JP2004117845A - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device which improves the capability of identifying a falling state. <P>SOLUTION: A grip part 17 of a digital camera 10 is provided with a pressure sensor 18, so that a grip pressure at the time of photographer's grasping the digital camera 10 can be measured. By determining a fall based on the measurement result of the pressure sensor 18 it is easy to discern between shake and fall because the digital camera 10 is grasped by the photographer it is shaken even, and the camera 10 is not grasped when falling. When it is determined as a fall, a lens barrel 22 is contracted to collapse a lens 20 into a camera body, and a lens barrier 16 is switched from an open state to a close state to protect the lens 20, and thus the lens is more surely protected from an impact caused by a fall. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image pickup apparatus, and more particularly to an image pickup apparatus having a protection function for taking a subject image through a lens and protecting the lens from an impact caused by dropping.
[0002]
[Prior art]
Conventionally, in an imaging apparatus with an optical zoom function, a retractable lens has been adopted as a photographic lens. A zoom lens group and a focus lens group are housed in a lens barrel retracted in a housing, and a power source When is turned on, the lens barrel is extended to a predetermined reference position by a motor to set the zoom lens group to the wide side, and the zoom lens group is supported in the space formed inside the housing by the extension of the lens barrel. The autofocus lens group is moved to the position where it has been taken, and the camera enters a standby state where photographing can be performed.
[0003]
An image pickup apparatus employing such a retractable lens can be stored in the main body, so that the lens can be protected from scratches and is excellent in portability, but on the other hand, the lens barrel is extended. However, if an external force is applied by dropping or the like, the cam follower pin may come off from the cam groove of the lens, which may cause damage.
[0004]
For this reason, conventionally, there has been proposed a technique in which a sensor for detecting vibration (blur) is provided in a camera and the lens is retracted and protected when vibration that is presumed to be dropped is detected (see Patent Document 1). ).
[0005]
[Patent Document 1]
JP-A-9-61869
[0006]
[Problems to be solved by the invention]
However, it is difficult to discriminate the difference between falling and camera shake only by detecting vibration, and the conventional technology determines that it is falling when vibration exceeding the threshold is detected. There was a possibility of misjudgment that the setting was not appropriate. That is, when the camera is dropped, it is erroneously determined as camera shake, so that the lens is not protected, or it is erroneously determined that the camera is dropped even though it is a simple camera shake, and shooting is stopped.
[0007]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an imaging apparatus capable of improving the fall state identification ability.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is an imaging device having a protection function for capturing a subject image through a lens and protecting the lens from an impact caused by dropping. A pressure detection means for detecting the pressure applied when gripped by the sensor, and whether or not the imaging device is falling, based on the detection result by the pressure detection means, and when it is determined to fall Includes a protection control means for controlling the protection function to operate.
[0009]
According to the first aspect of the present invention, it is possible to detect that the imaging device is gripped by the photographer by providing the photographer with pressure detection means for detecting the gripping pressure. Even when a camera shake occurs, the photographer holds the camera and does not hold the camera when the camera is dropped. Therefore, the pressure detection unit can easily distinguish between camera shake and a camera drop. The protection control means makes a drop determination based on the detection result of the pressure detection means, and when it is determined that the lens is falling, the protection control means protects the lens by a protection function and protects the lens from an impact caused by the drop. For example, in the case where the lens is a retractable lens whose lens barrel can be expanded and contracted in the optical axis direction and can be stored in the main body of the imaging device by contraction of the lens barrel, the lens barrel is extended from the main body. If it is in a protruding state, it is easily damaged by an impact at the time of dropping. Therefore, as described in claim 7, the lens may be housed in the main body by the protective function.
[0010]
As described above, since the fall determination is performed based on the detection result of the pressure detecting means capable of distinguishing between the camera shake and the fall, the fall discrimination ability can be improved as compared with the conventional one, and the lens can be more reliably protected from the impact caused by the fall. Can be protected.
[0011]
The drop determination may be performed by comparing the detection result by the pressure detection unit with a preset value uniformly regardless of the photographer, but the gripping force differs for each photographer. For this reason, the invention according to claim 2 further includes setting means for setting a reference value used for drop determination for each photographer based on a detection result by the pressure detection means, and the protection control means The fall detection is performed by comparing the detection result by the pressure detection means with the reference value set by the setting means. According to the invention described in claim 2, since the reference value is set for each inventor and the fall determination is performed, there is an effect of preventing erroneous determination.
[0012]
By the way, in addition to the gripping by the photographer, the imaging apparatus may be used with its position fixed by using a tripod or placing it on a table. Therefore, the invention according to claim 3 is for selecting one of the first mode for executing the control of the protection control means and the second mode for not executing the control of the protection control means. It further has the selection means. Thereby, the photographer can select the mode according to his / her usage pattern (use and use without holding).
[0013]
According to a fourth aspect of the present invention, the image pickup apparatus further includes a fixing detection unit that detects that the position of the imaging device is fixed by a fixing member, and the protection control unit is configured to detect the position by the fixing detection unit. If the fixing of the position of the imaging device is detected, the control may be stopped. Thereby, when the position of the imaging device is fixed by a fixing member such as a tripod or a stand, the protection control means automatically stops the control, so that the mode change operation of the photographer is not required. It is also possible to prevent erroneous determination when the mode switching operation is forgotten.
[0014]
According to a fifth aspect of the present invention, the abnormality determination means for executing a predetermined function test to determine the presence or absence of abnormality of the lens after the protection function is operated by the protection control means, and the abnormality determination And a notifying means for notifying the determination result by the means. As a result, after it is determined that the lens has been dropped and the lens is protected, a predetermined function test is performed by the abnormality determination unit to determine whether the lens is abnormal. If there is an abnormality, the notification unit notifies the user. Accordingly, when the photographer accidentally drops the imaging device, the photographer can confirm whether or not the lens is damaged due to the drop by the notification of the notification means.
[0015]
In this case, as described in claim 6, the apparatus further includes a history storage unit that stores the history information of the determination by the abnormality determination unit, and accumulates a function test result history when the imaging device is dropped. This will help you investigate the cause of the failure when repairing.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, an example of an embodiment according to the present invention will be described in detail with reference to the drawings. Hereinafter, a case where the present invention is applied to a digital still camera will be described as an example, but the present invention can also be applied to a silver salt camera, a digital video camera, and the like.
[0017]
As shown in FIG. 1, the front surface of a digital still camera (hereinafter abbreviated as “digital camera”) 10 to which the present invention is applied emits light when the subject has a low illuminance at which an appropriate amount of exposure light cannot be obtained. A strobe 12, a finder window 14 into which light showing an image substantially equivalent to a subject image to be photographed enters, and an openable / closable lens barrier 16 for protecting the lens are provided.
[0018]
In addition, a pressure sensor 18 as pressure detecting means is provided on the grip portion 17 at the front left end of the digital camera 10 so that the gripping pressure when the photographer is gripping the digital camera 10 can be measured. ing. The pressure sensor 18 only needs to be able to detect a change in pressure. For example, a sensor whose electrical resistance changes when the pressure changes can be used. Further, the present invention does not particularly limit the attachment position of the pressure sensor 18. However, the position where the right or left hand contacts to hold the digital camera without taking an unnatural posture at the time of shooting is preferably provided in the grip portion 17 as in the present embodiment. .
[0019]
In addition, a lens 20 for forming a subject image is retracted in the body of the digital camera 10, and at the time of photographing, the lens barrier 16 is opened as shown in FIG. The lens barrel 22 that can be expanded and contracted in the direction is extended so that the retracted lens 20 appears outside.
[0020]
This lens 20 is configured by attaching a zoom lens group and an autofocus lens group (not shown) in a lens barrel 22, and the zoom lens group moves in the optical axis direction along with the expansion and contraction of the lens barrel 22, and a desired lens 20 is arranged. It is set to the position where the zoom magnification is achieved (focal length variable lens). On the other hand, the autofocus lens group is attached to a focus lens frame attached to a lens frame that holds a part of the lenses of the zoom lens group. The focus lens frame is movable along the optical axis direction, and the auto focus lens group moves the auto focus lens group frame so that incident light indicating a subject image that has passed through the lens is an image sensor described later. It is set at a position where an image is formed on the light receiving surface (autofocus (AF) mechanism).
[0021]
In this embodiment, the lens 20 including the zoom lens group and the autofocus lens group (that is, the AF mechanism and the focal length variable lens) will be described as an example, but only the AF mechanism is provided instead of the zoom lens group. It is also possible to use a fixed focal length lens.
[0022]
Also, on the upper surface of the digital camera 10, a power switch 24 for switching supply / stop of power supply to each part of the digital camera 10 and a photographing instruction button are pressed by a photographer when performing photographing. A shutter switch (so-called release button) 26 to be operated and a mode changeover switch 28 as selection means to be operated when selecting an operation mode of the digital camera 10 are provided. In the present embodiment, the mode selector switch 28 selects either the lens protection mode as the first mode or the normal mode as the second mode.
[0023]
Further, on the side of the digital camera 10, a slot (illustrated) for loading a portable recording medium (in this embodiment, smart media) that stores image data obtained by shooting as digital data into the digital camera 10. (Omitted) is provided. Also, on the back of the digital camera 10, a liquid crystal display 32 (see FIG. 2, not shown in FIG. 1) for displaying a subject image obtained by shooting, various menus, parameters relating to image processing, messages, and the like, and a liquid crystal A cursor button 36 (see FIG. 2; not shown in FIG. 1) for selecting a desired menu item or parameter from the menu screen displayed on the display 32 and instructing up / down of the photographing magnification, and the finder window 14 A viewfinder eyepiece (not shown) is provided that is guided through an optical member (not shown) and is viewed by the photographer when determining the composition of the subject to be photographed.
[0024]
Next, the configuration of the electrical system of the digital camera 10 according to the present embodiment will be described with reference to FIG.
[0025]
As shown in the figure, the digital camera 10 includes a CCD (Charge Coupled Device) 40 that captures an object based on incident light indicating a subject image that has passed through a lens 20 and outputs an analog image signal indicating the subject image, and an input. An analog signal processing unit 42 that performs predetermined analog signal processing on the received signal, and an analog / digital converter (hereinafter referred to as “A / D converter”) 44 that converts the input analog signal into a digital signal. A digital signal processor (DSP) 46 that performs predetermined digital signal processing on the input digital signal, and an SDRAM (Synchronous Dynamic Random Access Memory) 48 that stores information indicated mainly by a digital signal indicating a subject image. A flash ROM (Flash Read Only Memory) 50 for storing various programs, predetermined data, and the like, and a driving means for moving the lens 20 (for example, a motor for expanding and contracting the lens barrel 22 in the optical axis direction, A motor drive 52 for driving the autofocus lens group in the optical axis direction), a motor drive 54 for driving a motor (not shown) for opening and closing the lens barrier 16, and a CCD control for driving the CCD 40. A unit 56, a strobe control unit 58 for causing the strobe 12 to emit light, and a recording media interface (I / F) 60 for reading and writing recording media loaded in the slot.
[0026]
The digital camera 10 further includes a CPU (Central Processing Unit) 62 that controls the operation of the entire digital camera 10.
[0027]
The CPU 62 is connected to the main bus MB together with the SDRAM 48 and the flash ROM 50, and the CPU 62 can arbitrarily access the SDRAM 48 and the flash ROM 50. The CPU 62 is connected to operation means operated by the photographer such as the power switch 24, the shutter switch 26, the mode switch 28, and the cursor button 36. The CPU 62 can always grasp the operation state of the operation means by the photographer. The CPU 62 is also connected to the pressure sensor 18 to turn on / off the pressure sensor 18 and to grasp the gripping state of the digital camera 10 by the photographer when the pressure sensor 18 is on.
[0028]
Further, the CPU 62 is connected to the liquid crystal display 32, the DSP 46, the motor drive 52, the motor drive 54, the CCD control unit 56, the strobe control unit 58, and the recording medium I / F 60. The operations of these units are controlled according to the operating state and the gripping state of the digital camera 10 by the photographer.
[0029]
Specifically, in the digital camera 10 according to the present embodiment, when the power is turned off, the lens 20 is retracted and the lens barrier 16 is also closed. When the power is turned on by the operation of the power switch 24, The motor drive 54 drives the motor to open the lens barrier 16, and then the motor drive 52 drives the motor to extend the lens barrel 22 to move the zoom lens group to a preset magnification. That is, when the power is turned on, the lens barrier 16 is opened, and the lens barrel 22 of the lens 20 is protruded.
[0030]
At the time of shooting, the CCD controller 56 causes the CCD 40 to shoot a subject image at a predetermined timing. At this time, in response to an input of an imaging magnification up / down instruction by the cursor button 36, the motor drive 52 is driven to drive the motor to expand / contract the lens barrel 22, thereby changing the imaging magnification.
[0031]
When a subject image is taken by the CCD 40, an analog image signal indicating the subject image is output from the CCD 40. The output terminal of the CCD 40 is an input terminal of the analog signal processing unit 42, the output terminal of the analog signal processing unit 42 is an input terminal of the A / D converter 44, and the output terminal of the A / D converter 44 is an input of the DSP 46. Each is connected to the end.
[0032]
The analog image signal indicating the subject image output from the CCD 40 is subjected to predetermined analog signal processing by the analog signal processing unit 42, and then converted into a digital image signal by the A / D converter 44, and then predetermined by the DSP 46. Digital signal processing is performed and the digital image data is temporarily stored in the SDRAM 48.
[0033]
The DSP 46 is also connected to the recording medium I / F 60 and the liquid crystal display 32, and the digital image data stored in the SDRAM 48 is compressed by a compression / decompression circuit (not shown) as necessary, via the DSP 46. Are recorded on the smart media attached to the recording media I / F 60. Note that. Capture of digital image data for recording is performed in response to an input of a shooting / recording instruction by the shutter switch 26. More specifically, the motor drive 52 is driven by half-pressing the shutter switch 26 to drive the motor to the autofocus lens group. The subject is focused and a subject image is photographed by full depression, and the digital image data obtained by photographing is recorded on the smart media.
[0034]
Further, the DSP 46 displays the moving image based on the digital image data obtained by continuous imaging by the CCD 22 as a so-called through image on the liquid crystal display, so that the liquid crystal display 32 can be used as an electronic viewfinder.
[0035]
Further, at the time of image reproduction, digital image data to be reproduced stored in the smart media is read by the DSP 46, decompressed by a compression / decompression circuit (not shown), and displayed on the liquid crystal display 32.
[0036]
When the power is turned off, the motor drive 52 drives the motor so that the lens 20 is stored inside the digital camera 10, and then the motor drive 54 is driven so that the lens barrier 16 is closed. After driving, the lens 20 is retracted and accommodated in the housing, and after the lens barrier 16 is closed, the power is turned off. As for the control when the power is turned off, the CPU 62 is provided with a timer 64 for measuring the elapsed time as well as when the power is turned off by the operation of the power switch 24 by the photographer. The measurement is also performed when the auto power function is activated without any operation by the photographer for a predetermined time. Note that the timer 64 may not be built in the CPU 60, and a timer provided separately from the CPU 60 and connected to the CPU 60 may be used.
[0037]
Further, in the digital camera 10 of the present embodiment, even when the power is turned on, when the result of measurement by the pressure sensor 18 detects that the photographer has changed the gripping state to the non-holding state, the CPU 62 performs the digital camera 10. Assuming that the camera 10 is falling, the motor drives 52 and 54 drive the motor, the lens 20 is retracted and accommodated in the housing, the lens barrier 16 is closed, and the lens 20 is protected. . In this embodiment, the power is temporarily turned off at this time. In addition, the CPU 62 measures the gripping force of the grip part by the photographer with the pressure sensor 18 for the threshold value for distinguishing between the gripping state and the non-gripping state, that is, the reference value used for the drop determination, and is appropriate for each photographer. The value is set and used. Therefore, the CPU 62 functions as a protection control unit and a setting unit of the present invention.
[0038]
Further, in the digital camera 10 of this embodiment, after the lens 20 is determined to have fallen and the lens 20 is protected, the CPU 62 causes the motor drives 52 and 54 to drive the motor to perform a function test of the lens 20. Inspect whether the lens 20 can be used normally, that is, whether or not the lens 20 is abnormal due to the dropping, and the result is displayed on the liquid crystal display 32 to notify the photographer or the flash ROM 50 as test history information. Or remember. That is, the CPU 62 also functions as the abnormality determination unit of the present invention, and the liquid crystal display 32 and the flash ROM 50 are used as the notification unit and history storage unit of the present invention.
[0039]
In the present embodiment, the liquid crystal display 32 that is generally provided in the digital camera is used as a notification unit. However, there is an imaging device that does not include the liquid crystal display 32, such as a silver halide camera, Warning warning may be performed by turning on a warning lamp or outputting a warning sound from a speaker.
[0040]
Next, the operation of the present embodiment will be described. When the photographer uses the digital camera 10 of the present embodiment, the photographer turns on the power by operating the power switch 24 and operates the mode switch 28 to select from the normal mode and the lens protection mode. Select the desired operating mode.
[0041]
The digital camera 10 of the present embodiment is activated by a power ON operation of the power switch 24. FIG. 3 shows a control routine (mainly processing according to the present invention) performed by the CPU 62 after activation.
[0042]
As shown in FIG. 3, when the power of the digital camera 10 is turned on, the lens barrier 16 is first closed to open in step 100 under the control of the CPU 62, and the lens barrel 22 is extended by a predetermined length. Projecting from the main body of the digital camera 10. As the lens barrel 22 expands at this time, the zoom lens group inside the lens barrel 22 moves in the optical axis direction and is set to a predetermined photographing magnification.
[0043]
If the normal mode is selected by the mode switch 28, a negative determination is made in the next step 102, the process proceeds to step 104, the mode is changed to the normal mode, and the operating means (mainly the shutter switch 26 and the In response to the operation of the cursor button 36), a subject image is shot, a shot image is played back, and the like until the operation mode is switched or the power OFF is instructed through the following steps 106 to 108. Returning to step 104, shooting and image reproduction according to the operation of the operation means (mainly the shutter switch 26 and the cursor button 36) by the photographer are continued. During this period, the pressure sensor 18 remains OFF.
[0044]
Specifically, at this time, if the photographer wants to perform photographing, he / she operates a changeover switch (not shown) to select a photographing mode, and uses an optical finder (light entering from the finder window 14 in FIG. (It is realized by guiding to the finder eyepiece (not shown) on the back of the camera 10) or while confirming the subject with the liquid crystal viewfinder, the cursor button 36 is operated as necessary to change the photographing magnification, The composition is determined and the shutter switch 26 is pressed.
[0045]
Thus, digital image data indicating the subject image is generated by the DSP 46 and temporarily stored in the SDRAM 48. Thereafter, the digital image data is read from the SDRAM 48 by the DSP 46 and displayed on the liquid crystal display 32, and is compressed by a compression / expansion means (not shown) into image data of a predetermined format such as a JPEG format, and then recorded. It is stored in the smart media via the media I / F 60.
[0046]
When the photographer wants to reproduce and display an already captured image on the liquid crystal display 32, the photographer operates a changeover switch (not shown) to switch to the reproduction mode and operates the cursor button 36 to display digital image data to be reproduced. When designated, the designated digital image data is read from the smart media by the recording medium I / F 60 and decompressed by a compression / expansion means (not shown), and then an image based on the digital image data is displayed on the liquid crystal display 32. Is done.
[0047]
Thereafter, when the photographer operates the mode switch 28 to switch the operation mode from the normal mode to the lens protection mode, an affirmative determination is made in step 106 and the process returns to step 102. Further, when the power switch 24 is operated by the photographer, or when the auto power-off function is activated after a predetermined time has elapsed since the last operation and the power-off is instructed, an affirmative determination is made in step 108, which will be described later. Proceed to step 150.
[0048]
On the other hand, if the lens protection mode is selected by the mode switch 28, an affirmative determination is made in step 102, the lens protection mode is entered, the process proceeds to step 110, and the pressure sensor 18 is first turned on. Thereby, pressure measurement is started. In the next step 112, when the measurement result (pressure measurement value) by the pressure sensor 18 is equal to or greater than a preset initial value, the photographer recognizes that the grip portion of the digital camera 10 has been gripped, and Proceed to step 114. This initial value indicates a pressure measurement value by the pressure sensor 18 when not in the gripping state, and is stored in the flash ROM 50 in advance.
[0049]
In step 114, the pressure measurement by the pressure sensor 18 is performed for a predetermined time (several seconds), and the gripping force of the grip by the photographer is measured. Then, in step 116, based on the measurement result, the drop is determined. Set the threshold. For example, an average value AVR of pressure measurement results for a predetermined time is calculated, and the threshold value is TH, and TH = AVR ± δ or TH = AVR × δ, for example, a predetermined value or a predetermined proportion of the average value AVR. The threshold is set so that the fluctuation is allowed.
[0050]
As described above, when the mode is shifted to the lens protection mode, the photographer always recognizes gripping of the grip portion, and the threshold is set based on the measurement result of the gripping force. Is possible.
[0051]
After the threshold value is set, the process proceeds to the next step 118, and the pressure sensor 18 remains ON, that is, the pressure sensor 18 measures the gripping pressure of the grip portion by the photographer, as in the normal mode. In accordance with the operation of the operation means (shutter switch 26 and cursor button 36) by the user, shooting of the subject image, reproduction of the shot image, and the like are performed. Then, based on the measurement result (pressure measurement value) of the pressure sensor 18, while it is determined that the grip portion is gripped by the photographer, the operation mode is not switched or the power OFF is not instructed. From the next step 120, the process returns to step 118 via steps 122 and 124, and the shooting and image reproduction according to the operation of the operation means (mainly the shutter switch 26 and the cursor button 36) by the photographer are continued. At this time, even if camera shake occurs, since the grip portion is held by the photographer, photographing of the subject image and image reproduction are continued. When the photographer switches the operation mode from the lens protection mode to the normal mode, the process returns from step 122 to step 102, and when the power OFF is instructed, the process proceeds from step 124 to step 150 to be described later.
[0052]
On the other hand, if the measurement result (pressure measurement value) of the pressure sensor 18 is equal to or less than the threshold value set in step 116 during the photographing / reproduction processing period in the lens protection mode, it is determined that the digital camera 10 is in the fall state. Then, the process proceeds from step 120 to step 130.
[0053]
In step 130, the lens barrel 22 is contracted to retract the lens 20 into the camera body, and the lens barrier 16 is opened to closed to protect the lens 20. At this time, the upper limit of the retracting speed of the lens 20 is canceled, and the lens 20 is retracted at the retracting speed at the limit of the driving capability (fastest retracting).
[0054]
Thereafter, the power is turned off in step 132, and then the power is turned on in step 134 to restart the digital camera 10. After the restart, first, in step 136, a function test is performed to inspect whether the lens 20 is abnormal due to dropping or not. This functional test can be performed, for example, by measuring the protrusion / collapse time of the lens 20 with the timer 64 by extending and contracting the lens barrel 22 with a normal driving capability. If it takes a long time to retract, it may be determined that an abnormality has occurred.
[0055]
If an abnormality is detected by this function test, the process proceeds from the next step 138 to step 140 to notify the photographer of the abnormality by displaying an error message on the liquid crystal display 32, and then proceeds to step 142. If no abnormality is detected by the test, the process proceeds from step 138 to step 142 as it is.
[0056]
In step 142, the result of the function test is stored in the flash ROM 50 as a test history. Information stored as the test history at this time includes, for example, a function test execution date and time, a function test result (absence / absence of abnormality), and a time taken for the lens 20 to protrude or retract when an abnormality is detected.
[0057]
Thereafter, in step 144, the lens barrel 22 is extended by a predetermined length and protruded from the main body of the digital camera 10, that is, after setting to a predetermined photographing magnification, the process returns to step 102 and the same processing is repeated.
[0058]
On the other hand, when the power OFF is instructed and the affirmative determination is made in step 108 or step 124 described above and the process proceeds to step 150, the lens barrel 22 is contracted to retract the lens 20 into the camera body, and the lens barrier 16 is opened. → After the closed state, the power is turned off in the next step 152. Thereby, the control by the CPU 62 in FIG. 3 is terminated, and the operation of the digital camera 10 is terminated.
[0059]
Thus, in this embodiment, by providing the pressure sensor 18 in the grip portion of the digital camera 10, it can be detected that the digital camera 10 is gripped by the photographer. The camera is held by the photographer even when the camera shake occurs, and is not held when the camera is dropped. Therefore, the camera shake and the camera drop can be easily distinguished by the measurement result of the pressure sensor 18. By performing the fall determination based on the measurement result of the pressure sensor 18, the ability of the digital camera 10 to identify the fall is improved as compared with the conventional case, and the lens 20 can be more reliably protected when dropped.
[0060]
In addition, after this lens protection is performed, a function test is automatically performed to inspect whether the lens 20 is abnormal due to the fall, and if there is an abnormality, a notification is given. Can grasp the presence or absence of failure when it falls. In this embodiment, only the case where there is an abnormality is notified as the determination result based on the function test result. However, when there is no abnormality, the fact that it can be normally used is notified. Alternatively, notification may be performed both when there is an abnormality and when there is no abnormality. In addition, since the result of this function test is stored as history information, the repairer can use this history information for investigation of the cause of damage when the digital camera 10 is repaired.
[0061]
In the present embodiment, the case where the drop determination is performed by setting a threshold value that is a reference value for the drop determination for each photographer has been described as an example, but a preset threshold value is uniformly used regardless of the photographer. You may perform fall determination. However, the gripping force of the grip part differs for each photographer, and in particular, when a person with weak gripping power is shooting, there is a possibility that it will be erroneously determined as falling despite being gripped. It is preferable to set the threshold value by measuring the gripping force for each photographer as in the embodiment. In addition, in order to end the protection operation of the lens 20 such as the retracting of the lens 20 or closing the lens barrier 16 before the dropped camera reaches the ground or the like, it is required to detect the fall early, and the photographer By performing the fall determination using the threshold value set for each time, it is possible to immediately detect the fall at the moment of leaving the photographer's hand.
[0062]
In the above description, the case where the threshold value is set by measuring the gripping force of the photographer when the lens protection mode is selected and the mode is shifted to the mode has been described. However, the present invention is limited to this. Instead of this, a threshold value may be stored for each photographer, and this threshold value may be read out and used for drop determination at the time of shifting to the lens protection mode. This can be realized, for example, by performing processing as shown in FIG. In FIG. 4, the same processes as those in FIG. 3 are given the same step numbers, and detailed description thereof is omitted here.
[0063]
That is, as shown in FIG. 4, when the power is turned on, the lens barrier is closed to open, the lens barrel 22 is extended and the lens 20 is projected, and then the lens protection mode is selected by the mode changeover switch 28. If so, the process proceeds from step 102 to step 200. In step 200, an input screen for inputting the photographer's name is displayed on the liquid crystal display 32, and the input of the photographer's name is accepted. Here, the case where the photographer name is input will be described as an example. However, if the photographer can be identified, information other than the photographer name may be input.
[0064]
When the photographer name is input by operating the cursor button 36 by the photographer, in the next step 202, it is determined whether or not a threshold corresponding to the input photographer name is registered. In step S204, the threshold value setting process shown in FIG.
[0065]
As shown in FIG. 5, in this threshold value setting process, first, in step 220, the pressure sensor 18 is turned on and pressure measurement is started. Then, in the next step 222, as in step 112 in FIG. 3, when the measurement result (pressure measurement value) by the pressure sensor 18 is equal to or greater than a preset initial value, the photographer moves the grip portion of the digital camera 10 on. The process proceeds to the next step 224 by recognizing that it has been gripped.
[0066]
In step 224, as in step 114 of FIG. 3, the pressure measurement by the pressure sensor 18 is performed for a predetermined time (several seconds) to measure the gripping force of the grip by the photographer, and in the next step 226, the gripping force of FIG. As in step 116, a threshold for drop determination is determined based on this measurement result. In step 228, the determined threshold value is associated with the photographer name, and stored as a threshold value storage unit, for example, in the flash ROM 50, and the threshold value setting process ends. At this time, the pressure sensor 18 remains ON.
[0067]
Thereafter, the process proceeds to step 118 in FIG. 4, and thereafter, the same processing as in FIG. 3 is performed. In this case, the threshold value set by the threshold value setting process is used in the fall determination at step 120.
[0068]
On the other hand, in the case of a photographer who has previously set a threshold value by the threshold setting process, threshold information associated with the photographer's name is stored in the flash ROM 50. If entered, it is determined in step 202 that the threshold has been registered, and the process proceeds to step 206 where the threshold corresponding to the photographer name is read from the flash ROM 50. In the next step 208, the pressure sensor 18 is turned on to start pressure measurement, and then the process proceeds to step 118. Thereafter, the same processing as in FIG. 3 is performed. In this case, the threshold value read in step 206 is used for the fall determination in step 120.
[0069]
As described above, by making it possible to store the threshold value set for each photographer, it is not necessary to set the threshold value every time, and the load of the arithmetic processing of the CPU 62 can be reduced. In addition, it is not necessary to receive gripping force measurement for setting the threshold every time before photographing, and the waiting time until the photographing is started can be shortened.
[0070]
By the way, the photographer does not hold the digital camera 10 but uses a tripod or places it on a table such as a table to fix the position of the digital camera 10 and perform shooting and image reproduction. In some cases. In consideration of this, in the above, a lens protection mode which is a dedicated mode for performing the fall determination by turning on the pressure sensor 18 is prepared as the photographing mode, separately from the normal mode, and the pressure sensor 18 is used. The photographer can select whether or not to perform lens protection control based on the drop determination. That is, when using a tripod or mounting on a table, the photographer may operate the mode switch 28 to select the normal mode.
[0071]
Note that the digital camera 10 may automatically determine whether or not a drop determination using the pressure sensor 18 is necessary. For example, as shown by a dotted line in FIG. 2, a tripod sensor 70 for detecting the use of a tripod or a mounting sensor 72 for detecting that it is mounted on a table is connected to the CPU 60 as a fixed detection means. The CPU 60 can always know whether a tripod is used and whether it is placed on a table, and when a tripod is used or placed on a table is detected, the measurement by the pressure sensor 18 is automatically turned off and a lens based on drop determination is provided. This can be realized by stopping the protection control.
[0072]
The tripod sensor 70 used in this case is not particularly limited in its type and installation position as long as it can be detected that the tripod is attached to the digital camera 10. For example, a pressure change is detected in a tripod screw hole to which a male screw of a tripod generally provided on the bottom surface of the digital camera 10 is screwed, and at a portion pressed by the tip of the screwed male screw. Use of a tripod can be detected by providing a pressure sensor.
[0073]
Further, the type and installation position of the mounting sensor 72 used in this case are not particularly limited as long as it is possible to detect that the digital camera 10 is mounted and supported on something. For example, when the digital camera 10 is placed on a table such as the bottom, a pressure sensor that detects a change in pressure can be detected at a location where the digital camera 10 comes into contact with the table.
[0074]
Thus, by providing the tripod sensor 70 and the mounting sensor 72, when the photographer forgets to switch the shooting mode to the normal mode when using the tripod or mounting on the table, it is erroneously determined that the camera is dropped. Can be prevented. In other words, it is not necessary to prepare a dedicated mode in which the pressure sensor 18 is turned on and the drop determination is performed.
[0075]
In the above description, the case where the lens 20 is set to the protruding state when the power is turned on, both during shooting and during image playback, has been described as an example. You may make it retract. That is, since the lens 20 is not necessary except during photographing, it is preferable to retract the lens 20 in this way from the viewpoint of protecting the lens 20. In this case, if the lens barrier 16 is closed, the lens protection effect is higher.
[0076]
【The invention's effect】
As described above, the present invention has an excellent effect of being able to improve the ability to identify a fall state.
[Brief description of the drawings]
FIGS. 1A and 1B are perspective views showing an appearance (front surface) of a digital still camera according to an embodiment of the present invention in a state where a zoom lens is housed in the main body and FIG. FIG.
FIG. 2 is a block diagram showing a configuration of an electric system of the digital still camera according to the present embodiment.
FIG. 3 is a flowchart showing a control routine executed by the CPU of the digital still camera when the power is turned on.
FIG. 4 is a flowchart showing another example of a control routine (main routine) executed by the CPU of the digital still camera when the power is turned on.
FIG. 5 is a flowchart showing a threshold setting process (subroutine) executed by the CPU of the digital still camera.
[Explanation of symbols]
10 Digital still camera
16 Lens barrier
17 Grip part
18 Pressure sensor
20 lenses
22 Tube
24 Power switch
26 Shutter switch
28 Mode selector switch
32 LCD display
36 Cursor buttons
40 CCD
52 Motor drive
54 Motor drive
62 CPU
64 timer
70 Tripod sensor
72 Placement sensor

Claims (7)

An imaging device having a protection function for capturing a subject image through a lens and protecting the lens from impact caused by dropping,
Pressure detecting means for detecting the pressure applied when the photographer holds the pressure;
Based on the detection result by the pressure detection means, it is determined whether or not the imaging device is falling, and if it is determined to be falling, protection control means for controlling to operate the protection function;
An imaging device comprising: Based on the detection result by the pressure detection means, further has a setting means for setting a reference value used for drop determination for each photographer,
The imaging apparatus according to claim 1, wherein the protection control unit compares the detection result of the pressure detection unit with a reference value set by the setting unit to make a fall determination. The apparatus further comprises a selection unit for selecting one of a first mode in which the control of the protection control unit is executed and a second mode in which the control of the protection control unit is not executed. The imaging device according to claim 1 or 2. A fixing detection means for detecting that the position of the imaging device is fixed by a fixing member;
4. The control unit according to claim 1, wherein the protection control unit stops the control when the fixing of the position of the imaging apparatus is detected by the fixing detection unit. 5. The imaging device described in 1. After the protection function is operated by the protection control unit, an abnormality determination unit that executes a predetermined function test to determine whether there is an abnormality in the lens;
Informing means for informing the determination result by the abnormality determining means;
The imaging apparatus according to claim 1, further comprising: The imaging apparatus according to claim 5, further comprising a history storage unit that stores history information of determination by the abnormality determination unit. The lens is a retractable lens that can be expanded and contracted in the optical axis direction and can be accommodated in the main body of the imaging device by contraction of the lens barrel.
The imaging device according to claim 1, wherein the lens is housed in the main body by the protection function.

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