JP3271309B2 - Camera device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state imaging device (CCD).
The present invention relates to a camera device suitable for use in a video camera device or the like that captures an image of a desired subject using an image sensor, and particularly to a camera device that performs focusing on a desired subject in accordance with the color of the subject.

[0002]

2. Description of the Related Art In recent years, it is easy to carry around,
Portable video camera devices that perform imaging with a solid-state imaging device (CCD image sensor) have become widespread because they can easily image a subject.

[0003] In the above-mentioned video camera device, the CCD image sensor receives imaging light emitted through an imaging lens. The CCD image sensor forms an image signal by performing the so-called photoelectric conversion of converting the received image light into an electric signal, and supplies the image signal to an image signal processing circuit. The imaging signal processing circuit performs predetermined signal processing such as adding a synchronization signal to the imaging signal, and supplies this to an electronic viewfinder and a recording head.

The recording head is a so-called rotary head, and records the image signal obliquely on a video tape. In addition, the above electronic viewfinder has a small CRT.
(Cathode ray tube) is provided, and the CRT is driven according to the image pickup signal. As a result, an image corresponding to the imaging signal is displayed on the CRT.
The CRT makes it possible to recognize the subject that is currently being imaged, and to image a desired object.

[0005] Here, such a video camera device is provided with a so-called auto-focus function for automatically focusing on a desired subject. The conventional autofocus function displays an image frame having a predetermined size and a fixed frame on the display screen of the CRT,
By detecting the contrast ratio of the subject shown in the center of the image frame (or in the image frame), and driving the imaging lens in parallel with the optical axis of the imaging light according to the detected contrast ratio. It was like controlling the focal length.

[0006]

However, the autofocus function provided in the conventional video camera apparatus is
Since the imaging lens is driven in accordance with the contrast ratio of the subject shown in the center of the image frame (or within the image frame), it is good if the subject is stationary, but if the subject is moving The focus cannot be adjusted unless the center of the image frame is aligned with the moving subject.
Therefore, there is a problem that it is difficult to focus on a moving subject.

Further, there is a case where it is desired to take an image of a subject located at the edge of the display screen instead of the subject located at the center of the image frame without moving the video camera device. In this case, since the focus is adjusted to the subject located at the center of the image frame, in order to image the subject located at the edge of the display screen without moving the video camera device, the auto focus function is required. Without relying on (turning off the autofocus function), it was necessary to manually move the imaging lens to perform focusing, which was very troublesome.

Further, since the electronic viewfinder generally displays a black and white image,
You may lose track of the desired subject during imaging, in which case,
It was very difficult to keep in focus on the lost subject.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and can focus on a moving subject, and can focus on a subject located at an edge of a display screen. It is another object of the present invention to provide a camera device having an auto-focus function that can automatically perform the automatic focusing.

[0010]

A camera device according to the present invention receives an image pickup light by a solid-state image pickup device, forms an image pickup signal by photoelectric conversion, and displays the image pickup signal on a display screen of an electronic viewfinder. In a camera device that captures an image of a subject, an imaging lens that focuses the imaging light and irradiates the solid-state imaging device with a variable focusing state and an imaging signal supplied through the solid-state imaging device are red. Color separation means for separating and outputting an image pickup signal for use in green, an image pickup signal for green, and an image pickup signal for blue; A distance measurement frame generating means for displaying a distance measurement frame, which is an image frame of the image, and an area value and a color of the object having the largest area among the objects displayed in the distance measurement frame. Color separation A color detection unit that detects from the imaging signals for each color supplied from the stage and outputs them as a color detection signal; and a motion that detects the motion of the subject from the color detection signal from the color detection unit and outputs a motion detection signal. Detecting means for generating a distance-measuring frame moving signal for moving a distance-measuring frame displayed on a display screen of the electronic viewfinder according to a motion detection signal from the motion detecting means. A distance measuring frame control unit that supplies the focusing state to the object from a video signal of the object within the distance measuring frame; and a focusing state of the imaging lens according to the detected focusing state. The above-mentioned problem is solved as a configuration characterized by having a focusing state control means for variably controlling the focal length.

[0011]

The camera device according to the present invention receives an image pickup light with a solid-state image pickup element, forms an image pickup signal by photoelectric conversion, displays the image pickup signal on a display screen of an electronic viewfinder, and picks up an image of a subject. When imaging is started, an imaging lens whose focus state can be varied focuses the imaging light and irradiates the solid-state imaging device.

The solid-state imaging device receives the imaging light, forms an imaging signal by photoelectric conversion, and supplies the imaging signal to an electronic viewfinder and color separation means. The electronic viewfinder is supplied with a distance measurement frame generation signal from a distance measurement frame generation unit in addition to the image pickup signal.
For this reason, the display screen of the electronic viewfinder
In addition to the subject that is currently being imaged, which is an image corresponding to the image signal, a distance measurement frame that is an image frame of a predetermined size is displayed.

The color separation means separates the image signal supplied through the solid-state image sensor into a red image signal, a green image signal, and a blue image signal, and supplies these to the color detection means. The color detection unit detects an area value of a subject having the largest area among the subjects displayed in the distance measurement frame and a color of the subject from an image pickup signal for each color supplied from the color separation unit, These are supplied to the motion detecting means as color detection signals.

The motion detecting means detects the motion of the subject from the color detection signal from the color detecting means, and supplies the motion detecting signal to the distance measuring frame control means. The distance measurement frame control means generates a distance measurement frame movement signal for moving the distance measurement frame displayed on the display screen of the electronic viewfinder according to the motion detection signal. Supply means.

The distance measuring frame generating means controls the electronic viewfinder to move the distance measuring frame displayed on the display screen of the electronic viewfinder according to the distance measuring frame moving signal. Thus, the distance measurement frame can be moved following the movement of the subject.

The focus state control means detects the focus state of the subject from the video signal of the subject in the frame for distance measurement, and determines the focus state of the imaging lens according to the detected focus state. Is variably controlled. As a result, it is possible to focus on the subject within the distance measurement frame displayed on the display screen of the electronic viewfinder.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the camera device according to the present invention will be described below with reference to the drawings.

The camera device according to the present invention can be applied to, for example, a video camera device as shown in FIG.
The video camera device of this embodiment is shown in FIG.
An imaging lens 1 that can change the focusing state for focusing and emitting imaging light, and a solid-state imaging device that receives imaging light from the imaging lens 1, performs photoelectric conversion, and forms and outputs an imaging signal. A CCD image sensor 2 and a color separation unit that separates and emits an image signal from the CCD image sensor 2 into a red (R) image signal, a green (G) image signal, and a blue (B) image signal. And a color separation circuit 3.

Further, the video camera device performs an image signal processing circuit 4 for subjecting the image signals for each color from the color separation circuit 3 to predetermined signal processing and outputs the processed signals, and an image signal from the image signal processing circuit 4. A recording head 6 for recording on a video tape 5, an electronic viewfinder 7 having a display screen such as a CRT (cathode ray tube) for displaying an image corresponding to an image signal from the image signal processing circuit 4, and an electronic viewfinder A distance measuring frame generating circuit 8 which is a distance measuring frame generating means for outputting a distance measuring frame generating signal for displaying a distance measuring frame which is an image frame on the display screen of the finder 7; An adder 9 is provided which superimposes the distance measurement frame generation signal from the distance measurement frame generation circuit 8 on the imaging signal from 4 and supplies the signal to the electronic viewfinder 7.

Further, the video camera apparatus can determine the area value of the object having the largest area and the color of the object among the objects displayed in the frame for distance measurement for each color supplied from the color separation circuit 3. A color detection circuit 10 which is a color detection means for detecting from an imaging signal and outputting these as a color detection signal
And the selection terminal 1 when the color tracking mode described later is set.
1a, the selected terminal 11b is selected, and the selected terminal 12a is controlled to be switched in conjunction with the selection of the selected terminal 12b. When the fixed frame mode is set, the selected terminal 11c is selected by the selection terminal 11a. Select and
When the color follow-up mode is selected, the first and second changeover switches 11 and 12 that are controlled to switch in conjunction with the selection terminal 12a to select the selected terminal 12c are selected.
A motion vector detecting circuit 13 which is a motion detecting means for detecting a motion amount of the subject from a color detection signal supplied from the color detection circuit 10 and supplied through the first changeover switch 11 and outputting a motion detection signal; are doing.

The video camera device outputs the motion detection signal from the motion vector detection circuit 13 in the color tracking mode, and outputs the color detection signal from the color detection circuit 10 in the fixed frame mode as it is. In the color tracking mode, the adder 14 and a distance measurement for moving a distance measurement frame displayed on the display screen of the electronic viewfinder 7 according to the motion detection signal supplied from the motion vector detection circuit 13. A frame moving signal is supplied to the distance measuring frame generating circuit 8, and in the fixed frame mode, the distance measuring frame displayed on the display screen of the electronic viewfinder 7 is fixed at the center of the screen. A distance measurement frame control circuit 15 that supplies a distance measurement frame control signal to the distance measurement frame generation circuit 8 and a video signal of a subject in the distance measurement frame. An AF (auto focus) circuit 16 which is a focus state control means for detecting a focus state of the object and variably controlling the focus state of the imaging lens 1 according to the detected focus state; I have.

Next, the operation of the video camera apparatus according to this embodiment having the above-described configuration will be described.

In the video camera apparatus according to the present embodiment, a distance measuring frame is fixedly displayed substantially at the center of the display screen of the electronic viewfinder 7, and the focus is on the subject within the fixedly displayed distance measuring frame. When a fixed frame mode for controlling the in-focus state of the imaging lens 1 so as to match, and when an object in the frame for distance measurement is specified by color and area value, the frame for distance measurement is followed by following the specified object. A color tracking mode for controlling the focusing state of the imaging lens 1 so as to move and focus on the specified subject is provided.

First, to set the fixed frame mode, the main power supply of the video camera device is turned on. Thereby, for example, a low-level voltage is supplied to the first and second changeover switches 11 and 12 via the input terminal 17. The first and second changeover switches 11 and 12 are:
When the low-level voltage is supplied, each of the terminals is turned off, and the selected terminal 11c is connected to the selected terminal 11a.
And the selected terminal 12c is selected by the selection terminal 12a.

In such a state, the imaging lens 1 focuses the imaging light and irradiates the light onto the CCD image sensor 2. The CCD image sensor 2 receives the imaging light, performs photoelectric conversion, forms an imaging signal, and supplies this to the color separation circuit 3. The color separation circuit 3 separates the image signal into image signals for each color of RGB, and supplies these to the color detection circuit 10 and the image signal processing circuit 4.

The imaging signal processing circuit 4 performs predetermined signal processing on the imaging signal for each color, and supplies this to the recording head 6 and the adder 9. The recording head 6 is a rotary head, and records the image signal obliquely on the video tape 5 by a so-called helical scan method.

As will be described later, a distance measurement frame generation signal for generating a distance measurement frame at the center of the display screen of the electronic viewfinder 7 is supplied from the distance measurement frame generation circuit 8 to the adder 9. Have been. The adder 9 superimposes the distance measurement frame generation signal on the image pickup signal and supplies the signal to the electronic viewfinder 7. As a result, on the display screen of the electronic viewfinder 7, a frame for distance measurement, which is an image frame of a predetermined size, is displayed together with the subject that is currently being captured, and it is possible to capture an image while confirming the captured object. it can.

On the other hand, the color detection circuit 10 calculates the area value of the object having the largest area among the objects displayed in the frame for distance measurement and the color of the object by the color separation circuit 3.
From the image pickup signals for each color supplied from the first selector switch 11 and the adder 1 as color detection signals.
The signal is supplied to the frame control circuit 15 for distance measurement via the fourth and second changeover switches 12.

As described above, in the fixed frame mode,
The color detection signal is supplied from the color detection circuit 10 to the distance measurement frame control circuit 15. In this case, the distance measurement frame control circuit 15 supplies the color detection signal supplied from the color detection circuit 10. The signal is supplied to the AF circuit 16 as it is, and a distance measurement frame fixing signal for fixing the distance measurement frame at the center of the display screen is supplied to the distance measurement frame generation circuit 8 and the AF circuit 16. .

As a result, as described above, a ranging frame generating signal for fixing the ranging frame is supplied from the ranging frame generating circuit 8 to the electronic viewfinder 7. The distance measurement frame displayed on the display screen is fixed.

The AF circuit 16 detects, for example, a contrast ratio of an object in the distance measuring frame displayed at the center of the display screen from the distance measuring frame fixing signal and the color detection signal, and detects the detected contrast. The above-described imaging lens 1 is controlled so as to be in a focused state according to the ratio. Thus, it is possible to automatically focus on the subject displayed in the distance measurement frame and perform imaging.

Next, the operation of the video camera device in the color tracking mode will be described with reference to the flowchart shown in FIG. First, the flowchart shown in FIG. 2 starts when the main power supply of the video camera device is turned on. As described above, when the main power supply is turned on, the video camera device automatically enters the fixed frame mode, and proceeds to step S1 in this state.

In step S1, a system controller (not shown) determines whether or not the mode changeover switch has been turned on.
The process proceeds to step S2, and if NO, the process proceeds to step S8.

That is, in order to set the video camera device to the color tracking mode, a mode switch (not shown) is turned on. In the step S2, the mode switching switch is turned on and the color tracking mode is turned on. It is determined whether or not the mode has been specified. When the mode switch is turned on,
A high-level voltage is supplied to the first and second changeover switches 11 and 12 via the input terminal 17. The first and second changeover switches 11 and 12
When the high-level voltage is supplied, the selection terminal 1
The selected terminal 11b is selected by 1a, and the selected terminal 12b is selected by the selection terminal 12a.

In step S8, since the mode changeover switch has not been turned on, the system controller controls the video camera device to execute the above-described fixed frame mode, which is the current mode. Return to

In step S2, the system controller determines whether or not the mode changeover switch has been turned on again in spite of the current color follow-up mode. If YES, the process proceeds to step S7; if NO, the process proceeds to step S7. Goes to step S3.

In step S7, since the mode changeover switch is turned on again in the color follow-up mode, the system controller sets the mode to the fixed frame mode and displays the distance measurement frame on the display screen. Return to center and finish.

In step S3, the color detection circuit 1
0 compares the values of the image pickup signals for the respective colors supplied from the color separation circuit 3 with each other, the object having the largest area indicated by oblique lines in the figure and the object among the objects displayed in the distance measurement frame. The color is detected and supplied as a color detection signal to the motion vector detection circuit 13 via the first changeover switch 11, and the process proceeds to step S4.

More specifically, as shown in FIG. 3A, the human clothing indicated by diagonal lines in the figure is detected as the subject having the largest area in the distance measuring frame 51, and the object is also detected. The colors of the clothes are detected, and these are supplied to the motion vector detection circuit 13 as the color detection signals. The color detection circuit 10 continues to detect a subject having the color and area values detected in step S3. In this case, the color detection circuit 10 detects a subject whose color and area values completely match. Rather than continuing, the object is detected with some allowance for the color and area values.

In step S4, the motion vector detection circuit 13 applies the color detection signal supplied from the color detection circuit 10 via the adder 14 and the second changeover switch 12 to the distance measurement frame control circuit. 15 as it is, and as shown by an arrow in FIG.
The motion of the subject is detected from the color detection signal, and a motion detection signal, which is a signal indicating the motion of the subject, is supplied to the distance measurement frame control circuit 15, and the process proceeds to step S5.

In step S5, the distance measurement frame control circuit 15 determines whether or not the motion of the subject has been detected from the motion detection signal. If NO, the process proceeds to step S4.
And the above-described routine is repeated, and in the case of YES, the process proceeds to step S6.

In the step S6, the distance measurement frame control circuit 15 determines the above-mentioned step S6 from the color detection signal and the motion detection signal supplied from the motion vector detection circuit 13.
It is determined whether or not the subject detected in step 3 exists in the display screen. If YES, the process proceeds to step S9, and if NO, the process proceeds to step S7.

In step S9, in step S3
Is present in the display screen, the distance measurement frame control circuit 15 outputs the distance measurement frame movement signal corresponding to the movement of the object to the distance measurement frame generation circuit 8 and the AF circuit. 16 and supplies the color detection signal to the AF circuit 16 and returns to step S4.

When the ranging frame moving signal is supplied from the ranging frame control circuit 15, the ranging frame generating circuit 8 generates a ranging frame corresponding to the ranging frame moving signal. A distance measurement frame generation signal for moving the distance measurement frame to a position corresponding to the movement of the subject, which is a signal, is supplied to the electronic viewfinder 7. Thus, as shown in FIG. 3C, the distance measuring frame 51 on the display screen of the electronic viewfinder 7 is indicated by a solid line in the figure from the position where the subject was present before, as indicated by a dotted line in the figure. Is moved to a position corresponding to the movement of the subject and displayed.

The AF circuit 16 calculates the distance measurement frame 5 based on the distance measurement frame movement signal and the color detection signal.
The in-focus state of the subject in the camera 1 is detected, and the in-focus state of the imaging lens 1 is variably controlled according to the detection result. Thus, even if the subject moves, the imaging lens 1 can be controlled so that the subject is kept in focus.

If NO is determined in step S6, in step S7, the distance measuring frame control circuit 15 determines that the subject detected in step S3 is not present in the display screen. The distance measuring frame generating circuit 8 is arranged so that the frame is returned to the center of the display screen and displayed.
Control. At this time, the AF circuit 16 controls the imaging lens 1 so that the subject displayed in the frame for distance measurement displayed in the center of the display screen is in focus, and ends.

As described above, in the color tracking mode, the area value and the color of the object having the largest display area among the objects within the distance measurement frame displayed on the display screen of the electronic viewfinder 7 are detected. Continue to detect the movement of a subject having this area value and its color, move and display the ranging frame according to the movement of the subject, and focus on the subject within the ranging frame. By controlling the imaging lens 1 as described above, it is possible to automatically focus on a moving subject, and to focus on a subject located at the end of the display screen without moving the video camera device. it can.

Therefore, when focusing on the subject located at the edge of the display screen, it is possible to save the troublesome trouble of manually moving the imaging lens 1 to focus.

Specifically, when it is desired to focus on a desired person in a crowd, if the skin color of the person is detected, the focusing is performed following the movement of the person. Can be done automatically.

In an electronic viewfinder for displaying a black-and-white image, the subject is difficult to recognize because the color is not displayed. Therefore, it is possible to prevent an imaging error such as defocusing caused when the subject moves unexpectedly.

Finally, the technical idea according to the present invention is to detect the area value and the color of the object having the largest area among the objects in the distance measuring frame displayed on the display screen of the electronic viewfinder to identify the object. Identify, detect the movement of the specified subject, move and display the distance measurement frame following the movement of the object, and focus on the specified object in the distance measurement frame. Is to control the imaging lens. For this reason, in the above-described embodiment, the camera device according to the present invention is applied to a video camera device, and an image pickup signal and the like are recorded on a video tape. It goes without saying that various changes can be made within a range not departing from the above-described technical idea, such as a configuration for outputting to a device or the like.

[0052]

The camera device according to the present invention can move the distance measurement frame displayed on the display screen of the electronic viewfinder following the movement of the subject. In addition, it is possible to focus on the subject within the distance measurement frame displayed on the display screen of the electronic viewfinder.

For this reason, it is possible to automatically focus on a moving subject, and to focus on the subject located at the end of the display screen without moving the video camera device. Therefore, when focusing on the subject located at the edge of the display screen, it is possible to save the troublesome trouble of manually moving the imaging lens and focusing.

Specifically, when it is desired to focus on a desired person in the crowd, if the skin color of the person is detected, the focusing is performed following the movement of the person. Can be done automatically.

In the electronic viewfinder for displaying a black-and-white image, the subject is difficult to recognize because the color is not displayed, and the subject tends to be lost even in the distance measurement frame. Focusing can be continued, and it is possible to prevent an imaging error such as defocusing caused when the subject moves unexpectedly.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment in which a camera device according to the present invention is applied to a video camera device.

FIG. 2 is a flowchart for explaining the operation of the video camera device of the embodiment.

FIG. 3 is a schematic diagram showing that a distance measurement frame displayed on an electronic viewfinder of the video camera device of the embodiment is moved according to a subject.

[Explanation of symbols]

1 imaging lens 2 CCD image sensor 3 color separation circuit 4 ..Imaging signal processing circuit 5 ... Video tape 6 ... Recording head 7 ... Electronic viewfinder 8 ... ······· Ranging frame generating circuit 9 ········································· Color detection circuits 11 and 12 ··· First , Second changeover switch 13... Motion vector detection circuit 14... Adder 15... Distance measurement frame control circuit 16. ······················································ Distance measuring frame

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/225-5/247

Claims (1)

(57) [Claims] 1. A camera device in which imaging light is received by a solid-state imaging device, an imaging signal is formed by photoelectric conversion, and the imaging signal is displayed on a display screen of an electronic viewfinder to image a subject. An imaging lens that converges imaging light and irradiates the solid-state imaging device with a variable focusing state; and converts an imaging signal supplied via the solid-state imaging device into a red imaging signal, a green imaging signal, and a blue imaging signal A color separation unit that separates and emits a signal, and supplies a distance measurement frame generation signal to the electronic viewfinder, and displays a distance measurement frame, which is an image frame of a predetermined size, on a display screen of the electronic viewfinder. A distance-measuring-frame generating unit that calculates the area value of the object having the largest area among the objects displayed in the distance-measuring frame and the color of the object from the image signals for each color supplied from the color separating unit. Inspection Color detection means for outputting these as color detection signals, motion detection means for detecting the motion of the subject from the color detection signals from the color detection means and outputting a motion detection signal, and motion from the motion detection means. Distance measurement frame control means for supplying a distance measurement frame movement signal for moving the distance measurement frame displayed on the display screen of the electronic viewfinder to the distance measurement frame generating means in accordance with the detection signal; A focus state control means for detecting a focus state of the subject from a video signal of the subject in the frame for distance measurement, and variably controlling a focus state of the imaging lens according to the detected focus state. A camera device comprising: