JP2008158027A - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption in finder display in an imaging device which displays various kinds of information within finder field. <P>SOLUTION: The imaging device equipped with a plurality of display units 33 and 47 which display information within the finder field selects either of the first display unit 33 which displays predetermined information and the second display unit 47 that is a display unit to display information physically unrelated to the first display unit 33 and which displays at least a part of the predetermined information in common according to the detected value of subject luminance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photographing apparatus that displays various types of information within a viewfinder field.

The subject image formed on the focusing screen by the photographing lens is guided to the finder eyepiece through a pentaprism and a plurality of prisms having two optical surfaces with different angles with respect to the photographing optical axis, and by an LED light source. The focus area mark displayed by the illuminated transmissive liquid crystal is reflected by the two optical surfaces of the prism and guided to the eyepiece, so that the subject image and the focus area mark are superimposed and displayed in the same viewfinder field. A finder display device that performs pause display is known (see, for example, Patent Document 1).
Also, in a viewfinder device that displays information by overlaying a diffusing liquid crystal display between the pentaprism and the screen and overlaying the subject image, if the subject image is dark, the illuminating device covers the liquid crystal layer from both sides of the diffusing liquid crystal. There is known a finder device that illuminates so that a display segment looks bright even in a dark scene such as a night view (see, for example, Patent Document 2).

Prior art documents related to the invention of this application include the following.
JP-A-11-237659, JP 2001-305539 A

  However, in the finder display device of Patent Document 1 described above, the visibility is good, but the higher the subject brightness, the more current that flows to the LED light source must be illuminated and the brighter the illumination, so the battery power consumption increases. There is. On the other hand, the above-described finder device of Patent Document 2 uses a diffusion-type liquid crystal (displays a display segment by diffusing liquid crystal), and illuminates the diffusion portion when the subject brightness is low. Compared with the one using LED light as described in Reference 1, there is a problem that the display brightness is not so much increased and the visibility is not expected.

  The present invention is a photographing apparatus having a plurality of display means for displaying information in the viewfinder field, wherein the first display means for displaying predetermined information and the first display means are physically independent. One of display means for displaying information and second display means for commonly displaying at least a part of the predetermined information is selected according to the detected value of the subject luminance.

  According to the present invention, it is possible to select a finder display unit that does not reduce the visibility according to the subject luminance and display information. In addition, since the display means can be selected in this way, the battery power is not consumed more than necessary when performing the finder display.

  An embodiment in which the finder display device of the present invention is mounted on a single-lens reflex digital camera will be described. The finder display device of the present invention is not limited to a single-lens reflex digital camera, and can be applied to all types of imaging devices that display various types of information in a finder field of view.

  FIG. 1 shows the configuration of a single-lens reflex digital camera according to one embodiment, and FIG. 2 shows a cross-sectional view of the camera according to one embodiment. In FIGS. 1 and 2, the illustration of devices and circuits not directly related to the present invention is omitted. The microcomputer 1 includes peripheral components such as a CPU and a memory, and executes various calculations of the camera and various sequence controls, and executes a control program described later to execute finder display control. The camera of one embodiment shows an example of an interchangeable lens type, and the microcomputer 1 inputs lens information such as an open aperture value, a focal length, and an exit pupil from a lens control device (not shown) built in the interchangeable lens.

  The photometry circuit 2 measures the subject luminance by dividing the subject luminance into a plurality of regions by the photometry sensor 3. The exposure control circuit 4 calculates the shutter speed and the aperture value based on the subject brightness detected by the photometry circuit 2 and the preset imaging sensitivity, and controls the shutter control unit 5 and the aperture control unit 6. The shutter control unit 5 controls the shutter 7 so that the shutter speed of the calculation result is obtained, and the aperture control unit 6 controls the aperture 8 so that the aperture value of the calculation result is obtained.

  The focus detection circuit 11 receives a signal indicating the focus adjustment state of the interchangeable lens 10 from a focus detection sensor 12 disposed at the bottom of the camera body, and detects the defocus amount of the interchangeable lens 10 by a phase difference detection method. The lens drive circuit 13 drives a focusing lens (not shown) of the interchangeable lens 10 according to the defocus amount of the detection result, and performs focus adjustment. In this embodiment, an example in which a motor for driving the focusing lens is built in the interchangeable lens 10 is shown, but it may be installed in the camera body. The mode setting circuit 14 sets various shooting modes such as exposure, autofocus, and image. The setting operation member 15 is an operation member for performing a setting operation of the camera. The half-push switch SW1 is closed by a first stroke of a release button (not shown), and is closed by a second stroke deeper than the first stroke of the release button. And a fully-pressing switch SW2 is included.

  The temperature sensor 16 is disposed in the vicinity of the image sensor 17 and monitors the temperature of the image sensor 17. The image sensor 17 is composed of a CCD, a CMOS, or the like, and captures a subject image formed by the interchangeable lens 10 and outputs a subject image signal. The A / D conversion circuit 18 A / D converts the subject image signal output from the image sensor 17. The timing circuit 19 controls the imaging timing of the imaging device 17 and the A / D conversion timing of the A / D conversion circuit 18. The image processing control circuit 20 performs image processing such as white balance adjustment, sharpness adjustment, gamma correction, and gradation adjustment on the subject image data, and performs interpolation processing on the subject image data of each color. Note that the image sensor 17, the timing circuit 19, the A / D conversion circuit 18, the image processing control circuit 20, and the temperature sensor 16 are mounted on an image pickup substrate 21 disposed behind the image sensor 17.

  The SDRAM 22 temporarily stores the corrected subject image data, and the image recording medium 23 records the subject image data and shooting data together in various file formats. As the image recording medium 23, a compact flash, an SD card, smart media, or the like can be used. The rear liquid crystal control circuit 24 controls the rear liquid crystal monitor 25 provided on the rear surface of the camera body to display images and various information. The in-viewfinder display control circuit 26 controls the in-viewfinder transmissive liquid crystal display 27 and its backlight 28, and as shown in FIG. 3, below the viewfinder screen 29 viewed from the viewfinder eyepiece window (FIG. 3 and the drawings to be described later). 4. Various shooting information such as the shooting mode, the number of shots, the shutter speed, and the aperture value are displayed in A) of FIG.

  The first superimpose display control circuit 30 controls the first superimpose diffusion type liquid crystal display 33 disposed between the screen 31 of the finder optical system and the penta roof prism 32, and the interchangeable lens 10 controls the first superimpose display control circuit 30. The 21 focus area marks 34 shown in FIGS. 3 and 4 and the crop high-speed reference area 35 shown in FIG. 4 are superimposed on the subject image formed in FIG. The focus area mark 34 is an area for detecting the focus adjustment state of the interchangeable lens 10, and the crop high-speed reference area 35 indicates a cut-out range of the screen at the time of high-speed continuous shooting. In the first superimpose display by the first superimpose diffusion type liquid crystal display 33, the subject light is diffused by the display segment of the diffusion type liquid crystal. Therefore, when the viewfinder image is viewed through the viewfinder eyepiece window, the area mark 34 or the high speed display is performed. The reference area 35 is displayed in black. In the first superimposing diffusion type liquid crystal display 33, since the illumination using the light source is not performed in the present embodiment, the power consumption of the battery is less than that of the second superimposing transmission type liquid crystal display described later.

  FIGS. 3 and 4 show the case where all 21 focus area marks 34 are lit for the sake of explanation. However, since the focus area mark 34 is not normally lit except for the selected area and the focus area, the viewfinder screen is displayed. In order to indicate where the focus area is, a marking 36 representing the presence area of the focus area is displayed on the screen 31 as shown in FIGS.

  Next, the second superimpose display will be described. Dichroic prisms 43 and 44 are disposed between the penta roof prism 32 of the finder optical system and the eyepieces 40, 41 and 42. The penta roof prism 32 and the dichroic prisms 43 and 44 are bonded to each other, and the bonding surface of the penta roof prism 32 and the dichroic prism 43 and the bonding surfaces of the dichroic prisms 43 and 44 have different angles with respect to the optical axis of the imaging lens 10. Two optical surfaces 43a and 44a are formed. Above the dichroic prisms 43 and 44, a projection lens 45, a folding mirror 46, a second superimposing transmissive liquid crystal display 47, an illumination lens 48, and an illumination LED light source 49 are arranged. Note that a prism 51 and a photometric lens 52 are disposed above the exit surface of the dichroic prism 44, and thereby subject light is guided to the photometric sensor 3.

  The second superimpose display control circuit 50 controls the second superimpose transmission type liquid crystal display 47 and the illumination LED light source 49 disposed above the dichroic prisms 43, 44, and is on the screen 31 by the interchangeable lens 10. The 21 focus area marks 34 shown in FIGS. 3 and 4 are superimposed and displayed on the subject image formed in FIG. The second superimposed transmissive liquid crystal display 47 has a shutter function, and the red light from the LED light source 49 passes through the display portion and is enlarged by the projection lens 45. Further, the second superimposing transmission type liquid crystal display 47 has two dichroic prisms 43 and 44. Reflected by the two optical surfaces 43 a and 44 a and superimposed on the subject image from the penta roof prism 32. That is, the focus area mark 34 is superimposed on the subject image.

  The focus area mark 34 displayed by the first superimpose diffusion type liquid crystal display 33 is displayed in black as described above, and the focus area mark 34 displayed by the second superimposition transmission type liquid crystal display 47. Is displayed in the color of the LED light source 49 for illumination (red in this embodiment). The focus area mark 34 displayed by the first superimpose diffusion type liquid crystal display 33 and the focus area mark 34 displayed by the second superimposition transmission type liquid crystal display 47 are the same except that the display colors are different. It is.

  In FIG. 2, a part of the subject light transmitted through the lens groups 10 a to 10 f of the interchangeable lens 10 is reflected by the main mirror 51, guided to the finder optical system, and imaged on the screen 31. The subject image formed on the screen 31 passes through the penta roof prism 32, the dichroic prisms 43 and 44, and the eyepiece lenses 41 to 42 and is guided to the finder eyepiece window, and is visually recognized by the photographer. At this time, the focus area mark 34 is superimposed on the subject image and superimposed on the subject image by the first superimposing diffusion type liquid crystal display 33 or the second superimposing transmission type liquid crystal display 47. The first superimposed diffusion liquid crystal display 33 and the second superimposed transmission liquid crystal display 47 are displays that display information physically unrelated to each other. In one embodiment, the focus area mark 34 is displayed in common. Here, “physically unrelated” means that information to be displayed is created and the created information is displayed on the finder optical system used in common for both (the display device 33 and the display device 47). This indicates that the configurations are independent from each other.

  The subject brightness BV detected by the photometric sensor 3 and the photometric circuit 2 determines which of the first superimpose diffusion type liquid crystal display 33 and the second superimpose transmission type liquid crystal display 47 performs superimpose display. Determine based on. The subject brightness BV is compared with a predetermined determination reference value BVo. If the subject brightness BV is equal to or higher than the determination reference value BVo, that is, if the subject brightness BV is high and the subject is bright, the first superimposed diffusion liquid crystal display 33 is used. Select. When the subject is bright, even if the subject light is diffused by the display segment of the diffusion type liquid crystal and the autofocus area 34 is displayed in black and superimposed on the subject image, the black area mark 34 appears in the bright subject image. As a result, it can be easily visually recognized. In addition, in this case, the diffusion type liquid crystal does not require illumination by a light source, so that power consumption of the battery can be reduced.

  On the other hand, when the subject brightness BV is lower than the determination reference value BVo, that is, when the subject brightness BV is low and the subject is dark, the second superimposed transmissive liquid crystal display 47 is selected. When the subject is dark, if the subject mark is diffused by the display segment of the diffusion type liquid crystal and the area mark 34 is displayed in black, it becomes difficult to visually recognize the area mark 34 in the dark subject image, resulting in poor visibility. Become. Therefore, when the subject is dark, the area mark 34 can be easily visually recognized in the dark subject image by displaying the area mark 34 brightly with the light transmitted through the display segment of the transmissive liquid crystal. Will be better. In addition, since the subject image is dark in this case, the area mark 34 can be sufficiently visually recognized without illuminating the transmissive liquid crystal brightly by the LED light source 49, so that the current flowing to the LED light source 49 can be reduced, and the battery power can be reduced. Consumption can be minimized.

  Note that the switching determination reference value BVo for switching between the first superimpose display and the second superimpose display is displayed while the area mark 34 is displayed on the first and second superimposes for the subject images of various luminances. What is necessary is just to confirm visibility and to determine an optimal value.

  In FIG. 2, a part of the subject light transmitted through the lens groups 10 a to 10 f of the interchangeable lens 10 is transmitted through the main mirror 51, reflected by the sub mirror 52, and guided to the focus detection sensor 12. The focus detection sensor 12 detects the focus adjustment state, that is, the defocus amount of the interchangeable lens 10 at the position of the focus area mark 34 by a known phase difference detection method. Then, a focus area to be finally subjected to focus detection is selected from 21 focus areas by a predetermined algorithm, and the selected focus area B is displayed by the first or second superimpose as shown in FIG. To do.

  Further, in FIG. 2, at the time of shooting, the main mirror 51 and the sub mirror 52 are retracted from the shooting optical path of the imaging lens 10, and the subject light is guided to the image sensor 17 through the shutter 7 and the low-pass filter 53, Imaged.

  FIG. 6 is a flowchart illustrating an imaging operation according to an embodiment. The operation of the embodiment will be described with reference to this flowchart. The microcomputer 1 starts an imaging operation when the release button half-press switch SW1 is turned on in step 1. In step 2, the photometry circuit 2 performs photometry to detect the subject brightness BV, and the exposure control circuit 4 performs exposure calculation to determine the shutter speed and the aperture value.

  In step 3, the subject brightness BV is compared with the above-described determination reference value BVo. If the subject brightness BV is equal to or greater than the determination reference value BVo and the subject is bright, the process proceeds to step 4 and the display by the first superimpose diffusion type liquid crystal display 33 is selected. On the other hand, if the subject brightness BV is less than the determination reference value BVo and the subject is dark, the process proceeds to step 5 and the display by the second superimposing transmission type liquid crystal display 47 is selected. In step 6, the focus area mark 34 is displayed by the selected superimpose method.

  In step 7, it is determined whether or not the release button full-press switch SW2 is turned on. If it is turned on, the process proceeds to step 2, and if not, the process proceeds to step 9. If the full push switch SW2 is not turned on, it is determined in step 9 whether or not the half push switch SW1 is turned on. If the half-press switch SW1 is off, the process is terminated. If the half-press switch SW1 is on, the process returns to step 7 to determine whether the full-press switch SW2 is on.

  When the full push switch SW2 is turned on, the main mirror 51 and the sub mirror 52 are retracted from the photographing optical path (mirror up) in step 8, and the diaphragm 8 is set to the aperture value obtained as a result of calculation by an actuator (not shown). In subsequent step 10, the front curtain (not shown) of the shutter 7 is unlocked and travels, and the shutter 7 is opened. In step 11, the process waits for the elapse of a predetermined time corresponding to the calculated shutter speed, and proceeds to step 12 after the elapse of the predetermined time. In step 12, the rear curtain (not shown) of the shutter 7 is unlocked to run, and the shutter 7 is put in a light shielding state. In step 13, mirror down and aperture reset are performed, and in step 14, shutter charge is performed.

  On the other hand, after the shutter 7 is opened in step 10, the imaging operations in steps 15 to 17 are executed in parallel. That is, charge accumulation of the image sensor 17 is performed at step 15, and the accumulated charge is read and transferred to the A / D conversion circuit 18 at the subsequent step 16. Thereafter, in step 17, the image processing control circuit 20 executes various image processes as described above.

  Thus, according to one embodiment, the subject brightness is detected, and one of the plurality of finder displays is selected according to the subject brightness. Specifically, as a finder display, there are a first superimpose display 33 that displays predetermined information using a diffusion type liquid crystal, and a first superimposition display 33 that illuminates a transmissive liquid crystal with an illumination member. A display device that displays information regardless of physical relationship, and includes a second superimposition display device 47 that displays a part of the predetermined information in common, and includes subject brightness and a predetermined determination criterion. When the subject brightness is equal to or higher than the determination reference value, the first superimpose display 33 is selected, and when the subject brightness is lower than the determination reference value, the second superimpose display 47 is selected. Therefore, it is possible to display information by selecting a finder display that minimizes battery power consumption according to subject brightness.

  In the above-described embodiment, an example in which the first superimpose display or the second superimpose display is automatically selected based on the result of comparing the subject brightness BV with the preset determination reference value BVo. Indicated. Since the second superimpose display is selected only when the subject brightness BV is low and the subject is dark, as compared with the conventional case where the second superimpose display is performed regardless of the subject brightness. The power consumption of the light source that illuminates the transmissive liquid crystal is reduced. However, since the second superimpose display consumes more power than the first superimpose display, if the remaining battery level of the camera is low, the second superimpose display is limited as long as the focus area mark in the viewfinder image is visible. It is desirable to perform 1 superimpose display.

  Accordingly, the remaining battery level is detected by the remaining battery level detection circuit 51 (see FIG. 1), and a determination reference value BVo for selecting whether the first superimposed display or the second superimposed display is selected is used as the remaining battery level. Change according to quantity. That is, when the remaining battery level is equal to or less than a preset amount, the subject brightness determination reference value BVo is lowered as the remaining battery level decreases, and the first superimposed display is easily selected. As a result, when the remaining battery level is low, the visibility of the focus area mark on the finder image is somewhat reduced, but it is possible to prevent the shooting from being interrupted due to the low battery level. The determination reference value BVo may be changed continuously according to the remaining battery level, or may be changed discontinuously (stepwise). Further, the battery remaining amount may be detected by measuring the voltage across the battery and referring to the remaining amount-voltage data stored in advance. Alternatively, a more accurate remaining battery level may be detected by providing an SOC (State of Chage) detection device. Alternatively, instead of changing the determination reference value BVo, which is a selection criterion for the first superimpose display and the second superimpose display, depending on the remaining battery level, the display brightness of the second superimpose display (in other words, For example, the amount of current flowing through the LED light source 49 may be changed. For example, when the subject brightness is dark and the second superimpose display is selected, but the remaining battery level is low, the current flowing to the LED light source 49 used for the second superimpose display is set. Reduce. In this case, the amount of current flowing to the LED light source 49 may be changed continuously according to the remaining battery level, or may be changed stepwise (discontinuously).

In the second superimpose display, since a bright focus area mark is displayed in the finder image, the visibility of the main subject image may be reduced. Some photographers prefer the first superimpose display. There is a case. Therefore, a selector switch (included in the setting operation member 15 shown in FIG. 1) for selecting a finder image superimpose display method is provided in the camera, and the first switch is used regardless of the automatic selection result of the above-described embodiment. The photographer may arbitrarily select either the 1 superimpose display or the second superimpose display. Alternatively, an operation member for making the above-described subject luminance determination reference value BVo variable may be provided in the camera so that the photographer can arbitrarily set it.
In the above-described embodiment, the first superimposing diffusion type liquid crystal display 33 has been described as not performing illumination using a light source. However, as described in Patent Document 2, an LED or the like is described. You may comprise so that it can display using the light source which consists of. That is, the illumination light from the light source may be incident from the end face of the diffusive liquid crystal display 33 so that the liquid crystal layer of the display 33 is displayed. In this case, if the subject brightness is dark, display using this light source and the first superimposing diffusion display 33 is performed, or the above-described second superimposing transmission type liquid crystal display is performed. It is possible to select whether to perform display using the device 47. This selection itself may be made so that the user can arbitrarily switch and set the camera when the user initially sets the camera. Alternatively, this selection may be automatically performed on the camera side. For example, the display state (for example, contrast of a display element to be displayed such as an AF area) is compared between the first superimposed display and the second superimposed display using the above light source, It is conceivable to automatically select the one judged by the camera that the visibility is good (for example, the one having the larger contrast value). Alternatively, in view of the remaining battery level, if it is determined that the remaining battery level is less than a predetermined reference level, the first superimpose display using the light source may be automatically selected. Similarly to the method described above, the current flowing through the light source (LED) in this case may be changed according to the remaining battery level.

In the embodiment described above, the first superimpose diffusion type liquid crystal display 33 and the second superimposition transmission type liquid crystal display 47 are taken as an example as a plurality of display means for displaying information within the viewfinder field of view. As described above, the display means for displaying information in the viewfinder field of view is not limited to the display means of the above-described embodiment. The plurality of display means may include display means that can be seen when the subject brightness is high and display means that can be seen when the subject brightness is low. In the plurality of display means, the same information may be displayed in the same display form, or the same information may be displayed in different display forms for each display means.
For example, as a plurality of display means for displaying focus area information within the viewfinder field of view, a first superimpose diffusion type liquid crystal display 33 that superimposes and displays a focus area mark on the viewfinder image, and a finder screen 29 below. A finder-type transmissive liquid crystal display 27 and a backlight 28 for displaying photographing information may be combined. In this case, a frame indicating the finder screen and a “point” indicating the focus area position are displayed on the transmissive liquid crystal display 27 in the finder, or “left”, “right”, “ Characters indicating the focus area position such as “center”, “upper”, and “lower” may be displayed.

  Further, the information to be displayed in superimpose is not limited to the focus area mark and the high-speed reference area of the above-described embodiment. Furthermore, information displayed in common by a plurality of displays is not limited to the focus area mark described above.

The figure which shows the structure of the camera of one Embodiment. Cross-sectional view of camera of one embodiment The figure which shows the example which displayed the focus area mark superimpose on the finder picture The figure which shows the example which displayed the focus area mark and the crop high-speed reference area on the finder image The figure which shows the example which displayed the selection focus area mark on the finder image superimpose Flowchart showing operation of one embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microcomputer 2 Photometry circuit 3 Photometry sensor 26 In-finder display control circuit 27 In-finder transmission type liquid crystal display 30 First superimpose display control circuit 33 First superimpose diffusion type liquid crystal display 47 Second superimposition transmission Type liquid crystal display 49 LED light source 50 for illumination Second superimpose display control circuit

Claims (10)

An imaging apparatus comprising a plurality of display means for displaying information within the viewfinder field,
First display means for displaying predetermined information;
Display means for displaying information physically unrelated to the first display means, second display means for commonly displaying at least a part of the predetermined information;
Luminance detection means for detecting subject luminance;
An imaging apparatus comprising: a display selection unit that selects one of the plurality of display units according to a luminance detection value obtained by the luminance detection unit. The imaging device according to claim 1,
The display selection unit compares the luminance detection value with a preset reference value, and selects one of the plurality of display units based on a comparison result. The imaging device according to claim 2,
A remaining amount detecting means for detecting a remaining amount of a battery for supplying power to the photographing device;
An imaging apparatus comprising: reference value changing means for changing the reference value in accordance with a battery remaining amount detected value by the remaining amount detecting means. The imaging device according to claim 2,
An imaging apparatus comprising a reference value changing operation member for changing the reference value. In the imaging device according to any one of claims 1 to 4,
An imaging apparatus, comprising: a selection operation member for selecting one of the plurality of display means, wherein priority is given to selection by the selection operation member over selection by the display selection means. In the imaging device according to any one of claims 1 to 4,
The imaging apparatus according to claim 1, wherein the first display means displays information by diffusing liquid crystal, and the second display means displays information by illuminating the transmissive liquid crystal with an illumination member. In the imaging device according to claim 6,
The display selection unit selects the first display unit when the luminance detection value is greater than or equal to the reference value, and selects the second display unit when the luminance detection value is less than the reference value. An imaging device characterized by the above. In the imaging device according to claim 7,
The imaging apparatus according to claim 1, wherein the first display unit and the second display unit display information superimposed on a subject image formed by a photographic lens. In the imaging device according to any one of claims 1 to 8,
The plurality of display means display the commonly displayed information in the same display form. In the imaging device according to any one of claims 1 to 8,
The plurality of display units display the commonly displayed information in different display forms.

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