JP2002072313A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera which can reduce as much as possible a variation (an interrupted point) in a total operation finishing time caused by changing over a driving method in a camera of which the plural motors share driving of the mechanisms in the camera. SOLUTION: A power supply checking circuit 54 and a temperature detection circuit 55 detect a power supply use condition and a use environment temperature, respectively, and based on the results, it is changed over whether to simultaneously drive necessary motors 21, 22 and 23 in the same sequence period, or to sequentially drive a part of them 22, 23. Further, at least one motor-driven system mechanism 41 can be switched to the setting of plural reduction ratios by a change-over mechanism 36, the reduction ratios are also changed over synchronizing with simultaneous/sequential changeover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to a camera that uses a plurality of motors to drive a mechanism in the camera.

[0002]

2. Description of the Related Art Conventionally, various cameras have been proposed in which a plurality of motors are used to drive a mechanism in the camera.

For example, Japanese Patent Laying-Open No. 62-89938 proposes a camera having a camera operation mechanism that uses a motor as a drive source and can switch between two transmission systems having different reduction ratios. When the drive speed of the drive target falls below the determination speed, the camera determines that the drive speed is abnormally low, and switches from the reduced speed ratio transmission system to the high reduction ratio transmission system. Further, the state of switching to the high reduction ratio transmission system is maintained at least until film winding of all frames is completed, and after the completion of rewinding, the transmission system is returned to the reduced speed ratio transmission system.

Japanese Patent Application Laid-Open No. 1-210940 discloses that a film winding operation and a shutter charging operation are performed by a dedicated motor, a film winding speed is detected, and both motors are driven simultaneously or sequentially. A camera has been proposed in which the number of films that can be photographed is increased by making a determination without replacing the battery.

Japanese Patent Application Laid-Open No. 8-286247 has a plurality of motor mechanisms for sharing and driving the film and film feeding, and voltage detecting means for detecting a power supply voltage. There has been proposed a camera that selects an optimum time from a plurality of delay times that shift the start time of charging and film feeding according to the voltage level detected by the means. In this case, a rush current corresponding to the starting current flows because the motor is in a transient state of being accelerated for a while after the power is supplied to the motor. If the energization of a plurality of motors is started during this transition state, a plurality of rush currents will be required, which may temporarily hinder the power supply capability. It is effective to shift the energization start time of the motor against this phenomenon, but under bad conditions (described above), the difference between the required current and the starting current of the motor becomes small. The method alone is not enough.

[0006]

When one frame photographing mechanical operation of a single-lens reflex camera is to be performed by an electric motor, a plurality of operations must be performed in the same period. Specifically, “focus adjustment” and “aperture adjustment” are performed as pre-exposure preparation operations.
“Retract mirror”, “release shutter lock”, and “exposure return”, “mirror return”, “shutter mechanism charge”, and “film wind” are performed as post-exposure operations. In order to reduce the operation time of one frame photographing, it is often performed to perform a plurality of operations before and after the exposure at the same time.

When a plurality of operations are simultaneously driven with a design assuming independent operation of each operation, the load torque becomes larger than the generated torque of the motor under a bad condition such as a power-down state or a load increase state. Inability to drive can occur. Therefore, it is common practice to set the motor so that it can be driven even under adverse conditions such as a power supply drop or a load increase, and to reduce the required energy per unit time (motor current). Had become. In other words, if the operation time under normal favorable conditions is to be shortened, the number of films that can be photographed without replacing the battery will decrease.

In order to solve this problem, a method has been proposed in which a plurality of operations are performed simultaneously under favorable conditions, and the plurality of operations performed simultaneously are sequentially switched to operations under bad conditions (for example, Japanese Patent Application Laid-Open No. HEI 9-110572). JP-A-11020940). As a result, under a favorable condition, a relatively large current is used to realize a short-time operation, and under a bad condition, a required current is dispersed in a time-series manner so that operation can be guaranteed even with a power supply having a reduced current supply capability.

However, there is a disadvantage that a total operating time greatly changes before and after switching between simultaneous driving and sequential driving.

In addition, the detection result of the speed of the driving member is used for discriminating the favorable condition / bad condition. In this case, it is necessary to obtain speed data after driving in advance, or to start driving once to obtain speed data and then switch the driving sequence, which complicates the determination sequence. Although the detection result during the previous driving can be used as the advance data, it cannot be correctly determined that the condition has changed significantly between the previous time and the current time.

On the other hand, one motor drive mechanism has two different reduction ratio mechanisms, and by switching between them, it is possible to reduce the operating time and reduce the number of films that can be photographed without replacing batteries. A method has also been proposed which makes the "increase" compatible (for example, the above-mentioned Japanese Patent Application Laid-Open No. 62-89938).

[0012] In this case as well, there is a disadvantage that the total operating time greatly changes before and after the reduction ratio switching.

Further, the result of detecting the speed of the driving member is used for discriminating between favorable conditions and bad conditions. In this case, it is necessary to obtain speed data after driving in advance, or to start driving once and obtain speed data, and then switch the drive sequence, and the sequence is complicated, such as when the reduction ratio is switched during the shooting operation. become.

Accordingly, a technical problem to be solved by the present invention is to minimize the variation (breakpoint) of the operation end time of each mechanism due to switching of the driving method in a camera in which a plurality of motors share the drive of the mechanism in the camera. It is to provide a camera that can be made smaller.

[0015]

SUMMARY OF THE INVENTION The present invention provides a camera having the following configuration to solve the above technical problems.

The camera has at least three first, second and third drive sources which receive power supply from one power source,
It is of a type for driving at least three different first, second and third driven members, respectively. The camera includes first and second drive systems, a drive system switching unit, a drive condition detection unit, and a control unit. One of the first and second drive systems transmits a driving force so as to be switchable from the first drive source to the first driven member. When transmitting a driving force from the first driving source to the first driven member, the first driving system may control a relative power supply amount per unit time from the power source to the first driving source. Often. The second drive system, when transmitting a driving force from the first drive source to the first driven member,
The amount of power supply per unit time from the power supply to the first drive source is relatively small. The drive system switching unit switches between the first drive system and the second drive system, and receives a signal from the first drive source via one of the first drive system and the second drive system. The driving force is transmitted to the first driven member. The drive condition detection unit detects a drive condition of each of the drive sources. The drive condition determination unit determines whether the power supply has a margin for power supply based on the drive condition detected by the drive condition detection unit. The control unit performs the first control or the second control based on the determination of the drive condition determination unit. That is, when it is determined based on the determination by the drive condition determination section that the power supply has a margin for supplying power, the first driven source is switched to the first driven source via the first drive system. Controlling the drive system switching unit to transmit the driving force to the member,
In addition, a first control for controlling the respective driving sources is performed so that the respective driving sources are simultaneously driven. When it is determined based on the determination by the drive condition determination section that the power supply has no margin for power supply, the first driven source is connected to the first driven member via the second drive system. The driving system switching unit is controlled to transmit a driving force, and the first driving source is driven. In parallel with this, the second and third driving sources are driven.
The second control is performed to control each of the above-mentioned driving sources so that the driving sources are sequentially driven.

In the above configuration, the drive source is generally a motor, but may be another actuator. Further, the same switching is also effective when a part of the three driving sources is not an actuator but a circuit or a circuit element having relatively large power consumption (flash charging, various light sources, high-speed data processing circuit, etc.). For example, a method can be adopted in which the circuit (element) is applied to the third drive source, and simultaneous processing (drive) and sequential processing (drive) are switched according to conditions. Further, for example, the above-described circuit (element) is applied to the first drive source, and is operated in a normal operation mode (large current consumption) during simultaneous processing (drive), and is operated in a power saving mode (low processing speed during sequential processing (drive)). Or the brightness of the light source can be suppressed, so that the operation can be performed depending on the conditions so that the operation can be performed with low current consumption. Further, the drive start timings of the drive sources that are driven simultaneously or in parallel may be slightly shifted.

According to the above configuration, when there is enough power, the first control drives the three driving sources at the same time, and the driving of all the driving sources is completed in a short time. If the power supply has no margin, the second control causes
Driving the two driving sources (first and second driving sources) simultaneously,
When the driving of one (second driving source) ends earlier than the other (first driving source), the remaining driving source (third driving source) is driven. The drive sources (first drive sources) other than the sequentially driven drive sources (second and third drive sources) include two drive systems that transmit a driving force to driven members.
If there is no margin in the power supply, the driving system is switched to the driving system (second driving system) in which the power supply amount per unit time is relatively small. As a result, while the drive system (first drive system) having a relatively large amount of power supply per unit time remains, the amount of power supply to the sequentially driven drive sources (second and third drive sources) decreases. The time until the sequential driving of the two driving sources (the second and the third driving sources) ends is increased, and as a result, the time until the driving of all the driving sources ends is increased. Can be prevented.

Therefore, it is possible to minimize the fluctuation of the entire operation end time due to the switching of the driving method.

Preferably, the driving condition detecting section detects, as the driving condition, an ability of the power supply to supply power to each of the driving sources. For example, the state of the power supply itself is known by detecting the open voltage of the battery and the internal resistance of the battery.

Preferably, the driving condition detecting section detects a temperature inside the camera as the driving condition. For example, it is possible to consider the influence of a load applied to a driving source by temperature, such as a film or a lubricant in a camera.

Preferably, the first drive system has a relatively small reduction ratio, and the second drive system has a relatively large reduction ratio. When the driving force is transmitted from the first driving source to the first driven member, the power supply amount per unit time from the power source to the first driving source is larger in the first driving system, and the second driving system is in the second driving system. The load torque applied to the first drive source by the drive system can be set to be larger in the first drive system and smaller in the second drive system so that the drive system is smaller. .

Further, by switching the output characteristics of the drive source so that the amount of power supply per unit time from the power source to the first drive source is different between the first setting and the second setting, the same as the reduction ratio switching. An effect can also be obtained. Specifically, a motor that can be used by switching a plurality of winding resistance settings (see Japanese Patent No. 2780240) is used as a first driving source, and a low resistance is used in a first setting (corresponding to the first driving system). In the second setting (corresponding to the second drive system), a high-resistance winding may be used.

Preferably, when an operation of turning on a power switch of the camera is performed, the driving condition detecting unit, the driving condition determining unit, and the control unit operate. When the power switch is turned on, the driving conditions such as the temperature conditions and power supply voltage inside the camera may change due to changes in the environment around the camera or replacement of the battery. Review the driving method.

Preferably, after the drive condition determination section determines that the power supply has no margin, the determination is continued until the power switch of the camera is turned off. When the driving conditions slightly fluctuate due to the power supply and the temperature, and thereby the first control and the second control are frequently switched, the switching operation is performed each time, and the operation speed of the camera also fluctuates, and the operational feeling is reduced. Therefore, hysteresis is provided in the execution determination of the switching of the driving method, and this can be prevented.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A camera according to one embodiment of the present invention drives motors necessary for the same sequence section simultaneously or partially according to detection results of operating power supply conditions and operating environment temperatures. Switching is performed sequentially, and at least one motor drive mechanism can be switched to a plurality of reduction ratio settings, and the reduction ratio is also switched in conjunction with simultaneous / sequential switching. This will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the arrangement of the internal mechanism of the camera.

At the center of the camera body 10, a lens 80 is mounted, and the main mirror 14 is disposed so as to face the lens 80. Behind the main mirror 14, a shutter 16 and a shutter control unit 5 are provided.
3 are arranged. Around the main mirror 14, an aperture driving mechanism 43 for driving an aperture (not shown) of the lens 80 and a focus lens driving mechanism 44 for driving a focus lens (not shown) of the lens 80 are provided. Are located. A film cartridge 18 is mounted on one side of the camera body 10, and a film winding spool 12 is arranged on the other side. Adjacent to the film take-up spool 12, a film feed mechanism 41 for winding and rewinding the film of the film cartridge 18 to the film take-up spool 12 is arranged. A mirror / shutter driving mechanism 4 for driving the main mirror 14 and the shutter 16 adjacent to the film cartridge 18
2 are arranged. The aperture driving mechanism 43 is used for the aperture motor 2
3, the focus lens drive mechanism 34 is driven by the focus motor 24, the film feed mechanism 41 is driven by the feed motor 21, and the mirror / shutter drive mechanism (charge / release mechanism) 42 is driven by the charge motor 22. Has become.

FIG. 2 is a block diagram showing a system configuration of the control system.

A control circuit 50 for controlling the entire camera.
Includes a photometric circuit 51 for performing photometry, a distance measuring circuit 52 for performing distance measurement, and a shutter driving circuit 53 for driving the shutter 16.
A power supply check circuit 54 for detecting the state of the power supply; a temperature detection circuit 55 for detecting the temperature near the film path in the camera; a storage circuit 56 for storing various set values and the like; A mechanism position signal detection circuit 60 for detection, a feed motor drive circuit 61 for driving the feed motor 21, a charge motor drive circuit 62 for driving the charge motor 22, and a drive for the aperture motor 23 Motor drive circuit 63 for driving the focus motor 24 and the focus motor drive circuit 6 for driving the focus motor 24
4 and a switching element driving circuit 65 for driving the switching driving element 25 for switching the reduction ratio of the focus lens driving mechanism. Further, a main switch S0, a start switch S1, and a release switch S2 are connected to the control circuit 50. Each of the motors 21 to 24
The drive mechanisms 41 to 41 are respectively connected via the speed reduction mechanisms 31 to 34.
44 is driven. Although described later in detail, the film feeding mechanism 41 includes a reduction ratio / driven member switching mechanism 36.
And the focus lens drive mechanism 44 is
It is driven via a reduction ratio switching mechanism 38.

FIG. 3 is a timing chart showing the entire one-frame photographing sequence.

When the shutter button is half-pressed, the start switch S is pressed.
When 1 is turned on, photometry and distance measurement are performed, and the focus motor 24 is driven to perform a focusing operation.

When the release switch S2 is turned on by fully pressing the shutter button, the charge motor 22 rotates forward to release the lock between the main mirror 14 and the shutter 16. A little later than the charge motor 22, the aperture motor 23 also rotates forward to narrow the aperture of the lens 80 to a predetermined aperture. When the time from when the start switch S1 is turned on to when the release switch S2 is turned on is short, or when it is determined that the subject is a moving object, the focus motor 24 is operated even after the release switch S2 is turned on.

Next, after the front curtain 1c of the shutter is driven, the rear curtain 2c is driven to expose the film.

The conditions for starting the exposure are as follows: a predetermined time t _a has elapsed after the lock release of the main mirror 14 and the shutter 16 has been completed, and a predetermined time t _a has elapsed after the completion of the aperture-down operation.
_b has elapsed and the focusing operation has been completed.

After the exposure, first, the charge motor 22 rotates forward to charge the main mirror 14, and then charges the shutter 16 with a slight delay.

The aperture motor 23 starts reverse rotation a little after the charge motor 22, and returns the aperture of the lens 80 to the open state.

The feed motor 2 is slightly delayed from the throttle motor 23.
1 starts rotating, and feeds the film by one frame while detecting the perforation of the film.

Further, photometry / ranging is performed. The start timing is a predetermined time t after the mirror charge is completed.
_c has elapsed, and is after the lens iris 80 has returned to the open, and after the exposure, it is after the predetermined time t _d has elapsed predetermined.

The drive of the charge motor 22, the aperture motor 23, and the feed motor 21 performed for the mechanical return operation after the exposure is switched as shown in FIG.

That is, in a normal power supply state, FIG.
As shown in (a), the charge motor 22, the aperture motor 23, and the feed motor 21 are simultaneously driven. Feed motor 2
1 is driven by a high-speed drive system (Hi).

However, the timing of starting the start of the motor (start of energization) is slightly shifted. This is to prevent a rush current flowing through the motor in the accelerated state immediately after the energization from being overlapped, thereby temporarily reducing the current supply of the power supply.

When the power condition is lowered, as shown in FIG. 4B, the time required for each motor to complete its rotation becomes longer.

When the power supply condition further decreases, FIG.
As shown in (3), the driving is switched from simultaneous driving of three motors to sequential driving.

That is, the throttle motor 23 and the feed motor 2
1 are driven simultaneously. However, the start timing of the start is slightly shifted. Since the drive of the aperture motor 23 ends before the feed motor 21, the charge motor 22 is driven after the drive of the aperture motor 23.

At this time, the drive system of the feed motor 21 is changed from the high-speed drive system (Hi) having the reduced speed ratio to the low-speed drive system (Lo) having the high reduction ratio by the reduction ratio switching mechanism 36 before the film feeding is started. Switch to. This is because when the feed motor 21 is driven in the high-speed drive system (Hi), the power consumption by the feed motor 21 is large, and the power to the aperture motor 23 and the charge motor 22 is increased as shown in FIG. The supply is reduced, the time required for the rotation of the aperture motor 23 and the charge motor 22 is increased, and the end of the sequential drive of the aperture motor 23 and the charge motor 22 is delayed even if the rotation of the feed motor 61 ends early. It takes longer time to complete the driving of the motor.

On the other hand, when the feed motor 21 is switched to be driven by the low-speed drive system (Lo), the feed motor 2
1, the power supply to the aperture motor 23 and the charge motor 22 increases, and the aperture motor 23
Thus, the time required for terminating the driving of the charge motor 22 is reduced. As a result, although the drive completion of the feed motor 21 is delayed, the drive of the aperture motor 23 and the charge motor 22 which take longer time is completed earlier, and the time required to complete the drive of all the motors is shorter. Become.

That is, when the power supply condition is further reduced from the state of the simultaneous driving shown in FIG. 4B, the delay of the driving completion by the three motors is caused by the sequential driving of the aperture motor 23 and the charge motor 22 shown in FIG. when performing the speed reduction ratio switching the feed motor 21 is t _1, perform the reduction ratio switching the feed motor 21 performs only sequential switching of the drive of the diaphragm motor 23 and the charge motor 22 shown in FIG. 4 (d) If no it is t _2, a t ₁ <t _2.

Therefore, by combining the sequential driving and the switching of the reduction ratio, the fluctuation (break) of the entire operation end time due to the switching of the driving method can be minimized.

FIGS. 5 and 6 are explanatory diagrams of a mechanism for switching the reduction ratio of the drive system of the feed motor 21. FIG.

The control cam has three layers, as shown in FIG.
The first layer cam gear 110 shown in FIG. 5, the second layer first cam 112 shown in FIG. 5B, and the third layer second cam 114 shown in FIG. 5C rotate integrally. It has become. The cams 112 and 114 are connected to the engagement permission sections 112a and 1a.
14a, carrier lift sections 112b and 114b,
It has engagement prevention sections 112c and 114c. The phases of the meshing permission sections 112a and 114a are shifted by about 90 degrees.

As shown in FIGS. 5A and 5B, a first planetary gear 102 supported by a first arm 101 is attached to the sun gear 100 to which the rotation from the feed motor 21 is transmitted.
As shown in FIG. 5C, the second planetary gear 104 supported by the second arm 103 meshes with the second planetary gear 104. The first arm 101 and the second arm 103 have contact pieces 101a and 103a that contact the first cam 112 and the second cam 114, respectively.

As shown in FIG. 5A, the sun gear 100
Rotates counterclockwise in the figure, the first planetary gear 1
02 meshes with the cam gear 110 to rotate the control gear, that is, the first and second cams 112 and 114,
The positions of 2,114 can be switched.

As shown in FIG. 5B, the sun gear 100
Is rotated clockwise in the figure, the first arm 10
1 abutment piece 101a is in the meshing permission section 1 of the first cam 112.
When the first planetary gear 102 comes into contact with the spool drive gear 180, the first planetary gear 102 meshes with the spool drive gear 180 to rotate the spool 12.

As shown in FIG. 5C, the sun gear 100
Is rotated clockwise in the figure, the second arm 10
No. 3 abutment piece 103a is in the meshing permission section 1 of the second cam 114.
When the second planetary gear 104 comes into contact with the spool drive gear 14a, the second planetary gear 104 meshes with the spool drive gear 180 to rotate the spool 12.

When the first planetary gear 102 meshes with the spool drive gear 180, the drive system becomes a low-speed drive system with a high reduction ratio, and the second planetary gear 104 is driven by the spool drive gear 18.
When the gear meshes with 0, it becomes a high-speed drive system with a reduced speed ratio.

Further, the film is rewound by the feed motor 21.

That is, as shown in FIG. 6, the planetary arm 16 meshes with the sun gear 160 of the film winding drive system.
The planetary gear 162 supported by 1 is disposed so as to be in contact with or separated from the rotation transmission gear 150 to which rotation from the feed motor 21 is transmitted. The planet arm 161 is urged by a spring (not shown) in a direction in which the planet gear 162 meshes with the rotation transmission gear 150, that is, counterclockwise. One end of an interlocking arm 163 is connected to the planetary arm 161. The interlocking arm 161 is rotatably supported at the center, and has a contact piece 163 that contacts the second cam 114 at the other end.
a.

As shown in FIG. 6A, the interlocking arm 16
3 is the engagement prevention section 1 of the second cam 114.
When abutting on 14c, the interlocking arm 163 rotates the planetary arm 161 counterclockwise, so that the rotation transmitting gear 150 and the planetary gear 162 are separated and are not driven to rewind.

As shown in FIG. 6B, the interlocking arm 16
3 is in the engagement permitted section 1 of the second cam 114.
14a, the interlocking arm 163 rotates the planetary arm 161 clockwise, the rotation transmission gear 150 meshes with the planetary gear, the rotation is transmitted to the rewinding drive system, and the film is rewound. You.

By combining the first cam 112 and the second cam 114, four states can be created, and three of the states can be used to rotate the spool drive gear 180 via the first gear 112 for low-speed film feeding. Feed, second gear 1
Either high-speed film feeding in which a spool gear rotates through 14 or film rewinding in which a film rewinding drive system rotates through a planetary gear 162 can be performed.

FIG. 7 is a flowchart showing a sequence of an initial operation when the main switch S0 is turned on.

When the main switch S0 is turned on (# 1)
0 (YES), a switching condition determination subroutine described later in detail is executed (# 12), and it is determined whether or not simultaneous driving is performed (# 14).

When switching to simultaneous driving is possible, that is, when the simultaneous driving request flag is 1 (# 14)
YES), the film winding reduction ratio is set to the low speed drive system (L
Switching from o) to the high-speed drive system (Hi) (# 16), the simultaneous drive request flag is set to 0 (reset) (# 18).

When switching to simultaneous driving is impossible or unnecessary, that is, when the simultaneous driving request flag is 0 (NO in # 14), it is determined whether or not to sequentially drive (# 15).

When it is necessary to switch to sequential driving, that is, when the sequential driving request flag is 1 (# 15
YES), the film winding reduction ratio is set to the high speed drive system (H
Switching from i) to the low-speed drive system (Lo) (# 17), and sequentially sets (resets) the drive request flag to 0 (# 19).

When switching to sequential driving is unnecessary, that is, when the sequential driving request flag is 0 (# 15)
NO), # 17 and # 19 are skipped.

FIG. 8 is a flowchart of the one-frame driving photographing sequence including the reduction ratio switching judgment.

When the start switch S1 is turned on (# 20)
Then, a switching condition determination subroutine, which will be described in detail later, is executed (# 22), and the flow waits until the release switch S2 is turned on (# 24). If the release switch S2 is turned on (YES in # 24), a pre-release operation is performed (# 26), and then the shutter is run to expose (# 2).
8).

Then, it is determined whether or not the driving is performed sequentially (# 3).
0).

When switching to sequential driving is necessary, that is, when the sequential driving request flag is 1 (# 30)
YES), the film winding reduction ratio is switched, and the high-speed drive system (Hi) is switched to the low-speed drive system (Lo) (#
32) The drive request flag is sequentially set to 0 (reset) (# 34).

When switching to sequential driving is unnecessary, that is, when the sequential driving request flag is 0 (# 30)
NO), the operations of # 32 and # 34 are skipped.

Then, a return operation after the release is performed (#
36).

FIG. 9 shows # 12 of FIG. 7 and # 22 of FIG.
5 is a flowchart showing details of a switching condition determination subroutine of FIG.

First, temperature detection (# 40) and battery check are performed (# 42).

[0076] When the temperature T is lower than the predetermined value T _B (# 44
In NO), or when the power supply voltage E ₀ is less than the predetermined voltage E _B (r) (in NO at # 46), or when the power internal resistance r is larger than the predetermined value r _B (NO at # 48), # Go to 54, otherwise go to # 50.

In step # 50, the film winding drive system
It is determined whether or not the system is a low-speed drive system (Lo). If it is the low-speed drive system (Lo) (YES in # 50), the simultaneous drive request flag is set (set) to 1 (# 5).
2). If it is not the low-speed drive system (Lo) (N in # 50)
O), skip # 52.

At # 54, the film winding drive system
It is determined whether or not the current system is the high-speed drive system (Hi). If it is the high-speed drive system (Hi) (YES in # 54), the drive request flag is sequentially set (set) to 1 (# 5).
6). If not the high-speed drive system (Hi) (N in # 54)
O), skip # 56.

FIG. 10 is an explanatory diagram of a power check result determination method.

In FIG. 10A, the vertical axis is the battery open-circuit voltage E ₀ , and the horizontal axis is the power supply internal resistance r. Line S
Is the drive switching voltage when the power supply internal resistance is r: E
It is a curve which shows _B (r). Line t indicates the lowest voltage for driving the motor.

As shown in the circuit diagram of FIG. 10B, assuming that the internal resistance of the power supply is r = r ₀ + r _A , the larger the current consumption of the camera circuit, the larger the voltage drop at the resistance r ₀ + r _A. And the actual voltage applied to the camera circuit is lower. Therefore, the driving method is switched by comparing the power supply internal resistance r with a predetermined value r _B.

If the current consumed simultaneously (the motor current is particularly large, and the flash current, etc. is particularly large) is reduced and time-division is applied, the applied voltage to the camera circuit increases. When it is lower than the line S, the driving is switched from the simultaneous driving to the sequential driving.

In general, conditions for driving a load with a motor vary depending on the temperature. This is naturally due to the temperature dependence of load torque characteristics, motor output characteristics, circuit resistance (including motor winding resistance), circuit element characteristics, battery characteristics, etc. It should be noted that the “battery characteristics” change rapidly from room temperature to low temperature. As for the battery characteristics, since the power supply check circuit directly monitors the current supply capability, there is almost no need to further consider the influence of temperature. Therefore, switching of the driving method based on the determination result of the temperature condition is particularly effective as a method for coping with a change in the “load torque characteristic” condition.

The change in the “load torque characteristic” with temperature is as follows:
This is particularly remarkable in film feeding and focus lens driving. In film feeding, the fact that the hardness (spring property against bending) of the film itself changes with temperature has a great effect. At low temperatures, the film has a remarkable spring-like property, so that the resistance of the film passing through the film during feeding increases, and the load torque during feeding increases. In driving the focus lens, the fact that the viscosity of the lubricant used for the sliding portion of the lens group changes with temperature has a great effect. At a low temperature, the viscosity of the lubricant increases, which hinders the driving of the lens group, so that the load torque at the time of driving the lens increases. Therefore, the reduction ratio switching based on the determination result of the temperature condition is particularly effective in “film feeding” and “focus lens driving”.

Therefore, in FIG.
A, and the temperature T is a predetermined temperature T _BWhen it is over, high speed
The three motors are driven simultaneously by setting the drive system (Hi). region
In the case of B, drive is performed sequentially with the low-speed drive system (Lo) set.
You. In the area C, it is determined that the battery is exhausted and a warning is issued.
Display and stop motor operation.

FIG. 11 is a timing chart of simultaneous / sequential switching in the mechanical release operation before exposure.

As shown in FIG. 11A, under normal conditions, the focus motor 24, the charge motor 22,
The aperture motor 23 and the aperture motor 23 are simultaneously driven with the start start timing slightly shifted. The focus motor 24 is driven by a high-speed drive system (Hi).

When the power condition is reduced, the driving time of each motor becomes longer as shown in FIG.

When the power supply condition further decreases, simultaneous driving cannot be performed. Therefore, as shown in FIG.

The focus motor 24 and the charge motor 22 are simultaneously driven with a slight shift in the start-up start timing. When the driving of the charge motor 22 is completed, the driving of the aperture motor 23 is started. The focus motor 24 is
The drive is switched from the high-speed drive system (Hi) to the low-speed drive system (Lo).

Thus, the fluctuation (break) of the entire operation end time due to the switching of the driving method can be minimized.

The drive system of the focus motor 24 is shown in FIG.
Switching is performed by the mechanism shown in FIG.

As shown in FIG.
4 has a reduction ratio switching mechanism 38 using a friction planetary gear between the AF coupler (coupling part between the main body and the interchangeable lens) 240 and 250. Planetary gear 2
There are two meshing gears of No. 02, and the reduction ratio up to the AF couplers 240 and 250 differs depending on which gear meshes.

That is, the sun gear 2 is
00 is driven. The planetary gear 202 meshing with the sun gear 200 includes a large gear portion 212 of the first stage gear 210 and a second gear
The gear is selectively engaged with one of the small gear portions 222 of the stepped gear. The small gear portion 214 of the first stage gear 210 and the large gear portion 224 of the second stage gear 220
It meshes with an output gear 230 that drives an AF coupler 240 on the camera body side. On the interchangeable lens 80 side, the support frame 252 that supports the focus lens is driven by the rotation of the AF coupler 250.

[0095] The planetary gear 202 is a mating gear 212 or 22.
2 while rotating in both the forward and reverse directions while meshing with the projections 2, as shown in FIG.
6 has a stopper lever 260 for preventing the gears from being disengaged, and locks the planet carrier 204 except when the planetary gear is being switched.

That is, as shown in FIG. 14, one end of the stopper lever 260 is rotatably supported by the rotating shaft 266, and is biased by the spring 268 in the direction of the planet carrier lock position. A protrusion 262 is provided on the stopper lever 260 so that a driving member 270 driven by using the switching driving element 25 is engaged. The stopper lever 260 is used only when necessary (during switching).
As indicated by the dashed line, the switching drive element 25 is used to lift up against the spring force and to retreat from the projection 206 of the planet carrier 204. When the retracting force is removed, the stopper lever 260 is locked by the spring 268 to the projection 206 of the planet carrier 204 as shown by a solid line, and locked.

As the switching drive element 25, a plunger (electromagnet), bimorph (piezoelectric element), shape memory alloy, or the like can be used. Each of these elements can linearly move (pull) the load by a predetermined distance in an energized state, so that the stopper lever 260 can be retracted using this stroke.

Further, the stopper lever 260 can be driven by a cam rotated by a DC motor. In this case, the above-mentioned cam is driven by using, for example, the reverse rotation output of the charge motor (the charge / release in the forward rotation) without using the dedicated actuator as described above, and the planetary carrier is locked and disengaged. be able to.

The switching of the reduction ratio of the focus motor drive system is performed in the following procedure.

First, prior to the switching, the switching drive element 25 is driven to pull up the stopper lever 260 and retreat from the revolution path of the planetary gear 202.

When switching to the first reduction ratio (high reduction ratio), that is, the low-speed drive system (Lo), the sun gear 200 is rotated counterclockwise, and as shown by the solid line in FIG. The gear is engaged with the step gear 210. When the gear engagement is detected, the drive of the switching drive element 25 is terminated, and the stopper lever 260 is returned to the lock position.
The driving of the sun gear 200 ends. If the focus motor 24 is rotated in the normal or reverse direction in this state, the focus drive at the first reduction ratio can be performed.

Similarly, when switching to the second reduction ratio (reduced speed ratio), that is, the high-speed drive system (Hi), the sun gear 2
Then, the planetary gear 202 is meshed with the second gear 220 as shown by a chain line in FIG. 13, and then the drive of the switching drive element is terminated to lock the stopper lever 260. If the focus motor 24 is rotated forward and reverse in this state, the focus drive at the second reduction ratio can be performed.

Here, the planetary gear 202 and the first or second stage
The following method is used for detecting gear engagement with the step gears 210 and 220. The position of the planet carrier 204 is directly detected by a photoelectric element or the like. The fact that the output side has moved by a predetermined amount is detected by an output side encoder (such as an encoder in a lens). The fact that the output side has moved by a predetermined amount is detected by focus movement detection using an AF sensor via movement of the focus lens.

Here, the method of switching the reduction ratio will be further described.

In the conventional example of the reduction ratio switching, no special switching sequence is required.

For example, a mechanism with a reduction ratio A by forward rotation of the motor,
In the conventional configuration in which the motor output is connected to the mechanism having the reduction ratio B by the reverse rotation, the reduction ratio can be switched only in the direction in which the power is supplied to the motor.

In another conventional configuration in which the reduction ratio is switched when the external motor drive device is mounted on the camera body, automatic switching cannot be performed, but since the mounting operation is the switching operation itself, the switching operation is unnecessary.

Since there is no need for a special sequence for switching, there is an advantage that the operation can be performed immediately, but the motor to be used is a dedicated motor for a single load. In the former configuration,
Since the forward / reverse rotation direction of the motor is used for switching, the load cannot be rotated in both forward and reverse directions at one reduction ratio.

On the other hand, FIG.
In the configuration of FIG. 6 and FIG. 6, the control cam section is switched by the reverse rotation of the motor to switch the transmission path of the driving force, and the actual load drive is performed by using the transmission path selected by the forward rotation. In this method, since it is necessary to once reverse the motor to move the control cam for switching the reduction ratio, it is not possible to drive at another reduction ratio immediately after determining that the reduction ratio switching is necessary. On the other hand, in addition to the “transmission system having different reduction ratios”, another load (in this embodiment, film rewinding) can be assigned to the control cam, so that one motor can drive multiple loads. Can be configured. In the embodiment, the high-speed film winding (Hi), the low-speed film winding (Lo), and the film rewinding are allocated to the three sections of the control cam. No worries. Therefore, there is no need to prepare another motor for rewinding, which is reasonable.

In the configurations of FIGS. 12 to 14, which are the embodiments of the present invention, the reduction ratio is switched by another actuator. In this method, it is necessary to operate another actuator once for switching the reduction ratio. Therefore, immediately after it is determined that the switching of the reduction ratio is necessary, it is not possible to drive with another reduction ratio immediately.

On the other hand, since the reduction ratio is switched by another actuator, the load can be freely driven in both the forward and reverse directions by the forward and reverse rotation of the motor at each reduction ratio setting.

Since this configuration is used for the focus lens drive system, both the lens extension and retraction are different from each other.
This can be done via two reduction systems. As another switching actuator, it is also possible to use an output of another motor (for example, a charge motor) already provided.

In the embodiment of the present invention, a reduction ratio switching operation is required, but the switching can be performed rationally without waste by the following method.

To switch from the reduced speed ratio (Hi) to the high reduction ratio (Lo), after it is determined that the reduction ratio switching is required, a switching operation is inserted immediately before the actual driving, and the actual driving is continued. Just move on. At this time, since it has been detected that the driving condition has changed from the good condition to the bad condition, a prompt switching operation is required to guarantee stable driving thereafter.

Conversely, from the high reduction ratio (Lo) to the reduced speed ratio (H
The switching to i) may be performed by performing a switching operation following the initializing operation when the main switch S0 (power switch) is turned on after it is determined that the reduction ratio switching is necessary, and shifting to a standby state. At this time, since it is detected that the driving condition has changed from the bad condition to the good condition, it is not necessary to immediately perform the switching operation in terms of driving assurance. Therefore, the same driving method is continuously performed while a continuous shooting operation is expected to be performed, and the ON / OFF operation of the main switch S0 is used as a break.

As described above, hysteresis is given to the execution determination of the switching of the driving method, so that even if the result of the determination of the driving condition fluctuates due to a slight change of the condition (power supply, temperature), a plurality of reduction ratios or sequences to be used are used. There is no loss of operability by going back and forth between settings.

As described above, in a camera in which a plurality of motors share the driving of the mechanism in the camera, whether the motors required for the same sequence section are driven simultaneously based on the detection result of the operating power supply condition and the operating environment temperature. , A part of which is sequentially driven. Further, at least one motor drive mechanism can be switched to a plurality of reduction ratio settings,
This reduction ratio is also switched in conjunction with the simultaneous / sequential switching.

When the driving conditions are in a standard state (good conditions), a plurality of motor driving mechanisms can be driven at the same time so that the necessary mechanical driving can be performed in a short time. By sequentially driving a part of the driving mechanism, the driving time is prolonged, but the operation can be performed under conditions worse than the limit conditions at the time of simultaneous driving.

Further, at least one of the three motor drive mechanisms can be changed, and the reduction ratio is changed in conjunction with the switching between the simultaneous drive and the sequential drive. It is possible to set so that a break point where the operation time greatly changes is unlikely to occur.

Further, since the result of checking the battery consumption state and the result of detecting the internal temperature of the camera are used in combination with the judgment of favorable / bad conditions, the energy supply capacity (battery consumption state) and the required energy before the actual driving are performed. (Necessary current determined by the magnitude of the load that changes depending on the temperature) can be accurately determined.

According to this method, it is possible to optimize the driving time under the good condition and the bad condition so that the driving time is shortened. Can be avoided.

Therefore, in a camera in which a plurality of motors share the drive of the mechanism inside the camera, by changing the driving method in accordance with the power supply capability, it is possible to minimize the variation (breakpoint) of the entire operation end time as much as possible. ,
It is possible to achieve both "reduction in operating time" and "increase in the number of films that can be photographed without replacing batteries".

The present invention is not limited to the above embodiment, but can be implemented in various other modes.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an internal structure of a camera according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control system of FIG.

FIG. 3 is a timing chart of one-frame shooting.

FIG. 4 is a timing chart of driving a motor after exposure.

FIG. 5 is a configuration diagram of a reduction ratio switching mechanism.

FIG. 6 is a configuration diagram of a reduction ratio switching mechanism.

FIG. 7 is a flowchart of an initial operation.

FIG. 8 is a flowchart of one-frame shooting.

FIG. 9 is a flowchart of a subroutine for switching condition determination.

FIG. 10 is an explanatory diagram of a power check.

FIG. 11 is a timing chart of motor driving before exposure.

FIG. 12 is a configuration diagram of a reduction ratio switching mechanism of a focus drive system.

FIG. 13 is an enlarged view of a main part of FIG.

FIG. 14 is a side view of a main part of FIG.

[Explanation of symbols]

Reference Signs List 21 feed motor (drive source) 22 charge motor (drive source) 23 aperture motor (drive source) 24 focus motor (drive source) 36 reduction ratio / driven unit switching mechanism (drive system switching unit) 38 reduction ratio switching mechanism ( Drive system switching unit) 50 control circuit (drive condition determination unit, control unit) 54 power supply check circuit (drive condition detection unit) 55 temperature detection circuit (drive condition detection unit)

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F16H 3/34 F16H 3/34 37/06 37/06 F (72) Inventor Satoshi Umemiya Azuchi-cho, Chuo-ku, Osaka-shi, Osaka 2-3-13, Osaka International Building Minolta Co., Ltd. (72) Inventor Hidehiko Fujii 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Co., Ltd. (72) Inventor Akihiro Oki Osaka 2-13-13 Azuchicho, Chuo-ku, Osaka-shi Osaka International Building Minolta Co., Ltd. F-term (reference) 2H020 MA01 MA02 MC22 MC27 MC31 MC32 MC33 MC34 MC53 MC54 MC55 MC59 ME02 ME03 ME04 ME13 ME14 3J028 FB14 FC49 GA33

Claims (6)

[Claims] 1. At least three first, second, and third drive sources that receive power supply from one power source respectively drive at least three different first, second, and third driven members. In the camera, first and second ones of which transmit a driving force so as to be switchable from the first driving source to the first driven member.
A driving system for transmitting a driving force from the first driving source to the first driven member, wherein a power supply amount per unit time from the power supply to the first driving source is relatively small. A first drive system, a second drive system having a relatively small amount of power supply per unit time from the power supply to the first drive source, a first drive system, and a second drive system. The driving system is switched so that a driving force is transmitted from the first driving source to the first driven member via one of the first driving system and the second driving system. A drive system switching unit; a drive condition detection unit that detects drive conditions of the drive sources; and a determination whether the power supply has a margin for power supply based on the drive conditions detected by the drive condition detection unit. A driving condition judging unit for judging, based on the judgment of the driving condition judging unit, When it is determined that the power supply has enough power supply, the drive system switching is performed so that the first driven source transmits a driving force to the first driven member via the first drive system. And performs first control for controlling the respective driving sources so that the respective driving sources are simultaneously driven. When it is determined that the power supply has no margin for power supply, the second control is performed. The first driven source controls the drive system switching unit such that the first driven source transmits a driving force to the first driven member via a driving system, and the first driving source is driven. A control unit for performing a second control for controlling each of the driving sources so that the second and third driving sources are sequentially driven. 2. The camera according to claim 1, wherein the drive condition detection unit detects, as the drive condition, an ability of the power supply to supply power to each of the drive sources. 3. The driving condition detecting section detects a temperature inside a camera as the driving condition.
The camera according to claim 1. 4. The camera according to claim 1, wherein the first drive system has a relatively small speed reduction ratio, and the second drive system has a relatively large speed reduction ratio. 5. The camera according to claim 1, wherein the drive condition detection unit, the drive condition determination unit, and the control unit operate when an operation of turning on a power switch of the camera is performed. 6. The apparatus according to claim 1, wherein the drive condition determination section continues the determination until the power switch of the camera is turned off after determining that the power supply has no margin. camera.