JP4614006B2 - camera - Google Patents

Description

  The present invention relates to a camera.

  There is known a teleconverter that is mounted on a camera lens and combined with the focal length of the camera lens to increase the focal length. In addition, so-called electronic zoom is known in which a shooting screen is trimmed to take a pseudo zoom-up picture without changing the focal length of the zoom lens.

By the way, when a teleconverter is installed in front of the lens of the camera, when the angle of view of the lens of the camera body is large, the light incident on the lens is obstructed by the teleconverter, and the four corners of the shooting screen become black and "scratch" occurs. Sometimes. This phenomenon also occurs when a teleconverter is attached to the zoom lens and zoomed down to the wide side.
An object of the present invention is to prevent scramble when a teleconverter is attached to a lens of a camera.

(1) According to the first aspect of the present invention, in a camera capable of changing a focal length by mounting a teleconverter, warning means for issuing a warning to a user, and photometry for outputting a signal relating to the luminance of the subject image for each part of the photographing screen And when the brightness at the four corners of the shooting screen is not more than a predetermined value based on the luminance-related signal output by the photometry means with the teleconverter mounted, it is determined that the optical system has been damaged. and determining means, vignetting by said determining means and a controlling means for controlling to emit the warning means warns after it is determined that has been generated.
(2) The invention of claim 2 is a camera capable of changing a focal length by attaching a teleconverter, and in a state in which the photometric means for outputting a signal relating to the luminance of the subject image for each part of the photographing screen and the teleconverter are attached. , based on the signal related to output said luminance by the photometry means, when the luminance of the photographic image corners is less than a predetermined value, a determination unit and vignetting of the optical system has been generated, vignetting by said determining means There characterized in that it comprises a control means for controlling so as to generate non focal length of the eclipsed the combined focal length by teleconverter mounted after it is determined to have occurred.

According to the present invention, it is possible to automatically detect an optical system displacement due to the installation of a teleconverter, and to allow the photographer to recognize the occurrence of the displacement. Alternatively, it is possible to automatically detect the occurrence of the optical system breakage caused by the teleconverter mounting, and to prevent the breakage.

It is a figure which shows the structure of one embodiment. It is a perspective view of the camera of one embodiment. It is a figure which shows the change of the synthetic | combination focal distance by an optical zoom and an electronic zoom. It is a flowchart which shows the teleconverter mode control of one Embodiment. It is a figure for demonstrating the removal method of the injury by the magnification increase of an electronic zoom. It is a figure which shows the zoom-up by electronic zoom.

<< First Embodiment of the Invention >>
A first embodiment in which the present invention is applied to an electronic still camera with an optical zoom lens will be described. In addition, this invention is not limited to an electronic still camera, It can apply also to a silver salt film camera.

FIG. 1 is a diagram showing a configuration of an embodiment.
The CCD 1 is an image sensor that captures a subject image formed by a photographing lens, and outputs an analog signal corresponding to the brightness of the subject image for each pixel. The input circuit 2 performs processing such as gain adjustment on the analog image signal from the CCD 1 and then performs A / D conversion to perform image processing such as white balance adjustment, contour compensation, and gamma correction as original image data. Output. The compression / decompression circuit 3 compresses the original image data at a predetermined compression rate such as JPEG, and decompresses the compressed image data to the original image data.

  The buffer memory 4 is a memory for temporarily storing the original image data after photographing and the compressed image data after compression, and SRAM, VRAM, SDRAM or the like can be used. The memory card 5 is a removable recording medium, and a flash memory or the like can be used. The LCD 6 is a display panel for displaying information necessary for shooting such as a shooting mode, a continuous shooting mode, an image quality mode, a remaining battery level, and the number of shots. The monitor 7 is a liquid crystal display for displaying a photographed image. When the photographing mode is set, display image data is generated and displayed by the monitor image generation circuit 8 from the original image data photographed by the CCD 1, and when the reproduction mode is set, the memory is displayed. The compressed image data read from the card 5 is expanded by the compression / expansion circuit 3, and the display image data is generated and displayed by the monitor image generation circuit 8. The buzzer 9 is an alarm that is sounded at the time of abnormality or erroneous operation.

  The controller 11 is composed of a microcomputer and its peripheral components, and executes various camera operations and sequence control. In addition to the input circuit 2, compression / decompression circuit 3, buffer memory 4, memory card 5, LCD 6, monitor image generation circuit 8, and buzzer 9, the controller 11 includes a power switch 12, a release switch 13, a zoom-up ( T) switch 14, zoom down (W) switch 15, menu screen switch 16, lens position sensor 17, zoom lens driving stepping motor 18 and the like are connected.

  The zoom switches 14 and 15 are used not only for zooming the zoom lens but also for moving the cursor on the menu screen displayed on the monitor 7, switching between various modes, setting the number of shots, and the like. When the menu screen switch 16 is operated when the shooting mode is set, a shooting menu such as exposure compensation, photometry, and special shooting is displayed on the monitor 7, and the cursor is moved by the zoom switches 14 and 15 to select one. When the special shooting is selected from the shooting menu, a special shooting menu such as an electronic zoom, a tele-converter, and a wide converter is displayed, and the cursor is moved by the zoom switches 14 and 15 to select one. The lens position sensor 17 detects the optical zoom position of the zoom lens.

FIG. 2A is a perspective view of the camera according to the embodiment as viewed from the back.
The camera according to the embodiment is divided into a camera body 20 and a lens unit 21, and the lens unit 21 is connected to the camera body 20 so as to be rotatable about 90 degrees. The camera body 20 is provided with an LCD 6, a monitor 7, a shutter button 25, a select lever 26, a zoom button 27, a menu screen switch 16, and the like. The lens unit 21 is provided with a zoom lens 22, a strobe device 23, a finder window 24, and the like.

  When the select lever 26 is set to the “shooting” position, the power switch 12 is turned on, power is supplied to various circuits and devices of the camera, and the shooting mode is set. When the select lever 26 is set to the “playback” position, the power switch 12 is turned on, power is supplied to various circuits and devices of the camera, and the playback mode is set. When the T side of the zoom button 2 is pressed, the zoom up switch 14 is turned on, and when the W side is pressed, the zoom down switch 15 is turned on. The shutter button 25 is linked to the release switch 13.

FIG. 2B shows a state in which the teleconverter 31 is attached to the zoom lens 22.
When the teleconverter 31 is mounted in front of the lens 22, the combined focal length f becomes larger than the focal length in the case of the lens 22 alone, and a zoom-up photograph can be taken in which the subject is further enlarged.

Here, an electronic zoom mode and a teleconverter mode according to an embodiment will be described.
When the menu screen switch 16 and the zoom button 27 are operated to select special shooting from the shooting menu, and when electronic zoom is selected from the special shooting menu, the electronic zoom mode is set. In this electronic zoom mode, the photographic screen is trimmed and a pseudo zoom-up picture is taken with the optical zoom kept constant. Specifically, the image data in the center is captured from the imaging range of the CCD 1 and is enlarged or displayed or recorded in the size of a normal shooting screen.

  When the T side of the zoom button 27 is operated when the electronic zoom mode is set, the zoom lens 22 is driven to the telephoto side by the motor 18. If the T side of the zoom button 27 is kept pressed even after reaching the telephoto end (tele end), the central portion of the imaging screen is further zoomed up by electronic zoom. In this embodiment, if the magnification in the electronic zoom mode is variable and the T side of the zoom button 27 is kept pressed, the magnification gradually increases. Next, when the W side of the zoom button 27 is continuously pressed, the magnification gradually decreases. When the tele end of the optical zoom is reached, the electronic zoom is terminated and the mode is switched to the optical zoom, and when the W side of the zoom button 27 is continuously pressed. The zoom lens 22 is driven to the wide side by the motor 18.

FIG. 3 shows the combined focal length f of the zoom lens 22 and the teleconverter 31 by optical zoom and electronic zoom.
In the optical zoom that changes the focal length by driving the zoom lens 22, when the zoom lens 22 is driven from the wide end Wo to the tele end To, the focal length of the zoom lens 22 itself increases and the combined focal length f with the teleconverter 31 increases. Will also increase. As described above, when the zoom-up operation is further continued after the optical zoom position reaches the telephoto end To, zooming by electronic zoom is performed, and the composite focal length f increases in a pseudo manner while the optical zoom position remains constant.

  In electronic zoom with a silver film camera, the electronic zoom setting magnification at the time of shooting is recorded for each frame as magnetic information, and the center of the screen is trimmed according to the setting magnification at the time of printing in the laboratory, and normal shooting is performed. What is necessary is just to enlarge to the size of a screen.

  When the menu screen switch 16 and the zoom button 27 are operated to select special shooting from the shooting menu and further select a teleconverter from the special shooting menu, the teleconverter mode is set.

  As described above, when the teleconverter is attached to the zoom lens and the zoom lens is zoomed down to the wide side, the light incident on the zoom lens by the teleconverter at a specific composite focal length fk or less is disturbed, and the shooting screen is displayed. The four corners turn black. The combined focal length fk at which the blur occurs and the optical zoom position Pfk corresponding to the combined focal length fk can be obtained at the design stage of the teleconverter lens.

  Therefore, in this embodiment, when the teleconverter 31 is attached to the zoom lens 22 and the teleconverter mode is set by the menu screen switch 16 and the zoom button 27, the combined focal length f is less than the minimum combined focal length fk that causes the scramble. The optical zoom range is limited so that it does not occur. Since the optical zoom position can be detected by the lens position sensor 17, if the optical zoom position is on the wide side (Wo to Pfk) from the position Pfk at which the combined focal length fk is obtained, the zoom lens is forcibly moved to an indefinite position Pfk. 22 is driven. On the other hand, when the optical zoom position is in the range (Pfk to To) where the optical zoom position is not lost, the drive to the wide side of the zoom lens 22 is limited to the position Pfk.

FIG. 4 is a flowchart illustrating teleconverter mode control according to an embodiment.
The microcomputer of the controller 11 executes the telecon mode control shown in FIG. 4 when the teleconverter mode of the special shooting menu is set. In step 1, the optical zoom position of the zoom lens 22 is detected by the lens position sensor 17. In the subsequent step 2, the detected optical zoom position is compared with the position Pfk where the rash occurs, and if the detected position is on the wider side than the position Pfk, the process proceeds to step 3, and the detected position is moved to the tele side from the position Pfk. If yes, go to Step 5.

  If the optical zoom position is on the wide side of the position Pfk, a rash occurs. In step 3, the LCD 6 and the buzzer 9 warn the shooter of the rash. In subsequent step 4, the motor 18 is driven and controlled to forcibly move the zoom lens 22 to the optical zoom position Pfk. Thereafter, in step 5, the optical zoom range is limited to a range from the position Pfk to the tele end To so that the optical zoom position does not move to the wide side from the position Pfk.

  On the other hand, when the detection position is on the tele side with respect to the position Pfk, the process proceeds from step 2 to step 5, and the optical zoom range is moved from the position Pfk to the tele end To so that the optical zoom position does not move to the wide side with respect to the position Pfk. Limit to the range up to.

  As described above, when the teleconverter mode is set, if the optical zoom position of the zoom lens 22 is within the range where the zoom occurs, a warning is given, and the zoom lens 22 is forcibly driven to the position Pfk where the zoom does not occur. At the same time, the optical zoom range of the zoom lens 22 is limited to a range (Pfk to To) in which no breakage occurs. That is, when the teleconverter mode is set, the combined focal length f is set to be equal to or greater than the predetermined value fk, so that it is possible to prevent injury due to the teleconverter mounting.

  It is desirable that the position Pfk is set with a certain margin so as not to be distorted even if there are various disturbances.

<< Second Embodiment of the Invention >>
In the first embodiment described above, when the photographer attaches the teleconverter to the zoom lens and sets the teleconverter mode, an example is shown in which the optical zoom range is limited to a range that does not occur. In a range where degration occurs, erasure may be “excluded” by electronic zoom. If the optical zoom position is in a range that is not lost, the optical zoom range is limited so that it does not deviate from the range as in the first embodiment.

  As shown in FIG. 5, when the tele-converter mode is set and the optical zoom position is within the generation range (Pfk to Wo), the magnification by the electronic zoom is increased without changing the optical zoom position to simulate Thus, the combined focal length f is fk. For example, if the zoom lens position is P1 and the combined focal length is f1, the electronic zoom magnification m is increased until the combined focal length is apparently the minimum value fk. Increasing the electronic zoom magnification is to take out only the central part of the CCD image pickup screen and enlarge it to the size of the normal image pickup screen, as shown in FIG. Even if there are scratches at the four corners of the screen, the scraped parts will be “excluded”.

  Thus, when the teleconverter mode is set, if the optical zoom position of the zoom lens 22 is within the range where the displacement occurs, the magnification is increased by electronic zoom without changing the optical zoom position. Since the minimum combined focal length fk is set, it is possible to prevent injuries caused by the teleconverter without driving the lens.

<< Third Embodiment of the Invention >>
In the first embodiment, an electronic still camera with a zoom lens has been described as an example. However, the present invention is also applied to an electronic still camera with a single focus lens or a silver salt film camera with a single focus lens. can do. In this case, since there is no optical zoom, as described in the second embodiment, the electronic zoom is used to “eliminate” the injuries.

  When a teleconverter is installed in front of a single focus lens and the teleconverter mode is set, the combined focal length f of the single focus lens and the teleconverter cannot be changed, so it is simulated by increasing the magnification of the electronic zoom. Change the focal length. In this embodiment, the magnification of the electronic zoom is increased until the minimum combined focal length fk is obtained. It should be noted that the electronic zoom magnification may be set to 1 for a teleconverter in which no blur occurs.

  In this way, when the teleconverter mode is set for a camera with a single focus lens, the magnification is increased by electronic zoom up to the smallest combined focal length, so an electronic still camera with a single focus lens or a single focus In a silver salt film camera with a lens, it is possible to prevent the camera from being damaged by the teleconverter.

<< Fourth Embodiment of the Invention >>
In each of the embodiments described above, the teleconverter is attached to the camera lens and the teleconverter mode is manually set. However, a switch for detecting the attachment of the teleconverter is provided on the camera lens, and the teleconverter mode is automatically set. May be set. Specifically, a switch that operates when the teleconverter is installed is installed in the teleconverter mounting section of the camera lens, and when the switch is activated, the teleconverter mode is automatically set. The zoom is limited to an optical zoom range that is not possible, and in a camera with a single focus lens, as described above, the magnification is increased to the minimum composite focal length that is not lost by electronic zoom.

  In this way, a switch for detecting the installation of the teleconverter is provided on the lens of the camera, and when the installation of the teleconverter is detected by the switch, the optical zoom range is limited to an inevitable range or the electronic zoom is used. Since the magnification has been increased to the smallest possible composite focal length, there is no need to manually set the teleconverter mode each time the teleconverter is installed, and it is possible to avoid forgetting to set the teleconverter mode, while being hurt by installing the teleconverter. It can be prevented automatically.

<< Fifth Embodiment of the Invention >>
In the above-described embodiment, when the teleconverter mode is manually set or when the teleconverter mounting detection switch is activated, the example of implementing the countermeasure against the damage due to the teleconverter mounting is shown. It is also possible to automatically detect the occurrence of injury and take measures against injury.

  As described above, when the teleconverter is attached to the lens of the camera, the camera may be distorted and the four corners of the imaging screen may become black. In the electronic still camera, a signal corresponding to the subject brightness is output for each pixel of the CCD imaging screen, so when the brightness of all the pixels at the four corners of the imaging screen falls below a predetermined value as shown in FIG. As described above, the optical zoom range is limited to a non-destructible range, or the magnification is increased to a minimum combined focal length without an electronic zoom.

  In a silver halide film camera, a plurality of pixels are arranged on a shooting screen on which a subject image is formed by a lens, and a photometric element such as a CCD that performs photometry for each pixel is installed. When all the photometric values at the four corners of the shooting screen are reduced to a predetermined value or less, it may be determined that the injury due to the teleconverter has occurred, and the above-described measures against the injury may be implemented.

  In this way, if the pixel outputs at the four corners of the imaging screen are all reduced to a predetermined value or less, it is determined that the erasure has occurred, and the optical zoom range is limited to an inevitable range, or the electronic zoom is Since the magnification is increased up to a minimum composite focal length, it is possible to automatically detect the occurrence of camera lens displacement and to prevent it from occurring.

  In addition, according to the fifth embodiment, regardless of the type of teleconverter, any type of teleconverter lens can be mounted to automatically detect the occurrence of injury and prevent injury. . Furthermore, it can be applied not only to teleconverter lenses but also to all front conversion lenses that cause injuries, and automatically detects injuries regardless of the type of front conversion lens that is attached. It is possible to prevent the loss.

1; CCD, 6; LCD, 9; Buzzer, 11; Controller, 22; Zoom lens, 31; Teleconverter

Claims (6)

In cameras that can change the focal length by installing a teleconverter,
A warning means for issuing a warning to the user;
Photometric means for outputting a signal relating to the brightness of the subject image for each part of the shooting screen;
A determination unit that determines that the optical system has been damaged when the luminance at the four corners of the shooting screen is equal to or less than a predetermined value based on the signal relating to the luminance output by the photometry unit in a state in which the teleconverter is mounted ; ,
A camera comprising: control means for controlling the warning means to issue a warning after it has been determined by the determination means that an injury has occurred. In cameras that can change the focal length by installing a teleconverter,
Photometric means for outputting a signal relating to the brightness of the subject image for each part of the shooting screen;
A determination unit that determines that the optical system has been damaged when the luminance at the four corners of the shooting screen is equal to or less than a predetermined value based on the signal relating to the luminance output by the photometry unit in a state in which the teleconverter is mounted ; ,
And a control unit configured to control the combined focal length of the teleconverter so as to be a focal length that does not cause the erasure after it is determined that the erasure has occurred. The camera of claim 1,
The camera is characterized in that the control means controls the combined focal length by the teleconverter to be a predetermined value or more after the warning by the warning means is issued. The camera according to claim 1 or 2,
The camera is characterized in that the control means controls the combined focal length to be a predetermined value or more by optical zoom. The camera according to claim 1 or 2,
The camera is characterized in that the control means controls the combined focal length to be a predetermined value or more by electronic zoom. The camera according to claim 2 or 5,
The camera is characterized in that the control means controls the combined focal length so as to be a minimum combined focal length that does not cause a rash.

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