JPH10333221A - Exposure controller for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sufficient apodizing effect, without using an apodization filter by timewisely changing a transmitted light quantity, during exposure. SOLUTION: A ROM 81 stores a change control curve where the opening speed of an aperture 7 is acceleratively increased, in a state where the change control curve corresponds to each shutter speed. A diaphragm control means 82 selects the change control curve corresponding to the shutter speed obtained by an exposure calculating means 73, to control the opening of the aperture 7, along the change control curve. Then, a flash control means 75 starts the emission of a flash lamp 36, to obtain a maximum light quantity, just before the exposure is completed, through the use of the obtained shutter speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure control device for a camera which can obtain a special photographic effect by changing the opening area of an aperture stop during exposure of a film, that is, while a shutter is open. Things.

[0002]

2. Description of the Related Art In order to properly expose a film, a camera generally includes an aperture stop for limiting the amount of light that passes through a lens optical system and reaches the film, and a set exposure time (hereinafter referred to as "shutter speed"). ). A shutter for exposing the film by only opening it. The aperture area of the aperture stop and the shutter speed are factors that greatly affect the appearance of a photograph, and are closely related to blurring and blurring.

A lens shutter is a shutter provided in a lens optical system and generally configured as a combination of an aperture blade and a shutter blade, and also serves as an aperture stop and a shutter. For this reason, the aperture area and the shutter speed cannot be set independently of each other. Therefore, the aperture area and the shutter speed are determined according to the photometric value according to the specifications of the camera.

On the other hand, a single-lens reflex camera with interchangeable lenses generally has an aperture stop and a shutter formed separately, and has a focal plane shutter disposed immediately before the film as a shutter. In such a single-lens reflex camera, conventionally, the opening area of the aperture stop and the shutter speed are
It is set manually or automatically so that the film is suitably exposed according to the brightness of the subject. Then, at the time of photographing, first, the aperture stop is stopped down to a predetermined aperture value, and then the shutter is operated in a state where the aperture area is fixed.

A conventional lens shutter mode includes a lens shutter and a focal plane shutter, in which the lens shutter is operated as a program shutter, and a focal plane shutter in which the aperture is controlled by the lens shutter and the shutter speed is controlled by the focal plane shutter. A camera system in which a mode can be set has been proposed (see JP-A-1-316726).

According to this camera system, when the program exposure is performed by the lens shutter, the aperture area changes as time passes.
The motion direction of the moving object can be recognized from the blur of the image due to the aperture effect.

Conventionally, in the opening and closing operation of a lens shutter, an operation approximated to the case where an apodization filter is used (hereinafter referred to as "apodization") by operating with an exposure curve having a triangular waveform that opens at a relatively low speed and closes at a high speed. The camera has been commercialized to obtain the effect ("Photo Industry", Photo Industry Publishing Company, May 1971).
Monthly pp. 66-71). Apodization filters are
This filter is designed so that the transmittance decreases as the distance from the center of the optical axis increases in the direction perpendicular to the optical axis.When a photograph is taken using this apodization filter, the out-of-focus image is blurred as a whole and a good blur is obtained. The effect of giving an image of the condition is obtained.

[0008]

However, in the above-mentioned conventional single-lens reflex camera, the apodizing effect cannot be obtained because the aperture value is maintained at a constant value during exposure without changing.

Further, the above-mentioned conventional Japanese Patent Application Laid-Open No. 1-316726.
In the camera system described in the above publication and the camera operating with the above-described conventional triangular waveform exposure curve, the lens shutter opens at a constant speed as time passes, so that a sufficient apodizing effect or a desired apodizing according to the photographer's intention is performed. No effect can be obtained.

An object of the present invention is to solve the above-mentioned problem. An exposure control apparatus for a camera capable of obtaining a sufficient apodizing effect without using an apodization filter by temporally changing the amount of transmitted light during exposure. The purpose is to provide.

[0011]

SUMMARY OF THE INVENTION The present invention comprises an aperture stop for limiting the amount of light that passes through a lens optical system and reaches a film, and a shutter that exposes the film by opening the light-shielded state for an exposure time. In the camera, aperture control means for changing the opening area of the aperture stop while the shutter is open, and timing setting means for setting a light emission timing for emitting a flash while the shutter is open, A light emission control means for emitting a flash at a light emission timing (claim 1).

According to this configuration, the emission timing for emitting the flash while the shutter is open is set, the opening area of the aperture stop changes while the shutter is open, and the flash is emitted at the set emission timing. Emits light, the amount of light passing through the center of the lens optical system is different from the amount of light passing through the periphery, and an apodizing effect can be obtained even when the subject is dark.

[0013] In the exposure control apparatus for a camera according to the first aspect, the timing setting means sets the light emission timing immediately before the end of the exposure time.

According to this configuration, the flash emission timing is set immediately before the end of the exposure time, so that
The effect of the difference in the amount of light passing through the center and periphery of the lens optical system due to the change in the aperture area of the aperture stop during exposure remains on the film, and an apodizing effect can be obtained even when the subject is dark.

In the exposure control apparatus for a camera according to the first aspect, the timing setting means sets the light emission timing when the aperture area of the aperture stop is maximum (claim 3).

According to this configuration, the flash emission timing is set at the time when the aperture area of the aperture stop is maximized, so that the central portion and the peripheral portion of the lens optical system change due to the change in the aperture area of the aperture stop during exposure. The difference in the amount of transmitted light is the largest, and the apodizing effect is suitably obtained.

In the exposure control device for a camera according to the first aspect, the timing setting means is a timing input means for setting the light emission timing by an external input.

According to this configuration, the flash emission timing is set by an external input, so that
Flash emission can be performed at an arbitrary timing, whereby an apodization effect of an arbitrary degree can be obtained.

[0019]

FIG. 7 is a schematic internal configuration diagram of a first embodiment of a camera to which a camera exposure control device according to the present invention is applied. As shown in FIG. 7, the camera includes a lens portion L and a body portion B. The lens portion L is detachably attached to a lens attachment portion 1 provided on the body portion B. Has an external flash F attached.

The lens portion L has a cylindrical focus cam ring (not shown) disposed adjacent to the inner periphery of the cylindrical lens barrel 2, and is disposed adjacent to the inner periphery of the focus cam ring. Cylindrical fixed cylinder (not shown), the first group moving frame 3 (FIG. 1) supported by the focus cam ring and the fixed cylinder, and the second
The group moving frame 4 (FIG. 1), the lenses 5 and 6 supported by the first group moving frame 3 (FIG. 1), an aperture stop (hereinafter simply referred to as an "aperture") 7, and a support for supporting the stop 7. The camera includes a support frame 8, a lens 9 supported by the second group moving frame 4 (FIG. 1), and controls a focusing motor 10, an aperture drive motor 11 composed of a pulse motor, and the above-described components of the lens unit L. And a lens microcomputer 12 for performing the operation. The lens microcomputer 12 has a built-in ROM 81 in which preset data such as an open F number of a lens optical system provided in the lens unit L is stored.

The first group moving frame 3 (FIG. 1) and the second group moving frame 4 (FIG. 1) engage with a straight groove formed in the fixed cylinder and a cam groove formed in the focus cam ring, respectively. The guide pins are not shown.

On the other hand, the body portion B includes a main mirror 21, a focal plane shutter (hereinafter simply referred to as "shutter") 22 and a film 23 which are sequentially arranged on the optical axis of the lens portion L, and is arranged at an upper portion. A finder optical system including a pentaprism 24 and an eyepiece 25 is provided. The main mirror 21 is arranged at an angle of 45 ° with respect to the optical axis, and guides the light passing through the lens unit L to the finder optical system.
21 and a rear curtain 222. In addition, the main mirror 21
A known quick return mirror mechanism (not shown) is provided for retracting the lens from the position shown in FIG. 7 immediately before the start of exposure and returning the lens immediately after the end of exposure.

The body part B includes a distance measuring means (AF) 26 for measuring a distance, a light measuring means (AE) 27 disposed at an appropriate position above the eyepiece 25, and a finder comprising LEDs and the like. A display unit 28, a shutter button 29 disposed at an appropriate position on the surface, a switch SW1 which is turned on by half-pressing the shutter button 29, and a release which is turned on when the shutter button 29 is further depressed from the on state of the switch SW1. A switch SW2, a film sensitivity reading means 30 for reading the sensitivity of the film 23, a shutter driving means 31 for driving the front curtain 221 and the rear curtain 222 of the shutter 22 at a predetermined timing, and an operation provided at an appropriate position on the surface It comprises a unit 32 and a body microcomputer 33 for controlling each of the above-mentioned units of the body unit B.

With this configuration, a part of the light guided to the pentaprism 24 enters the photometric unit 27, and the brightness of the subject is detected based on the photometric value output from the photometric unit 27. Control is performed.

When the focusing motor 10 rotates during focusing, the focus cam ring rotates,
The first group moving frame 3 (FIG. 1) and the second group moving frame 4 (FIG. 1) are respectively moved by the guide pins which engage with the rectilinear grooves on the fixed cylinder and the cam grooves of the focus cam ring, whereby the lens is moved. The lenses 5 and 6 and the aperture 7 are integrally moved, and the lens 9 is independently extended and moved to a focus position.

The external flash F has a flash lamp 36 and a flash light emitting circuit 37.

FIG. 8 is an exploded perspective view showing the diaphragm 7 and its driving unit. The diaphragm 7 is composed of seven diaphragm blades 41 as shown in FIG. 8, and a driving unit for narrowing down the diaphragm 7 includes a pressing plate 42, an operation plate 43, a support frame 8, a support frame 8, The holding plate 42 is fixedly supported by the support frame 8, and the operation plate 43 is rotatably supported by the support frame 8.

Each of the diaphragm blades 41 includes a pin 51 protruding from one surface (the right side in the drawing) and a pin 51 protruding from the other surface (the left side in the drawing).
The pin 51 is fitted in a hole 53 formed in the operation plate 43, and the pin 52 is fitted in a guide groove 54 provided in the holding plate 42. .

The aperture drive motor 11 is supported by the motor base plate 44 and attached to the support frame 8 such that a gear 55 fixed to the rotation shaft of the aperture drive motor 11 meshes with a rack 56 formed on the operation plate 43.

With this configuration, when the rotation of the aperture driving motor 11 is transmitted to the rack 56, the operation plate 43 rotates around the optical axis, and the pin 51 rotates with the rotation of the operation plate 43. On the other hand, since the pin 52 moves along the guide groove 54, the angle of the aperture blade 41 changes,
The aperture area of the aperture 7 formed by the aperture blade 41 changes.

The lever 57 provided on the operation plate 43
Is fitted in a guide groove 58 provided in the support frame 8 and is configured to come into contact with a spring 59 when the aperture 7 is opened.
The opening of the aperture 7 is detected.

Next, the F-number will be described with reference to FIGS. FIG. 9 is a diagram showing an F number with respect to the aperture diameter of the diaphragm 7, and FIG. 10 is a diagram showing table data of the number of drive pulses of the diaphragm drive motor 11 when the diaphragm is stopped down with respect to the control F number. However, in FIG. 9, R ₀ is the aperture diameter of the stop when it is open.

The F number is a value obtained by quantifying the brightness and the aperture value of the lens optical system, and is determined by the focal length and the effective aperture of the lens optical system as shown in the following equation (1). In this embodiment, as shown in FIG. 9, the F-number when the aperture 7 is open is 2.8, and the exposure index, that is, the AV (Aperture Val) is from an open F-number of 2.8 to a minimum F-number of 32.
ue) The number of stages can be reduced to seven.

[0034]

F _No = f / D where F _No is the F number, f is the focal length of the lens optical system, and D is the effective aperture of the lens optical system.

In FIG. 10, when the aperture driving motor 11 is driven by eight pulses from the open F number 2.8, the aperture is stopped down to F number 4, 5.6,. Therefore, when the control F number transmitted from the body microcomputer 33 is 8, the number of drive pulses of the aperture drive motor 11 may be controlled to 24 pulses.

FIG. 1 is a block diagram showing a control configuration of the present embodiment. The operation unit 32 includes an exposure mode setting unit 61 and a flash setting unit 62. The exposure mode setting means 61 selects one of the apodize mode and the normal mode and sets the exposure mode. The apodization mode is a mode for obtaining a shooting effect approximated when an apodization filter is used, that is, an apodization effect.

The apodization filter is formed by laminating a concave lens made of ND glass whose transmittance has been reduced by coloring to a predetermined density and a convex lens made of transparent glass, and which is perpendicular to the optical axis from the center of the optical axis. This is a filter having such characteristics that the transmittance decreases as the distance increases.

When this apodization filter is used, the amount of light around the blurred image is reduced.
Can be obtained. For a still subject, the density of the peripheral edge of the blur gradually decreases, so that a photograph with a soft blur and a good atmosphere as a whole can be obtained. The defocus image is improved. Does not cause false resolution. A beautiful blurred picture without double-line blur is obtained. The defocused image is true to the shape of the original object. When the open F-numbers are equal, the depth of focus becomes deep. In a blurred image of a subject having a different color, color turbidity is less likely to occur. The adverse effect on the image due to aberration is reduced, and the focused image is improved. At the start of exposure, a moving image is obtained that becomes thinner at the start of exposure and becomes darker as exposure ends, and the direction and degree of movement can be expressed.

The flash setting means 62 sets on / off whether or not the flash lamp 36 emits light.

The body microcomputer 33 has a RAM 71, an RO
M72, exposure calculation means 73, shutter control means 74 and flash control means 75 are provided. RAM 71 is
It temporarily stores data. ROM 72 is
In the apodize mode, the preset number of setting steps ΔAV ₀ (ΔAV ₀ = 3 in the present embodiment) to stop down the aperture 7 from the open value, a reference shutter speed T _S0 described later, a set time T ₁ described later, and the like. The set data and the pattern of the aperture 7 in the apodize mode are stored.

In the normal mode, the exposure calculation means 73 calculates the control F number by adding the number of AV stages to be narrowed down to the open F number using the brightness of the subject detected by the photometry value of the photometry means 27, Shutter speed T
_It seeks _S. In apodize mode,
The shutter speed T _S is obtained by using the brightness of the subject and the set number of steps ΔAV ₀ .

The shutter control means 74 controls the driving of the shutter 22 via the shutter driving means 31 when the release switch SW2 is turned on. When the flash setting means 62 is on, the flash control means 75 outputs the flash light emitting circuit 3 at a timing described later.
The flash lamp 36 is caused to emit light via the switch 7.

The body microcomputer 33 further comprises:
It has the function of It is determined whether or not the lens portion L attached to the body portion B is a lens that can be photographed in the apodize mode based on a reference described later. On / off of the switch SW1 and the release switch SW2 is determined. The exposure mode set by the exposure mode setting means 61 is determined.

In the apodizing mode, the value of the set time T ₂ is determined from the obtained shutter speed T _S as described later. The time elapsed since the release switch SW2 was turned on is counted, and it is determined whether the set times T ₁ and T ₂ have elapsed. In the apodize mode, it is determined from the obtained shutter speed T _S whether or not shooting in the apodize mode is possible. When it is determined that shooting in the apodize mode is not possible, control described later such as displaying a warning to that effect on the display unit 28 in the viewfinder is performed. The warning display on the display unit 28 in the viewfinder is performed by turning on the red LED, blinking the LED, or the like.

The lens microcomputer 12 includes a ROM 81, aperture control means 82, and focus control means 83. The ROM 81 stores the open F number and the minimum F number of the lens optical system, the focal length, the ratio of the defocus amount to the required extension amount, and the number of drive pulses of the aperture drive motor 11 when the aperture is narrowed down with respect to the control F number shown in FIG. This is for storing preset data such as table data.

The lens microcomputer 12 transmits the data stored in the ROM 81 to the body microcomputer 33. The lens microcomputer 12 is provided with a body microcomputer 33.
The number of drive pulses of the aperture drive motor 11 is controlled in accordance with the control F number transmitted from the control panel 43. With this, the operation plate 43 is rotated, and the aperture 7 is opened to a predetermined AV from the open state.
It is narrowed down by the number of stages.

Next, the operation of the diaphragm 7, the shutter 22, and the flash lamp 36 in the apodize mode will be described with reference to FIGS. FIG. 2 is a timing chart showing the operation states of the diaphragm 7, the shutter 22, and the flash lamp 36.

(1) Availability of Apodize Mode In the apodize mode, the aperture 7 is set from the open state to the set value Δ
After narrowing down only AV _0, and begins to open the aperture 7, in the film exposure when the shutter 22 is opened, it opens the aperture 7 gradually. For example, the stop-down amount ΔAV ₀ from the open value of the stop 7 in the apodize mode is ΔΔ
Since AV ₀ = 3 is set, in this embodiment the open F
Since the number is 2.8, after narrowing down to about F number = 8, it gradually opens. As a result, the amount of light decreases as the distance from the center of the optical axis increases in the direction perpendicular to the optical axis, so that an apodizing effect can be obtained.

For this reason, when the diaphragm 7 is operated near the open value, the apodizing effect is best obtained. In addition, unless the open F-number of the aperture 7 is small to some extent, that is, a bright lens optical system, a good apodizing effect cannot be obtained.

Therefore, the body microcomputer 33 determines that the lens can be photographed in the apodized mode if the value of the open F-number of the aperture 7 of the lens portion L attached to the body portion B is F-number = 4 or less. Determine.

On the other hand, assuming that the aperture 7 is operated in the vicinity of the open state, when the photometric means 26 detects that the subject is bright, the required shutter speed T _S becomes a small value. In this case, assuming that the time required to open the aperture 7 by ΔAV ₀ = 3 is T _S0 , if the shutter speed decreases to T _S <T _S0 , the aperture 7 is fully opened to the open value within the exposure time T _S. Becomes impossible.

Therefore, the time T _S0 is set to the reference shutter speed T _S0.
Even if the exposure mode is set to the apodize mode by the exposure mode setting means 61, if the obtained shutter speed T _S is T _S <T _S0 , the body microcomputer 33
Determines that shooting in the apodize mode is not possible, displays a warning on the display unit 28 in the finder that shooting in the apodize mode is impossible, and prohibits the reception of the ON state of the release switch SW2. .

When it is determined that the photographing in the apodize mode is impossible, the following control may be performed. By changing the set value ΔAV ₀ = 2 and limiting the change range of the aperture 7, the aperture 7 can be fully opened to the open value within the exposure time T _S and photographing is performed. By keeping the set value ΔAV ₀ = 3 and opening the aperture 7 to the F-number = 4 without fully opening it to the open value, the change range of the aperture 7 is limited to perform photographing. With these, although the apodizing effect is slightly reduced, it is possible to perform shooting in the apodizing mode.

In FIG. 2, a curtain running time T _{F, which} is a time required for the front curtain and the rear curtain to travel from one end to the other end, is a fixed value unique to the camera and is stored in the ROM 72 of the body microcomputer 33. ing. When the shutter speed T _S is T _S <
In the case of 4T _F, since influence of the curtain movement relative increase in the opening area of the aperture 7 increases, it may be set with T _S0 = 4T _F. Also, for example, T _S0 may be set to 1/125 (second).

(2) Opening Control of the Aperture 7 The ROM 81 (FIG. 1) stores the aperture 7 as shown by a solid line in FIG.
Exposure index during the opening operation of the (AV number) changes control curve P1 to T _S = 1/125 to change speed increases (in seconds), 1/60 (sec) corresponding to stored in the shutter speed T _S such as doing. Then, the aperture control means 82 (FIG. 1) selects a change control curve corresponding to the shutter speed T _S obtained by the exposure calculation means 73 (FIG. 1), and opens the aperture 7 along the change control curve. Perform control. As a result, the light amount decreases more in the peripheral portion toward the outside.

Here, the set time T ₂ determined according to the shutter speed T _S is set so that the rear curtain 222 runs after the time t ₃ at which the aperture 7 is opened according to each change control curve P1, ie, It is determined that (t ₂ + T _S )> t ₃ .

It is also possible to control the opening of the diaphragm 7 as shown in the following (1) to (4). The ROM 81 (FIG. 1) stores a change pattern such that the change speed of the exposure index (the number of AV stages) increases during the opening operation of the aperture 7. Then, the aperture control unit 82 (FIG. 1)
As shown by the solid line in FIG. 2, a change control curve P1 corresponding to the shutter speed T _S obtained by the exposure calculation means 73 (FIG. 1) is generated from the change pattern, and the stop is formed along the change control curve P1. 7 is controlled.

The ROM 81 (FIG. 1) stores a change pattern such that the changing speed of the exposure index (the number of AV stages) during the opening operation of the aperture 7 becomes constant. Then, the aperture control means 82 (FIG. 1) generates a change control curve P2 corresponding to the shutter speed T _S from this change pattern, as indicated by the two-dot chain line in FIG. , The opening of the aperture 7 is controlled.

The ROM 81 (FIG. 1) stores an intermediate pattern between the above change patterns. Then, the aperture control unit 82 (FIG. 1)
From this change pattern, a change control curve P3 corresponding to the shutter speed T _S is generated, and along this change control curve P3,
The control of opening the aperture 7 is performed.

Referring to FIG.
Of the operating unit 32
Has a change pattern selecting means 63 for selecting any of the change patterns, as indicated by a dashed line. And
The body microcomputer 33 determines the selected change pattern, and transmits the determined change pattern to the lens microcomputer 12. The aperture control unit 82 generates a change control curve corresponding to the shutter speed T _S from the selected change pattern, and controls the opening of the aperture 7 along the change control curve.

In FIG. 1, the operation unit 32 has a narrowing amount Δ in the apodizing mode, as indicated by a one-dot chain line.
Comprising an exposure setting unit 64 for changing setting the AV _0. Body microcomputer 33 is configured to determine the narrowing amount DerutaAV ₀ that has been set, and transmits the narrowing amount DerutaAV ₀ which is determined in the lens microcomputer 12. The aperture control unit 82 controls the opening of the aperture 7 after the aperture is reduced by the set aperture amount ΔAV ₀ . For example, when ΔAV ₀ = 4,
After the aperture is stopped down to F number = 8, the opening of the aperture 7 is controlled.

According to this embodiment, for example, when the subject is a moving body, the narrowing-down amount ΔAV ₀ can be changed and set according to the moving speed of the subject, whereby the shutter speed can be changed according to the moving speed of the subject. (Exposure time) and the aperture amount of the aperture 7 can be controlled.

In this embodiment, the exposure setting means 6
The aperture value ΔAV ₀ may be set to be slightly larger by 4 so that the apodizing mode may be shot in a state where the aperture 7 does not fully open to the open value during the exposure. Even in this case, an apodizing effect can be obtained.

The set time T ₂ is set at the same time as the time t ₃ at which the aperture 7 is opened by the respective change control curves P 1, at the same time as the rear curtain 22.
2 may travel, that is, (t ₂ + T _s ) = t ₃ .

In FIG. 1, the ROM 81 stores first and second change control curves in which the opening speed of the diaphragm 7 increases at an accelerated rate. The exposure calculation means 73 calculates the obtained shutter speed T _S and the second reference shutter speed T _S10 (for example, T _S10 = _1/1).
5 seconds). If T _S <T _S10 , the first change control curve is selected, and if T _S ≧ T _S10 , the second change control curve is selected. Then, the aperture control means 82 controls the opening of the aperture 7 along the selected change control curve.

Here, the first change control curve is set so that the aperture 7 is opened in accordance with the reference shutter speed T _S0 , and the second change control curve is set to the second reference shutter speed T _S0.
The aperture 7 is set to open in accordance with _S10 . By this, each exposure time (shutter speed)
The aperture 7 will be fully opened to the open value within.

Referring to FIG. 1, the aperture control means 82
The aperture amount ΔAV ₀ is changed and set according to the open F number of the lens optical system stored in the OM 81. For example, if the open F number ≦ 2.8, ΔAV ₀ = 3, and if the open F number ≧ 4, ΔAV ₀ = 2. As described above, the change amount of the stop 7 is increased in the case of a bright lens optical system, and the change amount of the stop 7 is reduced in the case of a dark lens optical system, whereby control of the stop 7 suitable for the lens optical system can be performed. .

In FIG. 1, the operation unit 32 has a narrowing amount Δ in the apodizing mode, as indicated by a dashed line.
The body microcomputer 33 includes an exposure setting unit 64 for changing and setting the AV _0, and determines the set aperture amount ΔAV ₀ and transmits the same to the lens microcomputer 12. Then, the aperture control unit 82 increases the opening speed of the aperture 7 when the set aperture amount ΔAV ₀ is large, and decreases the opening speed of the aperture 7 when the aperture amount ΔAV ₀ is small.

[0069] According to this embodiment, with apodization effect the desired degree can be obtained by changing the setting refine amount DerutaAV _0, the diaphragm 7 regardless of the magnitude of narrowing amount DerutaAV ₀ in the exposure time (shutter speed) It can be fully opened to the open value.

[0070] (3) emission timing flash control unit 75 of the flash lamp 36 (FIG. 1), using the shutter speed T _S obtained, as shown in FIG. 2, the exposure end time (t ₂
+ T to reach the maximum light amount immediately before the _S time), thereby starting the emission of the flash lamp 36 to t ₄ time.

The flash control means 75 (FIG. 1)
The flash lamp 36 may be caused to emit light at the following timings. At the same time as the time point t ₃ when the aperture 7 is opened by the change control curve P 1, that is, at time t ₄ = t ₃ , the flash lamp 36 starts emitting light. Change control curve diaphragm by P1 7 is to start emission of the flash lamp 36 between the time point t ₃ when being in the open and exposed at the end (t ₂ + T _S time). Thus, the light amount of the flash lamp 36 can be reliably maximized when the aperture 7 is in the open state.

In FIG. 1, flash setting means 62
Has a timing setting function of arbitrarily setting the light emission timing of the flash lamp 36, and the flash control means 75 causes the flash lamp 36 to emit light at the timing set by the flash setting means 62. This allows the flash lamp 36 to emit light at a desired timing according to the subject.

Next, the photographing operation will be described with reference to FIGS. FIG. 3 is a flowchart of the photographing operation procedure, and FIGS. 4 to 6 are flowcharts of the subroutine of FIG.

When the body microcomputer 33 (FIG. 1) determines that the switch SW1 has been switched from off to on, the process proceeds to the flowchart of FIG. 3 to start the photographing operation. At this time, as shown in FIG. 2, the aperture 7 is kept open.

In FIG. 3, first, lens information is read (# 100), and film sensitivity is read (# 11).
0) Then, a photometric value, that is, brightness data of the subject is captured (# 120), and the set exposure mode is captured (# 130).

Next, it is determined whether the set exposure mode is the apodize mode (# 140). If the exposure mode is not the apodize mode (NO in # 140), the normal mode is determined using the photometric value obtained in # 120. Is calculated, that is, the number of steps to be narrowed down is calculated, and the number of steps is added to the open F number sent from the lens microcomputer 12 to calculate the control F number.
The number is transmitted to the lens microcomputer 12 (# 15
0), proceed to # 210.

On the other hand, if the exposure mode is the apodize mode in # 140 (YES in # 140), it is determined whether or not the lens of the lens unit L is a lens that can be photographed in the apodize mode (# 160). If it is not possible (NO in # 160), a warning display to that effect is displayed on the display unit 28 in the viewfinder (# 170), and the release switch S
The acceptance of ON of W2 is prohibited (# 180), and this routine ends.

On the other hand, if the photographing is possible in the apodize mode in # 160 (YES in # 160), the process proceeds to the exposure control value calculation subroutine of the apodize mode described later (# 190).

Next, it is determined in the subroutine # 190 whether or not the release switch SW2 is prohibited from being turned on (# 200). If prohibited (YES in # 200), this routine is terminated. ,
If the reception of the ON of the release switch SW2 is not prohibited (NO in # 200), the defocus amount is calculated using the output of the distance measuring unit 26, and the data on the driving amount of the focusing motor 10 is transmitted to the lens microcomputer 12. Then, the driving of the focusing motor 10 is controlled by the lens microcomputer 12 to perform focusing (# 210).

Next, it is determined whether or not the release switch SW2 is on (# 220). If it is on (# 22)
0, YES), it is determined whether the exposure mode is the apodize mode (# 230), and if not the apodize mode (NO in # 230), the process proceeds to a shooting operation subroutine of a normal mode described below (# 240). This routine is terminated. On the other hand, if the exposure mode is the apodize mode (#
(YES in 230), the process proceeds to the apodizing mode shooting operation subroutine described below (# 250), and this routine is ended.

On the other hand, if the release switch SW2 is off at # 220 (NO at # 220), it is determined whether or not the switch SW1 is on (# 260). If it is on (YES at # 260), # Returning to 220, if it is off (NO in # 260), this routine ends.

FIG. 4 is a flowchart of the exposure control value calculation subroutine of the apodize mode of # 190 in FIG. First, the set value ΔAV ₀ of the aperture amount of the aperture 7 is taken in (# 300), and the set values ΔAV ₀ and # 120
The shutter speed T _S is obtained using the photometric value obtained in (1), and the value of the set time T ₂ is determined according to the shutter speed T _S (# 310).

Next, the obtained shutter speed T _S is compared with the reference shutter speed T _S0 (# 320), and T _S <
If T _S0 (YES in # 320), it is determined that shooting in the apodize mode is impossible, and a warning is displayed on the display section 28 in the viewfinder (# 330), and the release switch SW2 is turned on. Is prohibited (# 34)
0), this subroutine ends.

On the other hand, if T _S ≧ T _S0 in # 320 (NO in # 320), a change control curve of the diaphragm 7 according to the shutter speed T _S is selected (# 350), and this subroutine is terminated. I do.

FIG. 5 is a flowchart of the photographing operation subroutine in the normal mode of # 240 in FIG. First, the main mirror 21 is retracted (# 400), and the aperture 7 is narrowed down to the control F number calculated in # 150 (# 41).
0), the shutter 22 is driven in this narrowed state, and the film is exposed (# 420).

FIG. 6 is a flowchart of the photographing operation subroutine in the apodize mode of # 250 in FIG. First, the counting of the elapsed time is started (# 500), the main mirror 21 is retracted (# 510), and the aperture 7 is set to the set value Δ.
AV _{0 is} narrowed down (# 520).

[0087] Then, the elapsed time being counted is discriminated whether reaches the set time T ₁ (# 530), waits until the elapse of the set time T ₁ (NO at # 530), the set time T ₁ If elapsed (YES in # 530), opening control of the throttle 7 starts (# 540, t ₁ point in FIG. 2).
This opening control is performed along the change control curve selected in # 350.

[0088] Then, the elapsed time being counted is discriminated whether reaches the set time T ₂ (# 550), waits until the elapse of the set time T ₂ (NO in # 550), the set time T ₂ When the time has elapsed (YES in # 550), the shutter 22 is driven to start exposure of the film (# 56).
0, t ₂ time point 2), then the flash lamp 36 is emitted to the exposure just before the end (# 570, t ₄ time in Figure 2).

The calculation of the exposure control value in the apodize mode of # 190 in FIG. 3 may be performed by the procedure shown in FIG. 11 instead of FIG. FIG. 11 is a flowchart showing the procedure of the exposure control value calculation subroutine of the apodizing mode of # 190 in FIG. 3 in the case of "(2) opening control of the aperture 7".

# 600 to # 640 correspond to # 300 to # 640 in FIG.
Description is omitted because it is the same as # 340. In _T620 , if T _S ≧ T _S0 (NO in # 620), then
The shutter speed T _S is compared with the second reference shutter speed T _S10 (# 650), and if T _S <T _S10 (Y in # 650)
ES), the first change control curve is selected (# 660),
On the other hand, if T _S ≧ T _S10 (NO in # 650), the second change control curve is selected (# 670).

As described above, according to the first embodiment, the aperture 7 and the shutter 22 are provided, and the aperture area of the aperture 7 is changed while the shutter 22 is opened and the film is exposed. By reducing the amount of light in the peripheral portion, it is possible to obtain an apodized effect, that is, a beautiful blurred photograph without two-line blur.

FIG. 12 is a schematic internal configuration diagram of a second embodiment of a camera to which the camera exposure control device according to the present invention is applied. Components having the same functions as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. In this camera, as shown in FIG. 12, a lens portion L and a body portion B are integrally formed.

The lens section L includes a lens group 91 supported by a first group moving frame (not shown), a lens group 92 supported by a second group moving frame (not shown), a lens shutter 93, and a lens shutter 93. , A focusing motor 10, and shutter driving means 95 for driving a lens shutter 93.

On the other hand, the body portion B includes a film 23 disposed on the optical axis of the lens portion L, and a finder optical system including an objective lens 96 and an eyepiece 97 disposed on the same optical axis at the top. Together with a distance measuring means (AF) 2
6, photometric means (AE) 27, and display unit 2 in the finder
8, shutter button 29, switch SW1, release switch SW2, film sensitivity reading means 30
, An operation unit 32, and a camera microcomputer 98 for controlling the above units. The body portion B has a flash lamp 36 built in at the upper end and a flash light emitting circuit 37.

It is to be noted that a part of the light incident on the film 23 is incident on the photometric means 27.

With this configuration, when the focusing motor 10 rotates during focusing, the first group moving frame and the second group moving frame move respectively, whereby the lens groups 91 and 92 are extended independently of each other, and the focus position is adjusted. Move up to.

The shutter driving means 95 is composed of an electromagnet, a spring, or the like, and opens and closes the lens shutter 93 according to the exposure mode in the apodizing mode or the normal mode.

The camera microcomputer 98 is substantially the same as the body microcomputer 33 and the lens microcomputer 1 shown in FIG. 1 of the first embodiment.
It has two functions. However, the aperture control unit 82
By controlling the driving of the shutter driving means 95 instead of the function of the shutter control means 74, the opening and closing of the lens shutter 93 is controlled as described later.

[0099] Also, the camera microcomputer 98 incorporates a ROM99, The ROM99, data such as setting the F-number F ₀ and the reference shutter speed T _S1, which is set in advance to be described later is stored.

FIG. 13 is a schematic structural view of the lens shutter 93, in which (a) shows an open state and (b) shows a closed state. The lens shutter 93 has both an aperture function and a shutter function, and includes five sector blades 101 and a sector ring 102 as shown in FIG. The sector blade 101 has a long hole formed at one end and a round hole formed substantially at the center, and a pin fixed to the camera body fits into the long hole, and a pin fixed to the sector ring 102. Are fitted in and supported by the round holes.

The sector ring 102 is arranged so that its center coincides with the optical axis, is supported so as to be rotatable around the optical axis, and is configured to be rotated by shutter driving means 95 (FIG. 12). ing.

With this configuration, in FIG.
When the sector ring 102 rotates clockwise, the opening area of the lens shutter 93 decreases, and FIG.
When the sector ring 102 rotates counterclockwise, the opening area of the lens shutter 93 increases.

Next, the operation of the second embodiment will be described with reference to FIG. FIG. 14 is a timing chart showing an operation procedure of photographing and operation states of the lens shutter 93 and the flash lamp 36 in the second embodiment. (1) Photographing operation The exposure time of the film, that is, the shutter speed T _S and the opening area of the lens shutter 93 are determined by the photometric means 27 (FIG. 12).
Is calculated using the photometric value obtained by Then, as in the first embodiment, when the switch SW1 is turned on, a photometric value is captured, and an exposure calculation is performed using the photometric value,
When the release switch SW2 is turned on, the film is exposed.

When the exposure mode set by the operation section 32 (FIG. 12) is the normal mode, the F number and the shutter speed are obtained according to the photometric value, and the lens shutter 93 is opened up to the obtained F number. At the same time, the opening and closing are controlled so that the shutter is closed at the determined shutter speed.

[0105] On the other hand, when the exposure mode is set in the apodization mode, the lens shutter 93, after being opened to set the F-number F _0, it is opened gradually further at a constant speed. Therefore, different shutter speeds T depending on the photometric value
_S , the exposure time of the film, is determined.

The opening and closing of the lens shutter 93 is controlled as follows. When the calculated shutter speed T _S = T _S1 , the closing operation is started almost at the same time when the lens shutter 93 is fully opened to the open value (in the figure). As a result, the apodizing effect can be obtained by reducing the amount of light in the peripheral portion.

If the calculated shutter speed T _S is T _S <T _S1
In the case of, the closing operation is started before the lens shutter 93 is fully opened to the open value (in the drawing). by this,
Since the range of the peripheral portion where the amount of light decreases slightly decreases, an apodizing effect can be obtained although the amount slightly decreases.

When the calculated shutter speed T _S is T _S > T _S1
In this case, the closing operation is started after the lens shutter 93 is fully opened to the open value (in the figure). by this,
An apodizing effect can be obtained by reducing the amount of light in the peripheral portion.

[0109] (2) In the apodization mode whether the apodization mode, after opening the lens shutter 93 from shading (occlusion) state to the set F-number F _0, is gradually opened further at a constant speed. As a result, the amount of light in the peripheral portion decreases, and an apodizing effect can be obtained. Therefore, in the apodize mode, the lens shutter 9
3 is opened to the vicinity of the open value,
, The calculated shutter speed T _S becomes a small value.

In this case, as shown in FIG. 14, assuming that the time required for the lens shutter 93 to open from the closed state to the set F number F ₀ is T _S2 , the set F number F ₀ is in the range of T _S ≦ T _S2. Can not be opened further.

Therefore, even if the exposure mode is set to the apodize mode, if the shutter speed T _S obtained as a result of the exposure calculation is T _S ≦ T _S2 , it is impossible to take a picture in the apodize mode. That is, a warning is displayed on the display unit 28 in the viewfinder, and the acceptance of the ON state of the release switch SW2 (FIG. 12) is prohibited.

When the shutter speed T _S is T _S ≦ T _S2 , a warning is displayed on the display unit 28 in the finder that the shooting in the apodize mode is impossible, and the shooting operation is performed as it is. It may be.

(3) Flash Timing of Flash Lamp 36 The camera microcomputer 98 (FIG. 12) uses the obtained shutter speed T _S to determine the opening area of the lens shutter 93 immediately before the end of the exposure, as shown in FIG. maximum to reach the maximum light when, and to start emission of the flash lamp 36 at t ₅ times.

In FIG. 12, the operation unit 32 has a timing setting function for arbitrarily setting the light emission timing of the flash lamp 36, and the camera microcomputer 98 operates the flash lamp 36 at the timing set by the operation unit 32. May be emitted. This allows the flash lamp 36 to emit light at a desired timing according to the subject.

Note that the present invention is not limited to the above embodiment, but can adopt the following modified embodiments (1) and (2).

(1) As shown by the broken line in FIG.
A light receiving element 38 for receiving the light reflected by the light emitting element 3 may be provided. At the time of photographing, the light passing through the lens optical system reaches the film 23 and is exposed when the main mirror 21 is retracted upward, but the light enters the finder optical system due to the retreat of the main mirror 21. Therefore, the photometry by the photometry means 27 cannot be performed during the exposure.

On the other hand, according to this embodiment, the reflected light of the film 23 can be detected by the light receiving element 38, so that the exposure control corresponding to the light amount change during the exposure, for example, the light emission amount of the flash lamp 36 TTL control for controlling in real time while measuring the reflected light of the film 23 can be performed.

(2) The warning to the effect that shooting in the apodize mode is not possible may be performed by voice using a voice synthesizing unit or a buzzer instead of displaying on the display unit 28 in the finder. .

[0119]

As described above, according to the present invention,
Since the flash emission timing is set while the shutter is open, the aperture area of the aperture stop is changed while the shutter is open, and the flash is emitted at the set flash timing. The amount of light passing through the central portion of the optical system is different from the amount of light passing through the peripheral portion, and an apodizing effect can be obtained even when the subject is dark.

Further, by setting the flash emission timing immediately before the end of the exposure time, the influence of the difference in the amount of light passing through the central portion and the peripheral portion of the lens optical system due to the change in the opening area of the aperture stop during the exposure can be reduced. It can be left on the film, so that an apodized effect can be obtained even when the subject is dark.

By setting the flash emission timing when the aperture area of the aperture stop is the maximum, the difference in the amount of light passing through the central portion and the peripheral portion of the lens optical system due to the change in the aperture area of the aperture stop during exposure can be reduced. It can be maximized, whereby the apodizing effect can be suitably obtained.

Further, by setting the flash emission timing by an external input, the flash emission can be performed at an arbitrary timing, whereby an apodization effect of an arbitrary degree can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a control configuration according to an embodiment.

FIG. 2 is a timing chart showing a state of each unit after a switch is switched from off to on.

FIG. 3 is a flowchart of a shooting operation procedure.

FIG. 4 is a flowchart of a subroutine for calculating an exposure control value in an apodizing mode of # 190 in FIG. 3;

FIG. 5 is a flowchart of a subroutine of a photographing operation in a normal mode in # 240 of FIG. 3;

FIG. 6 is a flowchart of a photographing operation subroutine in the apodize mode of # 250 in FIG. 3;

FIG. 7 is a schematic internal configuration diagram of an embodiment of a camera to which a camera exposure control device according to the present invention is applied.

FIG. 8 is an exploded perspective view showing a diaphragm and its driving unit.

FIG. 9 is a diagram showing an F number with respect to an aperture diameter of a diaphragm.

FIG. 10 is a diagram showing table data of the number of drive pulses of an aperture drive motor at the time of aperture reduction with respect to a control F number.

11 is a flowchart showing a different example of a procedure of a subroutine for calculating an exposure control value in the apodizing mode of # 190 in FIG. 3;

FIG. 12 is a schematic internal configuration diagram of an embodiment of a camera to which a camera exposure control device according to the present invention is applied.

13A and 13B are schematic structural views of a lens shutter, wherein FIG. 13A shows an open state and FIG. 13B shows a closed state.

FIG. 14 is a timing chart showing an operation procedure of photographing and operation states of a lens shutter 93 and a flash lamp 36 in the second embodiment.

[Explanation of symbols]

 5, 6, 9 Lens 7 Aperture Stop 10 Focusing Motor 11 Aperture Driving Motor 12 Lens Microcomputer 22 Focal Plane Shutter 26 Distance Measuring Means 27 Photometry Means 31 Shutter Driving Means 33 Body Microcomputer 36 Flash Lamp 37 Flash Light Emitting Circuit 43 Operation Board 71 RAM 72 ROM 73 Exposure calculation means 74 Shutter control means 75 Flash control means 81 ROM 82 Aperture control means 83 Focus control means 91, 92 Lens group 93 Lens shutter 94 Support frame 95 Shutter drive means 98 Camera microcomputer B Body part F External flash L lens Section SW1 switch SW2 Release switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeaki Tochimoto 2-3-13 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Junichi Yai 2-chome Azuchicho, Chuo-ku, Osaka City No. 13 Osaka International Building Minolta Co., Ltd.

Claims (4)

[Claims] 1. A camera comprising: an aperture stop for limiting the amount of light passing through a lens optical system and reaching a film; and a shutter for exposing the film by opening an exposure time from a light-shielded state. Aperture control means for changing the opening area of the aperture stop while
An exposure control device for a camera, comprising: timing setting means for setting a light emission timing for emitting a flash while the shutter is open; and light emission control means for emitting a flash at the set emission timing. 2. An exposure control apparatus for a camera according to claim 1, wherein said timing setting means sets said light emission timing immediately before the end of said exposure time. 3. An exposure control apparatus for a camera according to claim 1, wherein said timing setting means sets said light emission timing when the aperture area of said aperture stop is maximum. apparatus. 4. An exposure control apparatus for a camera according to claim 1, wherein said timing setting means is timing input means for setting said light emission timing by an external input.