JP2018207428A - Imaging apparatus - Google Patents

Abstract

To provide an imaging apparatus that can suppress power consumption when a long time remote live view is continued, and that can mitigate temperature rise of a camera body.SOLUTION: An imaging apparatus that is used in a remote control system comprising an external instrument which displays live video transmitted, that comprises a first sensor and a second sensor, and that provides the live video to a user comprises: sensor switching means that switches between the sensors which receive subject light, according to an instruction of the user or a state of the imaging apparatus; live video developing means that develops the subject light received by the sensor to make the live video; and live video transmitting means that transmits the live video to the external instrument.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a remote live view function for displaying a live video from a camera on an external device, and relates to a technique for suppressing power consumption of an imaging apparatus when a remote live view is continued for a long time.

  There is a remote live view function in which an external device such as a PC or a smartphone is connected to a camera wirelessly or the like, and a live video from the camera is displayed on the external device. To use this function with a single-lens reflex camera, it was necessary to use a live view mode with mirror up.

  This function makes it possible to remotely control a single-lens reflex camera from a physically distant place, but when continuing a remote live view for a long time, power consumption is intense and the temperature of the camera body rises. . For this reason, there has been a problem that the image quality deteriorates when shooting.

  Patent Document 1 discloses a remote control system including an imaging device that uses a video obtained by an imaging device as a live view image and an external device that receives and displays the live view image from the imaging device. When the predetermined operation of the external device and the predetermined operation of the external device are not detected for a specified time, the data amount of the live view image transferred from the imaging device to the external device is reduced. A technique has been proposed in which when there is no operation between the external device and the imaging apparatus for a certain period of time, the live view screen is put into a wait state to reduce the communication amount and save power.

JP 2014-27338 A

  However, when user operations are frequently performed between the external device and the camera body and the live view screen cannot be put into the wait state, power is consumed intensively due to continuous operation for a long time, and the camera body generates heat. The image quality has deteriorated. For this reason, there has been a demand for a technique for saving power other than a method for putting communication in a wait state.

  An object of the present invention is to provide an imaging apparatus capable of suppressing power consumption when continuing a long-time remote live view and reducing a temperature rise of a camera body.

In order to achieve the above object, an imaging apparatus according to the present invention includes:
An imaging apparatus that is used in a remote control system including an external device that displays a transmitted live video, has first and second sensors, and provides the user with live video, the user's instructions, or the Sensor switching means for switching a sensor for receiving subject light in accordance with the state of the imaging device, live video developing means for developing the subject light received by the sensor into a live video, and sending the live video to the external device Live video transmission means for transmission.

  According to the imaging apparatus of the present invention, it is possible to suppress power consumption of the imaging apparatus when continuing a long-time remote live view, and to reduce the temperature rise of the camera body.

It is a block diagram which shows the structure of an example of the imaging device which concerns on embodiment of this invention. It is a flowchart for demonstrating operation | movement of the live image | video (henceforth live view) which operate | moves with an imaging device. It is explanatory drawing for displaying a remote live image | video with a portable terminal. It is a block diagram for demonstrating operation | movement of normal LV mode and simple LV mode. It is a figure which shows an example of the image displayed by normal LV mode and simple LV mode.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Remote control system)
Live video acquired by the imaging apparatus according to the embodiment of the present invention described below is transmitted from the imaging apparatus and displayed on an external device. An imaging apparatus used in such a remote control system has first and second sensors and provides a live video to the user. An electronic camera such as a digital still camera or a digital movie camera is used as the imaging device. Moreover, as an external device connected to such an electronic camera, for example, a personal computer, a portable terminal, or the like is used. In the following, an example in which an imaging apparatus is applied to an electronic camera and an external device that displays live video is applied to a portable terminal will be described as a preferred application example of the present invention.

(Imaging device)
FIG. 1 is a block diagram showing the configuration of an example of an imaging apparatus according to an embodiment of the present invention.

  The illustrated imaging apparatus is, for example, a digital camera (hereinafter simply referred to as a camera), and includes a camera body 100 and a lens unit 200. The lens unit 200 can be attached to and detached from the camera body 100, that is, can be exchanged.

  The lens unit 200 includes a lens 201 (imaging optical system). The lens 201 is composed of, for example, a plurality of lenses. Here, a single lens is shown for simplicity. The communication terminal 206 is a terminal for the lens unit 200 to communicate with the camera body 100.

  The communication terminal 206 is connected to the communication terminal 118 provided in the camera body 100 when the lens unit 200 is attached to the camera body 100. That is, the lens unit 200 communicates with the camera control unit 105 provided in the camera body 100 via the communication terminals 206 and 118.

  The lens unit 200 includes a lens system control circuit 205, and the lens system control circuit 205 drives and controls the diaphragm 202 via the diaphragm driving unit 204. Further, the lens system control circuit 205 moves the lens 201 along the optical axis via the focus driving unit 203 to displace the position thereof, thereby focusing.

  In the camera body 100, a main mirror 101 is disposed on the optical axis (also referred to as a photographing optical path) of the lens unit 200. The main mirror 101 can be rotated in accordance with the operating state of the camera, and is positioned obliquely with respect to the photographing optical path (indicated by a broken line in the drawing) when the subject is observed with the viewfinder. As a result, an optical image (subject image) incident from the lens unit 200 is guided to a finder optical system described later.

  The main mirror 101 is retracted from the photographing optical path when photographing and when displaying a live video (hereinafter, live view). As a result, the optical image incident from the lens unit 200 is guided to the image sensor 103 described later. In FIG. 1, the position when the main mirror is positioned on the photographing optical path is indicated by a solid block 101, and the position when the main mirror is retracted from the photographing optical path is indicated by a broken line block 101 '.

  A shutter 102 is disposed following the main mirror 101, and the shutter 102 controls the incidence of the optical image incident from the lens unit 200 on the imaging sensor 103. The shutter 102 is opened during shooting and live view. The shutter 102 is driven and controlled by the shutter control unit 115 under the control of the camera control unit 105.

  An imaging sensor 103 is arranged at the subsequent stage of the shutter 102, and for example, a CMOS sensor or a CCD sensor is used as the imaging sensor 103. The imaging sensor 103 obtains a final still image and moving image, is driven based on a timing signal output from the timing generator 116, and outputs an electrical signal (analog signal) corresponding to the optical image. Note that the timing generator 116 sends a timing signal for controlling a so-called electronic shutter to the imaging sensor 103 under the control of the camera control unit 105.

  The analog signal processing unit 104 samples and holds an analog signal that is an output of the image sensor 103, adds an analog gain, and then converts the analog signal into a digital signal by A / D conversion. The camera control unit 105 performs digital signal processing, which will be described later, on the digital signal output from the analog signal processing unit 104 to generate image data, and stores the image data in the memory 121 via the memory control unit 120. As illustrated, the camera control unit 105 includes a digital gain unit 106, an image processing unit 107, a photometric processing unit 113, and an AE (automatic exposure) sensor processing unit 124.

  The digital gain unit 106 adds a digital gain to the digital signal that is the output of the analog signal processing unit 104. Then, the digital gain unit 106 outputs a digital signal to which the digital gain is added to the image processing unit 107.

  The image processing unit 107 performs predetermined digital signal processing on the digital signal output from the digital gain unit 106. For example, the image processing unit 107 performs pixel interpolation processing, color conversion processing, imaging surface AF (contrast AF) evaluation value calculation, and photometric value calculation. The normal image quality developing means described in claim 8 is included in the image processing unit 107.

  The image display unit 119 is an image display device such as an LCD (liquid crystal display device) that displays information related to images and photographing. The image display unit 119 displays an image corresponding to the image data output from the image processing unit 107. In the live view operation, so-called through images are sequentially displayed on the image display unit 119.

  The operation unit 122 is an input unit that receives an operation from a user. The operation unit 122 includes an operation dial for setting the shutter speed, a shooting instruction button, a live view switching button, and various operation buttons. The operation unit 122 sends an input operation by the user to the camera control unit 105.

  A focus plate 109 is disposed above the main mirror 101. The focus plate 109 is disposed on the primary image forming surface of the lens unit 200, has a Fresnel lens (condenser lens) on its entrance surface, and forms an optical image (finder image) of the subject on the exit surface.

  The pentaprism 110 changes the finder optical path, and corrects the subject image formed on the exit surface of the focus plate 109 to an erect image. The eyepiece 111 can adjust the diopter according to the user's eyes when the user looks into the viewfinder. Here, an optical system constituted by the focus plate 109, the pentaprism 110, and the eyepiece lens 111 is called a finder optical system.

  A photometric sensor 112 is disposed in the vicinity of the pentaprism 110, and the photometric sensor 112 has a plurality of regions obtained by dividing an imaging region, and includes a plurality of photodiodes corresponding to these regions. The photometric sensor 112 detects the luminance of the subject image formed on the exit surface of the focusing plate 109 and sends it to the photometric processing unit 113.

  An AE (automatic exposure) sensor 123 is disposed in the vicinity of the pentaprism 110, and receives the subject image reflected from the main mirror 101 in a mirror-down state. The AE sensor 123 is a two-dimensional array sensor for photometry / focusing. The AE sensor 123 detects luminance information from the subject image, and performs automatic exposure correction by the digital gain unit 106 and focusing processing by imaging plane phase difference AF.

  In the simple live view mode (hereinafter referred to as simple LV mode), light is received by the AE sensor 123 as the second sensor, passes through various image processing, is simply developed by the AE sensor processing unit 124, and is displayed on the screen display unit 301 of the mobile terminal 300. (Remote Live View). The simple development is performed by a simple image quality developing unit included in the AE sensor processing unit 124. In the simple LV mode, since the AE sensor 123 having a small number of pixels is used and the AF sensor 117 is not operated, the power consumption can be greatly reduced as compared with the normal live view mode (hereinafter referred to as the normal LV mode).

  In the simplified LV mode, the color information is omitted and the image is simply developed using only the luminance signal to change to a black and white image, or noise reduction processing and digital gain processing are omitted for the luminance signal and color signal. Simple development can further reduce power consumption.

  The image data captured from the AE sensor 123 is processed by the AE sensor processing unit 124, sent to the external output 126, and displayed on the image display unit 301 of the mobile terminal 300.

  The photometric processing unit 113 performs accumulation driving and reading driving at a predetermined interval (that is, photometric timing) with respect to the photometric sensor 112, and measures a time-series change of the photometric value (that is, light amount).

  The AF sensor 117 outputs a defocus amount corresponding to the shift amount of the pair of images to the camera control unit 105 by the imaging surface phase difference AF. The camera control unit 105 determines the lens driving amount and the driving direction based on the imaging surface AF evaluation value obtained by the image processing unit 107 or the defocus amount obtained by the AF sensor 117.

  The camera control unit 105 sends the lens driving amount and driving direction to the lens system control circuit 205 via the communication terminals 118 and 206. The lens system control circuit 205 drives the lens 201 to the optical axis by the focus driving unit 203 according to the lens driving amount and the driving direction. The camera control unit 105 is a microcomputer composed of a CPU, a ROM, and a RAM, and controls the entire camera by executing a program stored in the ROM.

  FIG. 2 is a flowchart for explaining the operation of a live video (hereinafter referred to as a live view) operating on the imaging apparatus.

  In order to receive the subject image incident through the lens unit 200 with the imaging sensor 103, the main mirror is mirrored 101 '(step S201).

  Subsequently, normal LV development is performed on the subject image received from the image sensor 103 by the normal image quality developing means (step S202).

  The normal LV display still image developed by the normal image quality developing means is sent to the external output 126 and displayed on the image display unit 301 of the portable terminal 300 (step S203).

  Next, it is determined using the warning state flag whether the image sensor 103 operates normally (step S204). The warning state flag is Yes when the image quality is deteriorated by image reading from the image sensor 103, and is No when the image quality is not lowered.

  As a first example in which the warning state flag is Yes, the imaging sensor 103 may exceed a certain temperature. The image sensor 103 is monitored using the temperature sensor 125. When the image sensor 103 rises in temperature and exceeds a certain temperature, the warning state flag is set to Yes. When the temperature of the image sensor 103 rises, heat-derived noise increases in the color signal and luminance signal output from the image sensor 103, so that the image quality deteriorates when the user takes a still image. In order to avoid the deterioration of the image quality, the live image operation mode is switched to the simple LV mode, the image sensor 103 is rested and the temperature of the image sensor 103 is lowered, thereby realizing power saving and image quality during still image shooting. Degradation can be avoided.

  As a second example in which the warning state flag becomes Yes, there is a case where the time continuously displayed in the normal LV mode exceeds a certain time. When the normal LV mode is continuously displayed for a predetermined time or longer, the warning state flag is set to Yes. Note that the temperature sensor 125 may be omitted when the determination is based only on the continuous display time.

  Next, if the warning state flag is No, the process returns to step S202, and normal LV development is performed by the normal image quality developing means on the subject image received during the next shutter speed. If the warning state flag is Yes, the main mirror is mirrored down 101, and the sensor for receiving light is changed (step S205).

  The subject image incident through the lens unit 200 after being mirrored down is reflected by the main mirror 101 and received by the AE sensor 123. The received subject image is subjected to simple LV development by the simple developing means (step S206), transmitted to the external output 126, and displayed on the display screen 301 of the portable terminal 300 (step S207).

  Subsequently, the warning state flag is determined (step S208). If the warning state flag is Yes, the simple LV development is continued. If the warning state flag is No, the process returns to step S201 to switch to the normal LV development.

  The warning status flag may be returned to No when it is detected that the temperature of the image sensor 103 has decreased, or when a certain period of time has elapsed since the start of the simple LV development mode.

  FIG. 3 is an explanatory diagram when a remote live video is displayed on the image display unit 301 of the mobile terminal 300.

  The user activates an application that displays a remote live video on the mobile terminal 300, and switches between the normal LV mode and the simple LV mode on the operation screen of the application. The switching operation depends on an operation menu prepared by the application, and uses the touch panel or the button unit 302 of the mobile terminal 300. The mobile terminal 300 and the camera body 100 are connected to the external output 303 of the mobile terminal 300 and the external output 126 of the camera body 100 via a wireless LAN.

  FIG. 4 is a block diagram for explaining operations in the normal LV mode and the simple LV mode.

  In the normal LV mode, the subject 401 is photographed with the main mirror in the mirror up 101 'state. Subject light obtained from the subject 401 passes through the lens unit 200 and is received by the imaging sensor 103. The shooting data is transferred to the mobile terminal 300 via the wireless network and displayed on the screen display unit 301 of the mobile terminal 300.

  On the other hand, in the simple LV mode, the subject 401 is photographed with the main mirror in the mirror down 101 state. The photographed subject light passes through the lens unit 200 attached to the camera body 100, is reflected by the main mirror 101, and is received by the AE sensor 123. The shooting data is transferred to the mobile terminal 300 via the wireless network and displayed on the screen display unit 301 of the mobile terminal 300.

  FIG. 5 shows an example of images displayed in the normal LV mode and the simple LV mode.

  An image in the normal LV mode is an image received by the image sensor 103, which is normally developed by a normal image developing unit and then sent to the external output 126 and displayed on the display screen 301 of the portable terminal 300. A high-quality image equivalent to when shooting The image in the simple LV mode is an image received by the AE sensor 123, simply developed by the simple image developing means, sent to the external output 126, and displayed on the display screen 301 of the portable terminal 300. Through. Since image correction processing such as exposure correction and peripheral light amount correction is not applied, it does not exactly match the image when the still image was taken, but the remote live view image can be displayed at the same timing as the normal LV mode. , So that the user does not miss a photo opportunity.

  The update timing of the remote live video will be described.

  In the normal LV mode, a plurality of still images are captured from the image sensor 103 at a frame rate (fps) of 60 fps, 50 fps, 30 fps, 25 fps, 24 fps per second, and developed, so that the quality is smooth. A video can be displayed.

  On the other hand, in the simple LV mode, a still image is captured from the AE sensor 123 having a small number of pixels, and development is performed by omitting part or all of the image correction processing. Smooth videos can be displayed while resting.

  In the present embodiment, the operation mode of the remote live view has been described in detail. In the case of shooting a still image, shooting is started by operating the operation button 302 while checking the live video displayed on the display screen 301. The description of the still image shooting sequence is omitted.

  Although the remote live view has been described in detail in the present embodiment, it can also be applied to the image display unit 119 of the imaging apparatus main body 100. When displaying on the image display unit 119, it is only necessary to change the transmission destination of the normal LV display and the simple LV display to the image display unit 119.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to these embodiment, Various forms of the range which does not deviate from the summary of this invention are also contained in this invention. . For example, in the imaging device and the remote control system according to the present invention, the live video transmission unit has been described on the assumption of a wireless network, but may be a wired network.

100 camera body, 101 main mirror, 102 shutter, 103 image sensor,
104 analog signal processing unit, 105 camera control unit, 106 digital gain unit,
107 image processing unit, 109 focusing plate, 110 penta prism,
112 photometric sensors, 113 photometric processing units, 118 communication terminals, 119 image display units,
120 memory control unit, 121 memory, 122 operation unit, 200 lens unit,
123 AE sensor, 124 AE sensor processing unit, 125 temperature sensor,
126 external output, 300 mobile terminal, 301 screen display unit of mobile terminal,
401 Subject

Claims (11)

An imaging apparatus that is used in a remote control system including an external device that displays a transmitted live video, has first and second sensors, and provides a live video to a user,
Sensor switching means for switching a sensor for receiving subject light in accordance with a user instruction or the state of the imaging device;
Live video development means for developing subject light received by the sensor into a live video,
Live video transmission means for transmitting the live video to the external device;
An imaging apparatus comprising:   2. The first sensor according to claim 1, wherein the first sensor obtains a final still image and a moving image, and the second sensor is a two-dimensional array sensor for photometry or focusing. Imaging device.   The imaging apparatus according to claim 1, wherein the live video developing unit develops subject light received by the sensor into a live video in real time.   2. The sensor switching means for switching a sensor for receiving subject light, wherein the sensor is switched to the first sensor in a mirror-up state and the second sensor in a mirror-down state. The imaging device described.   The imaging apparatus according to claim 1, further comprising a temperature detection unit configured to detect a temperature of the first sensor, wherein the first sensor and the second sensor are switched in accordance with the detected temperature information.   The imaging apparatus according to claim 1, wherein the first and second sensors are switched according to a user instruction.   The imaging apparatus according to claim 1, wherein a continuous display time of a live video is determined and the first and second sensors are switched.   The live image developing means includes a normal image quality developing means for obtaining a final moving image and a simple developing means having lower power than the high image quality developing means, and the live image obtained by the second sensor is the simplified image. The image pickup apparatus according to claim 1, wherein a developing unit is used.   Temperature detection means for detecting the temperature of the first sensor, and according to the detected temperature information, the image quality of the live image is the normal image quality developed by the normal image quality development means or the first sensor. 9. The image pickup apparatus according to claim 8, wherein the second sensor switches between simple image quality developed by the simple image quality developing means.   In accordance with an instruction from the user, the image quality of the live video is either normal image quality obtained by developing the first sensor by the normal image quality developing means or simple image quality obtained by developing the second sensor by the simple image quality developing means. The image pickup apparatus according to claim 8, wherein the image pickup device is switched.   The continuous display time of the live video is determined, and the image quality of the live video is the normal image quality obtained by developing the first sensor by the normal image quality developing means or the simple image quality obtained by developing the second sensor by the simple image quality developing means. The imaging apparatus according to claim 8, wherein one of the two is switched.