JP2003023563A - Foreign matter detecting device and foreign matter detecting method for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a user to readily find but that a foreign matter causing interference with photographing is adhered with foreign matter detection prior to photographing, by displaying the amount of the foreign matter considering the size and position of the foreign matter stuck near an imaging element of a camera. SOLUTION: A shutter 107 is made open, while preventing luminous flux from outside from being incident into an imaging element 116, and the element 116 is illuminated by an illuminating device 118 of the camera. Then, a foreign matter stuck on a low-pass filter or on an infrared cutting filter is detected on the basis of an output signal from the element 116, the foreign matter is evaluated by changed weighting, according to the position or size of the foreign matter. Accordingly, the adhering state of the foreign matter is displayed for a photographer with evaluation close to human sensitivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a foreign substance attached to an image pickup optical system of a camera having an image pickup element, and evaluates the amount of the foreign substance attached in an easily understandable manner. It is about the method.

[0002]

2. Description of the Related Art In a digital single-lens reflex camera with an interchangeable lens, foreign matter such as dust and dirt inside the camera moves due to lens exchange, mirror driving, and shutter operation, and the image is near the cover glass of the image sensor or the image sensor. It may adhere to the surface of the optical low pass filter or infrared cut filter that is placed. When shooting is performed with the foreign matter attached, the shadow of the foreign matter is projected on the image pickup element together with the subject image, which may prevent good shooting.

In order to solve such a problem, an optical filter such as a low-pass filter or an infrared cut filter is placed away from the image pickup device, and a clean closed space is provided between the optical filter and the image pickup device. A structure that prevents foreign matter from entering the vicinity of the image sensor has been proposed.

Further, Japanese Patent Application Laid-Open No. 11-234543 proposes a video camera for detecting dirt of a photographing lens from an output signal of an image pickup device. This is to detect the dirt of the photographing lens by detecting a fixed low frequency component in the photographed image while photographing a moving image.

Japanese Unexamined Patent Publication No. 11-249004 proposes a detection method when a foreign substance is attached to an optical system of a phase difference detection system used in a single-lens reflex camera and a correction means of an output signal of an image sensor. There is. This is because the difference value between adjacent pixels of the output signal of the image sensor which is uniformly illuminated is integrated, and the foreign matter is detected depending on whether the integrated value is larger than a predetermined value or not. The sensitivity correction data of each pixel is changed so that the output signal of the image sensor lowered by the foreign matter becomes a normal value.

[0006]

However, in a single-lens reflex camera or the like in which the flange back of the interchangeable lens is fixed, if the image pickup device is small, the quick return mirror can be made small, so that the distance between the optical filter and the image pickup device is increased. Although it has been possible to secure a space for taking such a measure, it has become difficult to secure a space for taking such a measure due to the increase in size of the image pickup device accompanying the increase in the number of pixels in recent years.

Further, depending on the location and size of such foreign matter and the aperture value of the photographing lens, the shadow of the foreign matter may be blurred on the image sensor, and the adverse effect of the foreign matter may be difficult to see. There is a problem that the photographer continues shooting without noticing the adhesion of foreign matter, and after shooting, notices the adverse effect of the foreign matter in scenes with different shooting conditions.

For this reason, there is an increasing need to detect foreign matter that may adversely affect the shooting result before shooting and to make an easy-to-understand evaluation in consideration of the influence on the shooting result.

The present invention has been made by paying attention to the above-mentioned problems, and it is possible to easily know whether or not there is a foreign substance which interferes with the photographing before photographing, and the foreign substance on the photographed image. It is an object of the present invention to provide a foreign matter detection device and a foreign matter detection method for a camera that can prevent the reflection of an image.

[0010]

A foreign matter detection device and a foreign matter detection method for a camera according to the present invention are configured as follows.

(1) A foreign matter detecting device for a camera with interchangeable lenses, wherein foreign matter detecting means for detecting foreign matter adhering to the vicinity of an image pickup element in the camera body and weighting are changed depending on the position of the adhering foreign matter for evaluation. An evaluation means is provided.

(2) A foreign matter detecting device for a camera with interchangeable lenses, wherein foreign matter detecting means for detecting foreign matter attached to the vicinity of the image pickup device in the camera body and weighting depending on the size of the attached foreign matter are evaluated. It has an evaluation means to do so.

(3) A foreign matter detecting device for a camera with interchangeable lenses, the foreign matter detecting means for detecting foreign matter adhering to the vicinity of the image pickup device in the camera body, and the weighting being changed depending on the position and size of the adhering foreign matter. The evaluation means is provided for evaluation.

(4) A foreign matter detecting device for a camera with interchangeable lenses, the foreign matter detecting means for detecting foreign matter adhering to the vicinity of the image pickup device in the camera body, and the weighting being changed depending on the position and size of the adhering foreign matter. The evaluation means for evaluating the amount of the foreign matter is provided by the total amount of the weighted evaluation values.

(5) In the above (4), a display means for displaying the total amount of the weighted foreign matter in stages is provided.

(6) In the above (4), there is provided a changing means for changing the weighting parameter by size according to the open aperture value of the taking lens.

(7) In the above (4), the photographer has a changing means for arbitrarily changing the weighting parameter according to the size.

(8) A foreign object detecting method for a camera with interchangeable lenses, in which foreign particles attached to the vicinity of the image pickup device in the camera body are detected, and weighting is changed depending on the position of the attached foreign particles for evaluation. .

(9) A foreign object detecting method for a camera with interchangeable lenses, which detects foreign objects adhering to the vicinity of an image pickup device in the camera body and evaluates the weight by changing the size of the adhering foreign particles. did.

(10) A method of detecting foreign matter in a camera with interchangeable lenses, which detects foreign matter adhering to the vicinity of an image pickup device in the camera body and evaluates the weight by changing the position and size of the adhering foreign matter. I did it.

(11) A method for detecting foreign matter in a camera with interchangeable lenses, which detects foreign matter adhering to the vicinity of an image pickup device in the camera body, changes weighting according to the position and size of the adhering foreign matter, and weights the foreign matter. The amount of the foreign matter was evaluated by the total amount of the evaluated values.

(12) In the above item (11), the weighted total amount of foreign matter is displayed in stages.

(13) In the above (11), the weighting parameter by size is changed according to the open aperture value of the taking lens.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a cross-sectional view showing the structure of a camera according to the present invention, showing a standby state of a digital single lens reflex camera using an interchangeable lens.

In FIG. 1, reference numeral 1 denotes a camera body, and an interchangeable lens 20 which can be attached to and detached from the camera body 1 is fixed by a mount portion 2 of the camera and a mount portion 22 of the lens. Electrical contact is made by contact with the contact portion 24, and communication for controlling power supply and power supply from the camera body 1 to the interchangeable lens 20 is performed via the contact portions 3 and 24.

The light flux transmitted through the taking lens 21 of the interchangeable lens 20 enters the main mirror 5 of the camera. The main mirror 5 is a half mirror, and the light flux reflected here is guided to the finder, and the transmitted light flux is reflected downward by the sub-mirror 7 and guided to the focus detection device 5.

The focus detection device 5 detects the defocus amount of the taking lens 21 and calculates the lens drive amount for driving the taking lens 21 so that the taking lens 21 is in focus. When this lens driving amount is sent to the lens 20 via the contact points 3 and 24, the lens controls a motor (not shown) to drive the taking lens 21 to perform focus adjustment.

The main mirror 5 is adhesively fixed to a mirror holding frame 6, and a frame body 10 is rotatably supported by a hinge shaft 6a. The sub mirror 7 is adhesively fixed to the sub mirror holding frame 8, and the sub mirror holding frame 8 is rotatably supported by the main mirror holding frame 6 by a hinge shaft (not shown).

The light beam guided to the finder by the main mirror 5 forms a subject image on the focusing plate 9, and the photographer can observe the subject image on the focusing plate via the pentaprism 11 and the eyepiece lens 12. Is configured.

A shutter 13 is arranged behind the sub-mirror 7, and its shutter curtain 13a is normally closed. Behind the shutter 13, there is an optical filter 14 that integrates an optical low-pass filter and an infrared cut filter.
The light flux that has passed through is incident on the image pickup device 15 disposed further rearward.

The LED 4 is an illuminating device for illuminating the image pickup device 15 from the lower surface side of the mirror box when detecting a foreign substance attached near the optical filter 14.

In a digital single-lens reflex camera equipped with such a large image pickup device 15, the focus plate 9 and the main mirror 5 cannot be downsized, so that a structure in which the distance between the optical filter 14 and the image pickup device 15 is widened is used. It is difficult to take. Therefore, the distance between the image sensor 15 and a foreign substance such as dust adhering to the optical filter is reduced,
The shadow of the foreign matter enters the subject image on the image sensor without being greatly blurred. Then, the image photographed in such a state has a black shadow of a foreign substance, and the image quality is significantly deteriorated. Therefore, it is necessary to detect the adhesion of foreign matter before the image capturing so that cleaning can be performed if necessary.

FIG. 2 is a sectional view showing an operation state of the digital single-lens reflex camera having the above-mentioned structure when detecting a foreign substance.

In order to detect foreign matter, first, the main mirror 5 and the sub-mirror 7 are retracted by a mirror-up operation in order to darken the inside of the mirror box, and the main-mirror holding frame 6 and the sub-mirror holding frame 8 are used for the eyepiece of the finder. The light flux incident from 12 is blocked. Next, the light flux incident from the photographing lens 21 is blocked by the diaphragm blades 23a of the lens diaphragm 23 by communication through the contact points 3 and 24 of the camera and the lens. Then, the shutter curtain 13a of the shutter 13 is moved to open the shutter 13.

In this way, the light from the outside is prevented from entering the mirror box, and the LED 4 of the lighting device is
After the light blocking member between the image pickup device 15 and the image pickup device 15 is removed, the image pickup device 15 is uniformly illuminated by the illumination device. In this state, the image sensor 15 accumulates charges and reads out the image signal, and detects the position and size of the foreign matter on the optical filter from the image signal.

At this time, the shadow of the foreign matter generated by the light flux that has passed through the taking lens 21 is blurred depending on the aperture value of the taking lens 21, and the shadow of the foreign matter is greatly blurred when a bright lens is used in an open state. Small foreign objects cannot be found. Further, when the diaphragm 23 is stopped down or a dark lens is used, the shadow of the foreign matter is not so blurred, so that the shadow of a relatively small foreign matter can be found.

As described above, when a foreign substance is detected using the light flux transmitted through the taking lens 21, the size of the detectable foreign substance varies depending on the taking lens 21 and the photographing conditions.
Stable foreign matter cannot be detected. In addition, the taking lens 21
Since the light flux that has passed through also forms a subject image on the image sensor, the subject image may be erroneously determined as a foreign matter, and accurate foreign matter detection cannot be performed.

Therefore, in this embodiment, an LED close to a point light source is used.
By illuminating the image pickup device 15 with 4, it is possible to detect a small foreign substance that is less likely to cause a shadow of the foreign substance to be blurred, and to accurately and stably detect the foreign substance because it is not affected by the photographing conditions and the photographing lens 21.

The weight is increased near the center of the screen where the foreign matter is attached, and is decreased in the peripheral area. When the size of the foreign matter is large, the weighting is increased, and when it is small, the weighting is decreased. By calculating the sum of the weighted values and displaying the amount of foreign matter adhered, it becomes possible to notify the state of foreign matter adherence on the basis of a human-like reference.

Next, the principle of the above-mentioned foreign matter detection will be described with reference to FIG. FIG. 3 is an enlarged cross-sectional view showing details near the image sensor.

The image pickup element 15 is roughly divided into the image pickup section 15
a, ceramic package 15b, cover glass 15d
It consists of 15c is a lead terminal.

In the state shown in FIG. 3, a foreign substance 19 is attached to the surface of the optical filter 14 immediately in front of the cover glass 15d of the image pickup device 15. The foreign substance 19 blocks the illumination light from the illumination device, and the shadow 19a. Is made. This shadow 19a causes the output signal of the image pickup device 15 in this portion to be lower than the output signal in the surrounding non-shadow portion, so that the portion where the output signal is reduced is attached to the optical filter 14. It is possible to detect the position and size of the foreign matter that has been removed.

FIG. 4 is a block diagram showing the electric circuit configuration of the camera according to the present invention. The camera body 100 (camera body 1) and the interchangeable lens 200 (interchangeable lens 20) are composed of communication contact portions 120 and 220 (contact portions 3 and 24) and power supply contact portions 121 and 221 (contact portions 3 and 24). It is connected.

The camera body 100 includes a main mirror 101.
(Main mirror 5), mirror drive circuit 105 for driving the sub-mirror 102 (sub-mirror 7), photographing lens 20
1 (photographing lens 21), a focus detection device 103 that detects the defocus amount, a photometric circuit 104 that measures the brightness of the subject to determine the exposure during shooting, and a shutter curtain (shutter curtain 13a) of the shutter 107 (shutter 13).
The shutter driving circuit 106 for driving the image pickup device, the illumination device 118 that illuminates the image pickup element 116 (image pickup element 15) when detecting foreign matter near the optical filter 117 (optical filter 14), and the image pickup element 116 are driven to capture an image. An image sensor driving circuit 112 for reading signals, a RAM 113 for storing the read image signals, a signal processing circuit 114 for converting the image signals stored in the RAM 113 into predetermined image data, and a flash for storing the image data. A memory 115, a camera power supply circuit 109 that supplies electric power to each electric circuit of the camera and a lens, a camera CPU 108 that controls the lens by controlling these circuits and communication with the lens, a switch input circuit 110, and an LCD.
The LCD drive circuit 111 drives a panel (display unit).

Further, the foreign matter detecting means for detecting the foreign matter adhering to the vicinity of the image pickup device, the weighting is changed according to the position and the size of the foreign matter, and the amount of foreign matter is evaluated by the total weighted evaluation value. Means, changing means for changing the weighting parameter of the foreign matter according to the open aperture value of the photographing lens 201, and changing means for allowing the photographer to arbitrarily change the weighting parameter of the foreign matter, the camera CPU
It is composed of 108.

The interchangeable lens 200 is based on the defocus amount of the focus detection device 103 of the camera.
A focus control circuit 206 for controlling a focus drive motor 205 that adjusts the focus of the aperture, an aperture control circuit 202 that controls an aperture drive motor 203 that drives an aperture blade (aperture blade 23a) of the aperture 204 (aperture 23), and a lens A lens power supply circuit 208 for supplying electric power to each electric circuit, and a lens CPU 207 for controlling these electric circuits based on the communication result with the camera CPU 108.

When the light flux entering from the finder optical system is blocked, the camera CPU 108 controls the mirror drive circuit 105 to bring the main mirror 101 and the sub mirror 102 into the mirror-up state. Shooting lens 201
When blocking the light flux coming from the camera CPU
When the lens CPU 207 sends a command to the lens CPU 207 to close the diaphragm 204 and shield it from light, the lens CPU 207 that receives the command controls the diaphragm control circuit 202 to drive the diaphragm drive motor 203 by a predetermined amount, and the diaphragm blades of the diaphragm 204 The light flux of the taking lens 201 is blocked.

To open the shutter 107, the shutter drive circuit 1 is operated by the camera CPU 108.
By controlling 06, the shutter curtain is moved to open the shutter 107.

When detecting the position and size of the foreign matter, the illumination device 118 is used to detect the image pickup element 11.
6 is illuminated, and the shadow of the foreign matter attached to the optical filter 117 is detected from the image pickup signal read from the image pickup element 116. In order to detect the adherence of foreign matter from this image pickup signal,
The signal processing circuit 114 converts the image data into image data and extracts a luminance component from the image data. Then, it is determined that the foreign matter is attached to the portion whose luminance value is smaller than a predetermined value, and the foreign matter attachment position and the size are detected from the position and the size of the portion whose luminance value is low. Has become.

When the attachment of the foreign matter is detected, the camera C
The PU 108 weights the detected foreign matter according to its size and the position where it is attached, and calculates the total value of the weighted values. Then, when notifying the adhered state of the foreign matter on the LCD panel, a four-stage display corresponding to the total value is displayed.

The photographer can easily know how much foreign matter is attached by looking at the step display on the LCD, and can easily determine whether or not cleaning for removing foreign matter must be performed. . In addition, since it is possible to easily know the adhered state of the foreign matter, it is possible to prevent the foreign matter from being caught in the captured image by performing cleaning as necessary.

That is, according to the present embodiment, the shutter 107 is opened by blocking the light from the outside by the light blocking means so that the light flux from the outside does not enter the image sensor 116, and the illumination means arranged in the mirror box of the camera. The image sensor 116 is illuminated by. Then, the foreign matter adhering to the optical low-pass filter or the infrared cut filter is detected from the output signal of the image pickup device 116 at this time, and the weighting is changed according to the position and the size of the adhering foreign matter to evaluate the foreign matter. As a result, it becomes possible to evaluate the state of adhesion of foreign matter that is close to human sensibilities, and it is possible to make a display that the photographer can easily understand.

Further, by displaying in stages according to the total amount of the weighted evaluation values, the photographer can easily and accurately grasp the amount of foreign matter attached. In addition, the amount of adhering foreign matter that can be tolerated in the actual use environment varies depending on the shooting conditions and the photographer, and the photographer considers these factors to determine whether to perform cleaning to remove the foreign matter. By weighting or displaying in stages, it becomes possible to more accurately determine whether or not to perform cleaning.

Further, by changing the weighting parameter according to the photographing condition (aperture value) or allowing the photographer to arbitrarily change the weighting parameter, a more appropriate amount of adhered foreign matter can be obtained. It becomes possible to display.

Next, the operation of this embodiment will be described with reference to the flow charts of FIGS. The control processes shown in the flowcharts of FIGS. 5 to 9 and the later-described flowcharts of FIGS. 12 to 18 are executed according to a program stored in advance by the camera CPU 108 of FIG.

FIG. 5 is a flow chart showing the operation of foreign matter detection. When this foreign substance detection subroutine is called, the process proceeds to step (S101), the foreign substance detection is started, and the process proceeds to step (S102). Step (S102)
Then, based on the communication data of the camera CPU 108, the lens CPU 207 controls the diaphragm drive circuit 202 to drive the diaphragm drive motor 203 and close the diaphragm blades of the diaphragm 204 to block the light flux of the taking lens 201.

In step (S103), the mirror drive circuit 105 is controlled to perform the mirror-up operation to block the light beam incident from the finder. Step (S1
In 04), by controlling the shutter drive circuit 106, the shutter front curtain is made to travel and the shutter 107 is moved.
To open.

When the preparation for detecting the foreign matter is completed, the LED of the illumination device 118 is turned on to illuminate the image pickup element 116 in the subsequent step (S105). Then, the step (S1
In 06), the image pickup device driving circuit 112 controls the image pickup device 116 in a state where the image pickup device drive circuit 112 illuminates the LED to start the accumulation of charges in the light receiving portion. When the charge is accumulated for a predetermined time after the charge accumulation is started, the charge accumulation is ended in the subsequent step (S107).

In step (S108), the lighting device 11
The LED of No. 8 is turned off, and in the subsequent step (S109), the charge accumulated in the light receiving portion of the image sensor 116 is transferred to the transfer path, and the charge (imaging signal) of each pixel is sequentially read out as a voltage, which is A / D. It is converted into digital image data by the converter and stored in the RAM 113.

In step (S109), the RAM 113
The imaging data stored in the
In step 110), a foreign matter detection calculation is performed to determine the foreign matter adhesion state. Details of this arithmetic processing will be described later.

In step (S111), since the foreign substance detection processing is completed, the shutter drive circuit 106 is controlled to close the shutter 107 in order to return the camera to the initial state, and in the subsequent step (S112), the mirror drive circuit 10 is closed.
5, the mirrors 101 and 102 are moved down, and in step (S113), the diaphragm control circuit 202 controls the diaphragm drive motor 203 to fully open the diaphragm blades of the diaphragm 204.

When all the foreign matter detecting operations are completed, the foreign matter detecting subroutine is returned in step (S114).

FIG. 6 is a flowchart of a subroutine for performing the above-mentioned foreign matter detection calculation. Step of FIG. 5 (S11
When the foreign matter detection calculation subroutine is called in 0),
The process proceeds to step (S201) to start the foreign matter detection calculation.

In step (S202), the variable GTOTAL for evaluating the amount of foreign matter adhered is initialized to 0, and in the subsequent step (S203), the image pickup data stored in the RAM 113 is converted into image data by the signal processing circuit 114. To generate luminance data and color data for each pixel.

In step (S204), only the brightness data is extracted from the image data composed of the brightness data and the color data. In the subsequent step (S205), the value of the brightness data is compared with a predetermined value, and an area of low brightness whose brightness is lower than the predetermined value is extracted.

In step (S206), step (S206
If there is a low-brightness area extracted in 205), it is determined that foreign matter is attached and the process proceeds to step (S207). If not, it is determined that there is no foreign matter attached and step (S212). ).

In step (S212), it is determined that no foreign matter is attached, and therefore the variable GLEV indicating the foreign matter attachment level is set.
EL is reset to 0 and the process proceeds to step (S216).
Further, in step (S207), since it is determined that the foreign matter is attached, the weighting calculation is performed according to the position where the foreign matter is attached. The details of the weighting calculation here will be described later, but the weighting is increased toward the center of the screen,
The weight is reduced toward the periphery.

In step (S208), a weighting operation is performed on each foreign matter according to its size. Although details of the weighting calculation here will be described later, the larger the weight, the larger the weight, and the smaller the weight, the smaller the weight.

In step (S209), GTOTAL for evaluating the amount of foreign matter attached is calculated. Specifically, the total value of all the foreign substances weighted in the steps (S207) and (S208) is calculated.

In step (S210), it is determined whether the evaluation value GTOTAL of the amount of foreign matter attached is smaller than 6, and if GTOTAL <6, it is determined that the amount of foreign matter attached is small, and the process proceeds to step (S213). "1" is input to the variable GLEVEL indicating the foreign matter adhesion level. Also, G
If TOTAL <6 is not satisfied, the process proceeds to step (S211).

In step (S211), it is determined whether the evaluation value GTOLAT of the amount of adhered foreign matter is smaller than 16, and if GTOTAL <16, it is determined that the adhered foreign matter slightly adversely affects the photographing result. Step (S2
Proceed to 14), and the variable GLEVEL indicating the foreign matter adhesion level.
Enter "2" in. If GTOTAL <16, the process proceeds to step (S215).

In step (S215), it is determined that the foreign matter that has adhered has a great influence on the photographing result, and "3" is input to the variable GLEVEL that indicates the foreign matter adhesion level.
Then, the steps (S212), (S213),
When the variable GLEVEL indicating the foreign matter adhesion level is set to any of 0 to 3 in any of the steps (S214) and (215), the process proceeds to step (S216) to end the foreign matter detection calculation subroutine and return. To do.

Next, the weighting calculation according to the above-mentioned foreign matter attachment position will be described. Here, as shown in FIG. 10, the adhesion position of the foreign matter on the photographing screen is divided into three zones A, B, and C.
The weighting is changed for each zone, and the weighting calculation is performed for all the foreign matters. Figure 1
In the example of 0, 13 large and small foreign matter are attached,
(1) to GD (5) are zones A, GD (6) to GD (1
0) is zone B, and GD (11) to GD (13) are zone C.

FIG. 7 is a flowchart of the weighting calculation based on the adhesion position. When this subroutine is called in step (S207) of FIG. 6, step (S301)
Then, the weighting calculation based on the adhesion position is started.

In step (S302), the number of adhering foreign matters is counted, the counted number is stored in a variable GN, and 1 to GN is applied to each foreign matter.
Numbering up to. Subsequent steps (S30
In 3), the value of the counter N is initialized to "0". Then, in step (S304), the counter N is set to 1
Add and count up.

In step (S305), it is judged whether or not the place where the N-th foreign matter is attached is within the range A in FIG. 10, and if it is within the range A, the process proceeds to step (S307). If not, the process proceeds to step (S306). In step (S306), it is determined whether or not the place where the N-th foreign matter is attached is within the range of B in FIG. 10, and if it is within the range of B, the process proceeds to step (S308), and otherwise. Go to step (S309).

At step (S307), since the zone A is the peripheral portion of the screen, the weighting is the smallest and GD (N) is set to 1
Enter. In step (S308), since zone B is at an intermediate position, weighting is slightly increased and 2 is input to GD (N). In step (S309), since zone C is an important position near the center of the screen, the weighting is increased and GD is increased.
Enter 3 in (N). In this way, the weighting of zone A is 1, the weighting of zone B is 2, and the weighting of zone C is 3.

Steps (S307), (S30
When either of 8) and (S309) is executed, the step (S
The process proceeds to 310) and compares the counter N with the number of foreign substances GN. If N = GN, the process proceeds to step (S311) in which the weighting process for all foreign matters has been completed, and otherwise returns to step (S304). Then, in step (S311), this subroutine is ended and the process returns.

Next, the weighting calculation based on the size will be described. In the example of FIG. 10, GD (2) and GD (10)
Is a large foreign substance having a size of 70 μm or more, and is conspicuous under any photographing condition, and therefore the weighting becomes the highest. The GD (5) and GD (8) are medium sizes of 30 to 70 μm, and are not so noticeable when shooting with a bright lens, but are conspicuous when shooting with a dark lens. Therefore, the weighting becomes medium. GD (1,3,4,6,7,9,1
1, 12 and 13) have a size of 30 μm or less, which is relatively small and inconspicuous unless the image is narrowed down considerably, the weighting becomes the lowest.

FIG. 8 is a flowchart of the weighting calculation based on the size of the adhered foreign matter. Step of FIG. 6 (S2
When this subroutine is called in step 08), the process proceeds to step (S401) to start weighting calculation based on the size of the foreign matter.

In step (S402), the counter N
The value of is initialized to "0". Then, the step (S
In 403), the counter N is incremented by 1, and the counter is counted up. In the subsequent step (S404), it is determined whether the size of the foreign matter is 70 μm or more or less. If it is 70 μm or more, the process proceeds to step (S406), and if it is less than 70 μm, the process proceeds to step (S405).

In step (S405), it is determined whether the size of the foreign matter is 30 μm or more or less. If it is 30 μm or more, the process proceeds to step (S407), and if it is less than 30 μm, the process proceeds to step (S408).

At step (S406), GD of FIG.
Since it is a large foreign substance as shown in (2), 3 is added to the value of GD (N) in order to increase the weighting. Step (S40
In 7), since it has an intermediate size like GD (8), 2 is added to the value of GD (N) to perform intermediate weighting. In step (S408), since it is a small foreign matter like GD (1), 1 is added to the value of GD (N) in order to lower the weight.

Step (S406), step (S)
407) or step (S408) is executed, the process proceeds to step (S409). Step (S40
In 9), the counter N is compared with the number of foreign substances GN, and N
= GN, the process proceeds to step (S410) in which the weighting process for all the foreign matters has been completed, and otherwise returns to step (S403). Then, the step (S41
In 0), this subroutine is finished and the process returns.

In this way, weighting is performed according to the position and size of the foreign matter. For example, in the example of FIG. 10, weighting is performed as follows. Since GD (1) is small in zone A, GD (1) =
1 + 1 = 2 Since GD (2) is large in zone A, GD (2) =
1 + 3 = 4 GD (5) is zone A and medium size, so GD (5) =
1 + 2 = 3 GD (6) is small in zone B, so GD (6) =
2 + 1 = 3 GD (8) is zone B and medium in size, so GD (1) =
2 + 2 = 4 GD (10) is zone B and medium in size, so GD (1
0) = 2 + 2 = 4 GD (11) is small in zone C, so GD (1)
= 3 + 1 = 4 Next, when the total value calculation subroutine is called in step (S209) of FIG. 6, the weighted foreign matter GD
In order to calculate the total value of the values of (N), the process proceeds to step (S501) in FIG.

At step (S502), the counter N
Is initialized to "0", and the subsequent step (S50
In 3), add 1 to the counter N and count up. Then, in step (S504), the total value GTOTA
The value of GD (N) weighted to L is added, and the process proceeds to step (S505).

At step (S505), the counter N
And the number GN of foreign matters are compared, and if N = GN, the step of weighting processing for all foreign matters is completed (S50).
If not so, go to step (S503). Then, in step (S506), this subroutine is ended and the process returns.

Here, the display of the amount of adhered foreign matter is based on GLEVE determined by the weighted total value GTOTAL.
Although it is displayed in stages according to the value of L, the display form is as shown in FIG.
The bar display as shown in FIG. 1 is performed so that the adhered state of the foreign matter can be sensed.

The display of FIG. 11 is a bar display displayed on a liquid crystal display panel arranged on the top or back of the camera, and also serves as a display unit for displaying the remaining battery capacity, the remaining memory capacity, and the like. Is also good.

If GLEVEL = 1, then FIG.
The display is not turned on as in (a) of 1 and GLEVEL =
In the case of 1, only one segment of the bar is displayed as shown in (b) of the figure, when the GLEVEL = 2, only two segments of the bar are displayed as in (c), and in the case of GLEVEL = 3 As shown in (d), the bar is fully displayed in 3 segments.

The photographer looks at this display and looks at the optical filter 1
It is possible to know the state of adhesion of the foreign matter to 17 and to perform cleaning as necessary, so that the foreign matter can be removed before shooting, and shooting can always be performed in a good condition.

(Second Embodiment) In the second embodiment, the photographer can arbitrarily set the weighting value and the determination threshold value so that the foreign matter can be detected and displayed according to his / her own sensitivity. However, since the main structure is the same as that of the first embodiment, only different parts will be described here.

FIG. 12 is a flow chart showing the foreign substance detection operation of this embodiment, and shows the operation for the photographer to set the weighting value and the judgment threshold value. When this subroutine is called, the process proceeds to step (S601).

In step (S602), a threshold value GJ1 for determining whether the amount of foreign matter adhered is relatively small is set, and in the subsequent step (S603), it is determined whether the amount of foreign matter adhered is considerably large. The threshold GJ2 is set.

In step (S604), the weighting value GA1 is set in the range of A in FIG. 10 for the foreign matter adhesion position, and in the subsequent step (S605), the foreign matter adhesion position is set to the value shown in FIG.
The weighting value GA2 is set within the range of B, and the step (S
In 606), the weighting value GA3 is set within the range of C of FIG.

Next, in step (S607), the weighting value GB1 when the size of the foreign matter is smaller than 30 μm is set, and in the following step (S608), the weighting value when the size of the foreign matter is 30 μm or more and less than 70 μm. GB2
Is set, and in step (S609), the weighting value GB3 when the size of the foreign matter is 70 μm or more is set.

When the setting of the various parameters described above is completed, the process exits this subroutine in step (S610) and returns.

FIG. 13 is a subroutine of the foreign matter detection calculation processing in the second embodiment. The difference from the first embodiment is step (S710) and step (S711).
Is a part for determining the amount of adhered foreign matter, and the step (S7
01) to step (S709) are the same as step (S2) of FIG.
01) to step (S209), corresponding to step (S
712) to step (S716) are steps (S21).
2) to step (S216).

Step (S710), Step (S71)
In 1), steps (S602) and (S60) of FIG.
Judgment is made based on the values of GJ1 and GJ2 set in 3), and if GJ1 and GJ2 are set to be smaller than the standard value, it is displayed that even a small amount of foreign matter needs cleaning, and GJ1 and GJ2 are displayed. If is set to be larger than the standard value, the indication that cleaning is required will not be displayed unless a large amount of foreign matter is attached. in this way,
In the present embodiment, it becomes possible to detect an appropriate foreign substance according to the photographer or the subject.

FIG. 14 is a flow chart of a subroutine for weighting calculation based on the foreign matter attachment position in this embodiment. The difference from the first embodiment is the step (S807)-
In step (S809), step (S60) in FIG.
4) to the weighting value GA1 set in (S606),
Since the respective weighting operations are performed based on GA2 and GA3, it is possible to arbitrarily change the weighting depending on the adhesion position. This allows the photographer to arbitrarily set whether to check the center emphasis or the uniform check.

The steps (S801) to (S806) of FIG. 14 correspond to the steps (S301) to (S306) of FIG. 7, and steps (S810) and (S8).
11) corresponds to steps (S310) and (S311).

FIG. 15 is a flow chart of a subroutine for weighting calculation based on the size of the foreign matter in this embodiment. The difference from the first embodiment is that the step (S90
6) to step (S908), step (S) of FIG.
607) to (S609), the weighting value GB set
Since the respective weighting operations are performed based on 1, GB2, GB3, the weighting according to the size of the foreign matter can be arbitrarily changed. With this, the photographer can set whether to focus on the large foreign matter or to attach importance to the small foreign matter.

Steps (S901) to (S905) in FIG. 15 correspond to steps (S401) to (S405) in FIG. 8, and steps (S909) and (S9).
10) corresponds to steps (S409) and (S410).

(Third Embodiment) In the actual photographing, the size of the foreign matter in question differs depending on the F value of the lens used. For example, with a bright (small F-number) lens, even a slightly larger foreign substance may cause no problem because the foreign substance has a large blur on the image sensor. On the other hand, in a dark (large F-number) lens, even a small foreign substance may cause a problem because the foreign substance does not have a large shadow on the image sensor.

In the third embodiment, in order to solve the above problem, the open F value of the taking lens is detected, and the weighting calculation by the size of the foreign matter is changed according to the F value. . In this way, by changing the weighting calculation of the size according to the taking lens, it becomes possible to more accurately select the foreign matter in question and issue an appropriate cleaning warning.

Since the main structure of this embodiment is the same as that of the first embodiment, only different parts will be described here.

FIG. 16 is a subroutine of the foreign matter detection calculation processing of this embodiment. The difference from the first embodiment is the determination threshold setting subroutine of the size of step (S1002) and the weighting calculation subroutine by the size of step (S1010), and the other operations are the same as those of the first embodiment.

Step (S1011) and step (S1003) to step (S1009) of FIG. 16 correspond to step (S201) and step (S202) to step (S207) of FIG. 6, and step (S1011) to
(S1017) includes steps (S209) to (S216).
It corresponds to.

FIG. 17 is a flowchart of the foreign matter detection calculation processing in this embodiment, showing a threshold value setting subroutine for determining the size. When this subroutine is called, the process proceeds to step (S1101).

At step (S1102), the open F value (FN) of the taking lens is read by communication between the camera and the lens. At subsequent step (S1103), the FN obtained at step (S1102) is less than 2.8. Whether or not it is a bright lens with an FN of less than 2.8, the process proceeds to step (S1105), and if not, the process proceeds to step (S1104).

In step (S1104), it is determined whether or not the FN obtained in step (S1102) is less than 5.6. If the lens has an FN of 2.8 or more and less than 5.6, step (S1106). If it is a dark lens having an FN of 5.6 or more, the process proceeds to step (S1107).

At step (S1105), since the bright lens is attached, the size determination threshold value GC1 is set to 40.
.mu.m and GC2 to 70 .mu.m, which are larger values.
In step (S1106), since a lens having an intermediate brightness is mounted, the size determination threshold value GC1 is set to 30 μm.
m is set to an intermediate value of 60 μm. Further, in step (S1107), since a dark lens is attached, the size determination threshold value GC1 is set to 40 μm and GC2 is set to 40 μm.
Is set to a small value of 70 μm.

Then, steps (S1105) and (S1
106) or (S1107) is executed, the process proceeds to step (S1108), and this subroutine is returned.

As described above, in the subroutine of this embodiment, when the F value of the taking lens is small, the judgment threshold value GC1 is
The value of GC2 is increased, and the values of the determination thresholds GC1 and GC2 are decreased when the F value of the taking lens increases.

FIG. 18 is a flow chart showing a subroutine of weighting calculation by size in this embodiment. In this subroutine, the determination thresholds GC1 and GC set in the determination threshold setting subroutine of the size in FIG. 17 are set.
According to 2, the weighting calculation by the size is performed. Steps (S1201) to (S1203) are the steps (S401) to (S403) of FIG. 8 of the first embodiment.
The description here is omitted.

In step (S1204), it is determined whether or not the size of the foreign matter is the value of GC2 or more. If the size is CG2 or more, the process proceeds to step (S1206). move on. Step (S1
In 205), it is determined whether or not the size of the foreign matter is equal to or larger than the value of GC1, and if it is equal to or larger than CG1, step (S12)
07), otherwise go to step (S120)
Proceed to 7).

In step (S1206), weighting 3
Is added, weighting 2 is added in step (S1207), and weighting 1 is added in step (S1208).
Is added. Then, steps (S1206), (S
After executing either 1207) or (S1208), the process proceeds to step (S1209).

At step (S1209), the counter N is compared with the number GN of foreign matters, and if N = GN is not satisfied, the weighting of all the foreign matters is not completed, so step (S120).
Returning to 3), if N = GN and the weighting of all the foreign matters is completed, the process proceeds to step (S1210), and this subroutine is returned.

As described above, the criteria for weighting are different depending on whether the bright photographic lens is attached or the dark photographic lens is attached, and the darker photographic lens has a larger weight even for a small foreign matter. . For this reason, even in the case of a dark lens, a warning for cleaning is issued even if a small foreign substance is apt to show the shadow of the foreign substance in actual photographing. Also, with a bright lens in which shadows are not noticeable with small foreign matter, the cleaning warning will not be issued with small foreign matter.

Therefore, it becomes possible to appropriately detect and display the foreign matter according to the photographing conditions.

[0122]

As described above, according to the present invention,
Since the amount of adhesion can be displayed in consideration of the size and position of the foreign matter that has adhered to the vicinity of the image sensor, it is possible to detect foreign matter before shooting and easily know whether there is foreign matter that interferes with shooting. it can.

If there is a foreign substance that interferes with the photographing, the foreign substance can be removed before the photographing is started, so that the foreign substance can be effectively prevented from appearing in the photographed image.

Further, by making it possible to arbitrarily set the weight of the foreign matter and the determination threshold value, it becomes possible to perform the determination closer to the determination standard of the photographer.

Furthermore, by changing the size criterion of the foreign matter according to the brightness of the taking lens,
It becomes possible to select a foreign matter of a size that actually causes a problem and display a cleaning warning.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a standby state of a camera according to the present invention.

FIG. 2 is a sectional view showing an operation state of the camera according to the present invention when detecting a foreign substance.

FIG. 3 is a cross-sectional view showing details of the vicinity of the image sensor of the camera.

FIG. 4 is a block diagram showing a camera electric circuit configuration.

FIG. 5 is a flowchart showing a foreign matter detection operation of the first embodiment.

FIG. 6 is a flowchart showing foreign matter detection calculation processing of the first embodiment.

FIG. 7 is a flowchart showing a weighting calculation process according to the foreign matter attachment position according to the first embodiment.

FIG. 8 is a flowchart showing a weighting calculation process according to the size of the foreign matter according to the first embodiment.

FIG. 9 is a flowchart showing a total calculation process of the first embodiment.

FIG. 10 is an explanatory diagram showing a state in which a foreign object is attached to the shooting screen.

FIG. 11 is an explanatory diagram showing a display form of the amount of adhered foreign matter.

FIG. 12 is a flowchart showing a foreign matter detection operation of the second embodiment.

FIG. 13 is a flowchart showing foreign matter detection calculation processing of the second embodiment.

FIG. 14 is a flowchart showing a weighting calculation process according to a foreign substance attachment position according to the second embodiment.

FIG. 15 is a flowchart showing a weighting calculation process based on the size of a foreign substance according to the second embodiment.

FIG. 16 is a flowchart showing foreign matter detection calculation processing according to the third embodiment.

FIG. 17 is a flowchart showing foreign matter detection calculation processing according to the third embodiment.

FIG. 18 is a flowchart showing a weighting calculation process based on the size of a foreign matter according to the third embodiment.

[Explanation of symbols]

1 camera body 2 Mount section 3 contact points 4 LED 5 main mirror 6 Mirror holding frame 7 sub-mirror 8 Sub mirror holding frame 9 focus plate 11 Penta prism 12 eyepiece 13 shutter 14 Optical filter 15 Image sensor 19 foreign material 20 interchangeable lens 21 Shooting lens 22 Mount 23 Aperture 24 contact points 100 camera body 101 Main mirror 102 submirror 103 Focus detection device 104 Photometric circuit 105 Mirror drive circuit 106 shutter drive circuit 107 shutter 108 Camera CPU 109 camera power supply circuit 112 Image sensor drive circuit 113 RAM 114 signal processing circuit 115 flash memory 116 image sensor 117 Optical filter 118 Lighting device 200 interchangeable lens 201 shooting lens 202 Aperture control circuit 203 Aperture drive motor 204 aperture 205 Focus drive motor 206 Focus control circuit 207 lens CPU 208 Lens power supply circuit

Claims (13)

[Claims] 1. A foreign matter detection device for a camera with interchangeable lenses, wherein foreign matter detection means for detecting foreign matter adhered in the vicinity of an image sensor in a camera body, and evaluation by changing weighting depending on the position of the adhered foreign matter. A foreign matter detection device for a camera, comprising: 2. A foreign matter detection device for a camera with interchangeable lenses, wherein foreign matter detection means for detecting foreign matter attached to the vicinity of an image sensor in a camera body, and weighting are changed according to the size of the attached foreign matter for evaluation. A foreign matter detection device for a camera, comprising an evaluation means. 3. A foreign matter detection device for a camera with interchangeable lenses, wherein foreign matter detection means for detecting foreign matter adhered in the vicinity of an image sensor in the camera body, and weighting is changed depending on the position and size of the adhered foreign matter. A foreign matter detection device for a camera, comprising an evaluation means for evaluating. 4. A foreign matter detection device for a camera with interchangeable lenses, the foreign matter detection means for detecting foreign matter adhering to the vicinity of an image sensor in the camera body, and the weighting being changed according to the position and size of the adhered foreign matter, A foreign matter detection device for a camera, comprising: an evaluation unit that evaluates the amount of the foreign matter based on the total amount of the weighted evaluation values. 5. The foreign matter detection device for a camera according to claim 4, further comprising display means for displaying the weighted total amount of foreign matter in stages. 6. The foreign matter detecting device for a camera according to claim 4, further comprising changing means for changing a weighting parameter according to a size according to an open aperture value of the taking lens. 7. The foreign matter detecting device for a camera according to claim 4, further comprising changing means for allowing a photographer to arbitrarily change a weighting parameter depending on a size. 8. A foreign matter detection method for a camera with interchangeable lenses, wherein foreign matter adhered in the vicinity of an image sensor in the camera body is detected, and weighting is changed according to the position of the adhered foreign matter for evaluation. A foreign matter detection method for a camera, characterized by: 9. A foreign matter detecting method for a camera with interchangeable lenses, wherein foreign matter adhering to the vicinity of an image pickup device in a camera body is detected, and weighting is changed according to the size of the adhering foreign matter for evaluation. A foreign matter detection method for a camera characterized by the above. 10. A foreign matter detection method for a camera with interchangeable lenses, wherein foreign matter adhered in the vicinity of an image sensor in a camera body is detected, and weighting is changed according to the position and size of the adhered foreign matter for evaluation. A foreign matter detection method for a camera, characterized in that 11. A foreign matter detection method for a camera with interchangeable lenses, which detects foreign matter adhered in the vicinity of an image sensor in a camera body, changes weighting according to the position and size of the adhered foreign matter, and weights the foreign matter. A foreign matter detection method for a camera, wherein the amount of foreign matter is evaluated based on a total amount of the evaluation values. 12. The foreign matter detection method for a camera according to claim 11, wherein the weighted total amount of foreign matter is displayed in stages. 13. A foreign matter detecting method for a camera according to claim 11, wherein the weighting parameter according to the size is changed according to the open aperture value of the taking lens.