JP4734207B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus such as a digital camera or a digital video camera having display means for displaying a captured image, and more particularly to an imaging apparatus that captures an image in an area within a frame at the center of a screen while omitting a peripheral background.

  2. Description of the Related Art In recent years, digitalization of imaging devices such as digital cameras and digital video cameras has progressed, and technology for processing captured images digitally and recording and reproducing them has dramatically improved. Here, not only the entire photographed image is recorded, but also a recorded part of the photographed image is cut out. In a silver salt camera, trimming for printing only a predetermined range after photographing is widely known, and in a digital camera or the like, trimming can be performed using digital technology.

With the recent spread of the Internet, there are an increasing number of methods for using photographed images to upload and publish favorite photographed images on homepages (HP) or blogs (WEBLOG).
Shooting images uploaded to websites, blogs, etc. have the main role of visually supplementing text, so the space for writing text must not be impaired, and the aspect ratio and frame shape differ from conventional shooting images There is no problem even if it becomes. Also, there is no intention to print on photographic paper, and there is no need to consider the aspect ratio of the screen. And for images taken on websites, blogs, etc., a certain part of the photographed image is important, and in the periphery of the photographed image, extra items such as the background are photographed, making it suitable for uploading to websites, blogs, etc. The omission of unnecessary items such as backgrounds is preferred.

  Conventionally, trimming using a digital technique is a process in a personal computer or the like after photographing, and a digital camera is not designed in consideration of uploading a photographed image to a homepage or a blog. Therefore, for example, an image taken with a digital camera or the like is input (transferred) to a personal computer (PC), and a predetermined portion is cut out from the taken image on the PC and uploaded to a homepage or a blog.

In order to transfer a captured image from a digital camera to an external device such as a personal computer, for example, in Japanese Patent Laid-Open No. 2003-174610, a transfer button for transferring a captured image to an external device is provided on the digital camera, and the digital camera is connected to the personal computer. It is configured to automatically determine the communication means to be transferred and transfer the optimum image data corresponding to the determined communication means. According to this configuration, it is possible to automatically transfer image data corresponding to the determined transfer method of the communication means, and it is possible to omit a transfer method designation operation and an association operation of image data to be transferred.
JP 2003-174610 A

In order to cut out a predetermined portion from a photographed image taken with a digital camera and input to a personal computer and upload it to a home page or a blog, dedicated software is required. In addition, since the process is after shooting, it is difficult to obtain a satisfactory image because it cannot be redone even if a defect in the shot image is noticed at the time of trimming on a personal computer.
In the above Japanese Patent Laid-Open No. 2003-174610, only image data corresponding to the transfer method of the communication means is automatically transferred to a personal computer, and an image suitable for uploading to a homepage, a blog, or the like is taken. Not.

  In addition, along with the promotion of downsizing of digital cameras, lens aberrations, particularly distortion, occur in the peripheral part of the image, and the image is easily distorted. If the subject is not a landscape or a person, but a record jacket, book, flyer, pamphlet, menu, everyday accessory such as a handkerchief or accessory, or a flat plate with no thickness, such as a figure, a photographed image with noticeable distortion It is not suitable for uploading to homepages and blogs. Further, it is much more difficult to correct a distorted captured image as compared with image size change, color correction, brightness correction, and the like.

  Image distortion due to lens aberration or the like also occurs in the zoom lens. In the zoom lens, the distortion aberration also changes as the focal length changes. For this reason, the zoom lens is designed with a positive and negative balance of distortion aberration in the wide-angle range and the telephoto range so as not to hinder the shooting of landscapes and people. However, if all the focal lengths of the zoom lens are designed with distortion aberration suitable for a flat plate with no thickness such as a record jacket, the entire optical system becomes large, and it is difficult to reduce the size and weight, and it is expensive. This is undesirable.

  An object of the present invention is to provide an imaging apparatus capable of capturing an image suitable for uploading to a homepage, a blog, or the like by an image cutout function unique to digital technology.

According to the first aspect of the present invention, the imaging apparatus includes: an LED light source that irradiates a subject;
Obtained by a photographing lens for photographing a subject, an imaging means for capturing an image signal of the subject obtained through the photographing lens, an image display means for displaying an image obtained by the imaging means, and the imaging means Of the image signal obtained, the image signal image excluding the portion of the subject irradiated by the LED light source that does not have the effect of irradiation, or the image signal excluding the portion where the performance is deteriorated by the periphery of the photographing lens And a display control unit configured to synthesize a frame surrounding the image with the image of the image signal obtained by the imaging unit and display the image on the image display unit .

According to the second aspect of the present invention, an imaging apparatus is obtained by a photographing lens that photographs a subject, an imaging unit that captures an image signal of the subject obtained through the photographing lens, and the imaging unit. image display means for displaying an image signal, among the image signals obtained by the imaging means, a frame surrounding an image signal obtained through the peripheral portion of the photographing lens on the image signal obtained by said image pickup means synthesized and is constituted by a display control means for displaying on said image display means.

According to the present invention described in claim 3, the imaging device, obtained a photographic lens for photographing an object Utsushitai, imaging means for imaging an image signal of the subject obtained through the photographing lens, by the imaging means An image display means for displaying the image signal obtained, an image signal obtained by the imaging means, and an image signal in a frame surrounding the image signal obtained via the peripheral portion of the photographing lens are displayed on the image display means. In addition, it has a display control means for performing multi-display .

According to a fourth aspect of the present invention, the imaging apparatus further includes an LED light source that irradiates a subject, and the subject portion corresponding to the image signal in the frame is irradiated by the LED light source.
According to the fifth aspect of the present invention, the image signal obtained through the peripheral portion of the photographing lens has an aberration of the imaging lens, a decrease in the peripheral light amount of the photographing lens, and nonuniformity of irradiation from the LED light source. It has been affected by either.
According to the sixth aspect of the present invention, the imaging apparatus further includes recording means for recording the image signal after image processing, and the image signal obtained by adding the adjacent pixels of the imaging element in the frame. Is recorded in the recording means.

In the first aspect of the present invention, a frame is synthesized and displayed in the screen of the image display means, and if an image in the frame is captured , the background is not included and the brightness is substantially uniform. A captured image without distortion can be obtained.

According to the second aspect of the present invention, a frame is synthesized and displayed in the screen of the image display means, and if an image within this frame is captured, the captured image does not include any extraneous items such as the background and has no distortion. Is obtained.

According to the third aspect of the present invention, the relationship between the image to be photographed and the frame can be easily confirmed and judged, and if the image within the frame is photographed, the captured image does not include any extraneous objects such as the background and has no distortion. Is obtained.

In the present invention according to claim 4 , the photographing result can be predicted in advance by turning on the LED light source, and only the central portion having substantially the same brightness can be photographed. In addition, it is possible to take a picture while preventing a phenomenon that a part of the subject shines by reflection.
In the present invention described in claim 5 , the frame functions as a trimming frame, and by capturing an image within the frame, trimming after shooting is unnecessary.
In the present invention described in claim 6, since adjacent pixels are added together, the number of pixels is reduced, processing can be performed quickly, and a highly sensitive image can be obtained. Further, the S / N ratio can be improved by adding pixel signals of the same color.

  In the present invention, in the screen of the screen display means, a frame that surrounds the central region and changes in size according to the focal length of the zoom lens is displayed, and an image in this frame is captured and recorded. ing.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic block diagram of a main part of an imaging apparatus embodied as a digital camera.
As shown in FIG. 1, a digital camera (imaging device) 10 includes a zoom lens 12, a zoom control circuit 14, an imaging means 16, an AFE circuit (analog front end circuit) 18, an image processing circuit 20, an image determination circuit 22, and compression. A circuit 24, a recording control circuit 26, a recording means (memory) 28, an output means 29, a display control circuit 30, a display means 32, a central control circuit 34, a series of switches 36, a strobe (strobe means) 38, etc. Has been.

  For example, the image pickup means 16 is formed from an image pickup device such as a CCD or CMOS sensor, the display means 32 as an image display means is formed from a liquid crystal display (LCD), an organic EL display, or the like, and the central control circuit 34 is formed from a CPU, MPU, or the like. The The series of switches 36 includes a power switch (power SW) 36a, a release switch (release SW) 36b, a menu key 36c, an enter key (OK key) 36d, a zoom switch (zoom SW) 36e, a mode key 36f, and the like. Become. The menu key 36c is, for example, a cross key, which also serves as a left / right / up / down selection key, and the setting selected by the menu key is determined by a determination key (OK key) 36d. By switching the switches 36c to 36f and the like, shooting / playback mode switching, shooting mode switching, and the like are also performed.

  The zoom lens 12 is changed to a predetermined zoom position under the control of the zoom control circuit 14, and an image from the subject 40 is formed on the image pickup means 16 such as a CCD through the zoom lens and subjected to photoelectric conversion, and AD. Digitized by an AFE circuit 18 including a conversion circuit. The digitized image signal is input to the image processing circuit 20, where the image processing circuit corrects the color, gradation, sharpness, and the like of the image signal, and compression processing is performed in a subsequent circuit during photographing.

  The AFE circuit 18 not only digitizes the analog signal from the image pickup means (CCD) 16 but also has a function of selecting a signal output from the CCD, and limited image data from a part of the light receiving surface of the CCD. To extract. If image data extracted from this limited predetermined range is recorded, the same effect as trimming can be obtained. A device for capturing a trimmed image (trimmed image) is very effective when it is not desired to record everything captured on the light receiving surface of the CCD 16.

  In the CCD 16 having many pixels, the S / N ratio can be improved by adding pixel signals of the same color, and this addition processing is also performed by the AFE circuit 18. When the addition process is performed, the number of pixels that are effectively used decreases. However, generally, in a personal computer (PC) monitor or the like, the monitor capability is limited, and an excessive number of pixels does not make any sense. For this reason, for example, when a photographed image of the digital camera 10 is used for a homepage, a blog, or the like, the image size may be smaller than that premised on printing, and a reduction in the number of pixels is not a problem. On the other hand, if the number of pixels is too large, the processing takes time, which is disadvantageous.

The image processing circuit 20 has a resizing circuit 20a, and the image signal from the CCD 16 is resized to a size displayed on the display means 32 such as a liquid crystal display (LCD) by confirming the composition and timing of the photographing prior to photographing. The image is processed by the means, controlled by the display control circuit (display control means) 30, and displayed on the LCD 32 in real time as a through moving image (live view image).
The display control circuit 30 has a frame display circuit 30a, and the frame display circuit displays a frame (trimming frame) for using only an image in a predetermined area on the LCD 32 in a superimposed manner (multi-display). To do. As will be described later, this frame indicates a central area of the screen in consideration of screen distortion. In addition, it is preferable that the user can adjust the shape of the frame.

  While viewing the images (through moving images and live view images) displayed on the LCD 32, the user determines the composition and timing at the time of shooting with reference to the frame (trimming frame) and performs the shooting operation. Since the display on the liquid crystal display 32 is not a high-definition display, the display image does not become rough even if a predetermined area in the frame is enlarged during trimming. Therefore, the image may be enlarged and displayed.

  In addition to the through moving image before photographing, on the LCD 32, the image signal recorded in the memory 28 is also expanded and reproduced / displayed by the image processing circuit 20. In addition, camera operation by the menu key 30c or the like or various functions and mode settings of the camera are also displayed on the LCD 32.

  The image determination circuit 22 determines the characteristics of the image data input from the CCD 16 using the signal from the image processing circuit 20.

  The compression circuit 24 includes a still image compression unit 24a such as a JPEG core unit, MPEG4, H.264, and the like. And a moving image compression unit 24b including a compression core unit such as H.264. The signal output from the image processing circuit 20 is compressed by the compression circuit and is recorded via the recording control circuit 26. (Memory) 28.

  The image data recorded in the memory 28 is transferred to an external device 42 such as a personal computer via the output means 29 and uploaded to a homepage, a blog or the like. In the present invention, the image data premised on uploading to a home page or blog is devised so that a predetermined effect can be obtained at the time of uploading by performing a shooting method corresponding to upload from the time of shooting. Further, from the output of the image determination circuit 22, it is determined whether or not auxiliary light of auxiliary light emitting means such as a strobe 38 or an LED (light emitting diode) light source described later should be irradiated, and corresponding control is performed.

  Components such as the zoom control circuit 14, the AFE circuit 18, the image processing circuit 20, the image determination circuit 22, the compression circuit 24, the recording control circuit 26, and the display control circuit 30 are centrally controlled by a central control circuit (CPU) 34. The For example, the CPU 34 determines a user operation from the display on the LCD 32 and the input status of the switches 36a to 36f, and controls the sequence of the digital camera 10 from the determination result. When the CPU 34 detects and executes the operation of the corresponding switches such as the menu key 36c, the determination key 36d, and the mode key 36f, the photographing mode (blog mode) for creating a trimmed image, which is a feature of the present invention, can be switched. In addition, the CPU 34 monitors the zooming position by switching the focal length of the zoom lens 12 via the zoom control circuit 14.

  In zoom shooting, if a zoom control button is provided and the zoom lens 12 is controlled by the zoom control circuit 14 and the subject cannot be enlarged (optical zoom) by the zoom lens, the CPU 34 has an area for taking out the captured image from the CCD 16. A digital zoom is generally employed in which limited control is executed by the AFE circuit 18 and the extracted partial images are displayed and recorded as full images to extend the zoom. Further, the strobe 38 emits light according to the situation, and the subject is irradiated with auxiliary light to prevent lack of brightness and uneven brightness, and shooting is performed.

FIGS. 2A to 2F are schematic diagrams of a shooting simulation performed by displaying image information on a liquid crystal display (LCD), and FIGS. 3A and 3B are shot images transferred to a personal computer. Indicates.
A situation in which a record jacket placed on the desk 41 is photographed as the subject 40 will be described with reference to FIG. For example, if the vertical and horizontal relationship between the shooting range 32a of the camera and the record jacket (subject) 40 is not set correctly, an inclined image 40 as shown in FIG. Is displayed on the monitor 42a of the personal computer.

  When a tilted image 40 as shown in FIG. 3A is taken, when uploaded to a homepage or blog, the relationship with the text displayed at the same time is not beautiful, the balance is also poor, and there is a space for writing the text. Less. Therefore, as shown by an arrow in FIG. 2B, the user moves the record jacket 40 above the shooting range 32a to try to align the upper edge of the shooting range with the upper edge of the record. However, normally, the performance of the peripheral portion of the lens deteriorates from the central portion (near the optical axis) due to aberrations and the like, and distortion occurs in the peripheral portion. Therefore, the upper end 40a of the record jacket 40 in the peripheral portion of the lens is distorted. It becomes a deformed image.

If there is only room for selection of either the slanted screen of FIG. 2A or the distorted screen of FIG. 2B, the user will feel stress.
Therefore, in the embodiment, as shown in FIG. 2C, a frame (trimming frame) 32b that does not cause an inclination is set at a location that is not affected by the aberration near the center of the screen, and is limited within this frame. It is possible to extract only the images that have been recorded. By making the frame 32b variable within the range not affected by the aberration of the lens in the screen, it is not necessary to photograph the desk 41 on which the record jacket (subject) 40 is placed. The trimming process is omitted. By using the frame 32b, as shown in FIG. 3 (B), the image record sleeves 40 of the correct relationship is displayed on the monitor 42a of the personal computer.

As shown in FIG. 2D, the photographing part in the frame 32b is displayed in the center of the screen of the LCD 32 with the record jacket 40 as the subject having the least lens aberration. However, as shown in FIG. 2E, it may be enlarged and displayed over the entire display range of the LCD, and as shown in FIG. 2F, both the monitor range 32c by the CCD 16 and the image in the frame 32b are displayed on the LCD 32. Multiple display may be used.
In the enlarged display of FIG. 2 (E), since it is displayed large over the entire screen, it can be easily confirmed whether the focus is correct, the brightness is uniform, or there is no color unevenness on the whole.
In the multi-display in FIG. 2F, the relationship between what the digital camera 10 is about to shoot and the frame 32b can be easily confirmed and judged. In addition, it is easy to understand the switching state in shooting performed while switching the variable frame 32b, and it can be easily understood that it is a multi-display shooting mode.

  The CPU 34 monitors the zooming position by switching the focal length of the zoom lens 12 via the zoom control circuit 14. Since the influence of lens aberration varies depending on the zoom position of the zoom lens 12, the relationship between the frame range of the focal length position with the least aberration and the zoom position is stored in advance in a flash ROM (not shown), and the CPU 34 flashes. The frame display circuit 30a is controlled according to the zooming position while reading the ROM. The range and size of the frame 32b may be selectable by the user from several patterns, or may be continuously variable. In this case, a dedicated switch for selecting the frame 32b or a dedicated switch for changing the frame may be provided, or a frame may be selected by using a switch of another function, for example, the menu key 36c and the enter key 36d. Possible or variable.

FIG. 4 shows a flowchart of a control sequence of the digital camera 10 configured as described above.
First, in S1, an output signal (image information) from the CCD 12 is displayed on the LCD 32 in real time as a through moving image (live view image). The user confirms the subject 40 from the display image on the LCD 32, determines the shooting timing and composition, and performs the shooting operation. It is determined whether or not shooting is performed in S2, and if shooting is not performed, the process branches to S9 to determine whether or not the playback mode is set. If the playback mode is in S9, the LCD 32 is switched to playback display in S21, and the image data in the memory 28 is played back and displayed.

In S22, it is determined whether or not to transfer the reproduced and displayed image data to an external personal computer 42 or the like. When transferring, the process returns to S9 after transferring the data in S23, and returns to S9 from S22 if not transferred.
If the playback mode is not set in S9, it is determined in S10 that the power supply is turned off. If the power supply 0FF is operated, the power supply is turned off and the process ends. Zoom control is performed. The zoom control is performed, for example, under the control of the zoom control circuit 14 by the user operating the zoom SW 36e.

  As shown in FIG. 2C, the setting of the shooting mode (blog mode) that limits the shooting range is determined in S12, and if it is the blog mode, the display control means moves to the periphery of the screen according to the zoom position of the zoom lens 12 in S13. In comparison, a frame (trimming frame) 32b that surrounds the center area of the screen with relatively little distortion is displayed on the LCD 32 by being combined (superimposed) with the subject image. The frame shapes to be displayed are, for example, as shown in FIGS. 2D to 2F, and these frame shapes are switched by the user (S14), and the display mode corresponding to the change in the frame shape is changed. It is switched (S15). Note that the frame shape in FIG. 2D is initially set.

If the enlarged display is determined in S16 and there is an enlarged display operation, the enlarged display as shown in FIG. 2E is made in S17 and the process returns to S1. If there is no enlargement display operation, then in S18, the multi-display operation is determined in S18, and if there is a multi-display operation, the multi-display as shown in FIG. 2F is made in S19 and the process returns to S1. If there is no enlarged display or multi-display operation, the process returns to S1 with the default frame shape.
If shooting in the blog mode is not performed in S12, the process branches to S20 to cancel the blog setting, and then returns to S1.
As described above, when the blog mode is set, the display on the LCD 32 is devised, and the user can set a favorite display.

While looking at the devised display screen of the LCD 32, shooting is performed in S2, and shooting in the blog mode is determined in S3. Record jackets, books, handkerchiefs and accessories posted on homepages and blogs, thin flat objects such as figures, figures, etc., tend to shine partly by reflecting the light from the strobe 38. . Therefore, in the blog mode, shooting is performed using the light emission prohibiting unit that does not cause the strobe 38 to emit light (S4), and only the shooting information within the frame is used without using the outside (peripheral part) of the frame 32b set in S14. Is taken out by the image processing circuit 20 (S5), and the result is compressed and recorded in the memory 28 (S7, S8). If the blog mode is not set in S3, the process branches to S6 and normal shooting without using the frame 32b, for example, automatic shooting is performed (S6), and the shot image data is compressed and recorded (S7, S8).
As described above, according to this embodiment, by selecting the blog mode, it is possible to shoot without the peripheral portion (outside frame portion) under the preferred frame shape, so that it does not include extraneous items such as the background, and is distorted. A photographed image with little can be obtained. In other words, images suitable for uploading homepages and blogs can be taken.

Figure 5 is a cross section of the digital camera as an image pickup device cut along a section including a zoom lens, shows a graph showing the relationship between the radiation range of the angle of view and the LED light source, FIG. 6, FIG. 7 (A) ( B) is a schematic diagram of a recording simulation of a record jacket on a desk in another embodiment (embodiment 2) of the present invention.
The strobe light from the strobe 38 is only emitted instantaneously at the time of shooting, and it is difficult to determine what kind of image is obtained. Therefore, in the second embodiment, an LED (light emitting diode) light source (LED light source) 38 ′ that projects light onto the subject 40 is provided in the digital camera 10 together with the strobe 38 to enable photographing under the LED light source. . The light from the LED light source 38 ′ can be lit not only for a moment like the strobe 38, but also always lit, so that the photographing result can be predicted in advance. Further, it is possible to enjoy photographing while preventing a phenomenon in which a part of the subject 40 shines by reflection.

Unlike the strong light emission of the strobe 38, the light from the LED light source 38 'is weak and sufficient brightness cannot be obtained unless it is condensed, and its radiation range is from the angle of view of the zoom lens 12 as a photographing lens. Narrow range. However, as shown in FIG. 6, in shooting the record jacket 40 or the like, it is not necessary to allow light to reach the background of the record jacket, and only a predetermined range including the record jacket needs to be irradiated. That is, in the blog mode, the LED light source can be used effectively without any trouble even with the light from the LED light source 38 ' .

  Since it is meaningless to display other than the range irradiated by the LED light source 38 ', instead of displaying on the LCD 32 including the periphery of the record jacket 40 as shown in FIG. 7A, the display shown in FIG. It is easy to understand if only the central record jacket is displayed. Further, if an unnecessary part (peripheral part) is deleted and only a necessary part (center part) is enlarged, the display becomes easy to see. Although it is difficult for the light emitted from the LED light source 38 'to be uniform, only the substantially uniform central portion is taken out, so that it is possible to photograph with uniform brightness. Subtle brightness unevenness can be corrected by making it uniform by image processing.

  FIG. 8 is a flowchart illustrating a control sequence of the digital camera 10 according to the second embodiment. In the blog mode after S12, the flowchart of the second embodiment is substantially the same as the flowchart of FIG. The difference from the flowchart of FIG. 4 (Example 1) will be described. If the blog mode is determined in S12, the brightness of the subject 40 is determined from the output of the CCD in S25. If the subject 40 is dark, the LED light source 38 'is irradiated as auxiliary light emitting means in S26, and only the irradiated portion is displayed as a frame (S27), and image processing for correcting the intensity distribution of the light emission pattern of the LED light source is performed. (S28) and displayed on the LCD 32. When the outputs of adjacent pixels of the same color of the CCD 16 are added, the sensitivity is improved and the scene becomes sensitive to a dark scene or LED light. Therefore, the pixel addition is performed in S29, and then the process returns to S1 for photographing.

  Since the irradiation position of the LED light source 38 ′ in the monitor range changes with respect to the subject depending on the distance to the subject 40, the position and size of the frame display on the display screen may be changed in conjunction with the focusing result. In addition, since the size of the irradiation area of the LED light source 38 ′ varies depending on the zoom position, the frame display is also changed corresponding to the zoom position.

  If it is determined in S25 that the subject 40 is not dark (bright), the process branches to S30 and only the frame display is performed, and the central portion that is not easily affected by the aberration is specified as in the first embodiment. In step S29, the pixels are added to increase the sensitivity, and then the process returns to step S1 to perform shooting.

  Thus, if the LED light source 38 'is used as auxiliary light, an image illuminated with appropriate brightness can be taken even in a dark scene. Especially for everyday items such as record jackets, books, handkerchiefs and accessories, and flat plates with no thickness such as figures, the atmosphere tends to change due to reflection. However, if the LED light source 38 'can be used for continuous irradiation as in the second embodiment, the user can take a picture while confirming the illumination state of the particular item (subject) on the LCD 32 in real time, which is sufficiently satisfactory. An image is obtained.

  When the irradiation range of the LED 38 ′ is widened, the light density is reduced and darkened. However, by irradiating only a predetermined range corresponding to a range free of aberration as in the second embodiment (a central portion excluding the peripheral portion), a wasteful amount of light is not lost in the background of the peripheral portion. The amount of light can be secured, and a distortion-free screen can be photographed with substantially uniform illumination.

If this idea is applied, a digital camera that takes measures against a drop in the amount of light around the lens itself can be considered. That is, in the second embodiment, a countermeasure is taken against the non-uniformity of the irradiation of the LED light source 38 ′, but the amount of light decreases when the lens itself moves away from the optical axis. It is easy for users to be unhappy. In addition, in general snapshot shooting with a person as the main subject, various subjects enter the screen, so the uneven brightness is not too much of a concern. In contrast, shooting with only a specific subject is not. We are worried about uniform brightness. Therefore, it is also effective to apply the idea of the present invention and take out a place where the light intensity drop is a predetermined value or less and display the frame.
In consideration of such a concept, the control in the step of the flowchart S13 in FIG. 4 may be performed.
In the first and second embodiments, the description has been made on the assumption that the zoom lens is used. However, the above technique can be similarly applied to a single focus lens.

Another embodiment (Example 3) of the present invention will be described in detail with reference to FIGS. In the third embodiment, it is possible to shoot with less distortion by utilizing the fact that the manner of aberration changes depending on the zoom position. In other words, in general, in designing a zoom lens, it is difficult to design without aberration in all focal length regions. At the end on the wide angle side (W side) and the telephoto side (T side), a barrel type or a pincushion type is used. Aberrations occur and are designed to cancel them in the middle region.
FIGS. 9A, 9B, and 9C are conceptual diagrams of distortion on the wide-angle side, focal length S (one point between the wide-angle side and the telephoto side), and distortion on the telephoto side. As shown in FIGS. 9A and 9C, a barrel distortion occurs with respect to a predetermined image (indicated by a dotted line) on the wide-angle side, and a pincushion distortion occurs on the telephoto side. If the focal length S shown in FIG. 9B for canceling out the aberration is the zoom distance S, a record jacket or the like can be photographed without aberration. A case where photographing is performed with the focal length S that cancels aberration as the zoom distance S will be described below.

  FIG. 10 shows a schematic diagram of a shooting simulation of a record jacket on a desk. As shown in FIG. 10, when the record jacket 20 on the desk 41 is photographed using the zoom position S, the contour of the record jacket may be photographed according to the frame (trimming frame) 32a. If the background around the subject is not desired to be photographed, the frame 32a may be displayed in a multi-display (see FIG. 2F), and only the part excluding the background may be taken out and photographed. be equivalent to.

FIG. 11 shows a flowchart of a control sequence of the digital camera 10 in the third embodiment. The flowchart of FIG. 11 is different from the flowchart of FIG. 4 in that the monitor display unit flowchart in the blog mode (S31 to S33) and the step S36 are added for normal zoom control. Is equivalent to the flowchart of FIG.
That is, if the blog mode is set in S12, the zoom lens 12 is automatically set to a predetermined zoom position corresponding to the focal length S in FIG. 9B as zoom control means (S31), and the frame 32a is set. Select and display (S 32 ). According to this method, a useless trimming step can be omitted. In addition, it is possible to avoid recording unnecessary portions (peripheral portions having aberrations) and to have a margin in the memory, and a large number of images can be recorded.
In addition, since the number of pixels more than necessary is not necessary for posting on a homepage or blog, the pixel is added (S33) to improve sensitivity, and then the process returns to S1 to shoot, so even if the shutter speed is increased, camera shake does not occur. No photography is possible.

  As described above, in the third embodiment, it is possible to easily shoot an image having an accurate vertical and horizontal alignment in accordance with a screen on a homepage or a blog with a focal length S without lens distortion.

12A, 12B, and 12C are cross-sectional views of the lens at the wide-angle end, the intermediate position, and the telephoto end in an example of the zoom lens, and FIGS. 13A, 13B, and 13C are zoom lenses shown in FIG. FIG. 5A shows aberration diagrams of distortion at the wide-angle end, intermediate position, and telephoto end.
As shown in FIGS. 13A, 13B, and 13C, if the focal length within 1% of the distortion is set as the zoom distance S, an image with no noticeable aberration can be taken in a wide range.

The aspherical shape is expressed by the following equation, where x is an optical axis with the traveling direction of light as positive and y is in a direction orthogonal to the optical axis. Here, r is a paraxial radius of curvature, K is a conical coefficient, and A ₄ , A ₆ , A ₈ and A ₁₀ are 4th, 6th, 8th and 10th order aspherical coefficients, respectively.
^{x = (y 2 / r)} / [1+ {1- (K + 1) (y / r) 2} 1/2] + A 4 y 4 + A 6 y 6 + A 8 y 8 + A 10 y 10

Various coefficients of the lenses constituting the zoom lens 12 are as follows. Here, r is the radius of curvature of the lens surface, D is the distance between the lens surfaces, nd is the refractive index of the d-line of the lens, νd is the Abbe number of the lens, f is the focal length of the entire system, and _FNO is the F number. is there.
Surface number r D nd νd
1 -11.535 ASP 0.92 1.52542 55.78
2 44.496 ASP D2
3 5.974 ASP 1.43 1.80610 40.92
4 -9.711 0.01 1.56384 60.67
5 -9.711 0.95 1.51633 64.14
6 -21.069 0.10
7 Aperture 0.20
8 14.326 1.13 1.78800 47.37
9 -14.326 0.01 1.56384 60.67
10 -14.326 0.50 1.80518 25.42
11 3.669 D11
12 61.202 2.31 1.52542 55.78
13 -8.645 ASP D13
14 -41.658 ASP 1.00 1.52542 55.78
15 -14.560 0.13
16 ∞ 0.40 1.54771 62.84
17 ∞ 0.20
18 ∞ 0.50 1.51633 64.14
19 ∞ 0.42

Aspheric coefficient Surface number r K
1 -11.535 -4.739
A ₄ A ₆ A ₈ A ₁₀
-2.42892e-05 5.93100e-06 1.06044e-07 -7.34218e-09
Surface number r K
2 44.496 -286.654
A ₄ A ₆ A ₈ A ₁₀
4.03482e-04 -9.96697e-06 1.21655e-06 -3.75453e-08
Surface number r K
3 5.974 -0.361
A ₄ A ₆
-7.83563e-04 -0.353928e-05
Surface number r K
13 -8.645 -5.933
A ₄ A ₆ A ₈ A ₁₀
-8.36717e-04 -3.42841e-05 2.37781e-06 -4.11212e-08
Surface number r K
14 -41.658 -418.964
A ₄ A ₆ A ₈
-2.41451e-03 -1.13925e-05 2.20868e-06

Zoom data f 6.51 8.32 18.53
F _NO 3.17 3.6 5.90
2ω 57.9 ° 46.8 ° 22.0 °
D2 12.75 9.20 1.50
D11 2.45 4.10 12.37
D13 2.44 2.44 2.68

In the intermediate focal length (intermediate focal length S), a focal length with a small distortion is set. In particular, in the embodiment, the intermediate focal length S (8. 32mm) makes it easy to photograph a subject such as a record jacket without leaving a distance.
Note that the general intermediate focal length is conventionally expressed by the following conditional expression, which is 11.00 mm in the embodiment.
General intermediate focal length = (wide-angle end focal length x telephoto end focal length) ^0.5
When the distortion is reduced by image processing in the camera, the magnitude of the distortion may be the size after image processing.

The above-described embodiments are for explaining the present invention, and are not intended to limit the present invention. All modifications, alterations, etc. within the technical scope of the present invention are included in the present invention. Needless to say.
For example, in the embodiments, a digital camera is given as a specific example, but the imaging device that is the subject of the present invention is not limited to a digital camera. For example, a digital video camera as well as a mobile phone having a digital camera function, Mobile devices with cameras such as notebook computers are also included in the imaging device.

  As described above, according to the present invention, an image suitable for uploading to a homepage, a blog, or the like can be easily taken by an image cutout function unique to digital technology.

  The present invention can be widely applied to an imaging apparatus such as a digital camera having an image display means such as a liquid crystal display.

1 is a schematic block diagram of a main part of an imaging apparatus according to an embodiment of the present invention embodied as a digital camera. (A)-(F) show the schematic diagram of the imaging | photography simulation made by displaying image information on a liquid crystal display. Shows the shot image transferred to the computer. 2 is a flowchart of a control sequence of the digital camera in Embodiment 1. The imaging device cut along the cross section including the zoom lens is also a cross section of the digital camera, and shows a relationship diagram between the angle of view and the radiation range of the LED light source. FIG. 6 shows a schematic diagram of a recording simulation of a record jacket on a desk in Example 2. FIG. (A) and (B) are schematic diagrams of a shooting simulation of a record jacket on a desk in Example 2. FIG. 9 is a flowchart of a control sequence of a digital camera in Embodiment 3. A conceptual diagram of distortion on the wide angle side, focal length S, and telephoto side is shown. FIG. 9 shows a schematic diagram of a recording simulation of a record jacket on a desk in Example 3. FIG. 9 is a flowchart of a control sequence of a digital camera in Embodiment 3. (A), (B), and (C) are sectional views of the lens at the wide-angle end, the intermediate position, and the telephoto end in an example of the zoom lens. (A), (B), and (C) are aberration diagrams of distortion at the wide-angle end, the intermediate position, and the telephoto end of the zoom lens shown in FIG.

Explanation of symbols

10 Digital camera (imaging device)
12 Zoom lens 14 Zoom control circuit (zoom control means)
16 Image sensor (CCD)
18 AFE circuit (analog front-end circuit)
20 Image processing circuit (image signal extracting means)
22 Image determination circuit 28 Recording means (memory)
30 Display control circuit (display control means)
30a Frame display circuit 32 Liquid crystal display (LCD; image display means)
32a Camera shooting range 32b Frame (trimming frame)
34 CPU (Central Control Circuit)
38 Strobe (auxiliary light emission means)
38 'LED light source (auxiliary light emitting means)
40 Subject 41 Desk 42 Personal computer 42a Personal computer monitor

Claims (1)

A zoom lens to shoot the subject,
Imaging means for imaging the image signal of the subject obtained through the zoom lens;
A switching means capable of switching between normal shooting and a shooting mode for creating a trimmed image ;
Zoom control means for setting the focal length of the zoom lens;
Display means for displaying an image obtained by the imaging means on a display screen;
An image displayed on Symbol display screen, display control means capable of superimposing the frame indicating the central region of the display screen,
When the switching means is switched to a shooting mode for creating the trimmed image, the zoom control means controls the setting of the focal length of the zoom lens to a focal length that cancels out distortion aberration between the wide-angle end and the telephoto end. A central control circuit that superimposes the frame on the display screen by the display control means and records an image in the frame;
An imaging device comprising:

Images