JPS6285583A - Electronic still camera - Google Patents

Abstract

PURPOSE:To attain a synthetic picture obtained by multiplex exposure and special reproduction in a consecutive shooting mode, by reading alternately odd and even fields of stored video signals in response to plural shutter releases. CONSTITUTION:When a shutter button 22 is pushed, a control circuit 20 releases a shutter 14 for photographing. A signal generating circuit 18 produces a signal to read out alternately the odd and even fields of the video signals in synchronizing with a phase pulse PG received first after the shutter 14 is closed. Then an image pickup element 26 is driven for output of the stored charge. A control circuit 20 gives an instruction to a processing circuit 34 to record the video signals on a disk 42 based on the timing of a deciding circuit 19 after the shutter 14 is closed. Thus the stored charge of the element 26 is read out and recorded successively on the prescribed track of the disk 42.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention captures an image of a subject with an electronic still camera, more specifically, an imaging device such as a solid-state image sensor, and transfers the obtained video signal to a magnetic disk or other device. This invention relates to an electronic still camera that performs field recording on a rotating recording medium.

(Conventional technology #) Conventionally, on the screen of a television receiver, one odd field and even field are bare to form one frame, and two-to-one interlacing is performed to construct a complete frame still image. is well known.

Therefore, even in electronic still camera systems in which the reproduction of images captured by the electronic still camera is controlled by a separate television receiver, some cameras are capable of field recording and frame recording.

Among these, in electronic still cameras capable of field recording, image information of a subject imaged by one shirt release is field-recorded, for example, on one track of a rotating magnetic disk, and is reproduced through field-frame conversion.

Now, one special use of this field-recording electronic still camera is to create a composite image using multiple exposures, which could be done with a conventional silver halide film camera. Field record the video information of these two tracks to 2
This can be achieved by simultaneous reproduction (frame reproduction) from the channel reproduction magnetic head C2.

(Problems to be Solved by the Invention) However, in conventional field recordable electronic still cameras, the recorded information recorded on each track of the magnetic disk is divided into odd or even fields due to multiple timings at the time of shirt release. Because any signal is recorded irregularly, for example, even if you try to form a composite image by overlapping the video information of the 1st track and the fa2 track, the odd and even fields will not always be paired. Therefore, frame playback cannot be performed.

Also, when using a camera like this to take continuous pictures.

As mentioned above, there is no periodicity of a single signal (odd and even fields are repeated alternately) between continuously shot video information, so each video is frozen and played back like an exploded photograph. I couldn't get a picture.

SUMMARY OF THE INVENTION An object of the present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to manage individual video information sequentially recorded on each track by alternately repeating odd and even fields.

To provide an electronic still camera capable of field recording, which enables composite images by multiple exposure and special playback during continuous shooting.

(Means for Solving the Problems) That is, the above object of the present invention is to solve I! an optical shutter that responds to a light instruction; an imaging means that images a subject by opening the optical shutter and stores a video signal corresponding to the subject image; and a recording control means and recording that field records the video signal on a rotating recording medium. and managed so that odd fields and even fields of each video signal stored in the imaging means corresponding to a plurality of shirt releases are read out alternately. Achieved with a still camera.

(Example) Next, a practical example of an electronic still camera according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, an electronic still camera according to an embodiment of the present invention includes a photographing lens system 10 for forming an image of a subject. An imaging optical system 24 including an aperture 12 and an optical shutter 14 is closed. This imaging optical system 24 is connected to the control circuit 20,
Regarding exposure control, this control circuit 20 uses a photometric element 16 disposed in its optical path and a shirt release button 22.
This is a control circuit that controls the shutter 14 and the aperture 12 in response to the switch SW2 and the synchronization signal generation circuit 18.

In this example, the shirt release button 22 performs a two-stage stroke operation, and in the first stroke, the switch SW1 is closed, the circuit system N source 76 responds, and the IE source is supplied to each part of the apparatus. Due to this, a servo circuit 50, which will be described later, starts a drive motor 44 for a magnetic disk 42 as a rotating recording medium.

Further, in the next step of the button 22, the control circuit 20 operates to perform photographing and recording. This configuration avoids wasting power from a power source such as a battery.

At the focal plane of the optical system 24, a solid-state image sensor +26 having a two-dimensional image sensor array, such as a COD, is arranged,
This generates a video image corresponding to the subject image formed on the image carrier plane 28 in response to a drive signal including a vertical synchronization signal and a horizontal synchronization signal sent from the synchronization signal generation circuit 18 through the control line 30. The signal is accumulated and output as a serial signal to the output 32.

The output 32 of the image sensor 26 is connected to a recording signal processing circuit 34, which processes a drive signal including a vertical synchronization signal and a horizontal synchronization signal sent from the synchronization signal generation circuit 18 through a control line 36, and a phase pulse PG to be described later. C: Frequency-modulates the video signal output from the solid-state image sensor 26 by rask scanning in response to a recording instruction signal sent from the control circuit 20 through the control line 35, and generates a modulated video signal in a predetermined format. This circuit outputs the signal to the output 37 as a signal. This output 37 is connected to a switch 43 and a recording amplifier 38.
．． 39 to magnetic recording heads 40, 41.

Are the magnetic recording heads 40 and 41 mutually? = A two-channel head structure located on two adjacent tracks, which are integrally carried by a head transport mechanism conceptually indicated by a dotted line 92, and are each transported onto a predetermined track of the magnetic disk 42 by a head transport circuit 90. This is a magnetic transducer element that records video signals on. Head transfer circuit 90 is controlled by control circuit 20.

If the video signal to be recorded is an odd field, the switch 43 selects 1, for example, an odd number field (1.1 field) of the magnetic disk 42.
g3, 5th. ...), and if it is an even field, the magnetic head 4111 is located on an even numbered track (2nd, 4th, 6th, etc.). It is controlled by the control circuit 20 as follows. @ㅅThe disk 42 has a core 48, and the core 48 is detachably mounted on a rotating shaft 46 driven by a spin motor 44, and is rotated in a predetermined direction by the motor 44, a frequency generator CFG) 54, and a servo circuit 50. Steady rotation.

The magnetic disk 42 has a track pitch of about 100 μm on a small magnetic recording sheet, for example, about 47W in diameter.
That is, a track width of about 50 to 60 μm is recorded with a single band width of about 50 to 40 μm. The motor 44 rotates the magnetic disk 42 at a rate of 3 per minute.
, 600 rotations at a constant speed N, thereby making it possible to record the image signal at field speed.

The core 48 is provided with a phase generator 52 for generating one phase pulse PG at a predetermined reference rotational phase (angle) per one rotation of the disk 42 . A detection coil 56 is disposed in the vicinity of the core 48 - this is a detector which outputs a phase pulse PG on a signal line 58 when the phase generator 52 passes in the vicinity of the coil 56 . This signal line 58
is connected to one input of the control circuit 20, the signal processing circuit 34, and the AND gate 60.

The servo circuit 50 supplies a drive current for the motor 44 to a connection line 62 and generates a signal according to a frequency signal FG generated by a frequency generator 54 on a signal line 64 and a reference clock CLKI received from a reference generation circuit 68 on a signal line 66. This is a motor control circuit having a phase M period loop (PLL) that controls the rotational speed and rotational phase of the motor 44. As the PLL control circuit, a motor control integrated circuit such as Toshiba Model TC9142P is used.

In this embodiment, the frequency generator 54 sets the repetition frequency of the signal FG to an integer fraction of the frequency of the color subcarrier of the video signal.
is sufficiently higher than that of the 1-phase pulse PG, e.g. 2
It is set to take a value about 0 times higher.

The reference generation circuit 68 has a crystal oscillation element 70 that generates a clock with a stable frequency, and steps this down to 14.4.
MHz reference clock CLK2.

Further, a circuit divides this frequency and generates CLKI of a frequency (3.58 MHz) corresponding to the color subcarrier at output cuffs 2 and 66, respectively.

The servo circuit 50 has a lock detection circuit 100, and one lock detection circuit 100 counts the period or frequency of the frequency signal FG, and the motor 44 adjusts the rotation speed N to a predetermined value. This is a circuit that detects whether or not it is maintained within an acceptable range, that is, in a "locked" state.

When the lock detection circuit 100 enters the "lock" state, its output cuff 4 becomes high level and outputs the lock detection signal 75.

The output cuff 4 of the lock detection circuit 100 is connected to a monostable circuit (MM) 80 through a set force S of a prep frog 76 and an inverter 78. The latter output 82 is connected to an audible signal generator 84, such as a piezoelectric element, and when the output cuff 4 of the lock detection circuit 100 goes from a high level to a low level, the generator 84 is energized for a predetermined period of time, and from now on an audible alarm is generated. However, instead of or in addition to an audible alarm, a visual indicator may be used that outputs a visual indication.

On the other hand, this lock signal 75 is also supplied to the control circuit 20 via the control line 91.

The Q output 85 of the flip-flop 76 is connected to the AND gate 60.
The output 86 of the latter is connected to the reset input R of the flip-flop 76 and to the synchronization signal generation circuit 18.
connected to the reset input of the As can be seen from this configuration, when the output cuff 4 of the lock detection circuit 100 becomes high level, that is, when the lock detection signal 75 is output,
Flip-flop 76 is set and AND gate 60
One input 85 of is energized. Therefore, after that, the phase pulse PG first detected by the coil 52 passes through the gate 60 and is input as a reset pulse 88 to the synchronization signal generation circuit 18, so that the circuit 18 is reset.

The synchronization signal generation circuit 18 freely generates various cyclic control signals from the reference clock CLK2 of the clock input cuff 2.
This circuit outputs them to outputs 30 and 36. For example, the output 30 outputs a sensor drive signal including a 15.7 KHz pixel clock, a synchronization signal, etc., which drives each image sensor cell of the image sensor 26 to output accumulated charge. Furthermore.

The output 30 is connected to a judgment circuit 19, which judges the timing (odd field or even field) of the video signal to be read out and sends it to the control circuit 20.
control. The output 36 also includes a recording signal processing circuit 34.
Synchronization signals such as a recording spinal cord signal for controlling the recording and a 60H, z vertical synchronization signal and horizontal synchronization signal are output.

The synchronization signal generation circuit 18 is reset to an initial state by a reset pulse 88. therefore.

Once the reset point is determined, various control signals can be output at a predetermined period with the determined phase. I will explain about shooting.

As an initial photographing operation, when the release button 22 is operated and the switch SWI is closed to turn on power to each circuit of the apparatus, the motor 44 starts rotating.

The synchronization signal generation circuit 18 generates a drive signal to drive the image sensor 26.
discharge the residual charge. When the rotation of the motor 44 stabilizes after a predetermined period of time has elapsed, the synchronization signal generation circuit 18 generates a reset pulse 88 based on the lock signal 75 and the phase pulse PC output from the lock detection circuit 100.
The camera is reset and set to ready for shooting. Under such a state, when the release button 22 is pressed to enter the second step, the control circuit 20 opens the shutter 14 in response to this, and imaging of the subject is executed for the first time. Note that the open period of the shutter 14 depends on the illuminance of the incident light detected by the photometric element 16.

The synchronization signal generation circuit 18 generates a drive signal for alternately reading out the video signal connection timing, that is, the odd field and the even field, in synchronization with the phase pulse PG that arrives first after the shutter 14 is closed, and uses this signal to perform imaging. The element 26 is driven to output the accumulated charge.

Further, the 1 determination circuit 19 detects the timing (odd field, even field) of the video signal based on the 1 drive signal, and transmits it to the control circuit 20.

- After the shutter is closed, the force control circuit 20 controls the recording signal processing circuit 34 to output the video signal to the disc at the timing of the desired feel F based on the signal from the first determination circuit 19 and by the first arriving signal PG. 42. Due to this, the charge accumulated in the image sensor 26 is read out, and this is read out by the recording signal processing circuit 34.
The signals are sequentially recorded on predetermined tracks of the magnetic disk 42 via the switch 43 and amplifiers 38 and 39.

In this practical example, video signals of odd fields are set to be recorded on odd-numbered tracks of the magnetic disk, and video signals of even-numbered fields are recorded on even-numbered tracks. Based on this, the switch 43 switches, and a predetermined magnetic head is set. That is, the video signal of, for example, an odd field obtained by the first shirt release described above is switched to be recorded on the first track of the FiB disc. Next, when another object is imaged by the same steps M as described above, this video signal is read out as an even field by the drive signal and recorded on the second track.

1st. When the recording of the second track is completed, the control circuit 20
controls the head transfer circuit 90 to move the head 40.4.
1 as the next track position, 3rd. The video signal of the odd field is transferred to the fourth track and the video signal of the odd field is transferred to the third track according to the first imaging.
track - the next even field video signal is the fourth
so that they are recorded sequentially on the track.

Once a recorded magnetic disk on which video signals of odd and even fields are recorded alternately in this manner is provided, this recorded magnetic disk is loaded into a reproducing apparatus. The playback device uses a frame playback device with a two-channel magnetic head structure, which plays back both the video signal of the odd field on the first track of the magnetic disk and the video signal of the even field of the second track, and transmits it to the television receiver. A composite image of these feels F is reproduced as a frame.

In addition, when using the electronic still camera of the present invention in continuous shooting mode, the continuous shooting mode is generally used for decomposition photography in which individual images are frozen once, for example, to study golf or tennis swings. There is a strong correlation between the pictures. Therefore, as shown in FIG.
# n + 1 * n + 2) A picture in which odd and even fields are recorded alternately is one field.
In frame-converted field playback, the playback is as shown in Figure 2a.On the other hand, in frame playback, two adjacent tracks are played back at the same time, resulting in an exploded photo-like image as shown in Figure 2.

Additionally, when playing back a frame, conventionally, the relevant tracks were fixed and played back, for example, the first track, the second track, the third track, and the fourth track, but in continuous shooting mode, as mentioned above, the previous and subsequent pictures are Since there is a correlation, when playing a frame, the 1st track and @2 track, the 2nd track and 3rd track, the 3rd track and 4th track, etc.
By sequentially reproducing frames between ..., the number of continuous shots can be secured, making this an effective reproduction method.

Note that in the embodiment shown in FIG.
Although it has been described that the transfer is performed by switching by the switching device 43 according to the number of steps V, it may be configured so that each truck is transferred sequentially by one step V.

Furthermore, the same special photography as the object of the present invention can be obtained by field recording different pictures on individual tracks using a switching means that selectively switches between two tracks recorded in one track using a camera capable of frame recording. .

(Effects of the Invention) As described above, according to the electronic still camera of the present invention, the video signal recorded in the field is
In other words, the odd field F and the even field are read out alternately and recorded sequentially on the magnetic disk, making it possible to perform special photography using multiple exposures or decomposition photography in continuous shooting mode, which was previously possible with silver halide film cameras. You can get a good image.

[Brief explanation of drawings]

Figure 1 is a diagram showing an embodiment of the electronic still camera according to the present invention - Figure 2 is a diagram illustrating a reproduced image when the electronic still camera according to the present invention is taken in continuous shooting mode.
Figure a shows that when each track is played back sequentially, the second
The figure shows the case where frames are played back using two adjacent tracks. 18... Periodic signal generation circuit-19... Judgment circuit, 2
0...Control circuit, 22...Shirt release button, 26...Image sensor-34...Recording signal processing circuit. 40.41...Magnetic recording spatula F, 42...Magnetic disk. 43...Switcher, 90...Head transfer circuit. Figure 2 Figure 2 b n◆2

Claims (1)

[Scope of Claims] 1) An optical shutter that responds to an exposure instruction, an imaging means that images a subject by opening the optical shutter and stores a video signal corresponding to the subject image, and stores the video signal on a rotating recording medium. It has a recording control means and a recording means for field recording, and is managed so that odd fields and even fields of each video signal stored in the imaging means are read out alternately in response to a plurality of shutter releases. An electronic still camera characterized by: 2) The electronic still camera according to claim 1, wherein the video signal is recorded by a recording means having a two-channel head structure via a switching means that switches alternately.