JP2001242503A - Exposure controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pick up an image at constant brightness by adjusting an exposure amount for an object to be picked up whose hue and density are changing while keeping an image pickup condition constant but without using a complicated control mechanism for an illuminating device. SOLUTION: As for an exposure controller equipped with the illuminating device 1 and an image pickup device 6 with a shutter and for controlling the exposure amount for the object to be picked up 9 whose hue and density are changing, the quantity of light emitted by the illuminating device 1 is made variable from start to finish and the controller is provided with an inputting means 4 for previously inputting information on the hue and the density of the object 9 to be picked up, and the exposure amount is controlled by changing a time interval from starting emitting the light to the timing of starting a shutter operation on the basis of the information inputted by the inputting means 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an exposure control device in an image pickup device with a shutter.

[0002]

2. Description of the Related Art In a conventional apparatus, when the color or shade of an object to be imaged changes (even if the amount of exposure to the object is the same, a dark object, for example, a blue object, appears dark and becomes dark from the image pickup apparatus). The video signal level is low, while the color tone is light, for example, a yellow object is bright and the video signal level is high.) As a method of adjusting the exposure amount, the shutter speed of the imaging device is varied, or the lens has The adjustment is performed by adjusting the amount of incident light by a diaphragm mechanism or by adjusting the amount of light emitted from the illumination device. For example, C
In an electronic shutter such as a CD camera, there are a shutter that controls the opening time according to the amount of incident light, and a diaphragm that adjusts the aperture diameter of the imaging device according to the amount of incident light.

[0003] Further, in light emission amount adjustment of a lighting device, Japanese Patent Laid-Open No.
The control of the exposure amount is performed by controlling the opening time of the illumination device as described in JP-A-195586, or a plurality of times in one exposure as described in JP-A-7-13233. In a flash-type lighting device that emits light, the amount of exposure is controlled by varying the duty ratio at the time of light emission.

[0004]

However, in the above-described conventional exposure control method, when an image of a moving object is captured, the amount of blur of the captured image changes in a method in which the shutter speed of the image capturing apparatus is varied. In the adjustment of the amount of incident light using a diaphragm mechanism such as a lens, the depth of field changes, and it is difficult to perform imaging while adjusting the exposure amount under a constant imaging condition.

In the method of varying the light amount of the illumination device, although the imaging conditions can be kept constant, the illumination device needs a control mechanism of the light emission amount, which is inconvenient in terms of simplicity of the device as compared with a normal illumination device. was there.

According to the present invention, a constant brightness can be obtained by adjusting the exposure amount of an object to be imaged whose color and shade change, while keeping the imaging conditions constant and without using a complicated control mechanism for the illumination device. An object of the present invention is to provide an exposure control device that performs imaging by using a camera.

[0007]

In order to solve the above problems, the present invention employs the following configuration.

An exposure control device comprising an illumination device and an imaging device with a shutter for controlling an exposure amount of an imaging object having a change in color tone and shading, wherein the illumination device is provided between a start of light emission and an end of light emission. An exposure control device for controlling the exposure amount by changing a time interval from the start of the emission to the operation start timing of the shutter.

[0009] The exposure control device may further include an input unit for inputting information on a color and a shade of the object to be imaged in advance, and the time interval may be changed based on information from the input unit.

[0010] An exposure control device including an illumination device and an imaging device with a shutter for controlling an exposure amount of an object to be imaged having a change in color tone and shading, wherein the illumination device operates from the start of light emission to the end of light emission. The pre-imaging is performed by one or more flashes according to a predetermined light emission start timing and a predetermined shutter operation timing, and the imaging object obtained by the preliminary imaging is obtained. Calculating the required amount of exposure based on the video signal level of the exposure, and controlling the amount of exposure by changing the time interval from the start of the light emission to the operation start timing of the shutter based on the calculated required amount of exposure. Control device.

An exposure control device comprising an illumination device and an imaging device with a shutter for controlling an exposure amount of an object to be imaged having a change in color tone and shading, wherein the illumination device operates from the start of light emission to the end of light emission The amount of light emission changes between the light-emitting devices, and the image-capturing device captures a plurality of images for one light-emission by the illumination device. An exposure control device that controls an exposure amount by selecting a video signal closest to an expected video signal level from video signals.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an exposure control apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram illustrating a configuration of an exposure control device according to a first embodiment of the present invention, and FIG. 2 is a diagram illustrating a relationship between a change in light emission amount from the start of light emission to the end of light emission and shutter operation timing. . FIG. 3 is a diagram showing a configuration of an exposure control device according to a second embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing a configuration of an exposure control device according to the embodiment.

Here, 1 is an illumination device, 2 is a light emission timing control circuit, 3 is a sensor, 4 is a color density information input device, 5 is a shutter timing control circuit, 6 is an imaging device with a shutter, 7 is an image recognition device, 8 is a conveying device, 9
Denotes an imaging object, 10 denotes a required exposure amount calculation circuit, and 11 denotes a video signal selection circuit.

In FIG. 1, the light-emission timing control circuit 2 and the shutter-timing control circuit 5 indicate that the image pickup object 9 carried by the conveyance device 8 has reached a certain point with respect to the image pickup device 6 with a shutter by the sensor 3. Output. The shutter timing control circuit 5 delays (delays) the time required for the imaging target 9 to reach the imaging device 6 with the shutter, which is determined in advance, based on the distance between the sensor 3 and the imaging device 6 with the shutter and the speed of the transport device 8. ) To output a shutter signal to the imaging device 6 with a shutter.

The light emission timing control circuit 2 receives information on the color and shade of the object 9 from the color tone information input device 4 (for example, even if the amount of exposure to the object is the same, For example, in the case of a blue object, the image signal level from the image pickup device is low and the image signal level from the imaging device is low.On the other hand, in the case of a light object such as a yellow object, the image signal level is high and the image signal level is high. Since the exposure amount is different, the color density information input device 4
Is provided from a host device with information on the color and shade of the imaged object that is being conveyed), the known shutter speed of the imaging device 6 with a shutter, and the light emission amount from the start of light emission to the end of light emission in FIG. From the relationship of the change, the light emission timing that becomes the necessary exposure amount is calculated, and the light emission timing is output to the illumination device 1.

More specifically, when the object to be imaged is blue, it becomes dark and the video signal level becomes low. Therefore, in order to solve this problem, the light emission timing control circuit 2
It is given from the input device 4 that it is blue,
A known shutter speed and a light emission amount relationship diagram shown in FIG.
The light emission start timing of the illuminating device 1 is to be controlled so as to obtain the necessary exposure amount from the above. In the case of blue, the control is performed such that the timing is earlier than that of yellow.

Accordingly, the imaging device 6 with a shutter is provided.
Can suppress the variation of the output video signal level due to the hue and shading of the imaging object 9, and can obtain an image with stable brightness on the image recognition device 7.

FIG. 3 shows an exposure control apparatus according to a second embodiment of the present invention. This embodiment corresponds to the tint information input apparatus 4 in the first embodiment described above, and calculates a necessary exposure amount. A circuit 10 is provided.

The fact that the imaging object 9 carried by the transport device 8 has reached a certain point with respect to the imaging device with shutter 6 by the sensor 3 is output to the light emission timing control circuit 2 and the shutter timing control circuit 5. The shutter timing control circuit 5 is, as in the first embodiment,
The delay until the imaging object 9 reaches the imaging device with shutter 6 is delayed (delayed), and a shutter signal for preliminary imaging is output to the imaging device with shutter 1 or more times. The light emission timing control circuit 2 also detects a signal from the sensor 3 and outputs the signal to the lighting device 1 at a light emission timing which is a preset reference of the exposure amount. That is, since the hue and the shading of the object to be transported are not known in advance, the illumination device is caused to emit light at an appropriate timing set in advance to perform preliminary imaging.

Next, the image pickup device 6 with the shutter feeds back the video signal which is the output thereof to the necessary exposure amount calculating circuit 10, and in this circuit 10, the relationship between the obtained necessary exposure amount, the time and the light emission amount in FIG. The light emission timing control circuit 2 and the shutter control circuit 5 calculate the required exposure amount (specifically, if the object to be conveyed is blue, the video signal from the imaging device 6 is at a low level, It is calculated that the exposure amount E shown in FIG. 2 needs to be increased in order to obtain the adjusted brightness), the light emission start timing is output to the illumination device 1, and the shutter operation is started to the shuttered imaging device 6. The timing is output as a shutter signal for actual imaging. Here, the light emission start timing and the shutter start timing are controlled simultaneously, but only one of them may be controlled to change the exposure amount.

At this time, the shutter signal for preliminary imaging and the shutter signal for actual imaging one or more times are successively outputted, and during that period, the imaging object is extremely negligible compared to the time required for the imaging object to move by the transport device. It is small. As an example, the light emission time shown in FIG. 2 is 1/1000 second and the shutter speed is 1/10000 second.

As a result, the imaging device with shutter 6 can suppress the variation in the output video signal level due to the shading and color of the imaging object 9, and can obtain an image with stable brightness on the image recognition device 7.

FIG. 4 shows a third embodiment of the present invention.
The fact that the imaging object 9 carried by the transport device 8 has reached a certain point with respect to the imaging device with shutter 6 by the sensor 3 is output to the light emission timing control circuit 2 and the shutter timing control circuit 5. The shutter timing control circuit 5 controls the imaging object 9 in the same manner as in the first embodiment.
After delaying the time until the light reaches the imaging device 6 with the shutter, the light emission timing control circuit 2
The shutter timing is output to the imaging device 6 with the shutter a plurality of times during the light emission period of the illumination device 1 that has started emitting light by the output signal.

The images picked up by the plurality of shutter operations become a plurality of image signals having different exposure amounts from the relationship shown in FIG. 2, and the signals are input to the image signal selection circuit 11 so as to have the signal level expected in advance. By appropriately selecting the closest video signal, variations in the output video signal level of the imaging device with shutter 6 due to the shading and hue of the imaging object 9 are suppressed, and an image with stable brightness is displayed on the image recognition device 7. Obtainable.

As described above, the embodiments of the present invention include those having the following structures, functions, and actions.

In the illumination device and the imaging device with a shutter, the illumination device whose emission amount changes during the period from the start of emission to the end of emission is used. Based on the relationship of the change in the light emission amount, means for changing the time from the start of light emission of the illumination device to the shutter operation of the imaging device is provided to control the exposure amount.

In the illumination device and the imaging device with a shutter, the illumination device whose emission amount changes from the start of emission to the end of emission is used, and information on the color and shade of the object to be imaged is input in advance. A device for changing the time from the start of light emission of the illumination device to the shutter operation of the imaging device based on the information from the input device and the relationship between the change in the light emission amount of the illumination device; Is controlled.

In the illumination device and the imaging device with a shutter, an illumination device whose emission amount changes between the start of emission and the end of emission and which can emit light a plurality of times for one imaging object is used. Further, the image signal level of the imaging target obtained by performing one or more preliminary imaging using the imaging device capable of imaging a plurality of times for one imaging target and the light emission of the illumination device According to the relationship of the change in the amount, a means for changing the time from the start of light emission of the illumination device to the shutter operation of the imaging device at the time of actual imaging is provided to control the exposure amount.

In the illumination device and the imaging device with a shutter, the illumination device whose emission amount changes from the start of emission to the end of emission is used as the illumination device.
A plurality of video signals having different exposure amounts are obtained by giving a plurality of shutter timings to the image capturing apparatus by using an image capturing object that can perform multiple image capturing for a plurality of image capturing times, and from among these, image signals are expected in advance. A selector for selecting a video signal closest to the level is provided to control the exposure amount.

[0030]

According to the present invention, the exposure can be performed so that the output of the image pickup device with a shutter is constant without affecting the color tone and shading of the object to be imaged. be able to.

As a result, parameters such as threshold values in the image recognition processing can be made constant, and the algorithm can be simplified, and the recognition rate can be stabilized and improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an exposure control device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a change in light emission amount from the start of light emission to the end of light emission and shutter operation timing.

FIG. 3 is a diagram illustrating a configuration of an exposure control device according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of an exposure control device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Illumination device 2 Light emission timing control circuit 3 Sensor 4 Color tone information input device 5 Shutter timing control circuit 6 Imaging device with shutter 7 Image recognition device 8 Transport device 9 Object to be imaged 10 Required exposure amount calculation circuit 11 Video signal selection circuit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G03B 15/05 G03B 15/05 H04N 5/238 H04N 5/238 Z (72) Inventor Takayuki Tsutsumi Hitachi, Ibaraki 5-2-1, Omikamachi, Hitachi, Japan Hitachi Process Computer Engineering Co., Ltd. (72) Inventor Eiji Shimizu 5-2-1, Omikamachi, Hitachi City, Ibaraki Prefecture Hitachi Process Computer Engineering Co., Ltd. (72) Inventor Otake Atsushi 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture In-house Process Computer Engineering Co., Ltd. (72) Inventor Shigeru Naoi 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Omika Works, Hitachi, Ltd. (Reference) 2H002 CC00 CD00 CD13 DB00 FB21 GA13 GA16 GA31 GA32 JA11 2H053 AA01 AD00 AD03 AD23 DA00 5C022 AA13 AB15 AB17 AC42 AC52 AC69

Claims (4)

[Claims] 1. An exposure control device comprising an illumination device and an imaging device with a shutter, the exposure control device controlling an exposure amount for an imaging object having a change in color tone and shading, wherein the illumination device is configured to start emitting light and finish emitting light. An exposure control device that controls the exposure amount by changing a time interval from the start of the emission to the operation start timing of the shutter. 2. The exposure control apparatus according to claim 1, further comprising an input unit for inputting information on a color and a shade of the object to be imaged in advance, wherein the time interval is changed based on information from the input unit. An exposure control device, comprising: 3. An exposure control device including an illumination device and an imaging device with a shutter, the exposure control device controlling an exposure amount for an imaging object having a change in color tone and shading, wherein the illumination device is configured to start emitting light and finish emitting light. The pre-imaging is performed by one or more flashes according to a preset light emission start timing and a preset shutter operation timing, and the imaging object obtained in the preliminary imaging is obtained. Calculating the required exposure amount based on the video signal level of the above, and controlling the exposure amount by changing a time interval from the start of light emission to the operation start timing of the shutter based on the calculated required exposure amount. An exposure control device characterized by the above-mentioned. 4. An exposure control device comprising an illumination device and an imaging device with a shutter, the exposure control device controlling an exposure amount for an imaging object having a change in color tone and shading, wherein the illumination device is configured to start emitting light and finish emitting light. The amount of light emission varies between the light-emitting devices, and the image-capturing device captures a plurality of images for one light emission by the illumination device. An exposure control device for controlling an exposure amount by selecting a video signal closest to an expected video signal level from video signals.