JP2001339733A - Light source selecting device of electronic still camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement a white balance adjustment in a manual operation quickly and certainly. SOLUTION: In a light source selector of an electronic still camera, a decision whether a manual white balance setting mode is set or not is made (STEP 101). At a setting of the manual white balance setting mode, a space distance H to an obstacle placed on a top of the camera is detected by a distance measuring sensor (STEP 102). When the space distance H is less than a specified value, it is estimated that the camera is now in a room, so that a room priority mode is selected (STEP 104). When the distance H is more than the specified value, it is estimated that the camera is now in an outdoors, so that an outdoor priority mode is selected (STEP 105).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an apparatus provided in an electronic still camera and for selecting a light source of a shooting environment in order to adjust white balance of an image obtained by shooting.

[0002]

2. Description of the Related Art Illumination light, that is, a light source in a shooting environment using an electronic still camera is sunlight, a fluorescent lamp, a tungsten lamp, or the like. Therefore, conventionally, the operation mode of white balance adjustment can be selected from an auto (automatic) / white balance adjustment mode and a manual (manual) / white balance adjustment mode.
Further, there has been proposed an electronic still camera which can be manually selected according to illumination light in a manual white balance adjustment mode. That is, indoor mode
The photographer manually switches between the outdoor mode and the outdoor mode. In the indoor mode, for example, it is determined that any one of a fluorescent lamp, a tungsten lamp, and a halogen lamp is used. The white balance adjustment according to is performed.

[0003]

However, such a switching operation is complicated, and if the switching operation is forgotten, there arises a problem that an appropriate white balance adjustment cannot be performed.

An object of the present invention is to provide an apparatus for selecting a light source of a photographing environment in order to enable quick and reliable white balance adjustment in a manual operation.

[0005]

According to the present invention, there is provided a light source selecting device, comprising: a location estimating means for estimating whether an electronic still camera is located indoors or outdoors; First light source selecting means for selecting the type of light source in the shooting environment in accordance with the indoor priority mode which is selected prior to the light source; and outdoor priority for selecting the light source for outdoor shooting in preference to the light source for indoor shooting. A second light source selecting means for selecting the type of light source of the photographing environment in accordance with the mode, and a mode for selecting one of the first and second light source selecting means in accordance with the location estimated by the location estimating means. And a selection unit.

The arrangement location estimating means includes, for example, a distance measuring means for measuring a distance from an upper surface of the electronic still camera to an obstacle. With this configuration, the location of the electronic still camera is estimated based on the measurement result of the distance to the obstacle.
In this configuration, the mode selecting means selects the first light source selecting means when the distance measured by the distance measuring means is smaller than a predetermined value, and the distance measured by the distance measuring means becomes larger than the predetermined value. Is larger, it is preferable to select the second light source selecting means.

On the other hand, the arrangement location estimating means may include illuminance measuring means for measuring the illuminance of light around the electronic still camera. With this configuration, the location of the electronic still camera is estimated based on the measurement result of the distance to the obstacle. In this configuration, the mode selecting means selects the first light source selecting means when the illuminance measured by the illuminance measuring means is smaller than a predetermined value, and the illuminance measured by the illuminance measuring means becomes smaller than the predetermined value. Is larger, it is preferable to select the second light source selecting means.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a state in which an electronic still camera to which the first embodiment of the present invention is applied is viewed from behind.

This electronic still camera is a single-lens reflex camera, and an interchangeable lens 11 is detachably attached to a camera body 90. An optical viewfinder 91 is provided at the center of the upper portion of the camera body 90, and the liquid crystal panel (liquid crystal display element) 46 is provided at substantially the center of the back surface 92. On the liquid crystal panel 46, an image obtained by the interchangeable lens 11 as a photographing optical system is displayed as a moving image, and a still image stored in a memory (not shown) can be displayed by a photographing operation. A mode setting switch 95 is provided beside the liquid crystal panel 46. The mode setting switch 95 is provided for setting various operation modes, and is a jog dial in the illustrated embodiment.

When the camera body 90 is viewed from the back 92, a shutter button 93 and a status display device 55 are provided on the upper right side of the camera body 90. Status display device 55
Is composed of a liquid crystal display element, on which the setting state of the type of the electronic still camera is displayed as characters or symbols.

A card slot 96 is formed on the side of the camera body 90. The card slot 96 is a PC card.
A card connector (not shown) is provided for inserting a card (memory card) into the camera body 90. A card connector (not shown) for mounting a PC card is provided inside the card slot 96. .

On the upper surface of the optical finder 91, a distance measuring sensor 94 is provided. The distance measuring sensor 94 includes an infrared light emitting element and an infrared light receiving element (not shown). The infrared light is emitted from the light emitting element, and reflected by an obstacle such as a ceiling to be received by the light receiving element. Is configured to be measured.

FIG. 2 is a block diagram mainly showing the electrical configuration of the electronic still camera. The interchangeable lens 11 is electrically connected to an electric circuit provided in the camera body 90 (FIG. 1) via the mount pins 12 and 13. Interchangeable lens 1
A front lens group 14 and a rear lens group 15 are provided in one lens barrel.
A stop 1 is provided between the lenses 14 and 15.
6 are provided. The lenses 14 and 15 are displaced in the direction of the optical axis under the control of the lens control circuit 17 to perform focus adjustment. The lens control circuit 17 is controlled by a system controller 31 provided in the camera body.
2 according to a control signal sent via the control signal 2. The aperture 16 is provided with an aperture driving circuit 32 provided in the camera body.
, And operates according to a control signal sent through the mount pin 13 to adjust the opening of the diaphragm 16. The aperture drive circuit 32 is controlled by the system controller 31.

In the camera body, lenses 14, 15
A half mirror 21 is provided on the optical axis. Halfmirror 21 is about 4 with respect to the optical axis of lenses 14 and 15.
It is fixed at a position inclined by 5 degrees. Half mirror
A focus plate 22 is provided above the focus plate 21.
A pentaprism 23 is provided above. Behind the pentaprism 23, the eyepiece 24 of the finder
Are arranged. Therefore, the light taken in from the lenses 14 and 15 is reflected by the half mirror 21, guided to the pentaprism 23 side, and the subject image is observed through the eyepiece 24.

An infrared cut filter 26 and an optical low-pass filter 27 are provided behind the half mirror 21. A CCD (image pickup device) 33 is provided behind the optical low-pass filter 27. Therefore, lens 1
The light taken in from 4 and 15 is transmitted through the half mirror 21 and is irradiated on the light receiving surface of the CCD 33. That is, an image obtained by the lenses 14 and 15 is formed on the light receiving surface, and the CCD 33 generates an imaging signal corresponding to the image.

A pulse signal generating circuit (PPG) 36 is connected to the system controller 31. The pulse signal generating circuit 36 is controlled by the system controller 31 to generate a seed signal.
Pulse signal is generated. The CCD drive circuit 37, the A / D converter 38, and the image signal processing circuit 39 are driven based on these pulse signals, and the operation of the CCD 33 is controlled by the CCD drive circuit 37. That is, the imaging signal read from the CCD 33 is converted into a digital signal by the A / D converter 38, and is subjected to predetermined image processing in the image signal processing circuit 39. Image signal processing circuit 39
Is connected to a memory 40 having a sufficient capacity to store digital image data corresponding to one image.

A monitor interface 41 and a card interface 42 are connected to the image signal processing circuit 39. These interfaces 41, 42
Is controlled by the system controller 31.

A backlight 45 and a liquid crystal panel 46 are connected to the monitor interface 41 via a liquid crystal drive circuit 44.
Is connected. In the liquid crystal panel 46, as described above, the liquid crystal drive circuit 44 is controlled based on the image pickup signal read from the CCD 33, so that the interchangeable lens 1
1 is displayed as a moving image, and
The liquid crystal drive circuit 44 is controlled based on the image data read from the memory 40, and a still image is displayed. A card connector 47 is connected to the card interface 42, and a PC card 43 can be attached to the card connector 47.

An AF sensor 51, a photometric sensor 52, an auto white balance (AWB) sensor 97, and a distance measuring sensor 94 are connected to the system controller 31. The AF sensor 51 has a conventionally known configuration, and the AF sensor 51 measures the focus adjustment state of the lenses 14 and 15. The aperture 16 at the time of exposure is
Opening degree and charge accumulation time in CCD 33 (exposure time)
And photometry for determining is performed. The auto / white balance sensor 97 has a light receiving sensor (not shown) for detecting light components of red (R), green (G) and blue (B). Used in adjustment. The distance measuring sensor 94 measures the distance from the upper surface of the camera body 90 to the obstacle as described above, and is used in a manual white balance setting mode as described later.

The system controller 31 includes a photometric switch 53, a release switch 54, and a status display device 5.
5 is connected. Metering switch 53 is shutter button 9
By half-pressing 3, it is turned on, whereby the photometry sensor 52 performs photometry. Relie
The push switch 54 is turned on by fully pressing the shutter button 93, whereby the imaging operation of the CCD 33 is started, and an imaging signal corresponding to an image is generated in the CCD 33.

Further, the system controller 31
Mode setting switch 95 is connected. The mode setting switch 95 is a jog dial as described above, and is set to a rotational position corresponding to the operation mode and pressed to set the operation mode. The operation modes include, for example, an auto white balance setting mode and a manual white balance setting mode, which will be described later.

FIG. 3 shows a diagram for adjusting the white balance.
7 is a flowchart of a light source selection routine for selecting a type of a light source in a shooting environment. This program is executed by the system controller 31.

In step 101, it is determined whether the manual white balance setting mode is set. The manual white balance setting mode is a mode in which the photographer manually selects the type of light source.
Is set by operating the mode setting switch 95. When the manual white balance setting mode is set, the process proceeds to step 102. When the manual white balance setting mode is not set, this routine is immediately terminated, and the auto white balance is set. Adjustment is performed. In the automatic white balance adjustment, white balance adjustment is performed based on data of each of the R, G, and B color components obtained by the automatic white balance sensor 97.

In step 102, the distance measuring sensor 94 is driven, and a spatial distance H to an obstacle located on the upper surface of the camera body 90 is detected. In many cases, the obstacle is the ceiling of the room in indoor photography, and is not present in outdoor photography in many cases. Even if the obstacle is present, it is often higher than the ceiling of a normal building.

In step 103, it is determined whether or not the spatial distance H is equal to or less than a predetermined value. The predetermined value is larger than the height of the ceiling of a normal building, for example, 5 m. When the spatial distance H is equal to or less than the predetermined value, step 104 is executed, the electronic still camera is estimated to be presently in the room, and the indoor priority mode is selected. The indoor priority mode is used to select the type of light source of the shooting environment in order to perform white balance adjustment on an image obtained by the electronic still camera.
In this mode, the light source in indoor photographing is selected prior to the light source in indoor photographing. In this embodiment, the light sources are selected in the following priority order.

(1) Fluorescent lamp (2) Tungsten lamp (3) Halogen lamp (4) Cloudy (5) Fine weather (daytime) (6) Fine weather (morning and evening)

That is, on the status display device 55, first, a mark indicating that the light source at the place where the electronic still camera is arranged is a "fluorescent lamp" is displayed. When the photographer presses the mode setting switch 95 in this state, "fluorescent light" is selected. On the other hand, the photographer sets the mode setting switch 95.
Is rotated by one click, for example, clockwise, a mark of "tungsten lamp" is displayed on the status display device 55. When the mode setting switch 95 is pressed in this state, the "tungsten lamp" is displayed. Selected. Similarly,
When the mode setting switch 95 is further rotated, the marks of "halogen lamp", "cloudy", "sunny day (daytime)" and "sunny day (morning and evening)" are changed and displayed for each click. The light source when the mode setting switch 95 is pressed is selected as the type of light source in the shooting environment.

On the other hand, in step 103, the spatial distance H
Is larger than the predetermined value, that is, when it is determined that there is no obstacle such as a ceiling relatively close above the electronic still camera, step 105 is executed. In step 105, the electronic still camera is presumed to be outdoors and the outdoor priority mode is selected. In the outdoor priority mode, when selecting the type of light source used in white balance adjustment, the light source in outdoor photography is selected with higher priority than the light source in indoor photography. In this embodiment, the light sources are selected in the following priority order.

(1) Cloudy (2) Fine weather (daytime) (3) Fine weather (morning and evening) (4) Fluorescent lamp (5) Tungsten lamp (6) Halogen lamp

That is, on the status display device 55, first, a mark is displayed to the effect that the light source at the place where the electronic still camera is located is outside light when the light source is "cloudy". When the photographer presses the mode setting switch 95 in this state, "cloudy" is selected. On the other hand, when the photographer rotates the mode setting switch 95 by, for example, one click in the clockwise direction, the status display device 55 displays a "fine weather (daytime)" mark.
When the mode setting switch 95 is pressed in this state, "sunny (daytime)" is selected. Similarly, when the mode setting switch 95 is further rotated, the marks of "sunny weather (morning and evening)", "fluorescent lamp", "halogen lamp", and "tungsten lamp" are changed and displayed every click. Then, the light source when the mode setting switch 95 is pressed is selected as the type of light source in the photographing environment.

As described above, in the manual / white balance setting mode, the type of light source in the photographing environment is selected by the photographer. Data indicating the type of the light source is transmitted to the image signal processing circuit 39, whereby the light source selection routine ends. In the image signal processing circuit 39, the R, G, and B color data (that is, still image data) read from the CCD 33 when the shutter button 55 is fully depressed. The coefficients are multiplied by coefficients corresponding to the types, and white balance adjustment is performed.

As described above, according to the first embodiment, whether the electronic still camera is indoors or outdoors is estimated based on the output signal of the distance measuring sensor 94, and based on the estimation result. Then, the indoor priority mode or the outdoor priority mode is selected, and the type of the light source is selected.
For example, when the electronic still camera is indoors, "fluorescent light" or the like is preferentially selected as a light source candidate, and when it is outdoors, external light in a "cloudy" situation is preferentially selected as a light source candidate. Is done. Therefore, the photographer does not need to be conscious of indoor shooting or outdoor shooting, and can always perform appropriate white balance adjustment.

FIG. 4 is a perspective view showing a state in which an electronic still camera to which the second embodiment is applied is viewed from the rear. The configuration that differs from the first embodiment is that an illuminance sensor 98 is provided on the upper surface of the optical finder 91, and the other configuration is the same. The illuminance sensor 98 includes a phototransistor or cadmium sulfide (CdS), and measures the illuminance of light around the electronic still camera.

FIG. 5 is a block diagram mainly showing the electrical configuration of the electronic still camera according to the second embodiment. The difference from the first embodiment is that an illuminance sensor 98 is connected to the system controller 31 instead of the distance measuring sensor 94, and the other points are the same.

FIG. 6 shows a diagram for adjusting the white balance.
7 is a flowchart of a light source selection routine for selecting a type of a light source in a shooting environment. This program is executed by the system controller 31.

The reference numeral of each step is basically the same as the light source selection routine of the first embodiment shown in FIG. 3, and the reference numeral of the corresponding step in the first embodiment is "100". Is added. That is, step 201 corresponds to step 101 in FIG.

The contents of step 201 are the same as step 101. In step 202, the illuminance sensor 98 is driven, and the illuminance E of the light irradiated on the upper surface of the camera body 90 is measured. In step 203, it is determined whether the illuminance E is equal to or less than a predetermined value. As the predetermined value, 300 lux, which is higher than 200 to 2000 lux, which is the normal indoor illuminance, is adopted. When the illuminance E is equal to or less than the predetermined value, step 204 is executed, and the indoor priority mode is selected. On the other hand, when the illuminance E is larger than the predetermined value, step 205 is executed, and the outdoor priority mode is selected.

The contents of the indoor priority mode and the outdoor priority mode are the same as in the first embodiment.

Although the same effects as those of the first embodiment can be obtained by the second embodiment, the second embodiment cannot be used at night.

[0040]

As described above, according to the present invention, the white balance can be quickly and reliably adjusted in the manual operation.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which an electronic still camera according to a first embodiment of the present invention is viewed from behind.

FIG. 2 is a block diagram mainly showing an electrical configuration of the electronic still camera according to the first embodiment.

FIG. 3 is a flowchart of a light source selection routine for selecting a type of a light source in a photographing environment for white balance adjustment in the first embodiment.

FIG. 4 is a perspective view showing a state in which an electronic still camera according to a second embodiment of the present invention is viewed from behind.

FIG. 5 is a block diagram mainly showing an electrical configuration of an electronic still camera according to a second embodiment.

FIG. 6 is a flowchart of a light source selection routine for selecting a light source type in a shooting environment for white balance adjustment in the second embodiment.

[Explanation of symbols]

 90 Camera body 94 Distance measuring sensor 95 Mode setting switch 98 Illuminance sensor

Claims (5)

[Claims] 1. An apparatus for selecting a type of a light source of a photographing environment in order to perform white balance adjustment on an image obtained by an electronic still camera, wherein the electronic still camera is located indoors or outdoors. Placement location estimating means for estimating the light source, and first light source selecting means for selecting the type of light source in the shooting environment in accordance with an indoor priority mode in which a light source in indoor shooting is selected prior to a light source in outdoor shooting. A second light source selecting means for selecting a type of light source in the shooting environment in accordance with an outdoor priority mode in which a light source for outdoor shooting is selected prior to a light source for indoor shooting, and an arrangement location estimating means. An electronic still camera, comprising: a mode selecting means for selecting one of the first and second light source selecting means in accordance with the arranged location. Light source selection device. 2. The light source selection device according to claim 1, wherein said arrangement location estimating means includes a distance measuring means for measuring a distance from an upper surface of the electronic still camera to an obstacle. 3. The method according to claim 1, wherein the mode selecting means is configured to execute the first mode when the distance measured by the distance measuring means is smaller than a predetermined value.
3. The light source selecting device according to claim 2, wherein the light source selecting device is selected, and the second light source selecting device is selected when the distance measured by the distance measuring device is larger than the predetermined value. 4. The light source selection device according to claim 1, wherein the arrangement location estimating means includes an illuminance measuring means for measuring an illuminance of light around the electronic still camera. 5. The illuminance measured by the illuminance measuring means is selected by the mode selecting means when the illuminance measured by the illuminance measuring means is smaller than a predetermined value. When the second value is larger than the predetermined value,
The light source selection device according to claim 4, wherein the light source selection means is selected.