JP4798654B2 - Digital camera - Google Patents

Description

  The present invention relates to a digital camera, and more particularly to an improvement of a digital camera capable of displaying an image being observed and an image being shot on a display screen.

2. Description of the Related Art Conventionally, a camera that subjects a subject image formed by a photographing optical system such as a photographing lens to photoelectric conversion by an image sensor and displays it on an image display device such as a liquid crystal monitor based on an image signal obtained thereby is generally used. (See, for example, Patent Document 1).
In addition, in an electronic camera device having a plurality of image pickup devices, one image pickup device is used for recording a still image, and the other image pickup device is used for display on the above-described liquid crystal monitor or the like. (For example, refer to Patent Document 2).
JP 2003-330082 A JP 2001-111880 A

  By the way, a camera that performs so-called through image display, in which imaging is repeatedly performed by an image sensor and a substantially real-time moving image is displayed on a display device has been developed in recent years.

  However, since the digital single-lens reflex camera described in Patent Document 1 described above captures and captures an image on the CCD by raising the quick return mirror, the CCD can capture an image when the mirror is down. Can not. Therefore, a through image (almost real-time moving image (live view image)) cannot be displayed on the display device.

  Accordingly, an object of the present invention is to provide a digital camera capable of realizing a through image display using two image sensors in a digital single-lens reflex camera.

That is, the invention according to claim 1 is an imaging optical system, a main mirror that transmits and reflects a subject light beam that has passed through the photographing optical system, and an observation image of a screen on which the subject light beam reflected by the main mirror is imaged. An observation optical system that conducts observation through a prism through a finder window, and a first imaging unit that generates first image data based on the subject luminous flux in a state where the main mirror is retracted from the photographing optical path. A state in which the main mirror is not retracted from the photographing optical path and the observation image is guided to the finder window, provided at any position of the prism that is off the optical axis of the observation optical system. The second imaging means for generating the second image data based on the observation image guided by the prism, and the first imaging means or the second imaging means. Display means for displaying the subject image based on the generated image data, a first control means comprising an application specific integrated circuit including a CPU for controlling the driving of the first imaging means, the second imaging And a second control means comprising an application specific integrated circuit including a CPU different from the CPU for controlling the driving of the means.

  According to the present invention, in a digital single-lens reflex camera, a digital camera capable of realizing a through image display using two imaging elements can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a first embodiment of the present invention and is an external perspective view showing a configuration of a single-lens reflex digital camera.

In FIG. 1, this single-lens reflex digital camera (hereinafter abbreviated as “camera”) 1 is mainly composed of a lens barrel 10 as an interchangeable lens and a camera body 20. A desired lens barrel 10 is detachably set with respect to the front surface.
On the upper surface of the camera body 20, a release button 21, a mode dial 22, a power switch lever 23, a control dial 24, and the like are provided.

  The release button 21 is a button for executing a shooting preparation operation and an exposure operation. The release button 21 is composed of a two-stage switch of a first release switch and a second release switch. When the release button 21 is pressed halfway, the first release switch is turned on to perform photometric processing or Shooting preparation operations such as distance measurement processing are executed. Further, when the release button 21 is fully pressed, the second release switch is turned on and the exposure operation is executed.

  The mode dial 22 is an operation member for setting a shooting mode at the time of shooting. When the mode dial 22 is rotated in a predetermined direction, a shooting mode at the time of shooting is set. The power switch lever 23 is an operation member for turning on / off the power of the camera 1. By turning the power switch lever 23, the main power supply of the camera 1 is switched on / off.

  The control dial 24 is a member for setting shooting information. By operating the control dial 24, various settings are performed during shooting.

  On the rear surface of the body unit 20, a liquid crystal monitor 26 for displaying a photographed image, a menu, and the like, a playback button 27, a menu button 28, a cross key 30, an OK button 31, and an eyepiece optical system finder 33. Etc. are arranged.

  The playback button 27 is a button for switching the operation mode of the camera 1 to a playback mode in which an image can be played back from a JPEG file recorded on an SDRAM 62 or a recording medium 63 described later. The menu button 28 is a button for displaying a menu screen on the liquid crystal monitor 26. This menu screen is composed of menu items having a plurality of hierarchical structures. The user can select a desired menu item with the cross key 30 and can determine the item selected with the OK button 31.

  FIG. 2 is a block diagram showing a schematic system configuration of the camera according to the first embodiment of the present invention.

  In FIG. 2, the light beam from the subject 5 is guided to the main mirror 40 in the camera body 20 through the photographing lens 12 in the lens barrel 10. The light beam reflected upward in FIG. 2 by the main mirror 40 is incident on the prism 41 constituting the finder optical system. A part of the light beam incident on the prism 41 is reflected and guided to the eyepiece lens 42, and is visually recognized by the photographer's eyes. In addition, among the light beams incident on the prism 41, the light beam that is transmitted without being reflected is imaged on the imaging surface of the through image CCD 43 as the second imaging means. An image signal (second image data) generated by being converted into an electrical signal by the through image CCD 43 is output to an analog front end unit (AFE) 44.

  The AFE 44 is for adjusting the variation in data of the through image CCD 43 and supplying imaging timing to the CCD. The AFE 44 outputs image data obtained from the through-image CCD 43 to the ASIC 55a under the control of an application-specific integrated circuit (hereinafter abbreviated as ASIC) 55a. The configuration and functions of the AFE 51 described later are the same as those of the AFE 44.

  The ASIC 55a has both a function as a second control unit and a function as a control unit of a peripheral circuit. In this case, the ASIC 55a controls the AFE 44, the flash memory (Flash Memory) 57a, the TFT liquid crystal driver 59, the SDRAM 62a, and the like.

  The main mirror 40 is provided so as to be rotatable about the shaft 40a in the direction of the arrow A in the figure, and a part thereof is constituted by a half mirror. The light beam incident on the main mirror 40 and transmitted through the half mirror part is reflected on the optical axis of the photographing lens 12 by the sub-mirror 47 provided behind the main mirror 40 (on the right side in FIG. 2). / AE sensor unit 48. The AF / AE sensor unit 48 is for performing automatic ranging and photometry of the camera.

  The main mirror 40 is located in the photographing optical path as shown in the figure when observing the subject, but rotates upward about the shaft 40a and moves to a position retracted from the photographing optical path (not shown) during the photographing. To do. At this time, the sub mirror 47 is folded and moved to the retracted position together with the main mirror 40. In other words, since the main mirror 40 and the sub mirror 47 are in the retracted position at the time of photographing, the light flux from the subject 5 that has passed through the photographing lens 12 is coupled onto the imaging surface of the main (Main) CCD 50 that is the first imaging means. Imaged. An image signal (first image data) generated by being converted into an electric signal by the main CCD 50 is output to an ASIC 55b described later via an analog front end unit (AFE) 51.

  The ASIC 55b has both a function as a first control unit and a function as a control unit of a peripheral circuit. In this case, the ASIC 55b controls the photographing lens 12, the main mirror 40, the AF / AE sensor unit 48, the AFE 51, the flash memory 57b, the TFT liquid crystal driver 59, the SDRAM 62b, the recording medium (Media) 63, and the like.

  The ASIC 55b includes the above-described photographing lens 12, main mirror 40, AF / AE sensor unit 48, AFE 51, flash memory 57b, TFT liquid crystal driver 59, liquid crystal monitor (TFT) 26, SDRAM 62b, recording medium 63, The switch (SW) unit 64 is connected to the ASIC 55a described above.

  The photographic lens 12 is moved in the optical axis direction based on the driving amount calculated in the ASIC 55b from the result obtained by the AF / AE sensor unit 48. Further, the main mirror 40 and the sub mirror 47 are moved to the observation position and the retracted position at a predetermined timing under the control of the ASIC 55b.

  The flash memories 57a and 57b, the SDRAMs 62a and 62b, and the recording medium 63 are provided as storage areas of the camera 1. For example, the flash memories 57a and 57b store codes for operating the camera, menu settings, adjustment data, and the like. The SDRAMs 62a and 62b are used as buffers for image data processing and temporary storage. Further, the recording medium 63 is an external recording medium such as various memory cards and an external hard disk drive (HDD) that can be attached to and detached from the camera body 20 via a camera interface (not shown).

  The TFT liquid crystal driver 59 is for driving the liquid crystal monitor 26, and displays specified data and images on the liquid crystal monitor 26 according to the control of the ASIC 55a or 55b.

  The switch unit 64 includes various buttons and switches such as the release button 21, the menu button 28, and the OK button 31 described above.

  FIG. 3 is a block diagram showing the configuration of the ASIC 55a shown in FIG. 2 and its peripheral part.

  The ASIC 55a has a main CPU 70a. An input / output unit (Global Input / Output; GIO) 71a and a flash memory interface (Flash Memory Interface; FMI) 72a corresponding to the flash memory 57a are connected to the CPU 70a.

  The timing of the CCD block (CCD block) 45 is controlled from the CPU 70a in the ASIC 55a via the input / output unit 71a, and output image data from the through image CCD 43 is taken into the ASIC 55a according to this timing. ing. The CCD block 45 includes the through image CCD 43 and the AFE 44 shown in FIG.

  The CPU 70a also controls the following units. That is, a CCD interface (CCD I / F) 80a, a preprocessor (Pre Pro) 81a, an image processor (Image Processor) 82a, a JPEG circuit 83a, a media controller (MediaC) 85a, an external bus (EXTBUS) 88a, The SDRAM controller (SDRAMC) 89a and the video controller (VideoC) 90a are controlled by the CPU 70a. The preprocessor 81a, the image processor 82a, the JPEG circuit 83a, the media controller 85a, the external bus 88a, the SDRAM controller 89a, the video controller 90a, and the flash memory interface 72a are connected to each other by an internal bus 75a.

  The CCD interface 80 a is for taking in image data supplied from the CCD block 45. The preprocessor 81a is for performing preprocessing of image data supplied from the CCD interface 80a, for example, correcting defects. The image processor 82a is for performing image processing such as white balance and image resizing, for example. The JPEG circuit 83a performs JPEG conversion of image data together with the image processor 82a.

  The media controller 85a is for controlling a recording medium (not shown). The external bus 88a is for controlling the driving unit 13 of each part of the lens and the mechanical system including the above-described photographing lens 12. Similarly, the SDRAM controller 89a controls data to the SDRAM 62a, and the video controller 90a controls driving of the TFT block 60 composed of the TFT liquid crystal driver 59 and the liquid crystal monitor 26.

  FIG. 4 is a block diagram showing the configuration of the ASIC 55b shown in FIG. 2 and its peripheral part.

  The configuration and operation of the ASIC 55b shown in FIG. 4 are basically the same as those of the ASIC 55a shown in FIG. 3 described above. Omitted, only the different configuration and operation will be described.

  The timing of the CCD block (CCD block) 52 is controlled from the CPU 70b in the ASIC 55b via the input / output unit 71b, and output image data from the main CCD 50 is taken into the ASIC 55b according to this timing. . The CCD block 52 includes the main CCD 50 and the AFE 51 shown in FIG.

  The CCD interface 80b is for capturing image data supplied from the CCD block 52. The media controller 85b is for controlling the recording medium 63 described above.

  In such a configuration, a through image capturing timing is output from the CPU 70a to the CCD block 45 via the input / output unit 71a. When the image captured by the CCD block 45 is captured into the ASIC 55a via the CCD interface 80a, preprocessing such as defect correction is performed by the preprocessor 81a. Then, the data is temporarily stored in the SDRAM 62a through the SDRAM controller 89a. Next, the data is transferred again from the SDRAM 62a to the image processor 82a via the SDRAM controller 89a, where predetermined image processing is performed together with the JPEG circuit 83a. Thereafter, the data is stored in the SDRAM 62a from the SDRAM controller 89a.

  On the other hand, the imaging timing of the main CCD is output from the CPU 70b to the CCD block 52 via the input / output unit 71b. When the image captured by the CCD block 52 (main CCD 50) is captured into the ASIC 55b via the CCD interface 80b, preprocessing is performed by the preprocessor 81b. Then, the data is temporarily stored in the SDRAM 62b through the SDRAM controller 89b. Next, the data is transferred again from the SDRAM 62b to the image processor 82a via the SDRAM controller 89b, where predetermined image processing is performed together with the JPEG circuit 83b. Thereafter, the data is stored in the SDRAM 62b from the SDRAM controller 89b. Further, the image stored in the SDRAM 62b is written to the recording medium 63 from the SDRAM controller 89b and the internal bus 75b via the media controller 85b.

  In addition, a REC view (Rec. View) image, which is an image subjected to predetermined image processing by the image processor 82b, is displayed on the liquid crystal monitor 26 constituting the TFT block 60 via the video controller 90b.

  Note that when the moving image data captured by the through image CCD 43 is written to the recording medium 63, the data is written from the ASIC 55a to the ASIC 55b. However, by providing a line for transmitting moving image data directly from the ASIC 55a to the recording medium 63, it is possible to directly write moving image data from the ASIC 55a to the recording medium 63 without passing through the ASIC 55b. By configuring in this way, higher speed processing can be realized.

  Next, the operation of the through image mode of the camera according to the first embodiment of the present invention will be described with reference to the flowchart of FIG.

  When the routine for the live view mode is entered from the camera main routine (not shown), first, in step S1, the power of the live view CCD 43 is turned on by an instruction from the CPU 70a. Next, in step S2, a frame rate for operating the through image CCD 43 is initialized by the CPU 70a. Here, for example, “30 frames / sec” is set. In step S3, the CPU 70a instructs the start of through image display.

  Next, in step S4, the CPU 70b determines whether or not the first release switch of the release button 21, that is, the two-stage release switch is half-pressed. If the first release switch is not turned on, the process proceeds to step S5, and the CPU 70b determines whether or not the mode has been changed. As a result, if the mode has not been changed, the process proceeds to step S4, and the state of the first release switch is determined again. On the other hand, when the mode is changed, that is, when the mode is changed to a mode other than the through image mode, the process exits from this routine and returns to the main routine (not shown).

  If the first release switch is turned on in step S4, the process proceeds to step S6, and the power of the main CCD 50 is turned on by an instruction from the CPU 70b. In the subsequent step S7, photometry and exposure calculation are performed on the subject 5 by the AF / AE sensor unit 48 and the CPU 70b. Subsequently, in step S8, ranging and focus adjustment are executed by the AF / AE sensor unit 48, the drive unit 13, and the CPU 70b. As described above, in steps S7 and S8, the CPU 70b executes predetermined arithmetic processing (AE, AF).

  Thereafter, in step S9, the CPU 70b determines whether or not the second release switch of the release button 21, that is, the two-stage release switch is fully pressed. If the second release switch is not turned on, the process proceeds to step S10, and the state of the first release switch is determined by the CPU 70b. As a result, if the first release switch is on, the process proceeds to step S9. If not, the process proceeds to step S4, and the subsequent processing operations are performed.

  If the second release switch is turned on in step S9, the process proceeds to step S11 and the end of the through image display is instructed by the CPU 70a. Thereafter, the process proceeds to step S12, and the power of the through image CCD 43 is turned off by an instruction from the CPU 70a. Subsequently, in step S13, the CPU 70b instructs the drive unit 13 to move (mirror up) the main mirror 40 from the photographing optical path to a retracted position (not shown). Next, in step S14, the CPU 70b performs an imaging operation by the main CCD 50. When the imaging operation is completed, in step S15, the CPU 70b instructs the main mirror 40 that has been moved to the retracted position to be moved again to the observation position in the imaging optical path (mirror down) by the drive unit 13. .

  In step S16, the CPU 70b instructs to read out image data corresponding to the image captured in the main CCD 50 in step S14. Further, in step S17, the power of the through image CCD 43 is turned on by an instruction from the CPU 70a. In step S18, when the reading of the image data corresponding to the image captured by the main CCD 50 according to the instruction from the CPU 70b is completed, in step S19, after performing predetermined image processing such as JPEG compression, the above image is displayed. The CPU 70b instructs to start a data writing operation on the recording medium 63. At the same time, the REC view process is executed so that the captured image is displayed on the liquid crystal monitor 26. Thereafter, the process proceeds to step S2.

  As described above, according to the present embodiment, the through-image CCD 43 and the photographing main CCD 50 are provided with the dedicated ASIC 55a and ASIC 55b, respectively, and the images captured by the respective CCDs are displayed on the liquid crystal monitor 26. Therefore, a through image display can be realized even with a digital single lens reflex camera.

  Further, since the dedicated ASIC 55a and the ASIC 55b are respectively provided in the through image CCD 43 and the photographing main CCD 50, the through image sequence and the photographing sequence can be controlled independently, and the CPUs 70a and 70b have a high load. The processing can be performed without applying.

  In the first embodiment described above, the example in which the first and second imaging means are constituted by CCDs has been described. However, the present invention is not limited to this, and may be constituted by an imaging element such as a CMOS. Of course.

  Furthermore, in the first embodiment described above, AF / AE is performed by the AF / AE sensor unit 48, and when the sensor is used, calculation is performed by the ASIC 55b, and only the result is transferred to the ASIC 55b. However, regarding AF / AE, the through image CCD 43 may be used without using the AF / AE sensor 48.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  In the first embodiment described above, the incident light beam reflected by the main mirror 40 includes the light beam reflected by the prism 41 on the eyepiece lens 42, and the right side that has passed through the prism 41 on the through image CCD 43. However, the present invention is not limited to this. In the second embodiment, the incident light beam that has passed through the prism is guided to the finder window and the through image CCD with almost no attenuation.

  FIG. 6 is a block diagram showing a schematic system configuration of a camera according to the second embodiment of the present invention.

  The basic configuration of the camera in the second embodiment is the same as that of the first embodiment shown in FIGS. 1 to 5, and the basic shooting operation is also the same. Therefore, for these configurations and operations, the same reference numerals are assigned to the same parts, and illustration and description thereof will be omitted, and only the configurations and operations of different parts will be described.

  In FIG. 6, the imaging light beam 100 reflected upward by the main mirror 40 is incident on the pentaprism 104 via the screen 103 constituting the optical viewfinder 101. The light beam incident on the pentaprism 104 is guided to an imaging surface of a through image CCD (live view CCD) 106 as a second imaging means via an imaging lens 105, and an eyepiece 108, It is guided to the finder window 110 through the eyepiece shutter 109 and visually recognized by the photographer's eyes. An image signal (second image data) generated by being converted into an electrical signal by the through image CCD 106 is output to an analog front end unit (AFE) 44.

  In the present embodiment, the through image mode is selected, and the finder window 110 is covered with an eyepiece shutter 109 provided to prevent back-incident light from the finder window 110. Therefore, in this case, the optical finder cannot be used. Of course, the eyepiece shutter may be opened and the subject may be observed from this optical finder.

  With this configuration, the subject image observed on the screen 103 is always displayed on the liquid crystal monitor 26. At the same time, the focus operation by the AF / AE sensor unit 48 becomes possible. Further, unlike the first embodiment described above, since the light beam incident on the through image CCD 106 is equivalent to the light beam reaching the eyepiece lens 108, a bright image with little noise is displayed on the liquid crystal monitor 26. Is possible. Also, the optical finder can observe the subject brightly as usual.

  As mentioned above, although embodiment of this invention was described, in the range which does not deviate from the summary of this invention other than embodiment mentioned above, this invention can be variously modified.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a first embodiment of the present invention and is an external perspective view illustrating a configuration of a single-lens reflex digital camera. 1 is a block diagram illustrating a schematic system configuration of a camera according to a first embodiment of the present invention. FIG. 3 is a block configuration diagram showing a configuration of an ASIC 55a shown in FIG. 2 and its peripheral part. FIG. 3 is a block configuration diagram showing a configuration of an ASIC 55b shown in FIG. 2 and its peripheral portion. 6 is a flowchart for explaining an operation in a through image mode of the camera in the first embodiment of the present invention. It is a block diagram which shows the schematic system configuration | structure of the camera which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Camera, 5 ... Subject, 10 ... Lens barrel, 12 ... Shooting lens, 13 ... Drive part, 21 ... Release button, 26 ... Liquid crystal monitor, 40 ... Main mirror, 41 ... Prism, 42 ... Eyepiece, 43 ... Through-image CCD, 44, 51 ... Analog front end (AFE), 45, 52 ... CCD block, 47 ... Sub mirror, 48 ... AF / AE sensor unit, 50 ... Main CCD, 55a, 55b ... Application specific integrated circuit (ASIC), 57a, 57b ... flash memory, 59 ... TFT liquid crystal driver, 60 ... TFT block, 62a, 62b ... SDRAM, 63 ... recording medium (Media), 64 ... switch (SW) section, 70a, 70b ... CPU , 82a, 82b... Image processor.

Claims (1)

Photographic optics,
A main mirror that transmits and reflects the subject luminous flux that has passed through the photographing optical system;
An observation optical system for observing an observation image of a screen on which a subject luminous flux reflected from the main mirror is formed, guided to a finder window via a prism;
In a state where the main mirror is retracted from the photographing optical path, the first mirror is based on the subject light flux.
First imaging means for generating the image data of
Provided at any position on the top, bottom, left, and right of the prism off the optical axis of the observation optical system, the main mirror is not retracted from the photographing optical path, and the observation image is guided to the viewfinder window. A second imaging means for generating second image data based on the observation image guided by the prism;
Display means for displaying a subject image based on image data generated by the first imaging means or the second imaging means;
First control means comprising an application specific integrated circuit including a CPU for controlling drive of the first imaging means;
Second control means comprising an application specific integrated circuit including a CPU different from the CPU for controlling the driving of the second imaging means;
A digital camera comprising:

Images