JP2002101420A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera that can easily recognize color temperature information in the case of photographing in an automatic white balance mode. SOLUTION: The electronic camera having a manual white balance mode and the automatic white balance mode displays a mark M4 denoting color temperature information at photographing on its display device in addition to a mark M1 denoting the automatic white balance mode. Marks M2-M7 denoting a position of the white balance or indication T denoting a color temperature itself may be used for the color temperature information. Or the color temperature information may be recorded on a memory card being a recording medium together with information data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an auto white balance mode for automatically setting a white balance,
The present invention relates to an electronic camera having a manual white balance mode in which a photographer can set a white balance.

[0002]

2. Description of the Related Art Conventionally, in an electronic camera having an auto white balance function, white balance adjustment according to lighting conditions is automatically performed on photographed image data so that a white object is accurately reproduced in white. Done. Furthermore, in addition to such an auto white balance function,
There are cameras that can manually set the white balance mode according to the shooting scene. Normally, if you are a photographer with extensive knowledge and experience about white balance, you can set the white balance mode appropriately according to the shooting scene even with manual, but if you are a photographer without knowledge, It is common to rely on the auto white balance function without using manual settings.

[0003]

However, when the auto white balance is unsuitable or the auto white balance reacts too sensitively, for example, a scene in which the color temperature changes moment by moment or a sunbeam through a tree. In a flickering scene, the white balance is difficult to match. As a result, the color tone often changes, making it impossible to shoot as desired. In such a case,
It is necessary to manually set an appropriate mode from a plurality of preset white balance modes or to correct the white balance. However, as described above, since a photographer who does not have knowledge of white balance always shoots with the automatic white balance, there is a problem that it is difficult to determine which white balance mode to set.

An object of the present invention is to provide an electronic camera which can easily obtain color temperature information at the time of photographing in an auto white balance mode.

[0005]

An embodiment of the invention will be described with reference to FIGS. 3 and 4. FIG. (1) The invention according to claim 1 is an image pickup means 26 for picking up a subject image and outputting image data, measuring means 7 and 21 for measuring the color temperature of the subject, and a plurality of white balances corresponding to different color temperatures. Mode setting means 44 for setting one of a manual white balance mode for selecting any one of the above and an automatic white balance mode for selecting an optimum white balance based on the color temperature obtained by the measuring means 7 and 21. And a processing unit 29 that performs white balance processing of image data based on a white balance selected according to a set mode. When the automatic white balance mode is set, the measurement unit 7 or 21 applies Color temperature information M indicating the white balance selected according to the measured color temperature
The above-described object is achieved by providing the display device 42 that displays 2 to M7, T and the mode information M1 indicating the auto white balance mode. (2) According to a second aspect of the present invention, in the electronic camera according to the first aspect, the display device 41 is provided in a finder. (3) The invention according to claim 3 is the electronic camera according to claim 1 or 2, further comprising an operation section 43 for instructing the display device 42 to display the color temperature information M2 to M7, T. And electronic camera. (4) The electronic camera according to any one of the first to third aspects, wherein the electronic camera according to any one of the first to third aspects records image data photographed in the auto white balance mode, mode information and color temperature information on the recording medium. It has a recording means 21 for performing the recording.

In the section of the means for solving the above problems, the drawings of the embodiments of the present invention are used to make the present invention easier to understand, but the present invention is not limited to the embodiments of the present invention. Not something.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a view showing one embodiment of an electronic camera according to the present invention, and is a cross-sectional view showing a main part configuration of the electronic camera. The electronic camera shown in FIG.
The camera includes a camera body 8, a finder device 9 that is attached to and detached from the camera body 8, and an interchangeable photographing lens 10 that contains the lens 1 and the aperture 2 and is attached to and detached from the camera body 8. The quick return mirror 3 is located at a position shown by a dotted line before being released, and the subject light incident on the camera body 8 through the photographing lens 10 is reflected by the main mirror 3a of the quick return mirror 3, Mirror 3a
Is transmitted.

The subject light transmitted through the main mirror 3a is
The light is reflected by the sub-mirror 3b and forms an image on the focus detection device 11. On the other hand, the subject light reflected by the main mirror 3a is guided to the finder device 9 and forms an image on the finder mat 12. Part of the subject light transmitted through the finder mat 12 is guided to the photometric element 7 through the pentaprism 6, the prism 14 and the imaging lens 15, and the remaining subject light is guided to the eyepiece 13 from the pentaprism 6. A CCD image sensor is used as the photometric element 7, and is disposed at a position conjugate with the imaging CCD 26 with respect to the lens 1. The shutter 4 is provided in front of the imaging CCD 26, and is closed before the release. When the release operation is performed, the quick return mirror 3 rotates to the position indicated by the solid line, the shutter 4 opens, and the subject image is captured by the imaging CCD 26.

FIG. 2 is a circuit block diagram of the electronic camera shown in FIG. 21 is a control circuit for controlling the entire camera, and 29 is an image processing circuit. The imaging CCD 26 accumulates signal charges corresponding to the brightness of the subject image.
Reference numeral 27 denotes an analog signal processing circuit including an AGC circuit, a CDS circuit, and the like, which performs analog processing such as gain control and noise removal on an image signal output from the imaging CCD 26. The A / D conversion circuit 28 converts the image signal analog-processed by the analog signal processing circuit 27 into a digital signal. The image processing circuit 29 performs image processing such as white balance adjustment, contour compensation, and gamma correction. The control circuit 21 controls the driving of the photographing CCD 26 via the timing generator 24 and the driver 25, and controls the analog processing circuit 27 and the A / D conversion circuit 2 while controlling the operation timing by the timing generator 24.
8 is controlled.

Reference numeral 30 denotes a buffer memory for temporarily storing image data before and after image processing. 3
A compression circuit 3 compresses the image data processed by the image processing circuit in a predetermined format, for example, in a JPEG format. Reference numeral 34 denotes a recording medium (memory card) detachably provided in the camera, and stores compressed or uncompressed image data and thumbnail image data with predetermined image information added thereto. The image data stored in the buffer memory 30 is processed by the display image creation circuit 31 into image data for display, and displayed as a photographing result on a monitor 32 provided in a camera. An LCD or the like is used for the monitor 32.

The control circuit 21 receives a half-press signal and a full-press signal from a half-press switch 22 and a full-press switch 23 interlocked with the release button. Shooting lens 1
The focus adjustment state of 0 is detected by the focus detection device 11,
Based on the detected value, the lens 1 is driven to the in-focus position by the lens driving device 37 so that the subject light forms an image on the photographing CCD 26. The photometric element 7 has the CC as described above.
A D image pickup element is formed, and a subject image is formed on the image pickup surface. The image signal output from the photometric element 7 is A / D
The signal is converted into a digital signal by the conversion circuit 36 and input to the control circuit 21. The control circuit 21 calculates the subject brightness based on the image data from the photometric element 7 and calculates the color information. The white balance adjustment of the image data obtained by the photographing CCD 26 is performed based on the color information. Here, the color information includes, for example, an output ratio of R, G, and B obtained by decomposing image data into three primary colors of R (red), G (green), and B (blue).

Reference numeral 35 denotes a shutter drive circuit for controlling the opening and closing of the shutter 4; 39, a mirror drive circuit for moving the quick return mirror 3 up and down;
Reference numeral 45 denotes an electronic flash device, which controls an aperture amount of the aperture 2 based on subject luminance information from the camera. Also,
Reference numeral 41 denotes a liquid crystal display device in the finder for displaying photographing information in the finder. Reference numeral 42 denotes a liquid crystal display device provided on the upper surface of the camera body or the like for displaying various information necessary for photographing and reproduction. Reference numeral 44 denotes a white balance mode switching button for switching a plurality of types of white balance modes. Reference numeral 43 denotes a color temperature or a mark corresponding to the color temperature in the automatic white balance mode.
2 and a color temperature display button for displaying on the monitor 32.

<< Explanation of Photographing Operation >> Next, the photographing operation will be described. When the release button (not shown) is half-pressed and the half-press switch 22 is turned on, a focus adjustment operation is performed to drive the lens 1 to the in-focus position, and the
Of the subject brightness based on the output of. Following the ON operation of the half-press switch 22, the full-press switch 23
Is turned on, the quick return mirror 3 rotates upward, and the CCD 26 captures a subject image. CC
The signal charges stored in D26 are swept out by the driver 25 and input to an analog signal processing circuit 27 including an AGC circuit and a CDS circuit.

In the analog signal processing circuit 27, analog processing such as gain control and noise removal is performed on the analog image signal, and then converted into a digital signal by an A / D conversion circuit 28. The digitally converted signal is input to the image processing circuit 29, where image preprocessing such as white balance adjustment, contour compensation, and gamma correction is performed, and is temporarily stored in the buffer memory 30. Thereafter, image data is read from the buffer memory 30 into the image processing circuit 29, and white balance adjustment is performed according to the set white balance mode. The image data after the white balance adjustment is stored in the buffer memory 30 again.

The image data stored in the buffer memory 30 is processed into image data for display by a display image creation circuit 31 and displayed on a monitor 32 as a photographed result.
The image data in the buffer memory 30 is transmitted to the compression circuit 33.
Is compressed. In the compressed image data,
Predetermined data names, date and time data, and photographing information data recording photographing conditions such as a shutter speed and an aperture value at the time of photographing are attached, and these are recorded on the memory card 34.

<< Adjustment of White Balance >> The light quality of a light source is represented by a color temperature, which is about 5200K under fine weather and about 4200K under a fluorescent lamp. When looking at things with the naked eye,
Since the color is corrected by the eyes adapting to the ambient light, a white subject is recognized as white even in fine weather or illuminated by a fluorescent lamp. However, in physical photometry using a CCD such as the photometry element 7, the spectral distribution of reflected light differs between when a white subject is imaged under clear sky and when it is imaged by illuminating with a fluorescent lamp. The balance changes. Therefore, in an electronic camera, white balance adjustment is performed so that a white object is reproduced with accurate white under illumination of any color temperature. For example, if the image data is R (red),
It is separated into three primary colors of G (green) and B (blue), and the gains of R and B are controlled so that the output ratios of the three colors R, G and B are adjusted to be equal.

The white balance adjustment varies depending on the lighting conditions. In the electronic camera according to the present embodiment, a predetermined white balance mode can be manually set according to a shooting scene, and an automatic white balance automatically set to an optimum white balance is set. It has a balance mode.
These mode switching can be performed by the WB mode switching button 44 in FIG. In the present embodiment, as modes that can be manually set, a bulb mode (color temperature of 3000 K) suitable for shooting under a white light bulb, a fluorescent lamp mode (color temperature of 4200 K) suitable for shooting under a fluorescent light, and Fine weather mode (color temperature 5200K) suitable for photography, flash photography mode (color temperature 5400K) suitable for photography using the electronic flash device 45, cloudy sky mode (color temperature 6000K) suitable for photography under cloudy weather, There are six modes, a fine shade mode (color temperature 7000K) suitable for shooting in the shade. In the auto white balance mode, the color temperature of the illumination light is estimated from the image data obtained by the photometric element 7, and the optimal mode for the estimated color temperature is selected from the above six modes and is automatically set. Therefore, in the auto white balance mode, the color temperature 42
It can correspond to lighting conditions of 00K to 7000K.

For example, when photographing is performed under illumination of a fluorescent light, if the image is displayed without white balance adjustment, the subject image becomes bluish. In such a case, when the fluorescent light mode is set by the WB mode switching button 44, the photographing CC is set based on the fluorescent light mode adjustment setting stored in advance.
The gains of R and B of the image data obtained by D are controlled, and R and B are adjusted so that a white subject is reproduced in accurate white.
The output ratio of G and B is adjusted. On the other hand, when shooting is performed under fluorescent light illumination in the auto mode, the control circuit 21 separates the image data from the photometric element 7 into three primary colors, and converts the image data into the obtained R, G, and B information. The color temperature is calculated based on the color temperature. In this case, since a color temperature around 4200K is obtained, white balance adjustment is performed based on the fluorescent lamp mode adjustment setting. As described above, in the auto mode, the lighting condition at the time of photographing is calculated based on the image data from the photometric element 7, and the mode optimal for the lighting condition is automatically selected and the white balance is adjusted.

<< About white balance mode display >>
Next, the display relating to the white balance mode will be described. In the electronic camera according to the present embodiment, which mode of the white balance mode is selected is displayed on the liquid crystal display device 42. FIG. 3 shows an example of a mode display displayed on the liquid crystal display device 42, and FIG. 3 (a) shows an example of a mark corresponding to each mode. In FIG. 3A, mark M1 is in auto white balance mode, mark M2 is in bulb mode, mark M3 is in fluorescent mode, mark M4 is in clear sky mode, mark M5 is in flash photography mode, and mark M6 is cloudy. Mode, and the mark M7 represents the fine weather shade mode. The mode display is not limited to the liquid crystal display device 42, but may be displayed on the liquid crystal display device 41 in the finder, the monitor 32, or the like.

The white balance mode switching button 44 shown in FIG.
Each time is operated, the mode is switched, and changes cyclically as in auto white balance mode → bulb mode → fluorescent mode → sunlight mode → flash shooting mode → cloudy mode → sunshine mode → auto white balance mode.
At this time, if a mode other than the auto white balance mode is set, only the mark of the set mode is displayed on the display device 42. On the other hand, when the automatic white balance mode is set, the mode adjustment setting at the time of white balance adjustment is automatically performed based on the color temperature information obtained from the image data captured by the photometric element 7 as described above. Will be

When the color temperature display button 43 in FIG. 2 is depressed, as shown in FIG. 3B, a mark M1 indicating the automatic white balance mode and a mode setting mark corresponding to the color temperature at that time. Is displayed. FIG.
In the example of (b), the fine weather mode is automatically set to the mode adjustment setting, and the mark M4 corresponding to the fine weather mode is displayed. In FIG. 3B, a broken line indicates a non-display mark, and the marks M2, M3, M5, M6, and M7 are in a non-display state.

Instead of displaying the marks M2 to M7, the actually calculated color temperature T itself may be displayed as shown in FIG. In the example of FIG. 3C, it is displayed that the color temperature T is 5200K. In this embodiment, the color temperature information such as the mark M4 in FIG. 3B and the color temperature display T in FIG. 3C is displayed by pressing the color temperature display button 43. Alternatively, it may be displayed when the release button is half-pressed and the half-press switch 22 is turned on.

As described above, in the electronic camera of the present embodiment, the color temperature information during shooting is displayed in the auto white balance mode, so that even a novice user can obtain the actual shooting scene, color temperature and lighting conditions. You can easily understand the correspondence. By gaining such experience, even when the white balance must be set manually, it is possible to quickly determine which mode to set.

The color information in the auto white balun mode described above is not only displayed on the liquid crystal display device 42 but also recorded on the memory card 34 as one of the photographing information data. FIG. 4 is a diagram showing an example of photographing information data attached to image data. By operating an operation button (not shown) or the like provided on the camera, the photographing information data display as shown in FIG. 32 can be displayed. In the display example shown in FIG. 4, (a) shows the shooting information data when the white balance mode is manually set to the fine weather mode, and (b) and (c) show the shooting information data when the shooting is performed in the auto white balance mode. The photographing information data is shown.

In the examples shown in FIGS. 4A to 4C, the sensitivity, white balance mode, white balance correction, gradation correction level, contour emphasis level, and focal length are displayed in order from the top. In the manual mode in FIG. 4A, information “SUNNY” indicating the fine weather mode is recorded as white balance mode information. On the other hand, in the auto white balance mode shown in FIG. 4B, information "AUTO (5200K)" indicating that the mode is automatic and the color temperature is 5200K is recorded as white balance mode information. Also, in FIG. 4C, “S” representing an illumination condition is used instead of the color temperature “5200 K” in FIG.
UNNY "is recorded. By examining such photographing conditions after photographing, it is possible to learn how to set the white balance mode in manual operation. Note that the shooting information includes, in addition to the information shown in FIG. 4, a camera name, a firmware version, a metering mode, a shutter speed, an aperture value, an exposure mode,
Exposure compensation, etc.

In the correspondence between the embodiment described above and the elements of the claims, the photometric element 7 and the control circuit 2
1 is a measuring means, a white balance mode switching button 44 is a mode setting means, an image processing circuit 29 is a processing means, marks M2 to M7 and a color temperature display T are color temperature information, a mark M1 is mode information, The temperature display button 43 constitutes an operation unit, the control circuit 21 constitutes recording means, and the memory card 34 constitutes a recording medium.

[0027]

As described above, according to the present invention,
When the auto white balance mode is set, the color temperature information is displayed in addition to the mode information, so that the correspondence between the actual shooting scene and the color temperature or lighting conditions can be easily understood. By using the color temperature information display at the time of setting the automatic white balance mode, it is possible to accurately and quickly set the mode in the manual white balance mode. In particular, in the invention of claim 4, since the mode information and the color temperature information are recorded on the recording medium together with the image data, it is possible to examine the relationship between the photographed scene and the white balance mode after photographing,
Knowledge about white balance can be increased.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of an electronic camera according to the present invention, and is a cross-sectional view illustrating a main part configuration of the electronic camera.

FIG. 2 is a circuit block diagram of the electronic camera shown in FIG.

FIGS. 3A and 3B show an example of a mode display displayed on the liquid crystal display device 42. FIG. 3A is a diagram showing marks M1 to M7, FIG. () Is a diagram showing another example of the display at the time of auto.

4A and 4B are diagrams illustrating an example of photographing information data. FIG. 4A illustrates an example of data in a manual mode, FIG. 4B illustrates an example of data in an automatic mode, and FIG. 4C illustrates another example of data in an automatic mode. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens 2 Aperture 3 Quick return mirror 4 Shutter 7 Photometry element 9 Finder device 11 Focus detection device 21 Control circuit 26 Photographing CCD 29 Image processing circuit 34 Memory card 41 Liquid crystal display in finder 42 Liquid crystal display device 43 Color temperature display button 44 White Balance mode switch button M1 to M7 Mark T Color temperature display

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C022 AA13 AC03 AC07 AC09 AC12 AC32 AC42 AC52 AC54 5C065 AA03 BB02 BB04 BB05 CC01 CC08 CC09 DD02 EE01 EE02 FF02 FF03 GG44 GG49 5C066 AA01 BA01 BA13 CA08 CA13 EA15 GA01 FA02 GB01 HA03 KA12 KE19 KM02 KM13 LA02

Claims (4)

[Claims] An imaging unit that captures a subject image and outputs image data; a measurement unit that measures a color temperature of the subject;
One of a manual white balance mode for selecting any one of a plurality of white balances corresponding to different color temperatures and an automatic white balance mode for selecting an optimal white balance based on the color temperature obtained by the measuring unit Mode setting means for setting crabs,
A processing unit for performing white balance processing of the image data based on a white balance selected according to the set mode. An electronic camera, comprising: a display device that displays color temperature information indicating a white balance selected according to a temperature and mode information indicating an auto white balance mode. 2. The electronic camera according to claim 1, wherein the display device is provided in a viewfinder. 3. The electronic camera according to claim 1, further comprising an operation unit for instructing display of the color temperature information on the display device. 4. The electronic camera according to claim 1, wherein the image data photographed in the auto white balance mode, the mode information, and the color temperature information are recorded on a recording medium. An electronic camera comprising: