JP2950686B2 - camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a built-in motorized film rewinding mechanism, and more particularly to a camera capable of reducing noise when rewinding a film.

[0002]

2. Description of the Related Art Conventionally, a camera incorporating a motorized film rewinding mechanism is provided with film movement detecting means for generating a signal in accordance with the movement of the film, and this signal changes during film rewinding. During this time, the rewind motor continues to be energized, and since this signal no longer changes, it is determined that the film leader has come out of the take-up spool, and then the film leader has come out of the cartridge. To terminate the rewinding, or to terminate the rewinding in a state where the film leader is wound in the patrone, depending on whether the motor is immediately de-energized, or de-energized after energizing for a predetermined time, Is controlled.

By the way, in recent camera designs, in order to reduce the motor operation sound during film rewinding and reduce the noise, the power supply voltage to the motor during film rewinding is reduced to reduce the motor rotation speed. Noise reduction measures have been proposed.

According to this noise reduction measure, noise at the time of film rewinding can be reduced, but there is a disadvantage that the rewinding time becomes longer because the motor speed is reduced. For this reason, the rewind speed is set so as to be an acceptable rewind time (for example, 30 seconds) for the use of the camera. Normally, the rewind speed is set to an allowable limit for 36 sheets of film. Time will be set.

On the other hand, in addition to the above-mentioned noise reduction technique of lowering the rotation speed of the motor than before, a belt-type power transmission mechanism is adopted as the power transmission mechanism of the film rewinding mechanism to generate noise during film rewinding. Prevention is also being done.

With the adoption of such noise reduction technology, recent cameras have been trying to reduce the film rewind noise so that the user does not notice that the film is being rewound.

[0007]

However, even in a camera designed by using the above-mentioned noise reduction technology, there are the following problems to be further improved.

(I) In a camera in which the number of revolutions of the film rewind motor is made lower than that of the conventional camera when rewinding the film, and in which the film leader is wound into the cartridge at the end of rewinding, Even after the film comes out of the take-up spool during return, the motor continues to be normally energized for 2 to 3 seconds. At this time, the film has come off the spool, so the rotational load on the motor is the amount of rotation of the fpool. If the film becomes lighter and then the film is further wound and the leader enters the cartridge, the rotational load on the motor is further reduced. For this reason, in such a system, the motor speed increases during the period from when the film comes out of the spool to when it is wound on the patrone and the motor stops, as compared with during rewinding, as the motor load becomes lighter. As a result, there arises a problem that the motor noise becomes large only during the operation of winding the film leader.

(Ii) In a camera in which the rotation speed of the film rewinding motor is made lower than that of the conventional camera at the time of rewinding the film, power is supplied to the motor from the start to the end of the rewinding. Since the voltage is almost constant, the following problems occur.

In the initial stage of film rewinding, since the film is hardly wound around the winding shaft in the patrone, the substantial diameter of the winding shaft is small. Since it is wound around the shaft, the substantial diameter of the winding shaft becomes large. However, the force required for film rewinding is almost constant in the tangential direction of the film, so the rotational load of the patrone winding shaft is light at the initial stage of film rewinding,
It gets heavier at the end.

For this reason, if the power supply voltage to the motor during film rewinding is constant, the load on the motor fluctuates, and the motor speed at the beginning of rewinding is considerably higher than at the end, and as a result, However, a problem arises when the motor noise becomes large in the initial stage compared to the end of the rewinding. Therefore, in the method of reducing the power supply voltage to the motor to reduce the noise, it is necessary to set the drive voltage to a large value corresponding to a large load at the end of rewinding. At the time of load, there is a problem that the number of revolutions of the motor does not drop sufficiently and the effect of noise reduction cannot be obtained sufficiently.

Therefore, in order to avoid such a problem,
A method has been considered in which the motor rotation speed is controlled to be constant by detecting the motor rotation speed and performing feedback control.However, to implement this method, a new motor rotation speed detection device must be placed in the camera. Inevitably, there were problems in terms of space and cost.

(Iii) In a camera in which the number of rotations of the motor at the time of rewinding the film is made lower than that of the conventional camera, the camera is not a 36-film camera but a film.
In the case of using 24-film film or 12-film film, the rewinding time is naturally considerably shorter than in the case of using 36-film film. There will be a margin, but there is no problem if the noise is already sufficiently reduced at the motor speed set for the 36-shot film, but in reality, the rewind time for 36-shot film In many cases, the motor rotation speed set so as to be within the allowable time is insufficient for noise reduction. Therefore, it is originally desirable that the motor rotation speed can be set lower.

Therefore, in the state where the 24-film film or the 12-film film is used as described above, the setting of the motor rotation speed is optimal or the balance between the noise reduction effect and the rewinding time is optimal. There is a problem that it cannot be the best setting in the state of use.

(Iv) It is preferable that the rewinding operation sound of the camera be reduced to a level that is invisible to the user, but on the other hand, whether the rewinding operation is in progress for the user or the camera There is a problem that it is difficult to determine whether the vehicle is in the stopped state.

In particular, in a camera that performs automatic rewinding,
If the camera starts rewinding automatically after the last frame of the film has been shot, the user does not immediately know that the rewinding operation is in progress, and despite the fact that the rewinding operation is in progress, The problem of trying to shoot arises.

Conventionally, as a method of indicating the operation while the camera is performing the rewinding, a method of displaying that the rewinding operation is being performed on an external display device using a liquid crystal, or a method interlocked with the rewinding is used. In some cases, the display on the film counter was calculated backwards, but these only indicate that the rewinding operation was performed normally, and whether or not the camera started the rewinding operation was performed. It is actually determined by the rewind operation sound.

When the rewinding operation is completed, the situation is the same as described above. In the conventional camera, it was found that the rewinding was completed by stopping the operation sound. In such a camera, there is a problem that the end of rewind cannot be known unless the external display is continuously viewed during the rewind operation.

An object of the present invention is to provide a camera which has solved the above-mentioned problems of the conventional camera.

[0020]

(I) In order to solve the above-mentioned problem (i), the first or second camera of the present invention detects the movement of the film during the film rewinding and detects the movement of the film. After detecting that there is no change in the film movement signal at the end of the return, the motor is energized for a predetermined time in order to wind the film leader portion into the cartridge, and then the motor energization is stopped. Supply voltage to
Control means for controlling is provided, during motor energization for involving film leader portion described above into the cartridge, a supply voltage to said motor <br/> motor film movement signal changes
Control to lower the power supply voltage at
When the film rotation signal is changing
Supply the motor so that it does not exceed the rotation speed.
Control the voltage. This prevents an increase in the number of motor revolutions at the time of the leader section entanglement operation, and prevents the generation of noise.
It was so.

(Ii) In order to solve the problem described in the above (ii), the third camera of the present invention employs a film winding
An electric film rewind mechanism that performs rewinding with a motor,
The film movement amount detecting means for detecting a film rewinding amount provided, the rotation speed of the motor even film rewinding proceeds
Controls the power supply voltage to the motor so that the degree is almost constant
Control means for performing the operation .

(Iii) In order to solve the problem described in the above (iii), the fourth camera of the present invention employs a film winding
An electric film rewind mechanism that performs rewinding with a motor ,
A film number reading means for reading the number of films; control for changing the rotation speed of the motor in accordance with the information on the number of films read by the film number reading means;
Means were provided .

[0023]

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

<Embodiment 1> FIG. 1 is a block diagram showing an electric control system of a camera embodying the present invention. Reference numeral 1 denotes a microcomputer for controlling the movement of each part of the camera. Reference numeral 2 denotes a lens control circuit that drives and controls a focus adjustment motor and an aperture blade control motor of a photographic lens (not shown). The lens control circuit 2 performs serial communication via DBUS while receiving the LCOM signal from the microcomputer 1. The motor drive information is received by serial communication, and the drive of the motor is controlled based on the information. At the same time, various information (focal length etc.) of the lens is transmitted to the microcomputer 1 by serial communication.

Reference numeral 3 denotes a liquid crystal display circuit, which is used to capture information of each camera, such as shutter speed, aperture value, ISO sensitivity,
This is a circuit for driving a liquid crystal display (not shown) for notifying a photographer of the number of films, an exposure correction value, a photometric mode, and the like. The liquid crystal display circuit 3 is a microcomputer 1
While receiving the DPCOM signal from the PC, serial communication is performed via DBUS. The display data is received by serial communication, and the liquid crystal display is driven according to the data.

Reference numeral 4 denotes a switch sense circuit, which is a circuit for reading the state of a switch for setting each photographing condition or a switch indicating the state of the camera by the photographer and sending it to the microcomputer 1, and receiving a SWCOM signal. Meanwhile, switch data is sent to the microcomputer 1 by serial communication via DBUS.

Reference numeral 5 denotes a strobe light emission dimming control circuit, which controls a strobe light emission and a light emission stop function by TTL light control. The flash emission dimming control circuit 5 is an STCO
While receiving the M signal, the microcomputer 1 performs serial communication with the microcomputer 1 via DBUS, receives data related to strobe control, and performs various controls.

Reference numeral 6 denotes a focus detection circuit, which is a line sensor for performing AF by an existing phase difference detection method and a circuit unit for storing and reading out the information.

Reference numeral 7 denotes a photometry circuit which performs photometry of a subject and sends a photometric output to the microcomputer under the control of the microcomputer 1. The microcomputer 1 performs A / D conversion of the sent photometric output and uses it for setting exposure conditions (aperture, shutter speed).

Reference numeral 8 denotes a shutter control circuit which controls the running of a shutter first curtain and a rear curtain (not shown) according to a control signal of the microcomputer 1.

A feeding circuit 9 feeds (winds up and rewinds) the film in accordance with a control signal from the microcomputer 1 based on the film signal.

SW1 is a switch interlocked with a button (not shown) for starting the operation of the camera.
When the microcomputer 1 recognizes that N has been performed, photometry, distance measurement, and display are started.

The switch SW2 is linked with the release button of the camera, and starts the exposure operation when the microcomputer 1 recognizes that the switch SW2 is turned on.

The X contact is turned on at the timing when the front curtain of the shutter runs completely, and serves to notify the flash light emission control circuit 5 of the flash light emission timing.

The film signal generated by the switch 11 changes when the film is moving, and does not change when the film is stopped.

FIG. 2 is a flowchart showing the present embodiment. This embodiment will be described below with reference to FIG.

(200): Start position of this flow. (201): It is determined here whether rewinding is to be started. The start of rewinding corresponds to a case where the number of images that can be photographed is completed or a case where the forced rewind button is pressed. If it is determined that rewinding starts, the process proceeds to (202).

(202): The rewind voltage applied to the rewind motor is set here. In this embodiment, the voltage of the feeding motor is changed when the signal 11 from the film can be read by the rewinding operation and when the signal 11 from the film cannot be read because the film is no longer at the signal detection position. The rewind voltage set here is a voltage at which a signal from the film can be read.

(203): The rotation of the feed motor (not shown) is started by the feed motor control circuit of FIG. 1, and (204)
Proceed to.

(204): It is determined whether or not the film signal 11 in FIG. 1 has changed. Here, the change in the film signal means that the perforation of the film passes over a film detection position (not shown) or that the signal obtained by converting the perforation into another signal changes with the movement of the film. Thus the fact that there is a change in the film signal 11, the film is that it has not returned winding still, immediately after the change of the film signal 11 has disappeared, is in a state in which the leader portion of the film is still out slightly from the cartridge it is conceivable that.
At (204), it is determined whether or not the change of the film signal has been eliminated. If the change of the film signal has been eliminated, the process proceeds to (205).

(205): Since the change of the signal of the film is stopped in (204), the leader of the film has not yet been caught in the cartridge. Here, a voltage for winding the remaining leader portion into the cartridge is set, and the process proceeds to (206).

Here, at least the film signal 11 is read.
After removal, the load on the film is light, and it is for feeding
The load on the motor is also light. For this reason , the voltage set here does not suddenly increase the rotation speed of the feeding motor.
To odd, a voltage lower than the voltage set for rewind (202). This allows
The quietness can be enhanced throughout the entire unwinding process.
You .

(206): Since the voltage for winding the film leader section is set in (205), the film reader section is completely wound into the cartridge by the feed motor control circuit of FIG. 1 based on this voltage. The feeding motor (not shown) is rotated for a sufficient time.

(207): A fixed time of (206),
After the motor for feeding is rotated, the motor is stopped at (207), and the completion of rewinding is displayed by the liquid crystal display and the circuit 3 of FIG. (208): End of the flowchart.

According to the embodiment described above, the voltage of the feeding motor is changed (reduced) at the time of rewinding the photographic frame portion of the film and at the time of winding the leader portion of the film, so that the winding can be performed quietly. Can be returned.

Embodiment 2 Next, a second embodiment of the present invention will be described with reference to FIGS.

Although the camera of the present embodiment is constituted by almost the same electronic circuit as the camera of the first embodiment, the contents of the microcomputer and the configuration and functions of the control system are different from those of the first embodiment.
Is different from Therefore, the configuration of the electronic circuit system of the present embodiment is applied to FIG. 1, and the description will be omitted unless necessary.

FIG. 3 is a flowchart showing the present embodiment.
This embodiment will be described below with reference to FIG.

(200): Start position of this flow. (201): It is determined here whether rewinding is to be started. The start of rewinding corresponds to a case where the number of images that can be photographed is completed or a case where the forced rewind button is pressed. If it is determined that rewinding starts, the process proceeds to (202).

(202): The rewind voltage applied to the rewind motor is set here. This embodiment is characterized in that the rotation speed of the motor is kept constant by changing the voltage value applied to the rewinding motor according to the number of rewinding frames. In other words, when the same voltage is always applied, when the rewinding is started, the load on the motor is light because the diameter of the film wound on the patrone shaft is small, so the rotation speed of the motor is fast, but the rewinding is completed. In the vicinity of the time, the load is large because the diameter of the film wound around the patrone shaft is large, so that the rotation speed of the motor is slow.
The present embodiment is characterized in that the voltage applied to the feed motor is changed according to the number of frames of the film to be rewound to control the rotation speed of the feed motor to be constant. In (202), the voltage at a light load at the start of rewinding is set as the voltage to be applied to the feed motor.

(203): It is determined whether or not the rewinding of the film caused by the switch 11 in FIG. 1 has been completed. If it is determined that the processing is to be ended, the process proceeds to (206),
When it is determined that rewinding is being performed, the process proceeds to (204).

(204): It is determined whether or not the film has been rewound by one frame based on the film signal generated by the switch 11 in FIG. If it is determined that the rewinding of one frame has not been completed since the last rewinding of one frame, the process proceeds to (203). If it is determined that the rewinding of one frame has been completed, the voltage is determined. Proceed to setting (205).

(205): The feed motor voltage is set so that the rotation speed of the feed motor is constant according to the rewind frame state. This voltage is measured in advance and stored in the microcomputer as table data, and in addition to the method of setting by referring to the table, the moving speed of the film is measured, and the feeding motor is accordingly determined. May be calculated and set.

Here, by setting the voltage corresponding to the number of film frames, the rewinding is continued by the feed motor control circuit 9 in FIG. 1, and the process proceeds to (203).

(206): If it is determined in (203) that the rewinding has been completed, the feeding motor (not shown) is stopped, and the completion of the rewinding is displayed on the liquid crystal display circuit 3 in FIG. Display by (207): End of the flowchart.

According to this embodiment, the rotation speed of the feeding motor is kept constant by setting the voltage applied to the feeding motor in accordance with the number of rewinding frames of the film. It is possible to suppress the change of the motor rotation sound depending on the number.

<Embodiment 3> Next, a third embodiment of the present invention will be described with reference to FIGS. FIG.
In FIG. 7, the description of the components denoted by the same reference numerals as in FIG. 1 and already described in FIG. 1 will be omitted.

In FIG. 4, DXSW is a DX code reading switch for reading a DX code on a film cartridge.

FIG. 5 is a flowchart showing the present embodiment.
This embodiment will be described below with reference to FIG.

(200): Start of this flowchart. (201): It is determined whether or not shooting of all frames of the film loaded in the camera is completed and a rewind operation is started. Here, if the number of shootable images still remains, the process proceeds to (202), and the photographable state is maintained. On the other hand, if the number of recordable images does not remain, the process proceeds to (203).

(202): When photographing is performed, the exposure is performed by pressing the release switch SW2, and after the film is wound up, the flow proceeds to (201).

(203): Here, it is determined whether or not the number read by the DX code read by the switch sense circuit 4 in FIG. 4 is 36. Where 3
If it is determined that six shots are taken, the rewind voltage level A for 36 shots is set in (204), and the rewind operation is performed by the feed motor control circuit in FIG. Do. If it is determined that it is not 36 shots, the process proceeds to (205), and it is determined whether 12 shots or 24 shots are taken.

(204): The voltage level A for taking 36 shots is set as the rewinding motor voltage.

(205): Here, it is determined from the DX code read by the switch sense circuit 4 in FIG. 4 whether the number of shots read is 24 or 12 shots. Here, when it is determined that 24 shots are taken, the process proceeds to (206), where a rewind voltage level B for 24 shots is set, and in (208), the voltage is used by the feed motor control circuit of FIG. A rewind operation is performed. If it is determined that 12 shots are taken (207)
Then, the rewind voltage level C for taking 12 frames is set. At (208), the rewind operation is performed by the feed motor control circuit of FIG. 4 using the voltage.

(206): The voltage level B for taking 24 shots is set as the rewinding motor voltage. (207): The voltage level C for taking 12 pictures is set as the motor voltage for rewinding. (208): Rewinding is performed using the feed motor control circuit shown in FIG. 4 with the rewind voltage set as described above.

(In the present embodiment, only the voltage levels for taking 36, 24, and 12 shots are prepared, but voltage levels may be prepared for other shots.) A, B, and C, as shown in the above flowchart, make the winding time constant regardless of the number of shots by selecting the motor voltage for rewinding according to the number of shots read by the DX code. Such a voltage value.

<Related Art Example> A related art example of the present invention will be described with reference to FIG. 6 and FIG. Note that, in the electrical configuration of the camera shown in FIG.
The description of the components already described in FIGS. 1 and 4 will be omitted.

A feature of the camera of this embodiment shown in FIG. 6 is that a sounding body 14 is provided and a control means for operating the sounding body 14 is provided. Also,
SW3 is a selection button for performing rewinding after photographing by the camera at high speed or at low speed (low sound).

SW4 is a selection button for selecting whether to sound the buzzer (sounding body) 14 at the time of rewinding at a low speed (low sound).

FIG. 7 is a flowchart showing the present embodiment.
This embodiment will be described below with reference to FIG.

(200): When a predetermined number of images have been photographed and the film has been rewound, the feed motor control circuit 9 in FIG. Perform rewind. Here, when the low-speed (silent) rewind is selected by SW3 in FIG. 6, the feed motor control circuit 9 performs control such that the motor voltage is reduced to enable low-speed and quiet rewind. When the high-speed rewinding is selected by SW3, control is performed so that the motor voltage is increased to enable high-speed rewinding.

(201): It is determined whether low-speed (silent) rewind is selected by SW3. If the low-speed (silent) rewind is not selected, the process proceeds to (204). If the low-speed (silent) rewind is selected, the process proceeds to (202).

(202): It is determined whether or not the buzzer sound is required by SW4 in FIG. If it is determined that the buzzer sound is necessary, the process proceeds to (203), and if it is determined that the buzzer sound is not necessary, the process proceeds to (204).

(203): Switch sense circuit 4 in FIG.
Serial communication for generating a buzzer sound is performed, and the sounding body 14 sounds.

(204): Here, in order to sound the buzzer sound in a certain time period, it waits for a certain period of time to judge whether to sound the buzzer sound. If you increase this time, the sounding interval of the sounding body will increase, and if you shorten this time,
The sounding body sounds at short intervals.

(205): It is determined whether or not the rewinding is completed based on the film signal of the switch 12 in FIG. When the rewinding is completed, the process proceeds to (206), the feeding motor is stopped, and the rewinding is completed. (The rewind complete display is displayed by the liquid crystal display circuit of FIG. 6). If it is determined that rewinding is being performed, the process returns to (201).

As described above, according to this embodiment, S in FIG.
If the buzzer sound is set to be necessary for rewinding at low speed (silent) by W3 and SW4, the buzzer sounds during rewinding at a certain period, so that the camera user must rewind the film. Can be reliably recognized.

[0079]

As described above, according to the camera of the present invention, the following effects can be obtained.

(I) A sharp increase in the number of revolutions of the film rewind motor after the film comes off the take-up spool.
Since so as to control the supply voltage to the motor so as to prevent, it is possible to quiet rewinding operation throughout rewinding process.

(Ii) Even if film rewinding progresses from the beginning of rewinding to the end of rewinding, the rotation speed of the motor is reduced.
By controlling the supply voltage to the motor so that a substantially constant, thereby preventing the generation of noise during unwinding and prevent fluctuations in rotational speed of the motor.

(Iii) Film number information (film structure)
Since it is configured to automatically set the rotation speed of the film rewinding motor according to Narukoma number), it small number of configuration frames
In the case of using a thin film (for example, a 12-frame film) , there is no possibility of generating a loud noise when rewinding the film.

[0083]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an electric configuration of a camera according to a first embodiment and a second embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation and functions at the time of film rewinding in the camera of the first embodiment.

FIG. 3 is a flowchart showing a control operation and functions of the camera according to the second embodiment of the present invention when rewinding the film.

FIG. 4 is a schematic diagram of an electrical configuration of a camera according to a third embodiment of the present invention.

FIG. 5 is a flowchart showing a control operation and functions of the camera of the third embodiment when rewinding a film.

FIG. 6 is a schematic diagram showing an electrical configuration of a camera according to a related art example of the present invention.

FIG. 7 is a flowchart showing a control operation and functions of the camera of the related art at the time of film rewinding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... microcomputer 2 ... lens control circuit 3 ... liquid crystal display circuit 4 ... switch sense circuit 5 ... strobe light emission dimming control circuit 6 ... focus detection circuit 7 ... photometry circuit 8 ... shutter control circuit 9 ... feeding motor control circuit 10 ... Electronic dial 11 ... film signal generation switch 14 ... sounding body

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G03B 17/00

Claims (4)

(57) [Claims] 1. A camera having an electric film rewinding mechanism for rewinding a film by a motor, and a film movement signal generating means for generating a film movement signal, wherein the film movement signal is generated during a film rewinding process. Is stopped changing for a predetermined time after
Film leader until power is turned off
A camera comprising: control means for controlling a power supply voltage to the motor at the time of the operation of winding the unit into the patrone so as to be lower than a power supply voltage at the time when the film movement signal is changing. 2. An electric film rewinding mechanism for rewinding a film by a motor, and a film rewinding signal generating circuit.
Wherein the film movement signal is changed during the film rewinding process.
After rewinding, continue rewinding for
Film leader until power is turned off
Speed of the motor during the operation of winding the part into the patrone
Degree is higher than the rotation speed when the film movement signal is changing
A camera having control means for controlling a power supply voltage to the motor so as not to become too high . 3. An electric film rewind mechanism for rewinding a film by a motor, and detecting a film rewind amount.
A film moving amount detecting means, a camera that has been closed and also the film rewinding progresses the rotational speed of the motor substantially to
Camera characterized that you have to have a control means for controlling the supply voltage for the motor to be constant. 4. An electric film rewind mechanism for rewinding a film by a motor, and a filter for reading the number of films.
The number of films read by the film number reading means in a camera having
Control means for changing the rotation speed of the motor according to the information
Camera, characterized in that it has a.