JP2007114641A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use auxiliary light prepared for autofocusing and built in a camera, also as display light at photographing by a self-timer mode. <P>SOLUTION: In carrying out an automatic focusing processing of a dark object, an LED 33 is turned on cooperatively with the half-depression of a shutter button 25, and the auxiliary light is condensed and projected on the object. When a self-timer button 12 is depressed and also the shutter button 25 is fully depressed, a self-timer mode starts and the LED 33 is turned on. A diffusion optical system 37 having a red diffusion film 37a is inserted in front of the LED 33, and the LED 33 is lighted with low light quantity. In seven seconds after the turning-on, the LED 33 starts to flicker, and as photographing by the self-timer mode ends, the LED 33 is turned off. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera incorporating an autofocus device that automatically focuses a photographing lens, and more particularly, illuminates a subject with auxiliary light so that a dark subject can be properly focused with the autofocus device. The present invention relates to a camera with a built-in auxiliary light projector.

  Many digital cameras using a CMOS type or CCD type image sensor focus the photographic lens while evaluating the imaging state of the subject image formed on the image sensor through the photographic lens. . The imaging signal obtained for each pixel from the image sensor is used to evaluate the imaging state. For example, the focus lens in the photographic lens system is moved so that the evaluation value obtained by integrating the signal level difference between adjacent pixels is the highest. It is adjusting.

  As described above, in the method of focusing based on the image pickup signal from the image sensor, it is difficult to focus when the subject itself has a low contrast, and the influence is great at the time of shooting at night when the subject brightness is lowered overall. . From such a background, as is known in Patent Document 1, an auxiliary light projector is incorporated in a camera, and auxiliary light is projected toward a subject when focusing is performed by an autofocus device. This focusing and auxiliary light projection work when the shutter button is half-pressed, and then when the shutter button is fully pressed, the auxiliary light is turned off, but shooting is performed in focus. .

  On the other hand, the digital camera is provided with a self-timer button so that shooting in the self-timer mode is possible. When the self-timer button is operated and the shutter button is fully pressed, the shutter is automatically operated after a predetermined time has elapsed, and photographing is performed. A display for a self-timer that is lit and flashing is provided so that the timing at which the shutter operates can be visually recognized by the person who is the subject. For example, when the shutter button is fully pressed in the self-timer mode, the display is It is turned on, and blinking is started after several seconds, and it is informed that the shutter is operated and photographing is performed several seconds later.

The lighting / flashing of the display may be difficult to be visually recognized if the person who is the subject is located slightly far from the digital camera. For this reason, power may be wasted by increasing the light quantity of the display. In order to avoid this, a method for improving visibility and reducing power consumption as proposed in Patent Document 2 has been proposed.
JP 2003-98579 A JP-A-8-18832

  However, the operation of focusing and the operation of shooting in the cell timer mode are not necessarily synchronized, and the auxiliary light operates only when focusing, and the display operates only in the self-timer mode. Therefore, the provision of the two types of auxiliary illumination mechanisms for almost independent operation tends to consume electric power and is also structurally complicated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a digital camera in which an auxiliary light projector that operates at the time of focusing is also used as a display at the time of photographing in the self-timer mode.

  In order to achieve the above-mentioned object, the present invention provides an auxiliary light projector for autofocus that is built into the camera so that even a dark subject can be focused. Then, it is also used as a display that lights up and flashes. In particular, when operating as a display, it is more effective to reduce power consumption by turning on and blinking at a lower light intensity than when operating the shutter halfway as an auxiliary light projector for autofocus. is there.

  In addition, a color filter that can be freely inserted and removed is provided on the front surface of the auxiliary light projector, and the color of the auxiliary light when the shutter is half-pressed during focusing and the display when the shutter is fully pressed when photographing in the self-timer mode The color of the display light is made different, and a condensing optical system and a diffusing optical system that can be taken in and out are provided on the front surface of the auxiliary light projector, and when operating as auxiliary light at the time of focusing, the light is condensed. When the auxiliary light is focused toward the subject by the optical system and operated as a display during shooting in the self-timer mode, the display light is diffused by the diffusion optical system so that it can be easily seen by the difference in color and light collection. This is also effective in carrying out the present invention.

  The auxiliary light projector that is turned on during auto-focusing is also used as a display for shooting in the self-timer mode. When operating as a display, it is operated with a lower light intensity than when operating as auxiliary light. Since there is a difference in the color of the light projected and how it is condensed in the case of the display, power consumption is reduced compared to a conventional camera with a separate auxiliary light projector and display. The display can be easily seen, and the structure of the camera can be simplified.

  In FIGS. 1 and 2, which respectively show the front and rear appearances of a digital camera using the present invention, a retractable photographic lens 3 is incorporated in the body 2 and protrudes to the illustrated position when in use, and the body when not in use. 2 can be accommodated. The front surface of the body 2 is further provided with a light emission window 4 of the flash device, an objective window 5 of the optical viewfinder, and an auxiliary light window 6 for irradiating the subject with auxiliary light when the autofocus device is operated under dark conditions such as nighttime. Yes.

  On the back of the body 2, a display panel 8 such as a liquid crystal display panel or an EL display panel is incorporated, and an operation panel 9 provided with various operation buttons including a cross key and an eyepiece window 10 of an optical viewfinder are provided. . A shutter button 25 and a self-timer button 12 that is pressed when photographing in the self-timer mode are provided on the upper portion of the body 2.

  In FIG. 3 which shows the outline of the electrical configuration of this digital camera, the system controller 14 controls the sequence of the entire digital camera and controls the operation of each circuit section to be described later. A CCD-type or CMOS-type image sensor 15 is provided behind the photographic lens 3, and converts the subject image formed on the photocathode into an electrical signal and outputs it. Imaging signals sequentially obtained from the image sensor 15 are amplified by the preamplifier 16 and then digitally converted by the AD converter 17. The digitized image data is subjected to well-known image processing by the image data processing circuit 18 and is written into the DRAM 20 via the bus line 19. On the DRAM 20, the image data for one screen sequentially input is sequentially updated, the updated image data is read one after another, and a through image is displayed on the display panel 8 via the display driver 21.

  Image data from the image data processing circuit 18 is also input to the AF processing circuit 23 and the AE processing circuit 24. The AF processing circuit 23 is based on the image data sequentially input from the image data processing circuit 18 when the shutter button 25 (see FIG. 1) is half-pressed, for example, a difference in luminance component for each adjacent pixel. Are extracted and integrated for one screen to calculate an AF evaluation value. The system controller 14 drives the AF motor 27 via the driver 26 to move the photographing lens 3 in the optical axis direction so that the AF evaluation value input in this way becomes the highest. The photographic lens 3 is feedback controlled so as to stop at the position where the AF evaluation value is highest, and the photographic lens 3 is automatically focused by a so-called contrast method.

  The AE processing circuit 24 measures the average luminance of one entire screen based on the image data from the image data processing circuit 18 and determines whether or not the photometric value is within an appropriate level range. When the photometric value is not within the appropriate level range, the sensor driver 29 controls the charge accumulation time of the image sensor 15. Of course, when the aperture device is incorporated in the photographing lens 3, the aperture control and the accumulation time control may be performed in parallel. In addition to the photometry method, not only the average photometry of the entire screen, but also a multi-area photometry method that divides the screen into a plurality of areas and performs appropriate weighting to calculate the photometric value. Further, when the subject is dark such that an appropriate level cannot be obtained only by controlling the aperture and the charge accumulation time, the flash photographing using the flash device 30 is automatically switched.

By the way, when attempting to shoot a dark subject that requires flash shooting, the contrast of the subject is low and an AF evaluation value of a sufficient level cannot often be obtained from the AF processing circuit 23. For this reason, when the shutter button 25 is half-pressed and the subject brightness is detected to be below a predetermined level, the system controller 14 is incorporated as an auxiliary light emitter in the back of the auxiliary light window 6 via the LED driver 32. The white LED 33 is turned on, and AF auxiliary light is projected toward the subject.

  An illumination optical device 35 is provided between the LED 33 and the auxiliary light window 6. The illumination optical device 35 includes two types of optical systems, a condensing optical system 36 and a diffusing optical system 37, and a red diffusing film 37 a is incorporated in the diffusing optical system 37. One of them is positioned in front of the LED 33 via the illumination switching driver 38 and the switching motor 39 in accordance with a command from the system controller 14. As shown in FIG. 4, when the condensing optical system 36 is selected, the light projection pattern 40 is irradiated toward the subject by the reticle 36a and the light projection lens 36b having a light condensing function. As shown in FIG. 5, the projection pattern 40 becomes a narrow beam S1 projected toward a narrow range of the subject, and the AF process is performed based on the projection pattern 40 irradiated on the subject.

  As described above, when the shutter button 25 is half-pressed to complete the AE process and the AF process, the full-press operation of the shutter button 25 is permitted, and the still image shooting process is performed after the full-press operation of the shutter button 25. . When the shutter button 25 is fully pressed, the LED 33 that has been lit when the AF auxiliary light is projected is turned off, and the image sensor 15 accumulates signal charges in the charge accumulation time determined by the AE process. The flash device 30 emits light in synchronization with the start of signal charge accumulation, and auxiliary illumination light is emitted from the light emission window 4 toward the subject. Of course, when the subject brightness exceeds a predetermined level, the AF auxiliary light is not projected at the time of focusing, and the flash device 30 at the time of photographing is not emitted. When the accumulation of signal charges is completed, an image pickup signal is taken from the image sensor 27. The obtained imaging signal is input to the bus line 19 as image data for one screen from the image data processing circuit 18, temporarily stored in the DRAM 20, and then recorded on the removable memory card 42 under the control of the system controller 14. The

  When the self-timer button 12 provided on the upper portion of the body 2 is pressed, the system controller 14 recognizes that the self-timer mode is set. Since the autofocus function operates even when the self-timer mode is set, the LED 33 is turned on when the subject brightness is below a predetermined level when the shutter button 25 is half-pressed, and the condensed light S1 shown in FIG. The AF auxiliary light is projected toward the subject. If the subject brightness is above a predetermined level, it does not light up. Subsequently, when the shutter button 25 is fully pressed, the diffusion optical system 37 moves to the front surface of the LED 33 by the operation of the illumination switching driver 38 and the switching motor 39. At the same time, the self-timer mode is started and the LED 33 is turned on. Since the diffusing optical system 37 is composed of a red diffusing film 37a and a diverging illumination lens 37b, the white light from the LED 33 becomes a diffused red diffused light S2 having a spread as shown in FIG. It is turned on and becomes display light that can be easily visually recognized by a person relatively far from the camera. The LED driver 32 also functions as a control means for changing the drive current of the LED 33 to increase or decrease the light emission amount of the LED 33. When the shutter button 25 is fully pressed after the self-timer button 12 is pressed as described above, In response to this, when the system controller 14 operates the LED driver 32, a light amount down command is also input. As a result, the LED 33 emits light darker than when the AF auxiliary light is projected.

  When the self-timer button 12 is pressed and the shutter button 25 is fully pressed, the self-timer mode is started. For example, the shutter is set to be photographed after 10 seconds. Synchronously with this, the LED driver 32 is activated in the cell timer mode, and the LED 33 starts to be lit as described above. At the same time, the timer 13 is activated to start timing. For example, when 7 seconds elapse, the LED 33 is blinked. Three seconds after the start of blinking, the shutter is activated to complete the photographing, and the LED 33 is also turned off and the self-timer mode ends.

  The operation of the above configuration will be described below with reference to the flowchart of FIG. When the shutter button 25 is half-pressed regardless of whether or not the self-timer button 12 is pressed, an autofocus process is executed in a normal sequence, and the condensing optical system 36 is positioned in front of the LED 33. If the subject brightness is below a predetermined level, the white light from the LED 33 is used as AF auxiliary light. When used as AF auxiliary light, since the condensing optical system 36 has a condensing function, the light projection pattern 40 can be irradiated to the subject. When the AF process ends, the LED 33 is turned off. Of course, if the subject brightness is equal to or higher than a predetermined level, the AF auxiliary light is not turned on.

  When the AF process is completed, the shutter button 25 can be fully pressed. If the self-timer button 12 is already pressed, when the shutter button 25 is fully pressed, the system controller 14 recognizes that it is in the self-timer mode, the timer 13 is started, and the diffusion optical system 37 is placed on the front surface of the LED 33. Inserted into. At the same time, a process of reducing the light amount of the LED 33 is performed, and lighting in the self-timer mode is started. Since the diffusion optical system 37 includes a red diffusion film 37a and an illumination lens 37b having a diverging action, white light from the LED 33 is red diffused light S2. When the self-timer mode is set, for example, the shutter is activated 10 seconds after the shutter button 25 is fully pressed, and photographing is performed. In synchronization with this, for example, when the timer 13 counts 7 seconds, the LED 33 changes from lighting to blinking. When the flashing starts and the time measured by the timer 13 elapses for 3 seconds, the shutter is activated to complete the photographing in the self-timer mode, the LED 33 is turned off, and the self-timer mode is reset.

  As mentioned above, although it demonstrated according to embodiment shown in figure, when implementing this invention, a various change is possible. For example, although the red diffusion film 37a is used for the diffusion optical system 37, the irradiation range of the illumination light from the LED 33 may be widened by a combination of a red filter and an illumination lens 37b. In addition, the color filter is not limited to red, but may be any color that can be confirmed from a distance. Further, although the condensing optical system 36 and the diffusing optical system 37 are provided independently, the illumination range is expanded by moving some or all of the lenses constituting the condensing optical system 36 in the optical axis direction. In this case, the illumination range can be easily switched between wide and narrow in conjunction with the mechanical movement of the self-timer button 12 or the light emission knob.

It is a perspective view which shows the front side external appearance of the camera using this invention. It is a perspective view which shows the back side external appearance of the camera using this invention. It is a block diagram which shows the outline of the electrical structure of the camera using this invention. It is a perspective view which shows the illumination optical apparatus used for this invention. It is operation | movement explanatory drawing when the illumination optical apparatus is switched. It is a flowchart which shows the process of self-timer mode.

Explanation of symbols

2 Camera body 6 Auxiliary light window 12 Self-timer button 13 Timer 35 Illumination optical device 36 Condensing optical system 37 Diffusion optical system S1 Narrow beam S2 Diffuse illumination light

Claims (3)

In a camera equipped with an auxiliary light projector that projects auxiliary light toward the subject in conjunction with a half-pressing operation of the shutter button when focusing the photographing lens using an autofocus device,
When the shutter button is fully pressed when the self-timer mode is set, the auxiliary light projector is lit or blinks at a lower light intensity than when the shutter button is half-pressed, and the timing at which self-timer shooting is performed is set. A digital camera that is also used as a display for display.   A color filter is provided on the front surface of the auxiliary light projector so as to freely enter and exit, and when the self-timer mode is set, the projection color when the shutter button is half-pressed and the display color when the shutter button is fully pressed are changed. The digital camera according to claim 1.   A condensing optical system and a diffusion optical system are provided on the front surface of the auxiliary light projector so as to be switchable. When the self-timer mode is set, auxiliary light that is condensed toward the subject is projected when the shutter button is half-pressed, and the shutter 3. The digital camera according to claim 1, wherein display light that diverges toward the subject is emitted when the button is fully pressed.

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