JPH0767158B2 - Video camera system with electronic shutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a video camera system having an electronic shutter, and is devised so that a still image taken using the electronic shutter can be individually recorded.

<Prior Art> Some video cameras of recent years, particularly video cameras having a CCD as an image pickup device, have an electronic shutter, and a still image is recorded by appropriately operating the electronic shutter during shooting of a moving image. The shots to be recorded can be individually photographed in the same state as when recording with an electronic still camera.

One screen of NTSC television, 1/60 for one field
Since it is made in seconds, you can usually think of the shutter speed as 1/60. That is, the signal charge accumulated in one pixel of the CCD is photoelectrically generated by the incident light in the period of 1/60 seconds, and is read once every 1/60 seconds.

Most of the image pickup devices in current video cameras are called field storage, and have a shutter speed of 1/60 second, but some have a shutter speed of 1/30 second. This is 1
The signal charge of a pixel is read out every 1/30 seconds, and this is called frame accumulation to distinguish it from the former.

In any case, in the conventional video camera, if the subject or the video camera being shot moves within 1/30 or 1/60 seconds, the image will be blurred. On the other hand, in an image sensor such as CCD, the time for signal accumulation can be changed by a control signal. In the electronic shutter, the signal storage time of 1/60 or less can be arbitrarily selected, and this signal storage time is referred to as the shutter speed of the electronic shutter.

Here, the principle of the electronic shutter in the field storage CCD will be described. As shown in FIG. 4, the signal charge accumulated by the light of one pixel of the CCD increases with time, and linearly increases when the amount of light is constant, 1/60
After a lapse of seconds, the electric charge C ₆₀ is accumulated. Now, assuming that the shutter speed of the electronic shutter is set to t ₁ , (1 / 60−
At time t ₁ ), that is, time t _{2 in} FIG. 4, the electric charge C _s accumulated so far is discarded from the pixel portion of the CCD to, for example, the overflow drain. As a result, the accumulated charge in the pixel portion becomes zero. However, since the light continuously strikes the CCD, the accumulated charge starts to increase again at the same inclination, and the charge C _t is accumulated after the shutter speed t ₁ of the electronic shutter has elapsed. At this time, if a field shift pulse is given, the charge C _t can be read out as a signal charge.

Wherein between FIG. 4 t _2, as a method which does not accumulate charges in the CCD, for example, as shown in FIG. 5, CCD of overflow based on the vertical synchronizing pulse V _s of the immediately after the electronic shutter is operated -For example, applying a sweep pulse P _s with the same period as the horizontal synchronization signal to the DC bias of the drain, and unnecessary charges are CCD
It is known how to get out of it. That is, in the field while shooting a still image, from the rear edge of the vertical synchronizing signal V _s (1 / 60-
The sweep pulse is supplied to the CCD during the period (t ₁ ), and the charge C _t accumulated during the latter half period of the same field corresponding to the shutter speed t ₁ is read out as a signal charge.

Thus, in a video camera with an electronic shutter, the shutter speed is set appropriately, and a still image mode can be selected during the shooting of a moving image to appropriately shoot a still image. The video signal at this time is such that a field shot in the still image mode is mixed in the middle of a field shot in the moving image mode.

<Problems to be Solved by the Invention> As described above, since fields of still images shot by a video camera with an electronic shutter according to the related art are mixed in the middle of fields shot in the moving image mode, video tapes and the like may be used. When recorded on a recording medium, it is difficult and time consuming to extract only the field of this still image.

In view of the above-mentioned problems of the prior art, the present invention easily extracts a signal corresponding to a still image from a video signal in which a field shot in the moving image mode and a field shot in the still image mode are mixed and the still image is extracted. An object of the present invention is to provide a video camera system having an electronic shutter capable of easily specifying a field where an image exists.

<Means for Solving the Problems> The configuration of the present invention that achieves the above-mentioned object is to record a moving image, which is image information read out from the image sensor at regular intervals by selecting a moving image mode, on a recording medium such as a magnetic tape. The electronic shutter configured to drive the electronic shutter of the image sensor by recording the image on the recording medium and to select the still image mode, and to record the still image, which is the image information read in an arbitrary time width, on the recording medium together with the moving image. A video camera system having: a switch unit that operates in the still image mode; and a storage unit that reads and stores image information output from the image sensor by the operation of the switch unit, and records in the still image mode. The storage means is configured to store a still image together with the medium, and the image information and the recording medium on which the image information is recorded. Position information generating means for generating position information corresponding to the position, synthesizing means for synthesizing the position information and video information output from the image pickup device, switch means for operating in the still image mode, and synthesizing means. Storage means for reading and storing image information including position information that is synthesized by the operation of the switch means, and is configured to store a still image in the storage means together with the recording medium in the still image mode. Characterize.

<Operation> According to the present invention having the above configuration, in the still image mode,
Video information output from the image sensor is read into the storage means via the switch means. That is, still images are individually stored in the storage means.

Further, according to the present invention, in the still image mode, the image information output from the image pickup device is superimposed on the position information of the recording medium and is read into the storage means via the switch means. That is, the still image is individually stored in the storage means together with the position information of the recording medium in which the still image is present.

<Examples> Examples of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention. As shown in the figure, the switch 1 selects the moving image mode. By operating this switch 1,
The driver 3 is driven via the system controller 2 so that the accumulated charge accumulated in each pixel of the image pickup device 4 which is a CCD with an electronic shutter is read every 1/60 seconds. At this time, the accumulated charges read from the image pickup device 4 are supplied to the signal processing circuit 6 via the preamplifier 5, converted into a video signal by the signal processing circuit 6, and then recorded by the recording amplifier 7.
And, it is recorded on the magnetic tape 9 which is a recording medium via the video head 8.

The switch 10 selects the still image mode, and by operating the switch 10, the electronic shutter control unit 11, the switch 12, and the memory control unit 13 are respectively driven via the system controller 2. The electronic shutter control unit 11 controls the electronic shutter of the image sensor 4 at the set shutter speed t ₁ . At this time, the accumulated charges read from the image sensor 4 every 1/60 seconds are recorded on the magnetic tape 9 in the same manner as in the moving image mode.

On the other hand, in this still image mode, the switch 12
Is being driven (closed), the accumulated charges are read and stored in the image memory 16 which is a storage means via the A / D converter 14, the switch 12 and the connector 15. The image memory 16 is
It can be easily formed by an IC card or the like having an appropriate storage capacity (for example, several fields), and the accumulated charges corresponding to each still image are stored in an address designated by the memory control unit 13. . Also, the image memory 16
Is stored in the memory cartridge 17, and can be attached to and detached from the connector 15 in this state.

In this embodiment, in the moving image mode, the image information of the subject is recorded on the magnetic tape 9 in the same manner as in the conventional case.

On the other hand, in the still image mode, the image information at this time is recorded on the magnetic tape 9 as well as in the image memory 16 as in the case of the moving image mode. Therefore, if the information in the image memory 16 is read, it can be reproduced as a still image on the monitor, and a hard copy can be prepared as necessary. However, in the present embodiment, the accumulated charge read from the image sensor 5 is stored in the image memory 16.
Since it is stored only in the state of being A / D converted, it is necessary to perform signal processing and convert it into a video signal when reproducing the video information corresponding to the accumulated charges.

2 (a) to 2 (d) are waveform diagrams showing the waveforms of the respective portions of this embodiment. 2 (a) is a vertical synchronization pulse V _s which serves as a reference for the read timing of the image sensor 4, FIG. 2 (b) is a sweep pulse P _s for explaining the operation of the electronic shutter, and FIG. 2 (c). 2 (d) is sent from the system controller 2 and the switch 12 and the memory controller 13
The switching pulses P _sw1 and P _sw2 for driving The switching pulse P _sw1 is "H" (high) for one field period so that a still image for one field is read into the image memory 16.
In this state, the switch 12 and the memory control unit 13 are driven. The switching pulse P _sw2 repeatedly drives the switch 12 and the memory control unit 13 over several fields so as to continuously read still images of several fields into the image memory 16 for one field period. There is.

FIG. 3 is a block diagram showing a second embodiment of the present invention. In the figure, those parts which are the same as those corresponding parts in FIG. 1 are designated by the same reference numerals, and a overlapping description will be omitted. As shown in FIG. 2, the moving image recording system has the same configuration as that of the above embodiment. Image memory of this embodiment
Reference numeral 16 denotes a video signal which has been subjected to predetermined processing by the signal processing circuit 6.
A / D conversion is performed by the A / D converter 14 and read via the switch 12. The tape counter 18 detects the winding amount of the magnetic tape 9 and displays the information on the tape position display device.
It is designed to be sent to 19. Tape position indicator 19
Is a circuit for synthesizing a video signal representing the position information of the video information recorded on the magnetic tape 9 based on the information of the tape counter 18, for example, the video information at the position of minutes and seconds from the start of winding the magnetic tape 9. It is designed to send to 20. The synthesizing circuit 20 synthesizes the image information and the image signal representing the position information, and associates the image information with the position information on the magnetic tape 9 on which the information is recorded.

In this embodiment, in the moving image mode, the image information of the subject is recorded on the magnetic tape 9 in the same manner as in the above embodiment.

On the other hand, in the still image mode, the image information at this time is recorded on the magnetic tape 9 as in the case of the moving image mode, and is also combined with the position information and stored in the image memory 16. Therefore, it is the same as the above-mentioned embodiment in that if the information in the image memory 16 is read out, it can be reproduced as a still image on the monitor and a hard copy can be prepared if necessary. Further, according to the present embodiment, it is possible to simultaneously display at which position on the magnetic tape 9 the still image being reproduced is stored. More specifically, this function composites and records information on the position on the magnetic tape where the portion recorded in the still image mode is recorded in the image memory that is easier to search than the magnetic tape. By reproducing the memory, it is possible to easily confirm the still image recording position on the magnetic tape (for example, information on how many minutes and seconds the still image is recorded from the beginning of winding). As a result, it is possible to quickly search by using the functions such as fast-forwarding and rewinding, excluding the trouble and time of confirming the still image recording unit on the monitor while sequentially reproducing the magnetic tape from the beginning.

The image memory 16 may read the accumulated charges read from the image pickup device 4 by A / D conversion as shown in the first embodiment, or as described in the second embodiment. The video signal obtained by processing the accumulated charges by the signal processing circuit 6
The A / D conversion may be performed for reading, but in the former case, it is necessary to perform the same processing as that performed by the signal processing circuit 6 when reproducing the video information stored in the image memory 16.

Further, in the above embodiment, the drive state of the switch 12 when the still image mode is selected can be controlled arbitrarily.
For example, only the video information of the first field may be read every time the still image mode is selected, or only the video signal of any field while the still image mode is selected may be read. The video signal of the field may be continuously or intermittently read while the mode is selected.

<Effects of the Invention> As described in detail with the embodiments above, according to the present invention, each field (or frame) is used as video information even in the moving image mode or the still image mode in which the electronic shutter is operated. ) Can be recorded as a continuous video signal, and so-called still image information in the case of the still image mode can be individually stored in a dedicated storage means. It can be done easily. Further, since the position information in the recording medium in which the still image information is recorded can be combined with the still image information, the still image in the recording medium is recorded by reproducing the still image information in this case. It is possible to easily display and specify the position.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention, FIG. 2 is a waveform diagram of each part, FIG. 3 is a block diagram showing a second embodiment of the present invention, and FIG. FIG. 5 is an explanatory diagram for explaining the principle of the electronic shutter, and FIG. 5 is a waveform diagram showing the operation timing of the electronic shutter. In the drawing, 4 is an image sensor, 12 is a switch, 16 is an image memory, 18 is a tape counter, and 20 is a composition circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // G11B 20/02 K 9294-5D

Claims (2)

[Claims] 1. An electronic device of an image pickup device, comprising recording a moving image, which is image information read out from the image pickup device at regular intervals by selecting a moving image mode, on a recording medium such as a magnetic tape, and selecting a still image mode. In a video camera system having an electronic shutter configured such that a shutter is driven and a still image, which is video information read out at an arbitrary time width, is recorded together with the moving image on the recording medium, a switch means operating in a still image mode. And storage means for reading and storing image information output from the image pickup device by the operation of the switch means, and configured to store a still image in the storage means together with the recording medium in the still image mode. A video camera system having an electronic shutter. 2. An electronic device of an image pickup device by recording a moving image, which is image information read out from the image pickup device at regular intervals by recording a moving image mode, on a recording medium such as a magnetic tape and selecting a still image mode. In a video camera system having an electronic shutter configured to record a still image, which is video information read out in an arbitrary time width with a shutter driven, on the recording medium together with a moving image, the video information and a recording in which the video information is recorded. Position information generating means for generating position information corresponding to the position of the medium, synthesizing means for synthesizing the position information and video information output from the image sensor, and switch means operating in the still image mode, A storage unit that reads and stores image information including position information that is synthesized by the synthesizing unit in association with the operation of the switch unit, and is stationary. A video camera system having an electronic shutter, characterized in that a still image is stored in a storage means together with a recording medium in the image mode.