JPH04128728A - Controller for driving shutter of camera - Google Patents

Abstract

PURPOSE:To prevent ringing at the time of stopping a shutter by providing a means for braking a motor when a stop aperture is a desired stop value, and a plunger mechanism which is driven at that time and brakes a driving mechanism. CONSTITUTION:A shutter is constituted of three shutter blades 21, a sector gear 22 in which the shutter blades 21 as the component element of a mechanism to drive the shutter blade 21 are engaged, a stepping motor 23 for driving and a reduction gear 24. Furthermore, the plunger 25 in which a magnet excited by being energized when the stop aperture reaches the desired stop value is set as a driving source, and a brake lever 26 connected with this plunger 25 to brake the sector gear 22 are provided. When the stop aperture is the desired stop value, a shutter driving motor 23 is braked, and also the shutter driving mechanism 22 is braked by the plunger mechanism 25. Thus, the ringing at the time of stopping the shutter is prevented, so that a specified stop value with high accuracy can be obtained.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a camera that uses a shutter that also functions as an aperture whose aperture aperture and shutter time are variable. The present invention relates to a shutter drive control device that applies a brake to the shutter drive control device.

[Prior Art] Conventionally, in cameras using a normal lens shutter, a stepping motor is used as a shutter drive source, and in order to stop the shutter at a predetermined opening position, the stepping motor is controlled to rotate forward → brake → reverse. something is known. Further, some shutter control devices using a bimorph element apply a reverse voltage to the bimorph element in order to accurately return the shutter to its initial position.

By the way, in the above-mentioned shutter device, it is still difficult to stop the shutter with precision, instead of automatically applying the brake when a predetermined aperture value is reached. I can't say it's enough.

In addition, recently, a shutter with variable aperture aperture and shutter time has been developed, but in such a shutter, ringing occurs when the shutter drive motor is braked to stop the shutter at a predetermined aperture value.
There is a problem that vibrations are likely to occur.

The present invention solves the above problems, and is a shutter drive control device that prevents ringing when the shutter is stopped and can obtain a predetermined aperture value with high accuracy in a camera that uses a shutter that also functions as an aperture with variable aperture aperture and shutter time. The purpose is to provide

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a shutter for a camera that has a motor and a drive mechanism for driving the shutter, and uses an aperture-cum-shutter with variable aperture aperture and shutter time. means in the drive control device for applying a brake to the motor when the aperture diameter reaches a desired aperture value;
The plunger mechanism is driven at that time and applies a brake to the drive mechanism.

[Operation] In the above configuration, when the aperture diameter reaches a desired aperture value, the shutter drive motor is braked, and the plunger mechanism is activated to brake the shutter drive mechanism. This prevents ringing when the shutter is stopped.

[Effects of the Invention] As described above, according to the present invention, when the aperture diameter reaches a desired aperture value, a brake is applied to the shutter drive motor, and a brake is also applied to the shutter drive mechanism by the plunger mechanism. Therefore, ringing can be prevented from occurring when the shutter is stopped, and the shutter can be stopped at a predetermined aperture value with high accuracy, and particularly small aperture accuracy can be improved.

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

FIG. 1 shows the block configuration of the circuit of this camera.

This camera uses a microcomputer (abbreviated as microcomputer)
The sequence is controlled by 1. Operation signals from switches SO to S5 are input to the microcomputer 1. When the main switch SO is turned on, the camera is activated.

The photometric and distance measuring switch S1 is turned on by pressing the release button one step. The release switch S2 is turned on by pressing the release button two steps. Zoom in switch S3,
The zoom out switch S4 is turned on and off by operating the respective zoom buttons. Mode changeover switch S
Reference numeral 5 is for switching the photographing mode, which will be described later.

The photometer AE measures the brightness of the object and sends it to the microcomputer 1. The distance measuring unit AF measures the distance to the subject and
send to Distance measurement is performed at, for example, three points in the field of view, and the range of distance measurement is from the AP in the middle of the field of view, as shown by the dotted circle in Figure 2.
2, right 1pIAF3 and left IFIAF1. The flash section 2 is connected to the microcomputer 1 via an interface IP and a fullness detection section 3. The flash unit 2 includes a high voltage circuit, a capacitor, a xenon tube, etc., and charges the capacitor and controls light emission by signals from terminals FC and TRG of the microcomputer 1 via an interface IP. Further, the charging state of the capacitor is detected by inputting a signal to the terminal RDY of the microcomputer 1 via the full charge detection section 3.

A stepping motor M1 for driving the shutter is controlled by a microcomputer 1 via a driver 4.

The stepping motor M2 for driving the lens is controlled via a dry parameter. The film winding section 6 and the zoom mechanism section 7 are connected to the microcomputer 1, and are used to wind and wind the film, respectively.
Performs rewinding and drives the zoom lens. Also, set the magnet Mg to the desired value for the shutter! This is a member for preventing ringing (vibration) from occurring when the plunger is stopped, and is a component of the plunger described later.

FIG. 3 shows the program line for controlling the shutter of this camera. In this camera, as will be described later, an appropriate program line is automatically selected based on the distance measurement result, that is, by switching the shutter start-up characteristics according to the purpose of photographing. Line ■ is for sports photography and portrait photography (sports mode)
, line ■ is for standard photography (standard mode), line ■ is for commemorative photography (commemorative photo mode or soft photo mode)
This is each program line.

The sports program line ■ is located on the higher speed side than the standard program line ■.

The program line for taking commemorative photos is located at a slower speed than the standard program line. It is used when you want to deepen the depth of field for commemorative photos, etc., and depending on the brightness, the shutter speed ranges from the maximum shutter speed of 11,500 seconds to 1/3 of the camera shake limit shutter speed.
The minimum aperture is maintained until 0 seconds. When the exposure control value Ev is 8 or less, the shutter speed is 1730 seconds,
The aperture becomes F4 and the flash fires.

FIG. 4 shows the driving waveform and aperture waveform of the shutter of this camera. (a-1) (a-2) is standard mode, (b-1) (
b-2) is the shutter drive waveform and aperture waveform of the sports mode, (C-1) and (C-2) are the commemorative photo mode, and (d-1) and (d-2) are the soft photo mode.

As shown in the figure, in the sports mode, the pulse width of the shutter driving stepping motor is made shorter than in the standard mode, and the aperture waveform has steep rises and falls. In the commemorative photo mode, the number of driving pulses is set to one pulse, and the aperture is set to open only up to, for example, F22. In the soft photography mode, the driving pulse width is long when the initial aperture is small, and becomes shorter as the aperture becomes larger. Therefore, the aperture waveform starts out with a rising edge and gradually becomes steeper.

When the shutter is closed, the opposite is true; the fall is steep at first and gradually becomes slower. Note that the stepping motor here is a case of two-phase drive, and the respective shutter drive pulse waveforms are shown divided into upper and lower parts.

FIG. 5 is a flowchart showing the operation of this camera.
This will be explained below with reference to the same figure.

When the battery is loaded into the camera, first, it is determined from "5TART" whether the main switch SO is ON or OFF (step #1). If the main switch SO is ON, the photometry and distance measurement switch S1 is determined (# 2), switch S1
If it is ON, proceed to the photometering and distance measurement routine, and if it is OFF, determine the zoom-in switch S3 (#3).
Hereinafter, the zoom out switch S4 and the mode changeover switch S5 are judged in the same way (#4 and #5), and if the switch is ON in either judgment, "zoom in", "zoom out", 'mode change' is selected. If all switches 81 to S5 are OFF, the state of charge of the capacitor for flash emission is determined (#6
). When charging is complete, that is, flash emission is possible, the voltage increase is stopped (#9), and then the process returns to #1 and the above operations are repeated. Also, main switch SO is OFF with #1.
If so, stop boosting the pressure (#8) and then return to #1.

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

This camera has five shooting modes. That is, the aforementioned I! These are semi-mode, sports mode, commemorative photo mode, soft photo mode, and fantasy mode. Fantasy mode is an effect similar to a soft filter or a zooming effect between exposures by driving the focusing lens during exposure.

"Mode switching" allows you to switch between six modes, including the five shooting modes described above and the auto program mode described below. Each time you press the mode selection switch S5, the The modes change sequentially: program mode → standard mode → sports mode → commemorative photo mode → soft mode → fantasy mode.

The auto program mode is a mode that automatically switches between the aforementioned standard mode, sports mode, and commemorative photo mode based on the distance measurement result of the subject distance. "Zoom in" and "zoom out" are routines for switching focal lengths.

FIG. 7 shows a flowchart from photometry and distance measurement to release.

In the “photometering and distance measurement” routine, first, the boost of the flash is stopped (#11), then photometry and distance measurement are performed.
2, #13), the control exposure value and distance are determined (described later) based on the photometric distance measurement results (#14), and the voltage of the capacitor for flash emission is determined (#15). If it is necessary to boost the voltage, start boosting the voltage (#16), then check the main switch S0 and photometering and distance measurement S1 (#19.#2).
0), if the switch SO or SL is OFF here, the process returns to the above-mentioned "5TART". If both switches are ON, return to #15 and repeat the above, #15
If the voltage level of the capacitor for flash emission has reached a predetermined level, stop the voltage increase (#17), and perform 0N10FF determination of the release switch S2 (#18).
). If it is OFF, proceed to #19 and repeat the above-mentioned operation. If it is ON, drive the lens according to the distance determined in #14 (#21), drive the shutter, and perform the exposure described below (#22>. When the exposure is completed, reset the lens (#23), and remove the film. Wind up (#
24), return to “5TART”.

FIG. 8 shows a flowchart for determining the exposure value and distance described above, which will be explained below.

First, the AFL on the left side of the field obtained by the above-mentioned distance measurement,
Central AP2. Compare the data of right AF3 #101)
, the closest data is set as the control distance (#102). Next, check whether the shooting mode is auto 10 duram #103
), #10 if auto program is not selected
Proceeding to step 6, a control exposure value is determined based on the subject brightness and film sensitivity obtained by the photometry described above.

If the auto program is selected in #103 above, proceed to #104 and compare the farthest data of the three distance measurement data with the latest data, and if the difference is greater than 4 zones, the subject is close. It is determined that the subject is far away, and a program line narrowed down to increase the depth of field, that is, a commemorative photo mode is selected (#105). #10
If the zone difference that cannot be determined in step 4 is O, the depth of field can be shallow because all the objects are at approximately the same distance, so a program line with a high shutter speed (SS), that is, sports mode, is selected ( #108). At that time, that is, when the zone difference is greater than or equal to 1 and less than or equal to 4, the standard mode is selected (#109). After that, #106
The exposure value is determined at , and the exposure value and distance determination routine is completed.

FIG. 9 shows a flowchart of the exposure operation.

In this routine, the shooting mode is first determined (#201.#216.#219.#222), and when it is standard mode, it goes to #202, when it is sports mode or fantasy mode, it goes to #217, and when it is in commemorative mode, it goes to #217. When in photo mode #
Proceed to #220, or #223 when in soft mode. Then, the shutter opening pulse number of the shutter blade and the stop time are read from the ROM table shown in Fig. 10 <b) (#202. #217. #220. #223).
), then the ROM address changes from OOH to 0 depending on the mode.
3H, and proceed to #204.

OOH to 03H set here are addresses in each mode of the ROM table shown in FIG. 10(a) for obtaining the drive pulse width of the stepping motor M1 for driving the shutter.

Here, regarding the number of open pulses and stop time mentioned above, the first
This will be explained using FIG. 0(b). This figure is an example of a ROM table for determining the shutter opening pulse number and 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 in the shutter opening direction for 2 pulses, then pauses for 2 mS, and then sends the stepping motor M1 in the shutter closing direction for the same amount of pulses as before. return.

If it is 8Ev, 6 pulses will be sent, 30m5 pauses, and 6 pulses will be returned. By adopting this control method,
Even with the same control value, the shutter speed and aperture value can be changed by changing the number of pulses and stop time. Note that when the shutter reaches a predetermined aperture value, the plunger is activated to prevent ringing from occurring.

FIG. 10(a) is a table of pulse widths of shutter drive pulses. In the upper bits, the 0 column is the standard mode pulse width, the 1 column is the sports and fantasy mode pulse width, the 2 column is the small aperture mode pulse width, and the 3 column is the soft mode pulse width. . 0.1.2... on the lower bit side correspond to the first pulse, second pulse, third pulse... of the shutter opening pulse, respectively.

To explain the soft mode as an example, suppose that the number of shutter opening pulses and the stop time determined by the shutter control value are 5 pulses and 4 mS, respectively. 10mS
Drive with a pulse width of Next G, second pulse 8mS,
The shutter is driven according to the value in the ROM table for the third pulse of 6 mS, and after a pause of 4 mS, the ROM table is then referred to in the opposite direction from when the shutter shutter was opened, and the shutter is closed. I do.

As described above, by changing the shutter drive pulse left E shutter opening pulse number and stop time, the rise and fall characteristics of the shutter can be changed and various opening waveforms can be obtained.

Returning to FIG. 9, the explanation will be continued. In R204, the stepping motor M1 for shutter driving is sent by one pulse in the opening direction.Next, it is determined whether the shutter driving has finished for the number of opening pulses (R205), and if not, the above-mentioned Read the pulse width (1206), wait for the time to elapse (R207), and once the time has passed, return to R204 and repeat the above operation. When the stepping motor M1 has been driven by the number of opening pulses mentioned above, proceed to R208. ,
Determine whether the shooting mode is fantasy mode or another mode. In the fantasy mode, the AP lens is driven near or far by a predetermined number of steps.
209>, proceed to R210. In R210, read the stop time, and then wait for the time to elapse (R211).
Then, close the shutter in the opposite way to opening the shutter (
#212 to #215>.

FIG. 11 shows a flowchart of exposure operation according to another embodiment. This example shows the case of flash photography in sports mode, and the operation until the shutter is opened for a predetermined number of pulses is the same as in the flowchart of FIG. 10. Same as mode. After releasing the prescribed pulse,
9 Next, start driving the zoom lens in the short focus direction (R310), then fire the flash every 0.1 seconds until the stop time ends (#311.# 312. #313). When the stop time ends, the shutter is driven in the closing direction, contrary to the opening of the shutter, to close the shutter.

By controlling as described above, it is possible to take a photograph that combines zooming and multiple flashes between exposures.

FIGS. 12A and 12B show shutter opening waveforms and flash emission timings according to yet another embodiment.

In both cases, the flash is emitted multiple times during the opening/closing operation of the shutter, and Fig. 12(a) shows the rising edge of the shutter in the opening direction. The flash fires twice. The aperture starts out small and gradually opens each time the flash fires. Therefore, in multiple flashes, the object exposed first appears darker, and the object exposed later appears brighter. Fig. 12(b) is the opposite of Fig. 12(a), in which the falling edge of the shutter in the closing direction is indicated by the arrow, and the flash is periodically emitted multiple times during the drive in the closing direction. The darker the image appears, the darker it appears. Therefore, when the subject is moving, the former allows for fade-in photography in which the subject gradually appears, and the latter enables fade-out photography in which the subject gradually disappears.

FIG. 13 shows the circuit configuration of the flash unit 2.

The circuit boosts the power supply voltage Vcc and the main capacitor C
3, a constant voltage generating circuit 12, a trigger circuit 13 for exciting the flash discharge tube Xe, a light emission control circuit 14, etc.

The DC-DC converter 11 includes an oscillation transistor Ql,
Switching transistor Q6. Q7, resistance R1, R2
, R18, R19, R20, R21, oscillation transformer T1
, and a diode D5. The oscillation transformer T1 includes a primary winding P, a secondary winding 31, 32, and an auxiliary winding F, and a main capacitor C3 is connected to the secondary winding S1 via a rectifier diode D3. As a result, the power supply voltage Vcc is boosted, and after being rectified by the diode D3, the main capacitor C3 is charged.

The main capacitor C3 is connected to the flash discharge tube Xe via a trigger circuit 13 that excites the flash discharge tube Xe, a delay circuit consisting of a coil L and a diode D4, and a terminal Z for charging completion detection.
Resistor R22 and Zener diode ZD connected to DI
2! There are pillows.

By inserting a delay circuit, the main capacitor C3
This prevents the charge from rapidly moving from the flash discharge tube Xe to the flash discharge tube Xe, and it is possible to reduce the amount of light emitted from being exceeded due to delays in the microcomputer 1 and the like.

The trigger circuit 13 is composed of a capacitor C4, a resistor R4, and a transformer T2. Secondary winding 13 of oscillation transformer T1
2, a constant voltage generation circuit [
12 are connected. This constant voltage generation circuit 12 is a circuit that supplies a constant voltage to the light emission control circuit 14 controlled by the microcomputer 1, and includes a transistor Q2 whose collector is connected to the cathode of a diode D2, and whose cathode is connected to the base of the transistor Q2. A Zener diode ZDI whose anode is grounded, a resistor R3 connected between the collector and base of the transistor Q2, and a capacitor C2 connected to the emitter of the transistor Q2 and serving as a driving power source for the light emission control circuit 14. has been done.

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, resistor R8
~R17.

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 the voltage required to cause the flash discharge tube Xe to emit light,
2 is designed to be charged to the voltage required to drive the IGBT.

In FIG. 13, when terminal FCO is set to "L", transistor Q7. Q6. When Ql is ONL, the DC-DC converter 11 starts operating and the capacitor C3 is charged. Further, power is supplied from the secondary winding S2 to the constant voltage circuit 12, which operates, and power is supplied to the light emission control circuit 14, thereby entering the Fra-Souche light emission preparation state. 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, transistor Q8. Q5. Q4 is ONL, resistor R8
A voltage is applied to the gate of the IGBT via the IGBT, and the IGBT is turned on. As a result, a current flows through the primary winding of the transformer T2 to charge the capacitor C4, a trigger pulse is generated from the secondary winding of the transformer T2, and the flash discharge tube Xe emits light due to the discharge of the main capacitor C3. Start.

After that, when the terminal TRGO is pulled up to "H", the transistor Q3 turns ON, and the transistors Q8, Q5, . Q4 turns OFF. When transistor Q3 turns on, IGBT
The gate of the IGBT is grounded and the IGBT is turned off. As a result, no discharge current flows to the flash discharge tube Xe, and light emission stops. Transistor Q8. Q5. When Q4 is turned off, it is possible to prevent capacitor C2 from discharging via transistor Q4, resistor R8, and transistor Q3.

By controlling the terminal TRGO at an appropriate timing as described above, an arbitrary flash emission intensity can be obtained. Continuous flash emission is also possible.

FIG. 14 shows an example of the shutter m-ellipse of this camera. This shutter is an aperture shutter with variable aperture aperture and shutter time, and its configuration and operation will be explained below.

This shutter includes three shutter blades 21, a sector gear 22 that is engaged with the shutter blades 21 as a component of a mechanism for driving the shutter blades 21, and a driving stepping motor 23 (Ml in FIG. ), a reduction gear 24, and a plunger 25, which is driven by a magnet Mg that is excited by electricity when the aperture diameter does not reach the desired aperture value, and the plunger 2.
5 and a brake lever 26 that applies a brake to the sector gear 22. 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-open state of FIG. 14(c), the reduction gear 24 rotates counterclockwise, and the sector gear 22 rotates clockwise. The shutter blade 21 is rotatably supported by a shaft 21a on a substrate (not shown).
A pin 22a of the sector gear 22 is fitted into the pin 1b.

Therefore, the shutter blade 21 rotates counterclockwise in accordance with the rotation of the sector gear 22, and the shutter opens and enters the exposure state.

When the shutter reaches a desired aperture value, the stepping motor 23 is brought into a braking state and current is supplied to the plunger 25, causing the brake lever 26, which is connected at one end to the plunger 25, to rotate at the other end. It starts rotating clockwise around the shaft 26a and comes into contact with the sector gear 22. This makes it possible to reliably apply a brake to the shutter drive mechanism, prevent ringing from occurring, and obtain a desired aperture value 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).

Note that FIG. 2A shows the shutter opening. In this case, since the open aperture value is determined by the opening of the sector gear 22, there is no need for braking using the lever 26.

In the above, an example in which the stepping motor 23 is used to drive the shutter has been described. Next, an example in which a bimorph piezoelectric element is used to drive 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 the basic structure of the bimorph piezoelectric element. As shown in FIG. 16, the bimorph piezoelectric element Bil has a structure in which a metal substrate is sandwiched between piezoelectric elements A and B, and when a voltage is applied to one piezoelectric element to the other piezoelectric element, the bimorph piezoelectric element Bill bends. This force is used to drive the shutter blades.

The shutter control circuit shown in FIG.
1 to Tr5, resistor R1, and DC-DC converter (D
A booster circuit 31 consisting of C-DC) and a capacitor C2,
C3, pressure detection circuit BCI, transistors Trll~T
r 20, and an exposure control circuit 32 consisting of a bimorph piezoelectric element Bil.

The boosted voltage is taken out from the secondary winding of the DC-DC converter (DC-DC), and the voltage v3 is supplied to the exposure control circuit 32 via the diode D3. The exposure control circuit 32 includes a capacitor C2 that stores charge, a voltage detection circuit BCI that detects the voltage stored in the capacitor C2, a bimorph piezoelectric element Bit, and a capacitor C3 connected in parallel to the bimorph piezoelectric element Bi1. , control transistors Trll to Tr20.

In the above configuration, the voltage detection circuit BCI outputs an "H" level detection signal to the input terminal IP3 of the microcomputer 1 when it detects 200. By inputting this signal, the microcomputer 1 turns off the boost control transistor of the boost circuit 31 and stops boosting. Next, the operation of the control transistors Trll to Tr20 that apply the voltage thus obtained to the bimorph piezoelectric element Bil will be explained.

The collector side of the transistor Tr18 of the bimorph Bil corresponds to the piezoelectric element B in FIG.
If N, the piezoelectric element B shown in FIG. 16 is grounded, a voltage of 200 μ is applied to the piezoelectric element A via the resistor Ra and the transistor T r 12, and the bimorph piezoelectric element B
Electric charge is accumulated in the capacitor component CBL of il and the capacitor C3 provided in parallel thereto, and the charged tt pressure thereof increases, and the bimorph piezoelectric element Bil curves over time and the shutter opens.

Here, the capacitor C3 regulates the amount of displacement with respect to time that occurs because the capacitance of the capacitor component CBi of the bimorph piezoelectric element Bil is small.

Then, the voltage applied to the bimorph piezoelectric element Bil is 20
0■, and the bimorph piezoelectric element Bil maintains this state. If the predetermined exposure amount is reached before the voltage applied to the bimorph piezoelectric element Bil reaches 200■, both transistors Trll and Tr12 are turned off. , and then by turning on the transistor Tr17,
Both ends of the bimorph piezoelectric element Bil are short-circuited and the shutter is closed. As a result, either the shutter is closed and the exposure ends, or the shutter does not return to its initial position due to the hysteresis characteristic of the bimorph piezoelectric element Bi1.

Therefore, a reverse voltage is applied to the bimorph piezoelectric element Bil in order to return it to its initial position. For this purpose, the transistor T r 18 is turned off, and the transistor T
Turn on r 19 and T r 20 so that the voltage of piezoelectric element B becomes higher than that of piezoelectric element A. However, if a voltage is suddenly applied to the bimorph piezoelectric element Bil, it will bend too much in the opposite direction, so a resistor Rd is inserted between the collector of the transistor Tr20 and the piezoelectric element B of the bimorph piezoelectric element Bil. In this way, a voltage is gradually applied to the bimorph piezoelectric element Bil to bend it in the opposite direction. Then, when the shutter is returned to the initial position (this is detected by a switch provided at the initial position), transistor Tr19. Tr20. Tr17 each OF
F and stop applying any more voltage. This operation is performed every time a photograph is taken.

The current flowing to the bimorph piezoelectric element Bil is regulated by the combination of the transistors T r 11 and T r 12 and the resistor Ra, and the transistors Tri3 and Tr1.
4 and the resistor Rb, and the transistor Tr1
5. It is a combination of Tr16 and resistor Rc, and the aperture characteristics of the shutter can be changed by selecting which transistor.

Next, the optical system of this camera will be explained using FIGS. 17 to 21. The specifications of the lens group shown in FIG. 17 are shown in Tables 1 and 2, and the specifications of the lens group shown in FIG. 18 are shown in Tables 3 and 4.

Note that the aspherical shape X (V) and the reference spherical shape X.

(y) are each defined by the following formulas.

21/2 X(V)=(r/ε)(1-ε・y”/r))+ΣAi
y' ≧2 2 1/2 Xo(y) =r ・(1-t (y2./r
) Here, r: standard radius of curvature of the aspherical surface, ε
: quadratic surface parameter, Ai: aspheric coefficient, r: paraxial radius of curvature of aspheric surface < 1, / r > = (1/ r
) +2 A 2.

Figure 19 shows the soft shooting characteristics of the former lens group.
The characteristics in the case of normal photography are shown in FIG. 20, and will be explained below with reference to these. Figure 19 shows only the case of telephoto, and the case of wide and middle is shown in Figure 20 (a) (b).
) is the same as 0. In normal shooting conditions, the aperture (FN
o. ) is used as an aperture of 3.5 to 8.0 from the wide end to the telephoto end, but when the soft mode is selected, the aperture is further opened than the normally used aperture at the telephoto end. At that time, the marginal spherical aberration is corrected to the extreme side so that the image appears soft. Of course, at this time, aberrations other than spherical aberration must be the same as the aberration correction of the normally used aperture state.

Further, in this example, a soft effect is obtained by correcting the shape of the spherical aberration to the over side, but a similar effect can also be obtained by correcting it to the under side. Note that instead of creating this effect only at the telephoto end, you can also use this configuration at the middle or wide end, but for soft shooting, the effect will be more dramatic and beautiful if done at the tele end.

The characteristics of the latter lens group are shown in FIG. Here, we will explain the case where the aperture diameter is changed.Normally, a lens shutter type camera is designed with the open aperture diameter constant at each zoom position. -Eye reflex (SL)
R) In cameras, etc., the aperture diameter is variable, so a cam etc. is required to determine the different diameter.
The structure becomes complicated and costs increase.

Therefore, in a lens shutter type camera, the aperture diameter is kept constant. However, for this reason, the aperture at each position is determined according to the zoom ratio, which is a major constraint on optical design.

Therefore, by making the open aperture diameter variable, for example, by making the FNo. on the wide side darker than usual, it becomes possible to construct a zoom lens with fewer lenses, and also to increase the axial luminous flux width. Since this decreases, the off-axis illuminance ratio also improves. Therefore, it becomes possible for the optical system to compensate for the decrease in peripheral light intensity of the flash, which is a problem at the wide end.

Conversely, by making the FNo. on the telephoto side brighter, it is possible to make the flash reach farther. Against this background, the example shown in FIG. 19 is a zoom lens in which the FNo on the wide side is darker and the FNo on the telephoto side is brighter than in the case of a normal fixed aperture diameter.

Table 1 f=39.3~58.5~Ki, 6 FNo.=3.5 curvature radius 23.799 dl 281.900 d2 -18.355 d3 -103.438 d4 28.346.1s -16,057d6 Peep, 985 dl peek, 892 d8 -10.697 dg -37,458 Shaft top surface spacing 1.800 1.400 i,oo.

4.675 3.650 11.961~7.209\Book 040 4.000 6.000 1.044 Refractive index (Nd) N1 1.51680 1.7755+ 1.51680 1, 71736 1.75450 Atsube 4th order (νd) ν1 64.20 37.90 Nod, 20 29.42 51.57 Σd=Ah, 53° Table 3 f=A, 2~53.0~77.5 FNo.=4.5 curvature radius 28.708 dl 12.092 d2 words, 481d3 -10.838 d4 -29.336 d5 -20.652 d6 -10.486 dl -31,800 Shaft top surface spacing 2.3 GO 3,819 4,200 13,968~7.950~3.8503.680 4.768 1.000 Refractive index (Nd) N1 1.58340 1.49300 1.49300 1.72000 Atsbe number (νd) ν1’ 30.23 58.34 50.37 Σd=4.735

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of a camera to which the present invention is applied;
Figure 2 shows the distance measurement range of this camera, Figure 3 shows the shutter control program line of this camera, and Figure 4 (
a-1) (a-2) is a diagram showing the shutter drive waveform and aperture waveform in standard mode, Figure 4 (b-1) (b-2)
is a diagram corresponding to the above in sports mode, Figure 4 (c-
1) (c-2> is a diagram corresponding to the above in commemorative photo mode, Figure 4 (d-1) (d-2> is a diagram corresponding to the above in soft photo mode, Figure 5 is a diagram corresponding to the above in commemorative photo mode) Figure 6 is a flowchart for mode switching, Figure 7 is a flowchart for photometry and distance measurement, Figure 8 is a flowchart for determining exposure value and distance, Figure 9 is a flowchart for exposure, Figure 10 ( a) and (b) are diagrams showing a ROM table, FIG. 11 is a flowchart showing another example of exposure operation, and FIG. 12 (a>(b) is a relationship between the shutter aperture waveform and flash emission according to other examples, respectively) Figure 13 is a circuit diagram of the flash section, Figure 14 <a) (b)
(C) is a diagram showing the configuration and operation of the shutter mechanism, Figure 15 is a shutter control circuit diagram using a bimorph element, and Figure 16 is a diagram showing the configuration and operation of the shutter mechanism.
The figure shows the basic configuration of the bimorph element, Figure 17 shows the optical system of this camera, Figure 18 shows an example of the optical system, and Figure 19 shows software photography using the optical system shown in Figure 17. FIG. 20 is a characteristic diagram for normal photographing using the same optical system, and FIG. 21 is a characteristic diagram for photographing using the optical system shown in FIG. 1...Microcomputer, 4...Shutter drive driver, M
l, 23...Stepping motor, 21...Shutter blade, 22...Sector gear, 25...1 lungier 26...Brake lever Applicant Minolta Camera Co., Ltd. Agent
Patent Attorney Yasushi Itatani Fire Brother 7 Medical Diagram Diagram ROM Table Shutter Drive Pulse Width (mS) Country Diagram TRG. : Figure 1 (a) Figure (C) Figure (b) Figure (a-1) (a-2) (a-3) Y'-21,63 Y'-21,63 Happy 20 Figure Y'-21, 63 Spherical rough sine 1 case, ? I, Jl艮入Y', 21.63 Hmc't. Macen Station Vine Sine Condition Spherical Water Difference Sine To Case Diagram Astigmatism, Hamabun 1 4L Curve oI.

Claims (1)

[Claims] (1) In a camera that has a motor and a drive mechanism that drives the shutter, and uses a shutter that also functions as an aperture with variable aperture aperture and shutter time, when the aperture aperture reaches a desired aperture value, the motor A camera shutter drive control device comprising means for applying a brake, and a plunger mechanism that is driven at the time and applies a brake to the drive mechanism.