JP2003037768A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera that can realize reduction in waiting time for the user, and prolonging of the service life of a battery. SOLUTION: In the electronic camera where a plurality of modes for conducting different processings can be selected, a system clock frequency in the inside of the electronic camera is selected, in response to the selection of the mode. A plurality of the modes include an imaging mode, where an object is imaged to acquire image data and a non imaging mode for conducting other processing and a changeover means sets the clock frequency in the non imaging mode lower than the clock frequency in the imaging mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera that acquires image data of a subject with an image sensor.

[0002]

2. Description of the Related Art A general electronic camera is equipped with an image pickup device for obtaining image data and an image processing circuit for performing image processing on the image data. In recent years, the number of pixels of the image pickup device of this electronic camera has been rapidly increasing in response to a demand for image quality improvement by a user.

[0003]

However, since the increase in the number of pixels complicates image processing, the time required for image pickup (the time from the start of image pickup to the recording of image data).
It is necessary to devise so that it does not become long. This is because if the time required for image capturing becomes long, the waiting time by the user increases and there is a possibility that a photo opportunity will be missed.

However, even if the system clock frequency is simply increased in order to increase the processing speed of the image processing circuit, the power consumption is increased accordingly, which causes another problem that the battery life is shortened. Therefore, it is an object of the present invention to provide an electronic camera capable of realizing both a reduction in waiting time by a user and an extension of battery life.

[0005]

The "mode of the electronic camera" referred to in the present specification means the "state of the electronic camera". Therefore, the types of modes in the present invention are not limited to the types of modes described in the specifications of electronic cameras. The electronic camera according to claim 1, wherein the electronic camera is capable of switching to a plurality of modes in which different processes are executed, and a switching means for switching a system clock frequency inside the electronic camera according to the switching of the modes. It is characterized by having.

In this way, if the system clock frequency is switched according to the need, the efficiency of the internal processing of the electronic camera can be improved. The electronic camera according to claim 2,
The electronic camera according to claim 1, wherein the mode is
The switching unit includes an imaging mode for performing imaging and acquiring image data and a non-imaging mode for performing other processing, and the switching unit sets the clock frequency in the imaging mode higher than the clock frequency in the non-imaging mode. It is characterized by setting.

The electronic camera according to claim 3 is the electronic camera according to claim 2.
In the electronic camera described in [1], the determination of the image capturing condition is performed in the image capturing mode. According to a fourth aspect of the present invention, in the electronic camera according to the second aspect, the imaging condition is determined in the non-imaging mode. The electronic camera according to claim 5 is the electronic camera according to any one of claims 2 to 4, wherein the non-imaging mode is a reproduction mode for reproducing and displaying an image obtained by past imaging. And a non-imaging non-reproducing mode for performing other processing, wherein the switching means sets the clock frequency in the regenerating mode and the clock frequency in the non-imaging non-reproducing mode to different values. Is characterized by.

According to a sixth aspect of the present invention, there is provided an electronic camera including an operation member for an operator to perform an operation, wherein the system clock frequency inside the electronic camera is changed according to the operation of the operation member. It is characterized by having means. In this way, if the system clock frequency is switched according to the state of the electronic camera, the system clock frequency can be switched according to need, so that the efficiency of internal processing of the electronic camera can be improved.

An electronic camera according to a seventh aspect is the electronic camera according to the sixth aspect.
In the electronic camera described in the item (1), the operation member is a release button for causing the electronic camera to perform imaging, and the switching unit sets the clock frequency when the release button is operated to a non-operation of the release button. It is characterized in that it is set higher than the clock frequency at the time.

The electronic camera according to claim 8 is the electronic camera according to claim 7.
In the electronic camera described in (1), the operation member is a release button that causes the electronic camera to take an image at the time of full-press operation and causes the electronic camera to determine an imaging condition at the time of half-press operation, and the switching unit is the The clock frequency when the release button is fully pressed and half-pressed is set higher than the clock frequency when the release button is not operated.

An electronic camera according to a ninth aspect is the electronic camera according to the seventh aspect.
In the electronic camera described in (1), the operation member is a release button that causes the electronic camera to take an image at the time of full-press operation and causes the electronic camera to determine an imaging condition at the time of half-press operation, and the switching unit is the The clock frequency when the release button is fully pressed is set to be higher than the clock frequency when the release button is half-pressed and not operated.

An electronic camera according to a tenth aspect of the present invention is the electronic camera according to any one of the seventh to ninth aspects, wherein as the operation member, the operation of the image pickup by the release button is invalidated. A reproduction setting member for causing the electronic camera to perform reproduction display is further provided, and the switching means includes the clock frequency when the reproduction setting member is set, and the release button when the reproduction setting member is not set. The clock frequency when not operated is set to a value different from each other.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> A first embodiment of the present invention will be described with reference to FIGS. 1, 2, 3 and 4. FIG. 1 is a block diagram of the electronic camera of this embodiment.

The image data acquired inside the electronic camera 1 is recorded in the external storage device 26 or the like connected to the electronic camera 1 via the connector 25. The electronic camera 1 includes a lens 11, a lens driving unit 13, a CCD image pickup device 21, an analog signal processing circuit 22a, an A / D conversion circuit 22b, a memory 23, a compression / expansion circuit 24, a video circuit 27, a monitor 28, a connector 25, Release switch 3
0a, mode switch 30b, CPU 29, R
An OM 29a, a RAM 29b, a frequency dividing circuit 32, a clock generating circuit 31, etc. are provided.

Here, the memory 23, the video circuit 27,
Image processing block 2a including a compression / expansion circuit 24 and the like
Are configured as the same image processing IC 2. And
In this embodiment, the CPU 29 and the frequency dividing circuit 32 are also formed on the same image processing IC 2 as the image processing block 2a.

Then, the CPU 29 divides the system clock frequency in the image processing block 2a by the frequency dividing circuit 32.
Set via. The frequency dividing circuit 32 converts the frequency of the clock generated by the clock generating circuit 31 according to an instruction from the CPU 29, and supplies the frequency to the image processing block 2a. Here, the frequencies that can be set by the frequency dividing circuit 32 of this embodiment are at least two types, f1 and f2.

Incidentally, the CPU 29 sets the system clock frequency as described above and, in the same manner as the CPU in the conventional electronic camera, controls the sequence of each part in the electronic camera 1 according to the operation of the release switch 30a and the mode changeover switch 30b. To do. FIG. 2 shows the CP of this embodiment.
It is a figure explaining the relationship between the mode of the electronic camera 1 set by U29, and a system clock frequency.

As shown in FIG. 2, the modes set in the electronic camera 1 are roughly classified into an imaging mode and a reproduction mode, and the imaging mode further comprises two modes of an imaging preparation period and an imaging period. . The switching between the image capturing mode and the reproduction mode is performed by the user's operation of switching the mode switching switch 30b.

Further, in the image pickup mode, the transition between the image pickup preparation period and the image pickup period is performed by the user's release switch 3.
It is performed by the operation / non-operation of 0a. First, in the image pickup mode, in the electronic camera 1, the CCD image pickup device 21
Is a mode in which an image formed by the lens 11 is captured and converted into an electric signal. Further, in this image pickup mode, the signal output from the CCD image pickup device 21 is subjected to predetermined signal processing in the analog signal processing circuit 22a, then digitized in the A / D conversion circuit 22b, and then processed in the image processing block 2a. It is sequentially input to the memory 23.

Here, the processing performed on this signal in the image processing block 2a differs between the imaging preparation period and the imaging period. During the imaging preparation period, the signal is the video circuit 27.
Is converted into a video signal suitable for the monitor 28 and then displayed as a through image on the monitor 28. On the other hand, during the imaging period, the signal is compressed as image data for recording by the compression / expansion circuit 24 in a format (such as JPEG) suitable for the external storage device 26, and then written to the external storage device 26 via the connector 25. Be done.

It should be noted that here, the image pickup period is ended when the writing to the external storage device 26 is completed and the subsequent image pickup becomes possible. However, memory 2
When the capacity of 3 is sufficiently large, the end of the imaging period is
This is the time when the compressed file to be written to the external storage device 26 is completed (that is, the end of the imaging period is the time when the subsequent imaging becomes possible).

Of these, the image data acquired during the imaging preparation period (image data of a through image) and the image data for recording acquired during the imaging period have a larger amount of information. This is realized by switching the method of reading the signal from the CCD image pickup device 21. Therefore, between the image capturing preparation period and the image capturing period, the image processing block 2a performs more complicated processing in the latter case.

In the electronic camera 1 of the present embodiment, the image pickup condition is determined when the release switch 30a is half-pressed, and the image pickup when the release switch 30a is fully pressed is performed under the image pickup condition. The function to do is added. For example, an auto focus (A) that gives an instruction to the lens driving unit 13 to automatically focus the lens 11
In F), it is a function (AF lock) of determining the focus position of the lens 11 at the time when the release switch 30a is half-pressed as an imaging condition.

Here, in the "imaging period" shown in FIG. 2, both a period in which the release switch 30a is half-pressed to determine the imaging condition and a period in which the release switch 30a is fully pressed to perform the imaging are performed. I will include it. In addition,
The focus state is detected by a method such as CCD-AF utilizing an output signal from the CCD image pickup device 21, for example.

Incidentally, depending on the setting of the electronic camera 1 and the type of the electronic camera 1, there is a case where the AE lock is performed in addition to the AF lock (or instead of the AF lock) (note that "AE lock" is determined). The imaging condition to be performed is exposure, which is based on a combination of the shutter speed of a shutter (not shown), the charge accumulation time of the CCD image pickup device 21, the aperture value of an aperture stop (not shown), etc.).

When determining the exposure, for example, C
By using the output signal from the CD image sensor 21,
The brightness of the subject is measured. Next, in the reproduction mode, the image data already stored in the external storage device 26 (that is, the image data recorded in the past) is expanded in the compression / expansion circuit 24, and then displayed on the monitor 28 via the video circuit 27. This is the mode for playback display. At this time, the video circuit 27 continuously outputs the image data to the external storage device 2.
Output to 6.

That is, the image processing block 2a in the reproduction mode performs a simpler process than the image pickup period. Then, in this embodiment, as shown in FIG.
The system clock frequency of the image processing block 2a is set to a low speed f1 during the imaging preparation period in the imaging mode, a high speed f2 during the imaging period in the imaging mode, and a low speed f1 in the reproduction mode. .

Next, setting of the system clock frequency by the CPU 29 will be described with reference to FIG.
FIG. 3 is an operation flowchart of the CPU 29 of this embodiment.

The CPU 29 operates the electronic camera 1 as follows according to a program stored in advance in the ROM 29a. When the power switch is turned on (step S
1 YES), it is determined from the state of the mode changeover switch 30b and the like whether the mode is the reproduction mode or the imaging mode (step S2).

When it is determined that the mode is the image pickup mode (YES in step S2), the release switch 30a is further activated.
From the state of (3) or the like, it is determined whether it is the imaging period or the imaging preparation period (step S3). Then, when it is determined that it is the imaging preparation period (NO in step S3), the system clock frequency of the image processing block 2a is set to the low speed f1 (step S4), and then the above-described imaging preparation process (through image). Is displayed) (step S5).

If it is determined that it is during the image pickup period (YES in step S3), the system clock frequency of the image processing block 2a is set to high speed f2 (step S6), and then the above-described image pickup process (image) is performed. Data recording and the like) are performed (step S7). If it is determined that the reproduction mode is set (NO in step S2),
The system clock frequency is set to the low speed f1 (step S8), and then the above-described reproduction process (reproduction display of images recorded in the past, etc.) is performed (step S8).
9).

FIG. 4 is a timing chart for explaining how the system clock frequency of the image processing block 2a in this embodiment changes. Note that in FIG. 4, the release switch 3 is changed from the state in which the imaging mode is set.
0a is pressed halfway, and then the release switch 30
a is fully pressed, and then the mode changeover switch 30
An example is shown in which the reproduction mode is switched by the switching operation of b.

Note that FIG. 4 shows a waveform significantly lower than the actual clock frequency in order to show the change in the clock frequency in an easy-to-understand manner. Further, the relationship between the values of the system clock frequencies f1 and f2 is not limited to the relationship shown in FIG. 4, and may be at least the relationship of f1 <f2. Specific values of the actual system clock frequencies f1 and f2 are determined to be optimum values obtained in advance by experiments or the like.

As described above, the processing performed by the image processing block 2a in the reproduction mode and the image pickup preparation period is relatively simple, and is used by the user to confirm a through image or an image captured in the past. Mode. In this embodiment, the system clock frequency set in the reproduction mode and the imaging preparation period is the low speed f1.

At this time, the processing speed of the image processing block 2a is slightly reduced, but the power consumption during the processing is positively suppressed. On the other hand, as described above, the processing performed by the image processing block 2a during the imaging period is relatively complicated and is a mode for the user to perform imaging. In the present embodiment, the system clock frequency set during this imaging period is high speed f2.

At this time, the power consumption is somewhat increased, but the processing speed of the image processing block 2a is improved.
That is, in the present embodiment, the system clock is switched to an appropriate speed according to the necessity of each mode of the electronic camera 1. Therefore, the internal processing of the electronic camera 1 is made efficient as a whole.

As a result, both the reduction of the waiting time by the user and the extension of the battery life can be realized. Regarding the functions of the electronic camera 1 of the present embodiment during the imaging preparation period, only the display of a through image has been described, but functions such as AF (auto focus), AE (auto exposure), AWB (auto white balance), etc. Is added,
The monitor 28 may be turned on / off, a zoom operation may be possible, or communication with an external device may be possible.

In this embodiment, during the "imaging period",
Although both the period in which the release switch 30a is pressed halfway to determine the imaging condition and the period in which the release switch 30a is fully pressed to perform the imaging (see FIGS. 2 and 4), the imaging condition is determined. The period to be performed may be included in the imaging preparation period. In this case, the relationship between the mode of the electronic camera 1 and the system clock frequency is shown in FIG.
Instead of the image processing block 2a shown in FIG.
The state of the change of the system clock frequency is as shown in FIG. 6 instead of FIG.

Further, in the present embodiment, the target of switching the system clock frequency is the image processing block 2a which is a combination of the video circuit 27, the memory 23, and the compression / expansion circuit 24, but the module is composed of other combinations. May be Further, in the present embodiment, the switching means (CPU 29, frequency dividing circuit 32, clock generating circuit 31, etc.) is formed on the same IC as the switching target (image processing block 2a), but on a different IC. It may be formed in.

Further, in the present embodiment, the CPU 29 (CPU 29, ROM 29a, RA for switching is used.
The M29b) may be configured as a separate body from the CPU for sequence-controlling each unit of the electronic camera 1.
Further, in the present embodiment, the target of switching the system clock frequency is a single module, but it may be a plurality of modules.

However, with respect to the module including the memory 23, the compression / expansion circuit 24, and the video circuit 27, the processing speed required in the image pickup period and the processing speed required in other modes are very different from each other. It is preferably included in the target of switching the clock frequency.

<Second Embodiment> FIG. 1, FIG. 7, FIG. 8 and FIG.
The second embodiment of the present invention will be described with reference to FIG. Only the differences from the first embodiment will be described below. 8 and 9, the same elements as those in FIGS. 3 and 4 are designated by the same reference numerals. The configuration of the electronic camera of this embodiment is the same as that of the electronic camera 1 of the first embodiment shown in FIG. 1, but the processing by the CPU 29 is partly different (that is, the programs stored in the ROM 29a are partly different). . Further, the frequencies that can be set by the frequency dividing circuit 32 in the electronic camera of this embodiment are at least f1, f1 ′,
There are three types, f2.

FIG. 7 is a diagram for explaining the relationship between the mode of the electronic camera 1 set by the CPU 29 of the present embodiment and the system clock frequency. FIG. 8 is an operation flowchart of the CPU 29 of this embodiment. FIG. 9 is a timing chart illustrating how the system clock frequency of the image processing block 2a in this embodiment changes.

As shown in FIGS. 7, 8 and 9, in the electronic camera of this embodiment, the system clock frequency of the image processing block 2a is set to a low speed f1 during the imaging preparation period in the imaging mode, It is set to high speed f2 during the imaging period in the mode and low speed f2 in the reproduction mode.
1 '(f1 <f2, f1'<f2, f1 ≠
f1 ').

In FIG. 9, the release switch 30a is pressed halfway from the state where the image pickup mode has been set,
An example is shown in which the release switch 30a is fully pressed subsequently, and then the reproduction mode is switched by the switching operation of the mode switch 30b.

In FIG. 9, a waveform significantly lower than the actual clock frequency is shown in order to show the change in the clock frequency in an easy-to-understand manner. Further, the relationship of the values of the system clock frequencies f1, f2, f1 ′ is not limited to the relationship shown in FIG. 4, and at least f1 <f2, f1 ′ <f2, f
It suffices that the relationship of 1 ≠ f1 ′ (not necessarily f1> f1 ′).

The actual system clock frequency f
Specific values of 1, f2, and f1 'are determined to be optimal values obtained in advance by experiments or the like. As described above, in the present embodiment, unlike the first embodiment, the system clock frequency also differs between the reproduction mode and the imaging preparation period. According to the present embodiment as described above, the system clock can be switched more flexibly than in the first embodiment according to the necessity of each mode of the electronic camera 1. Therefore,
The internal processing of the electronic camera 1 can be made more efficient.

In FIGS. 7 and 9, during the "imaging period",
An example in which both the period in which the release switch 30a is pressed halfway to determine the imaging condition and the period in which the release switch 30a is fully pressed to perform imaging are shown, but the imaging condition is determined. The period may be included in the imaging preparation period. <Others> In the electronic cameras of the above-described embodiments, it is more preferable that the electronic camera operates as follows when a switch for turning on / off the monitor 28 by the user is provided.

That is, even in the same imaging preparation period,
While the through image is displayed when the monitor 28 is turned on, the through image is not displayed when the monitor 28 is turned off. Therefore, as shown in FIG. 10, during display of the through image during the imaging preparation period, The above-mentioned system clock frequency is set to f1, and during non-display of the through image during the imaging preparation period, the system clock frequency is set to f0, which is lower than f1 (f0 <f1).

Furthermore, in this electronic camera, the type of autofocus (AF) is set to continuous AF.
When a switch for switching between (the focusing operation is always performed during the imaging preparation period) and single AF (the focusing operation is performed only when the release switch 30a is half-pressed) is provided. More preferably, the electronic camera operates as follows.

That is, even in the same imaging preparation period,
Since the former process requires more complicated processing when continuous AF is set and when single AF is set, as shown in FIG. 11, a through image is displayed during the imaging preparation period. When single AF is set, the system clock frequency is f
When it is set to 1 and continuous AF is set, the system clock frequency is set to f01, which is slower than f1.

When the through image is not displayed during the image pickup preparation period, single AF is set regardless of the user's setting, so the system clock frequency is set to f0, which is a lower speed (f0 <f01 <f1). ). Further, in each of the above embodiments, the system clock frequency may be switched between modes other than those described above.

[0053]

As described above, according to the present invention,
In electronic cameras, shortening the waiting time by the user,
It has become possible to achieve both extended battery life.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an electronic camera according to a first embodiment.

FIG. 2 is a diagram illustrating a relationship between a mode of the electronic camera 1 set by a CPU 29 of the first embodiment and a system clock frequency.

FIG. 3 is an operation flowchart of a CPU 29 of the first embodiment.

FIG. 4 is a timing chart illustrating how the system clock frequency of the image processing block 2a in the first embodiment changes.

FIG. 5 is a diagram illustrating another example of the relationship between the mode of the electronic camera 1 and the system clock frequency set by the CPU 29.

FIG. 6 is a timing chart illustrating another example of how the system clock frequency of the image processing block 2a changes.

FIG. 7 is a diagram illustrating a relationship between a mode of the electronic camera 1 set by a CPU 29 of the second embodiment and a system clock frequency.

FIG. 8 is an operation flowchart of the CPU 29 of the second embodiment.

FIG. 9 is a timing chart illustrating how the system clock frequency of the image processing block 2a in the second embodiment changes.

FIG. 10 is a diagram illustrating still another example of the relationship between the mode of the electronic camera 1 and the system clock frequency.

FIG. 11 is a diagram illustrating still another example of the relationship between the mode of the electronic camera 1 and the system clock frequency.

[Explanation of symbols]

1 electronic camera 2 Image processing IC 2a Image processing block 11 lenses 13 Lens drive 21 CCD image sensor 22a Analog signal processing circuit 22b A / D conversion circuit 23 memory 24 compression / expansion circuit 25 connector 26 External storage device 27 video circuits 28 monitors 29 CPU 29a ROM 29b RAM 30a Release switch 30b Mode selector switch 31 Clock generation circuit 32 frequency divider

Claims (10)

[Claims] 1. An electronic camera capable of switching to a plurality of modes in which mutually different processes are executed, comprising switching means for switching a system clock frequency inside the electronic camera in accordance with the switching of the modes. And electronic camera. 2. The electronic camera according to claim 1, wherein the mode includes an imaging mode in which imaging is performed to acquire image data and a non-imaging mode in which other processing is performed, and the switching unit is configured to An electronic camera, wherein the clock frequency in the imaging mode is set higher than the clock frequency in the non-imaging mode. 3. The electronic camera according to claim 2, wherein the image pickup condition is determined in the image pickup mode. 4. The electronic camera according to claim 2, wherein the imaging condition is determined in the non-imaging mode. 5. The electronic camera according to claim 2, wherein the non-imaging mode is a reproduction mode in which an image obtained by past imaging is reproduced and displayed, and a process other than the reproduction mode. The electronic device is characterized in that the switching means sets the clock frequency in the reproduction mode and the clock frequency in the non-imaging non-reproduction mode to different values from each other. camera. 6. An electronic camera provided with an operating member for an operator to perform an operation, comprising switching means for switching a system clock frequency inside the electronic camera according to an operation of the operating member. Electronic camera to do. 7. The electronic camera according to claim 6, wherein the operation member is a release button for causing the electronic camera to take an image, and the switching unit is the clock frequency when the release button is operated. Is set to be higher than the clock frequency when the release button is not operated. 8. The electronic camera according to claim 7, wherein the operation member is a release button that causes the electronic camera to take an image at the time of full-press operation and causes the electronic camera to determine an imaging condition at the time of half-press operation. The electronic camera is characterized in that the switching means sets the clock frequency when the release button is fully pressed and half-pressed to be higher than the clock frequency when the release button is not operated. 9. The electronic camera according to claim 7, wherein the operation member is a release button that causes the electronic camera to take an image at the time of full-press operation and causes the electronic camera to determine an imaging condition at the time of half-press operation. The electronic camera is characterized in that the switching means sets the clock frequency when the release button is fully pressed to be higher than the clock frequency when the release button is half-pressed and not operated. 10. The electronic camera according to claim 7, wherein, as the operation member, the operation of imaging by the release button is invalidated, and a reproduction display is displayed on the electronic camera. A reproduction setting member for performing the reproduction setting member is further provided, and the switching unit includes the clock frequency when the reproduction setting member is set and the clock frequency when the reproduction setting member is not set and the release button is not operated. An electronic camera characterized in that and are set to different values.