JP2969880B2 - Flash emission control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash emission control device that emits a flash a plurality of times in a camera that uses an aperture shutter and a flash device in which the aperture diameter and shutter time are variable.

[Prior Art] Conventionally, in a lens shutter camera using an aperture / shutter, as in a flashmatic (FM) system, an appropriate exposure is obtained from a shooting distance and a guide number (GNO.) Of a flash. When the aperture value is reached, a flash is emitted, or a flash is emitted while the shutter is closed so that a shadow is formed behind the moving object (for example, see Japanese Patent Application Laid-Open No. 63-15 / 1988).
No. 9833). Further, there is also a device that performs multi-flash while the shutter is constantly opened.

[Problems to be Solved by the Invention] In the method disclosed in the above-mentioned publication, the flash is not fired a plurality of times, and even in the case of the above-described multi-flash, the exposure amount for each light emission Does not change, it is difficult to take a photograph in which a moving subject gradually appears.

The present invention has been made under the above background. In a camera using an aperture / shutter having a variable aperture diameter and a variable shutter time, a flash is emitted a plurality of times during opening and closing of the shutter, so that a moving subject is gradually increased. An object of the present invention is to provide a flash light emission control device capable of easily taking a picture as it appears.

Means for Solving the Problems In order to achieve the above object, the present invention provides an aperture / shutter having a variable aperture diameter and a shutter time, a camera using a flash device, and a shutter being opened or closed. A flash light emission control device in which a flash is emitted a plurality of times.

[Operation] In the above configuration, the exposure of a moving subject or the like can be gradually changed arbitrarily by changing the rising characteristics of the opening of the shutter or the falling characteristics of closing the shutter, and photographing by flashing a plurality of times during the shooting. it can.

[Effects of the Invention] As described above, according to the present invention, it is possible to arbitrarily change the rising and falling characteristics of opening or closing of a shutter by using an aperture / shutter having a variable aperture diameter and shutter time. Utilizing the flash a plurality of times during opening or during opening of the shutter makes it possible to easily take a photograph in which the moving subject gradually appears or disappears.

Hereinafter, a camera to which the present invention is applied will be described with reference to the drawings.

FIG. 1 shows a block configuration of a circuit of the camera. This camera is sequence-controlled by a microcomputer (abbreviated as a microcomputer) 1. Switch S0 is provided for microcomputer 1.
The operation signal from ~ S5 is input. The main switch S0 activates the camera when it is ON. The photometric distance measuring switch S1 is turned on by pressing the release button one step down. The release switch S2 is turned on by pressing the release button two steps. Zoom in switch S3, zoom out switch S4
Are turned on and off by operating the zoom button, respectively.
The mode changeover switch S5 is used to switch a shooting mode described later.

The photometric unit AE measures the luminance of the object scene and sends it to the microcomputer 1.
The distance measuring unit AF measures the distance to the subject and sends it to the microcomputer 1. The distance measurement is performed, for example, at three points in the object field, and the range of the distance measurement is AF2 in the middle of the object field, right AF3, and left AF1 as shown by dotted circles in FIG. The flash unit 2 is connected to the microcomputer 1 via the interface IF and the charge detection unit 3. The flash unit 2 includes a high-voltage circuit, a capacitor, a xenon tube, and the like.
In response to a signal from the TRG, charging of the capacitor and control of light emission are performed via the interface IF. The charge state of the capacitor is determined by the microcomputer 1 via the charge detection unit 3.
Is detected by inputting a signal to the terminal RDY.

The stepping motor M1 for driving the shutter is controlled by the microcomputer 1 via the driver 4. The stepping motor M2 for driving the lens is controlled via the driver 5. The upper part 6 of the film and the zoom mechanism 7 are provided by the microcomputer 1
, Respectively, for winding and rewinding the film and driving the zoom lens. The magnet Mg is a member for preventing occurrence of ringing (vibration) when the shutter is stopped at a desired position, and is a component of a plunger described later.

FIG. 3 shows a program line for shutter control of the present camera. In the present camera, as will be described later, an appropriate program line is automatically selected by switching the rising characteristic of the shutter based on the result of distance measurement, that is, according to the shooting purpose. The line is a program line for sports photography and portrait photography (sports mode), the line is a standard photography (standard mode), and the line is a commemorative photography (commemorative photograph mode or software photograph mode).

And the sports program line is located at a higher speed than the standard program line. The commemorative photo shooting program line is located at a lower speed than the standard program run-in and is used when you want to increase the depth of field of commemorative photos etc. The minimum aperture is maintained up to 1/30 second of the shutter speed. When the exposure control value Ev is 8 or less, the shutter speed becomes 1/30 sec, the aperture becomes F4, and the flash fires.

FIG. 4 shows a drive waveform and an aperture waveform of the shutter of the camera. (A-1) (a-2) is the standard mode, (b-1)
(B-2) is a sport mode, (c-1) and (c-2) are commemorative photo modes, and (d-1) and (d-2) are shutter drive waveforms and aperture waveforms in a soft photo mode.

As shown in the figure, the pulse width of the shutter driving stepping motor is shorter in the sport mode than in the standard mode, and the opening waveform has a sharp rise and fall. In the commemorative photo mode, the number of drive pulses is set to only one pulse, and the opening is opened only up to, for example, F22. In the soft photographic mode, the drive pulse width is long when the initial opening is small, and is shortened as the opening becomes large. Therefore, the opening waveform has a gentle rise at first, and becomes gradually steep. On the other hand, when the shutter is closed, the fall is steep at first and gradually becomes gentle. Here, the stepping motor is a case of two-phase drive, and the respective shutter drive pulse waveforms are shown separately in the upper and lower directions.

FIG. 5 is a flowchart showing the operation of the camera, which will be described below with reference to FIG.

When the battery is loaded in the camera, first, it is determined whether the main switch SO is ON or OFF from “START” (step #
1). If the main switch S0 is ON, the photometric distance measurement switch S1 is determined (# 2). If the switch S1 is ON,
The process proceeds to the photometry ranging routine, and if it is OFF, the zoom-in switch S3 is determined (# 3). Hereinafter, the judgment of the zoom-out switch S4 and the mode changeover switch S5 is performed in the same manner (# 4, # 5). If the switch is ON in any of the judgments, "zoom-in", "zoom-out", "mode changeover" To any of the routines. If all of the switches S1 to S5 are OFF, the state of charge of the capacitor for flash emission is determined (# 6). If the charging is completed, that is, if the flash is being emitted, the boosting is stopped (# 9), and the process returns to # 1 and repeats the above operations. When the main switch S0 is OFF in # 1, the boosting is stopped (# 1).
8) Then, return to # 1.

 FIG. 6 shows a flowchart of "mode switching".

This camera has five types of shooting modes.
That is, the above-described standard mode, sports mode, commemorative photo mode, soft photo mode, and fantasy mode. In the fantasy mode, an effect similar to that of a soft filter or an effect such as zooming between exposures is obtained by driving a focusing lens during exposure. In "mode switching", mode switching is performed among six types of modes obtained by adding an auto program mode described later to the five types of photographing modes. Set the mode switch S5 to 1
Every time the button is pressed, as shown in FIG. 6, the mode sequentially changes from the auto program mode to the standard mode to the sports mode to the commemorative photo mode to the soft mode to the fantasy mode.

The auto program mode is a mode for automatically switching among the above-described three modes, the standard mode, the sports mode, and the commemorative photo mode, based on the result of measuring the subject distance. “Zoom in” and “zoom out” are routines for switching the focal length.

FIG. 7 shows a flowchart from the photometric distance measurement to the release.

In the "photometry and distance measurement" routine, first, boosting of the flash is stopped (# 11). Next, perform photometry and ranging (# 12,
# 13) The control exposure value and the distance are determined (described later) based on the result of the photometric distance measurement (described later) (# 14), and the voltage of the capacitor for flash emission is determined (# 15). If boosting is necessary, boosting is started (# 16), and then the main switch S0,
The photometric distance measurement S1 is determined (# 19, # 20). Here, if the switch S0 or S1 is OFF, the above “START”
Return to If both switches are ON, the process returns to step # 15 and repeats the above. If the voltage level of the capacitor for flash emission has reached the predetermined level in # 15, the boosting is stopped (# 17), and ON / OFF determination of the release switch S2 is performed (# 17).
18). If it is OFF, proceed to # 19 and repeat the above-mentioned operation. If it is ON, the lens is driven in accordance with the distance obtained in # 14 (# 21), the shutter is driven, and the exposure described later is performed (# 22). When the exposure is completed, the lens is reset (# 23), the film is wound up (# 24), and "STAR
Return to "T".

FIG. 8 shows a flowchart of the above-described determination of the exposure value and the distance, which will be described below.

First, the data of the left AF1, the center AF2, and the right AF3 of the object field obtained by the above-described distance measurement are compared (# 101), and the closest data is set as the control distance (# 102). Next, it is determined whether or not the shooting mode is the auto program (# 103). If the auto program is not selected, the process proceeds to # 106, and the control exposure value is determined based on the subject brightness and the film sensitivity obtained by the photometry described above. I do.

If the automatic program is selected in step # 103, the process proceeds to step # 104, where the farthest data of the three distance measurement data and the latest data are compared. If the difference is larger than 4 zones,
It is determined that the subject is at a short distance or a long distance, and a program line narrowed down to gain the depth of field, that is, a commemorative photo mode is selected (# 105). When the zone difference obtained in # 104 is 0, since all subjects are at substantially the same distance and the depth of field may be shallow, the program line from the high-speed shutter speed (SS), that is, the sports mode is selected. (# 108). At other times, that is, when the zone difference is 1 or more and 4 or less, the standard mode is selected (# 109). After that, the exposure value is determined in # 106, and the exposure value and distance determination routine ends.

 FIG. 9 shows a flowchart of the exposure operation.

In this routine, first, the shooting mode is determined (# 201, # 216, # 219, # 222), and to the standard mode, to # 202; to the sports mode, the fantasy mode to # 217; If the mode is the photograph mode, go to # 220. If the mode is the soft mode, go to # 223. Then, the shutter opening pulse number of the shutter blade and the stop time are respectively shown in FIG.
(# 202, # 217, # 22)
0, # 223), and then the ROM address changes from 00H to 0 depending on the mode.
It is set to any of 3H and proceeds to # 204. 00H to 03H set here are addresses in the respective modes of the ROM table shown in FIG. 10A for obtaining the drive pulse width of the stepping motor M1 for activating the shutter.

Here, the number of open pulses and stop time
This will be described with reference to FIG. FIG. 9 is an example of a ROM table for obtaining the shutter opening pulse number and the stop time from the shutter control value in the standard mode. For example, when the brightness of the subject is 13 Ev, the microcomputer 1 sends the stepping motor M1 for two pulses in the opening direction of the shutter, then pauses for 2 ms, and the same amount as when the stepping motor M1 was sent in the closing direction of the shutter earlier. return. If it is 8Ev, 6 pulses are sent, 30 ms pause, and 6 pulses are returned. By adopting such a control method, the shutter speed and the aperture value can be changed by changing the number of pulses and the stop time even with the same control value. When the shutter reaches a predetermined aperture value, the plunger is operated to prevent occurrence of ringing.

FIG. 10A is a table of the pulse width of the shutter drive pulse. In the upper bits, the row of 0 is the pulse width of the standard mode, the row of 1 is the pulse width of the sport and fantasy mode, the row of 2 is the pulse width of the small aperture mode, and the row of 3 is the pulse width of the soft mode. . The lower bits 0, 1, 2, ... are the first pulse of the shutter open pulse, respectively.
The second pulse corresponds to the third pulse.

To describe the soft mode as an example, assuming now that the number of shutter opening pulses and the stop time determined by the shutter control value are 5 pulses and 4 mS, respectively, the microcomputer 1 first determines the first pulse of the shutter opening. Drive with pulse width of 10mS. Next, the shutter is driven according to the value of the ROM table, such as 8 ms for the second pulse and 6 ms for the third pulse, and after a pause of 4 ms, the ROM table is then moved in the opposite direction to when the shutter was opened. Reference is made and the shutter is closed.

As described above, the rising and falling characteristics of the shutter are changed by changing the shutter drive pulse width, the number of shutter opening pulses, and the stop time, respectively.
Various open waveforms can be obtained.

Returning to FIG. 9, the description will be continued. In step # 204, the stepping motor M1 for driving the shutter is sent by one pulse in the opening direction. Next, it is determined whether or not the shutter drive has been completed for the number of open pulses (# 205). If not completed, the above-described pulse width is read (# 206). (# 207) If the time passes, the flow returns to # 204, and the above operation is repeated. When the stepping motor M1 is driven by the number of open pulses, the process proceeds to # 208. It is determined whether the shooting mode is the fantasy mode or another mode. And
In the fantasy mode, the AF lens is driven in the near or far direction by a predetermined number of steps (# 209), and the process proceeds to # 210. In # 210, the stop time is read, and then the time elapses (# 211). Thereafter, the shutter is closed in a manner reverse to that when the shutter is opened (# 212 to # 215).

FIG. 11 shows a flowchart of an exposure operation according to another embodiment. This example shows a case where flash photography is performed in the sports mode, and the operation until the shutter is opened by a predetermined number of pulses is the same as that in the sports mode in the flowchart of FIG. After opening for a predetermined pulse, #
At 308, a flash is emitted. Next, the driving of the zoom lens is started in the short focus direction (# 310). Next, the flash is fired every 0.1 second until the stop time ends (# 311, # 312, # 313). When the stop time ends, the shutter is closed by driving in the closing direction, which is opposite to the opening of the shutter. By performing control as described above, a photograph in which zoom between exposures and multiple flashes are combined can be taken.

FIGS. 12 (a) and 12 (b) show a shutter opening waveform and flash emission timing according to still another embodiment.

In both cases, the flash is emitted a plurality of times during the opening and closing operation of the shutter. FIG. 12 (a) slows the rising of the shutter in the opening direction and periodically flashes the flash a plurality of times during the driving in the opening direction. It is emitting light. The aperture is a small aperture at first, and gradually opens each time the flash fires. Therefore, in the multiple flash, the first exposure is darker, and the later exposure is brighter. FIG. 12 (b) is the reverse of FIG. 12 (a), in which the falling of the shutter in the closing direction is slowed, and the flash is emitted a plurality of times periodically during driving in the closing direction. Things are darker. For this reason, when the subject is moving, the former can perform fade-in shooting in which the subject gradually appears, and the latter can perform fade-out shooting in which the subject gradually disappears.

 FIG. 13 shows a circuit configuration of the flash unit.

This circuit boosts the power supply voltage Vcc and raises the main capacitor C3
, A DC-DC converter 11, a constant voltage generation circuit 12, a trigger circuit 13 for exciting the flash discharge tube Xe, and a light emission control circuit 14.

The DC-DC converter 11 includes an oscillation transistor Q1, switching transistors Q6, Q7, resistors R1, R2, R18, R19, R20, R2
1, composed of an oscillation transformer T1 and a diode D5. The oscillation transformer T1 has a primary winding P, secondary windings S1 and S2, and an auxiliary winding F
The main capacitor C3 is connected to the secondary winding S1 via a rectifier diode D3. This allows
After the power supply phase Vcc is boosted and rectified by the diode D3, the main capacitor C3 is charged.

The main capacitor C3 includes a trigger circuit 13 for exciting the flash discharge tube Xe, a flash discharge tube Xe via a delay circuit including a coil L and a diode D4, and a resistor R22 connected to the charge detection terminal ZDI. ZD2 is connected. By inserting a delay circuit, the main capacitor
The electric charge does not suddenly move from C3 to the flash discharge tube Xe, so that it is possible to reduce excess light emission due to delay of the microcomputer 1 or the like.

The trigger circuit 13 includes a capacitor C4, a resistor R4, and a transformer T2.
Consists of A constant voltage generating circuit 12 is connected to a secondary winding S2 of the oscillation transformer T1 via a rectifying diode D2. This constant voltage generating circuit 12 is a circuit for supplying a constant voltage to a light emission control circuit 14 controlled by the microcomputer 1, and includes a transistor Q2 having a collector connected to the cathode of a diode D2, and a cathode connected to the base of the transistor Q2. Zener diode ZD with grounded anode
1, a resistor R3 connected between the collector and the base of the transistor Q2, and a capacitor C2 connected to the emitter of the transistor Q2 and acting as a driving power supply for the light emission control circuit 14.

The light emission control circuit 14 is a circuit that controls light emission of the flash discharge tube Xe by controlling ON / OFF of the IGBT, and includes transistors Q3, Q4, Q5, Q8, and resistors R8 to R17.

Note that the number of turns of the secondary winding S1 and the secondary winding S2 of the transformer T1 is such that when the main capacitor C3 is charged to a voltage necessary for causing the flash discharge tube Xe to emit light, the capacitor C2
It is designed to be charged to the voltage necessary to drive the.

In FIG. 13, when the terminal FCO is set to “L”, the transistors Q7, Q6, Q1 are turned on, the DC-DC converter 11 starts operating, and the capacitor C3 is charged. Further, electric power is supplied from the secondary winding S2 to the constant voltage circuit 12, and the circuit 12 operates to supply electric power to the light emission control circuit 14, whereby the flash light emission preparation state is established. At this time, when the camera is released by operating the release operation means, the shutter starts to open after a series of operations. The microcomputer 1 sets the terminal TRGO to “L” at an appropriate timing. Then, the transistors Q8, Q5, Q4 are turned on, a voltage is applied to the gate of the IGBT via the resistor R8, and the IGBT is turned on. As a result, a capacitor is connected to the primary winding of the transformer T2.
The charging current of C4 flows, a trigger pulse is generated from the secondary winding of the transformer T2, and the flash discharge tube Xe is connected to the main capacitor C3.
Light emission is started by the discharge current of.

Thereafter, when the terminal TRGO is pulled up to “H”, the transistor Q3 turns on and the transistors Q8, Q5, Q4 turn off. When the transistor Q3 is turned on, the gate of the IGBT is grounded, and the IGBT is turned off.
Turn off. As a result, no discharge current flows to the flash discharge tube Xe, and light emission stops. Transistors Q8, Q5, Q4 are OF
When F, the capacitor C2 can be prevented from discharging through the transistor Q4, the resistor R8, and the transistor Q3.

As described above, by controlling the terminal TRGO at an appropriate timing, an arbitrary flash emission intensity can be obtained. Also, continuous flash emission is possible.

FIG. 14 shows an example of a shutter mechanism of the camera. This shutter is a diaphragm / shutter that can vary the aperture diameter and the shutter time. The configuration and operation of the shutter will be described below.

This shutter includes three shutter blades 21, a sector gear 22 with which the shutter blades 21 are engaged as a component of a mechanism for driving the shutter blades 21, and a driving stepping motor 23 (M1 in FIG. 1). And a reduction gear 24. Further, when the aperture diameter reaches a desired aperture value, a plunger 25 driven by a magnet Mg excited by energization is connected to the plunger 25. Brake lever to brake against sector gear 22
26 and. Further, as described above, the microcomputer 1 applies a brake to the stepping motor 23 when the aperture diameter reaches a desired aperture value.

In the above configuration, when the release button is pressed down, the stepping motor 23 starts rotating clockwise from the shutter closed state in FIG. 14 (c), the reduction gear 24 rotates counterclockwise, and the sector gear 22 starts rotating. Rotate clockwise. The shutter blade 21 is rotatably supported on a substrate (not shown) by a shaft 21a, and a pin 22a of a sector gear 22 is fitted into a long hole 21b of the blade 21. Accordingly, the shutter blades 21 rotate counterclockwise in response to the rotation of the sector gear 22, and the shutter opens to enter an exposure state.

When the shutter reaches the desired opening value, the stepping motor 23 is brought into the braking state, and the plunger is moved.
When a current is supplied to the plunger 25, the brake lever 26 having one end coupled to the plunger 25 starts to rotate clockwise around the rotating shaft 26 a at the other end, and comes into contact with the sector gear 22. As a result, it is possible to reliably apply a brake to the shutter drive mechanism, to prevent occurrence of ringing,
A desired aperture value can be obtained with high accuracy. At this time, the shutter is in the state shown in FIG. 14 (b).

Next, when closing the shutter blade 21, the plunger
25 is turned off, and the stepping motor 23 is rotated counterclockwise to return to the state shown in FIG. 14 (c). FIG. 7A shows a state in which the shutter is opened. In this case, since the open aperture value is determined by the opening of the sector gear 22, the lever 26 is opened.
Eliminates the need for braking.

In the above, the case where the stepping motor 23 is used for driving the shutter has been described. Next, an example in which the bimorph piezoelectric element is used for driving the shutter will be described with reference to FIGS. 15 and 16.

FIG. 15 shows a circuit for controlling a shutter using a bimorph piezoelectric element, and FIG. 16 shows a principle configuration of the bimorph piezoelectric element. As shown in FIG. 16, the bimorph piezoelectric element Bi1 has a configuration in which a metal substrate is sandwiched between piezoelectric elements A and B. When a voltage is applied to one piezoelectric element to the other piezoelectric element, the bimorph piezoelectric element Bi1 Bi1 bends. The shutter blade is driven using this force.

The shutter control circuit shown in FIG.
To Tr5, a resistor R1, and a booster circuit 31 including a DC-DC converter (DC-DC), capacitors C2 and C3, and a voltage detection circuit BC
1, transistors Tr11 to Tr20, and bimorph piezoelectric element B
and an exposure control circuit 32 composed of i1.

The boosted voltage is extracted from the secondary winding of the DC-DC converter (DC-DC), and the voltage V3 via the diode D3 is supplied to the exposure control circuit 32. The exposure control circuit 32 includes a capacitor C2 for storing charge, a voltage detection circuit BC1 for detecting a voltage stored in the capacitor C2, and a bimorph piezoelectric element B.
i1, a capacitor C3 connected in parallel to the bimorph piezoelectric element Bi1, and control transistors Tr11 to Tr20.

In the above configuration, if the voltage detection circuit BC1 detects 200V, it outputs a “H” level detection signal to the input terminal IP3 of the microcomputer 1.
Output to By inputting this signal, the microcomputer 1 turns off the boosting control transistor of the boosting circuit 31 to stop boosting. Next, the control transistors Tr11 to Tr11 which apply the voltage thus obtained to the bimorph piezoelectric element Bi1.
The operation of r20 will be described.

The collector side of the transistor Tr18 of the bimorph Bi1 is
This corresponds to the piezoelectric element B in FIG. Now, the transistor Tr1
1, Tr12 and the transistor Tr18 are turned on, the piezoelectric element B shown in FIG. 16 is grounded, a voltage of 200 V is applied to the piezoelectric element A via the resistor Ra and the transistor Tr12, and the capacitor of the bimorph piezoelectric element Bi1 The charge is accumulated in the component CBi and the capacitor C3 provided in parallel with the component CBi, and the charging voltage increases, the bimorph piezoelectric element Bi1 bends over time, and the shutter opens. Here, the capacitor C3 regulates the magnitude of the amount of displacement with respect to time caused by the small capacity of the capacitor component CBi of the bimorph piezoelectric element Bi1.

Then, the applied voltage to the bimorph piezoelectric element Bi1 is 200 V
And the bimorph piezoelectric element Bi1 keeps this state. Here, if the predetermined amount of exposure is reached before the applied voltage to the bimorph piezoelectric element Bi1 reaches 200 V, the transistor Tr
11.Turn off both Tr12 and then turn off transistor Tr17
By setting it to N, both ends of the bimorph piezoelectric element Bi1 are short-circuited and the shutter is closed. This closes the shutter and ends the exposure, but the shutter does not return to the initial position due to the hysteresis and characteristics of the bimorph piezoelectric element Bi1.

Therefore, a reverse voltage is applied to the bimorph piezoelectric element Bi1 to return it to the initial position. For this purpose, the transistor Tr18 is turned off and the transistors Tr19 and Tr20 are turned on.
Thus, the voltage of the piezoelectric element B becomes higher than that of the piezoelectric element A. However, if a voltage is suddenly applied to the bimorph piezoelectric element Bi1, it bends too much in the opposite direction, so that the resistor Rd is connected to the collector of the transistor Tr20 and the bimorph piezoelectric element Bi1.
Between the piezoelectric element B and the piezoelectric element B. Thus, the voltage is gradually applied to the bimorph piezoelectric element Bi1, and the bimorph piezoelectric element Bi1 is bent in the opposite direction. Then, when the shutter is returned to the initial position (this is detected by the switch provided at the initial position), the transistors Tr19, Tr20, and Tr17 are turned off to stop applying any more voltage. . This operation is performed for each photographing.

What regulates the current to the bimorph piezoelectric element Bi1 is a combination of the transistors Tr11, Tr12 and the resistor Ra, a combination of the transistors Tr13, Tr14 and the resistor Rb,
And the combination of the transistors Tr15 and Tr16 and the resistor Rc, and the aperture characteristic of the shutter can be changed by selecting which transistor.

Next, the optical system of the camera will be described with reference to FIGS. Tables 1 and 2 show the specifications of the lens group shown in FIG. 17, and Table 3 shows the specifications of the lens group shown in FIG.
It is shown in Table 4.

The aspherical shape X (y) and the reference spherical shape Xo (y)
Are defined by the following equations, respectively.

Here, r: reference radius of curvature of the aspheric surface, ε: quadratic surface parameter, Ai: coefficient of the aspheric surface, r: paraxial radius of curvature of the aspheric surface (1 / r)
= A _{(1 / r) + 2A 2} .

Fig. 19 shows the characteristics of soft shooting with the former lens group.
The characteristics in the case of normal shooting are shown in FIG. 20 and will be described below with reference to these. FIG. 19 shows only the case of telephoto, and the case of wide and middle is the same as FIGS. 20 (a) and (b). In the normal shooting state, the aperture (FNo.) Is 3.5 to 8.0 from the wide end to the tele end, and the aperture is used as open. However, when the soft mode is selected, the aperture (FNo.) Is larger than the aperture normally used at the tele end. In addition, the open side is used. At that time, the marginal spherical aberration was corrected to the extreme over side so that the image fell in love with the software. Of course, the aberrations other than the spherical aberration at this time must be the same as the aberration correction in the state of the aperture which is usually used.

In this example, the soft effect is obtained by correcting the shape of the spherical aberration toward the over side, but the same effect can be obtained by correcting the shape toward the under side. It should be noted that such a configuration can be employed at the middle or wide end instead of providing such an effect only at the telephoto end. However, in the case of soft shooting, performing at the telephoto end is more beautiful and beautiful.

FIG. 21 shows the characteristics of the latter lens group. Here, a case where the aperture diameter is changed will be described. Usually, the range shutter type camera is designed so that the open aperture diameter at each zoom position is constant. SLR (SL
R) In cameras, etc., this open aperture diameter is variable, so a cam etc. for determining the aperture diameter is required,
The structure becomes complicated and leads to an increase in cost. Therefore, in a lens shutter type camera, the open aperture diameter is fixed. However, for that purpose, the aperture (FNo.) At each position is determined according to the zoom ratio, which is a great constraint on optical design.

Therefore, by making the aperture diameter variable, for example, by darkening the F No. on the wide side than normal, it becomes possible to configure a zoom lens with a smaller number of lenses, and also, the axial light beam width Is reduced, so that the off-axis illuminance ratio is also improved. For this reason, the optical system can compensate for a decrease in the amount of peripheral light of the flash, which is a problem at the wide end or the like. Conversely, by increasing the F No. on the tele side, the reach of the flash can be further increased. Against this background, in the example shown in FIG. 19, the wide-side FNo.
o. is a brighter zoom lens.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a camera to which the present invention is applied,
FIG. 2 is a diagram showing a distance measurement range of the camera, FIG. 3 is a diagram showing a shutter control program line of the camera, and FIGS. 4 (a-1) and (a-2) are shutter drive waveforms in the standard mode. FIG. 4 (b-1) and FIG. 4 (b-2) are diagrams corresponding to the above in the sports mode, and FIG. 4 (c-
1) (c-2) is a view corresponding to the above in the commemorative photo mode, FIGS. 4 (d-1) and (d-2) are views corresponding to the above in the soft photo mode, and FIG. FIG. 6 is a flowchart of mode switching,
FIG. 7 is a flowchart of photometry and distance measurement, FIG. 8 is a flowchart for determining an exposure value and a distance, FIG. 9 is a flowchart of exposure, FIGS. 10 (a) and (b) are diagrams showing a ROM table, and FIG. Is a flowchart showing another example of the exposure operation,
FIGS. 12 (a) and 12 (b) are diagrams showing the relationship between the shutter opening waveform and flash emission according to each of the other examples, FIG. 13 is a circuit diagram of the flash unit, and FIGS. 14 (a), (b) and (c). ) Is a diagram showing the configuration and operation of the shutter mechanism, FIG. 15 is a shutter control circuit diagram using a bimorph element, FIG. 16 is a principle configuration diagram of the bimorph element, and FIG. 17 is a diagram showing an optical system of the present camera. FIG. 18 is a diagram showing another example of the optical system, FIG. 19 is a characteristic diagram for soft photographing by the optical system of FIG. 17, FIG. 20 is a characteristic diagram for normal photographing by the optical system, FIG. 21 is a characteristic diagram in the case of photographing by the optical system of FIG. 1 ... microcomputer, 2 ... flash unit, 4 ... shutter drive driver, M1,23 ... stepping motor, 21 ...
Shutter blade.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Naoshi Okada 2-3-3 Azuchicho, Chuo-ku, Osaka-shi, Osaka, Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Hiroyuki Okada Azuchi, Chuo-ku, Osaka-shi, Osaka 2-3-13 Machi, Osaka Kokusai Building Minolta Camera Co., Ltd. (72) Inventor Dai Shintani 2-3-13, Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka Kokusai Building Minolta Camera Co., Ltd. (72) Inventor Namba Katsuyuki 2-3-13 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd. (56) References JP-A-2-84631 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03B 7/00-7/28

Claims (1)

(57) [Claims] 1. An aperture / shutter having a variable aperture diameter and a shutter time, and a camera using a flash device, wherein a flash is emitted a plurality of times while the shutter is opened or closed. Flash emission control device.