JPH01270462A - Electronic still camera - Google Patents

Abstract

PURPOSE:To record all waveforms displayed on the screen of an oscilloscope by not only sweeping away unnecessary electric charge of an image pickup element but also inhibiting read-out for a set exposure time synchronously with a trigger signal from the external or turning-on of a release button. CONSTITUTION:A dial of an exposure time setter 21 is operated to set an exposure time TS equal to or longer than the time of one sweep of the oscilloscope. A trigger input terminal 27 is connected to the trigger output terminal of the oscilloscope. When a trigger signal 25 or a turning-on signal 33 of a release button 29 is inputted to a main CPU 1, unnecessary electric charge of an image pickup element 45 is swept away and read-out of this element 45 is inhibited for the set exposure time TS. After the exposure time TS, inhibition of read-out is released, and the video signal read out by a first read pulse 114 is recorded on a video floppy 83. That is, the waveform on the oscilloscope is preserved as a television signal.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Applications> The present invention relates to an electronic still camera, and more particularly to an improvement that enables the camera to photograph and record waveforms displayed on the screen of an oscilloscope.

<Prior Art> Conventionally, waveforms on the screen of an oscilloscope are often photographed with an instant camera using silver halide film.

On the other hand, with the recent development of electronic still cameras, it is being considered to photograph and record the same waveform with an electronic still camera.

<Problem to be solved by the invention> However, the sweep time of an oscilloscope can be set variably from an extremely short time to an extremely long time, and the waveform can be not only a repetitive waveform but also a sudden half-open waveform. Generally, the exposure time of an electronic still camera is not long. For example, the practical exposure time of an electronic still camera that does not use a special cooling device for suppressing dark current of an image sensor is 172 seconds at the maximum.

Therefore, even when trying to record the oscilloscope waveform with an electronic still camera, it was difficult to get the timing right, and only a portion of it could be recorded.

SUMMARY OF THE INVENTION In view of the problems of the prior art described above, it is an object of the present invention to provide an electronic still camera that can record all desired waveforms displayed on the screen of an oscilloscope.

Means for Solving the Problems> The electronic still camera according to the present invention has means for variably setting the exposure time, and an external trigger that sweeps unnecessary charges from the image sensor in synchronization with a signal or the release button being turned on. The present invention is characterized by comprising means for allowing the image sensor to be exposed and prohibiting reading during a set exposure time, and means for reading out the image sensor after the set exposure time has elapsed.

In the above configuration, when photographing a waveform, if the exposure time is longer than the 1 m subtraction time of the oscilloscope, for example, if the time axis is 10 scales and each scale is 10 m5ec, then i o o m5
Set it to ec or higher. For single waveforms, input the trigger signal (synchronization signal) from the oscilloscope. For repetitive waveforms, input the trigger signal or press the release button. At this time, unnecessary charges from the image sensor are first swept out, and reading is then prohibited for the set exposure time, so that all the waveforms for one sweep time are accumulated as charges in the image sensor.

After the exposure time has elapsed, the image sensor is read out, and as a result, the video signal of the entire waveform of one sweep time is recorded in the recording device.

Practical example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment based on a general color electronic still camera using a magnetic disk (video floppy) and equipped with a programmed automatic exposure function, to which a function for recording waveforms on an oscilloscope screen is added.

Therefore, a mode changeover switch 3 between normal shooting mode and oscilloscope shooting mode is connected to the main CPU for main control, and in the case of oscilloscope shooting mode, the AE-CPU for automatic exposure control is connected to the main CPU for main control.
Mechanical shutter 99 on 7! The iris 10 is opened and the iris 10 can be manually operated. Furthermore, in the case of oscilloscope shooting mode, the control signal 11 switches the gamma of the video signal processing circuit 13 to the characteristics shown in FIG. 3 to improve the contrast and S/N of the video, and the control signal 15 changes the chroma By stopping the operation of the signal frequency modulator 73 and widening the band of the fault level signal frequency modulation M67, it is possible to improve the resolution even though it is black and white recording.

In order to realize the present invention, a dial-type exposure time setting type 21 having a shutter speed scale was installed on the Ami-CPU 7.
2 and connect to the main CPU via AE-CPU7.
The exposure time setting value signal 23 is inputted to the exposure time setting signal 23. In addition, a trigger signal 25 from an external device such as an oscilloscope
A terminal (EXT TRG) 27 for inputting is provided and connected to the main CPU. 29 is a release button, which is connected to the main CP IJ 1. Note that a dial-type aperture setting device 31 is connected to the AE-CPU 7. When the main CPU is in the oscilloscope shooting mode, as shown in FIG.
G) Set the exposure time of the read prohibition signal 37 to 35 PJ2
After the elapse of this time, the readout prohibition is canceled and a recording trigger signal 41 is output to the recording gate 39.

The timing generator 35 drives an image sensor 45, for example, an interline type COD, via a driver 43.
usually! , the read pulse FSJe is repeatedly output in synchronization with vertical synchronization No. 41 VD. In the oscilloscope shooting mode, when the readout stop signal 37 is received from the main CPU, an extra readout (7 pulses 36 is output at the rising edge of the signal 37 as shown in FIG. 2 to eliminate unnecessary charges on the image sensor 45). During the period TS during which the read inhibit signal 37 is received, the read pulse is not output, and after this period elapses, the read pulse FS is output again.Anyway,
The read signal 47 is input to the video signal processing circuit 13, and an NTSC color video signal 49 and a magnetic recording signal 51°53.55 are output.

The NTSC color video signal 49 is output to a driver 59 of an electronic vinyl finder 57, passes through a buffer amplifier 61, and is output from a terminal 63 to the outside. Among the signals for magnetic recording, 51 is a luminance signal (including a synchronization signal), which is input to the frequency modulator 67 through a pre-emphasis circuit 1s65. 53 is R-Y signal, 55+f
B-Y ('f) are normalized by the circuit 69, and then sent to the frequency modulator 7 through the pre-emphasis circuit 7e.
Please enter 3. The output signals 75.77 of each frequency modulator 67.73 are mixed by a mixer 79 and input to a recording amplifier 81.

The video floppy 83 is operated at a constant speed of, for example, 3600 rpm by a motor 87 under the control of a servo motor 85, and the second r! ! As shown in J, the vertical synchronizing signal VD generated by the timing generator 35 and the video floppy 8
One PG pulse per rotation representing a rotational phase of 3 rotates in a predetermined phase relationship. 89 is a motor driver, 91 is a frequency detector, 93 is a PG coil, 951
This is an fPG pulse generation circuit.

The recording gate 39 receives the recording trigger signal 4 from the main CPU
As shown in FIG. 2, the recording command (RFC) signal 97
is given to the recording amplifier 81 and recorded on the magnetic head 99 Ii@
Flow 101 is caused to flow.

Note that 1e2 and 103 are optical systems such as lenses, 105 is a motor that drives the shutter 9, 1o7 is a motor that drives the iris 10, and 1o9 is a phase modulator for data recording. The phase modulator 109 is given data 111 such as the shooting date from the main CPU as necessary, and the DPSK
The modulated signal 113 is output to the mixer 79.

Next, the operation in oscilloscope photography mode will be explained.

(Attach the 11m child still camera to the oscilloscope using a mounting screw (not shown), and turn on switch 3 to set the oscilloscope photography mode.

As a result, the shutter 9 is opened, the iris 10 can be manually operated, the gamma has a high contrast characteristic, and the high resolution black and white recording mode is set.

(2) Next, operate the dial of the exposure time setting device 21 to set an exposure time TS of one sweep time of the oscilloscope or more. In addition, the electronic viewfinder 57
The aperture value of the iris 10 is set by operating the dial of the aperture setting device 31 while looking at the screen.

(3) Next, connect the trigger input terminal 27 to the trigger output terminal of the oscilloscope. In the case of a repetitive waveform, the release button 29 may be turned on.

When the trigger signal 25 or the ON signal 33 of the release button 29 is input to the main CPUI, unnecessary charges from the image sensor 45 are swept out, and the set exposure time TSf! Take a picture (
1i! Reading of element 45 is prohibited. Exposure time TS
After lapse of time, the readout prohibition is canceled, and the video signal read out with the first readout pulse 114 (see FIG. 2) is recorded on the video DVD 83.

That is, the oscilloscope waveform is stored as a television signal and can be played back and redisplayed on a television receiver or monitor when necessary.

Note that a switch 115 is connected to the main CPU, and only when this switch 115 is on, external trigger No. 1 and No. 2 are activated.
5 may be incorporated into the main CPUI to improve operability.

Furthermore, since the above embodiment is based on a general electronic still camera, it has two functions: normal shooting mode and oscilloscope shooting mode, but it goes without saying that a dedicated camera with a single function of oscilloscope shooting mode may also be used. . Further, the aperture setting word 31 is not necessarily necessary since the brightness yJ can be adjusted on the oscilloscope side. Furthermore,
Although the above embodiment does not mention the playback function, it is not necessarily necessary since it can be played back using another playback-only machine or a recording/playback machine. Of course, there is nothing wrong with adding a playback function to the camera itself.

Furthermore, in the above embodiment, the video signal is recorded on a magnetic disk, but the recording medium is not limited, and may be, for example, a digital electronic still camera that A/D converts and records the video signal on a semiconductor memory. .

<Effects of the Invention> According to the present invention, since the shooting timing always matches the trigger signal from the oscilloscope, it is possible to minimize the exposure time of the camera, and even with electronic still cameras that cannot set long exposure times. , be able to photograph and record the waveforms displayed on both sides of the oscilloscope.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is a timing chart for explaining the operation, and FIG. 3 is a diagram showing an example of gamma characteristics. In the drawing, 1 is the main CPfJ, 21 is the exposure time setting device,
25 is a trigger signal, 27 is an input terminal, 29 is a release button, 36 is a pulse for sweeping out unnecessary t4W, 37 is a read inhibit signal, 45 is an image sensor, 51 is a brightness signal, 6
7 is a frequency modulator, 81 is a recording amplifier, 83 is a video floppy disk, 99 is a magnetic head, Ts is an exposure time, and FS is a read pulse. -,423-

Claims (1)

[Claims] An electronic still camera that records a still image image signal from an image sensor in a recording device, comprising means for variably setting an exposure time and synchronizing with an external trigger signal or turning on of a release button. , an electronic still comprising means for sweeping out unnecessary charges from an image sensor and prohibiting readout during a set exposure time, and means for reading out the image sensor after the set exposure time has elapsed. camera.