JPH04114268U - high speed imaging camera - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to provide an inexpensive high-speed imaging camera. [Structure] Incident light is separated into red, green, and blue by a dichroic prism 4, and is made incident on an R image sensor 1, a G image sensor 2, and a B image sensor 3, which are CCD image sensors. First, second, and third drivers 5, 6, and 7 are connected to each image sensor 1, 2, and 3, respectively. Driver 5, 6,
7, a sweep pulse and a transfer pulse having a period of T and a phase shift of ΔT (Δ<1/3T) are transmitted to the imaging elements 1, 2, and 3.
Output each. The image sensors 1, 2, and 3 output charges accumulated during the period from when the sweep pulse is input until when the transfer pulse is input as an image signal. Here, the phases of the sweep pulses outputted by the drivers 5, 6, and 7 are shifted from each other by 1/3T. Therefore, the image sensor 1,
2 and 3 output an image signal every 1/3T.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a high-speed imaging camera.

0002

[Conventional technology and its problems]

Generally, when capturing instantaneous images of a subject that is moving or changing at high speed. A high-speed imaging camera is used. However, conventional high-speed imaging cameras have It is expensive because it has a complicated structure and requires mechanisms such as a high-speed shutter. There was a problem.

0003

[Means to solve the problem]

This idea was made in consideration of the above circumstances, and it uses multiple image sensors and one An optical system that branches incident light and makes each branched light enter each image sensor, and each image sensor and a shutter mechanism that sequentially exposes the light at substantially different times. It is said that

0004

[Effect]

The shutter mechanism sequentially exposes each image sensor at different times. therefore, Each image sensor outputs image signals of the subject at different times.

[0005]

【Example】

First, before explaining the practical examples of this invention, let us first explain the idea that led to this invention. In other words, the inventor believes that color television cameras can be used for red, green, and blue (hereinafter referred to as red, green, and blue). , are called R, G, and B, respectively. ). Normally, these three image sensors image the subject at the same time, but each I was surprised to find that high-speed imaging can be achieved by slightly shifting the timing of imaging. I've reached it. If you do this, there is no need for a high-speed shutter, etc., so the color - By modifying TV cameras, it is possible to manufacture high-speed imaging cameras at low cost. I have come up with something that can be done.

[0006] Hereinafter, embodiments of this invention will be described with reference to FIGS. 1 to 5. An embodiment of this invention is shown in FIGS. 1 to 3. The high-speed imaging camera of this example It is a modified version of a commercially available color television camera, and as shown in Figure 1, the red Three image sensors 1, 2 for color (for R), for green (for G), and for blue (for B), It has 3. In this case, the image sensors 1, 2, and 3 are CCDs (Charge-C An image sensor (upled device) is used. Image sensor 1, 2, 3 An optical system having a dichroic prism 4 is arranged in front of the dichroic prism 4 . Thailand As shown in FIG. 2, the chroic prism 4 includes three prisms 4a, 4b, 4c. It separates the incident light into red, green and blue, and images each separated light. The light is made incident on elements 1, 2, and 3, respectively.

[0007] Furthermore, this high-speed imaging camera includes first to third drivers 5, 6, and 7 in order to shift the actual exposure timing of each of the imaging elements 1, 2, and 3. The first driver 5 outputs a sweep pulse P ₁ and a transfer pulse P ₂ shown in FIG. 3 to the R image sensor 1 based on the number of clock signals input from the clock signal generator 8. The sweep pulse P ₁ and the transfer pulse P ₂ have the same period T. In order to comply with the NTSC system, the period T is set to 1/60 seconds when interlaced scanning is performed in image sensors 1, 2, and 3, and 1/30 seconds when non-interlaced scanning is performed. . Further, the phase of the transfer pulse P ₂ is delayed by ΔT with respect to the sweep pulse P ₁ . The phase difference ΔT is made smaller than 1/3·T.

[0008] When the sweep pulse P ₁ is output from the first driver 5 to the image sensor 1, the image sensor 1 sweeps out all the image charges accumulated up to that point. The swept-out image charge is never used as an image signal. When the transfer pulse P ₂ is output after the sweep pulse P ₁ is output, the image sensor 1 outputs the image charge accumulated during that time (ΔT) to the matrix circuit 9 described later as an image signal. As is clear from this point, the incident light that is actually used out of the incident light that is converted into charges by the image sensor 1 is the time from when the sweep pulse P ₁ is output to when the transfer pulse P ₂ is output. Only the light incident on ΔT. In other words, the image sensor 1 is substantially exposed for the time ΔT by the first driver 5, and the first driver 5 constitutes a kind of shutter mechanism.

The second and third drivers 6 and 7 send sweeping pulses P _{3 and} P ₅ and transfer pulses P ₄ and P ₆ similar to the pulses P ₁ and P 2 to the G image sensor 2 and the B image sensor. Output each to 3. However, the phase of the sweep pulse P ₃ is delayed by 1/3·T with respect to the sweep pulse P ₁ , and the phase of the sweep pulse P ₅ is delayed by 2/3·T with respect to the sweep pulse P ₁ . . Therefore, compared to the exposure time of the R image sensor 1, the exposure time of the G image sensor 2 is delayed by 1/3·T, and the exposure time of the B image sensor 3 is delayed by 2/3·T. Become.

The image sensors 1 , 2 , and 3 output image charges, that is, image signals to the matrix circuit 9 . In this case, the image sensors 1, 2, and 3 simultaneously output pulses based on the pulses (different from the pulses _P1 to _P6 described above) output from the respective drivers 5, 6, and 7. The matrix circuit 9 generates a luminance signal (Y signal) indicating brightness and a color difference signal (RY signal and B-Y signal) indicating color tone from the red, green, and blue image signals, and uses the normal What the color television camera has is used as is. Note that the luminance signal and the color difference signal are converted into, for example, a video signal by the encoder 10 and output.

[0011] In the above-mentioned high-speed imaging camera, the three imaging elements 1, 2, and 3 are substantially Since the exposure is performed by shifting the frame sampling of each image sensor 1, 2, and 3, Images of the subject are obtained at a period of 1/3 of the period. In other words, a constant period Three times as many images can be obtained. Therefore, high-speed imaging becomes possible. Moreover, As shown in this example, by modifying a conventional color TV, high-speed shooting can be achieved. An image camera can be manufactured easily and inexpensively.

0012 Note that this invention is not limited to the above-mentioned embodiments, and does not depart from the gist of the invention. It can be changed as appropriate within a certain range. For example, in the above embodiment, it consists of three prisms 4a, 4b, 4c. By using the dichroic prism 4, the light enters the image sensors 1, 2, and 3. As shown in FIG. 4, two prisms 14a are used to separate the light into red, green, and blue. , 14b is used to simply branch the incident light. The branched light may be made to enter each image sensor 1, 2, and 3. Also, Instead of using three image elements, as shown in FIG. Only 2 may be used. In this case, one prism is used to split the incident light. It is sufficient to use only the optical system 24.

[0013] In addition, in the above embodiment, the charges accumulated in each image sensor 1, 2, and 3 are The effective timing of exposure is determined by periodically sweeping and outputting. A mechanical shutter is provided between the dichroic prism 4 and each image sensor 1, 2, and 3. A mechanism may also be installed. In this case, each image capturing by each shutter mechanism The exposure timings of elements 1, 2, and 3 are staggered. By doing this, each Even if the shutter speed of the shutter mechanism is slow, high-speed imaging becomes possible.

[0014]

[Effect of the idea]

As explained above, the high-speed imaging camera of this invention uses multiple imaging elements. Because the exposure times are staggered, high-speed imaging is possible. Of course, since there is no need for a high-speed shutter mechanism, the mechanism is simpler and more compact. The effect is that it can be manufactured easily and at low cost.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of this invention.

FIG. 2 is a diagram showing a dichroic prism used in the embodiment shown in FIG. 1.

FIG. 3 is a diagram showing the relationship between pulses output from the first, second, and third drivers to each image sensor.

FIG. 4 is a diagram showing another embodiment of a prism for splitting incident light.

FIG. 5 is a diagram showing another embodiment of a prism for splitting incident light.

[Explanation of symbols]

1 Image sensor 2 Image sensor 3 Image sensor 4 Dichroic prism (optical system) 5 First driver (shutter mechanism) 6 Second driver (shutter mechanism) 7 Third driver (shutter mechanism) 14 Branch prism (optical system) 24 Prism (optical system)

Claims (1)

[Scope of utility model registration request] 1. A plurality of image sensors, an optical system that branches one incident light and makes each branched light incident on each image sensor, and a shutter mechanism that sequentially exposes each image sensor at substantially different times. A high-speed imaging camera characterized by: