(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2006/0165399 A1
`Feng et al.
`(43) Pub. Date:
`Jul. 27, 2006
`
`US 2006O165399A1
`
`(54) METHOD FOR AUTOMATICALLY
`COORONATING FLASH INTENSITY AND
`CAMERA SYSTEMAS THE SAME
`(75) Inventors: Wang Chang Feng, Hang-Zhou (CN);
`Du Wei Jia, Hang-Zhou (CN)
`Correspondence Address:
`TROXELL LAW OFFICE PLLC
`SUTE 1404
`S2O5 LEESBURG PIKE
`FALLS CHURCH, VA 22041 (US)
`(73) Assignee: Asia Optical Co., Inc.
`
`(21) Appl. No.:
`(22) Filed:
`
`11/158,057
`Jun. 22, 2005
`
`(30)
`
`Foreign Application Priority Data
`
`Jan. 26, 2005 (TW)........................
`
`- - - - - - - - - - - - - - - - O941 O2353
`
`Publication Classification
`
`(51) Int. Cl.
`GO3B 5/02
`
`(2006.01)
`
`
`
`
`
`(52) U.S. Cl. ................................................................ 396/61
`
`(57)
`
`ABSTRACT
`
`A camera system with function of automatically coordinat
`ing flash intensity includes a lens, an image sensor, a focus
`system, a focus sensor and a control unit. The lens is capable
`of controlling light amount that entrance into camera. The
`focusing system is capable of driving the lens to focus
`thereby forming a clear image on the image sensor. The
`focus sensor is capable of sensing first step information of
`the focusing system during the focusing process, and send
`ing the information to a control unit. The control unit is
`capable of transforming the result of the focusing system to
`a distance that the object apart from the camera, and
`configures out the guide number with the aperture number
`thereby calculating the flash intensity. The present camera
`systems without neither a professional measurement tool nor
`an additional pre-flash may measure the distance that the
`objects apart from the camera, and low down the cost and
`power consumption. The camera systems may also precisely
`control the flash intensity thereby coordinating the exposure
`effect.
`
`Focusing with a
`focus motor
`
`
`
`
`
`
`
`
`
`Calculating steps that the
`focus motor has worked, and
`looking through a pre-stored
`table for a distance that the
`object aparts from the camera.
`
`Calculating a result to
`coordinate the flash
`intensity with the distance
`and the present focal length
`
`
`
`Qualcomm, Exh. 2006, p. 1
`Apple v. Qualcomm, 2018-01277
`
`

`

`Patent Application Publication Jul. 27, 2006 Sheet 1 of 3
`
`US 2006/0165399 A1
`
`
`
`
`
`
`
`
`
`
`
`Focusing with a
`focus motor
`
`
`
`Calculating steps that the
`focus motor has worked, and
`looking through a pre-stored
`table for a distance that the
`object aparts from the camera.
`
`Calculating a result to
`coordinate the flash
`intensity with the distance
`and the present focal length
`
`FIG 1
`
`Qualcomm, Exh. 2006, p. 2
`Apple v. Qualcomm, 2018-01277
`
`

`

`Patent Application Publication Jul. 27, 2006 Sheet 2 of 3
`
`US 2006/O165399 A1
`
`Shooting at objects
`
`Getting a position
`information of a
`zoom lens
`
`
`
`Detecting
`luminance
`automatically
`
`Calculating
`the distance
`
`Enabling a focus motor
`driving the zoom lens until
`a clear imaging is achieved
`
`
`
`Calculating the
`position of the
`ZOOm mOtOr
`
`Working out the
`distance that the
`object aparts from
`the camera
`
`
`
`Calculating the
`flash intensity
`
`
`
`
`
`Flash flashing in
`synchronization with a
`shutter curtainin open
`
`FIG 2
`
`Qualcomm, Exh. 2006, p. 3
`Apple v. Qualcomm, 2018-01277
`
`

`

`Patent Application Publication Jul. 27, 2006 Sheet 3 of 3
`
`US 2006/O165399 A1
`
`
`
`
`
`
`
`
`
`Shutter
`curtain
`
`
`
`Luminance
`SeSO
`
`10
`
`Zoom Sensor
`
`
`
`
`
`Zoom motor
`
`Focus sensor
`
`Focus motor
`
`4
`
`3
`
`FI, 3
`
`Qualcomm, Exh. 2006, p. 4
`Apple v. Qualcomm, 2018-01277
`
`

`

`US 2006/0165399 A1
`
`Jul. 27, 2006
`
`METHOD FOR AUTOMATICALLY
`COORONATING FLASH INTENSITY AND
`CAMERA SYSTEMAS THE SAME
`BACKGROUND OF THE INVENTION
`0001) 1. Field of the Invention
`0002 The present invention relates to a method for
`automatically coordinating flash intensity and camera sys
`tem as the same, particularly to a method for automatically
`coordinating flash intensity in accordance with the distance,
`the luminance and other parameters.
`0003 2. Description of the Related Arts
`0004 Flash devices are usually equipped with digital
`cameras, which provide additional light while the objects are
`not illuminated enough. In operation, different flash modes
`are applied to adjust the flash parameters. A manual flash
`mode and an auto flash mode are known as two generally
`used flash modes. When the flash device is in a manual flash
`mode, the flash flashes immediately after a shutter curtain is
`fully opened. The parameters, such as flash intensity and
`flash duration, are set prefirst. When the object is in another
`different condition, for example, the distance between the
`object and the camera has increased, or the luminance of the
`object has decreased, the camera cannot coordinate itself
`according to the changes of environment, and the parameters
`are need to be manually adjusted. However, general cus
`tomers without skilled technology cannot finish it, so most
`of the present cameras utilize the auto flash mode. In the auto
`flash mode, the camera calculates the distance that the
`objects apart from the camera and the luminance of the
`objects to coordinate the flash intensity and flash duration.
`The relationship between the parameters is given below:
`GNAL
`(1)
`Where GN represents a guide number of the flash: A
`represents an aperture of the camera; L represents a distance
`objects against the camera. The GN is a certain scale for
`luminance that the flash has emitted, and its an important
`parameter to estimate the performance of the flash. The unit
`of the GN is meter.
`0005 For measuring the distance from the object to
`camera, a distance measure unit and a photo-sensor unit are
`two kinds of generally used ways. The distance measure unit
`is a professional measuring instrument, which sends light to
`the object, calculates the flight time until it receives the
`reflected light, and multiplies the time to the speed that the
`light transmits, thereby working out the distance. Cameras
`with the distance measure units may precisely measure the
`distance, however, its too expensive for general customers.
`Meanwhile, though the cameras with the photo-sensor unit
`to measure the distance will be much cheaper, its much poor
`in precision. When operating, the flash pre-flashes, the
`camera receive the reflected light from the object, judge
`whether the object is illuminated enough. The camera com
`pares a reference exposure value with the present and works
`out the distance that the camera against the object. Although
`the cameras with photo-sensor units to measure may be
`much cheaper than ones with distance measure units, a
`pre-flashing design may exhaust the power, which bring in
`another problem.
`0006 Therefore, its essential to support a new method
`for the camera to adjust the parameters of the flash without
`above-mentioned shortcomings.
`
`BRIEF SUMMARY OF THE INVENTION
`0007 An object of the present invention is to provide an
`improved method for automatically coordinating flash inten
`sity and camera system as the same, with which the camera
`can control and coordinate the flash intensity precisely with
`low power and low cost.
`0008. The method for automatically coordinating flash
`intensity in camera in accordance with the present invention,
`comprising:
`0009 a) focusing a camera lens on an object until the
`object is clearly appeared on an image sensor,
`0010 b) sending first step value that a focus sensor has
`sensed during the focusing process to a control unit, the
`control unit transforming the first step value to distance
`information that the object apart from the camera; and
`0011 c) confirming the aperture of the camera by the
`distance, and calculating a guiding number thereby confirm
`ing a flash duration to coordinate the performance of the
`flash.
`0012. According to the method for automatically coordi
`nating flash intensity in camera, a step-distance table is
`pre-stored in the control unit for transforming the first step
`information to the distance information.
`0013. According to the present method, a camera system
`comprises a lens, an image sensor, a focus system, a focus
`sensor and a control unit. The lens is capable of controlling
`light amount that enters into camera. The focusing system is
`capable of driving the lens to focus thereby forming a clear
`image on the image sensor. The focus sensor is capable of
`sensing first step value of the focusing system during the
`focusing process, and sending the value to a control unit.
`The control unit is capable of transforming the result of the
`focusing system to a distance that the object apart from the
`camera, and configures out the guide number with the
`aperture number thereby calculating the flash intensity.
`0014) To compare with the conventional invention, the
`present invention establishes a relationship table to confirm
`the parameters of the flash. When the camera focusing on the
`object, the focus sensor senses the steps that the focus motor
`has worked. With the step result, the control unit may find
`out the present distance that the object apart from the camera
`thereby working out the guide number to coordinate the
`aperture. The present camera systems without neither a
`professional measurement tool nor an additional pre-flash,
`may measure the distance that the objects apart from the
`camera, and low down the cost and power consumption. The
`camera systems may also precisely control the flash intensity
`thereby coordinating the exposure effect.
`0015. Other objects, advantages and novel features of the
`invention will become more apparent from the following
`detailed description of a preferred embodiment when taken
`in conjunction with the accompanying drawings.
`
`BREIF DESCRIPTION OF THE DRAWINGS
`0016 FIG. 1 is a flow chart according to the present
`invention, showing a camera automatically coordinating
`flash intensity;
`0017 FIG. 2 is a flow chart showing an applying of the
`present invention in Zoom camera; and
`
`Qualcomm, Exh. 2006, p. 5
`Apple v. Qualcomm, 2018-01277
`
`

`

`US 2006/0165399 A1
`
`Jul. 27, 2006
`
`0018 FIG. 3 is a block diagram showing a structure of a
`camera with a function of automatically adjusting the flash
`intensity.
`
`DETAILED DESCRIPTION OF THE
`PREFFERRED EMBODIMENTS
`0019. A Zoom digital camera is taken to explain the
`present invention. Referring to FIG. 1, a method for auto
`matically coordinating flash intensity according to the
`present invention, comprises:
`0020 Step a, focusing with a focus motor. The focus
`motor is actually a step motor, which is capable of providing
`
`clearly appeared. The focus sensor senses the first step value
`that the focus motor has worked and sent the first step value
`to the control unit. The distance may be achieved by
`comparing the first step value with the pre-stored step
`distance table. The control unit then works out a guide
`number and a flash duration with the distance information,
`the aperture, and the expression (1), and coordinates the
`flash with these parameters.
`0024. The referred pre-stored step-distance table in con
`trol unit can be achieved by times of experiments. The
`step-distance table according to a certain digital camera is
`described in a following table-1.
`
`Zoom Lens
`
`Zoom ratio
`Aperture
`
`TABLE-1
`
`Step and the corresponding distance
`
`f (mm)
`
`Open
`
`Contract Co
`
`5 m
`
`2 m
`
`1.5 m
`
`1 m O.8 m 0.6 m 0.5 m O.4 m O.3 m O.O993 m
`
`f1
`f2
`f3
`f\.
`f5
`f6
`
`123
`
`1.OO
`1.27
`1.54
`1.89
`2.29
`2.80
`
`4.76
`2.91
`6.OO
`S.27
`3.22
`7.621
`5.77
`9.252 3.52
`6.41
`11353 3.91
`7.11
`13.731
`4.3S
`16.797 4.90 8.00
`
`126
`82
`49
`16
`-10
`-27
`
`129
`86
`S4
`24
`2
`-7
`
`131
`91
`62
`37
`21
`2O
`
`134
`94
`67
`44
`31
`36
`
`137
`100
`76
`58
`52
`66
`
`141
`1 OS
`83
`68
`67
`88
`
`14S
`112
`94
`85
`92
`124
`
`151
`119
`103
`99
`112
`152
`
`161
`128
`117
`120
`142
`194
`
`264
`144
`141
`156
`191
`262
`
`uniform momentum at intervals and driving the Subject
`moving at steps. The focus motor drives a lens to enable the
`movement of it. In operation, the lens shoots at the object.
`The camera controls the focus motor to drive the lens, and
`judges whether the image is clearly appeared on a screen.
`0021 Step b, calculating steps that the focus motor
`works, and looking through a pre-stored table for a distance
`that the object apart from the camera. The pre-stored table
`relates to a relationship of the corresponding step-distance,
`of which the “step’ represents a first step value, which is
`how many steps the focus motor has worked, and the
`“distance' represents how far the object apart from the
`camera. When the image is clearly appeared, a focus sensor
`senses the “step’ and sent it to a control unit. The control
`unit calculates the “distance' by comparing the first step
`value with the pre-stored table in it.
`0022 Step c, calculating a result to coordinate the flash
`intensity with the distance and the present focal length.
`0023. Also referring to FIG. 2, a flow chart of the present
`invention when applying to a Zoom digital camera is shown.
`A Zoom motor is controlled to driver the Zoom lens on an
`axis to coordinate the focal length. Second step value that
`the Zoom motor has worked during the process of coordi
`nation is transformed to position information of the Zoom
`lens. The position information is sensed by a Zoom sensor
`and is sent to a control unit. A table relating to a relationship
`of the position-focal length is pre-stored in the control unit,
`wherein a present focal length may be achieved by compar
`ing the pre-stored table with the position result. An aperture
`is achieved by the following expression:
`(2)
`A=FAD
`Where A represents the aperture, F represents the focal
`length, and D represents an F-stop. The focus motor is
`controlled to drive the lens until an image of the object is
`
`0025. As is described in the table-1, the second step value
`that the Zoom motor has worked corresponds with the
`positions of the Zoom lens, which alternates from fl to fo
`between “tele' and “wide'. A certain position of the Zoom
`lens thereby confirms a corresponding focal length and
`aperture. Each focal length corresponds a plurality of cor
`responding first step value that the focus motor has worked
`and distance. The distance that the object against the camera
`is determined on the basis of the focal length and the first
`step value. In operation, the relationship table is pre-stored
`in the control unit, the second step value is achieved with the
`Zoom sensor, and the distance may be found out in the
`relationship table with the first step value. In another hand,
`the second step value of the Zoom motor confirms the
`position of the Zoom lens. The position of the Zoom lens
`confirms a corresponding focal length and aperture in the
`relationship table. Therethrough, the control unit may cal
`culate the guide number with expression (1) to coordinates
`the flash intensity.
`0026. For a fixed focal lens camera, as the focal length is
`unchangeable, the distance that the object apart from the
`camera may be found out in the relationship table with the
`first step value. With these parameters, the control unit may
`calculate the guide number to coordinate the flash. It will be
`understood that it is more proper for the present invention to
`apply in a fixed focal lens camera, since the present inven
`tion is advanced in reduce the cost and power cost.
`0027. The method for automatically coordinating flash
`intensity in accordance with the present invention further
`comprises a step of luminance detection. The luminance
`detection is to detect the luminance information of environ
`ment objects with an Automatic Exposure, and the detected
`luminance information is sent to the control unit. A reference
`value of the luminance is pre-stored in the control unit and
`
`Qualcomm, Exh. 2006, p. 6
`Apple v. Qualcomm, 2018-01277
`
`

`

`US 2006/0165399 A1
`
`Jul. 27, 2006
`
`is used to compare with the detected luminance information.
`Then, the control unit coordinates the flash intensity with the
`compare result.
`0028 Referring to FIG. 3, a block diagram of structures
`of a camera system with the function of automatically
`adjusting the flash intensity is shown. The camera is com
`posed of a control unit 1, a lens 2, a focus motor 3, a focus
`sensor 4, an image sensor 5, and a flash 6. The lens 2 may
`coordinate the aperture to control the light amount that
`enters the camera. The control unit 1 guides the focus motor
`3 to drive the lens 2 to focus until a clear image appeared on
`the image sensor 5 is achieved. The focus sensor 4 senses the
`first step value that the focus motor 3 has worked when it is
`adjusting the focal length, and the first step value is sent to
`the control unit 1. A table is pre-stored in the control unit 1,
`which relates to relationships of the first step value that the
`focus motor 3 has worked and the distance that the object
`apart from the camera. Parameters such as aperture of the
`lens 2, flash intensity and guide number of the flash 6, may
`be correspondingly found out in the table. These parameters
`are used to control the flash 6 to ensure proper light amount
`that the flash 6 flashes in synchronization with a shutter
`curtain 7 opening.
`0029. The camera system also comprises a luminance
`sensor 8, which senses the luminance information of Sur
`rounding objects and sends the luminance information to the
`control unit 1. A reference value of the luminance is pre
`stored in the control unit 1, and the luminance information
`that the luminance sensor 8 sensed is used to compare with
`the reference value for coordinate the flash intensity.
`0030. While a Zoom camera is referred, the camera
`system further comprises a Zoom motor 9 and a Zoom sensor
`10. The Zoom motor 9 may drive the lens 2 to coordinate the
`focal length. The Zoom sensor 10 senses the second step
`value that the Zoom motor 9 has worked and sends the value
`to the control unit 1. The control unit 1 finds out the
`corresponding distance with the pre-stored step-distance
`table thereby configuring out the aperture of the camera.
`0031. The present invention as is described hereinabove
`Substantially makes use of the step-distance table to confirm
`the parameters of the flash. When the camera focusing on the
`object, the focus sensor senses the first step value that the
`focus motor has worked. With the step result, the control unit
`may find out the present distance that the object apart from
`the camera thereby working out the guide number to coor
`dinate the aperture. The present Camera systems without
`neither a professional measurement tool nor an additional
`pre-flash, may easily measure the distance that the objects
`apart from the camera, and low down the cost and power
`consumption. The camera systems may also precisely con
`trol the flash intensity thereby coordinating the exposure
`effect.
`0032. It will be understood that the focus sensor 4 (the
`Zoom sensor 10 as well) and the control unit 1 may actually
`be a DSP (Digital Signal Processor), and the image sensor 5
`may actually be a CCD or CMOS (Complementary Metal
`Oxide Semiconductor Sensor).
`0033. It will be understood that the invention may be
`embodied in other specific forms without departing from the
`spirit or central characteristics thereof. The present
`examples and embodiments, therefore, are to be considered
`
`in all respects as illustrative and not restrictive, and the
`invention is not be limited to the details given herein.
`
`We claim:
`1. A method for automatically coordinating flash intensity
`in camera, comprising:
`a) focusing a camera lens on an object until the object is
`clearly appeared on an image sensor;
`b) sending a first step value that a focus sensor has sensed
`to a control unit, the control unit transforming the first
`step value to a distance information that the object apart
`from the camera; and
`c) confirming the aperture of the camera by the distance,
`and calculating a guiding number thereby confirming a
`flash duration to coordinate the performance of the
`flash.
`1. The method for automatically coordinating flash inten
`sity in camera as claimed in claim 1, wherein a step-distance
`table is pre-stored in the control unit for transforming the
`first step value to the distance.
`2. The method for automatically coordinating flash inten
`sity in camera as claimed in claim 1, wherein when the
`method is applied in Zoom camera, a Zoom sensor senses a
`position information of a Zoom lens, sends the information
`to the control unit, and the control unit transforms the
`information to a focal length and calculating the aperture
`with an expression “A=F/D', of which A represents the
`aperture, F represents the focal length, and D represents an
`F-stop.
`3. The method for automatically coordinating flash inten
`sity in camera as claimed in claim 3, wherein a position
`focal length table is pre-stored in the control unit for
`transforming the position information to the focal length.
`4. The method for automatically coordinating flash inten
`sity in camera as claimed in claim 2 or 4, wherein the
`method further comprises a step of luminance detection to
`detect luminance information of environment objects with a
`luminance sensor, and a detection result is sent to the control
`unit to compare with a pre-stored reference value, then, the
`control unit coordinates the flash intensity with the compare
`result.
`5. The method for automatically coordinating flash inten
`sity in camera as claimed in claim 2 or 4, wherein the
`pre-stored table may be achieved by times of experiments.
`6. The method for automatically coordinating flash inten
`sity in camera as claimed in 1 or 3, wherein a CMOS
`(complementary metal oxide semiconductor sensor) is
`applied as a focus system, and the said result is a value of
`steps that the focus/Zoom motor has worked.
`7. The method for automatically coordinating flash inten
`sity in camera as claimed in 1 or 3, wherein a manual focus
`system is applied in the camera, and result is a value that
`how many circles the focus button has turned.
`8. A camera system with a function of automatically
`adjusting the flash intensity, comprising:
`a) a lens capable of controlling light amount that enters
`into camera;
`b) an image sensor,
`c) a focusing system capable of driving the lens to focus
`thereby forming a clear image on the image sensor,
`
`Qualcomm, Exh. 2006, p. 7
`Apple v. Qualcomm, 2018-01277
`
`

`

`US 2006/0165399 A1
`
`Jul. 27, 2006
`
`d) a focus sensor capable of sensing first step value of the
`focusing system during the focusing process, and send
`ing the value to a control unit; and
`e) the control unit capable of transforming the result of the
`focusing system to a distance that the object apart from
`the camera, and configuring out the guide number with
`the aperture number thereby calculating the flash inten
`sity.
`9. The camera system with a function of automatically
`adjusting the flash intensity as claimed in claim 9, wherein
`a step-distance table is pre-stored in the control unit for
`transforming the result to the distance that object apart from
`the camera.
`10. The camera system with a function of automatically
`adjusting the flash intensity as claimed in claim 10, wherein
`the camera system further comprises a Zoom motor for
`coordinating the focal length of the lens.
`11. The camera system with a function of automatically
`adjusting the flash intensity as Claimed in claim 11, wherein
`the camera system further comprises a Zoom sensor for
`sensing the position of the lens and sending the result to the
`control unit.
`12. The camera system with a function of automatically
`adjusting the flash intensity as claimed in claim 12, wherein
`the focal length may be achieved by a pre-stored position
`focal length table, so that the control unit capable of calcu
`lating the aperture number.
`
`13. The camera system with a function of automatically
`adjusting the flash intensity as claimed in claim 9 or 13,
`wherein the camera system further comprises a luminance
`sensor, which is capable of sensing the luminance of the
`Surroundings and sending the result to the control unit.
`14. The camera system with a function of automatically
`adjusting the flash intensity as claimed in claim 14, wherein
`a reference luminance value is pre-stored in the control unit
`for comparing with the luminance result enable the control
`unit coordinate the flash intensity.
`15. The camera system with a function of automatically
`adjusting the flash intensity as claimed in claim 9 or 13,
`wherein the table pre-stored in the control unit is achieved
`by times of experiments.
`16. The camera systems with a function of automatically
`adjusting the flash intensity as claimed in 9 or 13, wherein
`a CMOS is applied in as a focus system, and the said result
`is a value of steps that the focus/Zoom motor has worked.
`17. The camera system with a function of automatically
`adjusting the flash intensity in claim 9 or 13, wherein a
`manual focus system is applied in the camera, and result is
`a value that how many circles that the focus button has
`turned.
`
`Qualcomm, Exh. 2006, p. 8
`Apple v. Qualcomm, 2018-01277
`
`