JP2008005273A - Trigger signal output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a trigger signal output device capable of surely detecting the occurrence of a high-speed phenomenon to be photographed by a high-speed photographing devicepromptly and outputting a trigger signal. <P>SOLUTION: An XY address type solid-state image pickup element such as a CMOS image sensor is used, and only one predetermined light receiving element among a plurality of light receiving elements arranged like a matrix in the solid-state image pickup element is made to output a light reception signal. Thus, light reception signals are continuously output only from the light receiving element. When the value of the light reception signal satisfies a predetermined reference, it is judged that a subject whose significant luminance change has been generated exists in a photographic place, and a trigger signal is output. The light reception signals are continuously output from the single light receiving element so that any delay can be prevented from being generated in a reading time, and that the trigger signal can be output promptly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for detecting the start of a phenomenon and outputting a trigger signal that instructs the imaging apparatus to start imaging when imaging a high-speed phenomenon such as destruction, explosion, or combustion.

  2. Description of the Related Art Conventionally, high-speed imaging devices for continuously imaging high-speed phenomena such as explosion, destruction, combustion, collision, and discharge have been developed (see, for example, Non-Patent Documents 1 and 2). At present, it is possible to shoot at a very high speed of 1 million images / second with a high-speed imaging device.

  In a high-speed photographing apparatus, the number of images that can be photographed is limited in exchange for performing photographing at high speed (for example, about 100 images at the maximum), so that photographing can be performed only for a short time. For this reason, it is necessary to obtain a trigger signal synchronized with the occurrence of a phenomenon intended for photographing and to determine an appropriate timing for starting photographing. The trigger signal is usually output by a trigger sensor such as a contact sensor, a position sensor, a vibration sensor, or a pressure sensor.

“Developed a super-high-speed video camera with a shooting speed of 1 million frames / second (press release dated September 27, 2001”, [online], Shimadzu Corporation, [searched May 20, 2006], Internet, < URL: http://www.shimadzu.co.jp/news/press/010927.html> Hiromasa Maruno, Yasushi Kondo, Goji Eto, “High-speed video camera using pixel peripheral recording image sensor”, Applied Optics 2002 Vol.2 No.12 p.5-8, December 10, 2002

  There is no problem with the conventional configuration as long as the trigger sensor can obtain an effective trigger signal, but it may be difficult to obtain an effective trigger signal with the trigger sensor depending on the phenomenon. Therefore, it is conceivable to detect the movement of a phenomenon from a moving image (image) obtained by photographing a certain location, thereby generating a trigger signal. Actually, in a low-speed photographing device such as a surveillance camera, a device that detects a movement of a subject from a luminance change of a photographed image and outputs a trigger signal (trigger signal output image photographing device) has been developed and put into practical use. .

  However, when applying the trigger signal output image capturing device to a high-speed image capturing device, the lack of time resolution becomes a problem. (For example, when the frame rate is 30 fps, one pixel is imaged only once every 33 ms.) If the time resolution is low, the detection of the occurrence of the phenomenon may be delayed and the detection may not be performed.

  The present invention has been made in view of such problems, and in a trigger signal output device that detects the movement of a phenomenon from an image luminance change in a captured image, a high-speed imaging device that performs imaging at an extremely high frame rate The main purpose is to improve the time resolution to the extent applicable to the above.

The trigger signal output device according to the present invention, which has been made to solve the above problems,
A solid-state imaging device configured such that only a predetermined one of the plurality of light receiving elements arranged in a matrix outputs a light reception signal;
A trigger output unit that outputs a trigger signal when a value of the light reception signal satisfies a predetermined criterion;
It is characterized by providing.

  In addition, the trigger signal output device of the present invention may further include a light receiving element setting unit that sets one light receiving element that outputs a light reception signal in the solid-state imaging device.

  According to the trigger signal output device of the present invention, a light receiving signal such as a signal voltage is constantly output from one light receiving element, and the trigger output unit trigger signal when the value of the light receiving signal satisfies a predetermined reference. Is output. As a result, the trigger signal is output without delay when the subject appears at the shooting location. Therefore, the problem that the occurrence of the phenomenon cannot be detected well because the time resolution of the trigger signal output device using the photographed image is insufficient, which is a problem that has existed in the past when detecting the phenomenon of the photographing object, is solved. Is done.

  Furthermore, by providing a configuration including a light receiving element setting unit, it is possible to more easily specify and set a light receiving element that is a trigger signal output target.

  The trigger signal output device according to the present invention captures a phenomenon (subject) to be photographed using a high-speed photographing device by a solid-state imaging device included in the trigger signal output device of the present invention, and luminance generated by the occurrence of the phenomenon. A trigger signal is output based on the change. The trigger signal output device of the present invention is particularly suitable for high-speed imaging devices, but is not limited to high-speed imaging devices, and is used as a trigger signal output device for any other imaging device. It is possible.

An example of usage of the trigger signal output device according to the present invention is shown in FIG. It is preferable that the trigger signal output device and the high-speed imaging device capture images of almost the same location, but the trigger signal output device and the high-speed imaging device may have slightly different imaging angles with respect to the imaging location. . By aligning the shooting locations of both, the subject can be reliably shot simply by starting shooting as soon as the high-speed shooting device receives the trigger signal.
When the moving speed of the subject is known, the shooting locations of the trigger signal output device and the high-speed shooting device may be different. In this case, after the trigger signal output device detects the subject, the trigger signal may be output after a lapse of time when the subject is predicted to enter the shooting location of the high-speed imaging device.

  The trigger signal output device according to the present invention includes a solid-state imaging device 1 that performs imaging of an imaging location via a lens system, and a trigger output unit 3 that receives a signal output from the solid-state imaging device 1 and outputs a trigger signal. Become. In addition, a console having a display unit and an input unit for performing various settings including designation of a light receiving element is provided.

The solid-state imaging device 1 of the present invention is a solid-state imaging device that can arbitrarily designate a light-receiving element from which a light-receiving signal is extracted. For this purpose, it is preferable to use a so-called XY address type (for example, CMOS type element or MOS type element) solid-state imaging element. Then, instead of reading out signals from all the light receiving elements of the solid-state imaging device 1, a light receiving signal is always output from only one light receiving element designated in advance (referred to as the designated light receiving element 2 in the present invention). To do.
FIG. 3 shows a configuration of a readout circuit of the designated light receiving element 2 when a CMOS type element is used as the solid-state imaging device 1 as an example. In FIG. 3, the readout circuit is drawn for four light receiving elements. Of these, the lower left light receiving element is set as the designated light receiving element 2, and only the designated light receiving element 2 is connected to the output circuit of the solid-state imaging element. ing. Accordingly, in the present invention, only the light reception signal of the designated light receiving element 2 is always output from the solid-state imaging device 1.
The received light signal may be any signal as long as it can represent luminance, such as voltage, current, and charge.

  In the solid-state imaging device 1 of the present invention, when the number of pixels is large, the detection area per pixel becomes narrow, but a minute change can be detected and the sensitivity is high. On the other hand, when the number of pixels is small, the detection area becomes wide but the sensitivity is low. Therefore, it is preferable to appropriately select the solid-state imaging device in accordance with the characteristics of the phenomenon to be photographed.

  A predetermined reference is set in the trigger output unit 3 in advance, and a trigger signal is output when the received light signal output from the designated light receiving element 2 satisfies the reference. For example, the trigger output unit 3 may be configured by combining a window comparator and a trigger output circuit. The window comparator is a circuit that checks whether or not an input voltage value is within a set range. When the subject to be photographed appears in the photographing location, a change in luminance occurs, and when the signal voltage value output from the designated light receiving element 2 is out of the preset range, the window comparator outputs a trigger output to the trigger output circuit. The trigger output circuit generates and outputs a trigger signal.

  Depending on the mode of use of the present invention, the designation of the designated light receiving element 2 and the designation of the reference value for outputting the trigger signal are relatively frequent. Therefore, it is preferable that these designations can be operated by a console (usually a personal computer or a dedicated computer).

  When the designated light receiving element 2 is specified using the console, as shown in the circuit diagram of FIG. 4, the traveling direction of the light receiving signal output from the solid-state imaging element is set to either the video output circuit side or the trigger output unit side. It is preferable to have a configuration including a signal switch that can be selected.

In order to display a photographed image of the entire solid-state imaging device 1 on the display of the console, the signal switch is switched so that the light reception signal output from the solid-state imaging device flows to the video output circuit. At the same time, the circuit of the solid-state image sensor 1 is set so that light reception signals are output from all the elements of the solid-state image sensor 1. By doing so, the received light signal is output as a video through a video output circuit, and a captured image of the entire solid-state imaging device 1 is displayed on the display of the console. When the user designates a light receiving element to be set as a detection location on the display by using an input unit such as a mouse or a keyboard, the circuit of the solid-state imaging device 1 is set so that the light receiving element corresponding to the location becomes the designated light receiving device 2. To be set. That is, it is set so that a light reception signal is always output only from the designated light receiving element 2. At this time, the signal switch is switched so that the received light signal flows to the trigger output unit side as shown in FIG.
In the present invention, a configuration for setting the designated light receiving element 2 as described above is referred to as a light receiving element setting unit. The light receiving element setting unit is realized by cooperation between a function realized by software in the console and a circuit setting in the solid-state imaging element 1.

Further, when the setting of the reference value is changed using the console, the reference value in the trigger output unit 3 (for example, the reference value in the window comparator) is set.
Thus, the work efficiency is improved by adopting a configuration in which various settings can be made from the console.

  Although the embodiment of the trigger signal output device according to the present invention has been described above, it is obvious that the above is only an example, and modifications and improvements may be appropriately made within the spirit of the present invention. .

The figure which shows the usage example of the trigger signal output device which concerns on this invention. The schematic diagram of the configuration of the trigger signal output device according to the present invention. The figure which shows the circuit example of the solid-state image sensor in the trigger signal output device which concerns on this invention. The circuit block diagram of a signal switch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Solid-state image sensor 2 ... Designated light receiving element 3 ... Trigger output part

Claims (2)

A trigger signal output device for outputting a trigger signal to an imaging device,
A solid-state imaging device configured such that only a predetermined one of the plurality of light receiving elements arranged in a matrix outputs a light reception signal;
A trigger output unit that outputs a trigger signal when a value of the light reception signal satisfies a predetermined criterion;
A trigger signal output device comprising: Furthermore,
The trigger signal output device according to claim 1, further comprising: a light receiving element setting unit that sets one light receiving element that outputs a light reception signal in the solid-state imaging element.

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