JP4940072B2 - Imaging apparatus, control method, and program - Google Patents

Description

The present invention is related to a technique for controlling the light amount of the display means.

  2. Description of the Related Art Conventionally, an imaging apparatus such as a digital camera includes an imaging element such as a CCD or a CMOS sensor that photoelectrically converts a subject image, and a liquid crystal having backlight illumination for displaying an image signal generated by the imaging element. A display panel is provided. Since such a liquid crystal display panel is usually installed on the back surface of the body of the imaging device, there is a problem that the visibility of the display on the liquid crystal display panel is deteriorated in a bright environment such as outdoors.

In order to avoid such deterioration of the visibility of the liquid crystal display panel, in Patent Document 1, the brightness of the subject is measured from the captured image, and the backlight is turned on and off based on the photometric result. A method has been proposed.
JP 2004-228722 A

  However, in the method of Patent Document 1 described above, since the backlight is controlled by measuring the brightness of the subject rather than the brightness of the light hitting the liquid crystal display panel on the back of the body, the backlight is not necessarily turned on and off. It is not always properly controlled. In other words, when the light beam state is different between the photographer's position and the subject's position (for example, when shooting in a backlight environment), turning on and off may be reversed and visibility is improved. There was a problem that it was not always.

Accordingly, the present invention shall be the purpose of improving the visibility of Viewing means.

Imaging device according to the present invention includes an imaging means for generating image signals from the Utsushitai image via an optical system for refracting an erect image, for guiding the subject image formed on the focusing screen in the optical viewfinder a first position, and photometric means for metering a mirror movable in a second position for guiding the imaging means an image of an object, the light incident through the optical system, before you In the state where the lens is moved to the second position, the finder reverse incident light incident from the optical finder is measured by the photometric means, and the image signal generated by the imaging means is displayed according to the photometric result. and having a control unit for controlling the light amount of the display means for.

A control method of an imaging apparatus according to the present invention includes an imaging means for generating image signals from an object image via an optical system for refracting the erect, the object image formed on the focusing screen in the optical viewfinder a first position for guiding, a mirror movable in a second position for guiding the subject image to the imaging means, and a photometric means for metering the light incident through the optical system a control method for controlling an image pickup apparatus having, before a state where you error is moved to the second position, meters finder reverse input light incident from the optical viewfinder in the photometry means, the light measurement result depending on, characterized by the step of controlling the light amount of the display means for displaying an image signal generated by the imaging means.
In addition, a program for causing a computer to execute the control method for an image pickup apparatus according to the present invention forms an image on a focusing screen through an image pickup unit that generates an image signal from a subject image and an optical system for refracting an erect image. Measure a light incident through the optical system and a mirror movable to a first position for guiding the subject image to the optical viewfinder and a second position for guiding the subject image to the imaging means. A program for causing a computer to execute a control method for controlling an imaging device having a photometric means for detecting finder reverse incident light incident from the optical viewfinder in a state where the mirror is moved to the second position. Metering is performed by the light metering means, and the light quantity of the display means for displaying the image signal generated by the imaging means is controlled according to the light metering result. And characterized in that it has a-up.

According to the present invention, Ru can improve the visibility of Viewing means.

  Hereinafter, an embodiment in which the present invention is applied to a digital camera will be described in detail with reference to the accompanying drawings.

(Configuration of digital camera)
FIG. 1 is a block diagram showing the configuration of the digital camera of this embodiment.

  In FIG. 1, reference numeral 100 denotes an interchangeable lens unit on which the photographing lens 5 is mounted, and reference numeral 200 denotes a digital camera body as an imaging device.

  The photographic lens 5 is usually composed of a plurality of lenses, but here it is simplified and shown as a single lens. Reference numeral 6 denotes a communication terminal for the lens unit 100 to communicate with the digital camera body 200, and reference numeral 10 denotes a communication terminal for the digital camera body 200 to communicate with the lens lens unit 100. The lens unit 100 communicates with the microcomputer 37 in the digital camera main body 200 through the communication terminals 6 and 10, and controls the diaphragm 1 through the diaphragm driving circuit 2 by the internal lens system control circuit 4. Further, the subject is focused by displacing the position of the lens 5 via the AF (autofocus) drive circuit 3.

  Reference numeral 11 denotes an AF (autofocus) sensor that outputs defocus amount information to the microcomputer 37. The microcomputer 37 controls the lens unit 100 based on the defocus amount information and performs focusing.

  A quick return mirror 12 is moved up and down (moved) by an actuator (not shown) based on an instruction from the microcomputer 37 during exposure. That is, the quick return mirror 12 is in the up state when the subject image is guided to the image sensor 19 and is in the down state when the subject image is guided to the optical viewfinder 16. When the quick return mirror 12 is in the up state, the subject image is guided to the image sensor 19 and is not guided to the optical viewfinder 16 side.

Reference numeral 13 denotes a focusing screen. A photographer observes the focusing screen 13 through a pentaprism 14 and a viewfinder (optical viewfinder) 16 so that the focus and composition of the optical image of the subject obtained through the lens unit 100 can be confirmed. It becomes possible. The pentaprism 14 is an optical system that refracts the subject image formed on the focusing screen 13 so that the photographer can observe it as an erect image. Therefore, if it is such, the pentamirror comprised by bonding a mirror may be sufficient.

  Reference numeral 15 denotes an AE (automatic exposure control) sensor that measures the luminance of the subject light. Specifically, as shown in FIG. 1, a subject image that is arranged in the vicinity of the pentaprism 14 and is formed on the focusing screen 13 is measured through the pentaprism 14.

  Reference numeral 17 denotes a focal plane shutter that can appropriately control the exposure time of the image sensor 19 under the control of the microcomputer 37.

  An optical filter 18 is generally composed of an optical low-pass filter or the like, and cuts high-frequency components of light entering from the focal plane shutter 17 and guides subject light to the image sensor 19.

  As the image sensor 19, a CCD, a CMOS sensor, or the like is generally used, and an image signal is generated by photoelectrically converting a subject image formed through the lens unit 100.

  Reference numeral 20 denotes an A / D conversion circuit that converts an analog signal converted into an electric signal by the image sensor 19 into a digital signal.

  An image processing circuit 21 performs filter processing, color conversion processing, and gamma / knee processing on the image data converted into a digital signal by the A / D conversion circuit 20 and outputs the processed data to the memory controller 27. The image processing circuit 21 also includes a D / A conversion circuit, and converts the image data converted into a digital signal by the A / D conversion circuit 20 and the image data input from the memory controller 27 into an analog signal. To do. The analog image signal can be output to the liquid crystal display unit 23 via the liquid crystal driving circuit 22. Image processing and display processing by these image processing circuits 21 are switched by the microcomputer 37. Further, the microcomputer 37 performs white balance adjustment based on the color balance information of the photographed image.

  A liquid crystal display unit 23 includes a half mirror between a backlight light source 25 and a liquid crystal panel (liquid crystal unit), which will be described later, and is used for both reflection and transmission that can be visually recognized by external light even when the backlight light source 25 is turned off. LCD.

  Reference numeral 24 denotes a backlight control circuit, which controls the amount of light from the backlight light source 25 according to instructions from the microcomputer 37.

  The memory controller 27 stores unprocessed image data input from the image processing circuit 21 in the buffer memory 26 and stores image processed image data in the memory 28. Conversely, image data is fetched from the buffer memory 26 or the memory 28 and output to the image processing circuit 21. The memory controller 27 stores image data sent via an external interface 29 such as USB (Universal Serial Bus) or IEEE (Institute of Electrical and Electronics Engineers) in the memory 28, or conversely. It is also possible to output the image data stored in the external via the external interface 29. In addition, the memory 28 may be configured to be detachable, and is illustrated as a detachable memory in FIG. Specifically, a compact flash (registered trademark) memory can be used.

  Reference numeral 30 is an AC power supply unit, and 31 is a secondary battery unit. The secondary battery unit includes a NiCd battery, a NiMH battery, a Li-ion battery, and the like. Reference numeral 34 denotes a power supply control unit which turns on / off the power supply according to an instruction from the microcomputer 37. In addition, the microcomputer 37 is notified of information on the current power supply state detected by the power supply state detection circuit 33 and information on the current power supply type detected by the power supply type detection circuit 32.

  Reference numeral 35 denotes a shutter control circuit, through which the microcomputer 37 controls the focal plane shutter 17.

  Reference numeral 36 denotes a user operation detection circuit through which a user instruction is notified to the microcomputer 37.

  2 and 3 are external views of the lens unit 100 and the digital camera main body 200, and portions common to FIG. 1 are denoted by the same symbols.

  Reference numeral 201 denotes a release button. By pressing the release button 201 halfway, the brightness of the subject is measured and the focus is adjusted.

  Further, when the release button 201 is fully pressed, the shutter is released and an image is taken. The internal operation of the camera by pressing the release button 201 will be described later.

  Reference numeral 202 denotes a mode dial for setting the camera mode. The user can set shooting modes such as a sports mode and a landscape mode by turning the mode dial 202.

  Reference numeral 203 denotes an electronic dial. The user sets values such as a shutter speed and an aperture value by turning the electronic dial.

  Reference numeral 204 denotes a cross key and a selection button. When selecting setting contents, thumbnail images, and the like displayed on the liquid crystal display unit 23, the selection range moves in the horizontal direction by pressing the key 204a, and the selection range in the vertical direction by pressing the key 204b. Moves. In addition, the selected content can be set by pressing the selection button 204c at the selected location.

  Reference numeral 205 denotes a power switch. Turning the power switch turns the power on and off.

  Reference numeral 206 denotes a switch group for performing various settings. These switch groups include a playback instruction button for displaying an image stored in a recording medium inside and outside the camera on the liquid crystal display unit 23, a setting screen display instruction button for displaying various setting screens on the liquid crystal display unit 23, and the like. There is. By pressing these switches, the user can display a screen for performing various settings, check a captured image, and the like.

  As shown in FIG. 3, the viewfinder 16 and the liquid crystal display unit 23 are both disposed on the back surface of the digital camera body 200.

(Operation of digital camera)
Next, the overall operation of the digital camera of this embodiment will be described using the flowchart of FIG.

  First, in step S10, the liquid crystal drive circuit 22 is operated. Then, it is determined whether or not it is necessary to display image data or various setting screens on the liquid crystal display unit 23. If it is determined that display is necessary, the process proceeds to step S11. Proceed to step S13.

  In step S11, external light (viewfinder reverse incident light) incident on the camera via the finder 16 is measured to determine the amount of backlight light. Details of the determination method will be described later.

In step S12, the image data written in the memory 28 or an external storage medium is displayed on the liquid crystal display unit 23 . When performing live view display, the quick return mirror 12 is in the mirror-up state, the focal plane shutter 17 is in the open state, and the aperture is in the open state according to an instruction from the microcomputer 37. Thereafter, an image signal is generated by the image sensor 19 at a fixed period, and the generated analog signal is converted into a digital signal by the A / D conversion circuit 20. Image processing is performed on the digital signal by the image processing circuit 21 based on the set ISO value. Then, the image data subjected to the image processing is displayed on the liquid crystal display unit 23. After the display, the backlight is turned on with the amount of light determined in step S11.

  In step S13, if the release button 201 is pressed and it is determined that there is a shooting instruction, the process proceeds to step S14. If there is no shooting instruction, the process proceeds to step S115.

  In step S14, the subject is photographed. The basic flow of shooting is to first measure the brightness of the subject using the AE sensor 15 by pressing the release button 201 halfway, and calculate the shutter time and aperture value. Next, the defocus amount of the subject is detected using the AF sensor 11 and communicated with the lens unit 100 using the communication terminals 6 and 10 on the camera side and the lens unit side, respectively. Then, the lens system control circuit 4 uses the AF driving circuit 3 to drive the photographing lens 5 to the in-focus position.

  Thereafter, when the release button 201 is completely pressed, the quick return mirror 12 enters the mirror-up state, and the lens system control circuit 4 controls the aperture 1 to the calculated aperture value via the aperture drive circuit 2.

After that, exposure is started, and light from which a specific frequency component is cut by the optical filter 18 is received by the image sensor 19 to generate an image signal. The generated analog image signal is converted into a digital signal by the A / D conversion circuit 20, and image processing is performed by the image processing circuit 21 based on the set ISO value.

  The image data that has undergone image processing is temporarily written into the buffer memory 26 via the memory controller 27, and then written into the memory 28 or written to an external storage medium via the interface 29.

  In step S15, it is determined whether or not an instruction to end the display on the liquid crystal display unit 23 has been issued. When an instruction to end the display on the liquid crystal display unit 23 is given, the process proceeds to step S16, the display on the liquid crystal display unit 23 is ended, and the operation of the digital camera is ended. On the other hand, if no instruction to end the display on the liquid crystal display unit 23 is given in step S15, the process returns to step S13.

  Next, the operation in step S11 in FIG. 4 will be described using the flowchart in FIG. 5 and the table in FIG.

  In FIG. 5, in step S100, the quick return mirror 12 is mirrored up according to an instruction from the microcomputer 37 in order to measure only the light incident from the finder 16 disposed on the same plane as the liquid crystal display unit 23 by the photometric sensor 15. Put it in a state. By entering the mirror up state, it is possible to block light incident from the subject side.

  In step S101, light incident from the finder 16 is reflected by the click-up return mirror 12 in the mirror-up state via the pentaprism 14, and the reflected light passes through the pentaprism 14 again, and is an AE sensor 15 that is a photometric sensor. Measured by

  In step S101, light incident from the finder 16 is reflected by the click return mirror 12 in the mirror-up state via the pentaprism 14, and the reflected light is measured by the AE sensor 15 that is a photometric sensor.

  In step S102, using the result of step S101, the amount of light of the backlight is changed in four steps (stepwise) as shown in the table of FIG. 6, for example.

  In FIG. 6, threshold values 1 to 3 represent threshold values of luminance values, and have a relationship of threshold value 1 (luminance value 1)> threshold value 2 (luminance value 2)> threshold value 3 (luminance value 3). . The photometric result indicates the luminance value of light incident from the finder 16.

  The liquid crystal display unit 23 has poor visibility when strong external light is incident thereon. In addition, as described above, the liquid crystal display unit 23 has a property that it can be visually recognized by external light even when the backlight is turned off. Therefore, in the present embodiment, when strong external light is incident on the liquid crystal display unit 23, the backlight is weaker and the visibility is improved. Therefore, the backlight source 25 is turned off or dimmed.

  Specifically, when the photometric result shows a high luminance value in step 101, it can be seen that strong light is incident on the finder 16. In this case, since the finder 16 is on the same side as the liquid crystal display unit 23 of the digital camera body 100, the fact that strong light is incident on the finder 16 means that strong light is also incident on the liquid crystal display unit 23. Can be considered. Therefore, if the photometric result in step S101 is higher than the threshold value 1, it is determined that strong light is incident on the liquid crystal display unit 23, the backlight source 25 is turned off, and the visibility is improved.

  Similarly, when the photometric result in step S101 is higher than the threshold value 2 and lower than or equal to the threshold value 1, the light quantity of the backlight light source 25 is reduced to a small value to improve the visibility.

  If the photometric result in step S101 is higher than the threshold 3 and lower than the threshold 2, the light quantity of the backlight source 25 is set to an intermediate value to improve visibility.

  Furthermore, when the photometric result in step S101 is equal to or less than the threshold value 3, it is considered that only weak light is incident on the liquid crystal display unit 23. Therefore, the light amount of the backlight light source 25 is increased to make it easier to see. .

  As described above, in the present embodiment, by measuring the light incident from the finder, it is determined how much light is incident on the liquid crystal display unit, and the backlight according to the intensity of the light. The light intensity is adjusted. That is, when strong light is incident on the liquid crystal display unit, the light amount of the backlight is reduced, and when only weak light is incident on the liquid crystal display unit, the light amount of the backlight is increased. By doing in this way, it becomes possible to improve the visibility of the liquid crystal display part arrange | positioned at the back surface of a digital camera.

  In the present embodiment, the liquid crystal display device including the liquid crystal display unit 23 and the backlight 25 is described as an example of the display unit. However, the present invention is not limited to this. For example, if a device such as an organic EL element that emits light by itself is used as the display means, the amount of light emitted from the element is changed according to the photometric result of reverse incident light, as in this embodiment. Visibility can be improved.

(Other embodiments)
The object of each embodiment is also achieved by the following method. That is, a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded is supplied to the system or apparatus. Then, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but the present invention includes the following cases. That is, based on the instruction of the program code, an operating system (OS) running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  Furthermore, the following cases are also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion card or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the above storage medium, the storage medium stores program codes corresponding to the procedure described above.

It is a block diagram which shows the structure of the digital camera of one Embodiment. It is a figure which shows the external appearance of the digital camera of one Embodiment. It is a figure which shows the external appearance of the digital camera of one Embodiment. It is a flowchart which shows the whole operation | movement of a digital camera. It is a flowchart which shows the flow of adjustment operation | movement of a backlight light quantity. It is a figure which shows the relationship between the intensity of external light, and the light quantity of a backlight.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diaphragm 2 Diaphragm drive circuit 3 AF drive circuit 4 Lens system control circuit 5 Shooting lens 6 Communication terminal 10 Communication terminal 11 AF sensor 12 Quick return mirror 13 Focusing screen 14 Penta prism 15 AE sensor 16 Finder 17 Focal plane shutter 18 Optical filter 19 Image sensor 20 A / D conversion circuit 21 Image processing circuit 22 Liquid crystal drive circuit 23 Liquid crystal display unit 24 Backlight control circuit 25 Backlight light source 26 Buffer memory 27 Memory controller 28 Memory 29 Interface 30 AC power supply unit 31 Secondary battery unit 32 Power supply Type detection circuit 33 Power supply state detection circuit 34 Power supply control circuit 35 Shutter control circuit 36 User operation detection circuit 37 Microcomputer

Claims (5)

An imaging means for generating image signals from the Utsushitai image,
Via an optical system for refracting the erect, the object image formed on the focusing screen between a first position for guiding the optical viewfinder, and a second position for guiding the subject image to the imaging unit A movable mirror ,
Photometric means for measuring light incident through the optical system;
In a state where the front you error is moved to the second position, the viewfinder reverse input light incident from the optical viewfinder metering by said photometry means, in accordance with the result of photometry, the image generated by the image pickup means imaging apparatus characterized by having a <br/> and control means for controlling a light amount of the display means for displaying the signal. Wherein the display means comprises a liquid crystal unit for displaying an image signal, a light source for illuminating the liquid crystal unit from the rear,
It said control means, the image pickup apparatus according to claim 1, wherein the photometric result and controls so as to turn off the pre-Symbol light source is greater than a predetermined threshold value. The control means, in response to the result of photometry, the image pickup apparatus according to claim 1 or 2, wherein the controller controls so as to stepwise vary the light intensity of said display means. An imaging means for generating an image signal from the subject image , a first position for guiding the subject image formed on the focusing screen to an optical viewfinder via an optical system for refracting an erect image , and the subject image A control method for controlling an image pickup apparatus having a mirror movable to a second position for guiding to an image pickup means and a photometry means for measuring light incident through the optical system,
In a state where the front you error is moved to the second position, the viewfinder reverse input light incident from the optical viewfinder metering by said photometry means, in accordance with the result of photometry, the image generated by the image pickup means control method for an imaging apparatus characterized by comprising the step of controlling the light amount of the display means for displaying the signal. An imaging means for generating an image signal from the subject image, a first position for guiding the subject image formed on the focusing screen to an optical viewfinder via an optical system for refracting an erect image, and the subject image Causing a computer to execute a control method for controlling an image pickup apparatus having a mirror movable to a second position for guiding to an image pickup means, and a photometry means for measuring light incident through the optical system. a Help program,
With the mirror moved to the second position, finder reverse incident light incident from the optical finder is measured by the photometric means, and an image signal generated by the imaging means is obtained according to the photometric result. A program comprising a step of controlling a light amount of a display means for displaying .

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