JPH0354539A - Electronic still camera - Google Patents

Abstract

PURPOSE:To minimize constitution by arranging an optical LPF, a focal plane shutter and an image pickup element in a photographing path in prescribed manner. CONSTITUTION:The optical LPF 18 is provided in front of a shutter 15 and a space between a quick return mirror 5 for a finder and the focal plane shutter 35, and thereby the reduction in shutter efficiency, which is caused by shutter thickness, can be prevented. The image pickup elements such as the magnetic disk of a cassette 20 are arranged close to the back of the shutter 35, and a still picture is electrically recorded on the disk 20a via a magnetic head. Through this arrangement, the dead space is utilized to closely dispose three photographing components in the optical path, whereby the constitution of the electronic still camera is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic still camera that records still images on an electronic recording medium such as a disk-shaped magnetic recording medium such as a magnetic notebook or a magnetic disk.

In conventional inventions related to this type of device, sufficient consideration has not been made to the optical low-pass filter, the four-plane plane, and the arrangement of the image pickup device.

An object of the present invention is to provide a compact electronic still camera that takes the above points into consideration.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the embodiment, a disk-shaped magnetic recording medium is used as an electronic storage medium.

FIG. 1(a) and FIG. 1(1+) are a front perspective view and a top view showing the external appearance of an electronic camera (hereinafter abbreviated as a camera) according to the present invention. In the figure, Ca indicates the camera body.

Reference numeral 1 denotes a normal interchangeable lens, which is provided with adjustment parts necessary for normal photography, such as a distance adjustment ring and an aperture adjustment ring.

3 is a lens mount formed to be engageable with the rear end of the interchangeable lens l. An automatic aperture interlocking lever 4 provided within the lens mount opening engages with an aperture lever 2 provided on the side of the interchangeable lens to constitute a known automatic aperture function. Reference numeral 5 denotes a quick return mirror (hereinafter referred to as mirror) for extracting light from the finder. The numeral 7 located coaxially with the release button 6 on the top of the camera is a mode switching ring that allows you to switch between single-frame shooting (S mode) and continuous frame shooting (C mode), lock the release button, and take long-time shooting. It is designed to switch to a position (OFF) for when there is no one (described later). Reference numeral 8 denotes a display for indicating the number of photographed frames, which is constituted by a liquid crystal digital display, for example, and indicates the track position of the head for recording on the magnetic disk as a recording medium. Reference numeral 9 denotes a recording/non-recording switch for recording on the magnetic disk as usual during camera operation and for moving the head to the next frame without recording. In other words, by setting the selector switch 9 to the non-recording position (NR) and operating the release button, the recording head can be set to the desired number of frames, since only recording to the disc is not performed during the normal shooting operation. It is possible to move the position of. IO is a shutter speed setting dial, and 1l is a flashlight attachment unit, which is provided with a contact 11a for transmitting and receiving signals. 12 is an eyepiece eyepiece.

Figures 2(a) and 2(bl are cross-sectional views of the camera according to the present invention, and are a horizontal cross section and a vertical longitudinal section, respectively; Cross-sectional view, Figure 2 (bl
is a cross-sectional view taken along the line ■-■ in FIG. 1(b). Figure 2 (al
2 shows a state in which a magnetic recording disk cassette 20 (hereinafter simply referred to as a cassette) is inserted or removed, and FIG. Figure 2 (a), (
In b), 23 is a cassette holder into which the cassette 20 is inserted, and is rotatably coupled to the link member 22 by a pin 22a. The link member 22 is rotatably attached to the camera body around a shaft 22b. Therefore, the center holder 23 is connected to the pin 21 provided on the back cover 2l.
c, in conjunction with the opening/closing operation of the camera back 21,
The camera body is taken in and out of the cassette storage section 24. Also, inside the cassette holder 23 there is a cassette 2
0 positioning spring 23a is provided. Figure 2 (a
) When inserting the cassette into the cassette holder 23 and closing the back cover 21, the link member 22 moves the cassette 20 and cassette holder 23 parallel to the rotation axis of the disk drive shaft 25. The center hole of the rotary hub 20b at the center of the magnetic recording disk 20a in the cassette fits into the center shaft 25a of the disk drive shaft 25. At this time, the drive pin 25b provided on the disk drive shaft 25 is pushed in the axial direction by the rotating hub against a spring (not shown).

After that, the rotation of the disk rotation motor Ml is caused by the rotation of the belt 26.
When the pin 25b moves and comes to the position of the small hole of the rotating hub 20b, the bottle fits into the small hole due to the force of the spring (not shown), and the rotational force of the motor Ml is transferred to the disk. 20a. Also,
During this cassette insertion operation, the holder presser spring 21a provided on the back cover 21 positions the cassette holder 23, and the hub presser 2lb also positions the disk's rotating hub 23.
0b, the rotary hub is engaged with the drive shaft 25, and the rotary hub is pressed lightly against the drive shaft 25, resulting in the mounted state shown in FIG. 2(b). A cover plate 27 prevents dust from entering the cassette storage section 24, and is rotatably attached to the camera body, and is rotated to the retracted position when the cassette holder 23 is moved to insert the cassette. When the cassette is inserted as described above, the magnetic head 30 moves to the cassette holder 23,
The heads come into contact with the magnetic disk 20a through the head insertion holes drilled in each disk cassette 20, and become ready for magnetic recording.

Conversely, when taking out the cassette, the cassette holder is placed in the state shown in FIG. .Figure 2 (al. 28
is the back cover opening/closing detection pin, which detects the opening and closing of the electrical contact Sl in conjunction with the opening/closing of the back cover.For example, when the back cover is open, the camera does not operate even if the release button is pressed. It is for carrying out. Reference numeral 29 denotes a battery storage lid for storing the power source 34. 3l is a circuit board containing a solid-state image sensor, and is attached to the support board I9 of the camera body with adjustment screws 32 so that its position can be adjusted.

A color separation filter (not shown) and an infrared cut filter for compensating the spectral sensitivity of the element are arranged on the front surface of the image element provided on the circuit board 3l. 3
Reference numeral 5 denotes a well-known mechanically driven electronically controlled four-force rubrene shutter, and an optical low-pass filter 18 is disposed in front of it. The reason why the optical low-pass filter 18 is disposed in front of the shutter is to prevent a decrease in printing efficiency due to the thickness of the filter. 33
33b are electronic circuit printed circuit boards for image signal processing. In FIG. 2 (81), D1 and D2 arranged on the left and right sides of the mirror box respectively indicate the operation of the quick return mirror 5 and the drive mechanism (D) of the automatic aperture lever 4.
I) and each block (details will be described later) of the drive mechanism section (D2) of the shatter charge mechanism and the magnetic head moving mechanism.

When observing the finder image before and after the shooting operation, see Figure 2 (b).
As shown in FIG. 2(b), the light beam reflected by the quinocrine return mirror 5 (a semi-transparent mirror or a half prism is also possible) forms an image on a screen 17 as shown in FIG. 2(b). The light is guided to the eyepiece l3 via the condenser lens I6 and the Venta prism 15. A finder optical path glass block l4 is placed between the pentaprism and the eyepiece to prevent the finder's eye point from becoming too short. Reference numeral 100 is a known light receiving element for measuring the brightness of an object, and is made of, for example, a silicon photodiode. A motor M2 disposed at the bottom of the mirror box is a motor that serves as a power source for a drive mechanism unit D2 that drives a mirror and an automatic aperture, and a drive mechanism unit D2 that drives a shutter charge and movement of a magnetic head. D3 is a magnetic disk rotation mechanism section. FIG. 3 is a perspective view of the main mechanical parts of the camera according to the present invention, including a mirror mechanism, an automatic aperture mechanism, a shutter charge mechanism, and a driving part for a magnetic head moving mechanism.

FIG. 3 shows a state after the completion of the photographing operation and before a new photographing operation is started. Mirror holding plate 36 that holds the mirror 5
is rotatably supported by rotating shafts 37a and 37b attached on the left and right sides, and a weak spring 38 is hung on the shaft 37b side for removing the sag and maintaining the posture. 39 is a mirror drive lever, and pin 3 is installed in the mirror holding plate 36.
6a. The mirror drive lever 39 is coaxially rotatably supported by the automatic aperture lever 4 and a shaft 40, and an aperture lever spring 4l is hung between the two via a pin 4a and a pin 39a. Therefore, in normal operation, as is well known, both rotate together around the shaft 40 as the center of rotation. Further, a signal pin 39b for activating a mirror switch S2 for detecting the mirror star 1 is installed at one end of the lever 39, and a roller 42 interlocked with a mirror driving force 45 is rotatably mounted at the other end. It is provided. The spring 43 hung on the pin 39c on the mirror drive lever 39 is a mirror drive spring;
a and 44b are sliding brush contacts of the phase detection switch 4.
4. A rotation limiting pawl 47 is fixed to a gear 46 that is integrated with the mirror driving force 45, and a rotation stopper 4
8, the rotation angle is set to be a little less than one rotation in both clockwise and counterclockwise directions.

The raising and lowering of the mirror is controlled by the rotation direction of motor M2.
2 rotates in the counterclockwise (arrow A) direction, the gear 46 and the mirror drive force arm 45 also rotate counterclockwise (arrow B) via the gears 51, 50, and 49. Accordingly, the roller 42 follows the mirror drive force 45 due to the biasing force of the mirror drive spring 43, and the mirror drive lever 39 and automatic aperture lever 4 are rotated clockwise (arrow C) about the shaft 40. move.

Therefore, as the automatic aperture lever 4 moves, the aperture of the lens l is narrowed down to a predetermined aperture diameter, and at the same time the pin 36
The mirror holding plate 36 interlocks with the mirror drive lever 39 at a.
rotates counterclockwise (arrow D), and the mirror 5 rises from the image observation position to the photographing position.

When the mirror drive lever 39 starts rotating clockwise (arrow C), the pin 39b leaves the position where it presses the mirror switch S2, so the mirror switch S2 is turned ON.
The state immediately switches to the OFF state.

Further, the phase detection switch 44 is in the OFF state when the mirror 5 is lowered and is in the image observation position (shown in FIG. 3).
When the mirror drive lever 39 is slightly rotated clockwise (arrow C), it is immediately turned on.

Furthermore, just before the motor M2 continues to rotate and the rotation limiting claw 47 comes into contact with the stopper 48, that is, just before the mirror drive lever 39 rotates and completes lifting the mirror 5 to the photographing position, the phase detection switch 44 is activated. When the mirror 5 is switched from the ON state to the OFF state again, and the rotation limiting claw 47 comes into contact with the stopper 48 and the rotation of the gear 46 in the counterclockwise (arrow B) direction is stopped, the mirror 5 is in the OFF state.
It is in F state. Next, after the photographic recording operation is completed, when the mirror 5 descends from the photographing position and returns to the image observation position, the motor M2 rotates the gear 46 and the mirror drive force arm 45 clockwise (opposite to arrow 8). Rotate clockwise (opposite to arrow B). The rotation of the cam 45 applies a rotational force in the counterclockwise (opposite to arrow C) direction to the mirror drive lever 39 through the roller 42 against the counterforce of the mirror drive spring 43, which is opposite to the case of raising the mirror. , mirror holding plate 3
6 and mirror 5 clockwise (opposite to arrow D) to lower the mirror to the image observation position. The automatic aperture lever 4 is also rotated counterclockwise (opposite to arrow C) to the image observation position, and the aperture diameter of the lens l is returned to its open state. At this time, the phase detection switch 44 reverses the operation when the mirror goes up, and changes its connection state from OFF to ON immediately after the mirror starts to go down, and again from ON to OFF just before the mirror goes down.

Further, the mirror switch contact S2, which was switched from ON to OFF during the mirror raising operation, is returned from OFF to ON again at the position where the mirror lowering is completed.

On the other hand, the motor M2 has the same rotating shaft protruding from the opposite side of the shaft to which the gear 5l for driving the quick return mirror mechanism and the automatic aperture mechanism described above is attached, and a screw gear 52 is fixed thereto. The rotation of the motor M2 is converted to the right angle direction by the screw gear 53 that meshes with the screw gear 52, and is transmitted to the gears 54, 55, and 56, and then to the rack member 57.
It is transmitted as a reciprocating linear motion. A slide lever pin 57a that engages with a shutter charge pin 35b attached to a charge lever 35a of the shutter 35 is implanted at one end of the rack member 57. In the state shown in FIG. 3, the slide lever pin 57a presses the shutter charge bin 35b and the shutter charge is completed. Further, the rotation of the gear 53 is caused by the rotation of the gear 55 and 1.
It is transmitted to the gear 59a by the gear 58 of the body. gear 59
A cam disc 59b, a roller 60, and a clutch spring 6l are assembled inside the clutch a, forming a one-way rotating clutch. Furthermore, a friction spring 63 that slides in pressure contact with the gear 62 that is fixed on the same axis as the cam disk 59b.
A reverse rotation preventing pawl 64 that rotates is provided oppositely and is set to prevent rotation of the gear 62 (arrow J). A gear 65 is integrally coupled to a shaft opposite to the gear 62, and this rotation is transmitted to a screw gear 68 via a gear 66 and a shaft 67. The screw gear 68 is arranged to drive the moving mechanism of the magnetic head, and uses the above-mentioned one-way rotation reversal prevention mechanism to transmit rotation by a predetermined rotation angle b in one direction for each shot of one screen. It is configured like this.

The shutter 35 shown in this embodiment is a known focal plane shutter mechanism, and is of a type in which the running and opening of at least the leading curtain of the leading curtain and the trailing curtain is triggered by an electric signal. In addition, the switch 35 includes a well-known trailing curtain running detection switch (hereinafter abbreviated as trailing curtain switch) that is turned on just before the trailing curtain completes running, and turned off when the trailing curtain moves to the running preparation position due to the shutter charge. ) is provided.

When the motor M2 rotates in the counterclockwise (arrow A) direction to raise the mirror 5 from the state shown in FIG. The screw gear 53 is a clock (arrow E)
rotated in the direction. This rotation is transmitted through gears 54 and 55 as rotation of gear 56 in the counterclockwise (arrow F) direction,
The rack member 57 that meshes with the gear 56 moves in the direction of arrow G. When the rotation of the motor M2 in eight directions is rotated by a predetermined rotation angle regulated by the rotation limiting pawl 47 and the stopper 48, the slide lever pin 57a moves to the retracted position where the shutter 35 can be operated as the rack member 57 moves. will be moved up to Also at this time, gear 5 meshing with gear 58
9a is also rotated in the clockwise (arrow ■) direction, but due to the action of the one-way rotation clutch mentioned above, it slides between it and the cam disk 59b, and the anti-reverse claw 64 bites into the gear 62, causing the gear 65 to rotate.
rotation is not performed. Next, the shutter 35 operates, the photographing and recording operation is completed, and the motor M2 is activated by the clock (arrow A).
When the quick return mirror 5 is lowered and the automatic diaphragm mechanism is reset, the screw gears 53 and 54 move counterclockwise (opposite to the arrow E) and the gears 55, 56, 58 rotate clockwise (opposite to arrow F). At this time, the shutter charge lever 35a is moved to the H position by the end of the shutter curtain travel.
Therefore, when the rack member 57 is moved in the direction opposite to the arrow G due to the rotation of the gear 56 in the clockwise (opposite to the arrow F) direction, the slide lever bin 5 is rotated again.
7a and the shutter charge pin 35b come into contact, the shutter is charged with running force and returned to the state shown in FIG. 3. At the same time, motor M2 clock (opposite to arrow 8)
The rotation in the J direction is transmitted to the gear 59a via the gear 58 as rotation in the J direction. In this case, the clutch mechanism consisting of gears 59a, cam disc 59b, rollers 60, and clutch spring 61 rotates as one unit due to the wedge effect, until the anti-reverse claw 64 also comes into contact with the pin 64a due to the frictional force of the friction spring 63. It rotates clockwise (arrow K) and does not prevent the gear 62 from rotating. The shaft 67 thereby directs the motor M2 so that the quick return mirror performs a downward movement.
The magnetic head is rotated by a certain angle in the clockwise (arrow L) direction only when the magnetic head rotates, and the magnetic head is advanced by one screen of recording tracks by the configuration described later.

In the embodiment shown in FIG. 3 above, when the shutter release is performed, the shutter is operated to take pictures and record, and then the magnetic head is moved in parallel with the shutter charge when the quick return mirror is lowered. However, the magnetic head may be moved when the mirror is raised. In this case, the rotation of the motor is reversed, so the gear 59a, cam disk 59b, and roller 60
This can be achieved by configuring the one-way rotation clutch mechanism of the clutch spring 6l and the reversal prevention mechanism of the gear 62, the friction spring 63, and the reversal prevention pawl 64 so that the operating effects are in the reverse rotation direction. Furthermore, the rotation direction of the shaft 67 is opposite to the arrow L, but this can also be achieved with the same configuration by changing the helix angle of the screw gear 68 and the screw gear 7l that meshes with it. FIG. 4 (al is a perspective view showing another embodiment of the driving section of the head moving mechanism in the main mechanism part shown in FIG. 3, and FIG. 4(b) is a sectional view of the main part. In the embodiment shown in the figure, the drive mechanism (58 to 68) for moving the magnetic head is set to operate every time the motor M2 rotates after the release and a photographing operation for one screen is performed. In this embodiment shown in FIGS. 4(a) and 4(b), if the shooting/recording operation is not successful, the head do not move,
The drive unit of the head moving mechanism that makes it possible to perform recording on the same track again is shown. The difference between this embodiment and the embodiment shown in FIG. 3 is that in the embodiment of FIG. 3, the cam disc 59b and the gear 65 are integrally fixed to the shaft;
In this embodiment, it is made detachable. Figure 4 (al
As shown in FIG. 3, the transmission is transmitted by the engagement between the rotation pin 65b of the cam disc 59b in the counterclockwise (arrow J) direction and the gear 65a, and this engagement is normally maintained by the biasing force of the spring 70. The cross section of the gear 65a is shown in FIG. 4b.
As shown in , it is configured to be slidable in both the circumferential direction and the axial direction with respect to the shaft of the cam disc 59b, and the plunger PL
When a signal is input to the movable iron core, the gear 65 is driven.
The plunger series lever 69, which is rotatably fitted in the plunger a, moves in the direction of arrow M against the biasing force of the spring 70, and the engagement between the gear 65a and the pin 65b is released. Therefore, when the plunger PL is operated in response to an operation from outside the camera body or a signal detected within the camera body, the shaft 67 is rotated by the gear 66 even if the motor M2 is rotated.
Since sufficient rotational force is not applied to a to disengage the anti-reverse claw 64, it is not rotated. The signal to the plunger PL is set to be given only for a short time at the start when the motor M2 rotates the gear 59a in the direction of arrow J, so the gear 59a and the cam disc 59b rotate by a predetermined angle. Then, due to the lack of force of the spring 70, the gear 65a and the pin 65b are engaged again. In this embodiment, the gear 59a and the cam disk 59b are set to rotate 360 degrees when photographing one screen, and the gear 65a
There is also one engagement groove for engagement with the bottle 65b. Also,
When the plunger PL is operated as described above and the magnetic head is not moved, input to a counter indicating the number of photographed frames, which will be described later, is stopped and the numerical value displayed on the display 8 does not change.

FIG. 5 is a sectional view taken along line III-III in FIG. This shows that.

6 is a perspective view partially showing a part of the head moving mechanism shown in FIG. 5, and FIG. 7 is a diagram showing the operation of gears of the head moving mechanism.

The aforementioned disk rotation motor M1 is placed above the battery 34 on the side of the pentagonal prism 15 in order to downsize the camera. For devices that record or playback, a certain rotation frequency (
For example, 1,800rpm or 3,600rpm)
It is desirable that the magnetic disk (or magnetic head) rotates at a constant speed. In a device that rotates a magnetic sheet, factors that disturb the uniformity of rotation of the magnetic sheet include fluctuations in the load applied to the sheet rotation drive means (motor), vibrations and external forces applied to the device from the outside, Reducing these effects leads to increasing uniform velocity. On the other hand, in the apparatus according to the present invention, by using a motor to directly or indirectly drive the recording track switching mechanism, shutter mechanism, quick return mirror mechanism, automatic aperture mechanism, etc. by moving the magnetic head, quick shooting performance can be improved. The reliability of sequence operations will be improved. If one motor attempts to perform both the rotation of the magnetic sheet and the driving of each mechanism of the camera, the motor becomes large, and in devices such as cameras that require relatively small size, other devices are required. This not only restricts the arrangement of the mechanism and circuit members, but also causes problems such as the load fluctuations of the latter having an adverse effect on the constant speed rotation of the former. Therefore, in the embodiment of the present invention, a motor M1 for rotating the magnetic sheet, which requires constant speed and high-speed response, and a motor M1, which drives each mechanical part of the camera, which mainly requires driving torque, are used.
2 and 2 respectively. Furthermore, the operating mode of the motor M1 and the motor M2 is such that the driven member of the motor M2 repeatedly starts and stops as the photographing sequence progresses, whereas the magnetic sheet rotated by the motor Ml is rotated during the photographing operation. In addition to this, it is desirable for the camera to rotate continuously even during photographic preparation operations in order to improve quick-shooting performance, and it is a good idea to drive both by separate motors. The disk drive shaft 25 connected to the motor Ml by a belt 26 is made of a material and shape having a large moment of inertia since it also functions as a flywheel for maintaining constant speed rotation. A sensor 89 detects and controls the rotational speed and phase of the disk drive shaft 25, and is composed of, for example, a photocoupler consisting of a light emitting diode and a photoelectric conversion element, or a Hall element that detects a change in magnetic point. Therefore, at least one light reflecting portion or magnetic pole is formed on the outer periphery of the disk drive shaft 25 in order to generate speed detection pulses. As shown in FIG. 3, the rotation of the drive motor M2 is the rotation of the screw gear 68 in the counterclockwise (arrow L) direction (clockwise rotation in FIG. 3).
The signal is transmitted to the screw gear 71. A gear 72 coaxially and integrally fixed with the screw gear 7l is a gear whose tooth tips are partially cut out as shown in FIGS. 6 and 7, and meshes with a gear 73.

The gear 73 is integrally fixed to the shaft of the lead screw 77 along with the gear 74 and the ratchet wheel 78. This lead screw 77
The magnetic recording head 30 rotates in the direction of arrow N.
This is for moving the supporting member 86 attached thereto in parallel along the guide axis 87.

A spring 76 is applied to the gear 75 that meshes with the gear 74, which applies a rotational force in the opposite direction to the direction in which the lead screw 77 rotates when sequential photographing is performed from the starting position. For the ratchet wheel 78, a locking pawl 79 as shown in a perspective view in FIG. It is arranged so as to prevent rotation (opposite to arrow N). Further, a lock release lever 82 that can be engaged with one end of the lock pawl 79 on the opposite side of the ratchet wheel is rotatably supported on a shaft 85, and the force of the lock release spring 84 is applied to the clock (arrow 0). biased in the direction. Here, the rotation force of the lock release spring 84 is set to be larger than the rotation force of the lock spring 80, so when the lock release lever 82 rotates clockwise (arrow O), the one end 82a One end 79a of the locking pawl 79 is pressed and held in a position where the locking pawl 79 and the ratchet wheel are always released from each other. However, during normal shooting, as shown in Figure 2 (bl), the release lever 8
The cassette detection pin 83 attached to the tip of the cassette 2
The clock of the release lever 82 comes into contact with the outer part of 0 (arrow O)
Since rotation in the direction is prevented, the tips 82a and 79a
A gap is created between them so that the locking pawl 79 can lock the ratchet wheel 78. Next, the operation of the head moving mechanism for switching recording tracks of the magnetic recording head 30 shown in FIGS. 5 and 6 will be described below. As described above, the screw gear 68 rotates in a certain direction (in the direction of arrow L) during a predetermined operation of the camera's photographing operation sequence (in the embodiment of the present invention, when the mirror is lowered and the shutter is charged), and as a result, the gear 72 rotates in the direction of the arrow L. Rotate by a certain angle (120°) in the M direction. Here, the gear 72 is configured, for example, as shown in FIG. 7, in the form of a gear with a total number of nine teeth, with one tooth left every three teeth at equal intervals, and the gear 73 is configured with a spur gear with the number of teeth lO. . When the gear 72 is not receiving the rotational force from the screw teeth and the wheel 68, it is in the position (■) in FIG. 7(i) and does not mesh with the gear 73. At this time, if the cassette is not inserted into the camera, the gear 73 is at the start position because the spring 76 applies a rotational force to the lead screw 77 in the opposite direction to the feeding direction (arrow N direction). When the cassette is inserted, the ratchet wheel 78 and the locking pawl 79 are engaged, so the ratchet wheel 78 is engaged at a position moved by a certain number of teeth from the start position (the starting position immediately after the cassette is inserted). It has been stopped. Now gear 7
Since the number of teeth of the gear 73 and the ratchet wheel 78 are set to be the same (10 teeth), the position of the gear 73 is the same regardless of whether a cassette is inserted or not, that is, the teeth of the ratchet wheel sent from the start position are the same. Figure 7 (i
) is located at ■ position. Next, when the gear 72 receives rotation from the screw gear 68 due to the operation of the motor M2 mentioned above, the gear 72 starts rotating in the direction of the arrow M, meshes with the gear 73 at the position (■) in FIG. 7(i), and further ( After passing through the position (ii) (■), the rotation continues and the rotation is performed by a predetermined angle. In the embodiment of the present invention, the gear 72 is rotated by 120 degrees due to the photographing operation of one screen.
In other words, the motor M2 rotates by one tooth with the remaining teeth.
The number of teeth of the gears from 68 to 7l is set. Therefore, the tooth 72 rotates from the position ``■'' to the position ``■'' in FIG. 7(iii), but on the way, it disengages from the gear 73 at the position ``■''. The tooth 73 is rotated approximately 45 degrees in the direction of arrow N from the position of ■ in the state shown by ■, but when it is disengaged from the gear 72, it is rotated in the direction opposite to the direction of arrow N by the force of the spring 76. At this time, if the cassette is inserted into the camera, the ratchet wheel 78 will move by one tooth (3 teeth).
6 degrees), it rotates in the opposite direction and engages with the locking pawl 79 by the force of the spring 80, and is rotated by one tooth of the gear 73 and ratchet wheel 78 at the position ■''. Stop. This completes the feed operation for one screen and returns to the state shown in ■. Therefore, lead screw 7 is required for each photographed frame.
7 is rotated by l/10 rotation (36°), and the magnetic recording head is rotated by 1/10 of the lead pitch of the lead screw 77 (
For example, if the lead pitch is Lmm, the distance is moved by 100 μ), which corresponds to the pitch of the recording track. Also, if the cassette is not inserted during the above operation, or if the cassette is removed after shooting a predetermined number of frames,
As described above, since the engagement between the ratchet wheel 78 and the locking pawl 79 is released, the support member 86 of the magnetic recording head 30 is returned to the starting position by the force of the spring 76.

Reference numeral 88 is a restriction bottle that comes into contact with the support member when it returns to the start position to regulate the start position, and is adjustable and attached to the support board l9 of the camera body. S3 is an electrical contact that contacts one end of the release lever 82 and is linked to the operation of the detection bin 83 depending on whether or not a cassette is inserted.
This is for returning the numerical value displayed on the aforementioned piece number counter to 0 in response to rotation in the direction of arrow 0). Because of this arrangement, the magnetic recording head returns to the starting position when the cassette is removed, regardless of the number of frames to be photographed, and the counter display also becomes 0. In an electronic recording still camera like the device of the present invention, which sequentially records video signals on multiple recording tracks of a disc-shaped magnetic sheet,
The mechanism that moves the magnetic head to switch recording tracks is
It becomes more useful by not only simply moving the track position by a predetermined amount (for example, 1 track) each time a screen is photographed, but also by being able to handle the exchange of a plurality of magnetic sheet cassettes. Therefore, the magnetic head moving mechanism is configured to move the head one track at a time for each shooting operation of one screen, and at the same time, when the cassette is replaced, it returns to the starting position among all the recording tracks and starts recording again from there. It is effective to do so. On the other hand, the magnetic head is moved by motor drive,
The same motor is used to operate various mechanisms related to camera exposure (
(Quick return mirror mechanism, automatic aperture mechanism, shutter charge mechanism, autofocus mechanism, etc.), the head movement mechanism of a well-known magnetic disk device is simply added to a conventional still camera with a built-in motor. If we just added a motor, returning the head to the starting position when changing the cassette would be extremely complicated as it would have to be linked to the drive parts of each mechanism in the camera. . Further, if the head moving mechanism is operated in the reverse direction by a motor, it takes time to return the head, which has the disadvantage of impairing quick shooting performance. Therefore, in the present invention, the movement mechanism of the magnetic head is driven by the drive motor of each mechanism of the camera in the forward direction only, and at the same time, each time the movement of one screen is completed, the motor and head movement mechanism Since the head is configured to break the locking, it is now possible to return the head to the starting position from a track position of any number of frames. Furthermore, since the head support member is returned to its original position by a spring that urges it toward the starting position,
Another advantage is that the head can be returned quickly after replacing the cassette. This spring also has the effect of suppressing positional variations due to backlash in the head moving mechanism and achieving highly accurate head movement. As described above, by using the head moving mechanism as shown in the present invention, it is possible to drive both the mechanical parts of the camera and the head moving mechanism with a single motor, making the electronic recording still camera smaller and more compact. It can be manufactured at low cost.

Next, the release button and mode switching ring section will be explained with reference to FIGS. 8 and 5.

FIG. 8 is a perspective view showing in detail the relationship between the mode switching ring and the release button in FIG. 5.

In FIG. 8, 95 is a click spring of the mode switching ring 7, and a sliding brush 94a constituting the mode switching switch is fixed to the ring 7.

In the state shown in FIG. 8, the mode switching ring 7 is set to the single frame shooting mode, and when the mode switching ring 7 is turned counterclockwise, the brush 94a slides on the changeover switch board 94b, and the mode is switched to the continuous frame shooting mode. It will be done. Conversely, turn the mode switching ring 7 clockwise from the state shown in the figure (OFF
) position, the lower protrusion 7a of the ring engages with one end 91a of the switching lever 9l rotatably supported on a shaft 92, rotating the switching lever 91 counterclockwise. As a result, the other end of the switching lever 9lb enters the lower notch 6a of the release button 6 and prevents the release button 6 from being depressed by a predetermined stroke. Further, a pin 90 attached to the other end of the switching lever moves the cassette holder 23 by a very small amount from the position shown in FIG.

Therefore, by setting the mode switching ring 7 to the (OFF) position, you can not only lock the pressing of the release button and prevent failures in shooting or power consumption due to pressing the release button 6 inadvertently, but also When a cassette is left unused for a long period of time with a cassette in its place, it is necessary to prevent the magnetic recording head from adhering to the magnetic disk, and especially when the magnetic recording medium is a flexible sheet, to prevent deformation of the sheet and prevent deterioration of recording. Failure can be prevented. Note that at this time, the amount by which the bin 90 pushes the cassette holder 23 and moves the cassette 20 is small, and the detection bin 83, lock release lever 82, and switch S3 that determine the presence or absence of a cassette are
It is set so that it has no effect on the Reference numeral 93 is a spring for returning the lever 9l, and holds the switching lever 91 in the non-operating position when set to the S mode or the C mode. When the mode switching ring 7 is set to the S (single frame shooting) mode and the C (continuous frame shooting) mode for normal shooting, it slides in conjunction with the depression of the release button 6, as shown in Fig. 5. Lever 96 moves downward against spring 97. At this time, in the middle of a predetermined release stroke, the pin 96a attached to the lever 96 first closes the ready switch S4, and by further pushing the release button 6, the pin 96b closes the release switch S5.

The ready switch S4 operates the exposure meter circuit and the display circuit in the viewfinder of the camera before starting the shooting operation.
Furthermore, it is used to perform preliminary rotation of the magnetic disk by the motor M1, and when the release switch S5 is opened, the photographing sequence of the camera is started and the power of the motor M2 is turned on.

S6 is a contact that operates in conjunction with the recording/non-recording switch 9, and when S6 is opened, the recording circuit from the magnetic head 30 to the magnetic disk 20 becomes inactive. 98 is a click spring of the changeover switch 9.

Margin below Now, next, a sequence control system applied to the configuration described above will be explained with reference to the following figures.

FIG. 9 is an operation time chart of the embodiment of the present invention.
Figure O shows a write enable/disable signal generation circuit block for detecting rotational fluctuations of the magnetic disk, and Figure 11 shows a sequence control circuit block of the main mechanism. As in the present invention, the magnetic disk is rotated at a constant speed and once per revolution of the track.
In a device that records an image signal for a field or one frame, the recording disk must always rotate stably when taking a still image and recording it from the image sensor to the magnetic disk. When this device is used as a portable device, the ready switch S4 is turned on by pressing the shutter release button halfway, and recording is not possible until the magnetic disk is rotated at a constant speed by the motor M1 immediately after the power is turned on. It is not enough to just send out a signal indicating that the camera is moving.For example, when taking panning shots or taking pictures from a moving car, vibrations can cause a large disturbance and cause the motor M
There may be cases where the variation in rotational speed due to l exceeds the permissible value. The block diagram shown in FIG. 1O is a circuit for detecting rotational fluctuations even in such a case.

The roles of the two jitter measuring circuits shown in FIG. 1O will be explained below. First, in the l-field jitter measurement circuit, for example, when the rotation of the disk drive shaft 25 has not yet reached a constant speed, such as when the motor Ml is started, the amount of jitter is determined during a period in which there is a large phase error over one field or within one field. The amount of jitter is measured over a certain period of time, and if the phase error exceeds the allowable value as a result of integrating the jitter amount, a recordable signal is generated.To realize this circuit, for example, Motor Ml
a pulse generator 8 that generates a plurality of pulses based on the rotation of the
PG (Frequency Genera)
tor) signal and the synchronization signal generation circuit built into the camera +
By comparing the phases of the FC signal obtained from the FC signal 20 and the synchronization signal 202 having approximately the same frequency, the phase difference between the two is determined using a sufficiently high frequency clock obtained from the clock pulse generator 101, and the accuracy of the frequency of this clock is determined. This detects the phase difference as the amount of jitter, and this detected clock is continuously counted over one field by a jitter measurement circuit for each field, and this count is determined as a predetermined number. If the jitter exceeds 1, the jitter is too large, and the recordability signal 206 is output as NO.Furthermore, this l-field jitter measurement circuit 102 is reset immediately after the start of l-field to measure the jitter for each l-field. It becomes possible to measure the size of.

Next, the l-field jitter measurement circuit 103 will be explained. As mentioned above, in the case of this device which is used in a portable manner, even after the disk rotation motor M1 has reached a constant speed, there is a possibility that a large disturbance may be momentarily applied to the disk rotation motor M1. A large phase jump appears only for a very short period of time within one rotation of the drive shaft 25, and in this case, it cannot be corrected completely by AFC or the like during playback, resulting in an unsightly playback screen. Therefore, it is necessary to monitor even very short phase jumps within one revolution, and this is the circuit that realizes this. If used, this FG
The clock cycle may be measured every time, the time difference with the previous cycle may be detected as a jitter amount, and if this exceeds a tolerance value, a warning signal may be output.

Then, the output of the jitter measurement circuit 102 for each field and the output of the intra-field jitter measurement circuit 103 are ORed.
The signal is input to the circuit 104 and constitutes a recordability detection means which outputs a recordability signal if any one of the warning signals from the two types of jitter measurement circuits is output. or,
Even if recording is in progress, if a NO recordability signal is output, the track is not moved and recording is performed again on the same track during the next photographing. Note that the optimum value of the above-mentioned jitter tolerance may be determined depending on the AFC characteristics of the playback device.

Furthermore, both of the above-mentioned two types of jitter measuring circuits are not necessarily required, and depending on the cause of jitter, it may be sufficient to use only one of the measuring circuits.

Next, an outline of the operation sequence in the embodiment of the present invention will be explained with reference to FIGS. 9 and 11. When performing normal shooting and recording, the recording/non-recording switch 9 is set to record (
Rec) position and S6 is turned ON. First, ready switch (SW) S4 linked to the release button (6)
turns ON, and the release and ready signal generation circuit (116
) transmits a disk rotation start signal (204) to the magnetic recording system (hereinafter simply referred to as the recording system), and the motor M1 starts rotating the disk. As mentioned above, the recordability signal (206) does not become Yes until the disc rotation reaches a constant speed and recording is possible, so press the release button (6) and release the release SW' (S) in conjunction with it.
5) is ONL, the release ready signal generation circuit (116
), the release signal (20B) is not generated. After the recording permission signal (206) generates Yes, release SW (
By turning on S5), the release ready signal generation circuit (116) generates a release signal (208).

When the release signal (208) is generated, the motor drive timing control circuit (119) controls the motor drive circuit (121).
) to rotate the motor (M2). At this time, the motor rotation direction control circuit (122) generates a signal to rotate the motor M2 counterclockwise. As mentioned above, the mirror begins to rise due to the drive of motor M2,
Mirror SW (S2) is OFF, mirror phase SW (4
4) turns on. The mirror SW (S2) is the lens (1
) generates an aperture value signal and a signal for storing the photometric value of the photometric calculation control circuit (+08) which receives luminance information from the light receiving element (+00). Also, mirror SW (S2)
The ON and OFF signals are counted by a photographed frame number counter (111), and the photographed frame number counter display 112 also displays the number of photographed frames.

(108) is an exposure calculation control circuit that calculates appropriate exposure and controls the shutter shutter's rear curtain, but it is also possible to generate a manual shutter time from the shutter speed setting circuit (113). The shutter speed or aperture value is displayed in the viewfinder or the like by a display circuit (114). When the mirror completes its upward movement, the mirror phase SW (44) is turned off. In synchronization with this signal, the motor drive timing control circuit (119) stops the motor (M2).

This allows the shutter (35) to run at any time, but the image sensor (31a)
By this point, unnecessary charges must be discharged to prepare for shutter activation. This is done as described below.

In the case of a CCD, an overflow control gate is controlled to discharge unnecessary charges in synchronization with a vertical synchronization signal immediately after the release signal is generated. Furthermore, if it is an element such as a MOS, a clock signal for the sensor is generated to reset each element. They are sensor timing control circuit (11
Image sensor drive circuit (1) based on the output signal of (7)
10). Further, drive pulses are generated by a drive pulse generation circuit (118), and basic synchronization signals are generated by a synchronization signal generation circuit (120). And this unnecessary charge discharge state is the shutter (35)
This continues until just before the opening operation begins. Now, the shutter (35) is now ready to open at any time.

When the shutter timing control circuit (115) detects this state, it sends a signal to open the shutter in synchronization with the vertical synchronization signal to the shutter drive circuit (109), the exposure calculation control circuit (108), and the sensor timing control circuit (117).
tell to. The image sensor stops discharging unnecessary charges and the shutter begins to open.

The exposure calculation control circuit (108) starts counting the shutter seconds in response to the shutter open signal. The image sensor is then fully exposed.

An exposure calculation control circuit (108) calculates a shutter time that provides proper exposure, or transmits a trailing curtain start signal to a shutter drive circuit (1.09) at a manual shutter time set by a shutter speed setting circuit.

The trailing curtain starts, and at the same time as the running is completed, a trailing curtain signal is output to notify the end of exposure to the circuit blocks of the motor rotation direction control circuit (122) and recording control signal generation circuit (123). The motor M2 rotation direction control circuit (122) outputs a signal to the motor drive circuit (121) to drive the motor M2 clockwise in response to a synchronization signal immediately after the trailing curtain signal is generated.

Furthermore, when the recording control signal generation circuit (+23) receives the trailing curtain signal, it outputs a signal charge in the image sensor in synchronization with the next synchronization signal, but the energy when the shutter trailing curtain stops is transferred to the camera body. If the vibration is transmitted to the main body and the recording system is disturbed and recording becomes impossible, the recording permission signal (206) generates NO, so no signal charge is generated and the signal is transferred to the image sensor. keep it.

When the state is such that vibration has no effect, (206) becomes Yes, and in synchronization with the next synchronization signal, the sensor timing control circuit (117) and sensor drive circuit (110)
operates and outputs a signal charge. The signal output from the image sensor is amplified by a pre-amplifier (105), converted into R, G, and B color signals by a color signal separation circuit (106), and then passed through a process circuit (107) for processing such as black level clamping and waveform shaping. is added and the recorded video signal output (20!
) and is input into the recording system. At the same time as the recording control signal (205) from the recording control signal generation circuit (123) ends, the motor M2 drive timing control circuit (+19)
The motor M2 starts rotating clockwise by the output of the motor M2 and the rotation direction signal from the motor rotation direction control circuit (+22). The motor M2 starts lowering the mirror, and at the same time charges the shutter and moves the magnetic head to track.

As the mirror descends, the mirror phase SW (44) becomes O.
NL, it turns OFF just before the descent is completed. Mirror SW (S2
) had been OFF until now, but now it is ON due to the lowering of the mirror.
becomes.

When the mirror SW (S2) is turned ON and the mirror phase SW is turned from ON to OFF, the motor drive timing control circuit (119) stops the rotation of the motor.
A signal is sent to the release/ready signal generation circuit (+16) to reset the release signal (208).

The motor rotation direction control circuit (122) is in a state to output a signal to the motor drive circuit (121) so that the rotation direction becomes counterclockwise in response to the end of the trailing curtain signal and the next synchronization signal after the end of motor rotation. .

This ends the shutter sequence and prepares for the next release signal.

Also, when the energy of the shutter's trailing curtain stops running at the end of the exposure mentioned above, it is transmitted to the body as vibration,
The bad thing is that when other vibrations are transmitted and the recording system is disturbed and recording becomes impossible, the image sensor does not output a recording signal output, and outputs it only after it becomes recordable, but the recording system quickly recovers. For example, if the image sensor recovers after a few ws to about 10-odd ws and becomes capable of recording, the signal charge inside the image sensor will be large due to the generated dark current, and the S/N ratio will not drop, so a recording start signal will be output and recording will start. conduct.

However, if the recovery of the recording system is delayed, for example by two fields or more, the S/N ratio of the signal charges held in the image sensor will drop significantly due to dark current. Therefore, when a preset time has elapsed after the trailing curtain signal is generated, the recording control signal (205) is not output, and the motor drive timing circuit (119) drives the motor M2 to lower the mirror and charge the shutter. , completes the shatter sequence. (In this case, since there is no recording, there is no need to move the recording head. Therefore, the head-feed prohibition signal (203) is generated, the magnetic head is not moved by the above-mentioned configuration, and the photographed frame number counter signal is also (This does not occur.) In this case, since photographing and recording could not be performed, a warning signal is displayed to the photographer. Note that a warning signal is similarly displayed to indicate that the release cannot be performed until the disc starts with the disc rotation start signal 204 and the disc rotation becomes constant and recording becomes possible.

Now, the operation sequence described so far is for normal shooting and recording, but the magnetic recording head is moved to the position corresponding to the arbitrary number of shooting frames (
In other words, if you want to record only that number of frames or after that number of frames (by performing a jump feed), you can do so by setting the recording/non-recording switch 9 to the non-recording (NR) position. . When the selector switch 9 is set to the non-recording position and S6 is turned off, after pressing the release button,
Regardless of the recordability signal (206), the recording control signal generation circuit (123) operates so that a release signal is immediately generated from (116). Furthermore, when the mirror is raised and the shutter is moved, a recording control signal (205) is issued regardless of the recording permission signal (206), and the recording video signal output (201) is not generated and the motor M is
2 rotations are performed, and a shirt start charge, mirror down, head movement, and number of pieces are counted. After repeating this operation and moving the magnetic head without recording images up to the desired number of frames, the selector switch 9 is moved to the recording position (Re
By returning to c), the image will be displayed on the counter 8 at that time, and normal shooting and recording will be possible again.

As described above, according to the present invention, it is possible to downsize an electronic still camera that records still images on an electronic recording medium.

[Brief explanation of drawings]

Fig. 1(a) is a front perspective view showing the external appearance of a camera body incorporating an embodiment of the device of the present invention, Fig. I(b) is a top external view of the device, and Fig. 2(a) is a Figure 1 (a) is a cross-sectional view of I-■, Figure 2 (bl is a cross-sectional view of Figure 1 (bl is n-■ cross-sectional view, Figure 3 is a perspective view of the main mechanism, 3 is a perspective view showing another embodiment of the driving section of the head moving mechanism among the main mechanical parts shown in FIG. Diagram (■1■ of bl)
6 is a perspective view of the main parts of the magnetic head moving mechanism shown in FIG. 5, FIG. 7 is a plan view illustrating the operation of the mechanism shown in FIG. 6, and FIG. 8 is a mode switching ring shown in FIG. 5. FIG. 9 is a timing chart showing the relationship between the operation of the main components of the device of the present invention and the output of the control circuit, and FIG. 10 is a disc-shaped device applicable to the device of the present invention. Block diagram of a rotational speed control accuracy detection circuit for a magnetic recording medium. FIG. 11 is a block diagram of an operation sequence control circuit of the apparatus of the present invention.

Claims (2)

[Claims] (1) In an electronic still camera that records an image formed on an image sensor as a still image signal, an optical low-pass filter, a focal plane shutter, and an image sensor are arranged in the above-mentioned order in the photographing optical path to create a focal point. An electronic still camera characterized by a plain shutter and an image sensor placed close together. (2) The electronic still camera according to claim 1, characterized in that an optical low-pass filter is disposed in a space sandwiched between a reflective mirror of a single-lens reflex finder and a focal plane shutter.