JP2002290800A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera capable of indicating a shutter speed before taking a picture. SOLUTION: When a shutter button is pressed deeper than a 'half press' position at a step S103, a flow goes to step S104 where a proper focus based upon a light signal taken by a CCD, and a shutter speed and an aperture to determine an exposure are determined by a controller. For the shutter speed, for example, one of 1/2, 1/30, 1/125 or 1/750 sec is selected and for the aperture, for example, either F2.5 or F8 is selected and determined. At step 105, the shutter speed determined at S104 is displayed on an LCD putting on an image of a shooting target. At step S106, if the shutter button is perfectly pressed position, a flow goes to step S108 and image data are recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera that converts light from an object to be photographed into digital data and stores the digital data.

[0002]

2. Description of the Related Art Conventionally, there has been known a digital camera which converts light into an electric signal by an optical sensor such as a CCD, converts the electric signal into digital data, and stores the digital data in a storage medium such as a flash memory. In a digital camera, image data can be stored and various processes can be easily performed by an individual using a personal computer or the like, and a photograph can be printed without developing a film by outputting image data to a printer. Further, with the improvement of the printing quality of the printer, it has become possible to print a high-quality photograph that can hardly be distinguished from a silver halide photograph.

[0003] The digital camera as described above has a function of setting an automatic focus (AF) and an automatic exposure (AE) by a control device so that an appropriate photographing can be performed without complicated operations. May be. The exposure is determined by the aperture of the lens and the shutter speed.

[0004]

However, in the conventional digital camera which performs the above-described automatic exposure, after the user presses the shutter button, an appropriate aperture and shutter speed are determined based on information on the detected light amount. You.
Therefore, the user did not know at which shutter speed the image was taken until after the image was taken. At the time of shooting at night or indoors, there is a problem that the shutter speed becomes slow, and shooting failure is likely to occur due to camera shake.

Further, even under almost the same photographing conditions, when the aperture value is switched from a small value to a large value by the automatic exposure setting, the shutter speed is greatly reduced, so that a photographing result unexpected by the user may occur. is there.
SUMMARY An advantage of some aspects of the invention is to provide a digital camera that displays a shutter speed on an image display unit during photographing.

[0006]

According to the digital camera of the first aspect of the present invention, an image pickup unit for converting light from an object to be photographed into image data, and an image display unit capable of displaying an image based on the image data. A control unit that determines an aperture and a shutter speed according to the amount of light from an object to be photographed; and a unit that displays the shutter speed on an image display unit.
Therefore, the user can predict the photographing result to some extent before photographing. Also, when the shutter speed is low, the user can be made aware that the user should be careful about camera shake.

According to the digital camera of the present invention, the control unit can detect the first suppression position and the second suppression position, and the photographing start instruction unit can detect the first suppression position and the second suppression position. When the camera is at the position, the shutter speed determined by the control unit is displayed on the image display unit, and when the shooting start instruction unit is at the second suppression position, shooting is started. Therefore, the shutter speed determined by the control unit is displayed by, for example, so-called “half-pressing” the shutter button, and shooting can be performed at the determined shutter speed by pressing the shutter button “fully”.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is a block diagram for explaining the structure of the digital camera 10 according to one embodiment of the present invention. The digital camera 10 includes a control unit 11, a condenser lens 12, and a charge coupled device (CCD) as an imaging unit.
e) 13, an A / D converter 14, a RAM (Random Access Memory) 15 for temporarily recording image data, a memory card 16 capable of recording compressed image data, and a card slot 20 in which the memory card 16 is removable. , A liquid crystal display (LCD) 21 for displaying images, a VRAM 18 for storing data for images displayed on the LCD 21, an interface 19 for outputting data in the memory card 16 to an external device, and the like. I have.

The control unit 11 includes a CPU and data input / output means, and performs various controls of the digital camera 10 by executing a control program. Condensing lens 12
Is provided with a diaphragm 121 for adjusting the amount of light input to the condenser lens 12. As CCD13, C
(Cyan), M (Magenta), Y (Yellow), G (Green)
By using the CCD 13 in which a plurality of image sensors having complementary color filters are arranged in a matrix, a color image can be taken. Complementary color filters are C,
There may be three colors of M and Y. R (Red), G (Green),
In some cases, a CCD having a primary color filter of B (Blue) is used. As the RAM 15, an SDRAM (Synchronous Dynamic RAM) having a self-refresh function is used.

The memory card 16 has an image recorded in a rewritable storage medium, such as a flash memory, capable of holding recorded contents without power supply, and is detachably mounted in a card slot 20 of the digital camera 10. ing. By using, for example, a memory card conforming to the PCMCIA standard or a memory card attachable to a PCMCIA card adapter as the memory card 16, the contents of the memory card 16 can be directly read and written by a personal computer having a PCMCIA card slot.

FIGS. 3 and 4 show a digital camera 1 according to this embodiment.
0 and 0 are a rear view and a plan view, respectively. Digital camera 1
0 indicates that the user is using the LCD 21 or the optical viewfinder 11
The photographing range is determined by 0, and the photographing is performed by pressing the shutter button 101. The control unit 11 performs “half-pressing” of pressing the shutter button 101 to the middle of the movable range as the first suppression position and “full-pressing” of pressing the shutter button 101 to the limit or near the limit of the movable range as the second suppression position. It can be distinguished and recognized. The user can use the mode switching dial 102 to switch the operation mode of the digital camera to “viewfinder mode”, “LCD”
Mode, OFF, Playback mode, Direct print mode, and Setup mode.

The "viewfinder mode" is a mode in which photographing is mainly performed using an optical viewfinder in order to save power consumption of the digital camera 10. "LCD
The “mode” is a mode in which shooting is mainly performed using the LCD as a finder. The “playback mode” is a mode for displaying an image based on image data that has already been captured and recorded on the memory card 16. The “direct print mode” is a mode for connecting the digital camera 10 to an external printer via an interface and printing an image. The “setup mode” is a mode for performing various settings such as photographing conditions of the digital camera 10. Mode switch dial 102 is "OFF"
When set to the position, the power of the gauge camera 10 is turned off.

Input keys 103 to 103 are provided around the LCD 21.
109 are provided. The control unit 11 executes a control program according to the selected mode. Then, the user presses the shutter button 101 or the input keys 103-1.
09 is detected, and a corresponding operation is performed.

An image quality selection button 111, a strobe selection button 112, and a mode selection button 113 are provided above the digital camera 10. When the image quality selection button 111 is pressed, the recording image quality is changed by changing the compression ratio and the number of pixels of the image data. When the strobe selection button 112 is pressed, the strobe light emission mode can be selected from automatic light emission, constant light emission, and no light emission. When the mode selection button 113 is pressed, switching between a normal shooting mode, a close-up shooting mode, an enlarged shooting mode, a panorama shooting mode, and the like can be performed. Each selection button 111, 112,
The content set by 113 is a segment type LCD
It is displayed at 114.

Next, the operation of the digital camera 10 of this embodiment when an image is taken will be described. When the mode switch dial 102 is set to the position "SH1," the viewfinder mode is set. In the viewfinder mode, the LCD 21 is not energized and the LCD 2
1 is a non-display state. Normally, the power is not supplied to the CCD 13, and the operation of the CCD 13 starts when the user half-presses the shutter button 101, and the control unit 1 operates based on information on light from the imaging target detected by the CCD 13.
The setting of the exposure, the setting of the focus, the setting of the white balance, and the like are automatically performed by 1. The exposure is determined by the shutter speed and the aperture 121 of the lens 12. The user uses the optical viewfinder 110 to determine a shooting range.

When the user fully presses the shutter button 101, photographing is started, and image data is created according to the following process. First, all the charges accumulated in the CCD 13 are once discharged, and then the light collected by the condenser lens 12 is input to the CCD 13. CCD13
Is the shutter speed in the digital camera 10. In the CCD 13, the light is converted into electric charges according to the amount of light. The electric signal output from the CCD 13 is converted into a digital signal by the A / D converter 14. The digital data output from the A / D converter 14 is transferred by direct addressing of the RAM 15 without directing the control unit 11 by DMA (Direct Memory Access) for speeding up.

Since the data transferred from the CCD 13 has only information corresponding to one color per pixel, the RAM 1
The color interpolation is performed on the data recorded in No. 5 based on the color information of surrounding pixels to create image data having color information for each pixel of, for example, 1280 × 960 pixels.

Next, in order to increase the number of recorded images on the memory card 16, JPEG (Joint Photographic Experts G
The data is compressed by a lossy compression method based on the standard (roup) to generate compressed data having a small capacity. JPEG is a commonly used color image compression method, and the storage image quality can be adjusted by changing the compression ratio. JPEG
The compression may be performed by the control unit 11 using software, or a dedicated circuit may be used to increase the speed.
The JPEG-compressed compressed data is recorded on the memory card 16.

When the mode switching dial 102 is set to "SG
When set to the position "2", the LCD mode is set. Digital camera 1 when shooting in LCD mode
FIG. 1 is a flowchart illustrating the control performed by the control unit 0.
In step S101, the control unit 11 causes the CCD 13
Is converted into a digital signal and read. In step S102, a shooting target is displayed on the LCD 21 based on the digital signal read in step S101.

In step S103, the control unit 11 detects the suppression position of the shutter button 103, and when the shutter button 101 is pressed more than "half-press",
The process proceeds to S104, and if not pressed, returns to S101. By displaying the image of the shooting target on the LCD 21 every several seconds to several tenths of a second, the shooting target is displayed as a moving image.

In step S104, the controller 11 determines an appropriate focus, a shutter speed and an aperture for determining exposure based on the information obtained from the CCD 13. The shutter speed is, for example, 1/2 second, 1
Any of / 30 seconds, 1/125 seconds or 1/750 seconds is selected, and the aperture is determined by selecting, for example, one of F2.4 and F8. In step S105,
As shown in FIG. 3, the shutter speed determined in S104 is displayed on the LCD 21 so as to be superimposed on the image to be captured.

In step S106, the control unit 11 detects the suppression position of the shutter button 103, and if the shutter button 101 is fully pressed, the process proceeds to step S108. If the shutter button has not been fully pressed, it is determined in step S107 whether or not the shutter has been half-pressed. If the shutter button has been half-pressed, the flow returns to S106;

In step S108, shooting is started with the aperture and shutter speed determined in step S104.
Image data is created in the same procedure as in the viewfinder mode, and the JPEG-compressed compressed data is recorded on the memory card 16. Image data is memory card 1
Although it may take several seconds to several tens of seconds from the start of recording to the completion of recording on the LCD 6, an image based on the image data is continuously displayed on the LCD 21 during that time.

According to the digital camera of this embodiment, LC
When shooting in D mode, the shutter button 101
When the shutter button is pressed halfway, the shutter speed at which shooting is performed is displayed on the LCD 21, so that shooting is not performed at a shutter speed unexpected by the user. Also, when the shutter speed is low, the user can be made aware that the user should be careful about camera shake.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flowchart of a photographing process by a digital camera according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a digital camera according to an embodiment of the present invention.

FIG. 3 is a plan view showing a digital camera according to one embodiment of the present invention.

FIG. 4 is a rear view showing the digital camera according to one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 digital camera 11 control unit 12 condenser lens 121 aperture 13 CCD (imaging unit) 14 A / D converter 15 RAM 16 memory card 17 built-in flash memory 18 VRAM 19 interface 20 card slot 21 liquid crystal display device (LCD, image display unit) ) 101 Shutter button (photographing start instruction means)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/238 H04N 5/238 Z 5/907 5/907 B // H04N 101: 00 101: 00 F term (Reference) 2H054 AA01 2H102 AA02 BB01 5C022 AA13 AB02 AB15 AB55 AC03 AC13 AC32 AC52 5C052 AA17 DD02 EE08 FA02 FA03 FA06 FE01 GA02 GA05 GA09 GB06 GB09 GE08

Claims (2)

[Claims] An imaging unit configured to convert light from an imaging target into image data; an image display unit capable of displaying an image based on the image data; and an aperture and a shutter speed determined according to a light amount from the imaging target. A digital camera, comprising: a control unit that performs the operation; and a unit that displays the shutter speed on the image display unit. 2. The control device according to claim 1, wherein the control unit includes a first suppression position and a second suppression position.
A photographing start instructing means capable of detecting the suppression position of: a means for displaying the shutter speed determined by the control unit on the image display unit when the photographing start instructing means is at the first suppression position; 2. The digital camera according to claim 1, further comprising: a unit that starts photographing when the photographing start instruction unit is at the second suppression position. 3.