JP4171709B2 - Digital camera - Google Patents

Description

  The present invention relates to a digital camera driven by a dry battery or a rechargeable battery, and more particularly to a digital camera that can be driven for a long time.

  A conventional digital camera, for example, as described in Patent Document 1 below, prohibits the display of a liquid crystal display (LCD) attached to the back of the camera or the like when the voltage of the power battery drops to a predetermined voltage. In addition, the flash emission is prohibited and the auto focus is prohibited, so that the battery is not consumed and the digital camera can shoot as long as possible.

JP 2000-253303 A

  When the power supply battery of the digital camera is exhausted, the power consumption is suppressed by prohibiting some functions mounted on the digital camera, and the battery life can be extended. However, there is also a problem that the usability of the camera is lowered by prohibiting a part of the original functions of the camera.

  For example, even if the user thinks that the flash is naturally emitted and the shutter is released, if an image that does not emit the flash is captured, the captured image with poor image quality is discarded, and unnecessary shooting is performed. Become. Further, even if the user thinks that an autofocus function works and can capture a focused image, the image data is also wasted if a defocused image is captured even if the shutter is released.

  An object of the present invention is to provide a digital camera capable of extending the battery life without stopping the main functions of the camera when the battery is exhausted and capable of capturing a good image to the end.

In the digital camera of the present invention, when the output voltage value of the power supply battery is equal to or higher than a specified value, the camera function is operated at the required speed by supplying the required power from the power supply battery to the drive control unit that operates the camera function In the digital camera, when the output voltage of the power supply battery is less than the specified value, the drive control unit is controlled to control the camera function at a speed lower than the required speed , the camera function, A first processing function for performing from imaging of a subject by a solid-state imaging device to reading of captured image data from the solid-state imaging device; and a second processing function for performing image processing on the captured image data read from the solid-state imaging device; The drive control unit is configured such that when the output voltage value of the power supply battery falls below the specified value, the output voltage value is equal to or greater than the specified value. By reducing the overlap amount of parallelism with acceptable first processing function is a second processing function and performs the processing speed of the camera function at a low speed.

With this configuration, the user can use a camera function that functions at a low speed even when the battery is exhausted, and can provide a digital camera that can take a long time while effectively using the remaining battery power. In addition, although the time until the apparent processing speed is reduced and the next shutter release is permitted becomes longer, it is possible to shoot for a long time while suppressing battery consumption.

The camera function of the digital camera of the present invention is a function of charging a flash capacitor required for flash emission, and when the output voltage value of the power supply battery is lower than the specified value, the drive control unit moves the flash capacitor to the flash capacitor. Charging is performed at a low current and low speed compared to when the output voltage value of the power battery is equal to or greater than the specified value.

  With this configuration, it is possible to perform shooting with flash emission even when the battery is exhausted.

  The drive controller of the digital camera of the present invention is provided with a plurality of charge current values that are set to be smaller as the output voltage value becomes smaller as the charge current value of the flash capacitor that performs charging at the low current and low speed in advance. It is characterized by being.

  With this configuration, fine charge control can be performed, and the remaining battery level can be used more effectively.

  In the digital camera of the present invention, the overlap amount is set to “0”, and when the second processing function is being performed, pressing of a shutter release button that instructs the start of execution of the first processing function is prohibited. And

  With this configuration, when the battery is consumed, only so-called single shooting is allowed, but shooting itself is possible.

  The camera function of the digital camera of the present invention is an autofocus function for obtaining a focus position up to a subject and driving the lens system to the focus position by a motor, and the drive control unit outputs an output voltage value of the power battery. Is less than the specified value, the motor drive is performed at a lower speed than when the output voltage value is greater than or equal to the specified value.

  With this configuration, the time until the lens is focused is longer than when the battery is not consumed, but it is possible to capture a good image in focus.

  The camera function of the digital camera of the present invention is a function of writing captured image data read from the solid-state image sensor and subjected to image processing to an external memory, and the drive control unit is configured such that the output voltage value of the power battery is the specified value. When the output voltage value is lower than the specified value, the data rate for accessing the external memory is made lower than that when the output voltage value is equal to or higher than the specified value.

  With this configuration, battery consumption required for data recording can be suppressed, and the digital camera can be used for a long time.

The digital camera of the present invention is driven by a power supply battery, and at least a flash light emission function, an autofocus function, a display function of a display unit instead of a finder, and imaging of subject from a solid-state imaging device, from the solid-state imaging device A function for performing parallel processing on the first processing for reading up to and the second processing for performing image processing on the captured image data read from the solid-state imaging device, and the captured image data subjected to the image processing in an external memory In a digital camera having a recording function, when the output voltage value of the power battery falls below a specified value , the flash emission function, the autofocus function, and the display function are all maintained in an operable state. Compared to when the output voltage value of the power battery is equal to or higher than the specified value, the flash capacitor charging operation and Reducing the display brightness of the display portion performs an autofocus operation with a small current low speed, and is the output voltage value of the power supply battery is more than the prescribed value and sets "0" to overlap the parallel processing compared to, characterized in that it comprises control means you data rate for accessing the external memory at a low speed when.

With this configuration, the camera function is reduced when the battery is consumed, but the main camera function can be used, so that the user can take a good image for a long time. Further, it is possible to further reduce power consumption when the battery is consumed.

  The digital camera of the present invention further includes a speaker and a sound control unit that controls sound output from the speaker, and the control means outputs the power from the speaker when the output voltage value of the power battery falls below the specified value. The volume of the audio output is controlled to be lower than that when the output voltage value of the power battery is equal to or higher than the specified value.

  With this configuration, it is possible to reduce power consumption required for audio output.

  The digital camera of the present invention is a digital camera equipped with a speaker for outputting sound and driven by a power supply battery, wherein the power supply is compared with the sound output volume when the output voltage value of the power supply battery is equal to or higher than a specified value. Control means is provided for controlling the volume to a low volume when the output voltage of the battery falls below the specified value.

  With this configuration, power consumption required for audio output can be reduced, and battery life can be extended.

  According to the present invention, even if the battery is depleted, the camera is operable at low speed, low speed control, low luminance display, and low volume output, but can operate, so the digital camera is used until the battery is exhausted. It becomes possible.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of a digital still camera according to an embodiment of the present invention. The digital still camera shown in FIG. 1 includes a photographic lens 10, a solid-state image sensor 11, a diaphragm 12 provided between them, an infrared cut filter 13, and an optical low-pass filter 14.

  The CPU 15 that controls the entire digital still camera controls the light emitting unit 16 for flash, and also controls the lens driving unit 17 to automatically adjust the position of the photographing lens 10 to the focus position, via the aperture driving unit 18. The aperture amount of the diaphragm 12 is controlled so that the exposure amount becomes an appropriate exposure amount.

  Further, the CPU 15 drives the solid-state image sensor 11 via the image sensor driving unit 19 and outputs a subject image captured through the photographing lens 10 as a color signal. Further, the CPU 15 recognizes a user instruction by taking in an input signal from various switches 20 attached to the camera housing via the switch control unit 21 and performs various controls according to the user instruction.

  The electric control system of the digital still camera includes an analog signal processing unit 22 connected to the output of the solid-state imaging device 11 and A / D conversion for converting RGB color signals output from the analog signal processing unit 22 into digital signals. The circuit 23 is provided and these are controlled by the CPU 15.

  Further, the electric control system of the digital still camera includes a memory control unit 25 connected to the main memory 24, a digital signal processing unit 26 that performs white balance correction processing, gamma correction processing, and other image processing, and a captured image. A compression / decompression processing unit 27 that compresses the image into a JPEG image or decompresses the compressed image, an integration unit 28 that integrates photometric data and passes the integrated value to the digital signal processing unit 26, and a detachable semiconductor memory or the like. An external memory control unit 30 to which the recording card 29 is connected, a display control unit 32 to which a liquid crystal display unit 31 mounted on the back of the camera or the like is connected, and a voice that is connected to the speaker 33 and outputs voice guidance or the like from the speaker 33 And a control unit 34, which are connected to each other by a control bus 35 and a data bus 36, and controlled by a command from the CPU 15. It is.

  The digital still camera of the present embodiment further includes a voltage detection unit 40 that detects a voltage connected to the output of the power supply battery 39, and boosts the battery output to a required voltage value connected to the output of the power supply battery 39. And a charge control unit 34 for controlling the charging current of the flash capacitor 42 that outputs accumulated charge to the light emitting unit 16, which are connected to the control bus 35, and in response to a command from the CPU 15. Work on the basis.

  FIG. 2 is a flowchart showing a processing procedure executed by the CPU 15 having the above-described configuration. When the power switch is turned on, the CPU 15 initializes the digital still camera (step S1), and then sets the operation state of the digital still camera to the normal operation state (step S2).

  The normal operation state is a state in which the digital still camera can be driven at a high current and a high speed and can be operated at a high quality. For example, the illumination brightness of the liquid crystal display unit 31 is increased so that the display unit 31 is easy to see, the charging current of the flash capacitor 42 is set to be maximum so that high-speed charging is possible, and the shooting sequence can be taken quickly. To make it easier for the user to hear by increasing the sound from the speaker 33, to set the data access speed for reading and writing the captured image data to the recording card 29, and to operate the autofocus function at high speed. Set to.

  In the next step S3, the output voltage value of the power supply battery 39 is read from the voltage detector 40, and it is determined whether or not this voltage value is equal to or greater than a specified value. That is, it is determined whether or not the battery is exhausted. If the battery is not depleted, the process proceeds to step S4 to determine whether or not the user has performed a switch operation. When the switch operation is not performed (determination result is NO), the process returns to step S3, and it is always checked whether or not the output voltage value of the power supply battery 39 is equal to or higher than a specified value.

  When a switch operation is input, the process proceeds from step S4 to step S5, a process corresponding to the switch operation is executed, and the process returns to step S3 again. In this case, since the digital still camera is set in the normal operation state in step S2, the process in step S5 corresponding to the switch operation is performed in the normal operation.

  That is, if the switch operation is to select a shooting mode, the flash capacitor 42 is charged with a large current to perform high-speed charging, and if the shutter release button is half-pressed, the autofocus function is operated at high speed to focus the subject. And the lens driving unit 17 is operated at high speed.

  When the shutter release button is continuously pressed, the imaging data of the current shooting is read from the solid-state imaging device 11 and output to the digital signal processing unit 26, and then in parallel with the image processing performed by the digital signal processing unit 26. Then, the process of reading the imaging data of the next shooting from the solid-state imaging device 11 is performed in parallel. That is, each process performed by the digital still camera is processed in parallel, and the parallel overlap is increased to speed up each process. When each processing is performed in parallel, the power consumption increases, but there is no problem because the remaining battery level is sufficient. Further, when image data compressed after image processing is written to the recording card 29, the card is accessed at a high speed, and writing is performed at a high data rate.

  If the switch operation determined in step S4 is a switch operation for selecting an image reproduction mode or a menu operation mode, the illumination brightness of the liquid crystal display unit 31 is increased to make the screen easy to see, and from the recording card 29 at a high data rate. The target image data is read out and displayed on the liquid crystal display unit 31 or a menu operation screen is displayed. Further, the volume of voice output such as voice guidance is increased to make it easier to hear.

  As a result of the determination in step S3, if it is determined that the battery voltage has become lower than the specified voltage, the process proceeds from step S3 to step S6, and the setting of the normal operation state set in step S2 is changed to the energy saving operation state. Then, step S4 is entered.

  The energy saving operation state refers to a state where the digital still camera is driven at a low current and a low quality at a low current. For example, the illumination brightness of the liquid crystal display unit 31 is set low, the charging current of the flash capacitor 42 is set to a small current, and the overlap of the parallel processing in the photographing sequence is set small. Preferably, the overlap is eliminated and each process is performed independently. Also, the audio output from the speaker 33 is set small, the data access speed for reading / writing the captured image data to the recording card 29 is set low, the data transfer interval is lengthened, and the autofocus function is set to operate at low speed. To do.

  Thereby, the process in step S5 performed by the digital still camera set to the energy saving operation state is performed by the energy saving operation, and power consumption is suppressed. That is, the display brightness of the liquid crystal display unit 31 is lowered to such an extent that the display contents can be visually recognized even when the liquid crystal display unit 31 is used as a viewfinder, and voice guidance and the like are performed at a low volume. Note that since voice guidance or the like is not a main function of the camera, this function may be stopped.

  Further, even if the user continuously presses the shutter release button, the current imaging data is read from the solid-state imaging device 11, processed by the digital signal processing unit 26, and after data compression, the data is compressed at a low rate to the recording card. The next shutter is not released unless it is recorded. That is, only a single shot is accepted. Furthermore, the autofocus function also reduces, for example, the rate at which the image data for calculating the in-focus position is captured from the solid-state imaging device 11 from the normal operation state, and the motor drive for moving the lens 10 to the in-focus position is a small current. To reduce power consumption.

  As described above, in the digital camera according to the present embodiment, all the original main functions of the camera mounted on the digital camera can be used even when the battery is exhausted, so the user can use the digital camera with peace of mind. Shooting is possible, battery consumption due to unnecessary shooting can be avoided, and battery life can be maintained for a long time.

  In addition, the digital camera according to the present embodiment has an advantage that when the battery is exhausted, the processing speed of the main functions of the camera is reduced to reduce power consumption, so that the battery capacity can be used up. . Even if the battery capacity is still sufficient, if a large current is temporarily used, a large voltage drop (decrease) occurs, temporarily lowering the minimum operating voltage of the digital camera, and the digital camera becomes inoperable. End up. However, in the digital camera according to the present embodiment, all of the main processing is performed by low current low speed driving and low quality driving so that a large voltage drop does not occur. Therefore, the time required to ensure the minimum operating voltage required for camera operation is long. Battery capacity can be used up.

  In the above-described embodiment, the energy saving operation is set to one type, but a plurality of energy saving operation settings may be provided. For example, as the charging current value of the flash capacitor, four current values are set as follows: normal time A1> energy saving A2> energy saving A3> energy saving A4, and depending on the detected voltage value of the power battery A1, A2, It is also possible to use a current value of any of A3 and A4. Similarly, the display brightness of the display unit 31, the degree of overlap in parallel processing, the playback volume, the card access data rate, and the autofocus processing speed are selected from a plurality of values according to the remaining battery voltage during the energy saving operation. It may be configured.

  The present invention is useful when applied to a battery-powered digital camera, because it extends the battery life and uses up the battery capacity.

It is a block block diagram of the digital still camera which concerns on one Embodiment of this invention. It is a flowchart which shows the process sequence which CPU shown in FIG. 1 performs.

Explanation of symbols

10 Lens 11 Solid-state imaging device 15 CPU
16 Flash light emitting unit 17 Lens driving unit 18 Aperture driving unit 19 Image sensor driving unit 26 Digital signal processing unit 29 Recording card 30 External memory control unit 31 Liquid crystal display unit 33 Speaker 34 Audio control unit 39 Power supply battery 40 Voltage detection unit 42 Flash capacitor 43 Charge control unit

Claims (9)

When the output voltage value of the power supply battery is equal to or greater than a specified value, in the digital camera that supplies the required power from the power supply battery to the drive control unit that operates the camera function and functions the camera function at the required speed, the power supply battery the output voltage is provided with control means for the functional than the required speed at a low speed the camera function by controlling the drive control unit when below the specified value, the camera function, image of an object by the solid-state imaging device And a second processing function for image processing the captured image data read from the solid-state image sensor, and the drive control unit. The first process that is permitted when the output voltage value is equal to or greater than the specified value when the output voltage value of the power supply battery falls below the specified value. Digital camera and performing the processing speed of the camera function at low speed to reduce the overlap amount of parallelism between the Noh second processing function. The camera function includes a charging function of a flash capacitor required for flash emission, and when the output voltage value of the power supply battery is lower than the specified value, the drive control unit sets the flash capacitor to the output voltage value of the power supply battery. 2. The digital camera according to claim 1, wherein charging is performed at a low current and a low speed as compared with a case where the current value is equal to or greater than the specified value. The drive control unit is provided with a plurality of charging current values that are set in advance as the output voltage value decreases as the charging current value of the flash capacitor that performs charging at the low current and low speed. The digital camera according to claim 2. The overlap amount is set to "0", the second processing function when is being performed and inhibits depression of the shutter release button for instructing start of execution of the first processing function claims 1 to Item 4. The digital camera according to any one of Items 3 . The camera function includes an autofocus function that obtains a focus position up to a subject and motor-drives the lens system to the focus position, and the drive control unit is configured such that the output voltage value of the power battery falls below the specified value. If the digital camera according to any one of claims 1 to 4 wherein the output voltage value and performing the motor drive compared to when more than the predetermined value at low speeds. The camera function includes a function of writing captured image data read from the solid-state imaging device and subjected to image processing to an external memory, and the drive control unit is configured to output the power battery when the output voltage value of the power battery falls below the specified value. the digital camera according to any one of claims 1 to 5, characterized in that the data rate which the output voltage value to access the external memory as compared to when more than the specified value at a low speed. A first battery that is driven by a power supply battery and performs at least a flash light emitting function, an autofocus function, a display function of a display unit instead of a finder, and a process from imaging of a subject by a solid-state imaging device to reading of captured image data from the solid-state imaging device. Digital having a function of performing parallel processing on a second process for performing image processing on the captured image data read from the solid-state image sensor and a function for recording the captured image data subjected to the image processing in an external memory in the camera, when said output voltage value of the power supply battery falls below a specified value, the flash light emitting function and the auto-focus function and the display function and the output voltage value of the power supply battery while maintaining all operable Compared to when the value exceeds the specified value, the flash capacitor charging and autofocus operations are reduced. Flow reduces the display brightness of the display unit performs at low speed, and, the output voltage value of the power supply battery and sets "0" to overlap the parallel processing compared to when more than the specified value digital camera, characterized in that it comprises control means you data rate for accessing the external memory at a low speed. A speaker and a sound control unit that controls sound output from the speaker, and the control means controls the sound output volume from the speaker when the output voltage value of the power supply battery falls below the specified value. The digital camera according to any one of claims 1 to 7 , wherein the volume is controlled to be lower than that when the output voltage value of the power battery is equal to or greater than the specified value. In a digital camera equipped with a speaker for performing audio output and driven by a power supply battery, the output voltage of the power supply battery is compared with the volume of the audio output when the output voltage value of the power supply battery is greater than or equal to a specified value. A digital camera comprising control means for controlling the volume to a low volume when the value falls below the value.

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