JP3843001B2 - Interchangeable lens SLR digital camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an interchangeable lens single-lens reflex digital camera, and particularly to protection of an image sensor provided in a camera body.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a lens interchangeable single-lens reflex digital camera having a valve mechanism is known. In such a digital camera, it is usually possible to use the valve mechanism even when the interchangeable lens is detached from the camera body, that is, the shutter can be kept open for a long time.
[0003]
[Problems to be solved by the invention]
However, if the shutter is opened carelessly for a long time with the interchangeable lens removed from the camera body, dust may adhere to the light receiving surface side of the image sensor. When shooting is performed in a state where dust is attached to the light receiving surface side of the image sensor, shadows of dust are mixed into the obtained subject image.
[0004]
An object of the present invention is to prevent a shutter from being kept open for a long time in a state where an interchangeable lens is detached from the camera in an interchangeable lens single-lens reflex digital camera, and to avoid the possibility of dust adhering to an image sensor. Yes.
[0005]
[Means for Solving the Problems]
The interchangeable lens single-lens reflex digital camera according to the present invention has an interchangeable lens that is detachable, a camera body provided with a shutter, and an interchangeable lens detection unit that detects whether the interchangeable lens is attached to the camera body. And a shutter control means for restricting the opening / closing operation of the shutter in a state in which the interchangeable lens detecting means detects that the interchangeable lens is released from the camera body.
[0006]
The shutter control means preferably opens the shutter when a shutter opening permission signal is output. The shutter opening permission signal is output, for example, by setting a cleaning mode for forcibly opening the shutter for cleaning the inside of the camera body. By configuring so that the shutter does not open unless the shutter opening permission signal is output, it is possible to reliably prevent dust from adhering to the image sensor.
[0007]
The shutter control means may limit the opening time of the shutter within a certain time. For example, even when the shutter is opened for a long time for cleaning the inside of the camera body, dust can be prevented from adhering to the image sensor by forcibly closing the shutter.
[0008]
The shutter control means may be capable of prohibiting a shutter opening operation at a shutter speed longer than a predetermined time. Even in such a configuration, as described above, it is preferable that the shutter control unit opens the shutter when the shutter opening permission signal is output. The shutter control means may limit the opening time of the shutter within a certain time.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a digital camera to which the first embodiment of the present invention is applied as viewed from the rear.
[0010]
This digital camera is a single-lens reflex camera, and the interchangeable lens 11 is detachably attached to the camera body 90. An optical finder 91 is provided at the center of the upper portion of the camera body 90, and a liquid crystal panel (LCD) 46 for image display is provided at the approximate center of the back surface 92. On the liquid crystal panel 46, an image obtained by the interchangeable lens 11 is displayed as a moving image, and a still image recorded on a recording medium (not shown) such as a PC card by a photographing operation can be displayed. A mode setting switch 95 is provided beside the liquid crystal panel 46. The mode setting switch 95 is provided for setting various operation modes, and is a jog dial in the illustrated embodiment.
[0011]
When the camera body 90 is viewed from the back, a shutter button 93 and a status display device 56 are provided on the right side of the upper part of the camera body 90. The status display device 56 is composed of a liquid crystal display element, and various setting states of the digital camera are displayed as characters or symbols on the liquid crystal display element. When the shutter button 93 is half-pressed, photometry, distance measurement, etc. are performed, and when it is fully pressed, a still image is recorded on the PC card.
[0012]
A card slot 96 is formed on the side surface of the camera body 90. The card slot 96 is provided for inserting a PC card into the camera body 90, and a card connector (not shown) into which the PC card is inserted is provided inside the card slot 96.
[0013]
FIG. 2 is a block diagram mainly showing an electrical configuration of the digital camera. The operation of this camera is controlled by a system controller 31 having a microcomputer. That is, under the control of the system controller 31, a moving image or a still image is displayed on the liquid crystal panel 46, and the still image is recorded on the PC card.
[0014]
The interchangeable lens 11 is electrically connected to an electric circuit provided in the camera body 90 (FIG. 1) via mount pins 12, 13, and 14. In the lens barrel of the interchangeable lens 11, a front group lens 15 and a rear group lens 16 that are photographing optical systems are provided, and a diaphragm 17 is provided between these lenses 15 and 16. Focus adjustment for each of the lenses 15 and 16 is performed by a lens control circuit 18, and a zooming operation is performed by a zoom motor 19. The lens control circuit 18 and the zoom motor 19 operate according to control signals sent from the system controller 31 provided in the camera body via the mount pins 13 and 14. The diaphragm 17 operates in accordance with a control signal sent from the diaphragm drive circuit 32 provided in the camera body via the mount pin 12, and the opening degree of the diaphragm 17 is adjusted. The aperture drive circuit 32 is controlled by the system controller 31.
[0015]
The mount pins 12, 13, and 14 are supported by an annular mount plate 80 provided in an opening (not shown) of the camera body, and, as is conventionally known, from the hole formed in the mount plate 80 to the interchangeable lens 11 side. Protruding. The mount plate 80 is provided with an interchangeable lens mounting detection switch 81 in the same form as the mount pins 12, 13, and 14. The mount plate 80 and the interchangeable lens mounting detection switch 81 are connected to the system controller 31, the mount plate 80 is grounded, and a voltage of a predetermined magnitude is applied to the interchangeable lens mounting detection switch 81.
[0016]
Therefore, when the interchangeable lens 11 is attached to the camera body 90, the end of the interchangeable lens 11 contacts not only the mount pins 12, 13, and 14 but also the interchangeable lens mounting detection switch 81 and the mount plate 80. As a result, the interchangeable lens mounting detection switch 81 and the mount plate 80 are electrically connected to each other so that the interchangeable lens mounting detection switch 81 is turned on, and the system controller 31 indicates that the interchangeable lens 11 is mounted on the camera body 90. An interchangeable lens detection signal is input.
[0017]
A quick return mirror 21 is provided on the optical axes of the lenses 15 and 16 in the camera body. The quick return mirror 21 is rotatable between the illustrated inclined state and the horizontal state rotated upward. A focus plate 22 is provided above the quick return mirror 21, and a pentaprism 23 is provided above the focus plate 22. An eyepiece 24 of a finder 91 (FIG. 1) is disposed behind the pentaprism 23.
[0018]
A shutter 25 is provided behind the quick return mirror 21, and an infrared cut filter 26 and an optical low-pass filter 27 are provided behind the shutter 25. A CCD (imaging device) 33 is provided behind the optical low-pass filter 27. That is, the quick return mirror 21, the shutter 25, the infrared cut filter 26, the optical low-pass filter 27, and the CCD 33 are disposed on the optical axes of the lenses 15 and 16.
[0019]
The rotation operation of the quick return mirror 21 is driven by a mirror drive circuit 34, and the opening / closing operation of the shutter 25 is driven by a shutter drive circuit 35. The mirror drive circuit 34 and the shutter drive circuit 35 are controlled by the system controller 31.
[0020]
Usually, the mirror 21 is set in an inclined state, and guides light taken from the interchangeable lens 11 to the pentaprism 23 side. At this time, the shutter 25 is closed, and the optical path toward the CCD 33 is closed. On the other hand, when photographing is performed, the mirror 21 is rotated upward by the control of the mirror driving circuit 34 and becomes horizontal. As the mirror 21 rotates, the shutter 25 is opened under the control of the shutter drive circuit 35, and the light taken from the interchangeable lens 11 is applied to the light receiving surface of the CCD 33. That is, an image obtained by the lenses 15 and 16 is formed on the light receiving surface, and the CCD 33 generates an imaging signal corresponding to the image.
[0021]
A pulse signal generation circuit (PPG) 36 is connected to the system controller 31, and the pulse signal generation circuit 36 generates various pulse signals under the control of the system controller 31. Based on these pulse signals, the CCD drive circuit 37, the A / D converter 38, and the image signal processing circuit 39 are driven, and the CCD drive circuit 37 controls the operation of the CCD 33. That is, the image pickup signal read from the CCD 33 is converted into a digital signal by the A / D converter 38 and subjected to predetermined image processing in the image signal processing circuit 39. An image buffer memory 40 having a sufficient capacity for storing digital image data corresponding to one image is connected to the image signal processing circuit 39.
[0022]
A monitor interface 41 and a card interface 42 are connected to the image signal processing circuit 39. These interfaces 41 and 42 are controlled by the system controller 31.
[0023]
A backlight 45 and a liquid crystal panel 46 are connected to the monitor interface 41 via a liquid crystal drive circuit 44. In the liquid crystal panel 46, as described above, the liquid crystal driving circuit 44 is controlled based on the image data read from the image buffer memory 40, and a still image is displayed. A card connector 47 is connected to the card interface 42, and a PC card 43 can be attached to the card connector 47.
[0024]
An AF sensor 51, a photometric sensor 52, and an auto white balance sensor 53 are connected to the system controller 31. The AF sensor 51 has a conventionally known configuration, and the AF sensor 51 measures the focus adjustment state of the lenses 15 and 16. The photometric sensor 52 performs photometry to determine the opening of the diaphragm 16 at the time of exposure and the charge accumulation time (exposure time) in the CCD 33. The auto white balance sensor 53 measures the color temperature of the ambient light.
[0025]
The system controller 31 is connected to a photometric switch 54, a release switch 55, and a status display device 56. The metering switch 54 is turned on by half-pressing the shutter button 93, whereby the metering sensor 52 performs metering. The release switch 55 is turned on when the shutter button 93 is fully pressed, whereby the shutter 25 is driven to open and close. That is, the CCD 33 is exposed, and an imaging signal corresponding to the image is generated on the CCD 33.
[0026]
Further, a buzzer 57 and a mode setting switch 95 are connected to the system controller 31. As will be described later, the buzzer 57 generates a warning sound when the shutter 25 is opened for a predetermined time or longer with the interchangeable lens 11 released from the camera body 90. The mode setting switch 95 is a jog dial as described above, and the mode is set by determining and pressing the rotation position according to various modes.
[0027]
FIG. 3 is a flowchart of a shutter release operation control routine. This control routine is executed by the system controller 31.
[0028]
Step 101 is repeatedly executed until the release switch 55 is set to the on state. When the release switch 55 is set to the on state by the user pressing the shutter button 93, it is determined in step 102 whether or not the interchangeable lens mounting detection switch 81 is set to the on state, that is, the interchangeable lens 11 is mounted on the camera body 90. It is determined whether or not. When the interchangeable lens 11 is attached, normal shooting is executed in step 103, and this routine ends.
[0029]
When it is determined in step 102 that the interchangeable lens mounting detection switch 81 is in the off state, that is, it is determined that the interchangeable lens 11 is not mounted, it is determined in step 104 whether or not the cleaning mode is set. The cleaning mode is a mode in which the shutter 25 is forcibly opened to clean the inside of the camera body 90 (for example, the light receiving surface of the CCD 33), and is set by operating the mode setting switch 95. By setting the cleaning mode, a shutter opening permission signal is output from the mode setting switch 95, whereby step 111 and subsequent steps are executed.
[0030]
In step 111, the quick return mirror 21 is rotated upward to be set in a horizontal state. In step 112, the shutter 25 is opened. In step 113, it is determined whether or not the release switch 55 has been switched to the off state. When the user releases the shutter button 93 and the release switch 55 is switched to the OFF state, the process proceeds to step 116 where the shutter 55 is closed. In step 117, the quick return mirror 21 is rotated downward to return to the inclined state, and this routine ends.
[0031]
That is, the user can open the shutter 25 by pressing the shutter button 93 and clean the light receiving surface of the CCD 33 while maintaining this state. When a time limit (for example, 30 seconds) elapses during this work, the buzzer 57 generates a warning sound and the shutter 25 closes. That is, when it is determined in step 113 that the release switch 55 is not in the OFF state, it is determined in step 114 whether or not the time limit has elapsed since the shutter 25 was opened. However, when the time limit has elapsed, the buzzer 57 is activated in step 115 and a warning sound is generated for a predetermined time (for example, 3 seconds). Steps 116 and 117 are then executed, and this routine ends.
[0032]
As described above, in the shutter release operation control routine, in a state where it is detected that the interchangeable lens 11 is released from the camera body 90, the opening / closing operation of the shutter 25 is limited, and the opening time of the shutter 25 is limited to a certain value or less. Is done. Therefore, for example, a situation where the shutter 25 is inadvertently opened for a long time with the interchangeable lens 11 removed is avoided, and dust is prevented from adhering to the CCD 33. Further, in this embodiment, since the shutter 25 can be opened only in the cleaning mode, it is possible to more reliably prevent dust from adhering to the CCD 33.
[0033]
FIG. 4 is a flowchart of a shutter release operation control routine in the second embodiment. The second embodiment has the same configuration as the first embodiment except for the shutter release operation control routine.
[0034]
Steps 201 to 203 are the same as steps 101 to 103 (FIG. 3). In step 204, it is determined whether or not the cleaning mode is set. When it is determined that the cleaning mode is not set, in step 205, the shutter speed is set to a low speed of a predetermined time (for example, 1 second) or more. It is determined whether or not there is. If the shutter speed is not equal to or greater than the predetermined time, step 203 is executed. That is, a normal shooting operation is performed and shutter release is performed. On the other hand, when the shutter speed is equal to or longer than the predetermined time, if the shutter 25 is opened, dust may adhere to the CCD 33, so the process returns to step 201 and the shutter 25 is not opened.
[0035]
When it is determined in step 204 that the cleaning mode is set, the process proceeds to step 211. Steps 211 to 217 are the same as steps 111 to 217 (FIG. 3).
[0036]
As described above, in the second embodiment, when not in the cleaning mode, the shutter opening operation with a shutter speed longer than the predetermined time is prohibited, and when the shutter speed is relatively fast, the shutter release is permitted.
[0037]
【The invention's effect】
As described above, according to the present invention, in the interchangeable lens single-lens reflex digital camera, it is possible to prevent the shutter from being kept open for a long time with the interchangeable lens removed from the camera, and there is a risk that dust may adhere to the image sensor. Avoided.
[Brief description of the drawings]
FIG. 1 is a perspective view of a digital camera according to a first embodiment of the present invention as viewed from the rear.
FIG. 2 is a block diagram mainly showing an electrical configuration of the digital camera.
FIG. 3 is a flowchart of a shutter release operation control routine in the first embodiment.
FIG. 4 is a flowchart of a shutter release operation control routine in a second embodiment.
[Explanation of symbols]
55 Release switch 57 Buzzer

Claims (8)

An interchangeable lens is detachable, and a camera body provided with a shutter;
Interchangeable lens detection means for detecting whether or not the interchangeable lens is attached to the camera body;
A lens-interchangeable single-lens reflex digital camera, comprising: shutter control means for restricting an opening / closing operation of the shutter in a state where the interchangeable lens detection means detects that the interchangeable lens is released from the camera body. camera. 2. The interchangeable-lens single-lens reflex digital camera according to claim 1, wherein the shutter control means opens the shutter when a shutter opening permission signal is output. The interchangeable-lens single-lens camera according to claim 2, wherein the shutter opening permission signal is output by setting a cleaning mode for forcibly opening the shutter for cleaning the inside of the camera body. Ref type digital camera. 2. The interchangeable-lens single-lens reflex digital camera according to claim 1, wherein the shutter control means limits the opening time of the shutter within a predetermined time. 2. The interchangeable-lens single-lens reflex digital camera according to claim 1, wherein the shutter control unit can prohibit a shutter opening operation at a shutter speed longer than a predetermined time. 6. The interchangeable-lens single-lens reflex digital camera according to claim 5, wherein the shutter control means opens the shutter when a shutter opening permission signal is output. 7. The interchangeable-lens single-lens camera according to claim 6, wherein the shutter opening permission signal is output by setting a cleaning mode in which the shutter is forcibly opened for cleaning the inside of the camera body. Ref type digital camera. 6. The interchangeable-lens single-lens reflex digital camera according to claim 5, wherein the shutter control means limits the opening time of the shutter within a predetermined time.

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