JPH02177687A - Electronic still camera - Google Patents

Abstract

PURPOSE:To simplify the circuit constitution for control of color balance by fixing a control means at the daylight use to control the color balance of the video signal received from an image pickup means. CONSTITUTION:A control means is used to control the color balance of the video signal received from an image pickup means. Then the control means is fixed at the daylight use. A direct shooting action is attained in such a state where a subject can be photographed without using the flash light with the color balance kept at the daylight use. While the flash light is automatically emitted in the case the flash light is required for shooting. Thus the satisfactory photographing is always ensured with good color balance. Then the circuit constitution is simplified for an electronic still camera owing to a fact that the color balance control circuit is fixed at the daylight use. Furthermore the flash light is automatically emitted as necessary so that the beautiful images are always obtained with good color balance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic still camera equipped with a flash device.

[Prior Art] Conventionally, it has been known to automatically emit a flash when necessary in an electronic still camera using an imaging means such as a solid-state imaging device.

Incidentally, in order to always take clear pictures regardless of the type of light source, it is necessary to appropriately set the white balance (WB) in the image processing circuit according to the color temperature of the light source.

Examples include JP-A-58-147721, U.S. Pat. No. 4,499.487, U.S. Pat. No. 4,567.509, U.S. Pat.
The number, etc. will be displayed.

[Problems to be Solved by the Invention] However, the configuration of this type of color balance adjustment circuit is complicated and expensive.

SUMMARY OF THE INVENTION An object of the present invention is to simplify the circuit configuration for color balance adjustment as described above, and to provide a low-cost still video camera.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an imaging means for capturing an image of a subject, a determining means for determining whether the subject is in a state where it can be photographed without using flash light, and An electronic still camera equipped with a flash light emitting means for emitting a flash when the discriminating means determines that flash light is necessary, the electronic still camera having an adjusting means for adjusting the color balance of the video signal from the imaging means, the color balance adjustment The means is fixed for daylight use.

The determining means also includes means for measuring the color temperature of the subject and outputting information regarding the temperature, and when the information regarding the color temperature deviates from the color temperature fixed for daylight, the flash light It may be determined that the camera is not in a state where photography can be performed without using the camera.

The determination means also includes means for measuring brightness information of the subject and outputting the information, and when this brightness information is lower than a predetermined brightness (for example, when shooting in the morning, evening, on cloudy days, or indoors) etc.), it may be determined that the camera is not in a state where photography can be taken without using flash light.

[Function] According to the above configuration, the color balance remains fixed for daylight, and when the subject is in a state where it can be photographed without using flash light, the photograph is taken as is, and it is not necessary to take a photograph using flash light. When the flash is on, the flash fires automatically, allowing you to always take beautiful shots with good color balance.

[Effects of the Invention] According to the present invention, since the color balance adjustment circuit can be fixed for daylight use, the circuit configuration can be simplified and a low-cost still video camera can be realized. What's more, the flash fires automatically when necessary.
You can always get beautiful images with good color balance.

(Hereinafter, blank spaces) [Example] FIG. 1 shows a configuration diagram of an optical system according to an example of the present invention. In the figure, 1 is a photographing lens including a zoom lens, and 2 is a half mirror 3 with a low reflectance that guides a part of the light transmitted through the photographic lens 1 to a photometric sensor 6. Only the central portion is a half mirror, and the entire periphery is a half mirror. A main mirror that is a reflecting mirror and guides the light that has passed through the mirror 2 to the pentaprism 5. 4 is a sub-mirror that totally reflects the light that has passed through the center of the main mirror 3 and guides it to the focus detection sensor 7. 5 is the main mirror 3 8 is an optical low-pass filter, and 9 is a solid-state image sensor (for example, C0D) arranged in a matrix having a shutter function.

The photometric sensor 6 is a photoelectric conversion element (for example, 5PC)
It has two types of sensors: one that measures light at the center of the shooting screen spot-wise and one that measures light around the periphery of the shooting screen. Further, the sensor 6 is located at a position such that the distance Rb between the reflection point A of the half mirror 2 and the photometric point B of the sensor 6 is equal to the distance RC from the reflection point A to the imaging point C of the solid-state image sensor 9. It is arranged so as to be equivalent to performing photometry on the imaging surface of the solid-state image sensor 9. Additionally, the sensor 6 is placed in a position where the light it receives is not blocked regardless of whether the main mirror 3 is up or down, so that photometry can be performed at the same time when the solid-state image sensor 9 is exposed when the mirror is up. It has become.

The focus detection sensor 7 has, for example, two CCD line sensors that each receive images from different exit pupils of the photographic lens, and uses a phase difference detection method of the two images to determine the amount of focus shift or detect the amount of focus. It detects the amount of focus.

In the above configuration, when the photographer presses the shutter button halfway, the overseas system controller calculates the amount of defocus based on the output of the focus detection sensor 7,
Based on this, the photographing lens 1 is driven and focused. After the object has been focused, the photometric sensor 6 measures the brightness of the object, and based on the brightness information, the system controller determines the charge accumulation time of the solid-state image sensor 9 (that is, the shutter opening time), and the flash The necessity of the flash and the timing of the flash emission are calculated. When the photographer fully presses the shutter button to release the camera, the main mirror 3 is flipped up, the sub-mirror 4 is folded, and exposure to the solid-state image sensor 9 is started. That is, the solid-state image sensor 9 starts accumulating charges. Further, the photometric sensor 6 starts photometry at the same time as the charge accumulation in the solid-state image sensor 9, and when it is detected that the amount of photometry has reached the appropriate exposure value, it stops the charge accumulation in the solid-state image sensor 9, and The accumulated charge is transferred to the analog memory section and the photographing is completed.

In addition, in the configuration of this embodiment, while taking the configuration of an eye reflex camera, the solid-state image sensor 9 has a shutter function,
Furthermore, the diaphragm mechanism is removed in order to downsize the camera and simplify the TLL top. Therefore, the main mirror 3 and sub-mirror 4 placed in front of the solid-state image sensor 9 are configured to completely shield the low-pass filter 8 and the solid-state image sensor 9 from light, and form an image on a high-brightness object (for example, the sun). The color filter (not shown) provided on the front surface of the photographing element 9 may fade (
This prevents the solid-state image pickup device 9 from accumulating unnecessary charges at times other than when the camera is released.

Next, FIG. 2 shows the system configuration of this embodiment.

In the figure, 10 is a system controller (CPUI) that controls the sequence of the entire camera section, 23 is a system controller (CPU2) that controls the sequence of the video section, and 11 is a system controller that automatically drives the lens. This is a control circuit block consisting of a CCD line sensor for focus detection and an interface circuit section for focusing (AF) on the image.
/D conversion and output function are controlled.

Further, 12 is a DC/DC converter that generates different power supply voltages for each circuit block and supplies power; 13 is a clutch circuit for switching the power of the motor M to the photographing lens 1, the main mirror 3, and the sub-mirror 4; 14 is a light source such as an auxiliary light source (LED) of the AP to add contrast between light and dark to a dark subject where distance measurement is not possible and to enable distance measurement, and a light source such as an LED that flashes while the self-timer is operating; 15 is a motor M; The driving IC 516 is a photocoupler that generates a number of pulses corresponding to the amount of driving of the photographing lens. A photometric sensor 17 includes a sensor 17a that measures the brightness at the center of the photographic screen as a spot, and a sensor 17b that measures the brightness around the photographic screen except for the center. Also, 18 is a flash circuit, 19 is an LED display circuit 19a in the viewfinder, and an LCD on the top of the camera body.
A display circuit including a display circuit 19b; 20 a color temperature sensor circuit for measuring the color temperature of a light source illuminating a subject; 2;
Reference numeral 1 indicates switches including a switch linked to the shutter button and a mode changeover switch.

Here, each switch of the switches 21 is shown. SO is the main switch to prohibit camera operation when "open", and SL starts AE (auto exposure) and AP (auto focus). S2 is a release start switch.

In S3 and S4, correction amounts are set at the camera manufacturing stage according to variations in the imaging sensitivity (i.e., the sensitivity of the output voltage with respect to a constant exposure amount), which corresponds to the ISO sensitivity of the film of the solid-state wi image element 9, which is individually different. These switches S3 and S4 allow 2-bit signals <A, B
) are configured, and the corresponding correction values γ(Ev) are stored in the system controller 10.
When the bit signals (A, B) are input to the system controller 10, the system controller 10 outputs a correction value γ corresponding to the signal, and the luminance measured by the photometry sensor 17 is corrected. That is, the photometric sensor 17a performs photometry at the same time as shooting, and the timing of shutter release is controlled based on the photometric data, so the shutter speed is controlled by correcting the photometric data, and the imaging sensitivity is corrected. For example, (
0,0)=O,OEv, (0,1)=+0. 3Ev
, <1. 0)=-0,3Ev, <1. 1)=+
0.5Ev is stored in the memory, and the solid-state image sensor 9
If the imaging sensitivity of
, 1) is input to the system controller 10, the controller 10 outputs +〇, 3Ev corresponding to (0°1).
The correction value γ is output, and the photometric brightness of the photometric sensor 17 is +
Since the correction is made by 0.3 Ev, the shutter speed is increased by +0.3 Ev, the exposure amount is lowered by 0.3 Ev, and the variation in imaging sensitivity is corrected. Note that by increasing the number of switches and increasing the number of bits and storing correction values corresponding to each bit signal in memory, the amount of correction can be made finer.

S5 sets the selected date information with the first switch 55-1 for selecting date information of year, month, day, hour, and minute;
57-1 is a date switch consisting of a second switch 55-2 to be corrected; S6 is a deck low detection switch that detects the open/closed state of the deck; A floppy detection switch 57-2 detects whether write protection is selected by the write protection selection tab of the floppy disk.

S8 is a switch that detects whether or not the accessory slide copier is connected, and S9 is a switch that detects whether or not the accessory negative copier is connected.

S10 is a switch that detects the playback mode, and S11
is a field/frame switch that changes the recording format to field or frame.
312 is a zoom encoder switch group that monitors the focal length of the zoom lens.

S13 is a forced flash switch for forcing the flash to fire regardless of the brightness of the subject; 314
S15 is a flash prohibition switch for forcibly disabling the flash, and S15 is a mode changeover switch for switching between single/self-timer shooting mode.

Next, 22 is a control IC which converts the DC/DC converter 12 according to the control signal from the system controller 10.
It includes a control circuit for controlling the drive of each actuator such as the clutch 13, an A/D conversion circuit for photometry data based on the shutter speed of the solid-state image sensor 9 and the light emission timing 17 of the flash circuit 18, a proper exposure detection circuit, and the like.

To explain this control IC 22, the voltage control circuit 2
2a controls the startup and boost voltage of the DC/DC converter 12 using a DC/DC control signal, and the clutch control circuit 22b controls the clutch 13 using a clutch control signal.
The self-control circuit 22c controls the light emission of the light source 14 using a self-control signal, and the motor control circuit 22d controls the activation of the motor M using a motor control signal. In addition, the photo interrogator circuit 22e
counts the number of pulses according to the amount of lens rotation output from the photocoupler 16, and the system controller 10
This is what is output to. In addition, the amplifier circuits 22f1 and 22
f2 converts the output currents of the spot photometry sensor 17a and the peripheral photometry sensor 17b into logarithmically compressed voltage signals and outputs the signals, and the output signals are sent to the double integration control circuit 22g via the switch SWI. is input. The control circuit 22g also switches the switch SW1 to collect the analog signals output from the amplifier circuits 22f1 and 22f2, converts them into digital signals, and sequentially outputs them to the system controller 10.

22i is a circuit for causing the solid-state image sensor 9 to start exposure in response to the "shaft open" signal, and for determining whether the exposure amount has become appropriate based on a detection signal from the photometric sensor 17a. The configuration of the circuit 22i for detecting this proper exposure is such that the common terminal of the switch SWI is connected to the common terminal of the switch SWI via the adder M1.
connected to the base of transistor Q,
The emitter of is grounded, and its collector is connected to the inverting input terminal of comparator CP. Further, the collector of the transistor Q is connected to the negative electrode of a capacitor C, and the positive electrode of the capacitor C is connected to a power supply terminal Vcc (not shown). Further, the power supply terminal V cc is connected to the positive pole of the constant voltage source B, and the negative pole of the identification voltage source B is connected to the normal input terminal of the comparator CP.

In addition, a switch SW2 is connected between the positive and negative electrodes of the capacitor C.
is connected, and the switch SW2 is controlled to open and close by the output of "Shutter open" from the system controller 10.

In the proper exposure detection circuit 221, when the switch SW2 is switched from "closed" to "open" by the above-mentioned "shutter open" signal, the capacitor C is charged by the collector current of the transistor Q, and the negative terminal of the capacitor C is charged. Potential (V
) falls and becomes lower than the normal input terminal voltage (VO) of the comparator CP, the output of the comparator CP is inverted to detect proper exposure, and this detection result is used as a signal to command the shutter to "close". It outputs to the system controller 10 and the shutter control circuit 22n.

Next, the D/A conversion circuit 22h is connected to the system controller 1.
The brightness correction amount output from 0, for example, the above 130
It converts the adjustment amount for sensitivity variation adjustment from a digital signal to an analog signal, and the correction signal or adder M1
The signal is input to the photometric sensor 17 and added to the light reception signal of the photometric sensor 17.

The battery check circuit 22j checks the capacity of the battery. Further, the flash control circuit 221 outputs a "flash emission" trigger signal to the flash circuit 18 in response to a flash emission signal input from the system controller 10. In addition, the flash control circuit 22m
controls the charging of the main capacitor for light emission of the flash circuit 18 (hereinafter referred to as charging of the flash circuit) using the control signal of "boosting start", detects the charging state of the flash circuit 18, and charges the system controller 10. Outputs a completion signal.

22n is a shutter control circuit that outputs a shutter opening/closing signal;
Shutter "open" and "close" control signals are output to the system controller 23 and the time control circuit 24 in response to the "open" control signal and the detection signal of the proper exposure detection circuit 22i, or the forced termination signal from the system controller 10.

The time control circuit 24 is the same as the shutter control circuit 2.
The start and end of exposure of the solid-state image sensor 9 is controlled by the shutter "open" and "close" control signals inputted from the shutter 2n. The video processing control circuit 25 adjusts the video signal based on the gain correction amount input from the system controller 10 and the color temperature information input from the system controller 23. It also controls whether the number of recording tracks is one track or two tracks by the field/frame recording signal input from 3. Here, the details of the gain correction amount will be described later, but the "front light"
-1. OEv, 0
．． The correction amounts are 5Ev, +0.5Ev, +1, and OEv. Further, 26 is a recording magnetic head and disk, 2
A spindle motor 7 rotates the disk 26. Further, the system controller 23 sends map information (information on empty tracks and recording finished tracks), information indicating that the system controller 10 cannot accept switches such as recording, head feeding, etc.

Next, in FIG. 2 showing the system configuration, the operation of opening and closing the shutter will be explained focusing on the shutter control circuit 22n that outputs the shutter "open" and "close" signals, the appropriate exposure detection circuit 22i, and the system controller 10. do.

First, when the shutter "open" signal "H" is output from the system controller 10, it is input to SW2, and the capacitor of the detection circuit 22i is inputted. At the same time as charging of C is started, F is input to the XOR circuit 31 of the shutter control circuit 22n.

Since "L" is input to the input terminal at the other end of the EXOR circuit 31, the EXOR circuit 31 outputs H'' to the time controller 24 and the system controller 23 to start exposure of the solid-state image sensor 9. In addition, the system controller 10 allows the shutter to be activated only when a flash is necessary.
At the same time as the "open" signal is output, a time count for the flash emission time is started, and when the time count for the flash emission time ends, a flash trigger signal is output from the system controller 10 to the flash trigger circuit 221, and the flash starts emitting light. do.

Next, when the detection circuit 22i detects proper exposure, a shutter "close" signal "H" is output from the comparator CP to the system controller 10 and the OR circuit 32. OR circuit 32
receives the above-mentioned "H" output, and outputs "H" to the EXOR circuit 31, and the EXOR circuit 31 outputs "H" due to the shutter [open J signal "H"] input to the input terminal at the other end. , system controller 23 and time controller 24
to notify the end of exposure. In addition, if the timing at which the shutter "close" signal is output from the detection circuit 22i is later than a predetermined time (shake limit time), the system controller 1
A forced termination signal "H" is output from 0 to notify the end of exposure in the same way as the above operation.

The system controller 10 determines the timing of outputting the shutter "open" signal, the timing of inputting the shutter "close" signal, the timing of outputting the forced end signal (shake limit time), and modes such as "frontlight" and "backlight". It calculates up/down of the gain (details will be shown later) and outputs it to the video processing control circuit 25.

28 is a communication line between the system controller 10 and the system controller 23;
For example, switch information signals such as SL, S2, date, playback, field/frame, slide copier, negative copier, write or write prohibition, floppy detection, etc. and control signals such as spindle motor ON/OFF, current track number, etc. will be sent.

Next, the photometry mode classification of subject brightness based on photometry information will be explained using Table 1. As shown in the same table, the metering mode for subject brightness is divided into ``Bright'' mode, which allows you to shoot using only natural light, and ``Dark'' mode, which requires supplementary light from a flash. For each case of "Dark", there is a case of "Front light" where the brightness of the main subject on the shooting screen and the brightness of the sub-subject in the background is properly balanced, and a case of "Front light" where the brightness of the main subject on the shooting screen is relative to the brightness of the sub-subject in the background. It can be divided into four types: ``backlight'' on a sunny day; Note that ``Front light J includes reverse light.

In addition, for each of the four types of metering modes mentioned above, there is an "auto mode" that automatically determines whether or not the flash is necessary based on the metering results and selects the appropriate shooting method, and an "auto mode" that automatically determines whether or not the flash is necessary based on the metering results and selects the appropriate shooting method. There are three types of shooting modes: ``forced flash mode'', which lets the flash fire to take pictures, and ``flash prohibition mode'', which forcibly prohibits the flash from firing even when auxiliary light from the flash is required. handle. In addition, in the same table, "forced flash" and "flash inhibit" are respectively "forced flash mode" and "flash inhibit mode".
"Flash" indicates the shooting mode selected by "AE (flash off)" indicates "Auto mode."

By the way, if we classify the shooting methods in the above shooting modes based on whether or not a flash is required, there are two types: "Natural light mode", which uses only natural light without using the flash, and "Natural light mode", which uses only natural light without using the flash, and "Natural light mode", which uses the flash and uses both natural light and flash light. It is divided into "flash mode" for taking pictures. In the classification of photometry modes in Table 1 (described later), "Flash Prohibition J and rAE (Flash Prohibition)" are "Natural Light Mode J," and "Forced Flash" and "Flash" are "Flash Mode."

Next, the photographing method of the photographing mode for each photometry mode of this embodiment will be explained.

(1) About "Natural Light Mode": In this mode, when shooting in "flash off mode" in the case of "bright backlight", the brightness of the sub-subject is relatively bright compared to the brightness of the main subject. Therefore, if the main subject is photographed with an appropriate exposure amount, the secondary subject in the background will be photographed with brightness. For this reason, the photometered brightness of the main subject is corrected by +0°5Ev, and when the main subject is properly exposed, the exposure is stopped. By shooting in this way, the main subject will be exposed 0.5 times below the proper exposure.
Although the image is taken with a low Ev, the background is suppressed from being photographed too brightly at one end, and the image is taken beautifully as a whole.

Next, when shooting in "flash off mode" in the case of "dark backlight", the brightness of the secondary subject is relatively brighter than the brightness of the main subject, but the brightness of the secondary subject in the background is dark, so the main subject Even if the subject is photographed with the correct exposure, the secondary subject in the background will not be photographed excessively brightly.For this reason, the metered brightness of the main subject is not corrected and the main subject is taken with the correct exposure. Being photographed.

In addition, when shooting in "Flash off mode" in "dark front light" and "bright front light" with rAE (Flash off), the balance between the brightness of the main subject and the brightness of the sub-subject is relatively appropriate. In this case, the brightness of the entire shooting screen is bright and dark, so the average brightness (Bvs') is calculated by taking into account both the brightness of the main subject and the brightness of the sub-subject, and calculating the weighted average of each brightness. The image is taken so that the average brightness is the appropriate exposure. Note that when the brightness of the entire photographic screen is extremely low according to the limit value of photometry, the average brightness is set so that the weight of the brightness of the sub-subject is increased relative to the brightness of the main object. Additionally, if the brightness of the shooting screen is significantly below the photometry limit, the release will be locked and the camera will not be able to take pictures.

(2) About "Flash Mode J": In this mode, in "forced flash mode", it is thought that the photographer's intention was to use the flash light source regardless of the brightness of the main subject, so the metering Regardless of the mode classification, the flash is emitted by the shutter "open" control signal, and the main subject is photographed with proper exposure.

In addition, in the case of "bright backlight" (hereinafter referred to as "backlight flash mode j"), the luminance of the metered subject is -1.
, OEv correction is applied to calculate the appropriate exposure time for the sub-subject, and if the APEX value of the exposure time obtained by subtracting the above correction value 1°OEv is Tv, then after the start of shooting, expose with natural light until the above exposure time Tv. After that, the flash is fired and when the main subject becomes suitable, the exposure is stopped and the photograph is taken.

That is, the background is photographed using natural light with IEv brighter than appropriate, and then the main subject is photographed appropriately using flash light. By photographing in this manner, the main subject can be photographed clearly, and the sub-subject can be photographed brightly relative to the main subject, creating an atmosphere of backlight.

In addition, in the case of "dark backlight" and "dark forward light" (hereinafter referred to as "dark flash mode"), the metered brightness of the main subject is ±1. Apply the OEv correction, calculate the appropriate exposure time for the main subject, and set the above correction value 1. When the APEX value of the exposure time including OEv is `rv, after starting shooting, expose with natural light until the above exposure time] ゛v, then fire the flash and stop the exposure when the main subject becomes suitable. Take pictures like this. That is, the main subject is photographed using natural light IEv darker than appropriate, and then the main subject is photographed appropriately using flash light.

By the way, in the above embodiment, the exposure time corresponding to the flash emission timing time is divided into "backlight flash mode" and "dark flash mode" and calculated by the system controller 10, and the exposure time is calculated at the same time as the solid-state image sensor 9 starts exposure. However, instead of calculating the flash firing timing time from advance photometry information, the solid-state image sensor 9 is used to measure the secondary subject in "backlight flash mode" and the main subject in "dark flash mode". It is also possible to perform tie-left photometry at the same time as the exposure to obtain the flash firing timing. That is,
In the "backlight flash mode", the sub-subject brightness is directly measured at the same time as the exposure of the solid-state image sensor 9 starts, and 1. When OEv increases, fire the flash,
Exposure ends when the main subject becomes suitable. Also,
In the "dark flash mode", the brightness of the main subject is directly measured at the same time as the exposure of the solid-state FFL image element 9 starts,
1. The flash may be emitted when the OEv is low, and the exposure may be ended when the main subject becomes suitable.

This concludes the explanation of how to shoot in each shooting mode, and next,
A description will be given of dividing the photographing mode into modes based on the brightness of the subject detected by the photometric sensor 17.

The photometric sensor 17 is composed of two types of photometric sensors: a photometric sensor 17a that spot-meters the brightness at the center of the photographic screen, and a photometric sensor 17b that measures the brightness around the photographic screen. For example, when photographing a person, the main subject, the person, is often placed in the center of the shooting screen, and the background, which is the sub-subject, is often placed around the periphery of the shooting screen. This method measures the brightness and the brightness of the sub-subject separately.

By the way, the brightness at the center of the photographic screen measured by the photometric sensor 17a (hereinafter referred to as center brightness) is Bvl,
If the brightness around the shooting screen measured by the photometric sensor 17b (hereinafter referred to as peripheral brightness) is Bv2, the brightness of the main subject is Bvs, and the brightness of the sub-subject is Bv^, then the photometric value Bv2 is the same as the background. It can be used as the brightness Bv^ of the sub-subject, but it is known that using the photometric value Bv1 as the brightness BVS of the main subject will cause an error. For example, if the main subject is small in size relative to the shooting screen Moreover, when the subject is backlit, the background light wraps around the main subject, and the photometric value Bv1 becomes larger than the main subject brightness Bvs. Also, if the photographic lens is a zoom lens, the size of the main subject relative to the tit screen is changed by zooming. If you change the ratio arbitrarily, the photometric value Bv1 will change according to the ratio.
and the error in the main subject brightness Bvs will be different. Therefore, it is necessary to correct the photometric value Bvl to obtain the main subject brightness Bvs according to the ratio of the size of the main subject to the photographic screen and the difference in brightness between the main subject and the sub-subject. That is, if this correction amount is α, the main subject brightness Bvs is expressed as Bvs=Bvl −a =−■. Note that the unit of subject brightness is expressed in EV[.

Table 2 (described later) is an α map representing the correction amount α. In the same table, β is the photographing magnification that indicates the size of the subject relative to the photographic screen, and ΔBv is the difference between the peripheral brightness Bv2 and the central brightness Bvl, that is, ΔBv=Bv2−Bvl
It shows. As shown in the table, as β becomes smaller, the ratio of the size of the main subject to the shooting screen becomes smaller, and the amount of light that wraps around from surrounding objects to the photometric sensor 17a increases, so the value of the correction amount α becomes larger. It has become.

Furthermore, as ΔBv increases, the brightness of surrounding objects will be brighter than the main object, and the backlight will become stronger. This will increase the amount of light that goes around from the surrounding objects to the photometric sensor 17a, and the value of the correction amount α will increase. There is. However, when β is smaller than 1/100, the ratio of the size of the main subject to the shooting screen is so small that it cannot be considered as the main subject on the shooting screen, so do not include the correction amount α. There is.

Also, when ΔBv is 2.75 or more, a
! Since it can be considered that the amount of light that wraps around to the II optical sensor 17a is small, that is, the main subject is relatively accurately illuminated by α1 light in strong backlight, and it is also considered that the main subject is a relatively large object. Therefore, in order to take advantage of the photographing conditions, the value of the correction amount α is set small.

Here, the above main subject brightness Bvs and sub-subject brightness Bv
The mode classification by A into "frontlight J" and "backlight" will be explained.

The brightness difference (B
vA - Bvs ) is ΔBv', if the sub-subject brightness is larger than the main subject brightness by a certain value (δ), that is, if ΔBv'>δ, then the sub-subject is higher than the main subject. Set it as “backlight” which is too bright, and set ΔBv′≦
In the case of δ, it is assumed that the brightness of the main subject and the sub-subject is well-balanced, ie, "front light".

Table 3 (fk) is a δ-manp that provides the above-mentioned constant value δ. The δ values in the table were determined through actual photography, and the δ values vary in three levels depending on the brightness of the main subject. This is because as the brightness increases, the amount of light that wraps around from the periphery to the center increases, making it difficult to detect backlight, and the constants in Table 3 are selected to accommodate this.

Next, the classification of flash emission modes will be explained.

Exposure time is long, and the brightness is at the limit where photographers can experience camera shake (
Let BvH be the camera shake limit brightness (hereinafter referred to as camera shake limit brightness), and when the overall brightness of the photographing screen is lower than the camera shake limit brightness BvH, a "flash mode" is set in which a flash is emitted to take a picture.

By the way, as for the overall brightness of the shooting screen, since the main subject brightness and the sub-subject brightness are different, the weighted average ff1BVs' of the main subject brightness Bvs and the sub-subject brightness BvA taking into account the respective brightnesses is calculated as the average brightness of the entire shooting screen. It will be used as ``In the case of front light j, Bvs' is given by Bvs' - Bvs/4 + (3-BvA )/4, and when Bvs'≧BvH, it is called ``frontlight flash mode'', and when Bvs'<BvH, Since the entire shooting screen is dark, select [Set dark flash mode J].

In addition, ``In the case of backlight J, the sub-subject brightness is higher than the main subject brightness, so the value obtained by subtracting δ from the sub-subject brightness Bv^ (BvA-
δ) will be used.

That is, when BvA-δ≧BvH, the background is bright,
Since the main subject is dark due to backlighting, we set the flash to "backlight flash mode" and set BvA-δ<Bv
When H, since Bvs≦BvA-δ<BvH, the entire photographing screen is dark even though it is backlit, so it is set as the "dark flash mode".

In addition, if the center brightness Bv1 is low enough to be the limit value for photometry by the photometry sensor 17a, the reliability of the photometry value is low, so whether the main subject brightness Bv Weighted average value Bvs with increased weight
” to process as “low brightness processing mode”. That is, Bvs' = Bvs/80 (7-BvA)/
Using Bvs' calculated in step 8, processing is performed as [dark flash mode].

"Natural light mode", "Dark flash mode J" are shown below.
, "backlight flash mode", and "forced flash mode", the control of the exposure time of the solid-state image sensor 9 and the control of the flash light emission timing time will be explained.

FIG. 3 shows an example of the exposure time of the solid-state image sensor 9 and the timing time of flash emission. Same T v t
l In the figure, tl+ (=2) is the limit exposure time that causes camera shake (camera shake limit shutter speed), and is changed according to the output of the zoom encoder, that is, the value of the focal length f of the lens.

tH (=2-Tvx) is the highest shutter speed that can control the exposure time of the solid-state image sensor 9, and to is the above tH by 2
It shows the time after division j7. Further, Tv LA (=2) is the delay time from when the solid-state image sensor 9 starts exposure in response to a shutter start signal until when the flash starts emitting light, and in "flash mode",
After being exposed to natural light for a predetermined time tA, a flash is emitted. Further, tF indicates the time during which the flash is emitting light, and ts indicates the time at which proper exposure is achieved.

(1) “Natural light mode” will be explained.

The "natural light mode" is divided into three types of photographing methods, which will be explained below, depending on the brightness of the main subject.

■When the brightness of the main subject is very bright and the appropriate exposure is reached within the time of the maximum shutter speed tH.

Exposure is carried out up to the maximum shutter speed time tH, and overexposure is carried out beyond the time ts at which proper exposure is obtained (tH-ts), so that the captured image is reduced in gain by the image processing control circuit 25. Overexposure is corrected.

By the way, since the exposure time of tH/2 corresponds to overexposure of IEv, ts≦to (however, to=tH/2) and t
System controller 1 separately in the case of H>ts>to
0, the gain correction amount is changed and output to the video processing control circuit 25. That is, if ts≦to, the excessive exposure time (tH to S) will be shorter than tH/2, so a constant gain of 1. When OEv is decreased and tH>ts>to, the excessive exposure time (tH-ts) is longer than tH/2, so the constant gain of 0.5Ev is decreased.

■When proper exposure can be obtained in a time shorter than the camera shake limit shutter speed tH.

This is a case where proper photography is performed using only normal natural light.
The photographed video is recorded without exposure correction by the video processing control circuit 25.

■ Time ts when the brightness of the main subject is dark and reaches the appropriate exposure
exceeds the camera shake limit shutter speed t11.

Camera shake limit shutter speed tH to prevent camera shake
Exposure is forcibly stopped at , and the gain of the image photographed by the image processing control circuit 25 is increased by 0.5 Ev to correct the underexposure.

(2) Dark flash mode" will be explained.

In the "dark flash mode", after the solid-state image sensor 9 starts exposure, the main subject in the shooting screen is set to 1. O
Until the time when Ev reaches a low value (this time is defined as tA),
exposed by natural light, then a flash is fired,
Exposure is stopped when the main subject becomes suitable.

In this [dark flash mode], there are three types of shooting methods depending on the main subject, the melon. In other words, ■When the proper exposure is reached while the flash is firing.

■When the proper exposure is reached within the camera shake limit time t11 after the flash fires.

(2) When the time tS at which proper exposure is reached after the flash is fired exceeds the camera shake limit time tH (includes cases where the flash is fired at tA=tH and proper exposure cannot be obtained after the flash is fired).

In the case of (1) and (2) above, exposure is stopped when proper exposure is obtained, and the photographed image is recorded without exposure correction by the image processing control circuit 25. In the case of (3), when the camera shake limit time tH has elapsed, the exposure is forcibly stopped to prevent camera shake, and the underexposure is transferred to the video processing control circuit 2.
5, the gain is increased by 0.5Ev and corrected.

(3) “Backlight flash mode” will be explained.

In "backlight flash mode", the time from when the solid-state image sensor 9 starts exposure until the secondary subject in the background in the shooting screen has a value IEv higher than the appropriate exposure (this time is set as ta)
The subject is exposed to natural light until the main subject is properly exposed, then the flash is fired, and the exposure is stopped when the main subject is properly exposed.

In this "backlight flash mode", there are two types of shooting methods depending on the brightness of the subject. In other words, ■When the proper exposure is reached while the flash is firing.

■When the proper exposure is not reached even after the flash emission time tF has elapsed after the flash emission.

In the case of ■ above, stop the exposure when the proper exposure is obtained,
The photographed image is recorded without exposure correction by the video processing control circuit 25. In the case of (2), since the "backlight flash mode" is used to photograph a subject with a bright background, if the main subject is exposed beyond the flash emission time tF until the time ts when the main subject is properly exposed, the natural light after the flash emission will be Since the secondary subject becomes excessively bright due to exposure, the exposure is forcibly stopped after the flash emission time tF, and the image processing control circuit 25 for the captured image
No exposure correction is made.

Next, in the above-mentioned "backlight flash mode" and when the distance of the main subject exceeds the limit that the flash light can reach, the solid-state image sensor 9 starts exposure and the flash light emission delay time t^ described above is reached. The lens is exposed to natural light until a time in which 1° OEv is added (this time is set as t^'=tA/2), then the flash is emitted, and after the flash is emitted, the exposure is stopped. Similar to the above-mentioned [backlight flash mode], if the time ts at which the main subject is properly exposed or the flash emission time tF is exceeded, the exposure is forcibly stopped after the flash emission time tF, and the image processing control circuit 25 Set the gain to 1. Exposure is corrected by increasing OEv. In other words, in backlight flash mode J, where the distance At of the main subject exceeds the limit of flash light reach, the flash does not work effectively as auxiliary light for the main subject, so the exposure time using natural light is changed to the above-mentioned r backlight flash mode. The exposure time is shortened to half of the natural light exposure time in ``, and the overall IEv is darkened, and then the flash is fired and the exposure is forcibly stopped after the flash is finished, so that the overall image is This increases the gain by IEv. Then, in this way, the overall IEv is lowered so that the difference in brightness between the main subject and the sub-subject is smaller than the actual brightness difference, and the IEv is corrected to be higher overall at the video stage. Therefore, the main subject can be photographed clearly, and the brightness balance between the main subject and the sub-subject can also be appropriately adjusted. Here, the flash emission timing time tA is the time from the start of exposure of the solid-state image sensor 9 until the flash is emitted, and is calculated by the system controller 10 based on the photometered main and sub-object brightness. It is.

(4) “Forced light emission mode” will be explained.

In "forced flash mode," the flash fires when the maximum shutter speed tH has not elapsed after exposure starts, and the exposure stops when the main subject is properly exposed9.
In addition, if the time required for the main subject to be properly exposed exceeds the camera shake 1 range shutter speed tH, the camera shake limit shutter speed is set to prevent camera shake, and when 11 has elapsed, the exposure is forcibly stopped, and the exposure is The deficiency is corrected by increasing the gain of the image by 0.5 Ev in the video processing control circuit 25.

Next, a sequence for controlling the camera section of the system controller 10 in the electronic camera of this embodiment will be described.

First, the main routine will be explained using the flowchart shown in FIG. In the first state when the battery is inserted into the camera, the system controller 10 is reset to the initial state (#5), executes the initial setting subroutine,
Initial settings of the system controller 10 are performed (#1
0). Next, in steps #15 to #30, it is checked whether the camera is in the shooting state. In other words, check whether the power supply battery is turned on (#15), whether "playback mode" is selected with the playback switch sio (#20), whether the deck lid is open (#25), and whether the deck is young. Check at each step whether the state has changed from open to closed (#30). If the battery is not inserted in each of the above steps, a blue routine is executed to "remove the battery"(#200)."Playbackmode"
If has been selected, a "playback" subroutine is executed (#210). When the base of the deck is open, execute the subroutine ``Prohibit recording/playback J'' to prohibit both recording and playback operations (#220).A floppy disk for recording is inserted, and the deck lid is closed. ``Open J to ``close''
When the state changes, the "initial load" subroutine is executed, the information on the floppy disk is checked, and the information is loaded into the system controller 10 (#500).

Next, check whether the main switch SO is turned on (#35). If the main switch SO is OFF, shooting will not begin, so proceed to #110, set the photographing lens 1 to the initial position, and turn off the display on the LCD display circuit 21a (#115). If the flash circuit 18 is If the voltage is being increased for charging, proceed to #145, stop the voltage increase, and turn off the flash charging LED display (red) in the viewfinder (#150).
The state is entered (S160). Halt the execution of the sequence of the HALTALT state stem controller 10, and check whether there are any changes in the settings of the switch controller 21 at regular intervals (
In step S170), if there is no change in the settings, the process goes into a HALTALT state, and if there is a change in the settings, the process returns to #15.

When the main switch SO is turned on, the same switch S
Check whether O has changed from OFF to ON (#40
), when the main switch SO is turned ON for the first time, the "boost required J" is activated to charge the flash circuit 18.
If the flag is not set to ON for the first time, S45 is skipped and the display is performed on the LCD display circuit 21a (S50). The LCD display circuit 21a displays field/frame and single/self-timer mode selection, a counter for the number of shots, a battery warning, a recording mode, etc.

Next, check whether the AE and AF start switch S1 is turned on (S55). If the switch S1 is turned on, it does not indicate that the switch S1 is kept pressed.
The presence or absence of the "Keep pressing" flag is confirmed (S60). This will perform AE and AF again when switch S1 is pressed again, and if switch S1 is held down, new A
E. This is because AF is not performed. If this flag is not set, execute the "Sl" subroutine and
Perform E (auto exposure) and AP (auto focus) (S80
0). Switch S1 is OFF or “
If the "keep pushing" flag is set, then it is checked whether there is a change in each mode of single/self-timer, field/frame, and date information switching (S65).

That is, single/self-timer mode changeover switch S15, field/frame mode changeover switch S1
1. When none of the date information mode switching switches 55-1 are kept pressed, switch S15.
311.55-1 is checked in order to confirm whether there is a mode change.
If N, the "mode change" subroutine of S230 is executed. If the date changeover switch 55-2 is ON in S75, the "date change" subroutine of S240 is executed. If the field/frame mode change switch S11 is ON in S80, execute the [Field/Frame change] subroutine in S250, and if each mode is not changed, check whether the date is corrected (S85). ). If any switch is kept pressed, there is no mode change, so the process proceeds to date correction (S85) without checking each mode changeover switch (skipping #70 to #80). If the date correction switch 55-2 is pressed, the "date correction" subroutine of S260 is executed. If the date information is not corrected, next check whether flashing is necessary (#90 to #1
05), this is to set a flag in order to identify whether or not boosting the voltage for charging the flash circuit 18 is necessary depending on whether or not flash is necessary. If the "forced light emission" switch S13 is pressed in S90, the "boosting required" flag is set in step S95), and the "light emission prohibited" is set in #100.
If the switch S14 is pressed, a "boosting unnecessary" flag is set (S105).

Next, check whether the "boost required" flag is set, and if it is set, start boosting if charging is not completed.
1 LED display in the viewfinder when the flash is charging b (
red) (#120 to #135). Then, the pressure increase time is confirmed (S140), and when the pressure increase is completed within a predetermined time, the process returns to #15. Here, if the boosting is not completed within the predetermined time, a battery check is performed (S270>. Also, check if the "boosting required" flag is not set in S120, or if charging has already been completed in S125. If so, the process proceeds to steps #145 to #170 described above and enters the H, ALT state.When each subroutine ends, the process returns to step S15(A).

Next, the "initial load" subroutine of S500 will be explained using FIG.

First, a battery check subroutine is executed to check the battery capacity (#505). Next, it is checked whether a floppy disk is inserted (#510), and if it is not inserted, the "release not allowed" subroutine of #700 is executed to prohibit driving of anything other than the mirror 3 and photographic rinser 1. If inserted, D C/D is used to supply power to the spindle motor 27 and video processing control circuit 25.
The C converter 12 is activated (#515).

Next, the spindle motor 27 and the video processing control circuit 25 are driven (#520), the contents written on the floppy disk 26, that is, the data of 50 tracks are read, and a map is created. In addition, the LCD display circuit 1
9b displays the track that is counting up, indicating that the contents of the floppy disk 26 are being confirmed (#525).

Next, check whether the "playback mode" is selected with the playback switch 510 (#530), and if the "playback mode" is selected, execute steps #535 to #545 to enter the "playback mode". In other words, check whether there is a recording prohibition claw on the floppy disk 26 (#535), and if there is no claw, recording will be prohibited, so set the "erasure prohibited" flag #540), and if there is a claw, recording will be allowed. Therefore [Eraseable J
The flag is set (#545), and the process proceeds to the subroutine of #210 "Next playback mode". If “playback mode” is not selected in #530, the floppy disk 26
Check whether there is a recording prohibition claw #550), and if there is no claw, display "recording prohibition" for the inserted floppy disk 26 on the LCD display circuit 19b #555).
Stop the recording operation (#570). Also, if there is a claw, check whether there is an empty track on the floppy disk 26 (#560), and if there is no empty track, display the fact that there is no empty track on the LCD display circuit 19b (#56).
5) Stop the recording operation in the same way as without claws (#
570). If there is an empty track, the program proceeds to #600, moves the head to an unrecorded track based on the map information obtained in #525, and then returns to #15 of the main routine.

Next, “Sl” of #800 executes AE and AF etc.
The subroutine will be explained using FIG. “S.
1'' subroutine sequence executes AP, executes AE after focusing on the subject, prepares the flash to emit light if necessary, and enters release. First, #805 to #835 before entering the AP
Check the pantry, power supply, system controller 23
, white balance, etc. In other words, when boosting the voltage of the flash circuit 18, stop the boost (#805) and perform a battery check (#81).
0), to set the white balance (WB) to a specific color temperature for daylight #815), and to supply power to the solid-state image sensor 9, video processing control circuit 25, spindle motor 27, and other circuits. Activate the DC/DC converter (#820) and start the system controller 2.
3 (Reset CPU2>#825) and start the color temperature sensor circuit 20 (#&30).

Next, execute the AP subroutine #1200 (described later), perform a focusing operation on the subject (#835), and if the reliability of the focus detection result is low due to low contrast and the focus is incomplete, , displays out-of-focus in the viewfinder,
Return to main routine #15 (#840 to #850)
. When focusing is completed in #840, check whether the self-timer mode is selected (#855); if the self-timer mode is not selected, start the spindle motor 27 to drive the floppy disk 26. and prepares for recording (#860). If the self-timer mode is selected, there is no need to drive the spindle motor during the time until release, so #860 is skipped and the color temperature information of the light source is determined from the color measurement information of the subject by the color temperature sensor circuit 20. (#865) and detect whether the light source is a fluorescent light or tungsten light (#87
0). When the light source is a fluorescent lamp or tungsten light, a "flash required" flag is set in order to emit a flash and tMu (#875).

This is because fluorescent lamps or tungsten light have a different color temperature distribution than sunlight, and it is better to take pictures with flash light that is similar to sunlight, so the flash is automatically fired. When the light source is not a fluorescent lamp or tungsten light, the "photometering" subroutine of #1500, which will be described later, is executed without setting the "flash required" flag to measure the brightness of the subject (#880).

Next, when the metering of the subject brightness is completed in #880, #88
In steps 5 to #905, various flags are checked to confirm whether or not a flash is necessary. First, check if the flag is set.
Alternatively, if the flag is not set but the "forced light emission mode" is selected (#890), then it is checked whether the "light emission prohibition mode J" is selected (#895).

[If flash prohibition mode J is not selected, it is in flash mode, so check that #890 "Forced flash mode" is selected #905) If it is selected, set the "Forced flash mode" flag. Set it (#910
m Check the charging state of the flash circuit 18 (#9
15). The reason why the "forced flash mode" flag is set in #910 is to identify the fact that the flash light emission timing is different between "forced flash" and auto mode.

Next, if charging of the flash circuit 18 is completed in #915, stop boosting the voltage for charging (#920), #8
If the spindle motor 27 has not been started at step 60, the spindle motor 27 is started, preparations are made for recording onto the floppy disk 26 (#925), and the LED display 19a (green) indicates that the flash has been charged in the viewfinder. (#93
0), proceed to #970 and check the release switch S2. If charging of the flash circuit 18 is not completed in #915, start boosting the voltage for charging #935),
If the spindle motor 27 has been started in #860, its drive is stopped (#940), and the LED display 19a (red) indicating that the flash is being charged is displayed in the viewfinder (#945).
). The reason why the spindle motor 27 is stopped in step #940 is to avoid unnecessary current consumption since it is not necessary to drive the spindle motor 27 during preparation for flash emission.

Next, check the state of switch S1 (#950),
If it is 0FFt, return to #15 of the main routine,
If it is ON, check switch S2 #955
), if switch S2 is ON, the process returns to #15 of the main routine, and the LE in the viewfinder that is charging the flash
Turn off the D display 19a (red) (#965) and proceed to #920 to #930 described above.

By the way, if "forced flash mode" is not selected in #890, the flash will not fire, so just press #
Proceed to step 970 and check the release switch S2.Also, since the flash will not fire even when "flash prohibition mode" is selected in #895, the flash will not fire in priority over "forced flash" or auto mode. #8
Change the color temperature for daylight set in #15 to #865
Based on the input colorimetric information, the temperature sensor circuit 20 changes the signal to a signal for adjusting the color balance of the photographed image and outputs it (#900>, proceed to #970).

Next, check the release switch S2 (#970), and if the switch S2 is OFF, the switches so and s
t is confirmed (#1030 to #1035), and if any of them is OFF, the process returns to #15 of the main routine. If either switch 5O1S1 is ON, check whether the deck lid is open or closed (#1040); if the deck lid is closed, return to #865; if it is open, check #22
Executes subroutine 0 and prohibits all recording and playback operations.

If release switch S2 is turned on in #970,
Make sure the self-timer mode is selected #9
75) If the self-timer mode is selected, the timing time for self-timer photography is counted, the light emitting element 14 is blinked (#980), and the spindle motor 27 is activated.
, prepare for recording to the floppy disk 26 (#985), and after Looms has passed, flip up the main mirror 3 and release the light shielding to the solid-state image sensor 9 (#99
0), if the self-timer mode is not selected,
Skip #980 to #985 above and main mirror 3
Upload the solid-state image sensor and image processing control port 1 to 32.
5 (#995). The power supply rise time of the video processing control circuit 25 (approximately 100 ms)
After counting (#1000), #2000 (described later)
The "release" subroutine is executed and the solid-state image sensor 9 is exposed (#1005). Next, the solid-state image sensor 9 is exposed.
After the exposure is completed, record the photographed image on the floppy disk 26 (#1010), stop driving the color temperature sensor circuit 20, video processing control circuit 25, and solid-state image sensor 9 (#1015), and close the main mirror 3. Lower it (#102
0), execute the "head feed" subroutine (designates the next track based on map information) #1025)
, return to #15 of the main routine.

As explained above, in this embodiment, in the "Sl" subroutine sequence, in order to accurately measure the brightness of the main subject and the brightness of the sub-subject, AF is executed first and the subject is accurately focused. The calculation of photometry (AE>) is executed later.

By doing this, in the "photometry" subroutine sequence described later based on accurate photometry data,
It is possible to classify appropriate photometry modes and calculate accurate flash firing timing. Also, in self-timer mode, to avoid unnecessary current consumption,
The spindle motor 27 is not activated until a predetermined period of time has elapsed. In addition, when using fluorescent light or tungsten light as the light source, the color temperature setting is fixed to sunlight (flash light source), so the flash is automatically emitted to take a picture, and the flash prohibition switch S14 is set. When "Light off mode" is selected, the color temperature is automatically set to the color temperature of fluorescent light or tungsten light (AWB).
I try to do that.

Next, the rAFJ subroutine of #1200 <#835 above) for executing the AP will be explained using FIG.

First, turn on the power to the focus detection sensor 7 (COD line sensor) (#1205), then drain the unnecessary charge accumulated in the focus detection sensor and set it to the initial state (#1
210), start charge accumulation of the focus detection sensor (#1
215). After that, wait until the input signal lNTl indicating the end time of charge accumulation of the focus detection sensor is input (#1220), and wait until the interwoven signal lNTl is input.
When detected (#1225), the accumulated charges of the focus detection sensor 7 are transferred to the analog shift register, and the accumulated charges are output from the shift register one pixel at a time, A/D converted, and sequentially input to the system controller IO ( #123
0).

Next, the system controller 10 detects the defocus ID from the collected data #1235) and determines the reliability of the defocus measurement #1240>.
If it is unreliable due to low contrast,
Execute the "low contrast" processing subroutine #
1325), an out-of-focus display is performed (#1330), and the process returns to the main routine (#1320). If the subject is not unreliable due to low contrast, check whether the subject is accurately focused (#1245).・Find the current stop position information from the information, use the conversion coefficient according to the focal length f at that time to find the shooting distance based on this information, and calculate the shooting distance and focal length 1lf.
The photographing magnification β is calculated from f (#1305), and the in-focus LED 19a (green) is displayed in the viewfinder (#1310), the clutch circuit 13 is turned off, and the connection to the motor M is connected to the photographing lens. 1 to main mirror 3 (#1315) and return to the main routine (#1
320), and if it is not in focus in #1245, it will be focused in the following steps.

First, the lens extension amount conversion coefficient K is read from the ROM in the system controller 10 based on the current focal length f from the zoom encoder switch 312 (#125
0), the number of pulses N (= K
xD) (#1255), then put the calculated number of pulses N into the counter J in the system controller that monitors the motor rotation amount (#1260), and calculate the clutch number F.
N113 is turned on, the connection to the motor is switched from the main mirror 3 to the photographing lens 1 (#1265), and driving of the photographing lens 1 is started (#1270).

Next, make it possible to interrupt by [Counter]#
1275), wait until the counter value = 0 and a counter interrupt occurs #1280), and with the counter interrupt occurring (#1285), take the photographing lens 1.
Stop driving and focus (#1290). Then, in order to confirm the in-focus state, charge accumulation in the focus detection sensor 7 is started again.
Wait until 1 is input (#1300), and then enter #
Return to #1225 and perform focus confirmation processing. 0 If focus is incomplete during focus confirmation processing, go back to #1245 to #12.
Go to step 50 and repeat the routine from #1250 to #1300 until focus is achieved.

Next, the "photometering" subroutine of #1500 (#880 above) will be explained using FIG. 8(a). In addition,
In the figure, the unit used for calculation is the APEX value.

First, calculate the ISO sensitivity correction, that is, calculate the corrected ISO sensitivity 5v (=Svo+γ) from the standard ISO sensitivity 3vo of the solid-state image sensor 9 and the imaging sensitivity variation correction amount γ #1503), and then 17a and 17b, the photometry of the brightness Bv1 (spot photometry value) at the center of the shooting screen and the brightness Bv2 (average photometry Iif) around the shooting screen are started (#1505), and then the photometry sensor 1
7a and 17b to start converting the analog signal of the luminance measured by the double integration circuit 22g into a digital signal (#1510), and then confirm that the A/D conversion of the luminance measured by the photometer is completed #1515 ), if it is not completed, wait until it is completed, and when it is completed, input the photometric data converted into a digital signal to the system controller 10 (#1520).

Next, check whether AF-AE lock is completed (
#1525), if the AP-AE is not locked,
Execute steps #1530 to #1545 to obtain the brightness difference ΔBv between the peripheral brightness Bv2 and the center brightness Bv1 and the main subject brightness Bvs. In other words, check if Bvl is over 11.#
1530), if it exceeds 11, the center brightness is too high, so fix Bv1 = 11 #1535), if it is less than 11, use the same Bvl and calculate the brightness difference ΔBv between the peripheral brightness Bv2 and the center brightness Bv1 =Bv2-Bvl #1540), then subtract the correction amount α shown in Table 1 from the center brightness Bv1 to obtain the main subject brightness Bvs (-B
vl-α) is calculated (#1545). When AP-AE is locked, the brightness difference ΔBv and main subject brightness BvS have already been determined, so #1530 to #1
Skip 545 and proceed to #1550 described below.
After the switch S1 is closed in the main routine (#55), when AP-AE first enters the photometry (AE') calculation subroutine (# of subroutine "Sl"
880 to #1500), the lock is applied and the process proceeds from #1525 to #1530, where the subroutine "S
It is locked for the first time when it returns from #1040 to #865 of "l" and then returns to #1525 from #880.

Next, check if the peripheral brightness Bv2 is over 10.#
1550) If Bv2 exceeds 10, the peripheral brightness is too high, so Bv2 should be fixed at 10 #1555)
, 10 or less, Bv2 is used as it is and is set as the sub-subject brightness Bv^ (#1560). Next, the central brightness Bv
, 1, check whether the brightness is low to the photometric limit value of the photometric sensor 17a (#1565), and if the brightness is low to the photometric limit value, the average brightness B of the entire shooting screen for low brightness processing.
Calculate vS' using the following formula #1595), #1600
Proceed to. That is, Bvs 7 − Bv^Bvs' =
+If it is not low brightness, see Table 2 and B
Find the reference value δ for backlight judgment from vs (#1570), and then calculate the brightness difference Δ between the secondary subject brightness BvA and the main subject brightness Bvs.
Bv' (=Bv8-to vs) is compared with the criterion 4friδ obtained in #1570 (#1575). here,
If ΔBv'>δ, it is determined that there is backlight [Set the backlight J flag #1580], set the average brightness Bvs' for backlight processing to Bvs (#1590), and #16
If ΔBv'≦δ, it is determined that there is "frontlight", and the average brightness Bvs' for frontlight processing is calculated using the following equation (#1585), and the flow proceeds to #1600.

Bvs 3-BvA Bvs' = Next, classify the shooting mode in #1600 to #1615. First, check whether the "backlight" flag is set. If the #16001 flag is not set (
For "Front light mode"), #1585 or #1595
Compare the average brightness Bvs' of the entire shooting screen obtained with the camera shake limit brightness BvH, and divide the mode into "flash mode" and "natural light mode"(#1605),Bvs'
If ≧Bvll, then it is determined whether the flash necessity flag is set (#1606). Here, if the flag is set, it indicates that the illumination light source is not sunlight but artificial light such as a fluorescent lamp or tungsten light, and it was set in #875 in Figure 6.
“Proceed to Routine 2 of Dark Flash Mode J. Meanwhile,
If the flag is not set, proceed to #1620 of the "natural light mode" routine ■; if Bvs'<BvH, proceed to #16 of the "dark flash mode" routine ■
Proceed to 75. If the "backlight" flag is set (
In the case of "backlight"), compare the brightness (BvA-δ) obtained by subtracting the backlight judgment reference value δ from the sub-subject brightness BvA and the camera shake limit brightness Bvll (#1610), (BvA-δ)≧E
If it is ivH, a "bright and reverse" flag indicating backlight on a bright background is set (#1615), and the process proceeds to #1800 of routine (2) of the "backlight flash mode". ()3
If v^-δ)<BvH, it is backlighting in a dark background, so "Dark Flash Mode J Routine ■ #1
Proceed to 675.

Next, the "natural light mode" will be explained.

First, check whether the "forced flash" flag is set (#1620). If the flag is not set, then [Check whether the road J flag is set #1625), and if the "bright/reverse" flag is also not set, the average brightness Bvs' is set in the control BvriBv■ Set the correction amount ΔEvH to O when directly metering the main subject brightness (#1635).
). If the "bright and reverse" flag is set in #1625, the background is bright and backlit, so the control Bv value Bv-T
The main subject brightness Bvs should be corrected by +0.5, that is, BvT = Bvs + 0.5 (#1640),
Set the above correction amount ΔEvtlL to (0, 5-a) (
#1645). Note that α is the correction amount shown in Table 1, and its value changes depending on the imaging magnification β.

Next, compare the control B v lii B v T and the minimum brightness Bv that can be photographed (#1650), BvT≦Bv
If it is L, the shooting screen is too dark, so set the "shooting not allowed" flag. #16601 Display that shooting is not allowed in the viewfinder (#1665), and execute the "release lock" subroutine to prohibit shooting. (#1670),
If BvT > BvL, set the flash unnecessary flag (#1655) and return to the main routine (#1795).

Further, if the "forced light emission" flag is set in #1620, it is the flash mode, and the process proceeds to #1675 of the "dark flash mode" routine (2).

Next, the "dark flash mode" routine (3) will be explained.

First, check whether the "Flash Prohibition" flag is set (#1675). If the flag is set, proceed to #1625 of the "Natural Light Mode" Routine ■ even though you are shooting in natural light. The flag is set. If not,
Brightness with main subject brightness Bvs corrected by +1.0 (Bvs+
1) and camera shake limit brightness Bv)l #1680
), the setting of the control Bv value is switched depending on the brightness of the main subject. In other words, if Bvs+1≧BvH, the brightness (Bvs+1) obtained by correcting the main subject brightness Bvs by +1°0 should be set as the control Bv value BvT.
If vs+1<Bv)l, the main subject brightness is lower than the camera shake limit brightness, so the control Bv value BvT is fixed at the camera shake limit brightness BvH (#1690).

Next, the correction amount ΔEvF of the exposure amount due to flash emission
Assuming that the coefficient K added to L is 0 (#1695), the value of the photographing magnification β is classified into three types (#1700), and the correction amount ΔE of the exposure amount due to flash emission is calculated for each of them.
Set VFL (#1705 to #1715), that is, if β>(1/25), set the correction amount ΔEvF to 0 (#1705), (1/25)≧β>(11
55), the correction amount ΔEvF is <0.5-K)
#1710), if (1155)≧β,
The correction amount ΔEvFL of the exposure amount due to flash emission is (1
, 0-K) (#1715). This is to correct the fact that the size of the main subject on the photographic screen changes depending on the imaging magnification β, and the amount of exposure due to flash emission also changes.

Next, the above correction amount ΔE is added to the maximum light emission amount Iv of the flash.
Flash light emission amount 1v (-1v+Δ
EvFL), and then calculate the aperture value A using the following formula from the above Iv', film sensitivity Sv, and subject distance information Dv.
Calculate vD (#1720). That is, AvD = I v' + 5v - Dv = I v + 5v - Dv + ΔEvF Next, compare the aperture value AvD obtained in #1720 with the aperture value Avoz corresponding to the focal length at that time, and calculate the subject distance A.
Determine whether the color exceeds the reachable limit of the flash light (#1725). If AvO>Avoz, issue a "remote" warning indicating that the distance of the subject exceeds the reachable limit of the flash light. (#1730), further set the "remote" flag (#1735), and set the aperture value Av.
Set D to Avoz (#1740), AvD≦Av
oz, do nothing and change the aperture value AvD.
is set to Avoz (#1740).

Next, the brightness BvH (=TvH+AvD -9v) calculated from the aperture value Avd obtained from #1740, the maximum shutter speed TvH, and the film sensitivity Sv and #1685
Or control set in #1690 B v fi B
If BvT≦BvH, proceed directly to #1765 and set the above control Bv value B.
The flash light emission timing time Tv is calculated using vT. If BvT>BvH, check whether the "road" flag is set (#1750); if the flag is not set, proceed to #1765; if the flag is set, control B v @ B v T (Tv
H+AvD Sv>(#1755), the main subject brightness Bvs and the control Bv value Bv obtained in #1755
Compare with T (=TvH+AvO-3v) #17
60), if Bvs≦BvT, proceed to #1765,
The flash light emission timing time Tv is calculated using the control Bv value BvT set in #1755. Also, Bv
If s>BvT, "Natural light mode Cortin ■ #
Proceed to 1620. In addition, in #1765, the flash emission timing time Tv is calculated from the following equation.

Ev=BvTMo5v Tv=Ev-AvD =BvT +5v-AvD Next, compare the flash timing time Tv calculated in #1765 with the maximum shutter speed TvH or camera shake limit shutter speed TvH. #1770.
#1780), if Tv≧'T” v H, it is the time when flash emission cannot be controlled, so set the timing time Tv to the maximum shutter speed TvH (#1780).
1775), if Tv≦TvH, there is a risk of camera shake occurring before the flash fires, so the timing time Tv is set to the camera shake limit shutter speed TvH.
(#1785), set the "flush required" flag #1790), and return to the main routine (#1795), TvH<Tv<TvH
If so (#1770, #1780), use the Tv obtained in #1765 and proceed to #1790 to #1795.

Next, the routine ③ of backlight flash mode J will be explained.

First, check whether the "light emission prohibition" flag is set (#1800), and if the flag is set, proceed to #1625 of the "natural light mode" routine (2). If the "flash prohibition" flag is not set, control 91B
v value B v T from sub-subject brightness BvA by correction amount 1
．． To the value minus OEv, that is, BvT = Bv8-,
Please set it to 0 #1805), the above control B v @ B
The brightness difference between v T and main subject brightness BvS, that is, the brightness difference ΔEvN from the appropriate natural light component (=Bv
s-BvT) #1810), the above luminance difference Δ
EvN and -1°OEv (#1815), ΔE
If vN>1.0, ΔEvN is fixed to -1,0 and the control Bv value BvT is adjusted to the main subject brightness Bvs by a correction amount of 1,0.
Set the value added by Ev, that is, BvT = Bvs + 1.0, and if ΔEvN≦-1,0, #1805 and #
Set at 1810, vT = Bvs + 1.0 and ΔEv
Use N = Bvs-BvT.

Then, the correction amount ΔEvF of the exposure amount due to flash emission
Set the coefficient K added to L to the value of α #1825)
, proceed to #1700 above and perform the processing from #1700 described in Dark flash mode J.

By the way, in the "backlight flash mode", a predetermined timing time Tv for flash emission is calculated from the brightness of the sub-subject (however, when δ≦Bv≦2, the timing time for flash emission is calculated from the main subject brightness), and the exposure is After the start, the flash is emitted after a predetermined time Tv has elapsed, and the exposure is stopped when the main subject is properly exposed, thereby adjusting the balance of brightness between the main subject and the secondary subject in the background. In the embodiment, since the exposure is stopped when the main subject becomes suitable after emitting the flash, the main subject becomes suitable, but the sub-subject becomes overexposed by the flash emission time.

Therefore, the present invention is not limited to the above-mentioned embodiment, and a second embodiment will be described below, which can accurately adjust the balance of brightness between the main subject and the sub-subject. That is, a certain correction time X [seconds] is calculated from the brightness difference between the main subject and the sub-subject, and
The flash is emitted X [seconds] before v elapses.

The value obtained by converting the above predetermined time Tv into [seconds] is X',
If the timing time of flash emission is x' (seconds) after correcting the fixed time X from the same x'', then X = 2-TV
[Seconds] x'=x −x [Seconds] Tv , ·, X·=2 −x C seconds] X' is the timing time of flash emission.

FIG. 8(b) shows a second embodiment using the predetermined time period X' for flash emission in the above-mentioned "backlight flash mode".
This will be explained using a flowchart.

The flowchart in FIG. 8(b) is inserted between #1765 and #1770 in FIG. 8(a).

First, in #1765, the flash emission timing time Tv is set.
After being calculated, it is checked whether the "excursion" flag is set (#1895), and if it is not set, the process directly proceeds to #1770. If the flag is set,
A correction amount ΔEvF from the appropriate amount of flash light is calculated from the luminance difference ΔEvN from the appropriate amount of natural light using the following equation (#1900).

ΔEv N > ΔEvF=Iog2 (12 Next, the required flash emission amount 1v from the main subject distance
s is calculated from the following formula (#1905).

I vs=Avoz+Dv-3v Next, compare the flash light emission amount Ivs obtained in #1905 with the actual light emission amount Iv. #1910) Ivs≦Iv
If so, calculate the correction amount ΔEvF ' obtained from the distance information obtained from the main subject distance and the appropriate correction amount ΔEvF for the flash light amount from the following formula #1915), and calculate the correction amount ΔEvF from the table shown in Table 4. A correction time X corresponding to ' is determined (#1940).

ΔEvF ′=Ivs-1v+ΔEvF Mana, Ivs)
If it is Iv, then the light emission amount Ivs' (=I
vs+ΔEvF) (#1920), and the correction amount ΔEvF' is calculated from the difference between this light emission amount 1 vs' and the actual light emission Ji I v (#1925). That is, ΔEvF ′=Ivs′−Iv Next, check whether the above correction amount ΔEvF ′ is less than or equal to OEv (#1930), and if ΔEvF ′>O, ΔE
vF' should be set to 0 (#1935), ΔEvF'≦0
If so, using the same ΔEvF′, #194
0, and calculate the correction amount ΔEvF' from the table shown in Table 3.
Determine the correction time corresponding to

Next, from the X obtained in #1940 and the above predetermined time Tv, the flash emission timing time X' C is calculated using the following formula.
seconds] (#1945>.

x'-2"T' V-x Next, convert the flash emission timing time X [seconds] into Tv [Ev:] using the following formula, and proceed to #1770 (#
1950).

Tv=Iog2 (1/x') This completes the explanation of the second embodiment. Next, the "release" subroutine of #2000 (#1005 in FIG. 6) will be explained using FIG. 9.

The "release" subroutine is comprised of routines for "natural light mode,""flashmode," and "forced flash mode."

First, the switch SW1 is switched to designate the photometry sensor as the light receiving section 17a (spot photometry at the center of the TFA shadow screen) (#2005). This is to control the exposure of the solid-state image sensor 9 to be stopped when the main subject becomes appropriate, so that the sensor that performs photometry is set to spot photometry at the center of the photographic screen. Next, in #2010 and #2015, the shooting mode is divided into "natural light mode", "flash mode", and "forced flash mode". If the "forced flash" flag is set in #2010, the process proceeds to the "forced flash mode" routine in #2235 to #2275 (t&description), and #20
If the "Flash Required" flag is set in step 15, the process advances to the "Flash Mode" routine in #2090 to #2230 (described later); if the "Flash Required" flag is not set, the routine advances to the "Flash Mode" routine in #2020 to #2085. Proceed to "Natural Light Mode" routine.

When shooting in natural light mode (#2020), first, the ISO sensitivity is corrected by the main subject brightness correction value ΔEvH and the imaging sensitivity variation correction value γ (#2025), then timer Tl and timer T2 are set to R high. i/ ya□y 9 sh”
-t t H (= 2 ” vH) f) 2 division value t
o and camera shake limit shutter speed thvH (=2), and at the same time as starting the countdown, the exposure of the solid-state image sensor 9 is also started (#2030). Next, at time t.

It is confirmed whether the exposure amount of the solid-state image sensor 9 reaches an appropriate level by the time the period of time has elapsed. In other words, check that the timer 'I'' 1 = 0 (#2035), and if TI>O, the voltage value of the capacitor C of the circuit 22i that detects that the amount of charge storage WI of the solid-state image sensor 9 has become appropriate. (hereinafter referred to as the exposure voltage value) and the reference voltage value Vo (#2040),
If Vo<V, the charge accumulation amount has not reached the appropriate value, so return to #2035, check timer T1 again, and set Vo.
If ≧■, the amount of charge accumulation has reached the appropriate value, but the charge accumulation will be excessive until time tH, so set a flag to correct the gain of the captured image by -1 or 0 (
Steps #2045) and #2280 to #2290 close the shutter and set the gain correction value -1°0 to the video processing control circuit 2.
5 and return to the main routine.

If T1=O in #2035, timer T1 is set to
Start the countdown by starting from 1, and then time t.
It is confirmed whether the exposure amount of the solid-state image sensor 9 reaches an appropriate level by the time o elapses (#2250 to #2060). time to
If the solid-state image sensor 9 reaches the proper exposure before time elapses, charge accumulation will be excessive until time LH, so a flag is set to correct the gain of the captured image by -0.5 (#2045). , proceed to #2280-#2290,
Close the shutter, output the gain correction value -0, 5 to the video processing control circuit 25, and return to the main routine.
If the solid-state image sensor 9 does not reach the proper exposure by the time the time to has elapsed (T1=O in #2055), then the time tH
Check whether the solid-state image sensor 9 reaches proper exposure between ~tH (#2070, #2075>, that is, Vo≧V
If so (#2070), the solid-state image sensor 9 has reached the appropriate exposure, so the shutter is closed (#2280), and since there is no gain correction, the gain correction value O is imaged by the image processing control circuit 25.
<#2285>, and return to the main routine (#2290>. If Vo<V, check whether T2=O (time tH has passed) #2075>, T2=
If it is O, the exposure time of the solid-state image sensor 9 exceeds the camera shake limit time, so the charge accumulation of the solid-state image sensor 9 must be forcibly stopped. Set a flag to correct +0.5 (#2085), close the shutter (#2280), and output the gain correction value 10.5 to the video processing control circuit 25 (
#2285), return to the main routine (#22
90>.

Next, to explain the flash mode (#2090), similarly to the natural light mode, first, the D/A conversion circuit converts the main subject brightness correction value ΔEvFL and the ISO sensitivity Sv corrected by the imaging sensitivity variation correction value γ. 22h (#2095).

Next, check if the backlight J flag is set #2100), and if the flag is set, check #215
Proceed to ``Backlight'' flash mode shooting (described later) in 5 to #2230, and if it is not set, proceed to #2105 to #2230.
Perform normal flash mode photography in #2150. In normal flash mode photography, timer T1 and timer T2
In each case, the flash emission timing time is A (=2).
The camera shake limit shutter speed tH is set, the timers TI and T2 start counting down, and at the same time, the exposure of the solid-state image sensor 9 is started (#2105). Next, T
Exposure with natural light is performed until T1=O (time tA elapses), and when T1=0, the flash is emitted (#2110 to #2115), and at the same time, timer T3 is activated.
The flash emission time tF is set at , and a countdown is started (#2120). During flash emission (T3>O), compare the reference voltage value vO and the exposure voltage value V, and if Vo≧V (#2125 to #2130),
Since the solid-state image sensor 9 has reached the appropriate exposure, #2280~
Proceeding to #2290, the shutter is closed, and since there is no gain correction, a gain correction value of 0 is output to the video processing control circuit 25, and the process returns to the main routine.

Next, if Vo<V does not result in proper exposure during flash emission, the solid-state image sensor 9 will reach proper exposure before camera shake limit time tH elapses (T2=O) after flash emission (after time tF has elapsed). (#2135~$21
40), 3i! When normal exposure is reached, (#2140), #
Similar to 2130, the process proceeds to #2280 to #2290, closes the shutter, outputs the gain correction value O to the video processing control circuit 25 since there is no gain correction, and returns to the main routine. The camera shake limit time tH has elapsed (T2=0
), when the time t11 elapses, the charge accumulation in the solid-state image sensor 9 is forcibly stopped (#2145), and the gain of the photographed image is increased by +0.5 to correct the insufficient exposure. Set the flag to be corrected (#2
150>, proceeds to #2280 to #2290, closes the shutter, outputs the gain correction value +0.5 to the video processing control circuit 25, and returns to the main routine.

Next, the "backlight" flag is set for $2100, and when shooting in "backlight" flash mode, an additional "
Make sure the "Remote" flag is set #2155
), if the flag is not set, set the flash emission timing ta in timer T #21
60), when the flag is set, the flash emission timing time tA' (=tA/
2) is set (#2195), a countdown is started, and at the same time, exposure of the solid-state image sensor 9 is also started.

“If the far-range J flag is not set, when the flash emission timing time t^ has elapsed (#2165
), fires the flash (#2170), simultaneously sets timer T to flash firing time tf, starts countdown (#2175), and while flash fires (1゛〉0), solid state tR1 element If 9 is properly exposed (#2180, #2190), #2280 to #2
Proceeding to step 290, the shutter is closed, and since there is no gain correction, a gain correction value of 0 is output to the video processing control circuit 25, and the process returns to the main routine. If proper exposure is not obtained during flash firing, after flash firing (after time tF has elapsed), the charge accumulation in the solid-state imaging probe 9 will be forcibly stopped (#2185), and the gain correction flag of the captured image will be set. Close the shutter without setting it (#2280), and set the gain correction value 0 to the video processing control circuit 2 since there is no gain correction.
5 (#2285) and return to the main routine (#2290). In the "backlight flash mode" shooting in #2160 to #2185, the background is brightly backlit, so the exposure is forcibly stopped in #2185. However, gain correction is not performed on the captured video.

Even when the "remote" flag is set, the flash is emitted after the flash emission timing time has elapsed, and the solid-state image sensor 9 When the proper exposure is reached, the shutter is closed, and since there is no gain correction, the gain correction value O is output to the video processing control circuit 25, and the process returns to the main routine (2200 to #2220. #2
280~#2290). If proper exposure is not obtained during flash emission, the charge accumulation in the solid-state image sensor 9 is forcibly stopped after the flash emission #2145), and a flag is set to correct the gain of the captured image by +1.0 (#2145). #
2230), closes the shutter (#2280>, outputs the gain correction value +1.0 to the video processing control circuit 25 (#2
285), return to main routine (#2290
).

#2195 to #2230 "Remote""backlight flash mode J" exposure time using natural light is half of the time LA when shooting "backlight flash mode", so in #2225 the exposure is forcibly stopped. In this case, the gain correction for the captured video is +1°0.

Next, to explain the forced flash mode (82235), first, the main subject brightness correction value ΔEvF[ and the ISO sensitivity Sv corrected by the imaging sensitivity variation correction value γ are output to the D/A conversion circuit 22h ( #2240>.Next, the maximum shutter speed tM and camera shake limit shutter speed tH are set in the timer T1 and timer 1 and 2, respectively, and at the same time as the timers T1 and T2 start counting down, the exposure of the solid-state image sensor 9 is also started. (#2245
)0 Next, when the maximum shutter speed tH has elapsed (
TI=O), use the flash #2250~#22
55), camera shake limit time tH has elapsed (T2=O)
Check whether the solid-state image sensor 9 reaches the appropriate exposure by (
#2260 to #2265). If the proper exposure is reached before the camera shake limit time tH elapses, the shutter is closed (#2
280), since there is no gain correction, the gain correction value O is output to the video processing control circuit 25 (#2285), and the process returns to the main routine (#2290). If the proper exposure is not reached, the camera shake limit time th has elapsed. When (T2=
0), forcefully stop the charge accumulation in the solid-state imaging element 9 #2270), and set a flag to correct the gain of the captured image by 10.5 to compensate for the underexposure #2275) , close the shutter (#2280), output the gain correction value 10.5 to the video processing control circuit 25 (#2285), and return to the main routine (#2285).
2290).

This concludes the explanation of the release sequence operation.

In this embodiment, in order to downsize and reduce the cost of the device, the flash light emission stop circuit is omitted so that the flash always emits full light.

but, To save power, turn off the flash when the exposure is stopped. table The light emission may also be stopped.

(below, margin) note) [Main]: Main subject brightness.

Bvs’ : Average brightness value of the shooting screen No. table note) tf, flash duration No. table

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an optical system of an electronic camera according to an embodiment of the present invention, FIG. 2 is a system configuration diagram of the electronic camera, and FIG. 3 is a time diagram for explaining exposure time and flash emission timing. Figure 1 is a flowchart of the main program for controlling the camera section of the electronic camera, Figure 5 is a flowchart for executing the initial load applied to the main program, and Figure 6 is a flowchart for executing the initial load applied to the main program.
The figure is a flowchart that is executed when the switch S1 applied to the main program is turned on, FIG. 7 is a flowchart for executing the AP that is applied to the flowchart of S1, and FIG. 8(a) is the FIG. 8(b) is a flowchart for explaining the second embodiment of the flash emission timing according to the present invention; FIG. 9 is a flowchart for executing the photometric AE calculation applied to the flowchart; 3 is a flowchart for executing a release applied to the flowchart. 6... Photometry sensor, 9... Solid-state imaging device (imaging means) 10... System controller, 18... Flash circuit, 20... Color temperature sensor circuit, 22...
Control IC123...System controller l-roller, 25.
...Video processing control circuit. Applicant Minolta Camera Co., Ltd. Agent
Patent Attorney Yasushi Itatani Kazuo 1 Diagram

Claims (3)

[Claims] (1) An imaging means for capturing an image of a subject, a determining means for determining whether the subject can be photographed without using a flash, and a flash that fires a flash when the determining means determines that a flash is necessary. An electronic still camera equipped with a light emitting means, characterized in that the electronic still camera has an adjusting means for adjusting the color balance of the video signal from the imaging means, and the color balance adjusting means is fixed for daylight use. (2) The determination means has means for measuring the color temperature of the subject and outputting information regarding the temperature, and when the information regarding the color temperature deviates from the color temperature fixed for daylight, Claim 1, characterized in that the device determines that the device is not in a state where photography can be performed without using light.
Electronic still camera described. (3) The determining means has a means for measuring brightness information of the subject and outputting the information, and when this brightness information is lower than a predetermined brightness, it is determined that photography is not possible without using a flash light. 2. The electronic still camera according to claim 1, wherein the electronic still camera comprises: