JPH0334778A - Electronic camera - Google Patents

Abstract

PURPOSE:To confirm whether or not a detail of an object image is also accurately focused by providing a picture magnification means magnifying and displaying a picture on a picture monitor means and magnifying and displaying the picture prior to image pickup. CONSTITUTION:An output of a signal processing unit 6 is fed to a recording circuit 7 and also to a picture magnification circuit 11 magnifying the picture and the magnified picture is displayed on an electronic view finder 10 by controlling a drive signal with a command from a CPU 8. Thus, in the case of applying focus adjustment, even the information of a detailed part of an object image hardly reproduced on a view finder is focused with a very high accuracy.

Description

Detailed Description of the Invention (a) Field of Application of Rakudo The present invention relates to an electronic camera that converts image information into an electrical signal and outputs the electrical signal.

(Prior Art) Conventionally, as devices for converting image information into electrical signals and outputting them or recording them on a recording medium, there have been known video cameras for moving images and still video cameras for recording still images. There is.

FIGS. 5 and 6 are block diagrams of main parts of a conventional electronic camera. In FIG. 5, 1 is a photographing lens, 2 is a half mirror, 3 is a shutter, 4 is an image sensor consisting of a CCD, and 5 is a focus screen.
The light beam passing through the photographic lens 1 is divided into 2 parts by the half mirror 2.
The light is divided and supplied to the shutter 3 and focus screen 5, respectively. The light beam guided to the shutter 3 forms an image on the imaging surface of the CCD 4 via the shutter 3. Furthermore, the light rays directed toward the focus screen 5 form an image of the subject on the focus screen 5. The output of the image sensor 4 is converted into R, G, and B images 1 by a signal processing circuit 6.
No. 3 and a composite synchronization signal are generated. 7 is a recording device which, in the case of still video, performs FM modulation on the video signal in the form of a luminance signal and a color difference line sequential signal, and further performs DPSK modulation on an ID signal that collects various control information related to image information; It is designed to record multiplexed images. Reference numeral 8 denotes a control circuit which supplies operation commands to and controls each block including the shutter 3 and the recording device 7, and is constituted by a CPU.

The focus screen 5 is arranged at a position optically equivalent to the CCD tffi image element 4, and by observing the subject image formed on the focus screen 5,
The in-focus state of the CD image sensor 4 can be confirmed.

Further, FIG. 6 shows another example of a conventional electronic camera. That is, instead of the shutter 3 shown in FIG. 5, an exposure control device 9 causes the CCD image sensor 4 to perform a shutter operation electronically. Signal processing device 6
The output of It is possible to confirm the determined camera angle and the in-focus state of the subject image.

(Problem to be Solved by the Invention) However, according to the conventional device as described above, when focusing on a subject, the photographer has to focus his/her eyesight on a specific part of the focus screen or the screen of the electronic viewfinder. Also, the photographer must concentrate his/her attention, which makes the photographer tired.

Another problem is that it is difficult to focus on fine details of the subject or on the details within the subject. This causes difficulty in focusing even when the aperture is narrowed down and the depth of field is deep, or when the zoom state of the lens is set to the wide side.

Incidentally, in recent years, there has been a strong demand for higher image quality in video equipment such as video cameras and electronic still cameras, and various measures are being taken to improve image quality. In the field of electronic cameras as well, proposals have been made to improve image quality by shifting and expanding the luminance signal band in a video signal to a higher frequency band. Therefore, even when recording, it is possible to record and reproduce more delicate images, so even if only the signal processing system has high image quality, unless focusing is performed with high precision during recording,
Unable to take advantage of its strengths. Therefore, when adjusting the focus, there has been a demand for an apparatus that can perform the adjustment operation with high precision, is easy to operate, and is easy to judge whether or not the object is in focus.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and includes an imaging means for converting a subject image formed on an imaging surface into an electrical signal, and an image monitor means for monitoring a video signal outputted from the means; an image enlarger means for enlarging and displaying a predetermined portion of the subject image on the image monitor means; and a display indicating that the image has been enlarged by the image enlarger. The display means is equipped with a display means for displaying an enlarged image before photographing, so that it can be confirmed whether even the details of the subject image are accurately focused, and the enlarged image is displayed. This is to make the user aware of this.

〔Example〕

The electronic camera according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of an electronic camera according to the present invention, and the same components as those of the conventional example in FIGS. 5 and 6 are designated by the same reference numerals.

In the figure, C is located behind the subject of the imaging lens 1.
A CD image sensor 4 is arranged, and the CCD 1 most image element 4 is connected to an exposure control device 9 and a signal processing device 6.
The output of the signal processing device 6 is supplied to a recording circuit 7 and also to an image enlarging circuit 11 for enlarging the image.

The output of the image enlargement circuit 11 is supplied to an image display device, that is, an electronic viewfinder 10. Further, the recording device 7, the exposure control circuit 9, the image enlarging means 11, etc. are all configured to be controlled by control command signals output from the control CPU. Further, S is an image enlargement switch, and by operating the switch S, a command to enlarge the image is supplied to the image enlargement circuit 11 via the CPU 8.

Therefore, the subject image formed by the imaging lens 1 on the imaging surface of the c c D image sensor 4 is converted into an electrical signal, and the signal is output to the signal processing circuit 6 and then supplied to the signal processing circuit 6 .

The signal processing circuit 6 forms R, G, and B video signals and a composite synchronization signal from the signal from the CCD image sensor 4, and supplies the signal to the recording circuit 7. The signal is then converted into a predetermined recording signal in the recording circuit 7 and recorded on a magnetic disk (not shown).

On the other hand, the image enlarging circuit 11 receives R and G from the signal processing circuit 6.
, which generates a drive signal for driving the image display device 10 from the B video signal and the composite synchronization signal.
By controlling the drive signal according to the command from 8, an enlarged image can be displayed.

FIG. 2 shows horizontal drive signals and vertical drive signals when a CRT is used as the image display device 10. In FIG. 2(A), a is a horizontal drive signal on a normal screen, and this sawtooth wave sweeps the electron beam in the horizontal direction. In the figure, the vertical axis indicates the amplitude of the video signal, and the horizontal axis indicates time. The horizontal blanking period is not displayed.In other words, the amplitude of the sawtooth wave indicates the scanning (display) range in the horizontal direction on the CRT screen, and the horizontal axis indicates the portion of the video signal input in time series that is displayed on the CRT. Therefore, when displaying an enlarged image, only the portion C in the figure is enlarged in the horizontal direction on the CRT of the image display device to by using the drive signal shown by the dotted line in the same figure. Similarly, the image can be enlarged in the vertical direction by changing Tribe No. 3. In Figure 2 (B), d shows the vertical drive signal waveform on a normal screen. , In the figure, similarly to Fig. 2(A), the vertical axis indicates amplitude and the horizontal axis indicates time. Also, ■1 indicates the vertical scanning period;
■2 is the vertical retrace period. The amplitude indicates the scanning (display) range in the vertical direction, and the horizontal axis indicates the range of information to be displayed on the CRT in each horizontal scanning inputted in time series. Therefore, when displaying an enlarged image, by changing to the vertical drive signal indicated by the dotted line e in the figure, only the information signal in the horizontal scan indicated by f in the figure is CR.
The images are enlarged and displayed in the vertical direction on T, resulting in an image enlarged in the vertical direction. In this way, horizontally,
In the vertical direction, the drive signals are shown in Fig. 2 (A
) By making the changes shown in e in FIG. 2(B), the image information in the range C1 in the horizontal direction and f in the vertical direction is enlarged and displayed on the entire screen of the CRT. Further, due to the enlargement of the image, R, G, and B video signals other than the portions C and f in each figure are not displayed.

Furthermore, by changing the positions of C and f in FIGS. 2(A) and 2(B), CCD j! Image element 4
It is possible to enlarge any part of the subject image formed on the imaging plane.

That is, since an electronic viewfinder, which is usually formed of a small CRT, cannot display and reproduce image information in detail, it is difficult to make a focus judgment on details that cannot be reproduced on the screen. Therefore, if image information recorded slightly out of focus is played back on a high-definition, large-screen monitor, etc., the subtle defocus will be played back with degraded image quality. Even if you try to improve the image quality, even the slightest shift in focus will degrade the image quality.7Therefore, as mentioned above, when shooting, switch S is operated and the image enlargement circuit is activated to display the electronic viewfinder as an image display device. By enlarging and displaying a part of the above image, detailed image information that cannot be discerned on the viewfinder can be partially displayed as an enlarged image, so when adjusting the focus, you can easily see the subject image. Even detailed information that cannot be reproduced on the viewfinder can be focused with extremely high precision.

The image enlargement circuit 11 has the above-mentioned configuration, and converts the normal horizontal and vertical drive signals ad (FIG. 2) into horizontal and vertical drive signals for displaying an enlarged image,
The control operation to change to e (Fig. 2) is performed by the CPU 8, and therefore the subject to be photographed,
After determining the camera angle, etc., it is possible to switch to an enlarged image using, for example, a switch S, and check whether the details of the subject image are also in focus. The switch S is ON only when it is pressed and switches to an enlarged image, or it is ON.

It may also be a device that selectively becomes a stable position when it is OFF.

When the enlarged image is displayed, the CPU 8 displays signal B on the image display unit 10, that is, in the viewfinder, and the enlarged image mode is indicated by superimposing characters and marks. . In this way, the enlarged image is different from the angle of view at which it is actually photographed, and is therefore done to make the user aware of the mode of the image.

FIG. 3 shows another embodiment of the image enlarging circuit of the present invention. According to this embodiment, the image enlarging circuit 12 is a CCD
It is arranged between the image sensor 4 and the signal processing circuit 6, and its configuration and operation will be explained using FIG.

In the figure, 121 is a clock generator which outputs a read clock to the CCD image sensor 4. CCDtaC
It is supplied to the signal processing device 6 via the CD image sensor 4 switch 122 and the IH (H is horizontal scanning period) delay line 123, and the output of the delay line 123 is sent to the switch 1.
22 to the unconnected input terminal of the CCD image sensor 4.

In addition, the clock generator 121 and the switch 122 are connected to the CPU.
It is controlled by the commands of No. 8.

During the horizontal scanning period, the clock generator 121 generates a slower clock than usual for the portion that needs to be enlarged, and generates a faster clock during the horizontal retrace period for the portions before and after the enlargement portion for reading. In this way, reading in the horizontal direction can be performed only for the enlarged portion. In addition, in the vertical direction, the clock generator 1
21, for parts where the vertical scanning period needs to be expanded,
One horizontal line of the CCD li image element 4 is read out once every predetermined number of times during the horizontal scanning period, and the IH delay line 123 is read out.
By circulating the same horizontal line using the switch 122, one horizontal line on the ccotffi image element 4 is repeatedly output over several horizontal scanning periods. This allows the image to be enlarged and displayed in the vertical direction.

In this case as well, the image enlarging circuit is operated by operating the switch S, as in the first embodiment, and when photographing, the image is enlarged by temporarily turning on the switch S, and the focus state is adjusted. This makes it easy to confirm.

Further, in the embodiments of the present invention, it is also possible to use a large-capacity memory as an image enlarging means to capture an image signal, and digitally extract and reconstruct the image signal of a portion to be enlarged.

Furthermore, in the above embodiment, the method of changing the scanning range as an image enlargement means and the method of changing the readout range of COD were described, but the image information signal is once stored in the memory, and when reading the image information from the memory, By controlling the readout sheet address, only the image information of a specific portion can be extracted and displayed on the display device 10. At this time, by enlarging a part of the image, the display device 10 Il
If the number of pixels on the image information side is smaller than the number of pixels in l, processing such as interpolation may be performed.

At this time, by enlarging a part of the image, the display device 1
If the number of pixels on the image information side is smaller than the number of pixels on the 0 side, processing such as interpolation may be performed.

Furthermore, when a liquid crystal display or the like is used as the image display device, it goes without saying that the waveform of the drive signal in FIG. 2 is changed by an address signal specifying the drive line of the liquid crystal display.

Further, the image pickup device is not limited to a CCD, but may be an MO3 type image pickup device, and the present application is also effective for image pickup tubes.

[Effects of the Invention] As described above, according to the present invention, it is possible to enlarge any part of a photographed image without changing the state of the optical system using mechanical means. The in-focus state can be determined accurately.

Therefore, the precision of focus adjustment can be improved and the focus adjustment operation can be made easier.

Furthermore, since the state of the optical system itself is not changed even when this image is enlarged, operability is good and there is no inconvenience such as missing a photo opportunity, so it is very effective when applied to cameras.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the electronic camera of the present invention, FIG. 2 is a drive signal waveform diagram for explaining the present invention in detail, and FIG. 3 is a block diagram showing another embodiment of the present invention. figure,
FIG. 4 is a block diagram showing the structure of the image enlarging means in the embodiment of FIG. 3, and FIGS. 5 and 6 are block diagrams showing the structure of a conventional electronic camera. /Lji ni shadow)Z/! ,B Izo [Pζ-Suite j1 Imato 2bu (Switch Keiya, s'7 Boofs?kun

Claims (1)

[Claims] an imaging means for converting a subject image formed on an imaging surface into an electrical signal; an image monitoring means for monitoring a video signal output from the imaging means; and an image monitoring means for enlarging a predetermined portion of the subject image. An electronic camera comprising: an image enlarging means for displaying an image; and a display means for displaying that the image has been enlarged by the image enlarging means.