JPS6361568A - Still video camera - Google Patents

Abstract

PURPOSE:To reduce occurrences of erroneous recording, check errors, etc., by prohibiting at least the driving of the electro-mechanic driver of an exposure system that includes a shutter dirver during the period of the recording of still video signals from a magnetic head on a magnetic disk. CONSTITUTION:If the exposure controller 40 informs the opening and closing of a shutter 46 to a main controller 30, the recording of picked up still video signals are recorded in the magnetic disk 11 during the following one period of a vertical synchronizing signal VD. Then recording command REC stops, and a reproducing/recording switching circuit 24 returns to reproduction-side. During the following one period, a recording check processing is executed. At the time of recording FM-modulated video signals on the magnetic disk 11 by the magnetic head 21 and of recording processing following said recording, any action of the shutter 46, mirror 45, or diaphragm 44 is not executed. Therefore, the occurrences of mechanical oscillation due to said actions, a flucture in power supply voltage due to the driving by drivers 41 and 42 including the shutter driving motor and diaphragm driving motor, and of noise, are prevented, and thus a favorable condition for the recording of video signals and recording check is maintained. As a result, erroneous actions in these operations are suppressed of occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Summary of the Invention Shutters, mirrors, apertures, etc. produce mechanical vibrations during their operation. Furthermore, since the battery of a still video camera has a small capacity, the power supply voltage fluctuates when a drive device such as a Nyatta drive motor is driven.

Furthermore, these drive devices generate phenomena such as noise, which adversely affects the writing of still video signals onto the magnetic disk. Therefore, driving of the above-mentioned exposure system driving device is prohibited at least during the recording period of the video signal. In a device in which a recording check is performed after recording a video signal, it is preferable to prohibit the "double drive" also during this recording check process.

Background of the Invention This invention relates to a still video camera (electronic still camera) that photographs a subject with an electronic imaging device and records the still video signal on a rotating magnetic disk.
Regarding.

The exposure system of a still video camera is provided with mechanisms and drive devices that generate mechanical vibrations, power supply voltage fluctuations, noise, and the like. for example.

A drive motor for charging the shutter and shutter spring, an aperture drive motor for cameras with automatic exposure control, a mirror for deflecting incident light for cameras equipped with a single-lens reflex viewfinder, and an automatic focus adjustment (auto) Examples of devices with a focus function include automatic focus drive devices and the like. The shutter generates mechanical vibrations when it opens and closes, and the mirror generates mechanical vibrations when it moves up and down. Since the battery built into a still video camera has a relatively small capacity, the power supply voltage tends to fluctuate when the drive motor is driven. Furthermore, driving the motor tends to generate noise.

A still video camera records still video signals representing the photographed subject on a magnetic disk, and the touching between the magnetic disk and the magnetic head is extremely delicate, and the track spacing on the magnetic disk is relatively small. narrow. Furthermore, since one frame of still video signals is recorded per rotation of a small magnetic disk, extremely high-density magnetic recording is required.

Therefore, when recording still video signals onto a magnetic disk using a magnetic head, in order to prevent erroneous recording,
It is preferable to avoid mechanical vibrations, power supply voltage fluctuations, noise generation, etc. as described above as much as possible.

There is also a type of still video camera that records a video signal on a magnetic disk and then checks whether the video signal has been properly recorded. In such a camera, it is desirable to eliminate the above-mentioned adverse factors also during this recording check.

SUMMARY OF THE INVENTION An object of the present invention is to enable recording of at least still video signals onto a magnetic disk under as favorable an environment as possible.

The present invention provides a still video camera in which a still video signal from an imaging device is recorded on a rotating magnetic disk by a magnetic head, at least during the recording period of the still video signal on the magnetic disk by the magnetic head. The present invention is characterized in that it includes a control means for prohibiting driving of an electromechanical drive device of an exposure system including at least a shutter drive device. Prohibiting the driving of the electromechanical drive device means that in a program-controlled still video camera equipped with a CPU, the electromechanical drive device is programmed not to operate during the recording period of the still video signal. In addition, in a camera controlled by a logic circuit, "2.;C! This includes sequencing the electromechanical drive so that it does not operate.

A still video camera with an automatic exposure function uses an aperture drive device, a camera with a mirror that guides incident light to the viewfinder uses a mirror drive device, and a camera with an automatic focus adjustment function uses an autofocus drive device. Preferably, each of these is included in the electromechanical drive device.

Furthermore, in a still video camera of the type that performs recording check processing after recording processing of still video signals, it is preferable to prohibit driving of the electromechanical drive device of the exposure system even during the recording check processing period. .

As described above, according to the present invention, mechanical vibrations, power supply voltage fluctuations, noise generation, etc. are prevented during the recording period of still video signals on the magnetic disk and, if necessary, during the subsequent recording check period. Since we do our best to avoid the actions that cause the problem, it is possible to record and check the recording of video signals under suitable conditions, thereby preventing erroneous recording.

The occurrence of check errors, etc. will be reduced.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 schematically shows part of the electrical configuration of a still video camera having a continuous shooting mode.

The magnetic disk 11 is housed in a disk pack that rotatably accommodates it. Still/Video/
The camera is provided with a packet that can be opened and closed, and a disk back is inserted into the opened packet, and when this packet is then closed, the magnetic disk 11 is chucked to the spindle of the disk motor 14. .

A plurality of (for example, 50) tracks (for example, a track pitch of 100 μm) are provided concentrically on the magnetic disk 11, and are formed by photographing processing.

One field or one frame (one frame) of FM-modulated color video signals (including a luminance signal, nine color difference signals, etc.) is magnetically recorded on each track.

The 50 tracks provided concentrically on the magnetic recording surface of the magnetic disk 1 are numbered in order from the outside.
Rack numbers from 1 to 50 are assigned. The home position HP (original position or standby position) is located outside the No. 1 track, and the end position EP is located inside the No. 50 track.

The operation of each part of the still video camera other than those related to exposure such as the aperture, mirror, shutter, etc., which will be described later, and the overall operation are supervised by the main controller 3o. This main control device 30 is composed of a central processing unit, preferably a microprocessor (hereinafter referred to as CPU), a memory that stores its programs and necessary data, and an interface with each peripheral element circuit, device, etc. ing.

a magnetic disk 110'), a magnetic head 21 for writing a still video signal of an imaged object onto a predetermined track;
The magnetic disk II
It is supported so as to be movable in the radial direction of the radial direction, and its transfer is controlled in the same direction. The main controller 3o gives instructions regarding the direction and amount of movement of the magnetic head 21 to this transfer drive control device. The magnetic head transfer drive control device includes a step motor 22 and its drive circuit 23.
The magnetic head 21 is moved in proportion to the rotation angle of the motor 22. For example, each drive pulse of the step motor 22 rotates the motor 22 by about 15 DEG, thereby moving the magnetic head 21 by about 4.2 .mu.m. therefore.

The transport of the magnetic head 21 is carried out with great precision.

In order to improve the contact between the magnetic head 21 and the rotating magnetic disk 11, a regulating plate (path shown) is provided on the opposite side of the magnetic head 21 with the magnetic disk 11 in between. Further, the core of the magnetic disk 11 is equipped with a magnetic disk 11 that detects the leakage magnetic flux of the permanent magnet for chucking.
A phase detector 12 that outputs a phase detection signal when the angle reaches a predetermined angular position is located nearby. The output detection signal of this phase detector 12 is waveform-shaped by a waveform shaping circuit 13 and output as a phase detection pulse PG. Phase detection pulse PG
occurs once every rotation of the magnetic disk 11. This phase detection pulse PG is the servo control circuit 17
．． Switching control circuit 25. The signal is sent to the main controller 3o and the clock signal generation circuit 6o.

Disk motor 14 is driven by its drive circuit 16. The number of rotations of the disk motor 14 is detected by a frequency generator 15, and a detection signal with a frequency proportional to the number of rotations of the motor 14 is input to a servo control circuit 17. The servo control circuit 17 rotates the motor 14 at a constant number of rotations (for example, 3, 600
Rotate at a constant speed with r, p, m,).

The rotational phase is also controlled so as to be synchronized with the pulse PG. Also the servo control circuit 17. The motor 14 is started and stopped according to commands from the main controller 30.

The reproducing/recording switching/amplifying circuit 24 is normally set on the reproducing side, and amplifies the FM modulated m1 video signal read by the magnetic head 21. This amplified video signal is sent to envelope detection circuit 2B. This reproduced video signal is used for track search processing, checking processing, and the like. On the other hand, the video signal representing the still image of the photographed subject is processed by the recording signal processing circuit described later.
After various processing including l/1 modulation and the like has been added, the signal is manually inputted to the reproduction/recording switching/amplifying circuit 24. Main control device 3
0 outputs the recording command REC, the switching control device 425
is the input phase detection pulse, circuit 2 at the PG timing
4 to the recording side. Then, the processed video signal is amplified by this circuit 24 and then applied to the magnetic head 21, so that the still video signal is recorded on a predetermined track of the magnetic disk 11. This recording is performed only while the magnetic disk 11 rotates once. That is, the control circuit 25 switches the circuit 24 to the recording side only during one period of the pulse PG.

The envelope detection circuit 26 is a detection circuit that detects the read signal of the magnetic head 21, that is, the envelope of the FM modulated video signal recorded on the track of the magnetic disk 11, and outputs a voltage signal corresponding to the envelope. It is. The voltage signal representing the envelope is analog-to-digital converted into an 8-bit digital signal representing a quantization level of, for example, 25G and then sent to the main controller 30.
Enter.

The envelope detection signal is used by the main controller 30 to determine whether a track on the magnetic disk II is unrecorded or recorded (track search processing).

If the level of the detected signal does not reach a predetermined threshold level when the magnetic head 21 is moved across a track, that track has not yet been recorded, and if it has reached the threshold level. The track has already been recorded. The envelope detection signal is also used in the recording check process. The recording check process is a process of recording a photographed still/video signal on a predetermined track as described above using the magnetic head 21, and then checking whether or not this recording has been properly performed.
If the envelope detection signal is above a predetermined threshold level, it is determined that recording has occurred. The envelope detection signal is not at the above threshold level! In the case of I, it is determined that there is a recording error, and for example, the oscillator 32 is driven to cause the buzzer 33 to sound to notify that fact.

In this embodiment, the shutter release button 31 is of a two-step stroke type, and the first step of pressing turns on the switch S1, and the second step of pressing the button 31 turns on the switch S2. When the switch S1 is turned on, main power is applied to each part and the disk motor 14 is driven. Thereafter, when the switch S2 is turned on, a photographing operation is started as described later.

The imaging optical system includes an imaging lens system 43 including an afocal lens, a mask lens, etc. for forming a subject image.
．． Aperture 44. Shutter 46. It is composed of a mirror 45 and the like for reflecting a subject image onto a viewfinder 47 including a penta prism.

Further, a photometric probe 48 for detecting the illuminance of incident light, such as a silicon photodetector, is provided, and a tM is configured such that a part of the light split from the imaging lens system 43 is incident on this element 48. Ru. 711+optical element 4
The illuminance detection signal No. 8 is input to the exposure control device 40 .

The exposure control device 40 includes: a process of calculating an aperture value and a shutter speed based on the incident light illuminance detected by the separately sold element 48, control of the aperture 44 based on the determined aperture value, and shutter control based on the shutter speed also determined. 4G
The opening/closing control of the mirror 45 and the up/down control of the mirror 45 are performed. This exposure control device 40 also. CPU,
It consists of memory, interface, etc.

The main control device 30 and the exposure control device 40 are connected by a bus, and their CPUs operate synchronously while exchanging control signals, data, etc. with each other. One of the typical signals sent from the seed control device 30 to the exposure control device 40 is the release signal R82.

Jack 46 is Focal Plain Nyatta,
It is equipped with springs to run the front and rear curtains. These springs are precharged so that they can exert their biasing force (i.e., extended by pulling in the case of tension springs), and are opened and closed by electromagnets by unlatching them. It is the type that can be used.

Such charging of the spring of the shutter 46 is performed by a drive motor included in the drive device 42. This drive device 42 further drives the energization of the electromagnet of the shutter 46, the up/down of the mirror 45, etc. Adjustment of the aperture amount of the aperture 44 is performed by another drive device 4I including an aperture drive motor. These drives 41 , 42 are controlled by an exposure control device 40 .

The clock signal generation circuit 60 generates clock pulses of multiple types of high and low frequencies, and operates in the servo control circuit 1 described above.
7. Main controller 30. and DPSK (Dirrrc
ntial Phase 5hfft Keying
; difference position shift female tone) is sent to the circuit 57. This phase circuit 60 also generates vertical, water, and l' synchronization signals for one field scan during one cycle of the pulse PG in synchronization with the phase detection pulse PG. These synchronization signals are transmitted to a vertical synchronization drive circuit 61 and a horizontal synchronization drive circuit 6, respectively.
Sent to 2.

At the focal plane of the imaging optical system, a solid-state imaging device (indicated generally by 50) for three primary colors, which is composed of a two-dimensional imaging cell array such as a CCD, is arranged. R (red), G (green), and B (blue) filters are provided in front of the imaging device for each primary color. The video data stored on these imaging devices when the shutter 46 was opened.

By driving the imaging device by the above-mentioned synchronous drive circuits 61 and 62, serial still video signals (R, G
, B), and the preamplifier circuit 51. The signals are input to a process matrix circuit 53 via a variable gain amplifier circuit (color balance adjustment circuit) 52. This circuit 53 generates a luminance signal Y and two color difference signals RY and BY. These color difference signals R-Y, .B-Y are then line-sequentialized for each IH in a line-sequencing circuit 54. Luminance signal Y
The line-sequential color difference signals then pass through a pre-emphasis circuit 55 and are FM-modulated in different frequency bands (FM modulation circuit 56). On the other hand, data other than the video signal output from the main controller 30 is modulated by the DPSK circuit 57, and is sent to the combining circuit 5 along with the above-mentioned FM modulated video signal.
8 and is manually input to the reproduction/recording switching/amplification circuit 24. At the time of recording switching, this FM-modulated and synthesized still/video signal for one field is sent to the magnetic disk 1 by the magnetic head 21 while the magnetic disk 11 rotates once.
As described above, the data is recorded on one predetermined track.

Now, the imaging and recording operations of such a still video camera will be explained with reference to the time chart shown in FIG.

In FIG. 2, VD is a vertical synchronization signal, and its one period (i.e. lV:V is the vertical scanning period) is one in this embodiment.
/60 seconds. Further, this signal VD is delayed by 7H from the phase detection pulse PC (H is the horizontal scanning period). It is assumed that the spring of the shutter 46 is charged in advance.

When the main control device 30 receives the ON input of the switch S2, this device 30 outputs a recording command RFC, and
A release signal R8° is sent to the exposure control device 40. Then, the exposure control device 40 reads the photometric illuminance of the photometric element 48 and determines the aperture value and shutter speed. Also, the drive device 4
2 and raise the mirror 45. Next, the aperture motor of the drive device 41 is driven based on the determined aperture value to perform aperture control. When the aperture control is completed, the nyatta 4G is opened and closed through the drive device 42 based on the determined nyatta speed.

When the exposure control device 40 notifies the main control device 30 that the shutter 46 has been opened or closed, the primary vertical synchronization signal VD
Recording of the photographed still video signal onto the magnetic disk 11 is performed in one period. and recording command REC
stops, and the reproduction/recording switching circuit 24 returns to the raw side (41).

The recording check process described above is performed in the next cycle.

After this, the main controller 30 further starts an operation of moving the magnetic head 21 to the next unrecorded track for the next photographing.

When the main controller 30 notifies the exposure control device 40 that the recording check process has been completed, the drive device 42 moves the mirror 45 down on the exposure control device 40 side, and prepares for the next shutter opening/closing. drive unit 41 for
The charging operation of the spring of the shutter 46 is started by operating the shutter drive motor.

When the charging of the spring and the transfer of the magnetic head 21 to the next track are completed, the photographing and recording process for one frame is completed.

As can be seen from FIG. 2, the shutter 46.
Mirror 45. No movement of the diaphragm 44 is taking place. Therefore, the occurrence of mechanical vibrations caused by these operations, fluctuations in power supply voltage caused by driving the drive devices 41 and 42 including the shutter drive motor and the aperture drive motor, and the occurrence of noise are prevented, and video signal recording and recording checking are prevented. Since the environment is maintained in a suitable environment, these malfunctions are less likely to occur.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the electrical configuration of a still video camera, and FIG. 2 is a time chart showing its operation. 11...Magnetic disk, 21...Magnetic head. 30... Main control device, 40... Exposure control device. 41... Aperture drive device. 42...Mirror, shutter drive device. 44...Aperture, 45...Mirror, 4G...Shutter. that's all

Claims (5)

[Claims] (1) In a still video camera in which a still video signal from an imaging device is recorded on a rotating magnetic disk by a magnetic head, at least during the recording period of the still video signal on the magnetic disk by the magnetic head, at least A still video camera characterized by comprising a control means for prohibiting driving of an electromechanical drive device of an exposure system including a shutter drive device. (2) The still camera according to claim (1), wherein the electromechanical drive device of the exposure system includes an aperture drive device.
Video camera. (3) The still video camera according to claim (1), wherein the electromechanical drive device of the exposure system includes a mirror drive device. (4) The still video camera according to claim (1), wherein the electromechanical drive device of the exposure system includes an autofocus drive device. (5) The control means prohibits driving of the electromechanical drive device of the exposure system even during a recording check processing period performed after recording processing of still video signals. Still video cameras listed in ).