JP2009302658A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus in which equipment operates in accordance with heat generation of a battery and appropriate continuous operation is performed in accordance with a use environment. <P>SOLUTION: A system control circuit 1 acquires internal temperature of a device body and temperature of a battery fitted to the device body. Also, the system control circuit 1 compares the acquired internal temperature and battery temperature of the device body, to increase the intervals of continuous photography sequences when the battery temperature is higher than the internal temperature of the device body by a prescribed value or more. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging apparatus such as an electronic camera (digital camera), and more particularly to an imaging apparatus that performs an appropriate operation and display with respect to the temperature of a battery used, that is, performs power suppression control.

  Recent electronic cameras are equipped with electrical components such as an image sensor and a liquid crystal monitor. When trying to obtain high-definition images during and after shooting, the electrical components are consumed depending on the processing capacity. Electricity to be used is increasing. In addition, in the control of the mechanism part, the improvement in processing speed in continuous shooting is a factor that increases power consumption.

  In general, the power source of the camera is a battery. However, when a high-definition image is continuously taken, the battery itself generates heat due to a continuous discharge current. If the battery discharge is continued while the temperature of the battery is raised, the cells inside the battery become abnormal, the deterioration progresses faster, and the mechanism part inside the battery is affected, resulting in a dangerous state.

  Therefore, as a countermeasure against abnormal heat generation on the battery side, a technique has been proposed in which the temperature inside the battery is monitored and control is performed so as to stop discharging when the battery reaches a specific temperature.

As a measure against battery heat generation on the device side, a data recording apparatus that performs load suppression control when the battery temperature reaches a predetermined threshold has been proposed (Patent Document 1).
JP-A-11-109439

  As described above, when an abnormality such as battery heat generation is detected, blocking the discharge on the battery side is effective for safe use of the battery.

  However, there is a problem that the device being used cannot perform appropriate processing due to sudden power interruption. On the device side, it is desirable that the power supply can be predicted to be cut off or controlled.

  Further, the technique described in Patent Document 1 is effective as a measure against heat generation of the battery on the device side because load suppression control is performed with a predetermined threshold.

  However, this is a single threshold determination based only on battery temperature information, and does not correspond to continuous operation.

  An object of the present invention is to provide an imaging apparatus that enables device operation corresponding to heat generation of a battery and can perform appropriate continuous operation according to the use environment.

  In order to achieve the above object, an imaging apparatus according to the present invention includes a first acquisition unit that acquires an internal temperature of an apparatus main body in an imaging apparatus that executes a continuous shooting sequence at predetermined time intervals, and the apparatus main body. The second acquisition means for acquiring the temperature of the battery attached to the battery, the internal temperature of the apparatus main body acquired by the first acquisition means, and the battery temperature acquired by the second acquisition means are compared. And control means for controlling the time interval between successive imaging sequences to be longer when the battery temperature is higher than a predetermined value with respect to the internal temperature of the apparatus main body.

  An imaging apparatus according to the present invention acquires, in an imaging apparatus that performs live view display at a predetermined frame rate, a first acquisition unit that acquires a temperature inside the apparatus main body, and a temperature of a battery that is attached to the apparatus main body. Compare the internal temperature of the apparatus main body acquired by the second acquisition means and the first acquisition means with the battery temperature acquired by the second acquisition means, and compare the internal temperature of the apparatus main body Control means for controlling the frame rate of the live view display to be lowered when the battery temperature is higher than a predetermined value.

  According to the imaging apparatus of the present invention, it is possible to perform device operation corresponding to the heat generation of the battery and perform appropriate continuous operation according to the use environment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block configuration diagram of a digital camera as an imaging apparatus according to an embodiment of the present invention.

  In FIG. 1, a camera body (apparatus body) 100 is in the form of a digital single-lens reflex camera, and a replaceable photographing lens 9 having an aperture function can be attached.

  A system control circuit 1 that controls the entire camera body 100 is a microcomputer having a ROM, a RAM, an A / D converter, a D / A converter, and a clock function. The internal program of the system control circuit 1 processes and controls the temperature monitoring of the battery (battery unit) 3 according to the present invention and the execution of each operation mode.

  The power supply control unit 2 includes a DC-DC converter, controls the DC-DC converter based on an instruction from the system control circuit 1, and supplies a necessary voltage to each necessary unit.

  The power supply terminal of the battery 3 is supplied to the power supply control unit 2, and immediately when a problem occurs in the power supply of the camera, the power supply control unit 2 is controlled to turn off the power supply to the camera.

  The battery 3 attached to the camera body 100 has a microcomputer mounted therein and can communicate with the camera body 100.

  The communication contents are battery information such as battery capacity, battery voltage, discharge current, battery temperature, battery deterioration information, and the like, and the battery information is transmitted to the camera body 100 and the battery information data is recorded in the memory. The temperature information of the battery is detected by the temperature detector 48 inside the battery 3.

  In the present embodiment, the battery 3 is illustrated as a communicable battery 3, but even a non-communicable battery that does not have a microcomputer is provided with a temperature measuring element such as a thermistor in the battery, and the information is directly displayed. The camera may recognize it.

  Connectors 4 and 5 serving as connecting portions between the battery 3 to be attached and the camera body 100 connect the power line and the communication line of the battery 3. Communication line. It is directly connected to the system control circuit 1 and also determines whether the battery is installed.

  The distance measurement control unit 6 controls focusing of the photographing lens 9. The distance measurement control unit 6 includes a distance measurement sensor, performs distance measurement selected from a plurality of distance measurement points, and takes a photographing lens in accordance with the aperture value (Av value) calculated by the system control circuit 1. 9 is controlled via the lens connection terminals 7 and 8 to open and close the aperture.

  The exposure control unit 10 that controls the shutter 11 includes a photometric sensor, and opens and closes the front curtain 12 and the rear curtain 13 of the shutter 11 according to the shutter time (Tv value) calculated by the system control circuit 1. Control.

  For example, the image sensor 20 such as a CCD converts an optical image into an electrical signal. The A / D converter 21 converts the analog signal output of the image sensor 20 into a digital signal.

  The timing generation unit 22 supplies a clock signal and a control signal to the image sensor 20, A / D converter 21, and D / A converter 24, and is controlled by the memory control unit 23 and the system control circuit 1.

  The image processing unit 25 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D converter 21 or the data from the memory control unit 23.

  The display image data written in the image display memory 26 is displayed on the information display unit 27 including a TFT color LCD or the like via the D / A converter 24.

  The information display unit 27 is installed on the back side of the camera, and displays various information notifications through image confirmation after shooting and communication with the system control circuit 1.

  The display during the image preview according to the present invention can be confirmed by the information display unit 27 serving as a monitor.

  The image data memory 28 is used to store a captured still image and encoded encoded information of shooting information, and has a sufficient storage capacity to store a predetermined number of still images.

  The image file generation unit 29 compresses and decompresses the image data into a file. The image file generation unit 29 reads an image stored in the image data memory 28, performs compression processing or decompression processing, and writes the processed data to the external memory 30 via the connectors 31 and 32 of the memory connection terminal.

  The external memory 30 is, for example, a card-type removable memory that is configured using a PCMCIA card, a flash memory card, or the like that conforms to a standard, and serves as a storage location for captured images.

  The shutter switch 40 includes a shutter switch SW1 (41) that activates the start of shooting and a shutter switch SW2 (42) that instructs the start of a series of shooting processes.

  The operation switch 43 is installed on the exterior of the camera, and includes a switch for determining various shooting conditions, a switch for editing and viewing a shot image, and the like. The mode dial 43 selects various shooting modes of the camera.

  The photographing information display unit 45 displays the operation state of the camera with characters, icons, etc. according to the execution of the program in the system control circuit 1 and is installed at a position near the operation switch 43 where it can be easily seen.

  The nonvolatile memory 46 that continues to be stored even when power supply to the EEPROM or the like is cut off stores settings such as shooting conditions.

  A temperature monitoring unit (monitoring means) 47 in the camera is configured by an element that electrically converts the measured temperature, for example, a thermistor, and sends temperature information to the system control circuit 1. Has function. The temperature monitoring unit 47 is provided on the condition that it is installed at a location where the temperature change in the camera is small and is not affected by the temperature due to the power consumption of the camera.

  The temperature detector 48 in the battery 3 is composed of an element that electrically converts temperature information, such as a thermistor, and serves as a data source for sending temperature information to the system control circuit 1. The temperature detection unit 48 is installed near the cell inside the battery 3 and is provided with the condition that temperature information that can grasp a change in the cell temperature due to the discharge of the battery 3 is obtained.

  Next, the relationship between general camera operation and battery temperature will be described with reference to FIG.

  FIG. 2 is a graph showing the relationship between the change in the temperature of the camera and the change in the temperature of the battery shown in comparison with the present invention, with the vertical axis representing temperature and the horizontal axis representing elapsed time.

  In the figure, the time until time A is when the amount of power consumed by the camera is small, and there is not much difference between the battery temperature and the internal temperature of the camera body, and both indicate a constant temperature Tc. This constant temperature Tc is a temperature approximate to the internal temperature of the camera body.

  When the camera is continuously operated starting from time A, the battery temperature rapidly increases in proportion to the elapsed time of power consumption as indicated by characteristic 201 in the figure.

  When the battery temperature reaches a specified temperature Tmax (time B), the discharge is cut off by safety means inside the battery 3.

  On the other hand, the camera temperature does not change with respect to the power consumption, and maintains a constant temperature until time B as shown by the characteristic 203. When the discharge of the battery 3 is cut off, the camera operation is terminated, and the subsequent power consumption is eliminated.

  The battery 3 after time B gradually decreases in temperature as the characteristic 202 due to natural heat dissipation.

  The camera temperature after the time B becomes impossible to measure because the operation is finished, but when the camera is restarted, it shows a constant temperature (camera ambient temperature) as it is.

  Next, the relationship between the operation of the camera of the present invention and the battery temperature will be described with reference to FIG.

  FIG. 3 is a graph showing the relationship between the temperature change of the digital camera and the battery temperature change in FIG. 1, with the vertical axis representing temperature and the horizontal axis representing elapsed time.

  In the figure, the time until time A is when the amount of power consumed by the camera is small, and there is not much difference between the battery temperature and the internal temperature of the camera body, and both indicate a constant temperature Tc. This constant temperature Tc is a temperature approximate to the internal temperature of the camera body.

  When the camera is continuously operated starting from time A, the battery temperature rapidly rises in proportion to the elapsed time of power consumption as indicated by characteristic 301 in the figure.

  The camera detects the battery temperature and the internal temperature of the camera body, and when the battery temperature reaches a temperature higher than Td1, which is a specified temperature difference with respect to the internal temperature of the camera body (time B), power suppression control (A power suppression operation mode is executed). That is, the power suppression operation mode is executed when the battery temperature is higher than a predetermined value with respect to the internal temperature of the camera body.

  During the power suppression operation mode, the battery temperature rises more slowly than during normal power operation, and camera operation control is performed according to predetermined battery temperature detection points (Td2, Td3,..., Tdn).

  Details and specific examples of the power suppression operation mode will be described later.

  Even if the power suppression operation mode is continued, when the battery temperature reaches the specified temperature Tmax (C time), the discharge is cut off by the safety means inside the battery.

  As a plurality of temperature detection points are provided during the power suppression operation mode, the operation until the battery 3 stops discharging can be controlled more finely. Furthermore, since the camera controls the temperature rise of the battery 3, it is possible to prevent a sudden power shutdown.

  Next, the basic operation of the power suppression operation mode will be described using the flowchart of FIG.

  FIG. 4 is a flowchart showing a procedure of processing in the power suppression operation mode executed by the digital camera of FIG.

  This flow is a process performed while the digital camera is continuously operating, and is executed by the system control circuit 1 at predetermined intervals after time A in FIG.

  In FIG. 4, first, in step S <b> 401, the system control circuit 1 performs battery communication (communication with the battery 3) and acquires temperature information of the battery 3. Here, temporarily obtained battery temperature data (second temperature information) is defined as Tbt, and this Tbt is stored in the system control circuit 1.

  Step S <b> 401 functions as a second acquisition unit that acquires the second temperature information of the battery 3.

  In step S402, the system control circuit 1 compares the acquired battery temperature data Tbt with a preset specified temperature Td1, and if the battery temperature data Tbt is less than the specified temperature Td1, the normal control in step S403 is performed. Continue operation.

  This is a temperature determination process between time A and time B in FIG. 3, and is a process that is executed to continue normal operation until the battery temperature reaches a specified temperature.

  In step S402, when the battery temperature data Tbt becomes equal to or higher than the specified temperature Td1, the process proceeds to step S404, and the system control circuit 1 performs the process of the power suppression operation mode.

  In step S405, the system control circuit 1 displays a notice on the information display unit 27 or the photographing information display unit 45 that the power suppression operation is being performed.

  The notification display in this case is for the purpose of easily displaying to the user that the suppression operation different from the normal operation is being performed. For example, the notification display of the battery 3 and the thermometer may be displayed at the same time.

  Step S405 functions as a display unit that performs a specific display during the power suppression control.

  In step S <b> 406, the system control circuit 1 acquires current camera temperature information from the temperature monitoring unit 47. Here, it is assumed that the acquired camera temperature data (first temperature information) is Tc, and this Tc is stored in the system control circuit 1.

  Step S406 functions as a first acquisition unit that acquires the first temperature information of the monitoring unit.

  In step S407, the system control circuit 1 calculates the difference between the acquired camera temperature data Tc and the battery temperature data Tbt, and sets the obtained result as Tdx. The result Tdx corresponds to Td2, Td3,..., Tdn in FIG.

  In step S408, the system control circuit 1 collates a data table preset in the system control circuit 1 with the calculation result Tdx, and selects an operation control that provides predetermined power suppression.

  In step S409, the system control circuit 1 executes each routine operation so as to perform the predetermined operation selected in step S408. Then, this process ends.

  Step S409 functions as a control unit that performs a plurality of power suppression controls based on the first temperature information and the second temperature information.

  As described above, the system control circuit 1 controls the operation that suppresses the power step by step in accordance with the temperature rise of the battery 3. Further, the system control circuit 1 continuously measures the battery temperature at a predetermined interval and reflects the result on the suppression operation, so that the suppression operation in accordance with the rise or fall of the battery temperature is possible.

  Next, a specific example of the camera operation of the present embodiment will be described with reference to FIGS.

  FIG. 5 is a diagram illustrating an example of the power suppression operation (operation in the power suppression mode) at predetermined intervals, which is executed by the digital camera of FIG.

  An example of the camera operation is a sequence interval in continuous shooting. In the present embodiment, control is performed to vary the time interval of the sequence in continuous shooting.

  In FIG. 5, in normal operation, continuous shooting is performed at a predetermined interval, and this camera operates in a drive sequence that provides the maximum number of continuous shots.

  In the figure, Pt includes an image processing time until the next sequence, a standby time of the camera, and the like, and does not include an actual imaging process. Therefore, the period of Pt is a time with less power consumption in the imaging sequence.

  In the power suppression operation, as described with reference to FIGS. 3 and 4, Tdn is set as the battery temperature increases.

  When the battery temperature is Td1, a predetermined time is obtained by extending the time Pt of the imaging sequence (Pt × 2).

  When the battery temperature is Td2, the time of Pt is a predetermined time extended from Td1 (Pt × 3).

  When the battery temperature is Td3, the Pt time is a predetermined time longer than Td2 (Pt × 4).

  When the battery temperature returns to Td2, the corresponding predetermined time is reached (Pt × 2).

  Similarly, when the battery temperature is Tdn, the Pt time is a predetermined related time (Pt × n).

  As described above, continuous power consumption can be suppressed and heat generation of the battery 3 can be suppressed by adjusting the off-period time during operation performed at predetermined intervals in accordance with the temperature rise of the battery 3. .

  Although continuous shooting has been described with reference to FIG. 5, the present invention is not limited to this, and can be handled as adjustment of the off period in sequence driving performed continuously for the purpose of power consumption.

  FIG. 6 is a diagram illustrating an example of the power suppression operation (operation in the power suppression mode) in the continuous operation executed by the digital camera of FIG. 1.

  As an example of the camera operation, there is a live view display operation for displaying a through image on the rear monitor (information display unit 27). In the present embodiment, control is performed to vary the frame rate in the live view display operation, that is, the number of frames at the time of image reading.

  In FIG. 6, in normal operation, live view display is continuously performed on the rear monitor, and the camera operates in an imaging readout sequence that provides the maximum number of frames (frame rate) of this camera (30 frames per second). .

  The imaging readout interval is proportional to the power consumption, and the power consumption may be reduced if the number of frames (frame rate) is reduced. Therefore, when power suppression is performed, adjustment is performed within a range where the live view image can be recognized.

  In the power suppression operation, as described with reference to FIGS. 3 and 4, Tdn is set as the battery temperature increases.

  When the battery temperature is Td1, the number of read frames (frame rate) for live view display is 26f (26f / sec).

  When the battery temperature is Td2, the number of read frames (frame rate) for live view display is 22f (22f / sec).

  When the battery temperature is Td3, the number of read frames (frame rate) for live view display is 18f (18f / sec).

  When the battery temperature returns to Td2, the corresponding predetermined number of frames (frame rate) is obtained (22f / sec).

  Similarly, when the battery temperature is Tdn, the related readout frame number (frame rate) is obtained (14 f / sec).

  As described above, continuous power consumption can be suppressed and heat generation of the battery 3 can be suppressed by setting the power suppression corresponding to the operation performed continuously in accordance with the temperature rise of the battery 3. can do.

1 is a block configuration diagram of a digital camera as an imaging apparatus according to an embodiment of the present invention. It is a graph which shows the relationship between the temperature change of a camera and the temperature change of a battery shown on the comparison with this invention. 2 is a graph showing a relationship between a temperature change of the digital camera and a battery temperature change in FIG. 1. It is a flowchart which shows the procedure of the process at the time of the electric power suppression operation mode performed by the digital camera of FIG. It is a figure which shows an example of the power suppression operation | movement (operation | movement at the time of power suppression mode) in the predetermined space | interval performed with the digital camera of FIG. It is a figure which shows an example of the power suppression operation | movement (operation | movement at the time of power suppression mode) in the continuous operation | movement performed with the digital camera of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 System control circuit 3 Battery 27 Information display part 47 Temperature monitoring part

Claims (2)

In an imaging apparatus that executes a continuous shooting sequence at predetermined time intervals,
First acquisition means for acquiring the temperature inside the apparatus body;
Second acquisition means for acquiring the temperature of a battery mounted on the apparatus body;
The internal temperature of the apparatus main body acquired by the first acquisition means is compared with the battery temperature acquired by the second acquisition means, and the battery temperature is equal to or higher than a predetermined value with respect to the internal temperature of the apparatus main body. Control means for controlling to increase the time interval between successive shooting sequences when the temperature is high;
An imaging apparatus comprising: In an imaging device that performs live view display at a predetermined frame rate,
First acquisition means for acquiring the temperature inside the apparatus body;
Second acquisition means for acquiring the temperature of a battery mounted on the apparatus body;
The internal temperature of the apparatus main body acquired by the first acquisition means is compared with the battery temperature acquired by the second acquisition means, and the battery temperature is equal to or higher than a predetermined value with respect to the internal temperature of the apparatus main body. Control means for controlling the frame rate of the live view display to be low when the temperature is high;
An imaging apparatus comprising:

Images