JPH0534574A - Image pickup device - Google Patents

Abstract

PURPOSE:To provide an image pickup device which executes an automatic focusing and/or an automatic iris action based on an object viewed by a photographer. CONSTITUTION:This device is equipped with a finder 1 provided with an infrared diode 2 and a photodiode 3, a gazing point detection circuit 4 which detects a gazing point and a gazing point area generation circuit 8 which generates a gazing point area by interlocking with the gazing point. Then, the automatic focusing and/or the automatic iris action is executed by interlocking with the gazing point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device.

[0002]

2. Description of the Related Art In an image pickup apparatus such as a conventional video camera / still camera, the autofocus operation is performed by extracting a high frequency component of an image pickup luminance signal obtained from a central portion of an image pickup element using a high pass filter. This is performed by detecting the focus evaluation value every fixed period (for example, one field period), and adjusting the distance between the image sensor and the camera lens so that the value takes the maximum value.

Further, in the auto iris operation, the image pickup luminance signals obtained from the central portion of the image pickup device are averaged by using an integrating circuit, the amount of light incident on the image pickup device is converted into a DC voltage value, and based on this, the aperture is stopped. The amount of light incident on the image pickup device was kept constant by opening and closing.

[0004]

However, in the conventional image pickup apparatus, the auto focus and auto iris operations are
The center portion of the image pickup device is set as an auto focus area and an auto iris area, and the image pickup luminance signal obtained from the area is used. For this reason, in the auto focus operation, if the target subject is outside the focus area, the subject is out of focus and does not operate normally. On the other hand, the auto iris operation, when there is a subject outside the iris area and there is a large difference in brightness inside and outside the iris area,
The subject did not work properly because it was blackened when the subject was backlit and white when the subject was normally illuminated.

Therefore, the present invention has been made in view of the above problems.
It is an object of the present invention to provide an imaging device that operates based on a subject that a photographer is gazing at.

[0006]

The present invention provides the following means in order to solve the above problems.

A finder having a light emitting portion which emits light toward the eyepiece portion and a light receiving portion which receives only the reflected light from the light emitting portion reflected on the eyepiece portion side, and each portion of the eyepiece portion. First detecting means for detecting a change in the amount of reflected light at the eyepiece, based on a light receiving signal output from a light receiving portion for respectively receiving the reflected light partially reflected from the first detecting means, and the first detecting means.
The image pickup apparatus is configured to set a desired photographing state by specifying at least a gazing point of a subject in accordance with a detection signal from the detection unit.

In the above-mentioned image pickup apparatus, the control means for controlling the light emitting operation of the light emitting portion with periodicity, and the second detection for detecting the periodicity of the light emitting operation from the light receiving signal which fluctuates according to the light emitting operation. And an image pickup device.

[0009]

1 is a block diagram for explaining the main part of an embodiment of an image pickup apparatus according to the present invention, FIG. 2 is a layout diagram of an infrared light emitting diode and a photodiode, and FIG. 3 is a gazing point detection circuit. 4 is a circuit diagram for explaining the relationship with the photodiode, FIG. 4 is a timing chart for explaining the operation of the pulse detection circuit 7, and FIG. 5 is a schematic diagram for explaining the movement of the gazing point. Embodiments will be described below with reference to the drawings.

The outline of the image pickup apparatus of this embodiment is that a sensor for detecting a gazing point is provided inside the finder, and which part of the image on the monitor in the finder is being gazed is detected. , Auto focus, and auto iris operation. Here, the gazing point means one point of the subject gazed by the photographer, and the gazing point area means a certain range including the gazing point.

Referring to FIG. 1, first, the gazing area generating circuit system AA will be described with reference to FIGS.

In order to detect the gazing point, infrared rays are emitted to the photographer's eye on the eyepiece side of the finder 1 from the infrared light emitting diode 2 (LED) arranged inside the finder 1 provided with the monitor 9. After irradiating, the reflected infrared rays are received by the photodiode 3 (PD) and photoelectrically converted, and then predetermined processing is performed by the gazing point detection circuit 4 described later. That is, the fact that the reflectance of infrared rays differs between the white-eye portion and the black-eye portion of the photographer's eyeball is utilized, and this is utilized. Here, as shown in FIG. 2, the infrared light emitting diode 1 and the photodiode 3 are arranged, and the photodiode 3 is the first and second photodiodes that play a role of specifying the position of the black eye portion in the vertical direction. 31, 3
2 and third and fourth photodiodes 33 and 34 which play a role of specifying the position of the black eye portion in the left-right direction.

The gazing point detection circuit 4 is composed of an adder circuit 41 shown in FIG. 3A and a differential circuit 42 shown in FIG. 3B, and the adder circuit 41 has a boundary between a black eye portion and a white eye portion. The signals obtained by photoelectrically converting the infrared rays reflected from the lower part of each of the first and second photodiodes 31 and 32 are added to obtain the vertical direction detection signal 41a. On the other hand, the differential circuit 42 transmits the infrared rays reflected from the left and right portions of the boundary between the black eye portion and the white eye portion to the third and fourth photodiodes 33 and 3.
The signals obtained by photoelectric conversion in 4 are subtracted to obtain the horizontal direction detection signal 42a.

The vertical direction detection signal 41a is supplied to the sample hold circuit 6, while the horizontal direction detection signal 42a is supplied to the sample hold circuit 6 and the pulse detection circuit 7, respectively. Here, a pulse detection circuit 7 described later
Plays a role of detecting whether or not the photographer is looking into the finder 1. The infrared light emitting diode 2 which is an infrared light emitting source is driven by the drive pulse 5a supplied from the infrared light emitting diode drive circuit 5, and operates to repeat light emission at regular intervals. Therefore, the vertical direction detection signal 41a and the horizontal direction detection signal 42a are signals synchronized with the light emission cycle of the infrared light emitting diode 2.

First, the operation of the pulse detection circuit 7 will be described with reference to FIG. 4, in which FIG.
The output signal of the bandpass filter obtained through the bandpass filter (not shown) in the pulse detection circuit 7 is shown in FIG. Since the bandpass filter is for detecting the infrared light emitted from the infrared light emitting diode 2 in the left-right direction detection signal 42a, its center frequency is substantially equal to the light emission repetition frequency of the infrared light emitting diode 2. ing. Then, the bandpass filter output signal is binarized through a comparator (not shown) having the voltage Vr shown in FIG. 7B as a threshold value, and then the pulse detection circuit output signal 7a obtained by frequency-voltage conversion is obtained. It shows in (C).

In this way, the gazing point area generation circuit 8
When the pulse detection circuit output signal 7a supplied to is high level, the photographer is looking into the finder 1, and when it is low level, the photographer is not looking into the finder 1 and outside light is incident. It can be determined that

Next, the sample hold circuit 6 will be described. Using the sample pulse 5b synchronized with the drive pulse 5a supplied from the infrared light emitting diode drive circuit 5, the vertical and horizontal direction detection signals 41a and 42a are sampled respectively. The first and second sample-and-hold circuit output signals 6a and 6b obtained by removing the pulse waves held and superposed on both signals are supplied to the gazing area generating circuit 8.

The gazing point area generating circuit 8 sets the area in the center of the screen while the pulse detection circuit output signal 7a is at the low level, and outputs the first and second sample and hold circuit outputs at the high level. An area corresponding to the movement of the gazing point is set based on the signals 6a and 6b.

The operation will be described below.
The sample-and-hold circuit output signals 6a and 6b are subjected to analog-to-digital conversion to obtain first and second coordinate signals representing vertical and horizontal coordinates according to the movement of the gazing point. FIG. 5A illustrates the movement of the gazing point based on the first and second coordinate signals. Since the figure (A) includes a sudden movement of the gazing point, it is necessary to remove it.
Therefore, a digital low-pass filter is applied to each of the first and second coordinate signals to remove the sudden movement of the gazing point. The movement of the gazing point is illustrated on the basis of the thus obtained third and fourth coordinate signals in FIG. Then, for example, when the pulse detection circuit output signal 7a is at a high level, the digital information representing the pre-divided area R to which the gazing point belongs, while when at a low level gazing point, the area Q corresponding to the central portion of the screen is displayed. Of the digital information representing the respective points of interest as area-of-focus area signals 8a, which will be described later.
Supply to 9 and 16 respectively.

In this way, the gazing point area can be determined, and based on this, the auto focus and auto iris operations described below are performed.

First, the autofocus operation will be described. The incident light 11a is incident on the camera lens 11 and the diaphragm 1 is used.
2 is used to form an image on the image pickup surface of an image pickup device (not shown) in the image pickup circuit 13, and the image pickup video signal 13 obtained by photoelectric conversion is obtained here.
a is supplied to the video signal processing circuit 14.

Then, the first luminance signal 14a having a synchronizing signal obtained by performing well-known video signal processing such as gamma correction in the video signal processing circuit 14 is supplied to the monitor drive circuit 10 and is not shown. The second luminance signal 14b having no synchronizing signal is supplied to the bandpass filter 15, the first window circuit 19 and the attenuator circuit 21 via the A / D converter.

Then, in the bandpass filter 15, the second
The bandpass filter output signal 15a having a digital value obtained by extracting the high frequency component of the luminance signal 14b of the above is supplied to the second window circuit 16, where the gazing point based on the gazing point area signal 8a. Second window circuit output signal 1 obtained by extracting the bandpass filter output signal 15a in the area
6a is supplied to the peak hold circuit 17.

Then, in the peak hold circuit 17, the second
Of the peak hold circuit output signal 17a obtained by detecting the maximum value of the window circuit output signal 16a of the microcomputer 1
8 and the focus motor control signal 18a is supplied to the focus motor 23 for driving the camera lens 11 so that it takes the maximum value, that is, the contrast is increased.

Next, to explain the auto iris operation,
The second luminance signal 14b supplied to the first window circuit 19
Is supplied to the first integrator circuit 20 as the first window circuit output signal 19a by extracting only the signal within the gazing area based on the gazing area signal 8a. The first integration circuit output signal 20a obtained by averaging the first window circuit output signal 19a is supplied to the microcomputer 18.

Further, the second luminance signal 14b supplied to the attenuating circuit 21 is attenuated at a constant ratio and supplied to the second integrating circuit 22 as an attenuating circuit output signal 21a, where the attenuating circuit output is outputted. The second integration circuit output signal 22a obtained by averaging the signal 21a is the microcomputer 18
Supply to.

Then, the microcomputer 18 weights and averages the first and second integrator circuit output signals 20a and 22a at a predetermined ratio and determines the aperture ratio of the diaphragm based on the weighted average, thereby obtaining an iris motor control signal 18b. Are supplied to an iris motor 24 that drives the diaphragm 12.

In this way, when the photographer is looking into the viewfinder 1, the auto focus and auto iris operations are performed based on the gazing area, while when the photographer is not looking into the viewfinder, the image pickup screen is displayed. The auto focus and auto iris operations are performed based on the constant range of.

In the above embodiment, the first luminance signal 14a may of course be a composite video signal including a color signal.

In the above-described embodiment, the second luminance signal 14b is supplied to the subsequent stage structure via the A / D converter, but it is inserted between the video signal processing circuit 14 and the microcomputer 18. It is needless to say that the above A / D converter may be omitted by performing the analog operation of the above configuration.

In the above embodiment, the finder 1 is described as an electronic finder having a monitor, but the present invention is not limited to this, and it goes without saying that it may be an optical finder without a monitor. is there.

In the above-described embodiment, the gazing area generating circuit AA is not used only for the auto focus and auto iris operation. For example, in the case of a video camera, recording start, recording end, zoom, etc. on the monitor 9 are performed. It may be possible to control the video camera by displaying various operating modes of the camera, and in the case of a still camera, various operating modes such as shutter, shutter speed, and zoom are displayed in the optical viewfinder. However, it goes without saying that the still camera may be controlled by gazing at this.

As described above, according to this embodiment, since the auto focus and auto iris operations are performed based on the gazing area, the auto focus and auto iris operations can be performed based on the subject viewed by the photographer.

As described above, according to this embodiment, since the infrared light emitting diode 2 and the photodiode 3 are provided in the finder 1, the gazing point can be detected without burdening the photographer while selecting the subject. it can. Further, since the gazing point is detected by emitting and receiving infrared rays, the gazing point can be detected without imposing a burden on the photographer, and the gazing point can be surely detected without being affected by the monitor.

As described above, according to the present embodiment, the photographer does not look into the finder 1 because the pulse detector circuit 7 for detecting whether or not the photographer looks into the finder 1 is provided. Also in this case, the auto focus and auto iris operations can be performed, and shooting can be performed in various modes.

[0036]

As described above, according to the present invention, it is possible to set a desired photographing state by specifying the gazing point of a subject. Therefore, for example, in an image pickup apparatus that performs an auto focus and / or an auto iris operation. Has the effect that the auto focus and / or the auto iris operation can be performed based on the subject the photographer is gazing at.

Further, according to the present invention, the finder is provided with a light emitting portion that emits light toward the eyepiece side and a light receiving portion that receives only the reflected light from the light emitting portion reflected by the eyepiece side. Since the above is provided, there is an effect that the gazing point can be detected without burdening the photographer while checking the subject to be photographed.

According to the present invention, the control means for controlling the light emitting operation of the light emitting portion with periodicity, and the second means for detecting the periodicity of the light emitting operation from the light receiving signal which fluctuates according to the light emitting operation. It is possible to determine whether or not the photographer is looking into the viewfinder, and for example, when it is determined that the photographer is not looking into the viewfinder, the image is displayed within a certain range in the imaging screen. By performing the auto focus and / or the auto iris operation based on this, there is an effect that it is possible to perform shooting in various modes.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a main part of an embodiment of an image pickup apparatus according to the present invention.

FIG. 2 is a layout view of an infrared light emitting diode and a photodiode.

FIG. 3 is a circuit diagram for explaining a relationship between a gazing point detection circuit and a photodiode.

FIG. 4 is a timing chart for explaining the operation of the pulse detection circuit 7.

FIG. 5 is a schematic diagram for explaining a movement of a gazing point.

[Explanation of symbols]

 1 finder 2 infrared light emitting diode 3 photodiode 7 pulse detection circuit 8 gazing point area generation circuit 5a drive pulse

Claims (2)

[Claims] 1. A finder having a light emitting portion that emits light toward the eyepiece side and a light receiving portion that receives only reflected light from the light emitting portion that is reflected by the eyepiece side, and the eyepiece portion. First detecting means for detecting a change in the amount of reflected light at the eyepiece, based on a light receiving signal output from a light receiving portion that receives the reflected light partially reflected from each portion, and the first detection means. An image pickup apparatus configured to set a desired photographing state by specifying at least a gazing point of a subject according to a detection signal from the means. 2. The image pickup device according to claim 1, wherein the control means for controlling the light emitting operation of the light emitting portion with periodicity, and the light emitting operation with the periodicity of the light receiving signal varying according to the light emitting operation. An image pickup apparatus comprising: a second detection unit for detecting.