JPH10191133A - Video signal generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record a video image on a standard recording medium with higher timewise resolution than that of the standard. SOLUTION: A plural video image generating means like a prism 4a branches a video image of an object to generate plural video images. Then the plural video images are exposed to a photoelectric conversion element like a CCD image sensor 1 sequentially within a one-field period with a shutter like a focal plane shutter 2. Thus, the plural video images deviated timewise for one-field period are made incident on the photoelectric conversion elements and by using output of the photoelectric conversion elements a video signal is obtained so as to be recorded by a standard recording device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal generating apparatus for generating a video signal from an incident video.

[0002]

2. Description of the Related Art In order to generate a video signal of a subject, a photoelectric conversion element such as a charge-coupled image sensor (hereinafter, referred to as a CCD image sensor) is used. The image of the subject formed on the imaging surface through the lens is C
By applying a vertical synchronizing pulse to the CD image sensor, it can be output as a video signal every one field period. Video signal standards include, for example,
According to the National Television System Committee standard (hereinafter referred to as the NTSC standard), according to this standard, one field period is 1/60 second, and most of the video-related equipment is based on such a standard. Designed according to. For example, most video tape recorders and the like for recording video signals are designed to record video signals having a 1-field period of 1/60 second in accordance with the standard. If an attempt is made to analyze the motion of a subject by using a video signal generated for each 1/60 second field period, the temporal resolution is 1/60 second.

[0003]

However, there are fields in which temporal resolution of 1/60 second is insufficient for analyzing the movement of a subject. For example, in the medical field, when diagnosing vertigo, it is necessary to analyze the vibration of the patient's eyeball, but the frequency of the eyeball is 100 Hz or more. In order to analyze the motion of such a subject, it is necessary to generate and record a video signal with a temporal resolution of at least 1/200 second.

[0004] For this purpose, a video signal of a field period shorter than 1/200 second may be generated and recorded, but a recording device designed according to a standard may be used.
For example, in a video tape recorder, one field period
Video signals other than 1/60 second cannot be recorded. There is a recording device using a semiconductor memory as a recording medium specially designed for recording an image with such a high-speed shutter, but only a short-time recording is possible due to a limitation of a recording capacity.

[0005]

In order to solve the above-mentioned problems, an image signal generating apparatus according to the present invention generates a plurality of images by dividing an image of a subject by a plurality of image generating means. Then, the plurality of images are sequentially exposed to the photoelectric conversion elements within one field period by a shutter. With this device, the standard 1
When a plurality of images having a temporal shift are incident on the photoelectric conversion element during the field period, an image signal that can be recorded on a recording device of a standard can be obtained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image signal generating apparatus according to the present invention includes a plurality of image generating means for splitting an image of a subject to generate a plurality of images, a photoelectric conversion element, and an image signal generated by the plurality of image generating means. A shutter for sequentially exposing a plurality of images to the photoelectric conversion element within one field period.

Here, as the plural image generating means, any means may be used as long as it generates a plurality of images by branching the image of the subject. For example, a prism or a multi-lens may be used. it can. The prism
There are two types: one that splits the incident image into multiple images by refraction, and one that splits the incident image into multiple images by reflecting it with a half mirror provided inside, but splits the incident image into multiple images. Anything may be used as long as it causes it.

The photoelectric conversion element may be any element as long as it can input an image and output an image signal. Examples thereof include a CCD image sensor and an MO.
An S-type image sensor can be employed.

Further, all of the plurality of images generated by the plurality of image generating means may be exposed to one photoelectric conversion element, or each of the plurality of images may be provided by providing a plurality of photoelectric conversion elements. May be exposed to the corresponding photoelectric conversion elements. When a plurality of photoelectric conversion elements are provided, a plurality of shutters may be provided so as to correspond to each photoelectric conversion element.

The shutter may be, for example, a mechanically operated lens shutter or a focal plane shutter, or may be an electronically operated electronic shutter.

The image processing apparatus may further include a synthesizing means for synthesizing a one-field video signal from the video signal output from the photoelectric conversion element so that the plurality of videos are respectively displayed on a plurality of divided screens. Is also good.

According to the video signal generation device configured as described above, a plurality of videos having a time lag during one field period are exposed to the photoelectric conversion element. Therefore, by exposing a plurality of videos with a time lag during one field period of the standard by this apparatus, it is possible to obtain a video signal that can be recorded on a standard recording apparatus.

[0013]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 and FIG. 2 are diagrams conceptually showing one embodiment of a video signal generating apparatus according to the present invention. Referring to FIGS. 1 and 2, a focal plane shutter 2 is provided in front of an imaging surface 1a of a CCD image sensor 1, and a prism 4a is provided in front thereof. The prism 4a is a prism that splits an incident image into a plurality of images by refraction. The image of the eye to be inspected A enters the prism 4a through the lens B. Then, the incident image is refracted in the prism 4a and the four images A1, A2, A3, A4
Is branched to Since the image A1 among the images branched by the prism 4a corresponds to the cutout portion 2a of the focal plane shutter 2, the CCD image sensor 1
Of the other images A2 to A4
Is blocked by the focal plane shutter 2 and does not enter the imaging surface 1a.

This focal plane shutter 2
It rotates in the direction of the arrow in FIG. 2 around the rotation axis 2b at 60 Hz. Therefore, the cutout 2a of the focal plane shutter 2 comes to a position corresponding to the image A2 1/240 second after the state of FIG. The reason why the rotation speed of the focal plane shutter 2 is set to 60 Hz corresponds to the fact that the field frequency is 60 Hz in the NTSC standard, which is one of the standard standards. Therefore, one field period is 1/60 second.

FIG. 3 shows the positional relationship among the images A1 to A4, the focal plane shutter 2, and the CCD image sensor 1 when 1/240 second has elapsed from the state shown in FIG. It can be seen that the image A2 is incident on the imaging surface 1a of the CCD image sensor 1, and the other images A1, A3, A4 are blocked by the focal plane shutter 2. Thus, the focal plane shutter 2 sequentially exposes the images A1 to A4 to the CCD image sensor 1 while rotating. By the focal plane shutter 2, all of the images A1 to A4 are exposed to the CCD image sensor 1 during one field period of 1/60 second. Each of the images A1 to A4 exposed during this 1/60 second period is , Images of the eye A to be examined at different time points every 1/240 second.

FIG. 4 is a diagram showing a temporal change of the eye A to be examined every 1/240 seconds. In the control of the CCD image sensor, it is usual that charge is accumulated in one field period and a video signal is output from the CCD image sensor in the next one field period. While controlling the exposure by the focal plane shutter 2 as shown in FIGS. 1 to 3, the changing image of the eye A to be inspected is incident on the imaging surface 1a of the CCD image sensor 1 for one field period as shown in FIG. When the video signal based on the electric charges accumulated during the period is reproduced on the screen, the images A1 to A4 of the eye A at different times at 1/240 seconds appear on the screen divided into four.

FIG. 5 is a diagram showing the reproduced screen D. Images A1 to A4 of the subject's eye A are shown on each of the four divided screens D1 to D4.

As described above, by rotating the focal plane shutter 2 at 60 Hz, while controlling the exposure of the four images A1 to A4 to the CCD image sensor 1, the image signals for each one field period are transmitted to the CCD image sensor 1. From the eye A every 1/240 seconds
Of the images A1 to A4 can be signalized. Moreover,
The video signal output from the CCD image sensor 1 is 1/60
Since it complies with the standard in which seconds are defined as one field period, it can be recorded on a standard recording device, for example, a standard video tape recorder. Then, the motion of the subject's eye A vibrating at 100 Hz or more can also be analyzed from the recorded video signal later.

In the embodiment of FIGS. 1 and 2, the image of the eye A to be examined is branched into four by the prism 4a, but the number of branches is not limited to four. If the number of branches is increased, the movement of the eye A can be analyzed faster. In the embodiments of FIGS. 1 and 2, the image of the eye A to be inspected is branched by the prism 4a. However, the eye A to be inspected is split by a prism having a half mirror inside or a multi-lens composed of a plurality of lenses. May be branched.

FIG. 6 is a diagram conceptually showing another embodiment of the video signal generating apparatus according to the present invention. According to FIG. 6, four CCD image sensors 11 to 14 are provided around the prism 4b. The prism 4b includes half mirrors M1 to M3, and is a prism that reflects an incident image on the half mirrors M1 to M3 and splits the image into a plurality of images. The CCD image sensors 11 to 14 are connected to the synthesizing circuit 5. The image of the eye A to be inspected enters the prism 4b through the lens B. The image entered here is the half mirrors M1 to M3 inside the prism 4b.
Branch into four images. Then, each image after branching is incident on the imaging surface of each of the CCD image sensors 11 to 14.

The image incident on the CCD image sensor 11 is an image after being reflected once by the half mirror M2, while the image incident on the CCD image sensor 12 is reflected by the half mirror M2 and the half mirror M1.
This is an image after being reflected twice. Therefore, the image incident on the CCD image sensor 11 and the image incident on the CCD image sensor 12 are in a mutually inverted relationship. However, while the CCD image sensor 12 is a normal type CCD image sensor, the CCD image sensor 11 is a mirror inversion type CCD image sensor. Therefore, two CCD image sensors 1
The video signals output from 1 and 12 do not have an inverted relationship with each other. The CCD image sensor 13 is of a mirror inversion type, while the CCD image sensor 14 is of a normal type. Therefore, the video signals output from all the CCD image sensors 11 to 14 do not have a mutually inverted relationship.

Further, all the CCD image sensors 11
Regarding the images 14 to 14, each image incident on the imaging surface is arranged not to enter the center of the imaging surface but to enter one of the four divided imaging surfaces. ing. Therefore, when the video signals output from the respective CCD image sensors 11 to 14 are directly reproduced without passing through the synthesizing circuit 5, the video of the subject's eye A appears on one of the four divided screens. .

FIG. 7 shows each of the CCD image sensors 11-1.
4 is a diagram showing a playback screen when the video signal output from the playback device 4 is played back as it is without passing through the synthesis circuit 5. FIG. Fig. 7 (I)
Corresponds to the CCD image sensor 11,
FIG. 7 (II) corresponds to the CCD image sensor 12, FIG. 7 (III) corresponds to the CCD image sensor 13, and FIG. 7 (IV) corresponds to the CCD image sensor 14. Things. The video signal output from each of the CCD image sensors 11 to 14 is input to the synthesis circuit 5 to generate a synthesized video signal.

FIG. 8 is a view showing a reproduction screen when the composite video signal is reproduced. The image A21 of the eye A is C
The image A22 is on the CCD image sensor 12, the image A23 is on the CCD image sensor 1,
3, the image A24 corresponds to the CCD image sensor 14, respectively. As described above, each screen C is displayed on one screen D.
Four images input to the CD image sensors 11 to 14 are being reproduced.

FIG. 9 is a block diagram showing a configuration of the synthesizing circuit 5 of FIG. FIG. 10 shows the charge accumulation state of each of the CCD image sensors 11 to 14 and the delay circuits 51 to
FIG. 5 is a timing chart showing the timing at which switches 57, 58, and 59 act on video signals output from 53 and the CCD image sensor 12.

A control signal is supplied to each of the CCD image sensors 11 to 14 by an electronic shutter control circuit (not shown), thereby setting a shutter time of 1/240 second.

From the vertical synchronization pulse control circuit 55, each CC
A vertical synchronization pulse of 60 Hz is supplied to the D image sensors 11 to 14. This vertical synchronizing pulse is not supplied to all the CCD image sensors 11 to 14 at the same timing. Instead, the CCD image sensor 14, the CCD image sensor 13, the CCD image sensor 11, and the CCD image sensor 12 It is supplied at a timing shifted by 1/240 seconds. That is, the vertical synchronizing pulse control circuit 55
CC after 1/240 second after supplying vertical sync pulse to 4
A vertical synchronization pulse is supplied to the D image sensor 13, a vertical synchronization pulse is supplied to the CCD image sensor 11 1/240 seconds later, and a vertical synchronization pulse is supplied to the CCD image sensor 12 1/240 seconds later. Supply.
Then, 1/240 seconds later, a vertical synchronization pulse is supplied to the CCD image sensor 14 again. Such a cycle is repeated. As a result, each of the CCD image sensors 14, 13, 11, and 12 is sequentially exposed. Each CCD image sensor 14, 13, 1
1 and 12 output video signals using the vertical synchronization pulse as the timing of vertical synchronization.

FIGS. 10A to 10D show the charge accumulation states of the CCD image sensors 14, 13, 11, and 12. FIG. The negative pulses shown in each of FIGS. 7A to 7D are vertical synchronizing signals. As described above, since each of the CCD image sensors 11 to 14 has a shutter time of 1/240 second, the shutter time is accumulated during the first 3/4 of the 1/60 second field period. The charge is discharged, and
And outputs a video signal based on the electric charge accumulated during the period.
FIGS. 10A to 10D show only the charge accumulation state during the subsequent ４, and the accumulation state during the first ／ is omitted. Also, for each of FIGS.
Only the charge accumulation state for a certain field period is shown, and only the vertical synchronization signal is shown for the other field periods. This is for the sake of simplicity.
Actually, charges are accumulated in other field periods. For example, FIG. 10A is a diagram showing a charge accumulation state of the CCD image sensor 14, and a video signal based on the charge accumulated in the field period a1 is output during the next field period a2. Is done. In addition,
FIG. 10B shows the CCD image sensor 13.
FIG. 10C shows the CCD image sensor 11.
FIG. 10D illustrates the CCD image sensor 12.

Referring to FIG. 9, video signals from CCD image sensors 14, 13, and 11 other than CCD image sensor 12 are input to delay circuits 51, 52, and 53, respectively.
It is output here after a certain delay. Here, a delay time of 3/240 seconds is set for the delay circuit 51, 2/240 seconds for the delay circuit 52, and 1/240 seconds for the delay circuit 53. Thereby, each delay circuit 51
53 and the video signal output from the CCD image sensor 12 are synchronized. The timing generator 56 supplies a pulse for measuring the delay timing to each of the delay circuits 51 to 53.

Next, for these synchronized video signals,
The switches 57, 58, and 59 operate, and the respective video signals are combined and supplied to the output terminal 60. The switch 57 and the switch 58 are linked with each other, and are controlled by a switch control circuit (not shown) so as to be switched every half of the horizontal scanning period. The switch 59 is controlled by a switch control circuit (not shown) so as to be switched every half of one field period, that is, every 1/120 second. The switches 57 and 58 are connected at the beginning of the horizontal scanning period.
The period of / 2 is switched to the terminals 57a and 58a, and the subsequent period of 1/2 is switched to the terminals 57b and 58b. The switch 59 switches to the terminal 59a during the first half of one field period, and switches to the terminal 59b during the latter half.

FIGS. 10 (e) to 10 (h) show each delay circuit 51.
53, and which part of the video signal is effectively supplied to the output terminal 60 as a result of the operation of the switches 57, 58, and 59 on the video signal output from the CCD image sensor 12. is there. Each figure (e) ~
The negative pulse shown in (h) is a vertical synchronization signal. 10E shows the delay circuit 51, FIG. 10F shows the delay circuit 52, FIG. 10G shows the delay circuit 53, and FIG.
Corresponds to the CCD image sensor 12, respectively. For example, in the NTSC standard, which is one of the standards, a horizontal scan of 262.5 is performed in one field period, but in FIG. 10E to FIG. It is described that eight horizontal scans are performed.

For example, FIG. 10E shows that only the portion of the video signal output from the delay circuit 51 supplied to the output terminal 60 is inverted U under the action of the switches 57 and 59.
It is represented by a character signal curve. Only the signal of FIG. 10E reproduces the video A24 in the upper left portion of the four-divided screen of FIG. Similarly, the video A23 in the upper right portion of the four-divided screen in FIG. 8 is reproduced only by the signal in FIG. 10 (f). Also, the video A21 of the lower left part of the four-divided screen of FIG. 8 is reproduced only by the signal of FIG. 10G, and only the signal of FIG.
Video A2 of the lower right part of the four divided screens in FIG.
2 is played.

The output terminal 60 shown in FIG.
A signal in which all the signals of (e) to (h) are combined is supplied. This synthesized signal is a video signal that reproduces the entire screen of FIG. Since the synthesized video signal is a signal including one vertical synchronizing signal in one field period of the standard, it can be recorded on a standard recording device, for example, a standard video tape recorder.

In the above embodiment, a shutter time of 1/240 second is set by the electronic shutter. However, the shutter time is not limited to this, and may be shorter, or may be longer, for example, The time may be 1/60 second, which is the same time as one field period.

Also, in the above embodiment, FIGS.
The video signal was obtained by synthesizing the signals of (h). The video signals output from the CCD image sensors 11 to 14 were respectively transmitted to the four video tape recorders without passing through a delay circuit or a switch. It may be recorded. Even in this case, it is possible to record a video every 1/240 second, though it is recorded on a plurality of recording devices.

FIGS. 11 and 12 are diagrams conceptually showing still another embodiment of the video signal generating apparatus according to the present invention. This uses a multi-lens 40 as a plurality of image generating means, and each lens 41 to 44 constituting the multi-lens 40 is used.
The image of the subject's eye A that has passed through the lens is incident on CCD image sensors 21 to 24 provided corresponding to the respective lenses 41 to 44. However, focal plane shutters 31 to 34 that rotate at 60 Hz are provided in front of the CCD image sensors 21 to 24, respectively.
Images are sequentially exposed to the CD image sensors 21 to 24. The video signals output from each of the CCD image sensors 21 to 24 are input to the synthesis circuit 6. Note that FIG. 11 shows only two lenses, two CCD image sensors, and two focal plane shutters, because FIG. 11 is a side view, and the other two lenses are hidden. .

FIG. 13 shows the structure of the synthesizing circuit 6 of FIG. Here, the CCD image sensors 21 to 2
From the four video signals, video signals are synthesized on one screen such that the video of the four eyes A to be examined, which is temporally shifted by 1/240 seconds, is reproduced. As in the device of FIG.
And the switch 58 are linked with each other, and are controlled by a switch control circuit (not shown) so as to be switched every half of the horizontal scanning period. The switch 59 is set to a half of one field period by a switch control circuit (not shown).
The control is performed so as to be switched every time, that is, every 1/120 second. The switches 57 and 58 are connected to the terminals 57a and 58a for the first half of the horizontal scanning period,
Is switched to the terminals 57b and 58b. The switch 59 is connected to the terminal 59a during the first half of the one-field period, and is connected to the terminal 59b during the last half.
Switch to the side.

For each of the CCD image sensors 21 to 24, a vertical synchronizing pulse control circuit (not shown)
Are supplied. Unlike the apparatus of FIG. 9, this vertical synchronization pulse is supplied to all the CCD image sensors 21 to 24 at the same timing. Therefore, there is no need to provide a delay circuit as shown in FIG.

The apparatus configured as shown in FIGS. 11 to 13 can also provide a video signal that reproduces a screen similar to the screen shown in FIG. Further, since the synthesized video signal is a signal including one vertical synchronization signal in one field period, it can be recorded on an existing standard recording device, for example, a standard video tape recorder or the like.

In all of the above embodiments, the video signal generated by the video signal generation device may be wirelessly transmitted to an external recording device via a wireless device and recorded.

[0042]

According to the video signal generating apparatus of the present invention, it is possible to expose the video at a plurality of time points to the photoelectric conversion element within one field period of the standard. Therefore, if the video signal output from the photoelectric conversion element is used, a video can be recorded on a standard recording medium with a higher temporal resolution than the standard.

Further, it is preferable that the image processing apparatus further comprises a synthesizing means for synthesizing a video signal of one field from the video signal output from the photoelectric conversion element so that the plurality of videos are respectively displayed on a plurality of divided screens. In particular, it is possible to obtain a video signal of a standard such that each video sequentially incident on a plurality of photoelectric conversion elements in one field period is reproduced on one screen.

[Brief description of the drawings]

FIG. 1 is a side view conceptually showing one embodiment of a video signal generation device.

FIG. 2 is an oblique view of the video signal generation device of FIG. 1;

FIG. 3 is a perspective view of the video signal generation device when 1/240 second has elapsed from the state of FIG. 2;

FIG. 4 is a diagram showing a temporal change of an eye to be examined every 1/240 seconds.

FIG. 5 is a diagram showing a playback screen.

FIG. 6 is a side view conceptually showing another embodiment of the video signal generation device.

FIG. 7 is a diagram showing a reproduction screen when a video signal output from each CCD image sensor is reproduced as it is without passing through a combining circuit. FIG. 7 (I) is a CCD image sensor 1
7 is a diagram corresponding to the CCD image sensor 12, FIG. 7 (III) is a diagram corresponding to the CCD image sensor 13, and FIG. 7 (IV) is a diagram corresponding to the CCD image sensor. FIG. 3 is a diagram corresponding to a sensor 14.

FIG. 8 is a diagram showing a playback screen when a composite video signal is played back.

FIG. 9 is a diagram illustrating a configuration of a synthesis circuit.

FIG. 10 is a timing chart showing a charge accumulation state of each CCD image sensor and an operation state of a switch for a video signal. FIGS. 10A to 10D are diagrams showing the charge accumulation state of each CCD image sensor. FIG.
(E)-(h) is a figure which shows the operation | movement state of the switch with respect to the video signal output from each delay circuit and CCD image sensor 12. FIG.

FIG. 11 is a side view conceptually showing still another embodiment of the video signal generation device.

FIG. 12 is a perspective view of a part of the video signal generation device of FIG. 11;

FIG. 13 is a diagram illustrating a configuration of a synthesis circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CCD image sensor 2 ... Focal plane shutter 4a, 4b ... Prism 5 ... Synthesis circuit 6 ... Synthesis circuit 11,12,13,14 ... CCD image sensor 21,22,23,24 ... CCD image sensor 31,32,33 Reference numeral 34: Focal plane shutter 40: Multi-lens A: Eye to be inspected B: Lens

Claims (3)

[Claims] 1. A plurality of image generating means for generating a plurality of images by branching an image of a subject, a photoelectric conversion element, and a plurality of images generated by the plurality of image generating means are sequentially transmitted within one field period. A video signal generation device comprising: a shutter exposed to the photoelectric conversion element. 2. The video signal generating device according to claim 1, wherein said plurality of video generating means is a prism or a multi-lens. 3. A synthesizing means for synthesizing a video signal of one field from the video signal output from the photoelectric conversion element so that the plurality of videos are respectively displayed on a plurality of divided screens. Item 3. The video signal generation device according to Item 1 or 2.