IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0344087
(2012-01-05)
|
등록번호 |
US-RE44499
(2013-09-17)
|
우선권정보 |
JP-2006-181670 (2006-06-30) |
발명자
/ 주소 |
- Inoue, Daisuke
- Takahashi, Hidekazu
|
출원인 / 주소 |
|
대리인 / 주소 |
Fitzpatrick, Cella, Harper & Scinto
|
인용정보 |
피인용 횟수 :
0 인용 특허 :
9 |
초록
▼
A low cost and high speed AF sensor is realized by increasing AF speed without providing a sensor dedicated for a large de-focusing AF. The AF sensor has two sensors each including a plurality of photoelectric conversion elements and detects a focus based on signals read from the sensors. The two se
A low cost and high speed AF sensor is realized by increasing AF speed without providing a sensor dedicated for a large de-focusing AF. The AF sensor has two sensors each including a plurality of photoelectric conversion elements and detects a focus based on signals read from the sensors. The two sensors each includes a plurality of linear sensors 11 to 13. The two sensors each has a plurality of accumulation controlling circuits (PB detection circuits 14 to 16 and accumulation decision circuits 17 to 19) for controlling the accumulation time of the photoelectric conversion elements and a plurality of scanning circuits (shift registers 21 to 23) for reading out output signals from the photoelectric conversion elements. The AF sensor has a first mode in which the accumulation time of each linear sensor in the two sensors is independently controlled to independently read a signal output and a second mode in which the accumulation time of the linear sensors in the two sensors is collectively controlled to read a signal output.
대표청구항
▼
1. A focus detection apparatus of phase difference detection type having a sensor for a standard portion and a sensor for a reference portion, each of the sensors including a plurality of photoelectric conversion elements, and detecting a focus based on signals read out from the sensor for the stand
1. A focus detection apparatus of phase difference detection type having a sensor for a standard portion and a sensor for a reference portion, each of the sensors including a plurality of photoelectric conversion elements, and detecting a focus based on signals read out from the sensor for the standard portion and the sensor for the reference portion, wherein each of the sensor for the standard portion and the sensor for the reference portion includes a plurality of linear sensors, and includes a plurality of accumulation controlling circuits for controlling the accumulation time of the photoelectric conversion elements and a plurality of scanning circuits for reading signals output from the photoelectric conversion elements, and wherein the focus detection apparatus comprises: a first driving unit for executing a first mode in which the accumulation time of the plurality of linear sensors in each of the sensor for the standard portion and the sensor for the reference portion is independently controlled and signals are independently output; anda second driving unit for executing a second mode such that the accumulation time of the plurality of linear sensors in each of the sensor for the standard portion and the sensor for the reference portion is collectively controlled to read out output signals from the sensors. 2. The focus detection apparatus of phase difference detection type according to claim 1, wherein the first driving unit independently drives the plurality of scanning circuits when executing the first mode, and wherein the second driving unit sequentially drives the plurality of scanning circuits when executing the second mode. 3. The focus detection apparatus of phase difference detection type according to claim 1, wherein the plurality of accumulation controlling circuits detect the maximum and the minimum value of signals output from a plurality of the photoelectric conversion elements to be arranged and control the accumulation time of the photoelectric conversion elements based on the difference between the maximum and the minimum value to be detected so that the contrast of luminance of object image can be a predetermined value. 4. The focus detection apparatus of phase difference detection type according to claim 1, wherein the plurality of linear sensors are arranged closely adjacent to each other. 5. The focus detection apparatus of phase difference detection type according to claim 4, wherein the plurality of linear sensors are arranged so as to align arrangement directions thereof. 6. A camera system comprising the focus detection apparatus of phase difference detection type according to claim 1. 7. A method of driving a focus detection apparatus of phase difference detection type having a sensor for a standard portion and a sensor for a reference portion, each of the sensors including a plurality of photoelectric conversion elements, and detecting a focus based on signals read from the sensor for the standard portion and the sensor for the reference portion, wherein each of the sensor for the standard portion and the sensor for the reference portion includes a plurality of linear sensors, and includes a plurality of accumulation controlling circuits for controlling the accumulation time of the plurality of linear sensors and a plurality of scanning circuits for reading signals output from the plurality of linear sensors, and wherein the method of driving the focus detection apparatus comprises steps of: executing a first mode in which the accumulation time of the plurality of linear sensors in each of the sensor for the standard portion and the sensor for the reference portion is independently controlled and signals are independently output; andexecuting a second mode in which the accumulation time of the plurality of linear sensors in each of the sensor for the standard portion and the sensor for the reference portion is collectively controlled to read out output signals from the sensors. 8. The method of driving the focus detection apparatus of phase difference detection type according to claim 7, wherein the executing the first mode independently drives the plurality of scanning circuits, and wherein the executing the second mode sequentially drives the plurality of scanning circuits. 9. The focus detection apparatus according to claim 1, wherein each of the accumulation controlling circuits comprises: a plurality of peak/bottom detection circuits, wherein each of the peak/bottom detection circuits detects a peak signal or a bottom signal outputted from one of the plurality of photoelectric conversion elements;a plurality of accumulation decision circuits, wherein each of the accumulation decision circuits is adapted to receive a signal from an output node of a corresponding peak/bottom detection circuit and to control an accumulation time of a corresponding photoelectric conversion element in response to the signal from the corresponding peak/bottom detection circuit; andconnection means for selectively connecting the output nodes of the plurality of peak/bottom detection circuits with each other electrically, such that one of the plurality of accumulation decision circuits receives the signals from the plurality of peak/bottom detection circuits. 10. The focus detection apparatus according to claim 9, wherein, in the first mode, the connection means connects the output node of each of the plurality of peak/bottom detection circuits to a respective one of the accumulation decision circuits. 11. The focus detection apparatus according to claim 1, further comprising a plurality of scanning circuits for reading out the signals from the photoelectric conversion elements, wherein each of the scanning circuits comprises multiple-step flip-flops connected in series and, in the first mode, independently receives a start pulse on a scanning circuit basis. 12. The focus detection apparatus according to claim 1, further comprising a plurality of scanning circuits for reading out the signals from the photoelectric conversion elements, wherein the plurality of scanning circuits are independently driven in the first mode, andwherein the plurality of scanning circuits are sequentially driven in the second mode. 13. The focus detection apparatus according to claim 9, wherein each of the peak/bottom detection circuits comprises: a first amplifier circuit for amplifying the signal from one of the photoelectric conversion elements;an NMOS source follower circuit having a constant current source load and inputted with a signal from the first amplifier circuit;a second amplifier circuit for amplifying the signal from the photoelectric conversion element; anda PMOS source follower circuit having a constant current source load and inputted with a signal from the second amplifier circuit, andwherein one of the accumulation decision circuits determines a difference between an output from the NMOS source follower circuit and an output from the PMOS source follower circuit. 14. The method according to claim 7, wherein each of the accumulation controlling circuits comprises: a plurality of peak/bottom detection circuits, wherein each of the peak/bottom detection circuits detects a peak signal or a bottom signal outputted from one of the plurality of photoelectric conversion elements;a plurality of accumulation decision circuits, wherein each of the accumulation decision circuits is adapted to receive a signal from an output node of a corresponding peak/bottom detection circuit and to control an accumulation time of a corresponding photoelectric conversion element in response to the signal from the corresponding peak/bottom detection circuit; andconnection means for selectively connecting the output nodes of the plurality of peak/bottom detection circuits with each other electrically, such that one of the plurality of accumulation decision circuits receives the signals from the plurality of peak/bottom detection circuits. 15. The method according to claim 14, wherein, in the first mode, the output node of each of the plurality of peak/bottom detection circuits is connected to a respective one of the accumulation decision circuits. 16. The method according to claim 15, wherein the focus detection apparatus further comprises a plurality of scanning circuits for reading out the signals from the photoelectric conversion elements, and each of the scan circuits comprises multiple-step flip-flops connected in series, wherein each of the scanning circuits independently receives a start pulse in the first mode. 17. The method according to claim 15, wherein the focus detection apparatus further comprises a plurality of scanning circuits for reading out the signals from the photoelectric conversion elements, wherein the plurality of scanning circuits are independently driven in the first mode, andwherein the plurality of scanning circuits are sequentially driven in the second mode. 18. A focus detection apparatus having a plurality of sensors each having a plurality of photoelectric conversion elements, the focus detection apparatus comprising: a plurality of peak/bottom detection circuits, wherein each of the peak/bottom detection circuits detects a peak signal or a bottom signal outputted from one of the plurality of photoelectric conversion elements;a plurality of accumulation decision circuits, wherein each of the accumulation decision circuits is adapted to receive a signal from an output node of a corresponding peak/bottom detection circuit and to control an accumulation time of a corresponding photoelectric conversion element in response to the signal from the corresponding peak/bottom detection circuit; andconnection means for selectively connecting the output nodes of the plurality of peak/bottom detection circuits with each other electrically, such that one of the plurality of accumulation decision circuits receives the signals from the plurality of peak/bottom detection circuits. 19. The focus detection apparatus according to claim 18, wherein the connection means has a mode for connecting the output node of each of the plurality of peak/bottom detection circuits to a respective one of the accumulation decision circuits. 20. The focus detection apparatus according to claim 19, further comprising a plurality of scanning circuits for reading out the signals from the photoelectric conversion elements, wherein each of the scanning circuits comprises multiple-step flip-flops connected in series and, in the mode, independently receives a start pulse on a scanning circuit basis. 21. The focus detection apparatus according to claim 19, further comprising a plurality of scanning circuits for reading out the signals from the photoelectric conversion elements, wherein the plurality of scanning circuits are independently driven when the mode is executed, andwherein the plurality of scanning circuits are sequentially driven when the output nodes are connected. 22. The focus detection apparatus according to claim 18, wherein each of the peak/bottom detection circuits comprises: a first amplifier circuit for amplifying the signal from one of the photoelectric conversion elements;an NMOS source follower circuit having a constant current source load and inputted with a signal from the first amplifier circuit;a second amplifier circuit for amplifying the signal from the photoelectric conversion element; anda PMOS source follower circuit having a constant current source load and inputted with a signal from the second amplifier circuit, andwherein one of the accumulation decision circuits determines a difference between an output from the NMOS source follower circuit and an output from the PMOS source follower circuit. 23. The focus detection apparatus according to claim 18, wherein the plurality of photoelectric conversion elements included in each of the plurality of sensors are arranged in a same alignment direction. 24. The focus detection apparatus according to claim 18, wherein the plurality of sensors are connected to each other in a straight line, and have ineffective areas between the sensors where the signals from the photoelectric conversion elements are not used for a control of the accumulation time.
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