JP2010134026A - Device for displaying measurement area information for imaging equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device or the like for displaying measurement area information for imaging equipment capable of avoiding the complication of an electric circuit that makes a measurement area of a display part displayable in a plurality of discriminable forms, and a mounting constitution. <P>SOLUTION: The device for displaying measurement area information includes: a liquid crystal display device 22 for displaying a plurality of measurement areas to be superimposed on a subject image; a measurement area selection mode changing means; and a measurement area moving designating member. The changing means performs switching between a mode in which operation to designate the movement of a specific measurement area is allowed and a mode in which such an operation is not allowed. The designating member designates the movement of the specific measurement area in the mode in which the operation to designate the movement thereof is allowed. A segment of the selected specific measurement area out of segments showing the measurement areas is set into a state that a common drive voltage is applied, and segments of other measurement areas are set into a state that the common drive voltage is not applied. The common drive voltage in the mode in which the operation to designate the movement thereof is allowed is made higher than the common drive voltage in the mode in which such an operation is not allowed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a measurement region information display device that displays a measurement region such as a focus detection region having a transmissive liquid crystal display device that can display necessary information on an optical image, and a finder device having the measurement region information display device. The present invention relates to imaging equipment. In particular, the present invention relates to a measurement area information display device having a superimpose liquid crystal display device used for an optical viewfinder of a camera, a finder device, and the like.

2. Description of the Related Art Conventionally, a so-called superimpose display is performed in which a liquid crystal display device that displays information is incorporated in a finder device such as a camera, and various types of information are superimposed and displayed in the viewfinder field of the camera or the like.

Patent Document 1 discloses a specific example of a camera finder device capable of superimposing display. In this finder apparatus, a reflection surface having an optical axis different from the finder optical axis is formed by a half mirror or a prism behind a penta roof prism as an erect image forming member on the finder screen (focusing screen). Then, the display pattern of the liquid crystal display device arranged in the vicinity of the penta roof prism can be observed over the finder image on the screen through the reflection surface.

Patent Document 2 discloses a camera capable of displaying information by distinguishing a plurality of (for example, three types) states for the same display pattern as a camera capable of another superimpose display. This camera has an in-finder display device in which a transmissive liquid crystal panel is arranged in the vicinity of the screen of the finder so that the finder image on the screen and the information pattern of the liquid crystal panel can be observed. In this in-finder display device, the light diffusivity of the display pattern is changed by changing the drive voltage applied to each pattern representing a plurality of measurement (for example, focus detection) areas provided in the screen. Accordingly, the corresponding area is, for example, a focus detection area selected and focused from a plurality of areas, a focus detection area that is selected and not focused on the subject image, or a focus detection that is not selected. It is possible to display the status of the area in three stages.
Japanese Patent Laid-Open No. 11-237659 JP 2000-75393 A

However, Patent Document 1 is limited to the description mainly regarding the optical configuration for achieving the superimpose display, and particularly relates to display identification when selecting a measurement region such as a focus detection region of autofocus. is not.

Further, since the apparatus described in Patent Document 2 is configured to individually change the drive voltage of the display pattern representing the measurement area, when the number of display patterns, that is, the number of measurement areas such as focus detection increases, The number of control terminals also increases by the same number. Therefore, it is inevitable that the electric circuit and the mounting configuration are complicated, and in some cases, the number of displayable measurement areas may be limited.

In view of the above problems, the measurement area information display device of the imaging apparatus of the present invention has the following characteristics. The information display device includes a transmissive liquid crystal display device that displays a plurality of measurement regions superimposed on a subject image, a measurement region selection mode changing unit, and a measurement region movement instruction member. The measurement area selection mode changing means switches between a mode in which an operation for instructing movement of a specific measurement area among the plurality of measurement areas can be performed and a mode incapable of performing an operation. The measurement region movement instructing member instructs to move the selected specific measurement region in the mode by switching the measurement region selection mode changing means capable of instructing movement of the specific measurement region. Further, among the segments indicating the plurality of measurement regions of the liquid crystal display device, the segment of the selected specific measurement region is set to the first state in which the common drive voltage is applied. On the other hand, the segment of the measurement region other than the selected specific measurement region is set to the second state where the common drive voltage is not applied. Further, in the mode in which the movement instruction of the specific measurement area can be instructed with respect to the common driving voltage of the liquid crystal display device in the mode by the switching of the measurement area selection mode changing means incapable of moving the specific measurement area. The common drive voltage of the display device is increased.

According to the present invention, since the drive voltage is common to at least some groups of the plurality of segments of the liquid crystal display device representing the measurement area such as the focus detection area, even if the number of measurement areas increases, Implementation complexity can be avoided. Further, with such a relatively simple configuration, the display state of the segment can be changed depending on whether the common drive voltage value is controlled and the application state or non-application state is set. Thereby, a measurement area information display device of an imaging device that can identify a specific measurement area segment selected by a photographer among other segments of a plurality of measurement areas, another selectable measurement area segment, or the like, A finder device or the like can be realized.

Hereinafter, an embodiment of a measurement area information display device for an imaging apparatus according to the present invention will be described. What is important in the apparatus of the present invention is as follows. The drive voltage is common to at least some groups of multiple segments indicating the measurement area, and the display state of the segment can be identified by controlling the common drive voltage value and applying or not applying it. It is possible to change. As a result, with a relatively simple configuration, an information display that can identify whether a segment of a plurality of measurement areas is a specific measurement area segment selected by the photographer, another selectable measurement area segment, or the like The device can be realized.

Based on the above concept, the basic embodiment of the information display device of the present invention has the following configuration. The information display device includes a transmissive liquid crystal display device that displays a plurality of measurement regions superimposed on a subject image formed on a predetermined surface, a measurement region selection mode changing unit, and a measurement region movement instruction member. . The measurement area selection mode changing means is for switching between a mode in which an operation for instructing movement of a specific measurement area among the plurality of measurement areas can be performed and a mode in which the operation cannot be performed. The measurement region movement instructing member is for instructing movement of the selected specific measurement region in the mode by switching the measurement region selection mode changing means capable of performing an operation of instructing movement of the specific measurement region. With such a configuration, the segment of the specific measurement region selected among the segments indicating the plurality of measurement regions of the liquid crystal display device can be set to the first state where the common drive voltage is applied by the switch means or the like. . On the other hand, the segment of the measurement region other than the selected specific measurement region can be set to the second state where the common drive voltage is not applied by the switch means or the like. Further, in the mode in which the movement instruction of the specific measurement area can be instructed with respect to the common driving voltage of the liquid crystal display device in the mode by the switching of the measurement area selection mode changing means incapable of moving the specific measurement area. The common drive voltage of the display device can be increased. The first state is also referred to as a lighting state in the embodiments described later. The second state is also called a non-lighting state.

In the basic embodiment, more specific embodiments as described below are possible. A measurement area information display device of an imaging device such as a single-lens reflex camera can include a focusing screen, a light emitting element such as an LED, an erect image forming member, and a reflecting surface (see the first embodiment described later). . In order to observe the subject image from the photographic lens, the focusing screen is disposed on a planned imaging plane on which at least a part of the photographic light beam reflected substantially at a right angle by a mirror is formed. The light emitting element is disposed in the vicinity (for example, in front of the camera) so as to supply a backlight to the liquid crystal display device. An erect image forming member such as a penta roof prism is disposed above the focusing screen (above the optical path of the photographing light beam). The reflecting surface is provided on a part of the eyepiece optical member behind the upright image forming member (backward in the optical path of the photographing light beam). Thus, by projecting the light beam from the light emitting element onto the reflecting surface via the liquid crystal display device, segments indicating a plurality of measurement areas of the liquid crystal display device are imaged on the focusing screen. Overlay the image and display it.

In addition, the display unit that displays the measurement area of the liquid crystal display device includes a first plurality of measurement areas and a second plurality of measurements different from the first plurality of measurement areas as the plurality of measurement areas. A region. The plurality of segments indicating the first plurality of measurement regions and the plurality of segments indicating the second plurality of measurement regions are configured such that a common drive voltage can be applied independently of each other. (Refer to a second embodiment described later).

In the embodiments described later, the measurement area of the liquid crystal display device is a focus detection area, but the measurement area can also be used as a photometry area in the photometric sensor. Also in this case, as described above, a specific photometry area is selected or moved, and the subject image is measured in the selected specific photometry area, and the aperture and the like are controlled based on this. . Such control is performed by a control means such as a CPU described later.

(First embodiment)
FIG. 1 shows a schematic configuration of a single-lens reflex camera according to the first embodiment of the present invention. In this figure, 1 is a camera body, and 2 is a photographing lens attached to the camera body. In FIG. 1, the photographing lens 2 is shown as if it is composed of two lenses, a focusing lens 3 and a variable power lens 4 for the sake of convenience, but it is actually composed of a larger number of lenses.

Reference numeral 5 denotes a main mirror. The main mirror 5 is obliquely arranged in the photographing optical path during finder observation, reflects a part of the light beam incident from the photographing lens 2 and guides it to the optical finder system, and retracts outside the photographing optical path during photographing. A sub-mirror 6 reflects the light beam transmitted through the main mirror 5 toward the lower side of the camera body 1 during finder observation.

Reference numeral 7 denotes a shutter, and 8 denotes a photosensitive member for recording a photographed image. The photosensitive member 8 is composed of a silver salt film, a solid-state imaging device such as a CCD or MOS type, or an imaging tube such as a vidicon. In the following description, it is assumed that the photosensitive member 8 is a solid-state image sensor.

Reference numeral 9 denotes a phase difference type focus detection device. The focus detection device 9 includes a field lens 9a, reflection mirrors 9b and 9c, a secondary imaging lens 9e, an aperture 9d, a line sensor 9f composed of a plurality of CCDs, and the like disposed in the vicinity of the imaging surface of the photographing lens 2. Is done. The focus detection device 9 detects the focus adjustment state in a plurality of focus detection areas in the object field, corresponding to each of 19 focus detection areas in the finder field described later.

Reference numeral 10 denotes a focusing plate disposed on the planned imaging plane of the photographic lens 2. Reference numeral 11 denotes a condenser lens for effectively guiding the light beam from the photographing lens 2 to the eyepiece lens 16. Reference numeral 13 denotes a penta roof prism that bends the optical path of the light beam that has passed through the focusing plate 10 and the condenser lens 11 and guides it to the eyepiece system. A field mask 12 for defining a finder field area is disposed between the condenser lens 11 and the penta roof prism 13.

On the exit surface of the penta roof prism 13, prisms 14 and 15 for changing the optical path of the light beam emitted from the penta roof prism 13 are bonded and fixed. The surfaces 14a and 14b of the prism 14 are coated with, for example, a coating having a dichroic characteristic that transmits visible light and reflects infrared light, so that infrared light for superimpose display described later is provided. It is guided to the photographer's eyeball 17. An eyepiece 16 is disposed behind the prism 15, and the light flux of the subject image formed on the focusing screen 10 reaches the eyeball 17 of the photographer through the eyepiece 16, and the subject image is observed by the photographer. Is done.

Reference numerals 18 and 19 denote an imaging lens and a photometric sensor for measuring the subject brightness in the finder field (photographing screen), respectively. The imaging lens 18 positions the focusing plate 10 and the photometric sensor 19 in a conjugate imaging relationship via the reflected light path in the penta roof prism 13 and the prism 14.

Reference numeral 20 denotes a high-intensity LED that emits infrared light that can be visually recognized even in a bright subject, and 21 denotes a condenser lens. The condenser lens 21 functions as a condenser lens that makes the LED 20 and the photographer's eyeball (pupil) 17 have a conjugate imaging relationship, and efficiently enters the light from the LED 20 into the observer's eyeball 17.

22 is a field effect type twisted nematic mode (Twisted
This is a TN liquid crystal display unit (hereinafter referred to as a superimposing LCD) using Nematic mode. The superimposing LCD 22 forms 19 focus detection areas, which will be described later, in the finder field of view, and is patterned by a plurality of segments (display units) so that only selected segment areas can transmit light.

The light beam emitted from the LED 20 passes through the transmission segment of the condenser lens 21 and the superimposing LCD 22, passes through the first light projection lens 23, the mirror 24, and the second light projection lens 25, and reaches the prism 14. Incident. The light incident on the prism 14 is reflected by the dichroic surface 14a and reaches the dichroic surface 14b. Here, the subject image formed on the focusing screen 10 and the pattern of the transmission segment overlap, reach the eyeball 17 of the observer through the prism 15 and the eyepiece 16, and are observed.

Reference numeral 27 denotes an in-finder LCD for displaying photographing information such as an aperture value and a shutter time outside the finder field of view, and is composed of a TN liquid crystal display unit like the superimposing LCD 22. The in-finder LCD 27 is illuminated by the light from the illumination LED 26, and the light transmitted through the LCD 27 is guided into the finder by the triangular prism 28, so that photographing information is displayed outside the finder field. As a result, the photographer can check the set photographing information.

Reference numeral 29 denotes an aperture provided in the photographic lens 2, and reference numeral 30 denotes an aperture driving device including an aperture control circuit 109 described later. Reference numeral 31 denotes a lens driving motor, and reference numeral 32 denotes a lens driving mechanism including a driving gear and the like. A photo coupler 33 detects the rotation of the pulse plate 34 interlocked with the lens driving mechanism 32 and transmits lens driving information to the lens focus adjusting circuit 110 (see FIG. 2). The focus adjustment circuit 110 drives the lens driving motor 31 based on the lens driving information and the calculated lens driving amount information up to the focusing position, and moves the focusing lens 3 to the focusing position.

A mount contact 35 serves as a communication interface between the camera body 1 and the taking lens 2. Reference numeral 36 denotes a manual focus ring for driving the focusing lens 3 by manual operation. The focusing lens 3 can be moved directly to the in-focus position by rotating the ring 36 when the photographer adjusts the focus.

Reference numeral 37 denotes a monitor LCD composed of a TFT liquid crystal for displaying image data obtained by the image sensor 8.

FIG. 2 shows a configuration of an electric circuit built in the single-lens reflex camera. In this figure, the components described in FIG. 1 are denoted by the same reference numerals as in FIG.

The camera body 1 incorporates a central processing unit (hereinafter referred to as CPU) 100 constituting a microcomputer. The CPU 100 includes a digital circuit 101, a photometry circuit 102, an automatic focus detection circuit 103, a signal input circuit 104, an LCD drive circuit 105, an LED drive circuit 106, a shutter control circuit 107, a motor control circuit 108, an aperture control circuit 109, and a focus. The adjustment circuit 110 is connected. The EEPROM 100a attached to the CPU 100 has a storage function for storing various data.

The digital circuit 101 includes an image sensor driving circuit 101a, a RAM 101b, a signal processing circuit 101c that converts an imaging signal stored in the RAM 101b into predetermined image data, and a flash memory 101d for storing the image data. . The image sensor drive circuit 101 a drives the image sensor 8 and reads an image signal from the image sensor 8. The RAM 101b stores the read imaging signal.

The photometry circuit 102 amplifies the luminance signal output corresponding to the brightness of the object scene from the photometry sensor 19, logarithmically compresses and A / D converts it, and sends it to the CPU 100 as the object luminance information from each sensor 19. The photometric sensor 19 includes 63 photodiodes SPC1 to SPC63 corresponding to each photometric area set to divide the viewfinder field into 63 so as to include each focus detection area.

The automatic focus detection circuit 103 performs A / D conversion on the voltage obtained from the CCD line sensor unit 9f composed of 19 sets of line sensors CCD-1 to CCD-19 corresponding to 19 focus detection areas, and sends it to the CPU 100. send.

SW1 is a switch that is turned on by a first stroke operation of a release button (not shown) and starts camera photometry, focus detection operation, and the like. SW2 is a switch that is turned on by the second stroke operation of the release button to start the release operation.

SW-DIAL1 is a switch for selecting various information (for example, shutter speed, aperture value, etc.) necessary for shooting. SW-DIAL2 is also a switch used for setting various shooting modes, and is a sub-electronic dial for supplementing the operation of SW-DIAL1, which is an electronic dial.

SW-M is a main switch for setting the camera in an operating state. SW-AF / MF is a switch for selecting whether the focus adjustment, that is, the focusing of the photographing lens 2 is performed automatically or manually (manual), and is provided in the photographing lens 2 in this embodiment. Yes. SW-AFS is a switch for switching between an arbitrary focus detection area selection mode and an automatic focus detection area selection mode. In the arbitrary focus detection region selection mode, the photographer manually selects a specific focus detection region from among 19 focus detection regions set as auto focus focus detection regions in this camera. Is possible. In the automatic focus detection region selection mode, the region for performing the focus detection operation is automatically determined by a predetermined algorithm in the camera among the 19 focus detection regions. In the above-described automatic focus detection area selection mode, one or one focus detection area is automatically selected by a predetermined algorithm, and in the arbitrary focus detection area selection mode, a specific focus detection area is regarded as one or one focus detection area. Is arbitrarily selected.

SW-T, SW-B, SW-L, and SW-R are focus detection areas for instructing the moving direction of a specific focus detection area when the SW-AFS is in the arbitrary focus detection area selection mode. It is a movement instruction switch (measurement area movement instruction member). The focus detection area can be moved upward by pressing SW-T, downward by pressing SW-B, left by SW-L, and downward by SW-R. It becomes. The focus detection area is determined by ending a predetermined timer or performing another switch operation.

In this embodiment, a dedicated switch is provided as the focus detection area movement instruction switch. However, for example, the same function can be obtained by operating the electronic dial of SW-DIAL1 or the sub electronic dial of SW-DIAL2. It is possible to assign.

SW-AFD is a mode in which, when the camera is capable of photometry and focus detection operation, an operation for further selecting and moving the focus detection area once determined in the arbitrary focus detection area selection mode described above, It is a switch that switches between impossible modes. This focus detection area selection mode change switch is a measurement area selection mode change means. If this focus detection area selection mode change switch is in the ON state, the camera is in a state where photometry and focus detection operations are possible, and the following is performed. That is, the focus detection area movement for instructing the movement direction of the focus detection area in conjunction with the operation of the SW-T, SW-B, SW-L, SW-R, or SW-DIAL1, SW-DIAL2. The operation of the indicator switch becomes effective.

Signals from these switches are input to the signal input circuit 104 and transmitted to the CPU 100 via a data bus. Each signal from SW-DIAL 1 and SW-DIAL 2 is input to an up / down counter in signal input circuit 104. The up / down counter counts the signals from these switches, that is, the amount of rotation click of the electronic dial, and transmits the count value to the CPU 100.

The LCD drive circuit 105 is an LCD drive circuit for displaying and driving the superimposing LCD 22, the finder LCD 27, and the monitor LCD 37, and controls the display contents of each LCD according to signals from the CPU 100.

The LED driving circuit 106 controls lighting of the superimposing LED 20 and the finder LED 26. The shutter control circuit 107 energizes the magnet MG-1 to run the front curtain in the shutter charge state, and then energizes the magnet MG-2 to run the rear curtain. As a result, a predetermined amount of light is accumulated in the image sensor 8. The motor control circuit 108 controls the motor M1 that charges the main mirror 5 and the motor M2 that charges the shutter 7. The shutter control circuit 107 and the motor control circuit 108 operate a series of release sequences in the camera.

As shown in FIG. 1, the aperture control circuit 109 and the focus adjustment circuit 110 are arranged in the photographing lens 2 and transmit signals to the CPU 100 via the mount contact 35.

Next, FIG. 3 shows a configuration in the viewfinder field that can be seen when looking through the optical viewfinder in this embodiment. In this figure, the superimpose LCD 22 is fully lit. In this fully lit state, all of the segments (for example, composed of transparent electrodes having a predetermined shape) indicating a plurality of measurement regions of the liquid crystal display device are shared by the LCD drive circuit 105 via each switch means in the on state. The lighting state is conducted to the driving voltage source. In practice, there is also a display by the in-finder LCD 27 for displaying information related to various photographings in the peripheral part of the viewfinder field, but it is omitted in FIG.

In FIG. 3, the outer frame is formed by the field mask 12. Reference numerals 1001 and 1002 are engraving lines that are always indicated on the focus plate by integrally forming a fine prism shape on the matte surface, which is the planned imaging surface of the focus plate 10. Reference numeral 1001 denotes a range in which autofocus can be detected, and reference numeral 1002 denotes a minimum photometric range. Reference numerals 2201 to 2219 denote 19 sets of display indices (segments) that are superimposed on the superimpose LCD 22 and are arranged so as to correspond to 19 focus detection areas.

FIG. 4 is an explanatory diagram showing the relationship between the segment density and the bias voltage of the liquid crystal display device used for the superimposing LCD 22 or the like. In general, the relationship between the density of the segment Sd in the lit state, the concentration of the segment Sp in the non-lit (off) state, and the bias voltage for driving the liquid crystal display is as shown in FIG. In the lighting state, as described above, for example, a bias voltage from a common drive voltage source is applied to the segment, and the liquid crystal portion corresponding to the segment is in a light transmission state in which light is sufficiently transmitted. In the non-lighting state, for example, the bias voltage from the common drive voltage source is not applied to the segment by the switch means in the off state, and the liquid crystal portion corresponding to this is in the non-transmissive state that does not transmit much light. The switch means is provided by a transistor switch or the like for each segment.

Usually, it is possible to increase the concentration of the lighting segment Sd by increasing the driving voltage value of the liquid crystal display device, but at the same time a slight leakage voltage is generated in the non-lighting segment Sp. The lighted segment is also displayed lightly. Therefore, as for the driving voltage value of the normal liquid crystal, the non-lighted segment Sp concentration is set to the pA point of the low voltage A as the non-lighted segment, and the lighted segment Sd concentration is set to the dA point of the same voltage A. It will be set.

Further, when the driving voltage value of the liquid crystal display device is the voltage B in FIG. 4, the driving voltage value is higher than the voltage A. Therefore, the segment in the lighting state is the dB point, and the display density of the lighting segment is further increased. Becomes darker. The segment in the non-lighted state becomes the pB point, and the display density is lower than dB, but the display is darker than the pA point. That is, even in a non-lighted segment, the density can be controlled by setting the value of the voltage B to a predetermined value.

In this embodiment, a high-intensity infrared light LED 20 is arranged on the back surface of the superimposing LCD 22. Further, on the surface of the liquid crystal display panel of the superimposing LCD 22, a masking process (not shown) is performed by, for example, resist printing or vapor deposition in order to shield the portion other than the square segment indicating the focus detection area. I do. With this configuration, when the voltage applied to the curves Sd and Sp is increased, the transmittance of each segment portion is increased, and more light flux from the LED 20 is guided to the finder optical system. Each segment part is formed of, for example, a transparent electrode whose periphery is a light-shielding part as described above, and the liquid crystal layer part sandwiched between the transparent electrode and the common transparent electrode is common to the segment part. The transmission state and non-transmission state are set according to the on / off state of the bias voltage.

That is, although the vertical axis of the graph in FIG. 4 is described as the segment density, in this embodiment, the transmittance of the square segment portion indicating each focus detection area of the superimpose LCD 22 is the segment density in FIG. It has the same meaning.

FIG. 5 shows an example of display when the drive voltage of the liquid crystal display device used in the superimposing LCD 22 described in FIG. 4 is changed. As a driving voltage of the liquid crystal display device used for the superimposing LCD 22, the case where the display is performed with the voltage A shown in FIG. 4 is shown in FIG. 5A and the case where the display is performed with the voltage B is shown in FIG. Shown in (b).

In FIG. 5A, the driving voltage of the liquid crystal display device used for the superimposing LCD 22 is performed by the voltage A described above. Therefore, only the lighting segment 2208 selected as the specific focus detection area is displayed darkly near the left inside the engraving line 1001 indicating the autofocus detectable range in the finder. Further, the non-lighting segments 2201 to 2207 and 2209 to 2219 assigned as other focus detection areas not selected as the specific focus detection areas are hardly visible in the viewfinder.

On the other hand, in FIG. 5B, the driving voltage of the liquid crystal display device used for the superimposing LCD 22 is performed by the voltage B described above. In this case, the lighting segment 2208 indicating the focus detection area selected as the specific focus detection area is clearly displayed near the left inside the marking 1001 indicating the autofocus detectable range in the finder. In addition, the non-lighting segments 2201 to 2207 and 2209 to 2219 assigned as other focus detection regions not selected as the specific focus detection region are also displayed in the finder in a thinner state than the lighting segment 2208.

FIG. 6 shows an operation flowchart of the entire camera (mainly the CPU 100) configured as described above. Hereinafter, the operation of the camera will be described with reference to this flowchart and FIGS. 1, 2, and 7 to 9. In the flowchart of FIG. 6, “focus detection” is sometimes expressed by “side distance”.

First, when the photographer rotates the electronic dial to a position where SW-M is turned on, the camera power is turned on (# 300), and the CPU 100 waits until SW1 is turned on (# 301).

Next, the CPU 100 confirms whether the SW-AFS is in the automatic focus detection area selection mode or the arbitrary focus detection area selection mode (# 302). In the automatic focus detection area selection mode, a predetermined focus detection is performed by a predetermined algorithm. An area is selected (# 303). Here, several methods are conceivable as an algorithm for automatically selecting a focus detection area, but a near-point priority algorithm in which a central focus detection area is weighted, which is often employed in a so-called multipoint AF camera. Is effective.

Further, at this stage (# 303), it is not possible to specify where the focus detection area in the finder field is in focus, so this mode (automatic focus detection area selection mode) is shown in FIG. In this way, the focus detection area is in a state where nothing is lit. Further, the driving voltage of the liquid crystal superimposing LCD 22 is maintained in the display mode performed by the voltage A described above in the subsequent operations.

Thereafter, the automatic focus detection circuit 103 is caused to perform a focus detection operation in the focus detection region selected here (# 308).

On the other hand, when the arbitrary focus detection area selection mode is set in # 302, the display index corresponding to the selected focus detection area is superimposed on the viewfinder field (# 304). As shown in FIG. 7B, the display voltage in the viewfinder field here is changed to the display mode in which the driving voltage of the liquid crystal superimposing LCD 22 is performed by the voltage B described above. For example, in FIG. 7B, the focus detection area 2210 is selected as a lighting segment that is an arbitrary focus detection area. The other 18 points of the focus detection areas 2201 to 2209 and 2211 to 2219 are in a non-lighted segment state as selectable focus detection areas, but the focus detection areas are thinly displayed.

Further, if any of the focus detection area movement instruction switches (SW-T, SW-B, SW-L, SW-R) is pressed, the focus detection area is moved to the segment position of the corresponding focus detection area. And display (# 305). For example, when the focus detection area movement instruction switch SW-L is pressed twice, as shown in FIG. 7C, the focus detection area 2208 is displayed as a lighting segment that is an arbitrary focus detection area. The other 18 points of the focus detection areas 2201 to 2207 and 2209 to 2219 are in a non-lighted segment state as selectable focus detection areas, but are displayed in a thin state. Further, the drive voltage of the liquid crystal superimposing LCD 22 is maintained in the display mode performed by the voltage B described above in the subsequent operations.

The focus detection area movement instruction in # 305 can be interrupted by an AND condition in which the next focus detection area selection mode state determination (# 306) is ON and SW1 is ON. It is.

Next, the state of the focus detection area selection mode change switch (SW-AFD) is determined (# 306). In this embodiment, the physical switch state determination has been described. However, for example, it may be changed by a parameter value stored in the EEPROM 100a attached to the CPU 100.

When the focus detection area selection mode change switch is in the ON state, the automatic focus detection circuit 103 is caused to perform the focus detection operation in the selected focus detection area while maintaining the display form described in # 304 ( # 308). When the focus detection area selection mode change switch is in the OFF state, only the display index corresponding to the focus detection area selected in # 306 is displayed as a superimposed segment in the viewfinder field (# 307). At this time, the driving voltage of the liquid crystal superimposing LCD 22 is changed to the display mode performed by the voltage A described above. Therefore, the display in the viewfinder field here is a state in which the focus detection area 2208 is displayed as a lighting segment of the arbitrary focus detection area as shown in FIG. The other 18 points of the focus detection areas 2201 to 2209 and 2211 to 2219 cannot be visually recognized as non-lighting segments as non-selectable focus detection areas. In the subsequent operations, this display form (display form 3) is maintained.

Subsequent display modes maintain the aforementioned display state until the state of the focus detection area selection mode change switch (SW-AFD) is changed to the ON state.

Thus, the automatic focus detection circuit 103 is caused to perform the focus detection operation in the selected focus detection region (# 308). When the focus detection operation by the automatic focus detection circuit 103 is performed, the CPU 100 determines whether or not the selected focus detection region is a region where focus detection is impossible (# 309). If not possible, the CPU 100 sends a signal to the LCD drive circuit 105 to cause a focus mark (not shown) of the LCD 27 in the viewfinder to blink. In this way, the photographer is warned that focus detection is impossible (# 310), and this operation is continued until SW1 is turned off (# 311).

If the selected focus detection area is an area where focus detection is possible and the focus adjustment state in this focus detection area is not in focus (# 312), the CPU 100 sends a signal to the lens focus adjustment circuit 110 to shoot. The lens 3 is driven to focus (# 313). After driving the lens, the automatic focus detection circuit 103 performs focus detection again (# 308), and determines whether or not the focus detection area is in focus (# 312). When the focus of the focus detection area is obtained, the CPU 100 sends a signal to the LCD drive circuit 105 to light a focus mark (not shown) of the LCD 27 in the finder.

On the other hand, in the automatic focus detection area selection mode, as shown in FIG. 8A, the focus detection area (for example, 2208) corresponding to the automatically selected focus detection area is lit at high brightness for a moment. The user is in focus (# 314). When the focus detection area selection mode change switch is ON in the arbitrary focus detection area selection mode, as shown in FIG. 8B, the focus detection area 2208 displayed as the arbitrary focus detection area is momentarily bright. To inform the photographer that the subject is in focus (# 314). This momentary high-intensity lighting can be performed by momentary high-intensity light emission of the LED 20.

At this time, the above-described focus detection area movement instruction of # 305 is made possible as an interrupt operation. Accordingly, the other 18 points of the focus detection areas 2201 to 2207 and 2209 to 2219 are in a non-lighted segment state as a focus detection area that can be selectively moved by the focus detection area movement instruction operation of the photographer, but are thinly focus detection areas Will be displayed. Further, in the arbitrary focus detection area selection mode and when the focus detection area selection mode change switch is OFF, the same display as in FIG. 8A is performed.

Next, when the photographer sees that the in-focus state is displayed in the finder and recognizes that the focus detection area is not correct and turns off SW1 (# 315), CPU 100 continues until SW1 is turned on. Wait (# 301). Further, when the photographer looks at the focus detection area displayed in focus and continues to turn on SW1 (# 315), the CPU 100 transmits a signal to the photometry circuit 102 to perform photometry (# 316). .

At this time, in this embodiment, the exposure value is calculated by performing a photometric calculation weighted on a photometric area (not shown) including the focused focus detection area. Then, the aperture value (not shown) of the in-finder LCD 27 is displayed as the calculation result.

Next, the CPU 100 determines whether or not SW2 is ON (# 317). If SW2 is OFF, the state of SW1 is confirmed again (# 315). When SW2 is ON, the CPU 100 transmits signals to the shutter control circuit 107, the motor control circuit 108, and the aperture drive circuit 108, respectively. That is, first, the motor M2 is energized, the main mirror 5 is raised, the diaphragm 29 is narrowed, and then the magnet MG1 is energized to run the front curtain of the shutter 7. The aperture value and the shutter speed (at the shutter speed) are determined based on the previously calculated exposure value and the set sensitivity of the image sensor 8. Then, after the determined shutter time has elapsed, the magnet MG2 is energized to run the rear curtain of the shutter 7 and the exposure is completed.

When the exposure is completed, the motor M2 is energized again, the photosensitive member 8 is moved forward, and a series of shutter release sequences is completed (# 318). Thereafter, the CPU 100 waits until SW1 is turned on again (# 301).

In this embodiment, the focus detection operation is performed by a phase difference detection method. Hereinafter, this method will be described with reference to FIGS. As shown in FIG. 1, a part of the light incident from the photographing lens 2 is transmitted through the main mirror 5 and reflected downward by the sub mirror 6. The light reflected by the sub-mirror 6 passes through the primary focus plane p, and further passes through the field lens 9a, the reflection mirror 9b, and the stop 9d, and reaches a secondary imaging lens 9e called an eyeglass lens, where two images A , B are formed separately.

The two separated images A and B are reflected by the reflection mirror 9c and projected onto the line sensor unit 9f. The line sensor unit 9f is configured by arranging photoelectric conversion elements (line sensors SPC) of a predetermined number of pixels at a predetermined pitch, and the two images A and B projected on the line sensor unit 9f are photoelectrically converted. As a result, the output shown in FIG. 9 is obtained.

This output varies depending on the relative positional relationship between the light amount distributions of the two images A and B, that is, the amount of deviation of the light amount distribution, and the amount of deviation of the light amount distribution varies depending on the focus adjustment state of the photographing lens 2. For example, the amount of lateral deviation appears in the arrangement direction of the elements on the line sensor in accordance with the amount of defocus from the planned imaging plane (primary focus plane) p of the photographic lens 2.

9A shows the state of the subject image on the line sensor in the focused state, FIG. 9B shows the front pin state, and FIG. 9C shows the distance between the two subject images. Is determined to be in focus when the value reaches a predetermined value.

As described above, according to the present embodiment, when the operation for selecting a specific focus detection area is not possible, the selected focus detection area segment is clearly displayed and other selections can be made. Impossible focus detection areas are not displayed. Therefore, the viewfinder field is less disturbing when observing the subject. In the mode in which an operation for selecting a specific focus detection area is possible, the focus detection area that can be selectively moved is a non-lighted segment by increasing the overall drive voltage of the liquid crystal display device than in the mode. Even if it exists, it is displayed thinly on the liquid crystal display. Therefore, it can be visually recognized as the focus detection area of the selected movement destination. As a result, the position on the finder of the focus detection area where the selective movement can be performed is shown, so that the framing considering the relative position between the subject and the focus detection area to be moved and the operability of selecting the focus detection area are improved.

The switching of the display state according to the mode for selecting the specific focus detection area described above is a configuration for switching the entire drive voltage of the liquid crystal display device. Therefore, it is possible to realize a configuration for a conventional display device without greatly changing an electric circuit or a mounting scale without providing an independent control port for each display segment.

Furthermore, since the finder display state differs depending on the mode for selecting the specific focus detection area, it is possible to determine at a glance which state the focus detection area selection mode is in.

In addition, a light beam for displaying the state of the focus detection area guided from the light emitting element disposed on the back surface of the liquid crystal display device to the finder optical system, and a light beam of the subject image from the focusing screen for detecting the subject luminance during photographing to the photometric sensor Is different. Since the optical paths are different from each other in this way, it is possible to always display the state of the focus detection area using the light emitting element, including when the luminance of the subject is detected before photographing.

Further, even if the focus detection area display portion of the liquid crystal display device is small, it can be displayed in a large area in the finder field. At the same time, since the mechanism of the focus detection area display unit including the liquid crystal display device and the mechanism of the focusing screen unit are configured by different parts, the configuration of the focusing screen unit can be simplified. This makes it possible to provide a low-cost camera that allows the user to replace the focusing screen.

(Second embodiment)
A second embodiment of the present invention will be described. FIG. 10 shows a configuration in the viewfinder field that can be seen when looking through the viewfinder in the second embodiment of the present invention.

In FIG. 10A, reference numerals 2201 to 2219 denote 19 sets of first display index groups which are superimposed on the superimpose LCD 22 and are arranged so as to correspond to 19 focus detection areas. . Reference numerals 2230 to 2255 in FIG. 10B are 26 sets of second display index groups which are also superimposed on the superimpose LCD 22. In this embodiment, the phase difference type focus detection device 9 constituted by the line sensor 9f composed of a CCD described with reference to FIG. 2 includes line sensors corresponding to 45 focus detection areas. That is, a line sensor corresponding to a total of 45 focus detection areas including 19 of the first display index group and 26 of the second display index group in the viewfinder field described above is provided, and each focus detection is supported. The focus adjustment state is detected in the focus detection area.

In the description of FIG. 10, the first display index group and the second display index group have been described with separate drawings, but in actuality, they are configured by the same liquid crystal display device. In this embodiment, the voltage value for driving the first display index group segments 2201 to 2219 and the voltage value for driving the second display index group segments 2230 to 2255 are within the LCD drive circuit 105. The circuit is configured to be independently controllable. That is, each display index group is switched between the voltage A and the voltage B as described above, but these voltage values can be controlled independently, and can be the same or different.

FIG. 11 shows an operation flowchart of the entire camera (mainly the CPU 100) of the second embodiment having the above-described configuration. Hereinafter, the operation of the camera will be described with reference to this flowchart and FIGS. 1, 2, and 12 to 13.

First, when the photographer rotates the electronic dial to a position where SW-M is turned on, the camera power is turned on (# 400), and the CPU 100 waits until SW1 is turned on (# 401).

Next, focus detection is performed in 45 focus detection areas obtained by adding 19 focus detection areas of the first display index group and 26 focus detection areas of the second display index group in the finder field described above. Is selected (# 401a). The selection here may be changed by a parameter value stored in the EEPROM 100a attached to the CPU 100, for example.

When the focus detection area is 19 points, only the first display index group segments 2201 to 2219 are driven (# 401b). On the other hand, when the focus detection area is 45 points, both the first display index group segments 2201 to 2219 and the second display index group segments 2230 to 2255 are driven (# 401c).

Next, the CPU 100 confirms whether the SW-AFS is in the automatic focus detection area selection mode or the arbitrary focus detection area selection mode (# 402). In the automatic focus detection area selection mode, a predetermined focus detection is performed by a predetermined algorithm. An area is selected (# 403). Here too, several methods are conceivable as an algorithm for automatically selecting a focus detection area, but a near-point priority algorithm in which a weight is assigned to a central focus detection area, which is often employed in a so-called multipoint AF camera, is used. It is valid.

Further, at this stage (# 403), it is not possible to specify where the focus detection area in the finder field of view is in focus, so this mode (automatic focus detection area selection mode) is shown in FIG. In this manner, the focus detection area is not lit (display mode 1). Further, the drive voltage of the liquid crystal superimposing LCD 22 is maintained in the display mode performed by the voltage A described above in the subsequent operations.

Thereafter, the automatic focus detection circuit 103 is caused to perform a focus detection operation in the focus detection area selected here (# 408).

On the other hand, when the arbitrary focus detection region selection mode is set in # 402, the display index corresponding to the selected focus detection region is superimposed on the viewfinder field (display mode 2) (# 404).

Here, when the 19 focus detection areas of # 401b are selected, the display in the viewfinder field is as shown in FIG. That is, the drive voltage of the first display index group segments 2201 to 2219 of the LCD 22 for liquid crystal superimpose is changed to the display mode performed by the voltage B described above.

On the other hand, when the 45-point focus detection area of # 401c is selected, the display in the viewfinder field is as shown in FIG. That is, the drive voltages of the first display index group segments 2201 to 2219 and the second display index group segments 2230 to 2255 of the LCD 22 for liquid crystal superimpose are changed to the display mode performed by the voltage B described above.

Further, if any of the focus detection area movement instruction switches (SW-T, SW-B, SW-L, SW-R) is pressed, the focus detection area is moved to the segment position of the corresponding focus detection area. And display (# 405).

When the 19-point focus detection area # 401b is selected, for example, when the focus detection area movement instruction switch SW-L is pressed twice, as shown in FIG. An area 2208 is displayed as a lighting segment of the arbitrary focus detection area. The other 18 points of the focus detection areas 2201 to 2207 and 2209 to 2219 are in a state in which the focus detection area is thinly displayed as a selectable focus detection area, although it is in a non-lighting segment state.

On the other hand, when the 45-point focus detection area of # 401c is selected, the following is performed. For example, when the focus detection area movement instruction switch SW-L is pressed five times, the focus detection area 2208 is displayed as a lighting segment that is an arbitrary focus detection area, as shown in FIG. The other 18 points of the focus detection areas 2201 to 2207 and 2209 to 2219 and 26 points of 2230 to 2255 are in a state in which the focus detection area is thinly displayed as a selectable focus detection area although it is in a non-lighting segment state. .

Further, the driving voltage of the liquid crystal superimposing LCD 22 is maintained in the subsequent display mode in which the corresponding display segment group is performed by the voltage B described above.

Note that the focus detection area movement instruction of # 405 can be interrupted by an AND condition where the state determination (# 406) of the next focus detection area selection mode is ON and SW1 is ON. It is.

Next, the state of the focus detection area selection mode change switch (SW-AFD) is determined (# 406). In the description of the present embodiment, the physical switch state is determined. However, for example, it may be changed by a parameter value stored in the EEPROM 100a attached to the CPU 100. When the focus detection area selection mode change switch is in the ON state, the automatic focus detection circuit 103 is caused to perform the focus detection operation in the selected focus detection area while maintaining the display form described in # 404 ( # 408).

When the focus detection area selection mode change switch is in the OFF state, only the display index corresponding to the focus detection area selected in # 406 is displayed as a superimposed segment in the viewfinder field (display mode 3). (# 407).

At this time, the driving voltage of the liquid crystal superimposing LCD 22 is changed to the display form performed by the voltage A described above for the corresponding display segment group, so the display in the viewfinder field here is shown in FIG. It becomes like. That is, the focus detection area 2208 is displayed as a lighting segment of the arbitrary focus detection area.

On the other hand, 44 points including 18 points of other focus detection areas 2201 to 2209 and 2221 to 2219 or 26 points of 2230 to 2255 cannot be visually recognized as non-lighting segment states as non-selectable focus detection areas. In the subsequent operations, this display form is maintained.

In the subsequent display modes, the aforementioned display state is maintained until the state of the focus detection area selection mode change switch (SW-AFD) is changed to the ON state.

Next, the automatic focus detection circuit 103 is caused to perform a focus detection operation in the selected focus detection region (# 408). When the focus detection operation by the automatic focus detection circuit 103 is performed, the CPU 100 determines whether or not the selected focus detection region is a region where focus detection is impossible (# 409). If not possible, the CPU 100 sends a signal to the LCD drive circuit 105 to cause a focus mark (not shown) of the LCD 27 in the viewfinder to blink. Thus, the photographer is warned that focus detection is impossible (# 410), and this operation is continued until SW1 is turned off (# 411).

If the selected focus detection area is an area where focus detection is possible, and the focus adjustment state in this focus detection area is not in focus (# 412), the CPU 100 sends a signal to the lens focus adjustment circuit 110 to send a photographic lens 3. Is driven in focus (# 413). After driving the lens, the automatic focus detection circuit 103 performs focus detection again (# 408), and determines whether or not the focus detection area is in focus (# 412). When the focus of the focus detection area is obtained, the CPU 100 sends a signal to the LCD drive circuit 105 to light a focus mark (not shown) of the LCD 27 in the finder.

In the automatic focus detection area selection mode, as shown in FIG. 13A, the focus detection area (for example, 2208) corresponding to the automatically selected focus detection area is lit up with high brightness for a moment. The user is in focus (# 414).

Here, when 19 focus detection areas of # 401b are selected, and further in the arbitrary focus detection area selection mode and the focus detection area selection mode change switch is ON, the result is as shown in FIG. . That is, the focus detection area 2208 displayed as the arbitrary focus detection area is lit with high brightness for a moment to notify the photographer that focus is achieved (# 414). At this time, the focus detection area movement instruction of # 405 described above can be performed as an interrupt operation. Therefore, 18 points of other focus detection areas 2201 to 2207 and 2209 to 2219 are thin focus detection areas although they are in a non-illuminated segment state as a focus detection area that can be selectively moved by a photographer's focus detection area movement instruction operation. It will be displayed.

On the other hand, when the 45-point focus detection area of # 401b is selected, and further in the arbitrary focus detection area selection mode and the focus detection area selection mode change switch is ON, the result is as shown in FIG. That is, the focus detection area 2208 displayed as the arbitrary focus detection area is lit with high brightness for a moment to notify the photographer that the camera is in focus (# 414). At this time, the focus detection area movement instruction of # 405 described above can be performed as an interrupt operation. Accordingly, 44 points of 18 points of other focus detection regions 2201 to 2207 and 2209 to 2219 and 26 points of 2230 to 2255 are selected as a focus detection region that can be selectively moved by a focus detection region movement instruction operation in the state of a non-lighting segment. Although there is, it is displayed lightly.

Further, in the arbitrary focus detection area selection mode and when the focus detection area selection mode change switch is OFF, the same display as in FIG.

The subsequent operations are the same as those described in FIG.

According to the present embodiment, the display area of the focus detection area that can be selectively moved and the focus detection area that cannot be selectively moved are divided into a plurality of groups (two in this case), and each has a different voltage. To drive. As a result, even in a camera having a larger number of autofocus focus detection areas, display can be limited to only a focus detection area that can be selectively moved. Therefore, the focus detection area that cannot be selected is not displayed, and a finder with less distraction when observing the subject is realized.

The figure which shows schematic structure of the single-lens reflex camera which is an Example of this invention. The figure which shows the structure of the electric circuit incorporated in the single-lens reflex camera which is an Example of this invention. The figure which shows the structure in the visual field of the finder which is 1st Example of this invention. FIG. 3 is an explanatory diagram illustrating a relationship between a segment density and a bias voltage of a liquid crystal display device that is an embodiment of the present invention. The figure which shows the structure in the visual field of the finder which is 1st Example of this invention. 3 is a flowchart showing the operation of the single-lens reflex camera according to the first embodiment of the present invention. Explanatory drawing which shows the display form showing selection of the focus detection area | region in the finder visual field which is 1st Example of this invention. Explanatory drawing which shows the display form of the focusing state in the finder visual field which is 1st Example of this invention. The figure explaining the focus detection operation | movement of the phase difference detection system in the Example of this invention. The figure which shows the structure in the visual field of the finder which is 2nd Example of this invention. 9 is a flowchart showing the operation of a single-lens reflex camera that is a second embodiment of the present invention. Explanatory drawing which shows the display form showing selection of the focus detection area | region in the finder visual field which is 2nd Example of this invention. Explanatory drawing which shows the display form of the focusing state in the finder visual field which is 2nd Example of this invention.

Explanation of symbols

10 Focusing screen 13 Erect image forming member (Pentadaha prism)
14a, 14b Reflective surface 16 Eyepiece optical member 20 Light emitting element 22 Liquid crystal display device 2201-2221, 2230-2255 Measurement region (segment, focus detection region, side light region)
2201 to 2219 First measurement area 2230 to 2255 Second measurement area SW-AFD Measurement area selection mode changing means SW-T, SW-B, SW-L, SW-R, SW-DIAL1, SW-DIAL2 Measurement area Movement instruction member

Claims (4)

A transmissive liquid crystal display device that displays a plurality of measurement areas superimposed on a subject image;
Among the plurality of measurement areas, a measurement area selection mode changing means for switching between a mode in which an operation for instructing movement of a specific measurement area is possible and a mode in which the operation is impossible,
A measurement area movement instructing member for instructing movement of the selected specific measurement area in a mode by switching the measurement area selection mode changing means capable of instructing movement of the specific measurement area; and
Among the segments indicating the plurality of measurement areas of the liquid crystal display device, the segment of the selected specific measurement area is set to a first state in which a common drive voltage is applied, and the segments other than the selected specific measurement area A segment of the measurement region is set to a second state in which the common drive voltage is not applied,
In a mode in which a specific measurement region can be instructed with respect to the common driving voltage of the liquid crystal display device in a mode by switching of the measurement region selection mode changing means that cannot be instructed to move a specific measurement region. A measurement area information display device for an imaging device, wherein the common drive voltage of a liquid crystal display device is increased. A focusing screen disposed on a planned imaging plane on which at least a part of the imaging light beam is imaged in order to observe a subject image from the imaging lens;
A light emitting element disposed in the vicinity of the liquid crystal display device;
An erect image forming member disposed on an upper portion of the focusing screen;
A reflective surface provided on a part of the eyepiece optical member behind the erect image forming member,
By projecting the light beam from the light emitting element onto the reflecting surface via the liquid crystal display device, segments indicating a plurality of measurement regions of the liquid crystal display device are formed on the subject image formed on the focusing screen. The measurement area information display device for an imaging apparatus according to claim 1, wherein the measurement area information is displayed in a superimposed manner. The display unit for displaying the measurement area of the liquid crystal display device includes a first plurality of measurement areas and a plurality of second measurement areas different from the first plurality of measurement areas as the plurality of measurement areas. With
A plurality of segments indicating the first plurality of measurement regions and a plurality of segments indicating the second plurality of measurement regions can each be independently applied with a common drive voltage. The measurement area information display device for an imaging apparatus according to claim 1 or 2. The measurement area information display device for an imaging apparatus according to claim 1, 2 or 3, wherein the measurement area of the liquid crystal display device is a focus detection area or a photometry area.

Images