KR20110088880A - Digital photographing apparatus, and control method thereof - Google Patents

Abstract

The present invention provides an image sensor comprising a pixel array in which a plurality of pixels are arranged in rows and columns. The pixel array includes an effective area in which an image of a subject is converted into an electrical signal, and an invalid area located outside the effective area. And a shutter for controlling the exposure amount to the image sensor, an optical measuring unit disposed in the ineffective area and measuring the exposure amount, and a comparison of judging whether or not the exposure amount measured by the optical measuring unit corresponds to a reference exposure amount. And a shutter control unit for adjusting the operation of the shutter according to the reference exposure amount if it does not correspond to the determination result.

Description

Digital photographing apparatus, and a method for controlling the same

The present invention relates to a digital photographing apparatus, and more particularly, to provide a digital photographing apparatus capable of adjusting a shutter operation in an image sensor itself, and a control method thereof.

A general camera is provided with a focal plane shutter as a shutter mechanism for adjusting the amount of light of a subject introduced through a lens group. In the focal plane shutter, two thick curtains and a curtain curtain that block the screen of the image sensor simultaneously operate with the shutter button, thereby exerting a shutter function. In the focal plane shutter, the front curtain shades the screen of the image sensor and the rear curtain waits on the image sensor while the recording operation is started. The image data of one screen is acquired while the image of the subject is read through the slit-shaped opening moving from the top to the bottom of the image sensor (the operation of the focal plane shutter will be described later with reference to FIG. 2).

Such focal plane shutters perform slit exposure at high speeds. At this time, it is ideal that the first, middle, and final times all coincide, but for this, the driving curve must match and the speed of the membrane must match. The running curve is determined by the characteristics of the driving spring, the mechanism of the membrane, the mass, the friction, and the like, so that only the speed of the membrane can be adjusted after the design. For example, assuming that the shutter time is 0.12 msec, the exposure time at the top of the image sensor is 0.12 msec even if the rear curtain is only 0.1 msec later than the front curtain, but the exposure time at the bottom is 0.22 msec, so that the exposure time at the top and bottom is approximately 2 times difference. Such exposure unevenness occurs when the exposure time of the three points is incorrect. Although it can be made small by adjusting the driving spring, it is not zero because the deviation of the start position of the film is necessarily present. This mecha structure brings with it a limit of faster shutter speeds with stains.

In order to solve this problem, the adjustment process between the thick film and the front curtain is essential. In particular, since the upper end and the lower end of the subject are not imaged in the exact same time zone, there is a problem that exposure spots occur. In addition, the sensor shutter adjustment should theoretically be performed by measuring three data points at the top and bottom, but since it is impossible to adjust all three points, it is common to acquire only the data at the center of the shutter and use them as adjustment data. In order to solve such a problem, a shutter having a photo interrupter disposed on the shutter tester and the shutter unit itself has been developed.

However, there was a problem that the shutter tester was expensive and the camera could not be adjusted by itself, and in the case of the shutter having the photo interrupter disposed on the shutter unit itself, the structure of the installation became complicated and additional processes were required, resulting in an increase in the camera cost. . In addition, the width of the shutter is inevitably increased, which is not suitable for the recent trend toward making the DSLR small and light.

An object of the present invention is to provide a digital photographing apparatus that can adjust the operation of the shutter in the image sensor itself, and a control method thereof.

In order to solve the above problems, according to an aspect of the present invention, an image sensor consisting of a pixel array in which a plurality of pixels are arranged in rows and columns (the pixel array is an effective area in which the optical image of the subject is converted into an electrical signal, And an ineffective area positioned outside the effective area; a shutter for controlling an exposure amount of the image sensor; an optical measuring unit disposed in the ineffective area and measuring an exposure amount of the image sensor; And a comparison judging unit which compares and determines whether the exposure dose measured in Fig. 2 corresponds to the reference exposure amount, and a shutter control unit which adjusts the operation of the shutter according to the reference exposure amount if the comparison determination result does not correspond. To provide.

According to another aspect of the present invention, the optical measuring unit may include an optical sensor disposed on a row line on the center extension line of the effective area among each row line in the invalid area.

According to still another aspect of the present invention, the optical measuring unit includes a plurality of optical sensors which are arranged for each row line in the ineffective area and measure the exposure amount of the image sensor for each row line, respectively. The comparison determination unit compares and determines whether each exposure amount measured by the plurality of optical sensors corresponds to a reference exposure amount, and the shutter control unit may adjust the operation of the shutter according to the reference exposure amount if the comparison determination result does not correspond. .

According to another feature of the present invention, the reference exposure amount may be an exposure amount measured from an optical sensor disposed on a row line on a center extension line of the effective area among each row line in the ineffective area.

According to another feature of the invention, the optical measuring unit is further configured to measure an exposure start time, the digital camera comprising: a flash emitting unit; A flash controller for controlling light emission of the flash light emitter; And a synchronizer configured to synchronize the light emission start time and the light emission amount of the flash light emission unit with the exposure start time and the exposure amount measured by the light measuring unit, wherein the flash control unit is adapted to the synchronized light emission start time and the light emission amount. It is characterized by controlling the light emission of the flash light emitting portion.

According to still another feature of the present invention, the shutter may be a focal plane shutter having a front curtain as a film body for optical path opening operation and a thick film as a film body for optical path blocking operation.

According to another feature of the invention, the operation of the shutter includes at least the optical path opening operation and the optical path blocking operation, wherein the shutter control unit to control the exposure amount by using the moving speed difference between the front curtain and the thick film You can adjust the speed.

In order to solve the above technical problem, another aspect of the present invention provides a method for controlling the digital photographing apparatus as described above.

Conventionally, if the time due to the movement of the front curtain and the thick film on the basis of the mechanical shutter is measured, the present invention can be said to be more accurate by measuring the exposure amount on the sensor surface reference. The shutter can be adjusted by the image sensor itself, so that it can be adjusted only in a specific place, such as an AS point equipped with a specific device, in a general environment. In particular, an expensive shutter tester is not needed (approximately 2 ~ 30 million won per unit), and the adjustment process is reduced by one step, thereby increasing productivity. Compared with the method of employing a photointerrupter in the shutter itself as a recent technology, the structure of the shutter is simple and the cost can be made cheap. Normally, 100,000 to 300,000 shutter lifespans are extended permanently.

In addition, since the exposure start time can be known from the photosensor, the exposure start time and the exposure amount are determined according to this time, so that the same flash emission amount can be achieved for each line even in a high speed shutter.

1 is a side cross-sectional view schematically showing the configuration of a digital photographing apparatus according to an embodiment of the present invention.
2 is a schematic block diagram of a digital photographing apparatus according to an embodiment of the present invention.
3 is a block diagram schematically illustrating a configuration of a CPU according to an embodiment of the present invention.
4 is a diagram schematically illustrating an operation of the focal plane shutter 121.
5 is a diagram illustrating the image sensor 131.
6 is a diagram schematically illustrating an image sensor 131 having a light measuring unit 250 according to an embodiment of the present invention.
FIG. 7 is a flowchart illustrating a method of adjusting a shutter operation by using the image sensor 131 having the optical measuring unit 250 of FIG. 6.
8 is a diagram illustrating an image sensor 131 incorporating an optical measuring unit 250 according to another exemplary embodiment.
FIG. 9 shows an example in which the flash is used in the slit exposure by emitting a plurality of short luminescences called HSSs several times in a prior art.
FIG. 10 is a view illustrating an existing method for maintaining a constant flash emission amount for each line of an image sensor and a shutter (upper film 121a and thick film 121b) of upper and lower vertical pillars in a method according to another embodiment of the present invention. In the drawing, the slit exposure and flash emission are shown in the x-axis and the y-axis in terms of the amount of light.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the present specification and drawings, redundant description is omitted by attaching the same reference numerals to the components having substantially the same functional configuration. In addition, the following description and the accompanying drawings are for understanding the operation according to the present invention, the part which can be easily implemented by those skilled in the art can be omitted.

In addition, the specification and drawings are not provided to limit the invention, the scope of the invention should be defined by the claims. Terms used in the present specification should be interpreted as meanings and concepts corresponding to the technical spirit of the present invention so as to best express the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a side cross-sectional view schematically showing the configuration of a digital photographing apparatus according to an embodiment of the present invention, Figure 2 is a schematic block diagram of a digital photographing apparatus according to an embodiment of the present invention.

The digital photographing apparatus according to the present embodiment illustrated in the drawings is a single lens reflex (SLR) camera and is a digital camera that can be attached and detached from a lens unit. However, the digital photographing apparatus shown in the drawing is merely an example to facilitate the description of the present invention, and the present invention is not limited to the configuration shown in the drawing.

Referring to the drawings, in the digital photographing apparatus 100 according to the present embodiment, the light reflected from the subject is transmitted to the image sensor unit 130 through the lens unit 110 and the shutter unit 120.

The lens unit 110 includes a lens 111, an aperture 113, a reflector 115, a pentaprism 116, and the like.

The digital photographing apparatus 100 according to the present exemplary embodiment is a single-lens reflex camera, and when the mirror 115 is down, the light entering through the lens 111 is reflected by the reflector 115. The light measuring unit 250 is reached through a pentaprism 116.

On the other hand, when the reflector 115 of the single-lens reflex camera is up and the shutter 121 is open, the light entering through the lens 111 is received by the image sensor 131 to display 3 of the subject. An image is formed into a 2D image corresponding to the 3D image.

The image sensor 131 includes an optical measuring unit 250 disposed in the image sensor 131. The optical measuring unit 250 measures the exposure amount to the image sensor using a photoconductive light emitting device or a light receiving device. The optical measuring unit 33 may include, for example, a photointerrruptor and an optical sensor, but is not limited thereto. The photointerrupter is a device which is capable of detecting an object, detecting a position, counting, etc. by blocking an optical path with one of the photocouplers. The optical sensor is a device for detecting an object, detecting a position, counting, etc. by blocking an optical path with one of the photocouplers. The optical sensor is simpler than a photo interrupt and can be implemented in a general configuration.

Although the lens 111 is not shown in detail in the drawing, the zoom lens moves back and forth in the optical axis direction and continuously changes the focal length, the focus lens for adjusting the focus of the image of the subject formed in the image sensor 131, and And a compensation lens.

The position of the lens 111 of the lens unit 110 is controlled by the lens driving unit 112, the aperture 113 is controlled by the aperture driving unit 114, and the like, and the reflector 115 is released. It is driven by the reflector driver 117 by receiving a signal. These drivers 112, 114, and 117 receive a control signal from the CPU 240.

The shutter unit 120 includes a shutter 121 and a shutter driver 122.

The shutter 121 controls the exposure time (or exposure amount) to the image sensor 131 at the time of shooting. The shutter 121 in this embodiment is a focal plane shutter disposed parallel to the front of the image pickup surface of the image sensor 131 and is configured to be openable and closed to shield or open the light irradiated onto the image pickup surface.

Light incident through the lens unit 110 and the shutter 120, that is, the optical signal, is converted into an electrical signal by the image sensor unit 130. In detail, the image sensor unit 130 drives the image sensor 131 and the image sensor 131 such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) that converts an optical signal into an electrical signal. And an image sensor driver 132.

Although not shown in the drawing, a timing controller (not shown) for controlling the exposure period or reading control of the charge of each pixel constituting the image sensor 131 may be further provided.

The A / D converter 140 converts the analog electrical signal generated by the image sensor 131 into a digital signal, and the converted digital image signal becomes original (RAW) data.

The image signal processor 150 is a signal processing unit capable of displaying digitally converted RAW data of an analog image. The image signal processor 150 removes a black level caused by dark current generated by CCD and CFA filters sensitive to temperature change. In addition, gamma correction for encoding information according to non-linearity of human vision, CFA interpolation for interpolating Bayer pattern implemented with RGRG line and GBGB line of predetermined gamma-corrected data to RGB line, and converting interpolated RGB signal to YUV signal Edge compensation for processing the image clearly by filtering the Y signal by a high band filter, and image processing such as correcting color values of the U and V signals and removing noise using a standard color coordinate system are performed.

The video signal generated as described above is temporarily stored in the buffer memory 160, and the temporarily stored video signal is displayed on the display unit 175 under the control of the display controller 170.

In the present embodiment, the display unit 175 is formed of a liquid crystal display (LCD), but the display unit 175 according to the present invention is an organic light-emitting diode, a field emission display: FED) or the like.

In addition, before the photographing instruction signal is input, the light passing through the lens unit 110 is transmitted to the image sensor 131 while the reflecting mirror 115 is lowered and the photographing standby state in which the shutter 121 is opened continues. The screen of the image-formed subject processed is displayed in the live view through the display unit 175.

On the other hand, the video signal temporarily stored in the buffer memory 160 may be input to the recording / reading control unit 180, the recording / reading control unit 180 is a smart card, compact flash (automatically) according to the signal from the user or automatically The recording medium 185 may be recorded in various types of recording media 185 such as a compact flash (CF) memory, a memory stick, and a secure digital (SD) memory card. Of course, the recording / reading control unit 180 reads the image data from the image file stored in the recording medium 185 and inputs it to the display control unit 170 through the buffer memory 160 so that the image is displayed on the display unit 175. You may.

The power supply unit 190 supplies a predetermined power for the digital photographing apparatus 100 to operate, and may include an interface connected to a battery such as a built-in lithium ion battery and / or an external power supply.

The storage unit 200 is an EEPROM (Electrically Erasable and Programmable Read Only Memory) storing algorithms for various operations of the digital photographing apparatus 100 and a flash storing setting data necessary for operation of a processor of the digital photographing apparatus 100. The memory may further include a flash memory.

The manipulation unit 210 includes buttons for allowing a user to perform an operation of the photographing apparatus or to perform various settings when photographing. For example, it includes a power button, a first shutter release button S1 as a half shutter, a second shutter release button S2 as an on shutter, a function button for selecting a shooting mode or a reproduction mode, and setting effect parameters. On the other hand, the operation unit 210 is not limited to the above buttons, etc., it may have various forms such as a touch screen, a touch pad, a remote controller.

The photometric sensor 220 calculates an appropriate exposure amount to the subject by measuring the amount of light reflected from the subject using a photoconductive light receiving element. In particular, the photometric sensor 220 according to the present invention includes a subject. A TTL (through the lens) metering method is used to measure the exposure time by the light passing through the lens unit 110.

The flash controller 230 controls the light emission of the flash light emitter 235, and in particular, controls the light emission operation linked to the simultaneous reset of the image sensor 131 or the opening / closing operation of the shutter 121.

The flash emitter 235 is applied to emit light at the time of shooting in order to brighten the subject when shooting at night or in a dark place, or to effectively shoot even in a bright place.

Light emission control of the flash light emitter 235 is performed by the flash controller 230 receiving a signal from the CPU 240 and outputting a light emission command to the flash light emitter 235. The flash light emitting unit 235 performs preliminary light emission before the main exposure and the main emission during the main exposure, and may be provided in the digital photographing apparatus 100 in a form that can be embedded and / or externally.

The digital photographing apparatus 100 includes a CPU 240 for controlling the overall operation. The CPU 240 outputs a predetermined control signal to the lens driver 112, the aperture driver 114, and the reflector driver 117 to control the respective components according to the exposure information, the focus information, the external input signal, and the like. have. In addition, the present embodiment includes only one CPU 240, but is not necessarily limited thereto, and may include a plurality of CPUs 240. In this case, the command of the signal system and the command of the operation system may be executed. ) Can be done.

3 is a block diagram schematically illustrating a configuration of the CPU 240 according to an embodiment of the present invention.

Referring to FIG. 3, the CPU 240 compares and determines whether the exposure amount measured by the optical measuring unit 250 corresponds to the reference exposure amount, and when the comparison decision result does not correspond, the reference exposure amount. The shutter control unit 242 for adjusting the operation of the shutter according to the. The operation of the shutter controller 242 will be described later with reference to FIG. 7. The CPU 240 may further include a synchronizer 243 for synchronizing the exposure start time and the exposure amount detected by the light measuring unit 250 with the emission start time and the emission amount of the flash.

4 is a diagram schematically illustrating an operation of the focal plane shutter 121.

Referring to FIG. 4, in the shutter 121, two or four thin films 121a and 121b are disposed on the front and rear of the shutter to shield the screen of the image sensor 131. The set lever 400 connected to each membrane is controlled while being attached to and detached from the magnets 410a and 410b.

In the shooting standby state, the front curtain 121a shields the screen to shield the image sensor 131 and the thick film 121b is folded upward.

When shooting starts, the set lever 400 goes up with the mirror up and the rear curtain magnets 410a and 410b are turned on to fix the rear curtain.

Exposure is started when the curtain magnet 410a is turned off. When the thick film magnet 410b is turned off, the photographing is completed. After the mirror 115 is down, the process returns to the shooting standby state.

5 is a diagram illustrating the image sensor 131.

Referring to FIG. 5, the image sensor 131 has a pixel array structure in which a plurality of pixels are arranged in rows and columns, and includes the pixel array effective area 500 (part of a dotted line) and the effective area 500. The non-effective area 510 (part outside the dashed line) located outside is divided.

The effective area 500 is an area including active pixels, and the effective pixels in the effective area 500 are pixels that are actually used to convert an optical image of a subject into an electrical signal. On the other hand, the invalid area is an area including optical black (OB) pixels and dummy pixels, and the optical black (OB) pixels and dummy pixels in the invalid area are used to convert an optical image of a subject into an electrical signal. These are pixels that aren't actually used.

6 is a diagram schematically illustrating an image sensor 131 having a light measuring unit 250 according to an embodiment of the present invention.

Referring to FIGS. 6A and 6B, the optical measuring unit 250 measuring the exposure amount (or exposure time) to the image sensor 131 may be configured as an ineffective area 510 (the image sensor 131). OB or dummy pixels region). In particular, the photodetector 250 is an optical sensor 250a positioned in an invalid area 510 (OB or dummy area) corresponding to the center position 600a with respect to the effective area 500 of the image sensor 131. Including, the exposure time of the center of the image sensor 131 can be measured. (The data in the OB area does not use the entire area when taking images). Position and number of the optical sensor is only an embodiment according to the present invention, but is not limited thereto.

FIG. 6 (b) is a more detailed view of the image sensor 131 incorporating the optical measuring unit 250.

Referring to FIG. 6B, in the image sensor 131, a plurality of pixels are arranged on a plurality of pixel lines (matrix-shaped arrangement). In the case of columns 1,2 (OB pixels) and columns 3 to n (Active pixels), the center extension line of the image sensor 131 (that is, the effective area 500) among the invalid areas 510 (OB areas). Alternatively, means for attaching an optical sensor 250a to a pixel located on the center row line 600a to measure an exposure amount (or exposure time) is provided.

As the number of use of the shutter increases, the exposure of the focal plane shutter may change, and eventually, the slit-type opening time by the front curtain and the thick curtain may be eliminated in the high speed shutter. Therefore, the camera obtains the mechanical shutter exposure time information from the optical sensor 250a included in the image sensor 131 every time the image is taken to determine the need for adjusting the shutter exposure amount, and performs the exposure amount inspection or adjustment process if necessary.

FIG. 7 is a flowchart illustrating a method of adjusting a shutter operation by using the image sensor 131 having the optical measuring unit 250 of FIG. 6.

A method of adjusting a shutter operation in the digital photographing apparatus 100 according to an exemplary embodiment will be described with reference to FIG. 7.

In the focal plane shutter 121, the front curtain 121a shields the screen of the image sensor 131 while the rear curtain 121b is waiting on the photographing standby state (S700).

When the photographing operation is started, the rear film 121b moves along the front curtain 121a with the slit-shaped opening exposed by the movement of the front curtain 121a, and the slit type proceeding from the top to the bottom of the image sensor 131. The exposure amount of the exposure to the image sensor 131 through the opening is measured by the optical measuring unit 250 built in the ineffective area 510 (S710).

It is determined whether the measured exposure amount corresponds to the reference exposure amount (S720). At this time, the performance of the focal plane shutter 121 is inspected using the non-effective area 510 of the image sensor 131, the data of the image sensor 131 is calculated by the CPU 240, and the adjustment data is calculated by the CPU 240. Can be applied on its own. In addition, if the difference between the measured exposure amount and the reference exposure amount is within a preset error standard (eg, when the shutter speed is 1/4000 = 0.244 ms, the error standard is set to 0.244 ± 0.02 ms), it can be regarded as corresponding.

If it does not correspond, that is, out of the preset error specification range, the operation of the shutter is adjusted according to the reference exposure amount (S730). At this time, the step (S630) of controlling the operation of the shutter informs the user of the necessity of the shutter adjustment when it is out of the error specification range, performs the shutter inspection, calculates the adjustment value after the inspection, and automatically applies and changes the adjustment value. It may include notifying the user of the test result after the retake and ending the shutter adjustment.

The operation of the shutter includes at least the optical path opening operation and the optical path blocking operation, and therefore the shutter controller 242 can adjust the speed of the shutter to control the exposure amount by using the moving speed difference between the front curtain and the rear curtain of the shutter. In addition, the shutter controller 242 may calculate and adjust a shutter speed, an F number, a flash emission amount, and the like necessary for exposure.

When the adjustment of the shutter is finished, the process returns to the shooting standby state (S740).

8 is a diagram illustrating an image sensor 131 incorporating an optical measuring unit 250 according to another exemplary embodiment.

The optical measuring unit 250 may include a plurality of optical sensors that are disposed for each row line in the ineffective area and measure the exposure amount of the image sensor 131 for each row line.

That is, an optical sensor capable of measuring the exposure of the image sensor 131 is provided for each side so as to obtain actual exposure information of each line, and at the exposure value of the image sensor 131, the center row line [i.e. [I.e., the exposure amount of the optical sensor 250a is set as the reference exposure amount] on the basis of the exposure amount of the optical sensor 250a on the center pixel of the center extension line 600a with respect to the effective area 500, and the upper low line ( The exposure amount is corrected as the exposure amount of the light sensor 250b on the upper pixel of the 600b is less than that of the light sensor 250a, and the exposure amount of the light sensor 250c on the lower pixel of the lower row line 600c is subtracted. You can control the exact amount of exposure to the pixels. Position and number of the optical sensor is only an embodiment according to the present invention, but is not limited thereto.

For example, when the shutter speed is 1/4000 (0.244 ms) and the upper optical sensor 600b measures 0.208 ° center portion 0.239 and the lower part 0.321, the image processing is performed based on the exposure time of the mechanical shutter of the optical sensor. The exposure dose is corrected as follows, and the exposure amount of 0.239-0.208 = 0.031 ms is added to the upper cell, and the exposure amount of 0.321-0.239 = 0.082 ms is subtracted from the lower cell. Every pixel has an even exposure so you can get an accurate image.

Therefore, in the high-speed shutter, the exposure time of the upper and lower portions of the image sensor 131 is different, and as the life span expires, the gap between the following slits becomes narrower and the slits eventually disappear. Through the image sensor 131 in which the optical measuring unit 250 of 7 is embedded, the exposure time of the upper and lower portions of the image sensor 131 can be adjusted.

On the other hand, the optical measuring unit 250 of the present invention can be expected to improve the HSS (High speed SYNC.) In the flash synchro technology. Since the flash emission time varies depending on the time axis, when the flash is emitted by a high-speed shutter that performs slit exposure, it is impossible to uniformly expose the upper and lower pixels.

FIG. 9 is an example in which a short flash called an HSS is emitted several times in a row in order to compensate for this, so that the flash can be used even in a slit exposure. However, since the high speed shutter is not synchronized with the HSS, the same amount of flash light emission cannot be applied to the subject.

FIG. 10 is a view illustrating a slit exposure and a flash emission in x-axis time as light amount in a conventional method for maintaining a constant flash emission amount for each line of an image sensor and a method according to another embodiment of the present invention. In addition, the upper and lower shutters (front curtain 121a and thick film 121b) are shown from left to right.

FIG. 10A illustrates a result of applying the conventional method, and FIG. 10B illustrates an image sensor 131 having an optical measuring unit 250 embedded in an invalid area 510 of the image sensor 131, according to another exemplary embodiment. Is the result of applying.

Referring to FIG. 10A, in the conventional method for making the flash output amount constant for each line of the image sensor, since the light emission time of the flash emitter is different depending on the time axis, when the flash is emitted by a high-speed shutter having a slit exposure, Since it is impossible to uniformly expose all of the pixels, in order to compensate for this, a short emission called HSS is emitted several times in succession so that the flash can be used even in the slit exposure. However, since the high speed shutter is not synchronized with the HSS, the same amount of flash light emission cannot be applied to the subject. Since the light emission of the flash emitter and the movement of the focal train shutter are not synchronized with each other, it is difficult to apply the same amount of flash light of each line of the image sensor. Therefore, the conventional method is to perform a flash emission of a shorter period than the shutter slit to reduce this error. However, many control components and price increases are necessary to incorporate the HSS function of Flash. Therefore, it is common to mount an external flash and not to use the internal flash of the body due to control and cost.

Referring to FIG. 10B, since the exposure start time can be known from the optical measuring unit 250, the exposure start time and the exposure amount are determined according to this time. The amount of light emitted can be achieved.

Referring again to FIG. 2, the digital photographing apparatus 100 includes an exposure start time measured by the flash light emitter 225, the flash controller 230 that controls the light emission of the flash light emitter, and the photometer 250. And a synchronization unit 243 for synchronizing the light emission start time and the light emission amount of the flash light emission unit 225 with the overexposure amount, and the flash controller 230 controls the flash light emission unit 225 according to the synchronized light emission start time and the light emission amount. Light emission can be controlled.

Therefore, according to the present invention, by synchronizing the flash shutter with the mechanical shutter, the number of flashes is reduced, so that the control is easy, and the built-in flash can be implemented.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true scope of protection of the present invention should be defined by the technical spirit of the appended claims.

100: digital photographing apparatus 110: the photographing unit
111: lens 112: lens driving unit
113: aperture 114: aperture driving unit
115: reflector 116: pentaprism
117: reflector drive unit 120: shutter unit
121: shutter 122: shutter driver
130: image sensor unit 131: image sensor
132: image sensor driver 140: A / D conversion unit
150: image signal processor 160: buffer memory
170: display control unit 175: display unit
180: recording / reading control unit 185: recording medium
190: power supply unit 200: storage unit
210: operation unit 220: photometric sensor
230: flash control unit 235: flash light emitting unit
240: CPU 250: optical measuring unit

Claims (7)

An image sensor comprising a pixel array in which a plurality of pixels are arranged in rows and columns, wherein the pixel array is divided into an effective area in which an image of a subject is converted into an electrical signal, and an invalid area located outside the effective area;
A shutter for controlling the exposure amount to the image sensor;
An optical measuring unit disposed in the ineffective area and measuring an exposure amount;
A comparison determination unit for comparing and determining whether the exposure amount measured by the optical measuring unit corresponds to a reference exposure amount; And
And a shutter control unit for adjusting the shutter operation according to the reference exposure amount if it does not correspond as a result of the comparison determination. The method of claim 1,
And the optical measuring unit comprises an optical sensor arranged at a row line on a center extension line of the effective area among the row lines in the invalid area. The method of claim 1,
The optical measuring unit includes a plurality of optical sensors disposed at each row line in the non-effective area and measuring exposure amounts of the image sensor for each row line, respectively.
The comparison determination unit compares and determines whether each exposure amount measured from the plurality of optical sensors corresponds to a reference exposure amount,
And the shutter control unit adjusts the shutter operation according to the reference exposure amount if it does not correspond as a result of the comparison determination. The method of claim 3,
And the reference exposure amount is an exposure amount measured from an optical sensor arranged at a row line on a center extension line of the effective area, among the row lines in the ineffective area. The method of claim 1,
The optical measuring unit is further configured to measure an exposure start time,
The digital camera is:
Flash light emitting unit;
A flash controller for controlling light emission of the flash light emitter; And
And a synchronizer for synchronizing the light emission start time and the light emission amount with the exposure start time and the exposure amount measured by the optical measuring unit.
And the flash controller controls light emission of a flash light emitter according to the synchronized light emission start time and light emission amount. The method according to any one of claims 1 to 5,
And the shutter is a focal plane shutter having a front curtain as a film body for optical path opening operation and a thick film as a film body for optical path blocking operation. The method of claim 6,
The operation of the shutter includes at least the optical path opening operation and the optical path blocking operation,
And the shutter control unit adjusts a shutter speed to control an exposure amount by using a shift speed difference between the front curtain and the rear curtain.

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