JP5803055B2 - Electronic camera - Google Patents

Description

  The present invention relates to an electronic camera.

Some electronic cameras such as compact digital cameras display an image captured by an image sensor in real time (hereinafter referred to as “through image display”) on a liquid crystal monitor for confirmation before shooting. Some electronic cameras having such a configuration also serve as an image sensor provided for imaging for photometry for exposure control (see, for example, Patent Document 1).
In recent years, electronic cameras tend to have high performance and multiple functions, and the number of functions installed tends to increase.

JP 2009-49927 A JP 2004-266362 A

  In an electronic camera provided with a through image analysis processing function that is multi-functionalized such as high image quality, advanced image correction, and motion detection, the amount of program related to the through image display processing increases as the function increases. In the control based on the timing chart after turning on the power shown in FIG. 3, it is possible to take a picture even though the imaging can be started after the power is turned on at time T1 and before reaching time T2A. The timing at which the image can be confirmed as a through image is after time T4. That is, since the time for loading and initializing the through image display program indicated as the period from time T2 to time T3 becomes longer, preparation for starting the processing by the through image display program is not completed. The timing for starting the exposure control process is delayed. For this reason, the exposure control process starts at time T3, which may be a bottleneck for shortening the time from when the power is turned on to when shooting is possible.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electronic camera that can shorten the time from when the power is turned on to when shooting is possible.

In order to solve the above-described problem, the present invention is an electronic camera that sequentially displays images repeatedly captured by an image sensor on a display unit, an exposure control unit that performs an exposure control process based on the image, and the image It performed a display image generation unit that performs image generation processing for generating a display image to be displayed on said display unit based, said exposure control processing by the exposure control unit, and said image generation processing by the pre-Symbol display image generating section A control unit that performs the image generation processing performed by the display image generation unit and the exposure control processing performed by the exposure control unit in parallel, and the exposure control to start the exposure control process performed by the parts, together to start the exposure control process is the initialization process of the image generation processing of the display image generating unit from the start to the exposure control processing is completed , The imaging device is an electronic camera, characterized in that for supplying a signal to be output by the imaging in the exposure control unit.

  According to the present invention, it is possible to shorten the time from when the power is turned on to when shooting is possible.

It is a block diagram which shows the structure of the electronic camera by one Embodiment of this invention. 6 is a timing chart showing an operation at the time of power activation of the electronic camera according to the embodiment. It is a timing chart which shows the operation | movement at the time of the power activation of the conventional electronic camera.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of the electronic camera according to the present embodiment.
An electronic camera 1 shown in FIG. 1 includes a power button 11, an operation member 12, an auxiliary storage device 13, a memory unit 14, a display control unit 15, a monitor unit 16, an image compression unit 17, a storage medium 18, and an image processing unit 19. , A lens barrel 21, an image sensor 22, an analog / digital (A / D) converter 23, an exposure gain setting unit 24, a lens drive controller 25, and a controller 30.

The power button 11 is a power switch for controlling power-on of the electronic camera 1. The power button 11 detects an operation for instructing power-on performed by the user, and supplies the detected power control instruction information to the control unit 30 as a control signal.
The operation member 12 detects a user operation and supplies the detected operation information to the control unit 30 as a control signal. The operation member 12 includes, for example, a release switch and a setting button.
The auxiliary storage unit 13 is a non-volatile storage unit that stores a program for operating the control unit 30, image data captured and generated, information such as various settings and imaging conditions input by the user. The programs stored in the auxiliary storage unit 13 include initial startup control, imaging control, lens control, exposure control, live view control, other GUI (Graphical User Interface) programs, and the like divided for each region. The program stored in this program storage area may be compressed and stored according to the situation.
The memory unit 14 is a temporary information storage area used for the control process of the control unit 30, and includes a program storage area that loads and executes a program stored in the auxiliary storage unit 13, for example. The memory unit 14 is referred to when the control unit 30 executes the program. The memory unit 14 may include a captured image storage area that stores an image signal output from the image sensor 22, a setting information storage area that stores image data generated in accordance with the image signal, and the like.

For example, the display control unit 15 performs display control such as turning on / off or brightness adjustment of the monitor unit 16 and processing for causing the monitor unit 16 to display image data supplied from the image processing unit 19.
The monitor unit 16 displays the supplied image data. The monitor unit 16 is configured by, for example, a liquid crystal display (LCD).
The image compression unit 17 performs compression / decompression processing of the captured image stored in the memory unit 14 and stores the processing result in the memory unit 14 again.
The storage medium 18 is, for example, a storage medium (such as a memory card) that can be inserted into and removed from the main body, and stores image data generated by the control unit 30.

The image processing unit 19 includes an AE evaluation value calculation circuit for exposure control in addition to a circuit that converts the Bayer output from the image sensor 22 into a monitor display image.
The image processing unit 19 is supplied with the image signal detected by the imaging unit 22 via the A / D conversion unit 23, and performs conversion processing necessary for display on the monitor unit 16, recording in the memory unit 14, and the like. An evaluation value calculation process is performed.

The lens barrel 21 includes an optical element that adjusts the output of light to the image sensor 22 and a structure that protects the optical element and the like.
The imaging element 22 is a light receiving element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) sensor, and converts the image output from the lens barrel 21 into an electrical signal to generate an analog image signal. Is output. An A / D conversion unit 23 and an exposure gain setting unit 24 are connected to the image sensor 22. Note that the imaging element 22 and the A / D conversion unit 23 and the exposure gain setting unit 24 described below are collectively referred to as an imaging unit.
The A / D converter 23 amplifies the image signal output from the image sensor 22 and converts it into a digital signal.
The exposure gain setting unit 24 changes the charge accumulation time of the image sensor 22 and the amplification amount of the A / D conversion unit 23 based on the control amount obtained by the AE control unit 36.
The lens drive control unit 25 drives the lens barrel 21 with an actuator such as a motor in accordance with a control signal from the control unit 30 to adjust the light output to the image sensor 22. The lens drive control unit 25 collects information on various sensors and encoders provided in the lens barrel 21 and notifies the control unit 30 of the information.

  The control unit 30 includes a CPU (Central Processing Unit) that controls the operation of each unit of the electronic camera 1 based on a program stored in the auxiliary storage unit 13. For example, the control unit 30 turns on the power of the electronic camera 1, controls the driving of the lens barrel 21 via the lens driving control unit 25, and sets the exposure gain according to the operation information from the user input to the operating member 12. Based on the drive control of the image sensor 22 via the unit 24, the display control of the monitor unit 16 via the display controller 15, the photographing process of the subject detected by the image sensor 22, and the image signal photographed via the image processor 19 Controls creation of image data.

The control unit 30 includes a basic control unit 31, an input / output processing unit 32, a lens control unit 33, an imaging control unit 34, an exposure (AE) control unit 36, an image processing control unit 37, a display control unit 38, and a recording control unit 39. Prepare.
The basic control unit 31 generates a control signal for controlling the operation of each unit of the electronic camera 1 and supplies the generated control signal to each unit to perform necessary control. The basic control unit performs power supply control in the electronic camera 1, for example. Based on the instruction detected by the power button 11, the electronic camera 1 is changed to a state capable of photographing, or the transition from the state capable of photographing to a standby state where no photographing is performed (standby state) is controlled.
The input / output processing unit 32 determines a detection signal based on a user operation detected on the operation member and supplies the detection signal to the basic control unit 31.
The lens control unit 33 controls the lens barrel 21 to a state required for photographing based on control from each unit. When the imaging control start command is input from the basic control unit 31, the lens control unit 33 drives the lens barrel 21 so that it can shoot. The lens control unit 33 controls focusing, exposure control, zooming, and the like of the lens barrel 21 via the lens drive control unit 25.
The imaging control unit 34 responds to each unit in response to a control signal such as an imaging process start command or an imaging process end command for controlling imaging processing based on a user operation input being input from the operation member 12. Output necessary control signals. When an imaging processing start command is input, the imaging control unit 34 drives the lens barrel 21 via the lens control unit 33 and performs imaging processing for generating image data.

The exposure (AE) control unit 36 adjusts the luminance indicated by the AE evaluation value detected via the image processing unit 19 based on the image signal output from the image sensor 22 to a predetermined desired range. The exposure gain setting unit 24 is controlled.
The image processing control unit 37 performs processing for generating image data by performing signal processing such as demosaicing, noise reduction, and resolution conversion based on the image signal detected by the image sensor 22, and the generated image data as a memory unit. 14 is performed via the image processing unit 19.
The display control unit 38 reads the image data generated by the image processing unit 19 and stored in the memory unit 14 at regular time intervals, and outputs the read image data to the monitor unit 16 in real time. Here, the fixed time interval is, for example, 1/60 seconds. In this case, 60 frames of image data per second is displayed on the monitor unit 16 by the display control unit 38 as a through image, and the image compression unit 17 preliminarily displays the image data. It is compressed at a predetermined compression rate and recorded in the memory unit 14 as a moving image.
The recording control unit 39 temporarily stores the image signal captured by the imaging element 22 in the memory unit 14 and stores the image signal from the memory unit 14 in the auxiliary storage unit 13 or the storage medium 18.

FIG. 2 is a timing chart showing the operation when the electronic camera is powered on.
In the figure, the vertical axis indicates, in order from the top, initial program load processing, OS startup processing, imaging lens barrel initialization processing, exposure control unit initialization processing, exposure control unit program load processing, initial exposure control processing, and through image control. A program load process, a through image control unit initialization process, a monitor display image creation process, and other program load processes such as a GUI are shown.
The horizontal axis indicates the passage of time starting from the point in time when the power button 11 is operated and a transition instruction from the standby state to the power-on state is detected.
Each process indicates a state in which a period indicated by a pulse width represented by positive logic is continuously processed. That is, the “H” state is a state in which each process is being executed, and the “L” state is a state in which each process is paused.

The initial program load process, the OS startup process, the exposure control unit program load process, the live view control program load process, and other program load processes such as GUI are stored in the auxiliary storage unit 13 by the basic control unit 31. Is recorded in a storage area provided in the memory unit 14 to make the program executable.
The imaging lens barrel initialization process is a process in which the lens control unit 33 controls the lens barrel 21 via the lens drive control unit 25.
The exposure control unit initialization process is a process for enabling control by an AE control unit 36 to be described later.
The initial exposure control process is a process for optimizing the exposure by the AE control unit 36 based on the image signal detected by the image sensor 22.
The through image control initialization process is a process for enabling control by an image processing control unit 37 and a display control unit 38 to be described later.
The monitor display image creation process is performed by the image processing control unit 37 and the display control unit 38 to create an image signal picked up by the image sensor 22 as image data for monitor display via the image processing unit 19. In this process, the created monitor display image data is displayed on the monitor unit 16 via the display control unit 38.

The state before time T1 indicates a standby state in which all the processes shown in FIG. 2 are not executed.
In the standby state, as in the power-on detection process in the basic control unit 31, a minimum process necessary for performing the power activation process from the standby state is performed, but the illustration is omitted.

First, the basic control unit 31 detects that the power button 11 has been operated (time T1).
When detecting that the power button 11 has been operated, the basic control unit 31 starts an initial program loading process for loading an initial program (time t11).
In addition, when the initial program loading process is completed, the basic control unit 31 starts the operating system in accordance with the loaded initial program (time t12). When the basic control unit 31 transitions to a state where the activation of the operating system is completed (time t13), the basic control unit 31 starts the imaging control unit initialization process by the imaging control unit 34 and the lens control unit initialization process by the lens control unit 33. . In the imaging control unit initialization process, the imaging control unit 34 performs a process of setting the imaging element 22, the A / D conversion unit 23, and the exposure gain setting unit 24 in a state where imaging is possible. Further, in the lens control unit initialization process, the lens control unit 33 performs a process for making the lens drive control unit 25 ready for photographing. Then, the imaging control unit initialization process and the lens control unit initialization process are each completed by time t14.

Further, the basic control unit 31 starts a process for displaying a through image in parallel with the imaging control unit initialization process and the lens control unit initialization process being processed. First, the exposure control program loading process to be loaded by the exposure control program is started (time T2 (t21)).
In addition, when the exposure control program loading process is completed, the basic control unit 31 starts the exposure control unit initialization process by the exposure control unit 34 (time t22).
Then, when the exposure control unit initialization process is completed, the exposure control unit 34 starts the initial exposure control process (time T3A (t23)). In the initial exposure control process, the operation of the AE evaluation value calculation circuit in the image processing unit 19 is started, and the exposure is set to an appropriate value so that the value of the signal captured by the image sensor 22 falls within a predetermined desired range. The process of converging so as to become is shown (refer to Patent Document 2 for detailed processing, for example). Then, the exposure control unit 34 completes the initial exposure control process by time t24. In the period from time t23 to time t24, the signal output from the image sensor 22 is used only in the initial exposure control process.

As shown in FIG. 2, it is assumed that the imaging control unit initialization process and the lens control unit initialization process are completed (time t14) during a period from time t22 to time t23. Already at time t14, the imaging unit including the imaging device 22 and the optical system up to the imaging device 22 are initialized and are ready to start imaging. Therefore, the basic control unit 31 starts loading the live view image processing program in parallel with the exposure control unit initialization process or the initial exposure control process being processed (time T2A (t31)). In parallel with the above processing, the monitor display image creation processing program is loaded.
In addition, when the loading process of the through image processing program is completed, the basic control unit 31 starts the through image control unit initialization process by the image processing control unit 37 (time t32). Then, the image processing control unit 37 completes the through image control unit initialization processing by time t33.
When the through image control unit initialization process is completed, the display control unit 38 starts the monitor image creation process (time t33).

  When the monitor image creation process is started at time t33 and the initial exposure control process is completed at time t24, a through image display with proper exposure can be performed, and the generated image with proper exposure is displayed in real time. Are displayed on the image monitor unit 16 (time T4).

As shown in the present embodiment, the initial program load process, the OS activation process, and the imaging lens barrel initialization process are sequentially processed as a series of processes. Further, the exposure control program loading process, the exposure control unit initialization process, and the initial exposure control process are sequentially processed as a series of processes. Furthermore, the through image control program loading process and the through image control unit initialization process are sequentially performed. The series of processing described above, monitor display image creation processing, and other program loading processing such as GUI can be processed in parallel.
In this way, by dividing the exposure control program and the monitor display image creation program and performing loading and initialization in parallel, the time until a through image with proper exposure is displayed is optimized, and shooting is performed. The time until it becomes possible can be shortened.

In the electronic camera 1 according to the embodiment of the present invention, images repeatedly captured by the image sensor 22 are sequentially displayed on the display unit 16. The AE control unit 36 (exposure control unit) performs exposure control based on the image. The image processing unit 19 (display image generation unit) generates a display image to be displayed on the display unit 16 based on the image. The basic control unit 31 (order control unit) starts exposure control by the AE control unit 36 and performs order control in which generation of the display image by the image processing unit 19 is started after the exposure control is started.
Thereby, it is possible to shorten the time from when the power is turned on to when shooting is possible.

Further, in the present embodiment, the basic control unit 31 causes the sequence control for the AE control unit 36 and the image processing unit 19 to be performed as a startup process performed after power-on.
As a result, the basic control unit 31 can reduce the time from when the power is turned on to when shooting is possible by performing sequence control on the AE control unit 36 and the image processing unit 19.

  In the present embodiment, since the AE control unit 36 can perform exposure control in parallel with the generation of the display image performed by the image processing unit 19, the time from when the power is turned on to when shooting is possible can be shortened. Can do.

  Further, in the present embodiment, the basic control unit 31 can start generation of a display image by the image processing unit 19 while performing exposure control by the AE control unit 36, so that it is possible to shoot from power-on. The time until it can be shortened.

  In the present embodiment, the basic control unit 31 can perform the initialization process of the AE control unit 36 prior to the display image generation by the image processing unit 19, so that the process from the power-on to the shooting can be performed. Time can be shortened.

  In the present embodiment, the basic control unit 31 can perform the initialization process of the AE control unit 36 prior to the initialization process of the image processing unit 19, so that the process from when the power is turned on to when shooting is possible. Time can be shortened.

In the present embodiment, the auxiliary storage unit 13 (first storage unit) holds, in a nonvolatile manner, a program that causes the AE control unit 36 and the display image generation unit to function (information that allows the processing procedure to function). A program stored in the auxiliary storage unit 13 is written in the memory 14 (second storage unit). The basic control unit 31 stores a program (first information) that is stored in the auxiliary storage unit 13 and that causes the AE control unit 36 to function as a processing procedure in which the AE control unit 36 performs exposure control and sets the camera in a ready state. A program loading process (first process) stored in the memory unit 14 is provided. In addition, the basic control unit 31 stores a program (second information indicating a processing procedure) that is stored in the auxiliary storage unit 13 and that generates a display image that the image processing unit 19 displays on the monitor unit 16 based on the image. A program loading process (second process) stored in the memory unit 14 is provided. The program loading process for causing the AE control unit 36 to function is performed prior to the program loading process for generating the display image, independently of the program loading process for generating the display image.
As a result, the timing of loading processing of each processing program can be adjusted separately, so that the time from when the power is turned on to when shooting is possible can be shortened.

  In the present embodiment, the program execution process for causing the AE control unit 36 to function is performed in parallel with the program load process for generating the display image, and is started before the program load process for generating the display image. Thus, it is possible to shorten the time from when the power is turned on to when shooting is possible.

  In the present embodiment, the execution process of the program that causes the AE control unit 36 to function is an exposure control process for adjusting the exposure of the image that is performed before the image is displayed on the monitor unit 16 after the power is turned on. It is possible to shorten the time from when the power is turned on to when shooting is possible.

As mentioned above, although embodiment of this invention has been explained in full detail with reference to drawings, the concrete composition is not restricted to this embodiment.
The configuration shown in the present embodiment is not limited to a compact type electronic camera, but is an interchangeable lens type electronic camera that displays an image on a display unit such as a monitor unit, a portable video camera, and a portable terminal device with an electronic camera function. It is applicable to.

1 Electronic camera 16 Monitor unit (display unit)
19 Image processor (display image generator)
22 Image sensor 30 Control unit 31 Basic control unit (sequence control unit)
36 AE control unit (exposure control unit)

Claims (8)

An electronic camera that sequentially displays images repeatedly captured by an image sensor on a display unit,
An exposure control unit that performs an exposure control process based on the image;
A display image generation unit that performs an image generation process for generating a display image to be displayed on the display unit based on the image;
A control unit for causing said exposure control processing by the exposure control unit, and said image generation processing by the pre-Symbol Display image generating section,
With
The control unit performs the image generation process performed by the display image generation unit and the exposure control process performed by the exposure control unit in parallel, and starts the exposure control process by the exposure control unit A signal output by the imaging device during imaging until the exposure control process is completed and the initialization process of the image generation process of the display image generation unit is started after the exposure control process is started. Is supplied to the exposure control unit . The electronic camera according to claim 1,
The controller is
The exposure control processing by the exposure control unit, the initialization processing of the image generation processing by the display image generation unit, and the image generation processing are performed as startup processing performed after power-on. camera. The electronic camera according to claim 1 or 2 ,
The controller is
An electronic camera, wherein the image generation processing by the display image generation unit is started while the exposure control processing by the exposure control unit is performed. The electronic camera according to any one of claims 1 to 3 ,
The controller is
An electronic camera characterized in that initialization processing of the exposure control processing of the exposure control unit is performed prior to the image generation processing by the display image generation unit. The electronic camera according to any one of claims 1 to 4 ,
The controller is
An electronic camera, wherein the exposure control process initialization process of the exposure control unit is performed prior to the image generation process initialization process of the display image generation unit. An electronic camera according to any one of claims 1 to 5 ,
A first storage unit that nonvolatilely stores information indicating a processing procedure for causing the exposure control unit and the display image generation unit to function;
A second storage unit in which information indicating the processing procedure stored in the first storage unit is written;
The controller is
A first process for storing in the second storage unit first information stored in the first storage unit, the first information indicating a processing procedure in which the exposure control unit performs the exposure control process and sets the camera in a ready state;
Second information stored in the first storage unit that indicates a processing procedure for generating a display image to be displayed on the display unit based on the image by the display image generation unit is stored in the second storage unit. A second process;
With
The first process includes
The electronic camera, wherein the process is performed prior to the second process independently of the second process. The electronic camera according to claim 6 ,
Execution of the exposure control process based on the first information stored in the second storage unit by the first process,
The electronic camera is processed in parallel with the second processing. The electronic camera according to claim 6 or claim 7,
The first process includes
An electronic camera, which is performed after power is turned on and before the image is displayed on the display.

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