JP2004072297A - Image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device having a focus assist function for easily adjusting a focus by using two-dimensional graph display and an image pickup device which has a similar structure and has a function for displaying an image pickup signal waveform by a two-dimensional graph. <P>SOLUTION: A focusing signal level showing a degree of focusing is stored in a one-dimensional memory with a focus ring position as an address. The focusing signal level which is read from the one-dimensional memory with a horizontal scanning position of a video signal as the address is compared with a vertical scanning position. Thus, the focus ring position and the focusing signal level are displayed in a view finder on a real time basis as the two-dimensional graph. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an imaging apparatus provided with a function of displaying a focus state and a white balance state of an image projected on a viewfinder (hereinafter, referred to as VF) as a two-dimensional graph, particularly in an imaging apparatus for broadcasting or business use. It concerns the device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an imaging apparatus having a function of assisting focus in a VF, for example, there is an imaging apparatus described in JP-A-11-127379 as shown in FIG.
[0003]
In FIG. 5, 1 is an imaging lens, 2 is an image sensor, 5 is a VF luminance signal (hereinafter, VF-Y) creating unit, 40 is a focusing signal creating unit, 10 is a combining circuit, and 11 is a VF output terminal. . The operation of the thus configured device will be described. The video signal obtained by the image sensor 2 is converted into a VF-Y by calculating the signals of the three primary colors at a predetermined ratio in the VF-Y creating unit 5. In addition, the focus signal creation unit 40 creates a focus signal indicating the degree of focus from the extracted high frequency component of the video signal. In other words, it utilizes the fact that the sharpness of the video signal increases when the image is in focus, and the included high frequency component increases. Examples of a method of creating a focus signal from a video signal include a method of summing a peak-to-peak value of a secondary differential value of the video signal or an absolute value of a secondary differential value of the video signal in the entire screen or an area of interest. There is. The display superimposed on the VF-Y signal is changed by the synthesizing circuit 10 according to the focus signal indicating the degree of focus created by the focus signal creation unit 40. Specifically, the in-focus signal is superimposed on the video signal by a bar display indicating a numerical value or a level and displayed on the VF.
[0004]
According to this conventional method, a peak value of a focus signal is acquired by rotating a focus ring of a lens over a sufficient angle range in advance, and a frame display such as 120 indicating the peak value is displayed. The focus signal is displayed as a bar like 121, or the focus signal at the time of actual shooting is normalized by a peak value and displayed as a numerical value to notify the optimum position of the focus ring.
[0005]
[Problems to be solved by the invention]
However, in the actual use of the imaging device, the subject being photographed changes every moment, and the peak value of the focus signal acquired in advance as in the above-described conventional imaging device is effective only under limited conditions. . Further, it is not realistic to perform a preliminary check operation of the peak value of the in-focus signal every time the focus is adjusted because it takes time each time. When the representative value of the signal that changes in this way is displayed in a one-dimensional manner such as a numerical value or a bar display, it is difficult to grasp the state near the extreme value of the signal, and it is difficult to stop the focus ring at a so-called justin position. .
[0006]
The present invention has been made in view of such a conventional problem, and has a similar structure to an imaging device having a focus assist function using a two-dimensional graph display for facilitating focusing. It is an object of the present invention to realize an imaging apparatus having a function of displaying a two-dimensional graph of an imaging signal waveform, which can be realized by the configuration.
[0007]
[Means for Solving the Problems]
In order to solve this problem, the invention of claims 1 to 3 of the present application
An imaging apparatus that inputs an imaging signal obtained through an imaging lens and an imaging element, displays a captured image on a VF, and outputs a focus state of the captured image to the VF as focusing information,
The focus information output to the VF indicates a focus ring position of the imaging lens in a horizontal direction, and indicates a level of a focus signal indicating a degree of focus created from an edge signal of the captured image in a vertical direction. The two-dimensional graph shown in FIG.
[0008]
The inventions of claims 4 to 6 of the present application
An imaging apparatus that inputs an imaging signal obtained through an imaging lens and an imaging element, displays a captured image on a VF, and outputs a focus state of the captured image to the VF as focusing information,
A one-dimensional memory that outputs stored content with the horizontal scanning position of the captured image as an address, and a comparison circuit that compares the vertical scanning position of the captured image with the output of the one-dimensional memory and outputs the focus information; A synthesizing circuit for inserting the output of the comparing circuit into the captured image.
[0009]
The invention according to claims 7 to 8 of the present application inputs an image pickup signal obtained through an image pickup lens and an image pickup element, displays a picked-up image on a VF, and outputs white balance information of the picked-up image to the VF. An imaging device,
A first one-dimensional memory that outputs storage content using the horizontal scanning position of the captured image as an address, a second one-dimensional memory that outputs storage content using the horizontal scanning position of the captured image as an address, A comparison circuit for comparing the vertical scanning position with the output of the first one-dimensional memory and the output of the second one-dimensional memory to output the white balance information; and inserting the output of the comparison circuit into the captured image And a synthesizing circuit.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0011]
(Embodiment 1)
FIG. 1 shows an embodiment of an image pickup apparatus according to the present invention. In FIG. 1, 1 is an image pickup lens, 2 is an image pickup element, 40 is a focus signal generation unit, 5 is a VF-Y generation unit, and 6 is a horizontal counter. , 7 are vertical counters, 80 is a one-dimensional memory, 90 is a comparison circuit, 10 is a synthesis circuit, and 11 is a VF output terminal.
[0012]
The operation of the imaging device configured as described above will be described below. An imaging signal output from the imaging element 2 via the imaging lens 1 is input to the VF-Y creation unit 5 and the focus signal creation unit 40. A focus signal indicating the degree of focus created from the edge signal of the imaging signal by the focus signal creation unit 40 is written to the one-dimensional memory 80 using the focus ring position signal 3 output from the imaging lens 1 as an address. Then, the contents of the one-dimensional memory 80 are read out in synchronization with the horizontal scanning of the imaging signal, using the horizontal scanning position of the imaging signal output from the horizontal counter 6 as an address. The comparison circuit 90 compares the level of the focus signal output from the one-dimensional memory 80 with the vertical scanning position of the image signal output from the vertical counter 7. The output of the comparison circuit 90 and the VF Y signal output from the VF-Y creation unit 5 are combined by the combining circuit 10 and output from the VF output terminal 11 as a VF signal.
[0013]
The screen display on the VF on which the above processing has been performed is as shown in FIG. 2, for example. That is, the level of the focus signal read from the one-dimensional memory 80 in synchronization with the horizontal scan is the level of the focus signal at the focus ring position corresponding to the horizontal scan position. Further, when the level of the focus signal corresponding to the vertical scanning position is lower than the level of the focus signal output from the one-dimensional memory 80 and higher than the minimum value of the focus signal, the flag signal is output from the comparison circuit 90. Then, when this flag signal is combined with the Y signal for VF by the combining circuit 10, it is displayed on the VF as a two-dimensional graph as shown by the hatched portion in FIG. Although not shown in FIG. 1, the scale conversion between the focus ring position signal and the horizontal scanning position of the imaging signal, and the scale conversion between the level of the focusing signal and the vertical scanning position of the imaging signal are performed as necessary. I do.
[0014]
When the photographer turns the focus ring, the contents of the one-dimensional memory corresponding to the latest focus ring position are overwritten by the latest focus signal, and the position corresponding to the latest focus ring position of the two-dimensional graph displayed in VF. Is replaced by the latest focus signal level. That is, the change in the focus ring position and the change in the focus signal level are reflected in real time on the VF display, and displayed together with the history of the focus signal level in the past, so that the just-in-time position at which the focus signal takes a local maximum value Judgment becomes easy.
[0015]
In the synthesizing circuit 10, the latest focus ring position may be specified by changing the brightness of the two-dimensional graph display at the horizontal scanning position corresponding to the latest focus ring position or adding a marker display. Further, the area in which the focus signal is calculated by the focus signal creation unit 40 may be changed according to the image to be captured, or the gain of the focus signal level display may be changed by the comparison circuit 90 or the like.
[0016]
In this embodiment, an example in which the focus ring position is set in the horizontal direction and the focus signal level is set in the vertical direction to display a two-dimensional graph is shown. However, the horizontal counter 6 and the vertical counter 7 are exchanged, and the focus ring position is set in the vertical direction. A two-dimensional graph display in which the focus signal level is taken in the horizontal direction may be used.
[0017]
(Embodiment 2)
FIG. 3 shows an embodiment of the imaging apparatus of the present invention. In FIG. 3, 1 is an imaging lens, 2 is an imaging element, 41 is a maximum value selection circuit, 42 is a minimum value selection circuit, 5 is a VF-Y creation unit, Reference numeral 6 denotes a horizontal counter, 7 denotes a vertical counter, 81 denotes a first one-dimensional memory, 82 denotes a second one-dimensional memory, 91 denotes a comparison circuit, 10 denotes a synthesis circuit, and 11 denotes a VF output terminal.
[0018]
The operation of the imaging device configured as described above will be described below. An imaging signal output from the imaging device 2 via the imaging lens 1 is input to the VF-Y creation unit 5, the maximum value selection circuit 41, and the minimum value selection circuit 42. The maximum value selection circuit 41 outputs the one having the highest signal level among the three channels (RGB) of the imaging signal. The minimum value selection circuit 42 outputs the one having the lowest signal level among the three channels (RGB) of the imaging signal. The output from the maximum value selection circuit 41 is written in the first one-dimensional memory 81 using the output of the horizontal counter 6 indicating the horizontal scanning position of the image signal as an address. Similarly, the output from the minimum value selection circuit 42 is written to the second one-dimensional memory 82 using the output of the horizontal counter 6 as an address. The writing to the first one-dimensional memory 81 and the second one-dimensional memory 82 is performed, for example, during a horizontal scanning period including the screen area used for the auto white balance processing. Then, the contents of the first one-dimensional memory 81 and the second one-dimensional memory 82 are read out in synchronization with the horizontal scanning of the imaging signal, using the horizontal scanning position of the imaging signal output from the horizontal counter 6 as an address. The comparison circuit 91 compares the signal level output from the first one-dimensional memory 81 and the second one-dimensional memory 82 with the vertical scanning position of the image signal output from the vertical counter 7. The output of the comparison circuit 91 and the Y signal for VF output from the VF-Y creation unit 5 are synthesized by the synthesis circuit 10 and output from the VF output terminal 11 as a signal for VF.
[0019]
The screen display on the VF after the above processing is as shown in FIG. 4, for example. That is, the signal level corresponding to the vertical scanning position is the maximum signal level for each pixel read from the first one-dimensional memory 81 in synchronization with horizontal scanning and the minimum signal level for each pixel read from the second one-dimensional memory 82. If the flag signal is output from the comparison circuit 91 and the flag signal is combined with the VF Y signal by the combining circuit 10, a two-dimensional graph as shown by the hatched portion in FIG. 4 is displayed on the VF. Here, although omitted in FIG. 3, the scale conversion between the level of the imaging signal and the vertical scanning position of the imaging signal is performed as needed.
[0020]
When a white balance is obtained by using the auto white balance function, it is not possible to confirm by color whether or not the white balance is properly obtained with a black and white display VF. Therefore, the white balance is confirmed by displaying the three-channel (RGB) signal waveform itself in a two-dimensional graph with respect to the horizontal line including the screen area used for the auto white balance processing. In the above-described configuration, a graph display is obtained as if the portion between the maximum signal level and the minimum signal level of the three channels (RGB) is painted, and the graph display is constricted as shown at 112 in FIG. The white balance state can be confirmed by the black and white VF.
[0021]
【The invention's effect】
As described above, according to the present invention, a two-dimensional graph can be displayed on a VF with a small-scale circuit using a one-dimensional line memory without requiring a two-dimensional frame memory. Further, since the two-dimensional graph is drawn by comparison with the counter values of the horizontal counter and the vertical counter indicating the scanning position of the imaging signal, high time response can be realized. Therefore, in the focus assist function, the focus ring position and the degree of focusing are easy to understand, and when the focus ring position is changed, the change in the focus signal is immediately reflected in the graph display. It becomes easier to find the position of the jaspin.
[0022]
Further, the signal waveform itself can be graphically displayed in black and white VF by a similar circuit, and a remarkable effect that the white balance can be visually confirmed can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a circuit configuration example of a focus assist function according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a VF display of the focus assist function according to an embodiment of the present invention. 3 is a block diagram showing a circuit configuration example of a white balance confirmation function according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of a VF display of a white balance confirmation signal waveform according to an embodiment of the present invention. FIG. 5 is a block diagram illustrating a circuit configuration example for realizing a conventional focus assist function. FIG. 6 is a diagram illustrating an example of a VF display of an imaging apparatus using the conventional focus assist function.
REFERENCE SIGNS LIST 1 imaging lens 2 imaging element 3 focus ring position 40 focus signal creation unit 41 maximum value selection circuit 42 minimum value selection circuit 5 VF luminance signal (VF-Y) creation unit 6 horizontal counter 7 vertical counter 80, 81, 82 primary Original memories 90, 91 Comparison circuit 10 Synthesis circuit 11 VF output terminal 100 VF screen 101 Two-dimensional graph display area 102, 103 Focus ring position index 104 Display of past focus signal history 105 Display of latest focus signal 110 Maximum value 111 showing the graph 120 showing the minimum value Frame display 121 Bar display of the focus signal level

Claims (8)

An image pickup apparatus that inputs an image pickup signal obtained through an image pickup lens and an image pickup element and displays a picked-up image on a viewfinder, and outputs a focus state of the picked-up image to the viewfinder as focusing information,
The focus information output to the viewfinder indicates a focus ring position of the imaging lens in a horizontal direction, and a level of a focus signal indicating a degree of focus created from an edge signal of the captured image in a vertical direction. An imaging apparatus, which is a two-dimensional graph indicating the following. The focus information output to the viewfinder is:
The imaging apparatus according to claim 1, wherein a display indicating a focus ring position of the imaging lens and a level of the focus signal at the same time is superimposed over a plurality of times. In the focusing information output to the viewfinder,
A display indicating the latest focus ring position of the imaging lens and the latest level of the focus signal, and a display indicating the past focus ring position of the imaging lens and the previous level of the focus signal are changed in luminance or 3. The imaging device according to claim 2, further comprising a display unit that is distinguished and recognized by marker display. An image pickup apparatus that inputs an image pickup signal obtained through an image pickup lens and an image pickup element and displays a picked-up image on a viewfinder, and outputs a focus state of the picked-up image to the viewfinder as focusing information,
A one-dimensional memory that outputs stored content with the horizontal scanning position of the captured image as an address, and a comparison circuit that compares the vertical scanning position of the captured image with the output of the one-dimensional memory and outputs the focus information; An image capturing apparatus comprising: a combining circuit that inserts an output of the comparison circuit into the captured image. 5. The imaging apparatus according to claim 4, wherein a focus ring position of the imaging lens is stored as an address, and a focus signal created from an edge signal of the captured image is stored as data in the one-dimensional memory. Data obtained by mixing the output of the storage content of the one-dimensional memory with the focus ring position of the imaging lens as an address and the focus signal created from the edge signal of the captured image at a ratio of 1 as data The imaging apparatus according to claim 4, wherein the one-dimensional memory stores the focus ring position of the imaging lens as an address. An image pickup device that inputs an image pickup signal obtained through an image pickup lens and an image pickup element and displays a picked-up image on a viewfinder, and outputs white balance information of the picked-up image to the viewfinder,
A first one-dimensional memory that outputs stored content using the horizontal scanning position of the captured image as an address, a second one-dimensional memory that outputs stored content using the horizontal scanning position of the captured image as an address, A comparison circuit for comparing the vertical scanning position with the output of the first one-dimensional memory and the output of the second one-dimensional memory to output the white balance information; and inserting the output of the comparison circuit into the captured image An imaging apparatus comprising: A maximum value circuit for outputting a maximum value of RGB signals of the image signal in a horizontal scanning period including a region used for calculating a white balance of the image signal, and a minimum value circuit for outputting a minimum value of RGB signals of the image signal Storing the horizontal scanning position of the captured image as an address, storing the output of the maximum value circuit as data in the first one-dimensional memory, addressing the horizontal scanning position of the captured image, and storing the output of the minimum value circuit as data. The imaging apparatus according to claim 7, wherein the image data is stored in the second one-dimensional memory.

Images