JP2550567B2 - High-speed imaging device - Google Patents

Description

The present invention relates to a high-speed image pickup apparatus, that is, an image pickup apparatus which outputs a video signal having a high information density in the time axis direction.

[Conventional technology and its problems]

As a high-speed image pickup apparatus using a video camera, a method is known in which both the vertical scanning frequency _fVS and the horizontal scanning frequency _fHS to the image pickup section are increased by the same magnification. Moreover, simply f
_{If VS} and _fHS are increased, the signal frequency will also increase, so the signal processing circuit of the camera must have a wider bandwidth.If you want to record the output video signal, use a wideband recording device. Must be done, and a very expensive recording device is required. Also, the monitor device must be a dedicated device compatible with high speed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-speed image pickup device which outputs a video signal having a high time-axis direction information density and which can be used in an inexpensive device without requiring a dedicated device as a video recording device or a monitor device.

A second object of the present invention is to provide a high-speed image pickup device which can be easily used also as an image pickup device at a normal photographing speed.

[Means for solving problems]

The high-speed image pickup apparatus according to the present invention has a frequency that is n times (n is an integer of 2 or more) a frequency of a vertical sync signal of a video signal to be output and m times (m is a frequency of a horizontal sync signal of the video signal). An image pickup unit that outputs a photoelectric conversion signal in accordance with a horizontal scanning signal of an integer of 2 or more, which is a divisor of n, and an output signal from the image pickup unit are temporarily stored. and / m converting means for converting into a video signal including a total of n images and outputting.

[Action]

The time resolution is increased by n times by increasing the vertical scanning signal by n times the vertical synchronization frequency. At this time, the number of output pixels in the horizontal direction is 1 / m and the number of scanning lines in the vertical direction is m / n by multiplying the horizontal scanning signal by m times the horizontal synchronizing frequency. From the output signals of the image pickup means, a total of n image signals of m in the horizontal direction and n / m in the vertical direction are collected to form a video signal for one screen. Therefore, the horizontal synchronizing signal and the vertical synchronizing signal are formed. By adding a signal, it is possible to display or record on a monitor device or a video recording device which has been conventionally used. Further, if the signal reading speed from each pixel on the image pickup surface is set to be the same as in the case of shooting with a conventional image pickup apparatus, high-speed shooting can be performed using the conventional image pickup tube or solid-state image pickup device as it is. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a schematic block diagram of an image pickup apparatus according to an embodiment of the present invention, and FIG. 2 shows an example of an image pickup element constituting the image pickup section of the embodiment shown in FIG. In the following description, n and m are integers.

Before describing FIG. 1, the interline CCD image sensor 10 illustrated in FIG. 2 will be described. In FIG. 2, 12
Is a photoelectric conversion cell, and a large number are arranged vertically and horizontally. 14 is a vertical transfer CCD, 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 known, in the present embodiment, two horizontal transfer CCDs 18 are provided at a position 1 / m from the output terminal 22 side (m = 2 in the illustrated example, so the center) in the case of high-speed shooting. Divide into and use. The CCD on the right side is labeled 18A, and the CCD on the left side is labeled 1
Marked with 8B. Φ _V is a vertical transfer signal for the vertical transfer CCD 14, Φ _H1 is a rightward horizontal transfer signal for the horizontal transfer CCD 18A, and Φ _H2 is a leftward shift for the horizontal transfer CCD 18B (right for normal shooting speed shooting). Direction shift)
Horizontal transfer signal, Φ _R is a gate pulse. Figure 3 shows the vertical sync signal of the video signal obtained at the normal shooting speed.
The timings of Φ _V and Φ _{R in} the case of high-speed shooting for f _V are shown. These Φ _V , Φ _R , Φ _H1 , Φ _H2, etc. are given from a synchronization signal generation circuit (SSG) 48 described later.

When shooting at normal speed, the gate pulse Φ _R is applied within the vertical blanking period in synchronization with the vertical sync signal f _V , the charges of each cell 12 are simultaneously transferred to the CCD 14 for vertical transfer, and then the horizontal sync signal. By applying a vertical transfer pulse Φ _V synchronized with f _H , each horizontal line is transferred to the CCD 18 for horizontal transfer, and the horizontal transfer pulses Φ _H1 and Φ _H2 are all transferred to the right side to output the video signal S to the output terminal 22. Is output.

Next, the operation in the high-speed shooting 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
The frequency is doubled, and as shown in FIG. 2, four gate pulses Φ _R are applied in one vertical period at the normal photographing speed. Gate pulse [Phi CC vertical transfer from cell 12 by _R
The charge transferred to D14 is the vertical transfer signal Φ _V (frequency f ₂ )
Then, each horizontal line is sent to the CCD 18 for horizontal transfer.
The frequency of the vertical transfer signal Φ _V at this time is 2 (= n / m) times the frequency of the vertical transfer signal during the above-described normal shooting. A signal for 1/2 horizontal line of the CCD 18A for horizontal transfer is sent to the output terminal 22 by the horizontal transfer signal Φ _H1 .
On the other hand, the signal for 1/2 horizontal line of horizontal transfer CCD18B is
It is sent in the opposite direction by the horizontal transfer signal Φ _H2 and discarded.
At the stage when about 1/2 of the vertical scanning line is read, the frequency f
A high speed vertical transfer signal Φ _V of ₁ (> f ₂ ) is applied to sweep out the charges remaining in the vertical transfer CCD 14. In this sweeping, the transfer direction by 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 sweeping out, the gate pulse Φ _R is applied again to read out the charge of the cell 12.

As shown in FIG. 4 (a), the video signal obtained from the output terminal 22 of the image pickup device 10 by this high-speed shooting has a vertical synchronizing signal V _{H having} a frequency four times that of a normal television signal and a horizontal synchronizing signal H H. The frequency of _H becomes twice the signal of a normal television signal. However, each output screen is a small screen with half the horizontal resolution and half the vertical resolution compared to normal speed shooting. The small screens A, B, C and D in FIG. 4 (a) are temporally continuous. The high-speed video signal thus obtained has the horizontal synchronizing signal and the vertical synchronizing signal of the same frequency as in the case of the normal photographing speed by the configuration shown in FIG.
It is converted into a video signal having an image arrangement as shown in FIG.

FIG. 1 will be described. The switch 46 is connected to the N side when the image sensor 10 is performing a normal shooting operation, and the video signal output from the output terminal 22 of the image sensor 10 is supplied to the signal processing circuit 42 via the N side terminal of the switch 46. To be done. 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 converted into a digital signal by the A / D converter 30. The switch 32 is sequentially switched by a signal V _H generated by the SSG 48, which indicates a vertical scanning period during high-speed shooting, and the output signal of the A / D converter 30 is sequentially 1 / n for each vertical scanning period during high-speed shooting. M of field capacity (two in the example shown)
Applied to the memories 34 and 36 of. The memories 34 and 36 may be of a random access type or a first-in first-out type. When reading the signals of the memories 34 and 36, the outputs of the memories 34 and 36 are alternately read by switching the outputs of the memories 34 and 36 by the switch 38 which is switched by the signal H _H indicating the high-speed horizontal scanning period supplied from the SSG. Apply to transducer 40. D / A converter
The switch whose analog output of 40 is switched to H side
It is sent to the signal processing circuit 42 via 46. In the circuit 42, a synchronizing signal of a normal television signal is added, and further signal processing well known in the field of video cameras is performed. D /
By adopting a configuration that performs signal processing after A conversion,
There is an advantage that the color signal processing and the like can be shared with the video signal processing at the normal shooting speed. Of course, the necessary signal processing may be performed in the state of digital signals.

The video signal thus obtained is a video signal in which a 2 × 2 small screen is included in one screen as shown in FIG. 4 (b).

The output signal of the signal processing circuit 42 is output from the terminal 44, but since it has a synchronizing signal of the same frequency as a normal television signal such as NTSC system, it can be displayed by a normal monitor device and recorded by a normal VTR. Is.

FIG. 5 shows an example of an apparatus for recording / reproducing a video signal output from the image pickup apparatus shown in FIG. The device of this example uses a conventional two-head helical scan type VTR.

A video signal obtained by normal shooting or high-speed shooting via an input terminal to which the output terminal 44 of the image pickup device is connected is subjected to FM modulation of a luminance signal in a recording signal processing circuit 54 as is well known in the above VTR. , A process of frequency-converting the carrier color signal to the reduction is performed. The adder 56 multiplexes the video signal processed by the circuit 54 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 as a pilot signal or as a pulse signal during the vertical blanking period. The video signal in which the identification signal is multiplexed is supplied to the 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.

Hereinafter, the operation of reproducing the video signal by the recording / reproducing unit 58 will be described. It is assumed that the recorded video signal is obtained by normal shooting. The switch 66 is connected to the N side in accordance with the identification signal separated by the identification signal separation circuit 62, and the video signal which is well-known signal processed by the reproduction signal processing circuit 60, that is, the luminance signal is FM demodulated, and the carrier color is transmitted. 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 64 controls the 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, an operation for reproducing a video signal captured at a high speed will be described. At this time, the video signal processed by the reproduction signal processing circuit 60 at the same time has one field composed of four small screens A, B, C and D as shown in FIG. 4 (b). In the illustrated device, the four small screens are converted into video signals that sequentially include one screen at a time in one field, and FIG.
The small screens can be sequentially displayed at the position indicated by A. That is, a reproduction signal for one field (for four small screens) is obtained in a period corresponding to four fields of the reproduction video signal, and this is output as a video signal for four fields.

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 cause the magnetic tape to run at 1/4 the speed 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, where 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 playback signal processing circuit 60 is A / D
It is input to the converter 84, digitized and input to the switch 86. The switch 86 is switched by a signal obtained by multiplying the frequency of the horizontal synchronizing signal in the reproduced signal by a multiplier 76 composed of a PLL etc., and the first half of each horizontal scanning line is stored in the 2 / n field memory 88 and the second half. 2 / n field memory 9
Supply to 0 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 is a write control circuit for the memories 88 and 90, which controls the write timing and write address, and 82 is the memories 88 and 90.
And controls the read timing and the read address. FIG. 7 shows a timing chart of writing (W) and reading (R) of the memories 88 and 90. Period T ₁ through T ₈ of Figure 7 corresponds to the period in which the reproduced signal is obtained at Figure 6 trace the trajectory T ₁ through T _8.

Memory 88, 90 writes the video signal in the period T ₃ and T _6, this write period name, half the fourth view of (b) A, B, the second half video signals corresponding C, and D Are written respectively.
In addition, by the operation of the switch 32 described above, A,
Video signals corresponding to B and D are written to C and the memory 90. In FIG. 7, A ₁ , B ₁ , C ₁ , D ₁ are video signals recorded on the track TR1, and A ₂ , B ₂ , C ₂ , D ₂ are video signals recorded on the track TR2, respectively. This corresponds to A, B, C, D in FIG. 4 (b). After tracing the trace locus T ₈ , the relationship between the track and the trace locus becomes the same as that of T ₁ again, but the period corresponding to these is marked with a dash T ₁ ′, T in FIG. ₂ ', ... Also in this case, T ₃ ′, T ₆ ′
Is written.

Period T video signal written in the memory 88 in ₃ 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
Are read out in this order. This readout timing is set to a central half field period of each one-field period, and to a central half period 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-mentioned reproduced horizontal synchronizing signal and the reproduced vertical synchronizing signal separated from the composite synchronizing signal by the vertical synchronizing circuit 74, respectively. Switch 92
Is controlled by the 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, as shown in FIG. 4 (c), the small screens A, B, C, D at the center of the output screen.
Are sequentially displayed, and a slow-motion image having an information density in the time axis direction that is four times that of a normal one can be obtained. The output of this D / A converter 94 is connected to the terminal 68 via the H side of the switch 66. Is output from.

Although two 2 / n field memories are provided in the circuit of FIG. 5, only one may be used as long as it is a random access memory. 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. 4 (c) can be used for displaying various data such as time and field number. Further, although the image is slightly rough, the image may be enlarged and displayed. n so as to satisfy the relationship of n = m ^2, by selecting the m, the aspect ratio of each image can be the same as the image in the normal shooting speed.

For electronic shutter operation, a gate pulse Φ _R (shown by a broken line in FIG. 3) may be applied before the vertical transfer pulse Φ _{V having} the frequency f ₁ to provide the electronic shutter function. Of course, a mechanical shutter or other electronic shutter may be used, or a combination with a strobe etc. may be used.

The case where n = 4 and m = 2 has been described above, but any numerical value can be adopted as long as n is a multiple of m. The image pickup device 10 may be a frame transfer type CCD or a MOS type.

In the above embodiment, the upper left part of the shooting screen (the lower right cell in the image sensor 10 in FIG. 2) is read out, but by adjusting the transfer signal to the image sensor 10, the central part of the screen and other parts are read. Can be set to read from.

〔The invention's effect〕

As can be easily understood from the above description, according to the present invention, it is possible to form a high-speed video signal that can be recorded or displayed by an ordinary video recording device or television device as it is with an extremely simple circuit configuration. In addition, it is easy to change the shooting speed and combine shooting with the normal speed.

[Brief description of drawings]

1 is a configuration block diagram of an embodiment of the present invention, FIG. 2 is a configuration diagram of an example of the image pickup device 10 of FIG. 1, and FIG. 3 is a timing chart of transfer signals of the image pickup device of FIG. FIG. 4 is a screen display diagram at each stage, FIG. 5 is a diagram showing a structural example of a device for recording and reproducing the output signal of the device of FIG. 1, and FIG. 6 is a magnetic tape on the device of FIG. 7 is a timing chart of writing and reading to and from the memory of the device of FIG. 5. 10 …… Image sensor, 12 …… Cell, 14 …… Vertical transfer CCD, 1
6 ... Gate electrode, 18 ... CCD for horizontal transfer, 20 ... Amplifier, 22 ... Output terminal, 30 ... A / D converter, 32,38 ... Switch, 34,36 ... Memory, 40 ... … D / A converter, 42 …… Signal processing circuit, 44 …… Output terminal, 48 …… Synchronous signal generation circuit

Claims (2)

(57) [Claims] 1. A device for converting an optical image on an image pickup surface into an electric signal, adding a horizontal synchronizing signal and a vertical synchronizing signal and outputting as a video signal, wherein the vertical synchronizing signal frequency is n.
Double (n is an integer of 2 or more) times the frequency of the vertical scanning signal and the horizontal synchronizing signal (m is an integer of 2 or more and a divisor of n)
Image pickup means for outputting a photoelectric conversion signal according to the horizontal scanning signal, and an output signal from the image pickup means are temporarily stored, and a total of n images of m in the horizontal direction and n / m in the vertical direction are included in one screen. A high-speed image pickup device, comprising: a conversion unit that converts and outputs a video signal. 2. A device according to claim 1, wherein n = m ² .