JPS60165875A - Electronic still camera - Google Patents

Abstract

PURPOSE:To attain still image pickup and its recording without losing a shutter chance by constituting the camera that a picture to an image pickup element is fetched when the 2nd release is operated before a magnetic disc reaches a recordable state and the picture signal from the image pickup element is read and the recording to the magnetic disc is started after the magnetic disc reaches the recordable state. CONSTITUTION:When the 2nd release is operated before the magnetic disc 13 reaches a recordable constant speed and a specified phase, the inhibiting state of picture read is continued. When the magnetic disc 13 is transited to the recordable state, one frame's share of picture signal is read from an image sensor 5, and a modulation video signal corresponding to the picture signal is outputted from a signal recording circuit 9 at the same time and recorded on the magnetic disc 13 via a recording amplifier 11 and a recording head 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to purely electronic still photography of a subject by focusing an image of the subject on an image sensor, which is a photoelectric conversion device, through an optical system. The device is installed in an electronic digital camera configured to record still image signals read from a rotating magnetic disk on a rotating magnetic disk.

Conventional technology and problems This type of electronic still camera generally has a built-in battery, but in order to save power, the circuits are not energized except when shooting, and the magnetic deosc drive device is not activated. .

When shooting, for example, by closing the power switch linked to the release button with a preliminary release operation,
Power is supplied to each circuit block of the camera's EE system and recording system, and the magnetic disk begins to rotate accordingly.

However, until the magnetic disk reaches a constant speed of about 1,000 rpm, preferably reaches a specified rotational phase state and is locked (that is, until the magnetic disk reaches a recordable state), Unable to record images. If this recording standby time is shorter than the total time of the aperture closing time after the release operation and the exposure opening/closing time of the shutter, there will be no restrictions on the photographer, but in order to achieve this, it is necessary to incorporate a high-torque motor. This requires an increase in the instantaneous current (starting current), etc., which contradicts the demands of this type of camera for compactness, size, and power saving.Therefore, the above-mentioned recording standby time is generally 100 milliseconds. I need some degree.

For this reason, the photographer turns on the power switch linked to the release button, looks at the indicator that displays the status of the rotating disc, confirms that it is ready for recording, and then presses the release button again. It means pushing.

During normal shooting, it takes several hundred milliseconds to several seconds for operations such as focus adjustment, exposure adjustment, and composition determination, so it is necessary to be aware of the recording standby time of magnetic disks as described above. do not have. However, when shooting a moving or changing object, for example, the preliminary movement of shirt release (hereinafter referred to as the 2nd release movement) and the main movement of shirt release (hereinafter referred to as the 2nd release movement) This can occur in a short period of several tens of milliseconds. In this way, if the release button is pressed before the magnetic disk is in a suitable state for recording, this second release operation is usually ignored and, for example, a warning sound is used to warn the photographer of the erroneous operation. ing. However, ignoring the second release operation and not starting to capture still images into the photographing element means that the shooting timing (
There were major problems like missing Shaq Chance.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems.The purpose of the present invention is to prevent the shutter opportunity from being missed even when the shutter button is pressed halfway, where the time from the first Lullize operation to the second release operation is relatively short. To provide an electronic still camera capable of still photography and recording without having to do so.

Structure of the Invention The above-mentioned object is to provide a two-step release button that records an image by a first Lullies operation and a second release operation, and to turn on the power and start the motor in accordance with the first Lullies operation to record a magnetic disk. At the same time as rotation starts, electricity is applied to each circuit system, and then after the magnetic disk reaches a recordable state, when the $22 release operation is performed, the image signal is read out from the first imager immediately after the shutter operation, and the magnetic When recording is performed on a disk, and the second release operation is performed after the magnetic disk starts rotating but before the magnetic disk reaches a recordable state, the signal is only captured by the shutter operation to capture the image into the image sensor. This is accomplished by an electronic still camera that is configured to wait with readout prohibited, and then, when the magnetic disk reaches a recordable state, to begin receiving image signals from the image sensor and recording onto the magnetic disk.

Embodiment of the Invention FIG. 1 is a block diagram showing an embodiment of the invention.

Incident light from a subject (not shown) is transmitted through a front lens 1, an iris (aperture) 2, and a rear lens 3 arranged on the same optical axis.
and an optical system such as a shutter 4, the image sensor 5
image is formed. As the image sensor 5, a solid-state image sensor using MOS, CPD, or COD, or an image sensor such as an image sensor is used, and among these, an image sensor with a relatively long charge retention time is preferable, and the aperture value of the iris 2 is determined. The amount of light received by the photometer 6 is sent to an exposure control circuit 7, and the opening/closing operation of the shutter 4 is controlled by the exposure control circuit 7.

The image sensor 5 is controlled by an image sensor drive circuit 8. The still image signal for one frame converted into an electrical signal by the image sensor 5 is sent to the signal recording circuit 9, where it is modulated ( For example, FM modulation). The operation of this circuit 9 is controlled by a reference signal generating circuit 10 and a recording timing control signal to be described later. The modulated video signal output from the signal recording circuit 9 is sent to the recording amplifier 11.
However, at this point, the magnetic disk 13 driven by the DC motor 14 must be at a predetermined steady speed at which writing can be performed and has not reached a specified rotational phase. No.

As the DC motor 14 starts, the frequency generator 15
A frequency signal corresponding to the rotational speed of the motor 14 is outputted from the servo circuit 16 and taken into the servo circuit 16.

The servo circuit 16 performs speed control using the frequency signal, and at the same time compares a reference signal vP, which will be described later, with a phase detection signal PG, and performs phase control on the DC motor 14 to rotate the magnetic disk 13 at a predetermined constant speed. to lock to the specified rotational phase. A bin amplifier coil 18 electromagnetically detects a PG (phase generator) pin (not shown) installed at a predetermined position on the rotating magnetic disk 13. The detection signal is amplified by a PC amplifier 18,
It is supplied to the servo circuit 16 and the like as a phase detection signal PG.

When the release button 20 is pressed for the first time, which is the first release operation, the release lever integrated with the release button 20 enters shallowly and closes the power switch, supplying power to each circuit block (the power supply circuit to each circuit block is (not shown), and further sets the signal S1 to H (high) level. Further, when the release button 20 is pressed next, which is the second release operation, the release lever is moved deeply to close the shirt release switch and set the signal S2 to the H level. The signal S1, which has become H level due to the Luries operation, is sent to the servo circuit 18, and the circuit 18 drives the DC motor 14.
Start. Next, the signal S2, which has become H level due to the second release operation, is sent to the exposure control circuit 7, which opens and closes the shutter 4.

Further, a circuit 21 shown surrounded by a chain line is a servo determination circuit that determines whether or not the rotation of the magnetic disk 13 has reached a servo target value of a specified rotational phase at a predetermined speed, and includes a pair of monostable vibrators (hereinafter referred to as (referred to as mono-multi)22
and 23.4 R-S type flip-flops (hereinafter referred to as
(referred to as FF) 24 to 27, AND gates 28 and 1
It has a monomulti 28 that can be operated individually and triggered.

The two monomultis 22 and 23 are connected in series to form a phase determination circuit, and the four FFs 24 to 27 are connected in cascade to form a 4-bit shift register.

The reference signal VP output from the reference signal generation circuit 10 is input as a trigger signal to the trigger input terminal A of the monomulti 22, and its Q terminal output pulse SQL falls. This output pulse SO1 rises according to a predetermined time constant, is input to the trigger input terminal A of the next monomulti 23, and output pulse SO2 of its Q terminal rises.

The signal PC output from the PG amplifier 19 is input as a clock pulse to each clock terminal CP of the FFs 24 to 27 constituting the shift register, and the signal SO4 output from the output terminal Q of the monomulti 29 is input to each reset terminal R thereof.
is input as a reset pulse, and their set terminals S are respectively grounded. Furthermore, the phase determination signal SO2 outputted from the output terminal Q of the monomulti 23 constituting the phase determination circuit is inputted to the data input terminal of the first stage FF 24, and also inputted to one input terminal of the AND gate 28. .

The AND gate 28 takes the AND of the signal 502 and the signal PC, and sends the result to the trigger input terminal A of the monomulti 29.7 Therefore, when the input terminal of the first FF 24 is at H level, the clock is turned off. When a pulse enters the terminal CP4, its output terminal Q becomes H level. When a clock pulse enters the terminal CP while the input terminal of the next-stage FF 25 is at the H level, its output terminal Q becomes the H level. In this way, if the input terminal of the first FF24 is at H level, this data is sequentially sent to the last FF27 by four clock pulses, and if the reset signal SO4 is not generated during that time, the data is sent to the last FF27. H level signal SO from terminal Q of
5 is output. On the other hand, if the signal PG, which is a clock pulse, is not input when the terminal of the first FF 24 is at H level (if it does not become H level), the AND gate 28
The output remains at L (low) level, and the mono multi 2
The glue/trigger operation of 9 is not performed, so the output terminal Q of the monomulti 28 changes to H level, and all of the FFs 24 to 27 are reset. Therefore, no H level signal is output from the output terminal Q of the last FF 27.

Hereafter, FF25. FF28. FF2? If the signal PG is not input when the input terminals of FF become H level one after another, all FFs 24 to 27 are reset.
The last FF2? An H level signal is not output from output terminal Q of. That is, unless a synchronized state in which the phase detection signal PC goes to the H level during the period in which the phase determination signal SO2 is at the H level occurs at least four times in a row, the output signal SO5 of the servo determination circuit 21 is recorded on the magnetic disk 13. It does not become H level indicating that the possible state has been reached.

Further, a circuit 30 surrounded by a chain line is a read and write timing control circuit, and an AND gate 31,
A pair of R-5 flip-flops (FF) 32 and 3
3 and an AND gate 34.

The AND gate 31 receives the judgment output signal 505 of the servo judgment circuit 21 and the detection signal PG output from the PC amplifier 18.
and the exposure completion signal (exposure completion signal) S11 supplied from the exposure control circuit 7, and the result is inputted to the clock terminals CP of both FFs 32 and 33 as a clock signal. The input terminal of the front-stage FF32 is connected to a constant voltage Vcc power supply, and its output terminal Q is connected to the rear-stage FF32.
The set terminal S of each of the FFs 32 and 33 is connected to a power supply reset circuit 40 that instantaneously changes to an H level and returns to an L level when the power is turned on. Further, the exposure start signal S1 output from the exposure control circuit 12 is connected to the reset terminals R of the FFs 32 and 33.
Supply 2. This exposure start signal S12 becomes H level in synchronization with the start of the front curtain operation (start of exposure) of the shutter 4.

The AND gate 34 receives the image sensor read command signal So? output from the terminal Q of the FF 32 in the previous stage. and the record sheet 1 instruction signal S output from the terminal Q of the FF33 in the subsequent stage.
A logical AND operation is performed with O8, and the result is sent to the signal recording circuit 9 as a recording timing control signal SO8. Further, the above-mentioned read command signal S07 is transmitted to the image sensor drive circuit 8.
The image signal captured by the image sensor 5 is read out via this circuit 8.

An example of the operation of the electronic still camera configured as described above will be described with reference to timing charts shown in FIGS. 2 and 3.

FIG. 2 shows a case where a second reset operation is performed after the magnetic disk 13 reaches a recordable state. First, when the power switch is closed in response to the photographer's first press operation (first release operation) of the release button 20, power is supplied to each component circuit and the signal Sl becomes H level. As a result, the DC motor 14 is
is activated, and the phase detection signal P amplified by the PG amplifier 18
G, 'X quasi-signal v output from the reference signal generation circuit lO
P and the rotational speed signal output from the frequency generator 15 are input to the servo circuit 16. The servo circuit 16 controls the phase of the DC motor 14 in response to these signals so that the magnetic disk 13 reaches a specified rotational phase at a predetermined constant speed.
When the target value is reached, the state is locked.

On the other hand, the two monomultis 22 and 23 forming the phase determination circuit produce a pulsed phase determination signal SO2 that is shifted by a prescribed phase with respect to the reference signal vP. Therefore, after the magnetic disk 13 reaches the specified phase at a constant speed at which recording can be started, the phase detection signal PG is generated at equal intervals in synchronization with the phase determination signal SO2 having a specified pulse width. Therefore, once the recordable state is reached, the output SO3 of the AND gate 28 becomes the signal P.
Since it occurs in coincidence with G and triggers the monomulti 28, the reset signal SO4 output from the terminal Q is always at L level, and if this state continues four or more times, the servo judgment circuit outputs it from the terminal Q of the FF 27. 21 output signal S05
is always at H level.

The second press of the release button 20 by the photographer (
When the second release operation) is performed, 1. - The switch switch closes and the signal S2 becomes H level. Exposure control circuit 7
In response to the rise of this switch signal S2, the iris 2 is driven until the aperture value is set/set in advance. Upon completion of this aperture operation, the exposure control circuit 7 opens and closes the shutter 4. At the same time, the exposure control circuit 7 sets the exposure start signal S12 to H level in synchronization with the start of the front curtain operation of the shutter 4.

Next, in synchronization with the completion of the rear curtain operation of the shutter 4, the exposure completion signal Sll is set to H level.

After the power is turned on and before the shutter 4 operates, the exposure completion signal Sll is at the L level, so at that time, the output of the AND gate 31 is Output signal S
O6 is at L level. Therefore, Q terminal output signal SO? of FF32 which accepts the signal S06 as a clock?
The Q terminal output signal 5oft of the FF 33 is maintained at H level and L level by the power supply reset circuit 40 connected to each S terminal, and the image sensor 5
is read out, but the signal recording circuit 9 is not driven.

Next, when the exposure start signal S12 becomes H level, FF3
2 and FF33 are reset, and their respective Q terminal outputs SO? And the Q terminal output S08 changes to L level and H level. Therefore, during this period, reading from the image sensor 5 is prohibited, image signals are stored, and since the output signal SO8 of the AND gate 34 is not output, the signal recording circuit 9 is also not driven.

After that, when the exposure completion signal Sll becomes H level, since the output signal SO5 of the servo determination circuit 21 is always maintained at H level, a pulse signal synchronized with the phase detection signal PG is sent from the AND gate 31. SOB is generated as a clock signal. This pulse signal S06 is input to the CP terminals of FF32 and FF33. The first pulse of this pulse signal S06 is the CP of FF32 and FF33.
When input to the terminal, the Q terminal output SO7 of FF32 becomes H.
The image signal stored in the image sensor 5 is read out, and the Q terminal output S09 of the FF 33 is maintained at the H level, so the recording timing control signal SO8 becomes the H level via the AND gate 34. , the signal recording circuit 9 is driven, and recording is performed on the magnetic disk 13 via the amplifier 11 and recording head 12.

After that, the second pulse of this pulse signal SO8 becomes F.
When input to the CP terminal of F32 and FF33, the FF
While the Q terminal output SO7 of the FF 32 is maintained at the H level, the Q terminal output SO8 of the FF 33 changes to the L level, the output SO8 of the AND gate 34 becomes the L level, and the drive of the signal recording circuit 9 is stopped and recording is started. finish.

As mentioned above, the AND gate 34 outputs each of the above-mentioned output signals SO.
7 and 809, and outputs the result to the signal recording circuit 9 as a recording timing control signal S08. Therefore, the control signal SO8 is the output signal So? 7) It becomes H level in synchronization with the rising edge, and becomes L level in synchronization with the falling edge of the output signal SO9. At the same time, the signal SO7 is supplied to the image sensor drive circuit 8 as an image sensor read command signal, and the readout of the image sensor 5 is prohibited and readout is controlled via the drive circuit 8. That is, the period T11 when the image sensor read command signal SO7 is at the L level is an image sensor read prohibition period that prohibits the reading of the image signal captured by the image sensor 5, and the period TM when the recording timing control signal SO8 is at the H level is This is the image signal recording period.

In this way, when the magnetic disk 13 is started by the second release operation of the release button 2o and the second release operation is performed after the magnetic disk 13 is locked to a specified phase at a predetermined constant speed at which recording is possible, the second release operation is performed. As shown in FIG. 2, in synchronization with the start of exposure of the shutter 4, the read command signal S07 of the image sensor goes to L level indicating that reading of the image sensor 5 is prohibited, and the black signal immediately after the completion of exposure of the shutter 4 becomes L level. In synchronization with the first pulse of the link signal SOB, the image sensor read command signal SO7 is set to H level to cancel the image sensor reading prohibition, and at the same time, the recording timing control signal SO8 is set to the H level to permit recording. Therefore, when the second release operation is performed when recording is possible, image reading from the image sensor 5 is prohibited until the opening/closing operation of the shutter 4 is completed. An image signal for one frame is read out from the image sensor 5 in synchronization with the phase detection signal PC,
At the same time, the modulated video signal from the signal recording circuit 9 is sent to the recording head 12 via the recording amplifier 11 and recorded on the magnetic disk 13.

In this way, after signals are read from the image sensor 5 and recorded on the magnetic disk 13, the exposure completion signal Sll is set to L level, for example, after a predetermined period of time or by charging the next shirt release. , by turning off the pulse signal SO6, the state of each circuit can be returned to the initial state for the next photographing.

FIG. 3 shows a case where the second release operation is performed before the magnetic disk 13 reaches the recordable state. As shown in FIG. 3, the magnetic disk 1
3 starts rotating by the DC motor 14, but until it is locked to the specified phase of constant speed, the phase detection signal PC is generated once per rotation of the motor 14, but the generation period is different from the phase determination signal SO2. This judgment signal SO2
occurs randomly. Therefore, there is a possibility that the signal PG is generated by chance at a certain rotational phase, that is, when the signal SO2 is at H level; The signal PC is not necessarily generated during the next phase. In this way, it would be an incorrect judgment to assume that the phase of the signal SO2 and the signal PC coincidentally coincided with each other as the specified phase of constant speed has been reached.
The servo determination circuit 21 determines when the rotation of the magnetic disk 13 reaches a specified phase at a constant speed when the signal PC is generated in synchronization with the signal SO2 at least four times in a row.

That is, when the pulse of the signal PG happens to fall within the H level of the signal SO2, the output SO3 of the AND gate 28
becomes a trigger pulse and brings the Q terminal output signal SO4 of the monomulti 28 to the L level, but if the pulse of the signal PC does not occur when the signal SO2 is at the H level next, the output signal SO4 is determined by a time constant. After a predetermined time, it becomes H level and resets all FFs 24 to 27 of the shift register. -For this reason, FF2? Servo judgment circuit 2 coming from
The output signal SO5 of 1 becomes H level only after the generation of the signal PC is synchronized with the pulse of the signal SO' four times in succession.

On the other hand, even in the case of a quick press in which the second release operation is performed immediately following the first release operation, the operation of the exposure control circuit 7 is the same as in the case of FIG. 2. That is, in response to the second release operation, the signal S2 becomes H level, the iris 2 performs the aperture operation, the shutter 4 is opened and closed, and the image of the subject is captured into the image sensor 5 via the optical system, and the shutter 4 The exposure start signal S12 is synchronized with the exposure start operation of
becomes H level, thereby setting the image sensor readout command signal SO7 to L level indicating that reading of the image sensor 5 is prohibited, and then setting the exposure completion signal Sll to H level in synchronization with the exposure completion operation of the shutter 4. An action is taken.

However, in this case, since the second release operation is performed before the rotation of the magnetic disk 13 reaches the specified phase at a recordable constant speed, even if the exposure completion signal Sll reaches the H level, the servo determination circuit 21 Since the output signal (recordable determination signal) S05 is at the L level, the clock signal 806 is not generated from the AND gate 31 to the FFs 32 and 33. Therefore, the image sensor read command signal So? remains at the L level regardless of the rise of the signal Sll described above, and the image reading prohibition state continues. For this reason, the recording timing control signal 508 output from the AND gate 34 to which the signal SO7 is input also goes low.
maintained at the same level.

Thereafter, when the magnetic disk 13 enters the recordable state, the output signal SO5 of the servo determination circuit 21 changes to H level as described above, and the clock pulse SO8 is generated from the AND gate 31, and the first clock pulse SO8 of the clock pulse SO8 is generated. In synchronization with the pulse, the read command signal S07 of the image sensor becomes H level, the prohibition of image reading is canceled, and at the same time, the recording timing control signal SO8 becomes H level. Next, in synchronization with the second pulse of the clock pulse 806, the signal 'V1 signal SO9 goes low, and the signal 808 goes low. In this way, the output timing of the recording timing control signal SO9 is adjusted to the readout command signal SO7 of the image sensor.
I am trying to synchronize it with the l field, so
When the magnetic disk 13 reaches a recordable state, an image signal for one frame is read out from the image sensor 5, and at the same time, a modulated video signal corresponding to the image signal is output from the signal recording circuit 9, and is sent to the recording amplifier 11 and recording. head 1
2 is recorded on the magnetic disk 13.

Furthermore, as shown in FIGS. 2 and 3, since reading from the image sensor is performed until immediately after the shutter 4 is opened and the optical signal is taken into the image sensor 5, the image generated before the shutter release is read out. It is possible to sweep out the dark current of the sensor 5 and capture only necessary optical signals into the image sensor 5.

Note that the servo determination circuit, timing control circuit, etc. can be advantageously replaced by a system controller using a microprocessor. In addition, in the embodiments described above, a focal plane type shutter will be explained.7. However,
Any shutter such as a lens shutter or an electronic shutter can be used as this shutter.

Effects of the Invention As mentioned above, the electronic still camera of the present invention has the first effect.
When a second release operation is performed after the first release operation turns on the power to each circuit system and starts rotating the magnetic disk, and the magnetic disk reaches a recordable state with a specified rotational phase at a steady rotational speed, the second release operation is performed. The shutter operation is performed by the second release operation, and after the shutter operation, photoelectric conversion from the photographing element and recording on the magnetic disk are started immediately, and before the magnetic disk reaches the above-mentioned recordable state, the second shutter operation is performed. When the second release operation is performed, the shutter operation is performed with the second release operation, and photoelectric conversion and recording are started only after the magnetic disk reaches the above-mentioned recordable state, so there is no chance of missing a shutter opportunity. This has the advantage that good still photography and recording can be carried out appropriately without having to do so.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the configuration of an embodiment of the present invention, and FIGS. 2 and 3 are timing charts for explaining the operation of the embodiment shown in FIG. 1.3...Lens, 2...Iris (aperture), 4...Shutter, 5...Image sensor (imaging device), 6...Photometering section, 7...Exposure control circuit, 8 ... Image sensor drive circuit, 9 ... Signal recording circuit, 10 ... Reference signal generation circuit, 11 ... Recording amplifier, 12 ... Recording head, 13 ... Magnetic disk, 14 ... DC motor, 15... Frequency generator, 16... Servo circuit, 18... Pick-up coil, 18... PG amplifier, 20... Release button, 21... Servo determination circuit, 22.23 .29... Monostable multivibrator (mono multi), 24.25, 28.2? , 32.33... Flip-flop (FF), 28.31.34... AND gate, 30... Timing control circuit, 40... Power supply reset circuit.

Claims (1)

[Scope of Claim] An electronic still camera equipped with an image sensor that photoelectrically converts a methyl image for one frame, and a magnetic disk that records the photoelectrically converted methyl image at a constant rotation speed, a two-stage release button that instructs to record an image of a subject by a second release operation and a second release operation; a disk motor starting means for starting a motor that rotates the magnetic disk in response to the first release operation; a servo control means for controlling the magnetic disk to a recordable state at the steady rotational speed via a servo control means for controlling the magnetic disk to a recordable state at the steady rotational speed; and a means for outputting a signal indicating that the magnetic disk, which has started rotating by the first Lullize operation, has reached the recordable state. , an exposure control means for capturing a still image into the image pickup device by opening and closing a shutter in response to the second release operation, and a notification indicating that the operation of the shutter is completed and the magnetic disk has reached the recordable state. and timing control means for controlling readout start timing of the image sensor and recording start timing of the methyl image on the magnetic disk according to the signal, and the magnetic disk starts rotating in response to the Lullize operation. When the second release operation is performed before the shutter reaches the recordable state, reading of the image pickup device and reading of the magnetic disk are performed after the shutter operation is completed and the magnetic disk drive reaches the recordable state. An electronic still camera configured to start recording.