is the switch SW1 of the first stage (or a contact interlocking with this switch SW1 or a semiconductor switching element controlled to perform the same operation as the switch SW1), and the first resistor R1. And a second resistor R2 connected in series to the ground. The connection point between the resistors R1 and R2 (hereinafter referred to as the input point) is connected to the input of the A / D conversion unit of the CPU 40. This input point is connected to the X contact 21 via the third resistor R3.

A switching element FET1 is further connected between the input point and the ground. This FET1
Is controlled to be turned on by the output of the AND circuit 43 which becomes H level when the light emission permission signal X _EN and the light emission signal X _ON are given from the CPU 40.

The built-in flash circuit 42 of the camera 10 is also A
It is activated through the transistor switching element TR1 controlled by the output of the ND circuit 43. It goes without saying that the strobe circuit 42 must operate to have its charging circuit completed.

In the adapter 30, the adapter side resistance circuit includes a fourth resistance R4, a distance setting information generating resistance circuit 53 and a strobe on / off information generating resistance circuit 51,
The resistor R4 and the circuits 53 and 51 are connected in series. The resistor R4 is connected to the X contact and the circuit 51 is connected to the ground. A voltage stabilizing capacitor C1 and a protective Zener diode ZD are connected between both ends of the resistor R4 and the ground.

The resistor circuit 53 comprises a fifth resistor R5 and a sixth resistor R6 connected in parallel.
R6 is switched by the distance setting switch 32. Switch (contact) SWA when a relatively short distance is set
Turns on, and the resistor R5 is connected to the resistor circuit. Switch (contact) SWB when a relatively long distance is set
Is turned on, and the resistor R6 is connected to the resistor circuit. These switches SWA and SWB may be contacts that interlock with the sliding of the knob of the distance setting switch 32, or may be realized by semiconductor switching elements.

The circuit 51 further includes a charging completion information generating resistance circuit 52. A changeover switch 31B (referred to as SWS) that is interlocked with the strobe switch 31 or controlled by the strobe switch 31 is provided. This switch SWS directly connects the circuit 53 to the ground when the strobe switch 31 is off. When the strobe switch 31 is turned on, a series circuit of a seventh resistor R7 and an eighth resistor R8 is connected between the circuit 53 and the ground.
The circuit 52 is composed of an eighth resistor R8 and a switching transistor TR2 which short-circuits it. The transistor TR2 is normally off, and is turned on when an H level charge completion signal is input from the strobe adapter circuit 50. The switch SWS may be composed of a transistor and connected so as to short-circuit the resistors R7 and R8 when turned on.

The strobe adapter 30 is a battery
57 (output voltage is 3 V, for example). When the strobe switch 31 is turned on, a switch 31A (or a contact or a semiconductor switching element) (also referred to as SWS) interlocked with this is turned on, and the voltage of the battery 57 is applied to the regulator 56. The output voltage of the regulator 56 is applied to the adapter strobe circuit 50, and charging of the charging circuit included in this circuit 50 is started. When the charging is completed, the charging completion signal is output as described above and the transistor TR2 is turned on.

The strobe activation circuit 54 includes a comparator 55. The output voltage of the regulator 56 is divided by the resistance circuit, and this voltage dividing circuit E1 is applied to the negative input terminal of the comparator 55. The output voltage of the regulator 56 is also divided by another resistance circuit, and the divided voltage E2 is applied to the positive input terminal of the comparator 55. E1> E
Since it is set to 2, the output of the comparator 55 (output of the starting circuit 54) is normally at L level. Also, the voltage E
Diode D1 between the voltage dividing point where 1 appears and resistor R4.
However, it is connected in a direction that prevents current from flowing from the resistor R4 to the voltage dividing point. When the strobe switch 31 is on, the cathode-side potential of the diode D1 (divided potential of the resistance voltage dividing circuit) is higher than the voltage E1 (for example, E1 = 2V). However, due to the presence of the diode D1, the resistance voltage divider circuit causes the comparator
No current flows into the negative input terminal of 55.

When the CPU 40 of the camera 10 gives a light emission signal X _ON , the FET 1 is turned on, so that the potential of the X contact becomes close to the ground level. Therefore, the potential (E1) on the anode side of the diode D1 becomes higher than that on the cathode side, the diode D1 conducts, and the input voltage of the negative input terminal of the comparator 55 decreases. As a result, the output of the comparator 55 is inverted to H level. The H level output of the comparator 55 is given to the strobe circuit 50 as a light emission start signal, and the strobe circuit 50 causes the light emitting unit
36 will fire a flash.

It is also possible to attach an adapter other than the macro adapter 30 to the camera 10. Macro adapter 30
A lens adapter called a wide converter can be considered as an adapter other than the above. An electrical configuration example of this wide converter is shown in FIG.

The wide converter 55 has a lens for wide photography and is connected to the camera 10 in the same manner as the strobe adapter described above. This wide converter
At 55, the projection 21C for the X contact and the projection 22C for the G contact are short-circuited. Therefore, when the wide converter 55 to the camera 10 is mounted, from the input point of the camera-side resistor circuit it will be grounded through the resistor R3, the input voltage V _in becomes almost 0 level. CPU40 cameras on the basis of the input voltage V _in, it is possible to recognize that the wide converter 55 is connected rather than the macro adapter. The CPU 40 sets the lens 17 to a wide lens.

Light emission signal X _ON from camera 10 to adapter 30
And the transmission of various information from the adapter 30 to the camera 10 will be described with reference to FIG.

In FIG. 5, an example of concrete voltage and resistance values is as follows. Output voltage of stabilized power supply circuit 41 V _o = 5V E1 = 2V R1 = 51kΩ R2 = 200 kΩ R3 = 1kΩ R4 = 1kΩ R5 = 10kΩ R6 = 33kΩ R7 = 39kΩ R8 = 68kΩ

The state of the adapter 30 is reflected as the value of the input voltage V _in of the A / D converter through the voltage dividing resistor circuit. It is possible to determine the status of the adapter 30 by checking the input voltage V _in. A / D conversion error of the A / D converter,
A zone for state determination is set as shown in FIG. 7 in consideration of variations in resistance, variations in voltage, and the like. Since the resistor divider output standard voltage V _o of the stabilized power supply circuit 41 of the camera 10 is applied, of the adapter 30 battery
Regardless of the output fluctuation of 57 and the output voltage drop, if the output voltage V _o of the power supply circuit 41 is stable, the accurate state determination can always be performed.

Zone A (V _in = 3.8 V or higher) It is determined that the adapter is not attached to the camera.

The input voltage V _in is given by the following equation.

[0049]

[Equation 1]

Zone B (2.83 to 3.30V) It is determined that the strobe switch 31 (SWS) is on and the strobe is charging (charging incomplete) (distance setting switch 32 (SWA, SWB) does not matter) .

In this case, the voltage dividing resistor circuit has a resistor R
1, R2, is constituted by R3, R4, R5 or R6, R7, R8, input voltage V _in is given by the following equation.

[0052]

[Equation 2]

Zone C (2.43 to 2.72 V) The strobe switch 31 (SWS) is turned on, and the distance setting switch 32 sets a relatively long distance (SWB on), and it is determined that strobe charging is completed.

The voltage dividing resistor circuit includes resistors R1, R2, R3.
It is composed of R4, R6 and R7, and the input voltage V _in is represented by the following equation.

[0055]

[Equation 3]

Zone D (2.05 to 2.36V) The strobe switch 31 (SWS) is turned on, the distance setting switch 32 sets a relatively short distance (SWA on), and it is determined that strobe charging is completed.

The voltage dividing resistor circuit includes resistors R1, R2, R3.
It is composed of R4, R5 and R7, and the input voltage V _in is expressed by the following equation.

[0058]

[Equation 4]

Zone E (1.7 to 2.0 V) The strobe switch 31 (SWS) is off, and the distance setting switch 32 sets a relatively long distance (SWB).
ON).

The voltage dividing resistor circuit includes resistors R1, R2, R3.
It is composed of R4 and R6, and the input voltage V _in is given by the following equation.

[0061]

[Equation 5]

Zone F (0.8 to 1.0 V) The strobe switch 31 (SWS) is off, and a relatively short distance is set by the distance setting switch 32 (SWA).
ON).

The voltage dividing resistor circuit includes resistors R1, R2, R3.
It is composed of R4 and R5, and the input voltage V _in is given by the following equation.

[0064]

[Equation 6]

Zone G (0.2 V or less) It is determined that the wide converter 55 is mounted.

FIG. 8 shows a processing procedure by the CPU 40 from the depression of the shutter release button 11 to the presence / absence of attachment of the adapter, the type of the adapter and the setting status of the adapter.

When the first-stage switch SW1 of the shutter release button 11 is turned on (step 101), the input voltage V _in is taken _in and converted into digital data (step 102). The CPU 40 determines in which of the zones A to F the digital data is located (steps 103 to 108).

When the input voltage V _in is in the A zone,
It is determined that the adapter is not attached (step 13
1).

When the input voltage V _in is in the B zone,
Although the adapter 30 is attached and the strobe switch 31 is turned on, it is determined that the photographing process cannot be started yet because the strobe is charging (step 141). Shutter·
Pressing the release button 11 to the second stage is prohibited. This may be a mechanism that mechanically blocks the pressing of the button 11 to the second stage, or even if the switch SW2 is turned on, it is ignored and the processing after the switch SW2 is turned on is not proceeded. May be realized. Further, the automatic focusing control based on the distance measuring sensor of the camera 10 is prohibited (step 142). Thereafter, it waits for the input clock signal from the clock 46 (step 143), a check of the input voltage V _in is performed again (step 102).

When the input voltage V _in is in the C zone,
It is determined that the adapter is attached, the flash is turned on, the flash is charged, and the set distance is relatively long (35 to 45 cm) (step 151). Further, when the input voltage V _in is in the D zone, the adapter mounting, flash on, flash charge completion, the set distance is determined relatively short-distance (25~35cm) (step 161). In these cases, waiting for the second-stage switch SW2 to be turned on, and since the camera 10 is a close-up shot, the image pickup lens 17 is suitable for the shooting distance set within the tele range and set by the adapter. In addition to being positioned, the exposure conditions are set to those suitable for flash photography. Further, in the adapter 30, a strobe light emission amount suitable for the set shooting distance is set, and an orientation of the light emitting unit 36 is set to an angle suitable for the set shooting distance. After this, the CPU 40 of the camera 10
When the light emission signal X _ON is output from the strobe circuit 50, the strobe circuit 50 is activated by the activation circuit 54, and the light emitting unit 36 emits light.

When the switch SW1 is turned on, it is determined that it is in the B zone, then it is determined that the strobe charging is completed and the zone is D, and the series of operations up to photographing under the strobe light emission and the input voltage V _in . An example of the changes is shown in FIG.

When the input voltage V _in is in the E zone,
The adapter is attached, the flash switch 31 is turned off, and the set distance is determined to be relatively long (step 171). When the input voltage V _in is in the F zone, the adapter is installed,
The strobe switch 31 is turned off, and the set distance is determined to be relatively short (step 181).

When the input voltage V _in is in the G zone,
It is determined that the wide converter 55 is installed (step 19).
1).

If the zone is neither the A zone nor the G zone, error processing, for example, display of error is performed.

FIG. 10 is a block diagram of a digital circuit of the embodiment
It is a block diagram which shows the electric constitution of a still camera.

A clock signal generation circuit (hereinafter referred to as CG) 61 has a clock signal CLK, a horizontal transfer pulse H for driving the horizontal transfer path of the CCD 64, a substrate removal pulse SUB for sweeping unnecessary charges, and an A field vertical transfer. A pulse VA and a B field vertical transfer pulse VB are generated. Further, the CG 61 generates a field index signal FI and an X timing signal XTM for strobe emission.

The clock signal CLK is given to a synchronizing signal generating circuit (hereinafter referred to as SSG) 62, and the SSG 62 generates a horizontal synchronizing signal HD and a vertical synchronizing signal VD based on this clock signal CLK and gives it to a CG 61.

The horizontal transfer pulse H is given to the CCD (solid-state electronic image pickup device) 64, and the substrate extraction pulse SUB and the A field vertical transfer pulse VA are passed through the V driver 65.
The B field vertical transfer pulse VB is applied to the CCD 64 via the V driver 66.

The field index signal FI, the X timing signal XTM and the horizontal synchronizing signal HD are the CPU
Given to 63. From the CPU 63 to the CG 61, a shutter enable signal TS indicating that the exposure condition has been set
An electronic shutter control signal TS1 for starting exposure in EN and CCD 64 is applied.

In the CCD 64, the substrate extraction pulses SUB, A
By the field vertical transfer pulse VA, the B field vertical transfer pulse VB, and the horizontal transfer pulse H, interlaced shooting is performed, and video signals of the A field and the B field (color sequential signals of GRGB) are alternately generated every one field period. Are sequentially read. The driving of the CCD 64 (imaging and reading of video signals) is performed at least at the time of photographing and in the photometric processing prior thereto.

The distance measuring circuit 20 including the light receiving element 20A included in the distance measuring window 15 is controlled by the CPU 40, and distance measuring data representing the distance to the object is given to the CPU 40. Focusing control of the imaging lens 17 is performed based on the distance measurement data.

Signals indicating the settings of the macro shooting setting button 9 and the tele and wide setting buttons 12A and 12B are given to the CPU 40. The photographing magnification of the imaging lens 17 is determined according to these settings.

The flash 16 emits light from the CG 61 to the CPU.
It is set based on the strobe light emission timing signal XTM given to 40. When the wide converter is attached to the camera 10, extremely wide-angle shooting is performed.
For this reason, when a wide converter is attached to the camera 10 and a flash is fired when shooting is performed, the angle of view of the shooting is wider than the irradiation angle of the flash firing, and the captured image becomes heterogeneous. Will end up. Therefore, in the digital electronic still camera 10, the CPU 40 controls so that the strobe light emission is prohibited when the wide converter is mounted on the camera.

The diaphragm 81 controlled by the diaphragm control circuit 82
A subject image is formed on the CCD 64 via the, and a video signal representing the subject image is output from the CCD 64.

The image signals of the A field and the B field output from the CCD 64 are given to a color separation circuit 68 through a correlated double sampling circuit (CDS) 67, and the three primary colors G (green), R Red) and B
It is separated into (blue) color signals.

The color signals G, R, and B are subjected to color balance adjustment by a gain control circuit (hereinafter referred to as GCA) 69, and then gradation correction is performed by a gamma correction circuit 70. Input to the sampling circuit 71.

The clamp and resampling circuit 71 is
The three color signals R, G, B are clamped and re-converted into GRGB color sequential signals by resampling. This color sequential signal is input to the gain control and blanking circuit 72. The gain control and blanking circuit 72 amplifies the color sequential signal to an appropriate level for recording and adds the blanking signal to it. The output signal of the circuit 72 is subsequently converted into digital image data by the A / D converter 73.

As will be described later in detail, prior to photographing, photometric processing and exposure control (control of iris and shutter speed) based on the photometric value are performed. This photometric processing is GCA69
Based on the output signal of Shooting is performed after such photometric processing and exposure control. Then, the video signal obtained from the CCD 64 by photographing is the above-mentioned circuits 70, 7
1, 72, and 73 to become digital image data, which is processed by an image data processing circuit (not shown) such as Y / C separation and data compression, and then recorded on a recording medium such as a memory card. Become.

For photometric processing, a Y _L combining circuit 74, a gate circuit 75, an integrating circuit 76 and an amplifying circuit 77 are provided. The CPU 40 outputs a window signal WIND that controls the gate circuit 75 and a reset signal HLRST that resets the integration circuit 76. These signals WIND and H
The timing of LRST will be described later. Further, in this embodiment, the CPU 40 has a built-in A / D converter 78.

The color signals R, G and B output from the gain control circuit 69 are added by the Y _L synthesizing circuit 74,
A relatively low frequency luminance signal Y _L (hereinafter simply referred to as luminance signal Y _L
Is generated). The luminance signal Y _L passes through the gate circuit 75 during the period in which the window signal WIND is applied during the required horizontal scanning period. The integrating circuit 76 is reset when the reset signal HLRST is given,
After that, the luminance signal Y _L input from the gate circuit 75 is integrated. The integrated signal of the integrating circuit 76 is amplified by the amplifying circuit 77, and immediately before the integrating circuit 76 is reset, the A /
Converted to digital integral data by D converter 78,
Captured by CPU 40.

In this embodiment, average photometry (hereinafter referred to as AV photometry) for measuring the average brightness of almost the entire field of view, and average brightness of the upper part of approximately 1/3 of the field of view are measured. Average upper metering (hereinafter referred to as AV upper metering), average lower metering (hereinafter referred to as AV lower metering) that measures the average brightness of the lower part of approximately 2/3 of the field of view, and brightness of the main subject in the field of view The spot photometry (hereinafter, referred to as SP photometry) for measuring is performed.

The SP metering is effective when the brightness of the main subject in the field of view and the brightness of the background are different and it is necessary to set an appropriate exposure condition according to the brightness. Further, in the case of outdoor photography, the sky is often captured in the upper area within the field of view. Therefore A
When V photometry is performed and the exposure condition is determined accordingly and the image is taken, the lower region in the visual field may become dark. In such a case, AV lower photometry is effective.

When the macro position is set by the macro setting button 9 or when the macro adapter is attached to the camera 10 and the main subject is photographed with a dark central portion, if the automatic exposure is performed, the spot metering value and Depending on the difference in brightness from the average photometric value, exposure control based on spot photometry or daytime sync photography may be performed, and a broken image may be taken.

Further, when the main subject is bright and the background is dark, the brightness level of the entire photographing area becomes low. Therefore, when the exposure control is performed by the AV photometry value based on the entire photographing area, the main subject image obtained by photographing is overexposed. Or the background becomes dark. Further, if the exposure control is performed by the SP photometric value of the area in the center of the shooting area, the background becomes dark. In any case, the proper image cannot be taken. Therefore, in this digital electronic still camera, as will be described later, it is possible to obtain an A based on the AV lower area of the lower 2/3 of the shooting area including the SP area.
The exposure is controlled using the V lower photometric value. The influence of the brightness value of the main subject and the influence of the background can be reduced, and relatively appropriate exposure control can be performed.

Since it is considered that the A field image and the B field image which form one frame represent the field images at substantially the same time point, in this embodiment, the video signal of the A field is AV upper photometry, AV lower photometry and For AV photometry, the B field video signal is used for SP photometry, respectively. The AV upper photometry is performed in almost the first half of the A field, and the AV lower photometry is performed in the latter half of the A field. AV metering value is A
It is obtained from the sum of the integrated value for V upper photometry and the integrated value for AV lower photometry.

Further, in this embodiment, the integration by the integration circuit 76 and the A / D conversion operation and addition processing by the A / D converter 78 are alternately performed every horizontal scanning period.

FIG. 11 shows an AV upper photometry area, an AV lower photometry area, an AV photometry area, and an SP photometry area, which are set in the photographing area 5 of the CCD 64, respectively.

The AV upper photometry area is almost 1 / th of the photographing area.
Set over the top of 3. In this embodiment, the AV upper photometry area is 40 in the horizontal direction after 16.15 μs has elapsed from the fall of the horizontal synchronizing signal HD (at the start of the horizontal scanning period).
It is set in the period of μs and is set in the vertical direction from the 35th horizontal scan line to the 100th horizontal scan line.

The AV lower photometry area is approximately 2 / of the photographing area.
3 over the lower region. In this embodiment, A
The V lower photometry area is set for a period of 40 μs after 16.15 μs has elapsed from the falling edge of the horizontal synchronizing signal HD (at the start of the horizontal scanning period) in the horizontal direction, and the vertical direction is from the 101st horizontal scanning line. It is set up to the 246th horizontal scan line.

The AV photometry area is a combination of the AV upper photometry area and the AV lower photometry area, and is basically set over almost the entire photographing area 5. In this embodiment, A
In the V photometry area, 40.degree.
The period is μs, and the vertical direction is from the 35th horizontal scanning line to the 246th horizontal scanning line.

The SP photometric area is set as a small area at an arbitrary position within the photographing area 5. In this embodiment, the SP metering area is set at the center of the photographing area 20, and the horizontal direction is 14 μs after 29.15 μs has elapsed from the fall of the horizontal synchronizing signal HD.
In the vertical direction from the 101st horizontal scan line to the
It is set up to the 208th horizontal scan line.

Both the AV upper photometry and the AV lower photometry are performed in the A field period, and only the setting lines of the horizontal scanning lines in the vertical direction are different. Because of this
Fig. 12 for both V upper metering and AV lower metering
As shown in FIG. 7, a window signal WIND having a pulse width of 40 μs is applied to the gate circuit 75 16.15 μs after the trailing edge of the 35th horizontal synchronizing signal HD. While the window signal WIND is being applied, the gate circuit 75 allows the input luminance signal Y _L to pass through, and the luminance signal Y _L is input to the integrating circuit 16.

The integrating circuit 76 has already been reset in the preceding field and integrates the luminance signal Y _L which has passed through the gate circuit 75 and is input. Window signal WIND
Becomes L level and the input of the luminance signal Y _{L to} the integrating circuit 76 is stopped, the integrated output of the integrating circuit 76 is held as it is and the integrated output of the integrating circuit 76 is A / D converted in the CPU 3. Converted into digital data by the device 78. In this embodiment, the time required for A / D conversion is
15 μs. After that, the integrating circuit 76 is reset by the horizontal line reset signal HLRST given from the CPU 40 to prepare for the next integrating operation.

A memory attached to the CPU 40 (for example, RA
M) has an AV upper integrated data storage area for storing data obtained by AV upper photometry and an AV lower integrated data storage area for storing data obtained by AV lower photometry.

The AV upper integrated data storage area is cleared in synchronization with the 34th horizontal synchronizing signal HD. A / D
The integrated value converted into digital data by the converter 78 is added to the previous data (which is cleared in the first case and is zero) and stored in this AV upper integrated data storage area.

The A / D conversion by the A / D converter 78, the reset of the integrating circuit 76, and the addition processing of the integrated data are as follows.
It is performed in the 36th horizontal scanning period.

As described above, the integration of the luminance signal Y _L by the integrating circuit 16 on one horizontal scanning line in the AV upper photometry area, and A / D conversion and integration of the integrated signal obtained by this integration The resetting of the circuit 76 and the addition of the integrated data to the memory are alternately repeated every horizontal scanning period. Then, this repetition is performed until the 100th horizontal scanning period.

Thus, the AV photometric value is obtained from the data stored in the AV upper integrated data storage area and the data stored in the AV lower integrated data storage area.

In SP photometry in the B field period, as shown in FIG. 13, a window signal WIND having a pulse width of 14 μs is given to the gate circuit 75 29.15 μs after the trailing edge of the 87th horizontal synchronizing signal HD. During this period, the integrating circuit 76 integrates the input luminance signal Y _L.
The window signal WIND is the 193rd signal every other horizontal scanning period.
It is performed until the second horizontal scanning period. A / D conversion of the integration signal output from the integration circuit 76 into integration data, integration circuit
Similar to the case of the AV photometry described above, the resetting of 76 and the addition of the integration data in the memory are performed in the next horizontal scanning period after the integration operation.

In this way, the luminance signal Y _L is integrated every other horizontal scanning period, and A / D conversion and other processing are performed in the next horizontal scanning period after the integration. Even if a D converter is used, it can be sufficiently dealt with. Then, even if the integration is performed every other horizontal scanning line, even SP photometry can be performed on 54 horizontal scanning lines so that a sufficient amount of integration data can be obtained to obtain a photometric value. .

In the above description, AV upper part, AV lower part and AV metering are performed in the A field period, and SP metering is performed in the B field period. Conversely, SP metering is performed in the A field period and AV upper part in the B field period. , AV lower part and AV metering may be performed, or needless to say, only AV metering (AV upper part, AV lower part metering) or SP metering may be carried out in both fields or one field. .

FIG. 14 is a flow chart showing a procedure for determining a photometric value used for exposure control of the digital electronic still camera.

By pressing down the shutter release button 11 in the first step, the photometric processing is performed using the Y _L combining circuit 74, the gate circuit 75, the integrating circuit 76, the amplifying circuit 77 and the like.
The photometric value, the AV upper photometric value, the AV lower photometric value, and the SP photometric value are obtained and stored in respective areas of the memory attached to the CPU 40. Further, the distance to the subject is calculated based on the distance measurement data provided from the distance measurement circuit 20.

[0114] Further voltage V _in values and macro settings button 9 to enter the CPU40, as shown in FIG. 8, tele, wide setting button 12A, a wide converter or microphone adapter in digital electronic still camera 10 based on the 12B It is determined whether or not it is installed, and whether macro, tele, or wide is set.

When the wide converter is mounted (YES in step 201), the shooting angle of view becomes larger than the strobe lighting angle, and strobe light is emitted only to a part of the shooting area, so strobe light emission is performed. Not (steps 213-219).

When the wide converter is not attached to the camera 10 (NO in step 201), the state of the strobe mode is checked. If the strobe mode is off, the strobe will not fire, and exposure control will be performed based on the AV lower photometric value or the AV photometric value (steps 213 to 219). If the strobe mode is set to the forced flash mode, the forced flash mode is set (step 21
2) The amount of emitted light is determined according to the distance to the subject, and exposure control is performed based on the amount of emitted light. If strobe mode is set to auto, macro setting, tele,
It is determined whether the wide setting or the macro adapter is installed (step 203).

If wide shooting is set by the wide setting button 12B, it is determined whether the AV photometric value is 8.6 EV or less (step 204). AV metering value is 8.6 EV
In the following cases (YES in step 204), it is not affected by the backlight and it is not necessary to consider them.
The exposure is controlled based on the photometric value (step 220), and the low-luminance light emission mode is set (step 221), and the strobe light is emitted. When the AV metering value is 8.6 EV or more, there is a possibility of backlighting, and when the exposure control based on the AV metering value is performed, the main subject may become dark, so either the AV metering value or the SP metering value Based on this, it is decided whether or not to perform the exposure control. For this determination, the SP photometric value is subtracted from the AV photometric value to calculate the photometric value difference .DELTA.EV (.DELTA.EV = AV-SP) (step 208).

If the difference ΔEV in photometric value is 1 or more, it is determined whether the distance to the main subject is less than 3 m (step 209). If the difference ΔEV in the photometric value is 1 or more, it is determined that the main subject is backlit, and if the distance to the main subject is 3 m or less, even if the exposure control is performed by the AV photometric value, the backlight is appropriate. Since shooting is not performed, daytime synchronized shooting is performed (steps 210 and 211).
As a result, the brightness of the main subject and the background is reduced, and relatively appropriate shooting is performed even with backlight. If the distance to the subject is more than 3m, the strobe light will not reach, so AV
The exposure is controlled based on the photometric value or the AV lower photometric value, and the strobe light is not emitted (steps 213 to 21).
9).

Even when tele shooting is set by the tele setting switch 12A, the magnitude of the AV photometric value is judged and the AV
When the photometric value is 9.6 EV or less, the low-luminance emission mode is set (YES in step 205, steps 220 and 201). When the AV photometric value is larger than 9.6 EV, the exposure control is set according to the difference ΔEV in the photometric value.

When the difference ΔEV of the photometric values is 0.5 ≦ ΔEV ≦ 1, the brightness of the main subject has a great influence on the entire photographing area, and therefore the exposure control is performed based on the SP photometric values (step 212). ).

When the difference ΔEV in the photometric value is less than 0.5, the main subject may be brighter than the background, and therefore the AV photometric value is subtracted from the SP photometric value to calculate the difference (step 213). If the difference is 0.5 EV or more, the AV photometric value and the AV lower photometric value are compared, and the AV photometric value is the AV
If it is larger than the lower photometric value, the exposure is controlled based on the AV lower photometric value (step 215). The lower AV area is SP
Since the area includes the area, the AV lower photometry value is affected by the SP photometry value, but is less affected by the background, so that relatively appropriate exposure control is performed.

It is determined whether the AF priority mode is set, and the AF priority AE program mode or the AE program mode is set (steps 216 to 218).

The difference obtained by subtracting the AV photometric value from the SP photometric value is
If 0.5 EV or less or the AV photometric value is larger than the AV lower photometric value, the exposure control is performed based on the AV photometric value (step 219).

When the macro position is set by the macro setting button 9, it is judged whether the AV photometric value is 12.0 EV or more (step 206). AV photometric value is 1
When it is 2.0 EV or less, exposure control is performed based on the AV photometry value (step 220) and strobe light is emitted (step 221). If the AV photometric value is larger than 12.0 EV, the flash is not emitted and the exposure is controlled based on the AV photometric value (step 219).

When the macro adapter is attached to the camera 10, the magnitude of the AV photometric value is judged (step 207), A
When the V photometric value is 13.0 EV or less, the exposure is controlled on the basis of the AV photometric value and the flash light emission photographing is performed (steps 220 and 221). When the AV photometric value is greater than 13.0 EV, the exposure is controlled based on the AV photometric value, and shooting is performed without strobe light emission (steps 216 to 219).

When the macro position is set as described above, or when the macro adapter is attached to the camera, the exposure control is performed based on the AV photometric value.
Therefore, even if you shoot a main subject with a dark central part, daytime sync photography and correction based on SP metering will not be performed,
A relatively appropriate captured image can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a camera to which a macro adapter is attached.

FIG. 2 is a plan view of a macro adapter.

FIG. 3 is a front view of a macro adapter.

FIG. 4 is a side view of a macro adapter.

FIG. 5 is a circuit diagram showing an electrical configuration of a camera and a macro adapter.

FIG. 6 is a circuit diagram showing an electrical configuration of a camera and a wide converter.

FIG. 7 shows each zone of input voltage representing various states of the adapter.

FIG. 8 is a flow chart showing a procedure of determination processing such as attachment of a CPU of a camera to an adapter.

FIG. 9 is a graph showing how the input voltage changes in the shooting sequence.

10 is a circuit diagram showing a more specific electrical configuration of a circuit portion required for photometry in the digital still video camera shown in FIG.

FIG. 11 shows a photometric area set within a shooting area.

FIG. 12 is a time chart when performing average photometry.

FIG. 13 is a time chart when spot photometry is performed.

FIG. 14 is a flowchart showing a procedure of processing for determining a photometric value to be used for exposure control by the CPU.

[Explanation of symbols]

10 Camera 40 CPU 64 CCD 74 Y _L Compositing circuit 75 Gate circuit 76 Integrating circuit

Front page continuation (72) Inventor Izumi Miyake 3-1146 Izumi, Asaka City, Saitama Prefecture Fuji Shashin Film Co., Ltd.

Claims (6)

[Claims] 1. A video camera having an imaging optical system including a solid-state electronic image pickup device for converting an incident light image into a video signal and outputting the image signal, wherein the video camera is capable of performing close-up photography according to a setting. Luminance signal component extracting means for extracting a component relating to a luminance signal from the output video signal, and a luminance signal component extracted by the luminance signal component extracting means for substantially the entire photographing area defined by the light receiving area of the solid-state electronic image sensor. Integrating means for integrating over, close-up photography determining means for determining whether close-up photography is set, and corresponding to the close-up photography determining means determining that close-up photography is set A video camera equipped with a photometric value calculating means for calculating a photometric value based on the integrated luminance signal component. 2. The image pickup optical system is capable of performing close-up photography, and the close-up photography setting means for setting close-up photography, and the close-up photography setting of the photography optical system when close-up photography is set by the close-up photography setting means. An adjusting means for adjusting the focal length for close-up photography is further provided, and the close-up photography determining means determines the close-up photography setting based on whether or not the close-up photography is set by the close-up photography setting means. The video camera according to claim 1. 3. The close-up lens adapter for close-up photography can be attached to the video camera, and the close-up photography determination means is attached to the video camera. The video camera according to claim 1, wherein the video camera is configured to determine that close-up shooting is set by detecting that the close-up shooting is set. 4. A video camera including an image pickup optical system including a solid-state electronic image pickup device for converting an incident light image into a video signal and outputting the image signal, and capable of performing close-up photography according to a setting. A component related to the luminance signal is extracted from the output video signal, and the extracted component related to the luminance signal is integrated over almost the entire photographing region defined by the light receiving region of the solid-state electronic image sensor to determine whether or not close-up photographing is set. In response to the determination that the close-up shooting is set,
A photometric method that calculates the photometric value based on the integrated luminance signal component. 5. The imaging optical system is capable of performing close-up photography, and when the close-up photography is set by the close-up photography setting means for setting the close-up photography, the focal length of the imaging optical system is set for close-up photography. The photometric method according to claim 4, wherein the close-up photographing setting is adjusted based on whether or not the close-up photographing is set by the close-up photographing setting means. 6. The video camera is capable of mounting a close-up lens adapter for close-up shooting, and detecting that the close-up lens adapter is mounted on the video camera. The photometric method according to claim 4, wherein it is determined that the close-up photography is set by.