JP2009093013A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera capable of protecting automatically a front face of a photographing optical system member against damage and fouling. <P>SOLUTION: This camera for image-forming and photographing an optical image of a subject by the optical system member is provided with a detecting part for detecting an object existing along a subject direction from a front face part that is a surface in a subject side of the optical system member, a protection member having a shape covering the front face part of the optical system member, and movable between two positions of a protection position that is a position for covering the front face part with respect to the subject direction and an open position that is a position for exposing the front face part to the subject direction, and a control part for moving the protection member to the protection position, when detecting the object existing within a prescribed distance from the front face part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a camera that forms and shoots an optical image of a subject with an optical system member.

  In general, a lens cover that covers the front surface of the lens is attached to the front side of the lens other than during photographing in order to protect the front surface of the lens for photographing of the camera from damage and dirt such as scratches. Further, as disclosed in JP-A-10-282558, a camera having a lens cover (also referred to as a lens barrier) integrated with a camera body is also known.

In addition, it is also common to have a mechanism for moving a lens cover provided in the camera body, and to move the lens cover in accordance with switching of the power supply of the camera.
Japanese Patent Laid-Open No. 10-282558

  However, in conventional cameras, the lens cover is retracted from the field of view of the lens during the shooting operation, so that the lens is damaged or dirty due to the object touching the front surface of the lens during the shooting operation. It was impossible to prevent.

  For the purpose of protecting the lens, it is also common to mount a filter on the front surface of the lens for the purpose of protection. However, the protective filter is also an optical member that transmits the light beam from the subject. If there are scratches or dirt on the front surface of the filter, the scratches or dirt will be reflected. This will interfere with shooting.

  The present invention has been made in view of the above problems, and provides a camera capable of automatically protecting the front surface of a photographing optical system member that forms an optical image of a subject from being damaged or dirty. The purpose is to do.

  The camera according to the present invention is a camera that forms an optical image of a subject by using an optical system member and shoots an object present in the subject direction from a front surface portion of the optical system member on the subject side. A detecting portion for detecting, a shape that covers the front portion of the optical system member, a protection position that is a position that covers the front portion with respect to the subject direction, and the front portion is exposed with respect to the subject direction. When an object that is present within a predetermined distance from the front surface portion is detected by the protective member movably disposed between the two positions of the open position that is a position to be moved and the detection unit, the protection is performed. And a control unit that moves the member to the protection position.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In this embodiment described below, the present invention is applied to a camera generally called a digital still camera, a digital camera, an electronic camera, or the like.

  FIG. 1 is a perspective view showing the front side of the digital camera. FIG. 2 is a block diagram showing a main configuration of the digital camera.

  The digital camera 1 according to the present embodiment is a so-called waterproof digital camera in which an exterior member is configured to be watertight and has a configuration capable of operating in water. Here, the operation refers to a state in which the digital camera 1 can perform at least a shooting operation based on a shooting instruction from a user. That is, a predetermined function is limited in the water, and even a digital camera having a configuration in which, for example, a reproduction operation for displaying a captured image or a zoom operation for changing a shooting magnification cannot be performed can operate in the water. It shall be in the category of digital cameras.

  As shown in FIG. 1, an imaging unit 2, a flash light emitting device 4, a proximity sensor 14, and a lens protection mechanism 50 are disposed on the front surface of the digital camera 1 of the present embodiment. Here, the front surface refers to a surface on the side facing a subject to be imaged at the time of shooting.

  As will be described later in detail, the imaging unit 2 includes a lens unit that is an optical member for forming an optical image of a subject on an imaging element. In the present embodiment, the imaging lens 21 is disposed at a position closest to the subject of the lens unit. Note that another optical system member such as a filter or a prism may be disposed at a position closest to the subject of the lens unit.

  As shown in a partial cross section in FIG. 1, a lens protection mechanism 50 is disposed on the front surface of the digital camera 1. The lens protection mechanism 50 includes a lens protection member 51 and a lens protection member driving unit 53.

  The lens protection member 51 is disposed on the subject side of the imaging lens 21 so as to be able to advance and retract on the front surface (subject side surface) 21 a of the imaging lens 21. The lens protection member driving unit 53 is a mechanism unit that moves the lens protection member 51 forward and backward.

  More specifically, the lens protection member 51 is held in a metal frame-shaped holding portion 51b that is pivotally supported with respect to the casing of the digital camera 1, and in the frame of the holding portion 51b. And a protective filter 51a made of glass. The protective filter 51a is formed of a member that can transmit at least light in a visible light region with a predetermined transmittance. In addition, the protective filter 51a may be comprised with other materials, such as resin and a translucent ceramic.

  The lens protection member 51 is driven to be swingable around a rotation axis by a lens protection member driving unit 53 configured by a solenoid, a motor, or the like, and is positioned at two predetermined positions around the rotation axis.

  The position where the lens protection member 51 is positioned includes the protection position P where the protection filter 51a is disposed so as to cover the front surface 21a of the imaging lens 21, and the protection filter 51a and the holding portion 51b are retracted from the front surface 21a of the imaging lens 21. And two open positions O.

  Here, in the state in which the lens protection member 51 is positioned at the protection position P, the protection filter 51a is positioned on the subject side of the imaging lens 21, so that the digital camera 1 captures the subject through the protection filter 51a. To do. On the other hand, in a state where the lens protection member 51 is positioned at the open position O, the digital camera 1 captures the subject without passing through the protection filter 51a.

  In the present embodiment, the holding unit 51b is configured not to enter the field of view of the digital camera 1 even when the lens protection member 51 is positioned at either the protection position P or the open position O.

  The proximity sensor 14 serving as a detection unit is a device that detects an object that is close to a predetermined distance from the front surface 21a of the imaging lens 21 in a non-contact manner. In the present embodiment, the proximity sensor 14 includes a light source unit that irradiates spot light having a predetermined wavelength in the direction of the subject, and a distance measuring unit that includes a light position sensor (hereinafter referred to as PSD). Device.

  The proximity sensor 14 measures the distance from the object by the triangulation method from the position of the spot light irradiated from the light source unit, reflected by the object and incident on the PSD, and outputs it as distance data. Note that the distance measuring device using the PSD is a known technique, and thus detailed description thereof is omitted.

  In the present embodiment, the distance between the object present at the position corresponding to the central portion of the field of view of the digital camera 1 and the front surface 21a of the imaging lens 21 is measured by the proximity sensor 14 and output as distance data. Here, the digital camera 1 of the present embodiment includes an autofocus function (AF function) that automatically focuses on an object existing in the center of the field of view, and the center of the field of view is a so-called focus area. is there.

  That is, in this embodiment, the distance between the object focused by the AF function and the front surface 21a of the imaging lens 21 is measured by the proximity sensor 14 and output as distance data.

  The proximity sensor 14 may be another non-contact distance measuring device such as an ultrasonic sensor that measures a distance from an object by transmitting and receiving ultrasonic waves and measuring a time from transmission to reception. .

  In addition, an acceleration sensor 15 is provided in the housing of the digital camera 1 of the present embodiment. The acceleration sensor 15 is a device that measures the acceleration of the digital camera 1, and in this embodiment, a sensor that can measure accelerations in three axial directions orthogonal to each other is applied.

  On the top surface of the digital camera 1, there are provided a release switch 3 for performing a shooting instruction as an operation switch, and a power switch 5 for instructing a start-up operation and a shutdown operation of the digital camera 1.

  In addition, on the back (not shown) of the digital camera 1, the subject image is displayed as a moving image (live view display) at the time of shooting, the shot image is displayed, and shooting conditions and operation modes are changed. A liquid crystal display device 11 serving as a display unit for displaying the menu is provided.

  In addition, on the back surface of the digital camera 1, one or a plurality of switches, which are input devices for a user to instruct to change the shooting mode and parameter setting of the digital camera 1, are disposed.

  Hereinafter, one or a plurality of input devices arranged in the digital camera 1 for a user to input instructions to the digital camera 1 will be collectively referred to as an operation unit 12.

  The digital camera 1 according to the present embodiment performs macro mode for performing an operation suitable for close-up shooting, an underwater mode for performing an operation suitable for underwater shooting, and operations other than the macro mode and the underwater mode. Any one of the normal modes is selected as a photographing mode by the user via the operation unit 12.

  In addition to the switches described above, the operation unit 12 may include a wireless input device such as a remote controller, or an input device that inputs an instruction using a touch panel or a gesture using the acceleration sensor 15.

  Although not shown, the digital camera 1 has a side wall and a bottom that house a battery chamber that houses a primary battery or a secondary battery that is a power source, and a memory card 13 that is a recording medium for recording a captured image. A card storage room, a personal computer that is an external device, a USB (Universal Serial Bus) terminal that is a communication interface for performing wired or wireless communication with an external recording device, and the like are disposed.

A main configuration of the digital camera 1 having the above-described configuration is shown in FIG. 2 as a block diagram.
The imaging unit 2 includes a lens unit that is an optical system member including an imaging lens 21 and a focusing lens 22, a lens driving unit 23 that is an optical system driving unit, and an imaging device 20. The imaging unit 2 is appropriately provided with a zoom mechanism, a diaphragm device, an ND filter, a shutter device, a low-pass filter, a mirror, a prism, and the like.

  The focusing lens 22 is disposed so as to be able to advance and retract along the optical axis of the lens unit. The focusing distance of the lens unit is changed by moving the focusing lens 22 by a lens driving unit 23 having an actuator.

  The imaging device 20 includes a light receiving surface configured by arranging a plurality of pixel units, and photoelectrically converts an optical image of a subject formed on the light receiving surface by the imaging lens 21 and the focusing lens 22 into an electrical signal. Output as an image signal.

  The controller 30 serving as a control unit includes a plurality of circuit units such as an arithmetic device 31, an image processing device 40, a storage device 32, an AF controller 33, a lens protection mechanism controller 34, an input / output device, a power control device, and a timing circuit. And a control device that controls the operation of the digital camera 1.

  The plurality of circuit units constituting the controller 30 are electrically connected by a control line and a bus line, respectively. The arithmetic unit 31 controls the circuit unit according to the program code.

  The image processing device 40 is a circuit that generates image data by performing predetermined processing such as γ correction, color conversion, pixel conversion, and compression / decompression on the image signal output from the image sensor 20.

  The storage device 32 is a RAM that can be read and written at high speed, and is used as a temporary storage of image data and a work area of the controller 30. Although not shown, the controller 30 is also provided with a non-volatile memory that stores a setting value that is input by the user and that defines the operation of the digital camera 1.

  The AF controller 33 is a circuit that controls the operation of the lens driving unit 23 of the imaging unit 2 based on a command from the arithmetic device 31.

  In the digital camera 1 of the present embodiment, the image processing device 40 detects the contrast in the in-focus area, which is a predetermined area of the image acquired by the imaging unit 2, and the position of the focusing lens 22 at which the contrast is maximized. It is possible to perform a so-called contrast detection type auto-focus as a focus position.

  When focusing is performed by this contrast detection method, the AF controller 33 calculates a distance from the focused object (subject) and outputs the distance as a focusing distance.

  The lens protection mechanism controller 34 is a circuit that controls the operation of the lens protection member driving unit 53 of the lens protection mechanism 50 based on a command from the arithmetic device 31.

  The controller 30 configured as described above controls the overall operation of the digital camera 1 by reading and executing a program code recorded in a ROM (not shown).

  Further, the digital camera 1 is provided with the operation unit 12 including the above-described plurality of operation switches, a memory card 13, a proximity sensor 14, an acceleration sensor 15, and a display device drive circuit 16.

  The memory card 13 is a recording medium that includes a semiconductor nonvolatile memory, a small hard disk drive, and the like and is configured to be detachable from the digital camera 1.

  The display device driving circuit 16 is a circuit that drives the liquid crystal display device 11 and performs display based on the image data generated by the image processing device 40.

  The protection program executed by the controller 30 during the shooting operation of the digital camera 1 of the present embodiment having the above-described configuration will be described below with reference to FIGS. FIG. 3 is a flowchart of the protection program.

  First, in step S01, a setting value that defines the operation of the digital camera 1 is read. Here, the setting is an operation parameter defined by an item input in advance by the user via the operation unit 12 or a current switch state.

  The types of setting values read in step S01 are three items: “presence / absence of execution of protection program”, “current shooting mode”, and “user setting value”.

  Here, the setting value for whether or not the protection program is executed is a binary value that changes in accordance with the input of an instruction from the user, and enables or disables the lens protection operation executed by the protection program. Is defined. That is, the set value is a value that defines whether or not to invalidate the protection program.

  Also, the current setting value of the shooting mode is a value that changes in accordance with a shooting mode selection instruction from the user. In the present embodiment, the macro mode that performs an operation suitable for close-up shooting and underwater shooting are used. The underwater mode for executing a suitable operation and the normal mode for executing an operation other than the macro mode and the underwater mode are indicated by the value of the photographing mode.

  The set value of the user set value is a value of a lens protection distance (described later) input by the user, and is a numerical value of 0 or more. In this embodiment, the initial value of the lens protection distance before being changed by the user is set to zero.

  Next, in step S02, it is determined from the setting value read in step S01 whether or not the setting value indicating whether or not the protection program is executed invalidates the protection program. If the set value is a value that invalidates the protection program, the protection program is terminated. On the other hand, if the set value is a value that disables the protection program, the process proceeds to step S03.

  In step S03, the acceleration of the digital camera 1 is measured from the output of the acceleration sensor 15, and whether or not the recent change in acceleration per unit time (differential value of the change in acceleration) is equal to or greater than a predetermined value; It is determined whether or not the accelerations in the three axis directions of the digital camera 1 have all become approximately zero at the same time. In other words, in step S03, it is determined whether or not the acceleration of the digital camera 1 has changed abruptly and whether or not the digital camera 1 is in a free fall state.

  If it is determined in step S03 that the acceleration has suddenly changed or is in a free fall state, the process proceeds to step S04, where the lens protection member driving unit 53 is controlled to move the lens protection member 51 to the protection position P. Let Thereby, the front surface 21a of the imaging lens 21 can be protected from impact.

  If it is determined in step S03 that the acceleration has changed suddenly or is in a free fall state, if the camera has a retractable lens unit, the lens unit is controlled to be in a retracted state, that is, in a contracted state. In the case where the zoom lens unit is provided, the control for moving the zoom position to the position where the strength against impact is the highest may be performed at the same time.

  In step S05, distance data indicating the distance between the front surface 21a of the imaging lens 21 and the nearest object existing in front of the front surface 21a of the imaging lens 21 that is output from the proximity sensor 14 is acquired.

  Next, in step S06, the current in-focus distance output from the AF controller 33 is acquired. The in-focus distance is data indicating the distance between the front surface 21a of the imaging lens 21 and the currently focused object.

  Next, in step S07, a lens protection distance calculation process, which will be described in detail later, is executed to calculate a lens protection distance used for determining whether or not to move the lens protection member 51 to the protection position P.

  Next, in step S08, the lens protection distance calculated in step S07 is compared with the distance data acquired in step S05, and it is determined whether the distance indicated by the distance data is equal to or less than the lens protection distance.

  If it is determined in step S08 that the distance data is greater than the lens protection distance, the process proceeds to step S12. In step S12, the lens protection member drive unit 53 is controlled to move the lens protection member 51 to the open position O.

  Next, in step S13, a protection timer that is a variable stored in the storage device 32 is initialized, and the value of the protection timer is set to zero.

  In step S14, it is determined whether or not the setting value read in step S01 has been changed. If it is determined that the setting value has been changed, the process returns to step S01, and the above processing is repeated from the setting value acquisition processing. If it is determined that the set value has not been changed, the process returns to step S03 and the above process is repeated.

  On the other hand, if it is determined in step S08 that the distance data is equal to or smaller than the lens protection distance, the process proceeds to step S09. In step S09, the lens protection member driving unit 53 is controlled to move the lens protection member 51 to the protection position P.

  In step S09, the lens protection member 51 is moved to the protection position P, and a display for notifying the user that the lens protection member 51 is currently in the protection position P is displayed on the liquid crystal display device 11 or an LED or the like. Also good.

  Next, in step S10, a protection timer, which is a variable stored in the storage device 32, is added by a predetermined value. In other words, the protection timer is a variable indicating the duration of time that the lens protection member 51 is located at the protection position P.

  Next, in step S11, it is determined whether or not the value of the protection timer is greater than or equal to a predetermined value. When it is determined that the value of the protection timer is equal to or greater than the predetermined value, the operation termination process of the digital camera 1 is executed, and the digital camera 1 is turned off. If it is determined that the value of the protection timer is smaller than the predetermined value, the process proceeds to step S14 and the above-described processing is executed.

  Next, the lens protection distance calculation process executed in step S07 described above will be described with reference to the flowchart shown in FIG.

  First, in step S21, it is determined whether or not a user setting value for the lens protection distance is input from the setting value acquired in step S01 described above. In the present embodiment, if the user setting value is a value other than 0, it is determined that the user setting value of the lens protection distance has been input, the process proceeds to step S25, and the user setting value is stored in the storage device 32 as the lens protection distance. The lens protection distance calculation process is completed.

  On the other hand, if the user setting value is 0, it is determined that the user setting value of the lens protection distance has not been input, and the process proceeds to step S22.

  In step S22, it is determined from the setting value acquired in step S01 described above whether or not the current shooting mode is the macro mode. If it is determined that the current shooting mode is the macro mode, the process proceeds to step S26, and the lens protection distance Dm for the macro mode is calculated using an expression described later based on the current focus distance and the like. Then, the lens protection distance Dm for the macro mode is stored in the storage device 32 as a lens protection distance, and the lens protection distance calculation process is terminated.

  On the other hand, if it is determined in step S22 that the current shooting mode is not the macro mode, the process proceeds to step S23.

  In step S23, it is determined from the setting value acquired in step S01 described above whether or not the current shooting mode is the underwater mode. When it is determined that the current shooting mode is the underwater mode, the process proceeds to step S27, and the lens protection distance Dw for the underwater mode is calculated using an expression described later. Then, the lens protection distance Dw for the underwater mode is stored in the storage device 32 as a lens protection distance, and the lens protection distance calculation process is terminated.

  On the other hand, if it is determined in step S23 that the current shooting mode is not the underwater mode, the process proceeds to step S24.

  In step S24, the lens protection distance Dn for the normal mode is calculated using an expression described later based on the current in-focus distance and the like. Then, the lens protection distance Dn for the normal mode is stored in the storage device 32 as a lens protection distance, and the lens protection distance calculation process is terminated.

  Here, the lens protection distance Dm for the macro mode, the lens protection distance Dw for the underwater mode, and the lens for the normal mode, which are respectively calculated in step S25, step S26, and step S24 of the lens protection distance calculation process of the present embodiment. A method of calculating the protection distance Dn will be described with reference to the table of FIG.

First, when the shooting mode is neither the macro mode nor the underwater mode, that is, when the shooting mode is the normal mode and the current focusing distance is less than 5 meters, the lens for the normal mode is expressed by the following equation (1). The protection distance Dn is calculated.
Dn = 0.2 × (Y / 5) +0.1 Formula (1)
Here, Dn represents the lens protection distance [m] for the normal mode, Y represents the current focusing distance [m], and 0 ≦ Y <5.

  That is, in the normal mode and when the focus distance is relatively close to less than 5 meters, the value of the lens protection distance changes in proportion to the focus distance. Specifically, the lens protection distance varies between 0.1 meter and 0.3 meter depending on the focusing distance.

When the shooting mode is the normal mode and the current focus distance is 5 meters or more, the lens protection distance Dn for the normal mode is calculated by the following equation (2).
Dn = 0.3 Formula (2)
That is, in the normal mode, when the current focusing distance is 5 meters or more which is relatively far, the value of the lens protection distance is fixed to a constant value of 0.3 meters.

When the shooting mode is the macro mode, the lens protection distance Dm for the macro mode is calculated by the following equation (3).
Dm = 0.5 × Dn Formula (3)
In the macro mode, the value of the lens protection distance is a value obtained by multiplying the lens protection distance Dn for the normal mode by a value smaller than 1. That is, the value of the lens protection distance is set to a value smaller than the lens protection distance Dn for the normal mode.

When the shooting mode is the underwater mode, the lens protection distance Dw for the underwater mode is calculated by the following equation (4).
Dw = ∞ Formula (4)
That is, in the underwater mode, the value of the lens protection distance is infinite.

  In the digital camera 1 of the present embodiment described above, the distance between the lens protection member 51 disposed so as to be able to advance and retract on the front surface 21a side of the imaging lens 21 of the lens unit and the object existing on the front surface 21a side of the imaging lens 21 is determined. When the distance detected by the proximity sensor 14 is equal to or less than a lens protection distance that is a predetermined value, the lens protection member 51 is placed in a protected position on the front surface 21a of the photographing lens 21. It is configured to move to P.

  That is, the digital camera 1 according to the present embodiment covers the front surface 21 a of the imaging lens 21 with the lens protection member 51 and covers the front surface 21 a when the object is within the lens protection distance from the front surface 21 a of the imaging lens 21. It has the structure which protects from contact with.

  With this configuration, according to the present embodiment, it is possible to prevent the user from unintentionally touching the front surface 21a of the imaging lens 21 and the subject or an obstacle from coming into contact with the front surface 21a of the imaging lens 21. Further, it is possible to prevent the front surface 21a of the image pickup lens 21 from being contaminated or causing damage such as scratches.

  Further, as described above, the digital camera 1 of the present embodiment has a configuration in which the acceleration sensor 15 detects an impact or a drop applied to the digital camera 1 and protects the front surface 21 a of the imaging lens 21 with the lens protection member 51. Have. For this reason, it is possible to prevent damage to the imaging lens 21 more reliably.

  Further, at least a region of the lens protection member 51 that overlaps the visual field of the digital camera 1 is made of a material that transmits visible light. Therefore, the digital camera 1 of the present embodiment can perform shooting and live view display (finder display) even when the lens protection member 51 is moved to the protection position P.

  With this configuration, according to the present embodiment, it is possible to perform framing and shooting by live view even when the imaging lens 21 is protected by the lens protection member 51.

  For example, even when the user suddenly brings a subject or a finger close to the imaging lens 21 during the shooting operation and the lens protection member 51 moves to the protection position P, the user can continue the shooting operation without being hindered. Can be done.

  Therefore, the user can concentrate on shooting comfortably without missing a shooting opportunity (shutter chance) or being confused by the shooting rhythm, in other words, without being aware of the presence of the lens protection mechanism 50. .

  In addition, the digital camera 1 according to the present embodiment has a configuration in which the power is turned off when the lens protection member 51 is located at the protection position P for a predetermined time or more as shown in the determination in step S11.

  When the lens protection member 51 is located at the protection position P for a predetermined time or more, that is, when an object is present for a long time in the vicinity of the imaging lens 21, for example, the power is turned on due to unexpected contact in a bag or case. A case is assumed. Even in such a case, since the digital camera 1 is automatically turned off, it is possible to protect the imaging lens 21 and to prevent wasteful power consumption.

  Further, the digital camera 1 of the present embodiment has a configuration in which the lens protection distance used for the determination of moving the lens protection member 51 to the protection position P is changed in proportion to the in-focus distance detected by the autofocus function. That is, the closer the subject is to the imaging lens 21, the shorter the lens protection distance.

  With this configuration, according to the present embodiment, when the subject approaches the front surface 21a of the imaging lens 21, close-up shooting (macro shooting) causes the lens protection member 51 to be frequently at the protection position P by shortening the lens protection distance. It can be prevented from moving. Therefore, it is possible to suppress the generation of vibration and sound due to unnecessary movement of the lens protection member 51 and to reduce power consumption.

  In this embodiment, the lens protection distance changes according to the selected shooting mode. Specifically, when the macro mode used during close-up shooting is selected, the lens protection distance is shorter than in the normal shooting mode. Thereby, it is possible to prevent the lens protection member 51 from frequently moving to the protection position P, to suppress generation of vibration and sound due to unnecessary movement of the lens protection member 51, and to reduce power consumption. .

  In the macro mode, the lens protection distance may be fixed to a predetermined value. In this case, it is preferable that the lens unit is fixed to the shortest possible shooting distance or a value shorter than the shortest possible shooting distance.

  When the underwater mode is selected, the lens protection distance is infinite. That is, the lens protection member 51 is always positioned at the protection position P when the underwater mode is selected. This is because, underwater, accurate distance measurement by the proximity sensor 14 including an infrared sensor using PSD or an ultrasonic sensor using ultrasonic waves is impossible.

  With this configuration, power consumption can be suppressed by stopping the driving of the proximity sensor 14 in the underwater mode, and the continuous operation time of the digital camera 1 can be extended.

  Needless to say, the same effect can be obtained even when the lens protection distance is set to 0 in the underwater mode and the lens protection member 51 is always positioned at the open position O. Further, even in the case of a digital camera that does not have a waterproof structure in the housing as in the present embodiment but performs photographing in water in a state of being accommodated in a waterproof case, the proximity sensor 14 is similarly accurate in water. Since ranging is impossible, this configuration can be applied in the same manner.

  In the present embodiment described above, the underwater mode is selected by the operation of the operation unit 12 by the user. For example, the digital camera 1 includes a submergence detection sensor and a pressure sensor, and digital signals are output from these outputs. It may be configured to automatically determine whether the camera 1 is underwater and automatically switch to the underwater mode.

  Further, it goes without saying that the present invention is applicable to a digital camera that does not have an underwater mode, that is, cannot be photographed underwater.

  In the present embodiment, the lens protection member 51 of the lens protection mechanism 50 is rotated about a predetermined axis by the lens protection member driving unit 53 and moves between the protection position P and the open position O. However, for example, as illustrated in FIG. 6, the lens protection member 51 may be configured to move between the protection position P and the open position O in a substantially linear shape.

  For example, as shown in FIG. 7, the lens protection member 51 of the lens protection mechanism 50 is rotated around an axis that is substantially perpendicular to the principal ray incident on the imaging lens 21, so that the protection position P and The form which moves between the open positions O may be sufficient.

(Second Embodiment)
Below, the 2nd Embodiment of this invention is described with reference to FIG. This embodiment is mainly different from the first embodiment in the method of calculating the lens protection distance. Therefore, only this difference will be described below.

  The digital camera 1 according to this embodiment includes a zoom lens or a varifocal lens having a variable focal length as a lens unit of the imaging unit 2. In this embodiment, in the lens protection distance calculation process, the lens protection distance is calculated based on the formula shown in the table of FIG.

First, when the shooting mode is the normal mode, the lens protection distance Dn for the normal mode is calculated by the following equation (5).
Dn = 0.2 × (x / Xmax) +0.1 Expression (5)
Here, Dn is the lens protection distance [m] for the normal mode, x is the focal length of the current lens unit, and Xmax is the maximum focal length of the lens unit.

  That is, in the normal mode, the value of the lens protection distance changes in proportion to the focal length of the lens unit. Specifically, the lens protection distance changes with a value of 0.3 meters or less according to the focal length of the lens unit.

When the shooting mode is the macro mode, the lens protection distance Dm for the macro mode is calculated by the following equation (6).
Dm = Ymin (6)
Here, Ymin is the shortest possible photographing distance at the current focal length of the lens unit.

When the shooting mode is the underwater mode, the lens protection distance Dw for the underwater mode is calculated by the following equation (4) as in the first embodiment.
Dw = ∞ Formula (4)
The digital camera 1 according to the present embodiment described above includes a zoom lens, and changes the lens protection distance for moving the lens protection member 51 to the protection position P in proportion to the focal length of the zoom lens. That is, the lens protection distance becomes shorter as the lens unit is on the wide angle side.

  If the zoom position of the lens unit is at the telephoto side, the shortest possible shooting distance is considered to be long and the subject is relatively far away, but if the zoom position is at the wide-angle side, the shortest possible shooting distance is short. This is because the lens unit may exist in the vicinity.

  With this configuration, at the time of wide-angle shooting where the subject approaches the lens unit, the lens protection member 51 can be prevented from frequently moving to the protection position P by shortening the lens protection distance. Therefore, it is possible to suppress the generation of vibration and sound due to unnecessary movement of the lens protection member 51 and to reduce power consumption.

(Third embodiment)
Below, the 2nd Embodiment of this invention is described with reference to FIG.9 and FIG.10. This embodiment is mainly different from the first embodiment in the autofocus format and the lens protection distance calculation method. Therefore, only this difference will be described below.

  The digital camera of the present embodiment includes a so-called TTL (Through The Lens) phase difference type autofocus mechanism.

  As shown in FIG. 9, the TTL phase difference type autofocus mechanism forms two images by using a separator lens from a part of the light beam that has passed through the lens unit, and sets the interval between the two images. This is a well-known technique in which it is measured from the output of the line sensor to detect the front pin or the rear pin and the defocus amount, and the focus lens is driven to the in-focus position.

  In the present embodiment, as shown in FIG. 10, when the light incident on the line sensor from the separator lens has a peak on the near side of the protection distance, which is a predetermined distance, that is, on the lens unit side, the lens The protection member 51 is configured to move to the protection position P.

  That is, in the present embodiment, the lens protection member 51 is moved to the protection position P when it is detected that an object is present on the front pin side of the protection distance in the AF distance measurement area for performing the TTL phase difference type autofocus. The front surface 21a of the imaging lens 21 is protected.

  According to such a configuration, the same effect as that of the first embodiment can be obtained, and the distance measuring device used for autofocus can be used for detecting an object close to the front surface 21a of the imaging lens 21. Therefore, the configuration of the digital camera 1 can be simplified.

  In the case of the digital camera 1 having a plurality of AF ranging areas for performing TTL phase difference type autofocusing, as shown in FIG. 10, it is detected that an object exists on the front pin side of the protection distance. Only when the distance area is a predetermined number or more, the lens protection member 51 may be moved to the protection position P to protect the front surface 21a of the imaging lens 21.

  According to such a configuration, it is possible to reduce false detection compared to a case where an object is detected by one AF ranging area.

  In this embodiment, the TTL phase difference type autofocus mechanism is used to detect an object close to the front surface 21a of the imaging lens 21. For example, as in the digital camera 1 of the first embodiment, a PSD is used. In the case of a digital camera equipped with the distance measuring device used, the distance measuring device may be used in combination with so-called infrared active autofocus distance measurement.

Based on the embodiment described above, the following configuration can be proposed. That is,
(Appendix 1)
A camera for converting a subject image formed through a lens into a digital image,
A lens protection shutter mechanism disposed in front of the lens;
Detecting means for detecting an object close to the lens;
Control means for controlling the lens protection shutter mechanism to close when the detection means detects an object within a predetermined distance from the lens;
A camera characterized by comprising:

(Appendix 2)
The detection means is an ultrasonic sensor that detects a distance to an object by measuring a reflection time of an ultrasonic wave transmitted from an ultrasonic transmission source disposed in the camera, or a light from a light source disposed in the camera. The camera according to appendix 1, wherein the camera is an optical sensor that measures the direction of the reflected light to detect the distance to the object.
(Appendix 3)
The camera according to appendix 1, wherein the detection means is a sensor that detects defocus for the autofocus mechanism of the camera.

(Appendix 4)
The camera according to any one of appendices 1 to 3, wherein the control means includes protection distance determination means for determining a distance for closing the protection shutter.

(Appendix 5)
The protection distance determination unit closes the lens protection shutter according to at least one of a shooting mode for setting a relationship between shooting parameters of the camera, a current focus distance of the lens, and a shortest shooting distance. The camera according to appendix 4, wherein a distance is determined.

(Appendix 6)
It further has a time measuring means for measuring time,
The camera according to appendix 1, wherein the camera is turned off when the protective shutter is closed for a predetermined time or longer.

(Appendix 7)
The camera according to any one of appendices 1 to 6, wherein the protective shutter is formed of a member that transmits at least visible light.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope or spirit of the invention that can be read from the claims and the entire specification. Is also included in the technical scope of the present invention.

  The camera according to the present invention is not limited to the form of the digital camera described in the above-described embodiment, and may be a form of photographing with a film, or a recording device, a mobile phone, and a PDA provided with an image pickup unit that performs photographing. Other electronic devices such as a game machine, a digital video camera, a digital media player, a television, a GPS, and a clock may be used.

It is a perspective view which shows the front side of a digital camera. It is a block diagram which shows the main structures of a digital camera. It is a flowchart of a protection program. It is a flowchart of a lens protection distance calculation process. It is a table | surface which shows the calculation method of a lens protection distance for every condition. It is a perspective view which shows the modification of 1st Embodiment. It is a perspective view which shows the modification of 1st Embodiment. It is a table | surface which shows the calculation method of the lens protection distance in 2nd Embodiment for every condition. It is a figure which shows the outline | summary of the autofocus of a TTL phase difference system. It is a figure for demonstrating the method of the object detection in 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Digital camera, 2 Imaging part, 11 Liquid crystal display device, 12 Operation part, 13 Memory card, 14 Proximity sensor, 15 Acceleration sensor, 16 Display apparatus drive circuit, 20 Imaging element, 21 Imaging lens, 21a Front surface, 22 Focusing lens, 23 lens drive unit, 30 controller, 31 arithmetic unit, 32 storage device, 33 AF controller, 34 lens protection mechanism controller, 51 lens protection member, 53 lens protection member drive unit, O open position, P protection position

Claims (7)

A camera that forms and shoots an optical image of a subject by an optical member;
A detection unit that detects an object present in the subject direction from a front surface portion that is a surface of the optical system member on the subject side;
The optical system member has a shape that covers the front portion, and a protective position that is a position that covers the front portion with respect to the subject direction, and an open position that is a position where the front portion is exposed with respect to the subject direction. And a protective member arranged to be movable between the two positions,
A control unit that moves the protection member to the protection position when an object that is present within a predetermined distance from the front surface is detected by the detection unit;
A camera comprising:   The camera according to claim 1, wherein the control unit includes a protection distance calculation unit that calculates the predetermined distance for moving the protection member to the protection position.   The protection distance calculation unit includes a shooting mode that defines an operation at the time of shooting of the camera, a focusing distance of the optical system member, a focal length of the optical system member, and a shortest possible shooting distance of the optical system member. The camera according to claim 2, wherein the predetermined distance is calculated based on at least one of the following information. It also has a timekeeping part that keeps time,
The camera according to any one of claims 1 to 3, wherein when the state in which the protection member is located at the protection position continues for a predetermined time or more, the power of the camera is turned off.   The camera according to any one of claims 1 to 4, wherein at least a part of the protective member is formed of a member that transmits visible light at a predetermined transmittance.   The detection unit measures the reflection time of the ultrasonic wave transmitted from the ultrasonic transmission source and detects the distance to the object, or measures the direction of the reflected light of the light emitted from the light source. The camera according to claim 1, wherein the camera is an optical sensor that detects the distance to the camera.   The camera according to claim 1, wherein the detection unit is a sensor that detects defocus for an autofocus mechanism of the camera.

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