JP2718409B2 - Video recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video recording device, and more particularly, to a video recording device for recording a video signal on a recording medium. 2. Description of the Related Art As a high-speed imaging apparatus using a video camera, there is known a method of increasing both a vertical scanning frequency _fVS and a horizontal scanning frequency _fHS to an imaging section by the same magnification. [0003] However, simply f _VS , f
_If you increase the _HS , the signal frequency will also increase, so
If the signal processing circuit of the camera must have a wide band, and if it is desired to record an output video signal, a wide band recording device must be used, and a very expensive recording device is required. The monitoring device must also use a dedicated device for high speed. An object of the present invention is to provide a video recording device capable of recording an image taken at high speed in such a background. A video recording device according to the present invention is a device for recording a video signal having a horizontal synchronizing signal and a vertical synchronizing signal, wherein 1 / n of the period of the vertical synchronizing signal. (N is an integer of 2 or more), a first recording mode for recording on a recording medium a first video signal including n images captured in each vertical synchronization period, and a single image for each. It has a second recording mode in which a second video signal included in the vertical synchronization period is recorded on the recording medium. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram of a recording / reproducing apparatus according to an embodiment of the present invention. In the following description, n and m are integers. Before describing the recording / reproducing apparatus shown in FIG. 1, a high-speed imaging apparatus for generating an image signal will be described in order to understand the format of a recorded image signal. FIG. 2 shows a configuration diagram of an interline CCD image pickup device 10 serving as an image pickup device of the image pickup apparatus. In FIG. 2, reference numeral 12 denotes a large number of photoelectric conversion cells arranged vertically and horizontally. 14 is a CCD for vertical transfer,
16 is a gate electrode, 18 is a horizontal transfer CCD, 20 is a buffer amplifier, and 22 is an output terminal. Although this structure itself is publicly known, in this embodiment, in the case of high-speed shooting, two horizontal transfer CCDs 18 are provided at 1 / m from the output terminal 22 side (m = 2 in the example shown, the center). Divide and use. The right CCD is denoted by reference numeral 18A, and the left CCD is denoted by reference numeral 18B. Φ _V is CCD for vertical transfer
Φ _H1 is the vertical transfer signal for the horizontal transfer CCD 1
A right-shifted horizontal transfer signal for 8A, Φ _H2 is a left-shifted (right-shifted in case of normal speed shooting) horizontal transfer signal for the horizontal transfer CCD 18B, and Φ _R is a gate pulse. FIG. 3 shows the timings of Φ _V and Φ _{R in} the case of high-speed shooting with respect to the vertical synchronizing signal f _v of the video signal obtained at the normal shooting speed. These Φ _V , Φ _R ,
Φ _H1 , Φ _H2, etc. are synchronized signal generation circuits (SSG) 4
Supplied from 8. When photographing at a normal speed, the vertical synchronizing signal f
_A gate pulse Φ _R is applied within the vertical blanking period in synchronization with _V, and the charges in each cell 12 are simultaneously transferred to the vertical transfer CCD 14.
Then, the horizontal transfer C is applied one horizontal line at a time by applying a vertical transfer pulse Φ _V synchronized with the horizontal synchronizing signal f _H.
The video signal S is output to the output terminal 22 by being transferred to the CD 18 and transferred to the right side by the horizontal transfer pulses Φ _H1 and Φ _H2 . Next, the operation in the high-speed photographing mode will be described.
However, the case of four times the normal shooting speed (that is, n = 4) is taken as an example. In this case, the vertical scanning signal for the image sensor 10 is increased to four times the frequency of a normal case, and as shown in FIG.
Four gate pulses Φ in one vertical period at normal shooting speed
_{Apply R.} The charge transferred from the cell 12 to the vertical transfer CCD 14 by the gate pulse Φ _R is a vertical transfer signal Φ
_V (frequency f ₂ ) is sent to the horizontal transfer CCD 18 one horizontal line at a time. Note that the frequency of the vertical transfer signal Φ _V at this time is 2
(= N / m) times the frequency. CCD18 for horizontal transfer
A signal corresponding to 水平 horizontal line of A is sent to the output terminal 22 by the horizontal transfer signal Φ _H1 . On the other hand, horizontal transfer CC
The signal corresponding to the 1/2 horizontal line of D18B is sent in the reverse direction by the horizontal transfer signal Φ _H2 and is discarded. The frequency f ₁ (> f ₂ ) at the stage when about half of the vertical scanning line is read out
High-speed vertical transfer signal φ _V
The charge remaining in 14 is swept out. In this sweeping, the transfer direction of the horizontal transfer signal Φ _H1 may be reversed to the left in FIG. 2, or the signal from the output terminal 22 may be removed by a gate (not shown) or the like. After this sweep,
The gate pulse Φ _R is applied again to read out the charge of the cell 12. [0011] image signal obtained from the output terminal 22 of the image pickup device 10 by the high-speed imaging, as shown in FIG. 4 (a), 4 times the frequency of the vertical synchronizing signal V _H normal television signals, horizontal synchronization The frequency of the signal H _H is twice as high as that of a normal television signal. However, each output screen is a small screen having a resolution of 1/2 in the horizontal direction and a resolution of 1/2 in the vertical direction, as compared with shooting at a normal speed. The small screens A, B, C, and D in FIG. 4A are temporally continuous. The high-speed photographing signal obtained in this manner has a horizontal synchronizing signal and a vertical synchronizing signal having the same frequency as in the case of the normal photographing speed by the configuration shown in FIG. 5, and becomes a video signal having the image arrangement shown in FIG. Convert. FIG. 5 shows an image pickup apparatus including the image pickup device. This apparatus will be described below. When the imaging device 10 is performing the normal photographing operation, the switch 46 is connected to the N side, and the video signal output from the output terminal 22 of the imaging device 10 is supplied to the signal processing circuit 4 via the N side terminal of the switch 46.
2 is supplied. On the other hand, the video signal output from the output terminal 22 by the high-speed shooting operation of the image sensor 10 is A / D
The signal is converted by the converter 30 into a digital signal. Switch 3
2 sequentially switched by a signal V _H indicating the vertical scanning period at the time of high-speed shooting generated from SSG48, sequential output signal of the A / D converter 30 every vertical scanning period at the time of high-speed imaging, 1 / n M capacity of the field (2 in the example shown)
) Of memories 34 and 36. Memory 34, 36
May be a random access type or a first-in first-out type. When reading the signals from the memories 34 and 36, the switch 3 which is switched by the signal H _H indicating the horizontal scanning cycle at the time of high-speed shooting supplied from the SSG 48 is used.
At 8, the outputs of the memories 34 and 36 are switched and read alternately and applied to the D / A converter 40. D / A converter 4
The analog output of 0 is sent to the signal processing circuit 42 via the switch 46 that has been switched to the H side. In the circuit 42, a synchronizing signal of a normal television signal is added, and further, signal processing well known in the field of a video camera is performed. Adopting a configuration in which signal processing is performed after D / A conversion has the advantage that color signal processing and the like can be shared with video signal processing at normal shooting speed. Of course, the necessary signal processing may be performed in the state of a digital signal. The video signal thus obtained is shown in FIG.
As shown in (2), a 2 × 2 small screen is a video signal included in one screen. The output signal of the signal processing circuit 42 is output from a terminal 44. Since the signal has a synchronizing signal having the same frequency as that of a normal television signal of the NTSC system or the like, it is displayed on a normal monitor or displayed on a normal VTR. Recording is possible. The apparatus according to the present invention shown in FIG.
This utilizes a head helical scan type VTR. A video signal obtained by normal shooting or high-speed shooting via an input terminal to which an output terminal 44 of the image pickup apparatus is connected is converted into a luminance signal by a recording signal processing circuit 54 as is well known in the above-mentioned VTR. A process of performing FM modulation and frequency-converting the carrier chrominance signal to the low frequency band is performed. The adder 56
The video signal processed by the circuit 54 is multiplexed with an identification signal indicating whether the video signal is obtained by normal shooting or high-speed shooting.
A circuit 52 generates this identification signal in response to a manual operation or an instruction from the imaging device. The identification signal is multiplexed with the video signal by a method such as multiplexing it as a pilot signal with a video signal or multiplexing it as a pulse signal during a vertical blanking period. The video signal in which the identification signal is multiplexed is supplied to a recording / reproducing unit 58, and is sequentially recorded on a magnetic tape running at a predetermined speed by a pair of rotary heads having different azimuths as is well known. The operation of reproducing a video signal by the recording / reproducing section 58 will be described below. It is assumed that the recorded video signal is due to normal shooting. In accordance with the identification signal separated by the identification signal separation circuit 62, the switch 66 is connected to the N side, and the video signal that has been subjected to the well-known signal processing by the reproduction signal processing circuit 60, that is, the luminance signal, is FM-demodulated, and The video signal whose signal has been returned to the original band is supplied to the terminal 68 via the N-side terminal of the switch 66 and output to a monitor or the like. At this time, the capstan control circuit 6
Reference numeral 4 controls a capstan (not shown) so that the magnetic tape is conveyed at the same speed as during recording according to the identification signal.
This operation is exactly the same as the conventional VTR. Next, the operation for reproducing a video signal captured at a high speed will be described. At this time, the video signal processed at the same time by the reproduction signal processing circuit 60 has four small screens A, B, C, and D in one field as shown in FIG. 4B. In the illustrated device, the four small screens are converted into a video signal which sequentially includes one screen at a time in one field so that each small screen can be sequentially displayed at the position indicated by A in FIG. Is what you do. That is, a reproduction signal for one field (for four small screens) is obtained during a period corresponding to four fields of the reproduction video signal, and this is output as a four-field video signal. The identification signal separated by the separation circuit 62 connects the switch 66 to the H side, and causes the capstan control circuit 64 to run the magnetic tape at a speed 1/4 that at the time of recording. FIG. 6 shows the state of the trace of the rotary head on the magnetic tape at this time. The solid line in FIG. 6 indicates the boundary between the tracks, TR1 is a plus azimuth track, and TR2 is a minus azimuth track. T ₁ , T ₃ , T ₅ , and T ₇ shown by dashed lines are the center lines of the trace trajectory by the plus azimuth head, and T ₂ , T ₄ , T ₆ , and T ₈ shown by the broken lines are the trace trajectories by the minus azimuth head. It is the center line. The video signal processed by the reproduction signal processing circuit 60 is input to an A / D converter 84, digitized, and input to a switch 86. The switch 86 is switched by a signal obtained by doubling the frequency of the horizontal synchronizing signal in the reproduced signal by the multiplier 76 composed of a PLL or the like. The first half of each horizontal scanning line is stored in the 2 / n field memory 88 and the second half thereof. To the 2 / n field memory 90 respectively. The horizontal synchronizing signal is obtained by separating the composite synchronizing signal separated by the synchronizing signal separating circuit 70 by the horizontal synchronizing circuit 72. Reference numeral 80 denotes a write control circuit for the memories 88 and 90, which controls its write timing and write address.
A read control circuit 82 controls the read timing and read address of the memories 88 and 90. FIG. 7 shows timings of writing (W) and reading (R) of the memories 88 and 90.
The chart is shown. Periods T _{1 to} T ₈ in FIG. 7 correspond to periods in which reproduced signals are obtained on the trace loci T _{1 to} T ₈ in FIG. The memories 88 and 90 write video signals in the periods T ₃ and T ₆ , respectively.
In (b), video signals corresponding to A and B, and in the latter half, C and D are written, respectively. By the operation of the switch 32, A and C are stored in the memory 88, and B and D are stored in the memory 90.
Is written. A ₁ in FIG.
B ₁ , C ₁ , and D ₁ are video signals recorded on track TR ₁ , and A ₂ , B ₂ , C ₂ , and D ₂ are video signals recorded on track TR 2. , B,
C and D are supported. After tracing the trace locus T ₈ , the relationship between the track and the trace locus again becomes T
₁ , but corresponding periods are indicated by T ₁ ′, T ₂ ′,... In FIG. Also in this case, writing is performed at T ₃ ′ and T ₆ ′. The video signal written in the memory 88 in the period T ₃ is in the order of the period _{T 3, T 4, T 5} , each one small screen at a time to _{T 6 A 1, B 1,} C 1, D 1 Is read.
This readout timing is 1 / center of each one-field period.
This is a two-field period, and is a half period at the center of each horizontal scanning period. The outputs of the memories 88 and 90 are alternately output by the switch 92 every one field period and supplied to the D / A converter 94. The write control circuit 80 and the read control circuit 82 operate on the above-described reproduced horizontal synchronizing signal and the reproduced vertical synchronizing signal separated by the vertical synchronizing circuit 74 from the composite synchronizing signal. Switch 9
2 is controlled by a control signal shown in FIG. 7 obtained by inputting the reproduced vertical synchronizing signal to the flip-flop 78. The video signal output from the D / A converter 94 is such that small screens A, B, C and D are sequentially displayed at the center of the output screen as shown in FIG. 4
A slow motion image having twice the information density in the time axis direction can be obtained. The output of the D / A converter 94 is output from the terminal 68 via the H side of the switch 66. In the embodiment shown in FIG. 1, 2 / n field memories are 2
Although there is provided a random access memory, only one may be provided. As a matter of course, it is also possible to perform conversion only by address control using a memory having a capacity of one field. The portion of the background G in FIG. 4C can be used for displaying various data such as time and field number. Although the image is somewhat coarse, the image may be enlarged and displayed. When n and m are selected so as to satisfy the relationship of n = m ² , the aspect ratio of each image can be made the same as the image at the normal shooting speed. The case where n = 4 and m = 2 has been described.
Any number can be used as long as it is a multiple of. As can be easily understood from the above description, according to the present invention, a high-speed photographed image can be recorded using an ordinary video recording device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration block diagram of an embodiment of the present invention. FIG. 2 is a configuration diagram of an example of an imaging device 10 of the high-speed imaging device. FIG. 3 is a timing chart of a transfer signal of the image sensor of FIG. 2; FIG. 4 is a screen display diagram at each stage. FIG. 5 is a diagram illustrating a configuration example of an imaging device that processes an output of the imaging device in FIG. 2; FIG. 6 is a diagram showing a trace locus on a magnetic tape by the apparatus shown in FIG. 1; FIG. 7 is a timing chart of writing to and reading from a memory in the device shown in FIG. 5; [Explanation of Signs] 58: recording / reproducing unit 60: reproduced signal processing circuit 62: identification signal separating circuit 64: capstan control circuit 68: output terminal 84: A / D converters 88 and 90: memory 94: D / A conversion vessel

Claims (1)

(57) [Claims] An apparatus for recording a video signal having a horizontal synchronizing signal and a vertical synchronizing signal, comprising:
/ N (n is an integer of 2 or more), a first recording mode for recording on a recording medium a first video signal including n images captured in each vertical synchronization period, and a single image And a second recording mode for recording a second video signal containing the video signal in each vertical synchronization period on the recording medium. 2. 2. The video recording apparatus according to claim 1, wherein an identification signal for identifying the first and second recording modes is recorded on the recording medium together with the first and second video signals.