CN100581220C - Image-pickup apparatus and focus control method for the same - Google Patents

Abstract

An image-pickup apparatus is disclosed which can prevent focus control from being performed on the basis of incorrect information on an object distance externally measured. The image-pickup apparatus includes a first detector which produces first information corresponding to a contrast state of a picked-up image, a second detector which receives light from an object to detect second information corresponding to a distance to the object, and a controller which performs focus control by using the first information and the second information. The controller performs the focus control by using the first information without using the second information when a light-receiving luminance level in the second detector is lower than a first value.

Description

The focus control method of picture pick-up device and picture pick-up device

Technical field

The present invention relates to picture pick-up devices such as video camera and digital stillcamera, relate in particular to the focusing control in this class picture pick-up device.

Background technology

In automatic focusing (AF) control of picture pick-up devices such as video camera, the main TV-AF method of using, this method comprise corresponding AF evaluation value signal of acutance (contrast state) that uses imaging apparatus to produce vision signal, generation and vision signal (photographic images) and the position of searching for the focusing lens of AF evaluation value signal maximum.

Another kind of AF method is outside distance-finding method (an outside phase difference detection method), in the method, be independent of pick-up lens and range finding (range measurement) transducer be set to detect distance apart from subject, focusing (in-focus based on detected distance calculation focusing lens, promptly to good burnt) position, and focusing lens moved to this focal position.

Outside distance-finding method comprises the luminous flux (luminous flux) from subject is divided into two parts that a pair of light receiving element array (line sensor (line sensor)) receives these two parts successively.The difference of detection between this image that forms on to line sensor is phase difference, uses this phase difference to determine the subject distance by triangulation (triangulation), and focusing lens is moved to focal position with respect to this subject distance.

In order to utilize the high accuracy of focusing in the TV-AF method and the quick focusing in the outside distance-finding method, developed mixing AF method by making up these two kinds of AF methods, for example, a kind of mixing AF method is disclosed in TOHKEMY 2005-84426 communique.In TOHKEMY 2005-84426 communique in the disclosed mixing AF method, when being judged as because the low-light level of subject or low contrast when causing the TV-AF method to realize focusing, utilize phase difference detection method to obtain focusing.

5 (1993)-No. 64056 communiques of Japanese kokai publication hei disclose another kind of mixing AF method, in the method, with the TTL phase difference detection method focusing lens is driven near the focal position, with higher accuracy focusing lens is driven into focal position with the TV-AF method then.TOHKEMY 2005-234325 communique discloses another kind of mixing AF method, in the method, in the control of focusing, select in these two kinds of methods any one based on the variable quantity of the signal that in TV-AF method and outside range finding phase difference detection method, is produced.

In being used in combination the mixing AF of TV-AF method and outside distance-finding method,, then can't provide correct subject range information if between distance measuring sensor and subject, there is the barrier of non-subject.Generally distance measuring sensor is placed near pick-up lens the parallax minimum between the visual field (the detection visual field) that is used to detect with the shooting visual field and the distance measuring sensor that is used in by the pick-up lens photographic images.In this case, for example, user's hand is placed on the light that blocks from subject between distance measuring sensor and the subject usually and enters distance measuring sensor.Block photoconduction from the subject to the distance measuring sensor and cause and to realize that focusing maybe can not realize focusing the longer time, thereby can not make full use of the quick focusing that the outside distance-finding method that is used in combination with the TV-AF method produces.

In order to address this problem, TOHKEMY 2005-241805 communique discloses a kind of picture pick-up device, in this equipment, when a pair of light receiving element array in the distance measuring sensor provides the disparity threshold amount or more exports, utilize the TV-AF method to replace the control of focusing of outside distance-finding method.

When one in a pair of light receiving element array in the distance measuring sensor was only covered by user's barriers such as hand, TOHKEMY 2005-241805 communique disclosed method was effective.Yet, if for example user's hand has covered a pair of light receiving element array similarly, from this to the difference between the output of light receiving element array less than threshold value, thereby can utilize the control of focusing of outside distance-finding method.In other words, may be based on the control of focusing of incorrect subject range information, thereby cause need be longer time obtain focus state and maybe can not obtain focus state.

Summary of the invention

The invention provides a kind of can preventing based on the picture pick-up device of control and the focus control method of this picture pick-up device of focusing from externally measured incorrect information about the subject distance.

According to an aspect, the invention provides a kind of picture pick-up device, comprising: first detector, it produces the corresponding first information of contrast state with photographic images; Second detector, it receives from the light of subject to detect and corresponding second information of distance to subject; And controller, it uses the control of focusing of the described first information and described second information.When the light-receiving luminance level in described second detector was lower than first value, described controller used the described first information and does not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of picture pick-up device, comprising: first detector, it produces the corresponding first information of contrast state with photographic images; Second detector, it comprises at least one pair of light receiving element array, each described light receiving element array comprises a plurality of light receiving elements, described second detector calculating is from the correlation of reception from the signal of the described light receiving element array output of the light of subject, to detect and corresponding second information of distance that arrives subject; And controller, it uses the control of focusing of the described first information and described second information.When described correlation was lower than first value, described controller used the described first information and does not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of picture pick-up device, comprising: first detector, it produces the corresponding first information of contrast state with photographic images; Second detector, it receives from the light of subject to detect and corresponding second information of distance to subject; And controller, it uses the control of focusing of the described first information and described second information.When with the corresponding described distance of described second information when nearer than first distance, described controller uses the described first information and does not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of focus control method of picture pick-up device, comprising: obtain step with the corresponding first information of contrast state of photographic images; Use reception from the detector acquisition of the light of subject and the step of corresponding second information of distance that arrives subject; And controlled step, it uses the control of focusing of the described first information and described second information.Described controlled step comprises: when the light-receiving luminance level in the described detector is lower than first value, uses the described first information and do not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of focus control method of picture pick-up device, comprise the steps: to obtain step with the corresponding first information of contrast state of photographic images; By calculating from the correlation of reception from the signal of at least one pair of light receiving element array output of the light of subject, obtain and arrive the step of corresponding second information of distance of subject, each described light receiving element array comprises a plurality of light receiving elements; And controlled step, it uses the control of focusing of the described first information and described second information.Described controlled step comprises: when described correlation is lower than first value, uses the described first information and do not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of focus control method of picture pick-up device, comprise the steps: to obtain step with the corresponding first information of contrast state of photographic images; Use reception from the detector acquisition of the light of subject and the step of corresponding second information of distance that arrives subject; And controlled step, it uses the control of focusing of the described first information and described second information.Described controlled step comprises: when with the corresponding described distance of described second information when nearer than first distance, use the described first information and do not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of picture pick-up device, comprising: first detector, it produces and the corresponding first information of contrast state that uses the photographic images that imaging apparatus produced; Second detector, it receives from the light of subject to detect and corresponding second information of distance to subject; The focusing controller, it uses the control of focusing of the described first information and described second information; And the aperture controller, its control is used to regulate the aperture of the light quantity that enters described imaging apparatus.When according to described aperture controller the variation of the state of a control of described aperture not being changed about the information of the light-receiving state of described second detector, described focusing controller uses the described first information and does not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of picture pick-up device, comprising: first detector, it produces the corresponding first information of contrast state with photographic images; Second detector, it receives from the light of subject to detect and corresponding second information of distance to subject; The focusing controller, it uses the control of focusing of the described first information and described second information; And the color balance controller, it controls the color balance of described photographic images.When according to described color balance controller the variation of the state of a control of described color balance not being changed about the information of the light-receiving state of described second detector, described focusing controller uses the described first information and does not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of picture pick-up device, comprising: first detector, it produces the corresponding first information of contrast state with photographic images; Second detector, it receives from the light of subject to detect and corresponding second information of distance to subject; The focusing controller, it uses the control of focusing of the described first information and described second information; And rocking detector, it detects rocking of described picture pick-up device.When the information about the light-receiving state of described second detector did not change according to the described variation of rocking detected state of rocking detector, described focusing controller used the described first information and does not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of focus control method of picture pick-up device, comprising: the step of obtaining and use the corresponding first information of contrast state of the photographic images that imaging apparatus produces; Use reception from the detector acquisition of the light of subject and the step of corresponding second information of distance that arrives subject; The focusing controlled step, it uses the control of focusing of the described first information and described second information; And the aperture controlled step, its control is used to regulate the aperture of the light quantity that enters described imaging apparatus.Described focusing controlled step comprises: when according to described aperture controlled step the variation of the state of a control of described aperture not being changed about the information of the light-receiving state of described detector, use the described first information and do not use the control of focusing of described second information.

According to another kind of aspect, a kind of focus control method of picture pick-up device is provided, comprising: obtain step with the corresponding first information of contrast state of photographic images; Use reception from the detector acquisition of the light of subject and the step of corresponding second information of distance that arrives subject; The focusing controlled step, it uses the control of focusing of the described first information and described second information; And the color balance controlled step, it controls the color balance of described photographic images.Described focusing controlled step comprises: when according to described color balance controlled step the variation of the state of a control of described color balance not being changed about the information of the light-receiving state of described detector, use the described first information and do not use the control of focusing of described second information.

According to another kind of aspect, the invention provides a kind of focus control method of picture pick-up device, comprising: obtain step with the corresponding first information of contrast state of photographic images; Use reception from the detector acquisition of the light of subject and the step of corresponding second information of distance that arrives subject; The focusing controlled step, it uses the control of focusing of the described first information and described second information; And rocking the detection step, it detects rocking of described picture pick-up device.Described focusing controlled step comprises: when not rocking the variation of rocking detected state that detects in the step when not changing according to described about the information of the light-receiving state of described detector, use the described first information and do not use the control of focusing of described second information.

From below with reference to the accompanying drawing description of a preferred embodiment, other purpose of the present invention and feature will be obviously.

Description of drawings

Fig. 1 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 1.

Fig. 2 is the flow chart that the process of the AF control among the embodiment 1 is shown.

Fig. 3 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 2.

Fig. 4 is the flow chart that the process of the AF control among the embodiment 2 is shown.

Fig. 5 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 3.

Fig. 6 is the flow chart that the process of the AF control among the embodiment 3 is shown.

Fig. 7 illustrates the principle of the TV-AF among the embodiment.

Fig. 8 is the flow chart that the control procedure of the TV-AF among the embodiment is shown.

How Fig. 9 illustrates in an embodiment measuring distance.

Figure 10 illustrates the waveform of the picture signal that is used to calculate correlation in an embodiment.

Figure 11 illustrates the notion of the correlation calculations among the embodiment 2.

Figure 12 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 4.

Figure 13 is the flow chart that the process of the AF control among the embodiment 4 is shown.

Figure 14 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 5.

Figure 15 is the flow chart that the process of the AF control among the embodiment 5 is shown.

Figure 16 is illustrated in the example of the variation of the light-receiving luminance level in the outside distance measuring sensor unit among the embodiment 4.

Figure 17 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 6.

Figure 18 is the flow chart that the process of the AF control among the embodiment 6 is shown.

Figure 19 illustrates the curve chart of the relation between the light-receiving luminance level that is used for being illustrated in embodiment 6 aperture control signals and the outside distance measuring sensor unit.

Figure 20 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 7.

Figure 21 is the flow chart that the process of the AF control among the embodiment 7 is shown.

Figure 22 is the block diagram that illustrates as the structure of the video camera of embodiments of the invention 8.

Figure 23 is the flow chart that the process of the AF control among the embodiment 8 is shown.

Embodiment

Following with reference to description of drawings the preferred embodiments of the present invention.

Embodiment 1

Fig. 1 illustrates the structure as the video camera of embodiments of the invention 1 (picture pick-up device).Though in conjunction with video camera explanation embodiment 1, optional embodiment of the present invention comprises other picture pick-up devices such as digital stillcamera.This is applicable to the embodiment 2～8 of explanation after a while.

In Fig. 1, Reference numeral 102 illustrates fixed lens, and 103 illustrate aperture, and 104 illustrate and can move focusing lens to focus along optical axis direction.Fixed lens 102, aperture 103 and focusing lens 104 constitute image pickup optical system.

Reference numeral 111 illustrates the imaging apparatus that is formed by ccd sensor, cmos sensor etc., and it is as photo-electric conversion element.Luminous flux from subject passes through fixed lens 102, aperture 103 and focusing lens 104, forms image then on imaging apparatus 111.The subject image of exporting 111 pairs of formation of imaging apparatus of image pickup signal subsequently carries out opto-electronic conversion.

Reference numeral 124 illustrates the focusing drive circuit that drives focusing lens 104 along optical axis direction.Focusing drive circuit 124 comprises the drive circuit of stepper motor, DC motor, vibration types of motors and voice coil motor actuators such as (voice coil motor) and drive actuator.

Reference numeral 112 illustrates the camera signal treatment circuit that the image pickup signal from the output of imaging apparatus 111 is converted to video standard signals (vision signal) such as NTSC signal.Reference numeral 201 illustrates the register of video signal recording on recording mediums such as tape, CD and semiconductor memory from 112 outputs of camera signal treatment circuit.

Reference numeral 202 illustrates the monitor that is for example formed by LCD, shows from the vision signal of camera signal treatment circuit 112 outputs as video.

Reference numeral 121 illustrates the focus signal testing circuit as first detector.Focus signal testing circuit 121 extracts high fdrequency component or extracts the luminance difference component that produces from high fdrequency component (between the minimum and maximum value of luminance level poor) from the luminance signal component of the vision signal of camera signal treatment circuit 112 output, to produce the AF evaluation value signal as the first information.

The AF evaluation value signal is represented based on the acutance (contrast state) from the video (photographic images) of the video signal generating of imaging apparatus 111.Acutance depends on the focus state of image pickup optical system, thereby the AF evaluation value signal is represented the focus state of image pickup optical system.

Reference numeral 131 illustrates the AF control circuit that is arranged in the microcomputer (CPU) 130.Be responsible for the operation of whole video camera as the microcomputer 130 of controller.AF control circuit 131 control of focusing, in focusing control, AF control circuit 131 control focusing drive circuits 124 are with mobile focusing lens 104.Particularly, AF control circuit 131 is with TV-AF method (the being designated hereinafter simply as TV-AF) control of focusing, and with outside range finding (outside phase difference detection) method (being designated hereinafter simply as outside range finding AF) control of focusing.

TV-AF is meant: also monitor and be somebody's turn to do the position of the variation of mobile relevant AF evaluation value signal with the focusing lens 104 of detection AF evaluation value signal maximum by mobile focusing lens 104, focus and control to reach focus state.

The general luminance signal component extraction high fdrequency component of passing through the band pass filter of special frequency band from vision signal is used as the AF evaluation value signal with this high fdrequency component.When with focusing lens 104 when proximal most position is shifted to infinity with the image of the subject of taking specified distance, high fdrequency component changes as shown in Figure 7.In Fig. 7, the position of the focusing lens 104 of AF evaluation value signal maximum is corresponding to the focal position (focus point) of this subject.

In Fig. 1, Reference numeral 141 illustrates outside distance measuring sensor unit, and it is as second detector, and to AF control circuit 131 provide with the corresponding subject range information of subject distance as second information.In response to the subject range information that is provided, AF control circuit 131 calculates the position that reaches the focusing lens 104 of focus state at this subject distance, and focusing lens 104 is moved to this focal position.Carry out outside range finding AF by this way.

Calculating in the AF control circuit 131 not only comprises the calculating of using formula, also comprise reading pre-stored in unshowned memory about data at the focal position of subject distance.

Then, to how utilizing outside distance measuring sensor unit 141 to detect the subject distance describe.There is several different methods to be used for range finding (range measurement).Fig. 9 and 10 illustrates the principle as the range measurement of the passive method of a kind of phase difference in these methods (phase difference passivemethod).

In embodiment 1, use outside distance measuring sensor unit 141 as the distance measuring sensor that is used for so-called passive AF method.With image pickup optical system outside distance measuring sensor unit 141 is set independently.In other words, outside distance measuring sensor unit 141 receives from subject and propagates and the luminous flux by image pickup optical system not.

Fig. 9 illustrates the example of structure of outside distance measuring sensor unit 141.In Fig. 9, Reference numeral 301 illustrates subject, and 331 illustrate first image forms lens, and 341 illustrate the first light receiving element array (line sensor), and 332 illustrate second image forms lens, and 342 illustrate the second light receiving element array (line sensor).Form in first and second line sensors 341 and 342 each by by rows a plurality of light receiving elements (pixel).Place first and second line sensors 341 and 342 and make the length of base of being separated by (base length) B therebetween.

A part of light from subject 301 forms lens 331 by first image, forms image on first line sensor 341.A part of light from subject 301 forms lens 332 by second image, forms image on second line sensor 342.

Line sensor 341 and 342 pairs of two subject images that form on these two line sensors carry out opto-electronic conversion.On line storage (line memory) 351 and 352, accumulate the signal of reading from line sensor 341 and 342 (picture signal) respectively.Figure 10 illustrate from line sensor 341 read in the picture signal 451 of line storage 351 accumulation and the picture signal 452 in line storage 352 accumulation of reading from another line sensor 342.

Then, with respectively on line storage 351 and 352 two picture signals 451 of accumulation and 452 be input to correlation calculations circuit 361.The irrelevant value that correlation calculations circuit 361 calculates between these two picture signals.

Particularly, correlation calculations circuit 361 at first compares the light quantity (brightness of the light that receives) of each pixel in the line sensor 341 and the light quantity of the related pixel in the line sensor 342, determine poor between it at each pixel, the addition pixel between the light quantity difference so that irrelevant value to be provided.

Then, the pixel of pixel centering that will determine the light quantity difference along the direction of laying out pixel is calculated light quantity difference and irrelevant value as mentioned above with respect to another kind of pixel shift and this corresponding side-play amount of pixel.By this way, order is shifted and this corresponding side-play amount of pixel with respect to one other pixel along the pixel of identical direction with pixel centering, and irrelevant value is calculated in each displacement.In addition, order with respect to the one other pixel of pixel centering this pixel that is shifted, is calculated irrelevant value to each displacement along opposite direction.

As the result of aforementioned calculation, the shift amount that will have maximum related value is defined as the pixel shift amount with minimum irrelevant value, that is, and and the right pixel shift amount of pixel that a plurality of pixel centerings of mutual comparison brightness amount have the minimum brightness difference.Particularly, in Figure 10, when checking correlation between picture signal 451 and 452, the shift amount X with maximum related value is corresponding to the distance X between the pixel that compares 441 and 442 with minimum irrelevant value.Can calculate shift amount with (quantity * pixel size of shifted pixels).

Then, subject distance calculation circuit 362 uses the principle of triangulation to be determined to the distance L of subject based on the pixel shift amount.

Formula (1) below utilizing calculates the subject distance L:

L＝Bf/X (1)

Wherein, X remarked pixel shift amount (with reference to Figure 10), B is the length of base, f is the focal length that image forms lens 331 and 332.

Though in embodiment 1, use the passive ranging method, can use other distance-finding method.For example, can use emission infrared ray, use triangulation to determine the active distance-finding method of subject distance.Alternatively, outside range cells can be exported above-mentioned pixel shift amount X (second information), and microcomputer uses this pixel shift amount X to determine the subject distance based on X subsequently.

In Fig. 1, Reference numeral 132 illustrates the horizontal decision circuitry that is arranged in the microcomputer 130, and horizontal decision circuitry is judged the level (hereinafter referred to as the light-receiving luminance level) of luminance component of the picture signals of line sensor 341 from outside distance measuring sensor unit 141 and 342 outputs.Particularly, horizontal decision circuitry 132 judges whether the light-receiving luminance level of line sensor 341 and 342 is higher than predetermined luminance level (first value).Horizontal decision circuitry 132 sends to AF control circuit 131 with the result.

Then, the AF control of in embodiment 1, being undertaken with reference to the flowchart text among the figure 2 by the microcomputer 130 that comprises AF control circuit 131.Carry out AF control according to the computer program that is stored in the microcomputer 130.This is applicable to the embodiment 2～8 that illustrates later.

In step (being designated hereinafter simply as S) 300, microcomputer 130 beginning AF controls.For example, the image that is used for producing a visual field read the image pickup signal readout interval from imaging apparatus 111, carry out the processing shown in this flow chart.

At S301, microcomputer 130 judges whether to have reached focus state.Reached focus state if be judged as, then flow process enters S308, otherwise, do not reach focus state if be judged as, then enter S302.Can judge the judgement of carrying out focus state by the focusing in the TV-AF operation that illustrates later.

At S302, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S308, otherwise, if do not focus operation, then enter S303.

At S303, microcomputer 130 carries out the TV-AF operation shown in the flow chart of Fig. 8.

With reference to figure 8, microcomputer 130 begins focusing at S1001 to be handled.At S1002, microcomputer 130 obtains the AF evaluation value signal from focus signal treatment circuit 121.

At S1003, check to focus on sign.Defocus (out-of-focus) state if removed the focusing sign with expression, then flow process enters S1004, otherwise, focus on sign with the expression focus state if be provided with, then enter S1010.

At S1004, judge whether to be judged as focus state.When the S1006 and the S1007 of explanation in the back replace mobile focusing lens 104 pre-determined numbers or more for a long time along opposite direction, be judged as focus state.If be judged as focus state, then flow process enters S1008, otherwise, if be not judged as focus state, then enter S1005.

At S1005, judge whether the moving direction of focusing lens 104 is correct.For example, when the AF evaluation of estimate of obtaining in current routine was higher than the AF evaluation of estimate of obtaining in last routine, the moving direction of focusing lens 104 was towards focal position, and it is correct therefore to be judged as moving direction, and flow process enters S1007.On the other hand, when the AF evaluation of estimate of obtaining in current routine was lower than the AF evaluation of estimate of obtaining in last routine, the moving direction of focusing lens 104 was opposite with focal position, thereby it is incorrect to be judged as moving direction, and flow process enters S1006.

At S1006, make the moving direction of focusing lens 104 opposite.

At S1007, further move focusing lens 104 along equidirectional.

At S1008, be judged as and reached focus state, stop focusing lens 104 to keep focus state.

At S1009, be provided with and focus on sign, the AF evaluation of estimate of focus state is stored in the unshowned memory.

At S1010, judge whether the AF evaluation of estimate that S1009 stored in last routine differs predetermined value or more with the AF evaluation of estimate of obtaining in current routine.If the AF evaluation of estimate of obtaining in current routine is lower than the AF evaluation of estimate predetermined value of storage or more, then be judged as and do not keep focus state, flow process enters S1011.If the AF evaluation of estimate of obtaining in current routine is lower than the AF evaluation of estimate of storage, both differences then are judged as the maintenance focus state less than predetermined value, and flow process enters S1012.

At S1011, remove and focus on sign.

At S1012, the AF evaluation of estimate that will obtain in current routine is stored in the unshowned memory, replaces the AF evaluation of estimate of being stored in last routine.

At S1013, finish the TV-AF operation.

S304 in Fig. 2, microcomputer 130 use the subject range information that is provided by outside distance measuring sensor unit 141 to calculate the position (hereinafter referred to as outside range finding focal position) that can reach the focusing lens 104 of focus state at this subject distance.The current location of relatively outside range finding focal position of microcomputer 130 and focusing lens 104, whether the current location of judging focusing lens 104 is away from outside range finding focal position.In the time of outside focusing lens 104 is positioned at the preset range that comprises outside range finding focal position, flow process enters S305.When focusing lens 104 was positioned at the preset range that comprises outside range finding focal position, flow process entered S308.

At S305, the light-receiving luminance level in the line sensor 341 and 342 of the outside distance measuring sensor of microcomputer 130 judgements unit 141 is higher than or is lower than predetermined luminance level (first value).In embodiment 1, the light-receiving luminance level of judging each line sensor in a pair of line sensor 341 and 342 is higher than or is lower than predeterminated level.Alternatively, can judge that the value calculated by the light-receiving luminance level in a pair of line sensor 341 of addition and 342 (promptly and) is higher than or is lower than predeterminated level.When being judged as the light-receiving luminance level when being higher than predeterminated level, flow process enters S306, otherwise, when being judged as the light-receiving luminance level when being lower than predeterminated level, enter S308.

At S306, microcomputer 130 judges that the correct moving direction (focus direction) of the focusing lens 104 whether outside range finding focal positions are judged with (S1005 among Fig. 8) during TV-AF at S303 handles with respect to the direction of the current location of focusing lens 104 is identical.If they are identical, it is correct then being judged as outside range finding focal position (or subject range information), and flow process enters S307, otherwise, if they are inequality, then enter S308.

At S307, microcomputer 130 moves to outside range finding focal position with focusing lens 104.In other words, carry out outside range finding AF.

At S308, microcomputer 130 finishes the processing of AF control.

As mentioned above, in embodiment 1, be higher than or be lower than the outside range finding AF that the predetermined luminance level judges whether to utilize the subject range information that is provided by outside distance measuring sensor unit 141 according to the light-receiving luminance level in the outside distance measuring sensor unit 141.If the light-receiving luminance level is lower, then carry out TV-AF.Therefore, when having user's barriers such as hand on the light path between distance measuring sensor unit 141 and the subject externally, can prevent to carry out outside range finding AF, simultaneously, utilize TV-AF can reach correct focus state based on incorrect subject range information.

In addition, according to embodiment 1, be higher or hang down and judge whether carry out outside range finding AF according to the light-receiving luminance level of a pair of line sensor 341 and 342 among both, therefore, even when two light paths of 341 and 342 from the subject to the line sensor are blocked, also can obtain above-mentioned effect.

Embodiment 2

Fig. 3 illustrates the structure as the video camera of embodiments of the invention 2.In embodiment 2, use with embodiment 1 in identical Reference numeral represent with embodiment 1 in identical parts.

In embodiment 1, be higher or hang down and judge whether carry out outside range finding AF according to light-receiving luminance level in the distance measuring sensor unit 141 externally.In embodiment 2, judge whether carry out outside range finding AF according to level from the correlation of the output of a pair of line sensor 341 and 342.

The calculating of the correlation (irrelevant value) in the outside distance measuring sensor unit 141 and the calculating of subject distance are as illustrated at embodiment 1.Particularly, then will be that read and be accumulated in the correlation calculations circuit 361 that two picture signals on line storage 351 and 352 are input to the irrelevant value of calculating these two picture signals subsequently from line sensor shown in Figure 9 341 and 342.Subject distance calculation circuit 362 calculates the subject distance based on the shift amount between the pixel that has minimum irrelevant value (maximum related value) the pixel on the line sensor of finding from the comparison of light quantity 341 and 342.

In Fig. 3, Reference numeral 133 illustrates the correlation decision circuitry, and it is judged from the level of the correlation of these two picture signals that line sensor 341 and 342 is read.

With reference to Figure 11 correlation is described.In Figure 11, picture signal on the line storage 351 is read and be accumulated in to Reference numeral 451 ' illustrate from line sensor 341, and picture signal on the line storage 352 is read and be accumulated in to Reference numeral 452 ' illustrate from another line sensor 342.Figure 11 displacement shift amount X is shown so that its have the picture signal 451 of maximum related value ' and 452 '.

Reference numeral 454 and 455 is illustrated in the maximum shift amount when determining correlation in the pre-determined relevancy comparison domain.Generally can the maximum shift amount be set to half or bigger corresponding shift amount with the length of line sensor, so that the correlation of high accuracy to be provided.

Dash area 453 is corresponding to the irrelevant value of two illustrated among the embodiment 1 picture signals.Because irrelevant value 453 is less, promptly correlation is bigger, thereby can correctly determine the subject distance.Whether correlation decision circuitry 133 judges correlation greater than predetermined value, and judged result is sent to AF control circuit 131 in the microcomputer 130.

Then, comprise the AF control that the microcomputer 130 of AF control circuit 131 is carried out with reference to the flowchart text among the figure 4.

At S400, microcomputer 130 beginning AF controls.For example, carry out the processing shown in this flow chart at the readout interval of reading image pickup signal from the imaging apparatus 111 of the image that is used for producing a visual field.

At S401, microcomputer 130 judges whether to have reached focus state.Reached focus state if be judged as, then flow process enters S408, otherwise, do not reach focus state if be judged as, then enter S403.Can judge by the focusing in the TV-AF operation of explanation after a while and carry out the judgement of focus state.

At S402, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S408, otherwise, if focus operation, then enter S403.

At S403, microcomputer 130 carries out the TV-AF operation shown in the flow chart of Fig. 8.

At S404, microcomputer 130 uses the subject range information that is provided by outside distance measuring sensor unit 141 to calculate the outside range finding focal position that can reach the focusing lens 104 of focus state at this subject distance.The current location of relatively outside range finding focal position of microcomputer 130 and focusing lens 104, whether the current location of judging focusing lens 104 is away from outside range finding focal position.In the time of outside focusing lens 104 is positioned at the preset range that comprises outside range finding focal position, flow process enters S405.When focusing lens 104 was positioned at the preset range that comprises outside range finding focal position, flow process entered S408.

At S405, microcomputer 130 judge the correlation of the picture signal on the line sensor 341 and 342 that outside distance measuring sensor unit 141 provides be greater than or less than predetermined value (first value).When being judged as correlation greater than predetermined value, flow process enters S406, otherwise, when being judged as correlation, enter S408 less than predetermined value.

At S406, microcomputer 130 judges that the correct moving direction of the focusing lens 104 whether outside range finding focal positions are judged with (S1005 among Fig. 8) during TV-AF at S403 handles with respect to the direction of the current location of focusing lens 104 is identical.If they are identical, it is correct then being judged as outside range finding focal position (or subject range information), and flow process enters S407, otherwise, if they are inequality, then enter S408.

At S407, microcomputer 130 moves to outside range finding focal position with focusing lens 104.In other words, carry out outside range finding AF.

At S408, microcomputer 130 finishes the processing of AF control.

As mentioned above, in embodiment 2, according to the correlation of the picture signal that provides by outside distance measuring sensor unit 141 be greater than or judge whether utilize the outside range finding AF of the subject range information that provides by outside distance measuring sensor unit 141 less than predetermined value.If correlation is less, then carry out TV-AF.Therefore, when having user's barriers such as hand on the light path between distance measuring sensor unit 141 and the subject externally, can prevent to carry out outside range finding AF, simultaneously, can utilize TV-AF to reach correct focus state based on incorrect subject range information.

Embodiment 3

Fig. 5 illustrates the structure as the video camera of embodiments of the invention 3.In embodiment 3, utilize with embodiment 1 in identical Reference numeral represent with embodiment 1 in identical parts.

The calculating of the subject distance among the embodiment 3 in the outside distance measuring sensor unit 141 is as illustrated among the embodiment 1.Particularly, will read and be accumulated in the correlation calculations circuit 361 that two picture signals on line storage 351 and 352 are input to the irrelevant value of calculating these two picture signals subsequently from line sensor shown in Figure 9 341 and 342 then.Subject distance calculation circuit 362 calculates the subject distance based on the shift amount between the pixel that has minimum irrelevant value (maximum related value) the pixel on the line sensor of finding from the comparison of light quantity 341 and 342.

In Fig. 5, Reference numeral 134 illustrates apart from decision circuitry 134, and it judges that the subject distance that is provided by outside distance measuring sensor unit 141 is short still longer than preset distance (first distance: for example, several centimetres).Apart from decision circuitry 134 judged result is sent to AF control circuit 131 in the microcomputer 130.

Then, the AF control of being undertaken by the microcomputer 130 that comprises AF control circuit 131 with reference to the flowchart text among the figure 6.

At S500, microcomputer 130 beginning AF controls.For example, carry out the processing shown in this flow chart at the readout interval of reading image pickup signal from the imaging apparatus 111 of the image that is used for producing a visual field.

At S501, microcomputer 130 judges whether to have reached focus state.Can judge the judgement of carrying out focus state by the focusing in the TV-AF operation of explanation after a while.Reached focus state if be judged as, then flow process enters S508, otherwise, do not reach focus state if be judged as, then enter S503.

At S502, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S508, otherwise, if focus operation, then enter S503.

At S503, microcomputer 130 carries out the TV-AF operation shown in the flow chart of Fig. 8.

At S504, the subject range information that is provided by outside distance measuring sensor unit 141 is provided microcomputer 130, to calculate the outside range finding focal position that can reach the focusing lens 104 of focus state at this subject distance.The current location of relatively outside range finding focal position of microcomputer 130 and focusing lens 104, whether the current location of judging focusing lens 104 is away from outside range finding focal position.In the time of outside focusing lens 104 is positioned at the preset range that comprises outside range finding focal position, flow process enters S505.When focusing lens 104 was positioned at the preset range that comprises outside range finding focal position, flow process entered S508.

At S505, microcomputer 130 judges that the subject distance that is provided by outside distance measuring sensor unit 141 is than preset distance nearly (weak point) (length) still far away.When being judged as the subject distance than preset distance length, flow process enters S506, otherwise, when being judged as the subject distance in short-term, enter S508 than preset distance.

At S509, microcomputer 130 judges whether at S505 be that the subject distance judgement shorter than preset distance that is provided by outside distance measuring sensor unit 141 has been provided for the first time.In other words, microcomputer 130 judges whether be judged as subject apart from longer than preset distance in last routine.Because only, just limit outer side AF, thereby carry out this judgement when in two continuous routines, being judged as the subject distance continuously in short-term than preset distance.When S505 makes this judgement for the first time, flow process enters S506, otherwise, when for the second time or when continuing to make this judgement, entering S508 at S505.

At S506, microcomputer 130 judges that the correct moving direction of the focusing lens 104 whether outside range finding focal positions are judged with (S1005 among Fig. 8) during TV-AF at S503 handles with respect to the direction of the current location of focusing lens 104 is identical.If they are identical, it is correct then being judged as outside range finding focal position (or subject range information), and flow process enters S507, otherwise, if they are inequality, then enter S508.

At S507, microcomputer 130 moves to outside range finding focal position with focusing lens 104.In other words, carry out outside range finding AF.

At S508, microcomputer 130 finishes the processing of AF control.

As mentioned above, in embodiment 3, the subject distance that provides according to outside distance measuring sensor unit 141 is than preset distance length or the short outside range finding AF that judges whether utilize the subject range information.If the subject distance is shorter, then carry out TV-AF.Therefore, when having user's barriers such as hand on the light path between distance measuring sensor unit 141 and the subject externally, can prevent based on carrying out outside range finding AF as the subject range information about information to the distance of this barrier, simultaneously, can utilize TV-AF to reach correct focus state.

Even when being judged as the subject distance more in short-term, use the subject range information that provides by outside distance measuring sensor unit 141 to carry out once outside range finding AF.This can focus fast to the subject of closely locating.

According to embodiment 1～3, light-receiving luminance level or correlation in second detector are low, when representing that detected second information of second detector may be incorrect, utilize the first information control of focusing, and do not utilize the control of focusing of second information.Therefore, can prevent to reach correct focus state based on the control of focusing of incorrect second information.

Embodiment 4

Figure 12 illustrates the structure as the video camera of embodiments of the invention 4 (picture pick-up device).In Figure 12, use with embodiment 1～3 in identical Reference numeral represent with embodiment 1～3 in identical parts.

Reference numeral 204 illustrates and shows circuit is set, and it is illustrated in the character display signal that shows characters such as the literal prepared in the memory (not shown) of circuit 204 and figure are set to supercircuit 205 outputs.In this case, display video (photographic images) and character on monitor 202.

Reference numeral 136 illustrates horizontal transformation period decision circuitry, and whether its level (hereinafter referred to as the light-receiving luminance level) of luminance component of judging the picture signals of line sensor 341 from outside distance measuring sensor unit 141 and 342 outputs is lower than predetermined luminance level (first value).Horizontal transformation period decision circuitry 136 judges that also the light-receiving luminance level is lower than the predetermined luminance horizontal state and whether has continued predetermined amount of time (very first time section) or longer.

In advance predetermined luminance level and predetermined amount of time are stored in the unshowned memory of microcomputer 130.Horizontal transformation period decision circuitry 136 sends to AF control circuit 131 in the microcomputer 130 with judged result.

Then, with reference to the AF control of being undertaken by the microcomputer 130 that comprises AF control circuit 131 among the flowchart text embodiment 4 among Figure 13.

At S700, microcomputer 130 beginning AF controls.For example, carry out the processing shown in this flow chart at the readout interval of reading image pickup signal from the imaging apparatus 111 of the image that is used for producing a visual field.

At S701, microcomputer 130 judges whether to have reached focus state.Reached focus state if be judged as, then handled entering S708, otherwise, do not reach focus state if be judged as, then enter S702.Can judge by the focusing in the TV-AF operation and carry out the judgement of focus state.

At S702, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S708, otherwise, if focus operation, then enter S703.

At S703, the TV-AF operation shown in the flow chart that microcomputer 130 carries out among Fig. 8.

At S704, microcomputer 130 uses the subject range information that is provided by outside distance measuring sensor unit 141 to calculate the position (hereinafter referred to as outside range finding focal position) that can reach the focusing lens 104 of focus state at this subject distance.Microcomputer 130 should the outside range finding focal position compare with current location by the detected focusing lens 104 of unshowned lens position detector, whether the current location of judging focusing lens 104 away from this outside focal position of finding range.In the time of outside focusing lens 104 is positioned at the preset range that comprises this outside range finding focal position, flow process enters S705.When focusing lens 104 was positioned at the preset range that comprises this outside range finding focal position, flow process entered S708.

At S705, microcomputer 130 judges whether the light-receiving luminance level in the line sensor 341 and 342 of outside distance measuring sensor unit 141 is lower than predetermined luminance level (first value).In embodiment 4, judge whether the light-receiving luminance level of each line sensor in a pair of line sensor 341 and 342 is lower than the predetermined luminance level.Alternatively, can judge by this value that light-receiving luminance level in line sensor 341 and 342 is calculated of addition (promptly and) whether be lower than predeterminated level.

In addition, at S705, when being judged as the light-receiving luminance level when being lower than the predetermined luminance level, microcomputer 130 judges that the light-receiving luminance level is lower than the predetermined luminance horizontal state and whether has continued predetermined amount of time or longer.If this state continuance predetermined amount of time or longer, then flow process enters S709, otherwise, then enter S706.

At S706, microcomputer 130 judges that the correct moving direction of the focusing lens of whether being judged with (S1005 among Fig. 8) TV-AF at step S703 handles from the direction of the outside range finding focal position that the subject range information that is provided by outside distance measuring sensor unit 141 is calculated 104 is identical.If they are identical, then to be judged as the subject distance detection result of outside distance measuring sensor be correct to microcomputer 130, and flow process enters S707, otherwise, if they are inequality, then enter S708.

At S707, microcomputer 130 moves to outside range finding focal position with focusing lens 104.In other words, carry out outside range finding AF.

At S709, microcomputer 130 makes and shows that circuit 204 is set utilizes the literal that for example " does not use the information from distance measuring sensor " or figure character display on monitor 202 of representing this situation.

At S708, microcomputer 130 finishes the processing of AF control.

The variation of the light-receiving luminance level in the outside distance measuring sensor unit 141 then, is described with reference to Figure 16.

In Figure 16, Reference numeral 481 illustrates light-receiving luminance level in the outside distance measuring sensor unit 141 along with the example of the variation of time.Light-receiving luminance level 481 (being represented by vertical axis) is because the moving of subject, camera rocks etc. along with the time of being represented by trunnion axis changes.

Among Figure 16 as " a ", " b ", " c ", " d ", " e " and " f " ... shown in each luminance level represent the variable quantity of the brightness of time per unit.For example, can provide the brightness variable quantity of time per unit by poor between previous sampled value and the current sampled value sampled, obtained to the light-receiving luminance level in outside distance measuring sensor unit 141 (line sensor 341 and 342) with the readout interval of image pickup signal.

In Figure 16, the time " P " of brightness when user's barriers such as hand cover the front of outside distance measuring sensor unit 141 changes.The barrier that covers outside distance measuring sensor unit 141 stops that the light from subject enters outside distance measuring sensor unit 141, causes the light-receiving luminance level to drop sharply to below the predetermined luminance level " L1 ".After the light-receiving luminance level drops to below the predetermined luminance level " L1 ", shown in " x ", almost do not change.

Sampling time after being right after below the light-receiving luminance level drops to the horizontal L1 of predetermined luminance is expressed as " t1 ".If the light-receiving luminance level remained on below the predeterminated level L1 through predetermined amount of time " T " sampling time " t2 " afterwards since the time " t1 ", then the S705 of flow process from Figure 13 enters S709.

If having removed the barrier that covers outside distance measuring sensor unit 141 before through predetermined amount of time " T ", the light-receiving luminance level is got back to more than the predetermined luminance level " L1 ", then flow process enters S706.

For example, the required maximum time period of focusing control based on reach focus state after defocus condition when covering outside distance measuring sensor unit 141 without any barrier suitably is provided with predetermined amount of time T.

As mentioned above, in embodiment 4, be lower than the predetermined luminance horizontal state according to the light-receiving luminance level in the outside distance measuring sensor unit 141 and whether continued predetermined amount of time or longer, judge whether utilize the outside range finding AF of the subject range information that provides by outside distance measuring sensor unit 141.If this state continuance predetermined amount of time or longer, then carry out TV-AF.Therefore, when having user's barriers such as hand on the light path between distance measuring sensor unit 141 and the subject externally, can prevent to carry out outside range finding AF, simultaneously, can utilize TV-AF to reach correct focus state based on incorrect subject range information.

In addition, according to embodiment 4, judge whether carry out outside range finding AF according to the light-receiving luminance level of a pair of line sensor 341 and 342 among both, thereby even when two light paths of 341 and 342 from the subject to the line sensor are blocked, also can obtain above-mentioned effect.

Embodiment 5

Figure 14 illustrates the structure as the video camera of embodiments of the invention 5.In embodiment 5, use with embodiment 1～4 in identical Reference numeral represent with embodiment 1～4 in identical parts.

In embodiment 4, judge whether carry out outside range finding AF based on the light-receiving luminance level in the outside distance measuring sensor unit 141.On the contrary, in embodiment 5, judge whether carry out outside range finding AF based on correlation from the output of a pair of line sensor 341 and 342.

The calculating of the correlation (irrelevant value) in the outside distance measuring sensor unit 141 and the calculating of subject distance are as illustrated at embodiment 1 and 2.Particularly, will read and be accumulated in the correlation calculations circuit 361 that two picture signals on line storage 351 and 352 are input to the irrelevant value of calculating these two picture signals subsequently from line sensor shown in Figure 9 341 and 342 then.Subject distance calculation circuit 362 calculates the subject distance based on the shift amount between the pixel that has minimum irrelevant value (the highest correlation) the pixel on the line sensor of finding from the comparison of light quantity 341 and 342.

In Figure 14, Reference numeral 137 illustrates correlation transformation period decision circuitry, and whether its judgement is lower than predetermined value (first value) from the correlation of two picture signals that a pair of line sensor 341 and 342 is read.

Correlation transformation period decision circuitry 137 judges also whether the state that correlation is lower than predetermined value has continued predetermined amount of time (very first time section) or longer.In advance this predetermined value and predetermined amount of time are stored in the microcomputer 130 in the unshowned memory.Correlation transformation period decision circuitry 137 sends to AF control circuit 131 in the microcomputer 130 with judged result.

Correlation is as illustrated with reference to Figure 11 in embodiment 2.

Then, the AF control of being undertaken by the microcomputer 130 that comprises AF control circuit 131 with reference to the flowchart text among Figure 15.

At S1400, microcomputer 130 beginning AF controls.For example, carry out the processing shown in this flow chart at the readout interval of reading image pickup signal from the imaging apparatus 111 of the image that is used for producing a visual field.

At S1401, microcomputer 130 judges whether to have reached focus state.Reached focus state if be judged as, then flow process enters S1408, otherwise, do not reach focus state if be judged as, then enter S1402.Can judge by the focusing in the TV-AF operation and carry out the judgement of focus state.

At S1402, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S1408, otherwise, if focus operation, then enter S1403.

At S1403, microcomputer 130 carries out the TV-AF operation shown in the flow chart of Fig. 8.

At S1404, microcomputer 130 uses the subject range information that is provided by outside distance measuring sensor unit 141 to calculate the outside range finding focal position that can reach the focusing lens 104 of focus state at this subject distance.The current location of relatively outside range finding focal position of microcomputer 130 and focusing lens 104, whether the current location of judging focusing lens 104 is away from outside range finding focal position.In the time of outside focusing lens 104 is positioned at the preset range that comprises outside range finding focal position, flow process enters S1405.When focusing lens 104 was positioned at the preset range that comprises outside range finding focal position, flow process entered S1408.

At S1405, microcomputer 130 judges whether the correlation of the picture signal in the line sensor 341 and 342 that outside distance measuring sensor unit 141 provides is lower than predetermined value.

In addition, when being judged as this correlation at S1405 when being lower than predetermined value, microcomputer 130 judges whether the state that correlation is lower than predetermined value has continued predetermined amount of time or longer.If this state continuance predetermined amount of time or longer, then flow process enters S1408, otherwise, enter S1406.

At S1406, microcomputer 130 judges that the correct moving direction of the focusing lens 104 whether outside range finding focal positions are judged with (S1005 among Fig. 8) during TV-AF at S1403 handles with respect to the direction of focusing lens 104 is identical.If they are identical, then to be judged as this outside range finding focal position (or subject range information) be correct to microcomputer 130, and flow process enters S1407, otherwise, if they are inequality, then enter S1408.

At S1407, microcomputer 130 moves to outside range finding focal position with focusing lens 104.In other words, carry out outside range finding AF.

At S1408, microcomputer 130 finishes the processing of AF control.

As mentioned above, in embodiment 5, whether the state that the correlation of the picture signal that provides according to outside distance measuring sensor unit 141 is lower than predetermined value has continued predetermined amount of time or longer, judges whether to utilize the outside range finding AF of the subject range information that outside distance measuring sensor unit 141 provides.If this state continuance predetermined amount of time or longer, then carry out TV-AF.Therefore, when having user's barriers such as hand on the light path between distance measuring sensor unit 141 and the subject externally, can prevent to carry out outside range finding AF, simultaneously, can utilize TV-AF to reach correct focus state based on incorrect subject range information.

According to embodiment 4 and 5, low light-receiving luminance level in second detector or low correlation state continuance predetermined amount of time or longer, when representing that second information may be incorrect, utilize the first information control of focusing, and do not utilize the control of focusing of second information.Therefore, can prevent based on the control of focusing of incorrect second information, and can reach correct focus state.

Embodiment 6

Figure 17 illustrates the structure as the video camera of embodiments of the invention 6 (picture pick-up device).In Figure 17, use with embodiment 1～5 in identical Reference numeral represent with embodiment 1～5 in identical parts.

In Figure 17, luminance signal testing circuit 181 detects luminance component included from the luminance signal component of the vision signal of camera signal treatment circuit 112 outputs and it is carried out integration.Its result is input to AE control circuit 191 in the microcomputer 130.

Automatic exposure (AE) operation then is described.The predetermined luminance level (predetermined exposure level) of expression correct exposure compares in detected luminance signal that luminance signal testing circuit 181 is provided and the AE control circuit 191.AE control circuit 191 provides the aperture control signal of the difference between detected luminance signal of expression and the predetermined exposure level to the aperture drive circuit 126 that drives aperture 103 subsequently according to the aperture control signal.This has changed the diameter of the aperture that is formed by a plurality of aperture blades (not shown) in the aperture 103, the light quantity that enters imaging apparatus 111 with adjusting.

When the luminance level of detected luminance signal is higher than the predetermined exposure level, that is to say that when subject brightness was high, 191 outputs of AE control circuit were used to drive the aperture control signal of aperture 103 with the stop down diameter.This minimizing enters the light quantity of imaging apparatus 111.Another kind of aspect when the luminance level of detected luminance signal is lower than the predetermined exposure level, that is to say, when subject brightness was low, 191 outputs of AE control circuit were used to drive the aperture control signal of aperture 103 to increase diaphragm diameter.This increase enters the light quantity of imaging apparatus 111.

When the luminance level of detected luminance signal reaches the predetermined exposure level (in fact, in the time of in the luminance level of detected luminance signal drops on based on the particular range of predetermined exposure level), utilize the stable control to aperture 103 of this diaphragm diameter to keep correct exposure.

Also the aperture control signal that AE control circuit 191 is provided is input to AE variation decision circuitry 192.AE changes decision circuitry 192 and judges that whether the aperture control signal of input has changed scheduled volume or more, outputs to AF control circuit 131 with judged result.This scheduled volume is set to the corresponding value of aperture shelves (aperture step) with right quantity, to prevent frequently switching between TV-AF and outside range finding AF.AF control circuit 131 also changes decision circuitry 192 by AE and detects the diaphragm diameter of being represented by the aperture control signal (f-number).

AF control circuit 131 switches between TV-AF and outside range finding AF according to the judged result that changes decision circuitry 192 from AE and this f-number.AF control circuit 131 and AE change decision circuitry 192 and constitute the focusing controller.

AF control circuit 131 also has the function of detection from the level (about the information of light-receiving state, hereinafter referred to as the light-receiving luminance level) of the luminance component of the picture signals of the line sensor 341 of outside distance measuring sensor unit 141 and 342 outputs.

Then, comprise the AF control that the microcomputer 130 of AF control circuit 131 is carried out with reference to the flowchart text among Figure 18.

The main-process stream of AF control at first is described with reference to Figure 18.

At S800, microcomputer 130 beginning AF controls.For example, carry out the processing shown in this flow chart at the readout interval of reading image pickup signal from the imaging apparatus 111 of the image that is used for producing a visual field.

At S801, microcomputer 130 judges whether to have reached focus state.Reached focus state if be judged as, then flow process enters S808, otherwise, do not reach focus state if be judged as, then enter S802.Can judge by the focusing in the TV-AF operation and carry out the judgement of focus state.

At S802, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S808, otherwise, if focus operation, then enter S803.

At S803, microcomputer 130 carries out the TV-AF operation shown in the flow chart of Fig. 8.

At S804, microcomputer 130 uses the subject range information that is provided by outside distance measuring sensor unit 141 to calculate the position (hereinafter referred to as outside range finding focal position) that can reach the focusing lens 104 of focus state at this subject distance.Microcomputer 130 should the outside range finding focal position compare with current location by the detected focusing lens 104 of unshowned lens position detector, whether the current location of judging focusing lens 104 away from the outside focal position of finding range.In the time of outside focusing lens 104 is positioned at the preset range that comprises outside range finding focal position, flow process enters S805.When focusing lens 104 was positioned at the preset range that comprises outside range finding focal position, flow process entered S808.

At S805, microcomputer 130 judges from the judged result of AE variation decision circuitry 192 whether represent that the aperture control signal has changed scheduled volume or more (that is to say whether the state of a control of aperture 103 changes).Microcomputer 130 judges that also whether the f-number of being represented by the aperture control signal is corresponding to predetermined diaphragm diameter or littler.When the aperture control signal has changed scheduled volume or more for a long time, perhaps represent predetermined diaphragm diameter or more hour, flow process enters S809 when the aperture control signal, otherwise, enter S808.

Predetermined diaphragm diameter for example is meant the diaphragm diameter less than full diaphragm diameter.Predetermined diaphragm diameter can be full diaphragm diameter.In this case, when aperture 103 is opened fully, and output is when being used to increase the aperture control signal of diameter of aperture 103, and the aperture control signal does not represent to be equal to or less than the diaphragm diameter of predetermined diaphragm diameter, and flow process enters S808.Aperture 103 is controlled to be predetermined diaphragm diameter or littler, to realize correct exposure.

At S809, microcomputer 130 judges whether that the variation according to the aperture control signal changes the light-receiving luminance level in the outside distance measuring sensor unit 141.The variation of light-receiving luminance level then, is described with reference to Figure 19.

In Figure 19, dotted line is represented the example of the variation of aperture control signal (diaphragm diameter).On the other hand, solid line is represented the example of the variation of the light-receiving luminance level in the outside distance measuring sensor unit 141.From the time " t0 " to " t1 ", the light-receiving luminance level in the outside distance measuring sensor unit 141 is followed the variation of aperture control signal and is changed.This is illustrated in the subject that exists in the detection visual field of outside distance measuring sensor unit 141 by imaging apparatus 111 photographic images.

Yet, the time " t1 " afterwards, the light-receiving luminance level in the outside distance measuring sensor unit 141 drops to below " L1 ", and does not almost change.In other words, the light-receiving luminance level in the outside distance measuring sensor unit 141 does not change according to the variation of aperture control signal.This means in the time " t1 " has user's barriers such as hand to cover the front of outside distance measuring sensor unit 141.

When the variation of following the aperture control signal when the light-receiving luminance level in the outside distance measuring sensor unit 141 changes, be judged as the suitable light-receiving state that has reached the subject range information that is used to provide correct, flow process enters S806.When the light-receiving luminance level does not change according to the variation of aperture control signal, be judged as the suitable light-receiving state that does not reach the subject range information that is used to provide correct, flow process enters S810.

At S806, whether the direction that the focal position (hereinafter referred to as outside range finding focal position) that is calculated from the subject range information that is provided by outside distance measuring sensor unit 141 is provided for microcomputer 130 is identical with the correct moving direction that (S1005 among Fig. 8) TV-AF at S803 handles judged.If they are identical, then to be judged as the subject distance detection result of outside distance measuring sensor be correct to microcomputer 130, and flow process enters S807, otherwise, if they are inequality, then enter S808.

At S807, microcomputer 130 moves to outside range finding focal position with focusing lens 104.In other words, carry out outside range finding AF.

At S810, microcomputer 130 makes and shows that circuit 204 is set utilizes the literal that for example " does not use the information from range sensor " or figure character display on monitor 204 of representing this situation.

At S808, microcomputer 130 finishes the processing of AF control.

As mentioned above, in embodiment 6, detect the variation of existing subject in the detection visual field of outside distance measuring sensor unit 141 with reference to the state of a control of aperture 103.Do not change by detecting the light-receiving luminance level relevant, have barrier between the distance measuring sensor unit 141 and subject and be judged as externally according to the variation of subject with the light-receiving state of outside distance measuring sensor unit 141.In this case, outside range finding AF can be limited, the TV-AF control of focusing accurately can be utilized to avoid wrong focusing control.Consequently, can realize level and smooth focusing control.

At judge light-receiving luminance level in the outside distance measuring sensor unit 141 whether follow aperture 103 state of a control variation and situation about changing has illustrated embodiment 6.Yet, illustrated in embodiment 7 as the back, can judge the correlation that provides in the distance measuring sensor unit 141 externally whether follow aperture 103 state of a control variation and change.

Embodiment 7

Figure 20 illustrates the structure as the video camera of embodiments of the invention 7.In embodiment 7, use with embodiment 1～6 in identical Reference numeral represent with embodiment 1～6 in identical parts.

In embodiment 7,, judge whether limit outside range finding AF according to whether changing according to the variation of the state of a control of Automatic white balance (AWB, auto-white balance) about the information of the light-receiving state of outside distance measuring sensor unit 141.Use correlation that outside distance measuring sensor unit 141 provides as information about the light-receiving state of outside distance measuring sensor unit 141.

In Figure 20, Reference numeral 195 illustrates the white balance control circuit of the white balance (color balance) in the control camera signal treatment circuit 112.Particularly, the gain of each chrominance signal of white balance control circuit 195 control makes the summation performance white of from the vision signal of the camera signal treatment circuit 112 inputs chrominance signal of included R, G and B.

Reference numeral 196 illustrates the white balance that is arranged in the microcomputer 130 and changes decision circuitry.White balance changes decision circuitry 196 and judges whether the gain (that is to say the state of a control of white balance) of each chrominance signal of white balance control circuit 195 controls has changed scheduled volume or more.The corresponding value of gain ranging that this scheduled volume is set to and is suitable for preventing frequently switching between TV-AF and outside range finding AF.

The calculating of the correlation (irrelevant value) in the outside distance measuring sensor unit 141 and the calculating of subject distance are illustrated as embodiment 1 and 2.Particularly, will read and be accumulated in the correlation calculations circuit 361 that two picture signals on line storage 351 and 352 are input to the irrelevant value of calculating these two picture signals subsequently from line sensor shown in Figure 9 341 and 342.Calculate the subject distance based on the shift amount between the pixel that has minimum irrelevant value (the highest correlation) the pixel on the line sensor of finding from the comparison of light quantity 341 and 342.

Correlation is as illustrated with reference to Figure 11 in embodiment 2.

When having the subject of this video camera photographic images in the detection visual field of distance measuring sensor unit 141 externally, correlation (the highest correlation) changes according to the variation of the state of a control of white balance.

Yet when externally having barrier between distance measuring sensor unit 141 and the subject, correlation does not change according to the variation of the state of a control of white balance.In embodiment 7, use this situation to judge whether to exist barrier.

Then, the AF control of being undertaken by the microcomputer 130 that comprises AF control circuit 131 with reference to the flowchart text among Figure 21.

At S1200, microcomputer 130 beginning AF controls.For example, carry out the processing shown in this flow chart at the readout interval of reading image pickup signal from the imaging apparatus 111 of the image that is used for producing a visual field.

At S1220, microcomputer 130 makes white balance control circuit 195 carry out white balance control.

At S1201, microcomputer 130 judges whether to have reached focus state.Reached focus state if be judged as, then flow process enters S1208, otherwise, do not reach focus state if be judged as, then enter S1202.Can judge by the focusing in the TV-AF operation and carry out the judgement of focus state.

At S1202, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S1208, otherwise, if focus operation, then enter S1203.

At S1203, microcomputer 130 carries out the TV-AF operation shown in the flow chart of Fig. 8.

At S1204, the current location of focusing lens 140 and the focal position that is calculated based on the subject range information that is provided by outside distance measuring sensor unit 141 are provided microcomputer 130, judge that whether difference between them is greater than predetermined value.If be somebody's turn to do difference greater than predetermined value, then microcomputer 130 is judged as focusing lens 104 away from focal position, and flow process enters S1205.If this difference is equal to or less than predetermined value, then microcomputer 130 is judged as focusing lens 104 and is positioned at focal position, and flow process enters S1208.

At S1205, the judged result that microcomputer 130 uses white balance to change decision circuitry 196 judges whether the white balance state of a control change has taken place.If change has taken place the white balance state of a control, then flow process enters S1209, otherwise, if the white balance state of a control does not change, then enter S1208.

At S1209, microcomputer 130 judges whether correlation that outside distance measuring sensor unit 141 provides is followed the state of a control of white balance and changed.Corresponding relation between correlation and the white balance state of a control is similar to aperture control signal shown in Figure 19 and the corresponding relation between the light-receiving luminance level.

When variation has taken place in the variation of following the white balance state of a control when correlation, be judged as the suitable light-receiving state that has reached the subject range information that is used to provide correct in the distance measuring sensor unit 141 externally, flow process enters S1206.When correlation does not change according to the variation of white balance state of a control, be judged as the suitable light-receiving state that does not reach the subject range information that is used to provide correct in the distance measuring sensor unit 141 externally, flow process enters S1208.

At S1206, whether microcomputer 130 is judged from the direction of the outside range finding focal position that the subject range information that is provided by outside distance measuring sensor unit 141 is calculated identical with the correct moving direction that (S1005 among Fig. 8) TV-AF at S1203 handles judged.If they are identical, then to be judged as the subject distance detection result of outside distance measuring sensor be correct to microcomputer 130, and flow process enters S1207, otherwise, if their differences then enter S1208.

At S1207, microcomputer 130 moves to outside range finding focal position with focusing lens 104.This can utilize outside range finding AF to reach focus state or approximate focus state.

At S1208, microcomputer 130 finishes this flow process.

As mentioned above, in embodiment 7, the state of a control of reference white balance detects the variation of the subject that exists in the detection visual field of distance measuring sensor unit 141 externally.Do not change by detecting the correlation relevant, be judged as externally and have barrier between the distance measuring sensor unit 141 and subject according to the variation of subject with the light-receiving state of outside distance measuring sensor unit 141.In this case, outside range finding AF can be limited avoiding wrong focusing control, and the TV-AF control of focusing accurately can be utilized.Consequently, can realize level and smooth focusing control.

When the state of a control of white balance does not change, that is to say that when subject or subject image (video of shooting) when not changing, the outside range finding of restriction AF carries out TV-AF.Therefore, under the situation beyond the situation that has barrier as mentioned above, can carry out level and smooth focusing control.

At judge the correlation that provides in the distance measuring sensor unit 141 externally whether follow white balance state of a control variation and situation about changing has illustrated embodiment 7.Yet, as illustrated among the embodiment 6, can judge light-receiving luminance level in the outside distance measuring sensor unit 141 whether follow white balance state of a control variation and change.

Embodiment 8

Figure 22 illustrates the structure as the video camera of embodiments of the invention 8.In embodiment 8, use with embodiment 1～7 in identical Reference numeral represent with embodiment 1～7 in identical parts.

In embodiment 8, according to about the information of the light-receiving state of outside distance measuring sensor unit 141 whether according to for example since the camera movement that user's hand fine motion causes (promptly, camera rocks) detected state variation and change, judge whether limit outside range finding AF.In embodiment 7, use correlation that outside distance measuring sensor unit 141 provides as information about the light-receiving state of outside distance measuring sensor unit 141.

In Figure 22, Reference numeral 211 illustrates and detects the detecting sensor of rocking that camera rocks, and is formed by angular-rate sensor, angular acceleration transducer etc. and rocks detecting sensor.Can detect camera by the motion vector that calculates vision signal and rock, replace using and rock detecting sensor 211.

Reference numeral 105 illustrates image stabilizer, lens, moves the position of image stabilizer, lens 105 with the image on the dollying element 111 along the direction vertical with optical axis in image pickup optical system.Except that such, can also use the lens of the ad-hoc location rotation on the optical axis or so-called variable angle prism (variable-angle prism) as image stabilizer, lens 105.

Reference numeral 212 illustrates the image stabilization control circuit that is arranged in the microcomputer 130, and it is based on the driving of controlling image stabilizer, lens 105 by image stabilizer, lens drive circuit 213 from the output of rocking detecting sensor 211.Particularly, 212 pairs of image stabilization control circuits carry out integration from the signal (for example, angular velocity signal) that rocks that rocks detecting sensor 211, to calculate amount and the direction that camera rocks.Image stabilization control circuit 212 determines to offset because required driving amount and the direction to image stabilizer, lens 105 of skew that camera rocks the subject image that causes outputs to image stabilizer, lens drive circuit 213 with the image stabilization signal of representing driving amount and direction.

In response to this signal, for example drive image stabilizer, lens 105 along the direction vertical with optical axis, rock to reduce image.

Image stabilization control circuit 212 will rock also that detecting sensor 211 is detected to be had or not camera to rock to send to AF control circuit 131.

When having the subject of video camera photographic images in the detection visual field of distance measuring sensor unit 141 externally, the correlation (the highest correlation) in the outside distance measuring sensor unit 141 changes according to the variation of rocking detected state of promptly rocking detecting sensor 211 of rocking relatively that detects between the visual field and the subject.

Yet when externally having barrier between distance measuring sensor unit 141 and the subject, correlation does not change according to the variation of rocking detected state of rocking.In embodiment 8, use this situation to judge whether to exist barrier.

Then, the AF control of being undertaken by the microcomputer 130 that comprises AF control circuit 131 with reference to the flowchart text among Figure 23.

At S1300, microcomputer 130 beginning AF controls.For example, carry out the processing shown in this flow chart at the readout interval of reading image pickup signal from the imaging apparatus 111 of the image that is used for producing a visual field.

At S1320, detecting sensor 211 is rocked in microcomputer 130 startups, makes the driving of image stabilization control circuit 212 controls to image stabilizer, lens 105.

At S1301, microcomputer 130 judges whether to have reached focus state.Reached focus state if be judged as, then flow process enters S1308, otherwise, do not reach focus state if be judged as, then enter S1302.Can judge by the focusing in the TV-AF operation and carry out the judgement of focus state.

At S1302, microcomputer 130 judges whether focusing lens 104 is in the processing of the focusing operation that utilizes outside range finding AF.If focusing operation, then flow process enters S1308, otherwise, if focus operation, then enter S1303.

At S1303, microcomputer 130 carries out the TV-AF operation shown in the flow chart of Fig. 8.

At S1304, the current location of focusing lens 104 and the focal position that is calculated based on the subject range information that is provided by outside distance measuring sensor unit 141 are provided microcomputer 130, judge the current location of focusing lens 104 and the focal position that calculated between difference whether greater than predetermined value.If be somebody's turn to do difference greater than predetermined value, then microcomputer 130 is judged as focusing lens 104 away from focal position, and flow process enters S1305.If this difference is equal to or less than predetermined value, then microcomputer 130 is judged as focusing lens 104 and is positioned at focal position, and flow process enters S1308.

At S1305, microcomputer 130 rocks based on judging whether to have taken place camera from the output of rocking detecting sensor 211.Rock (that is to say, if rock detected state variation has taken place) if camera has taken place, then flow process enters S1309, otherwise, if taking place, do not rock by camera, then enter S1308.In order to prevent frequently to switch between TV-AF and outside range finding AF, can whether the judgement that camera rocks take place by judging whether changed scheduled volume or more from the output of rocking detecting sensor 211.

At S1309, microcomputer 130 judges whether correlation that outside distance measuring sensor unit 141 provides is followed the variation of rocking detected state and changed.Correlation and rock corresponding relation between the detected state and be similar to corresponding relation between aperture control signal shown in Figure 19 and the light-receiving luminance level.

When correlation is followed the variation of rocking detected state and is changed, be judged as the suitable light-receiving state that has reached the subject range information that is used to provide correct in the distance measuring sensor unit 141 externally, flow process enters S1306.When correlation does not change according to the variation of rocking detected state, be judged as the suitable light-receiving state that does not reach the subject range information that is used to provide correct in the distance measuring sensor unit 141 externally, handle entering S1308.

At S1306, whether microcomputer 130 is judged from the direction of the outside range finding focal position that the subject range information that is provided by outside distance measuring sensor unit 141 is calculated identical with the correct moving direction that (S1005 among Fig. 8) TV-AF at S1303 handles judged.If they are identical, the subject distance detection result who then is judged as outside distance measuring sensor is correct, and flow process enters S1307, otherwise, if their differences then enter S1308.

At S1307, microcomputer 130 moves to outside range finding focal position with focusing lens 104.This can utilize outside range finding AF to reach focus state or approximate focus state.

At S1308, microcomputer 130 finishes this flow process.

As mentioned above, in embodiment 8, detect rocking relatively between the detection visual field of outside distance measuring sensor unit 141 and the subject with reference to rocking detected state.Do not change by detecting the correlation relevant, be judged as externally and have barrier between the distance measuring sensor unit 141 and subject according to detecting rocking relatively between the visual field and the subject with the light-receiving state of outside distance measuring sensor unit 141.In this case, outside range finding AF can be limited, the TV-AF control of focusing accurately can be utilized to avoid wrong focusing control.Consequently, can realize level and smooth focusing control.

When not having camera to rock, that is to say that when subject image (photographic images) when not changing, the outside range finding of restriction AF carries out TV-AF.Therefore, under the situation except the situation that has barrier as mentioned above, can carry out level and smooth focusing control.

At judging whether the correlation that provides in the distance measuring sensor unit 141 externally follows the variation of rocking detected state and situation about changing illustrated embodiment 8.Yet,, can judge whether light-receiving luminance level in the outside distance measuring sensor unit 141 is followed the variation of rocking detected state and changed as illustrated among the embodiment 6.

According to embodiment 6～8, when the light-receiving state of second detector not in response to the state of a control of aperture or color balance or rock the variation of detected state and when changing, restriction is based on the focusing control of second information.When for example owing to having barrier to cause can not to provide the second correct information between second detector and subject, this can be avoided wrong focusing control, thereby makes it possible to the focus state that reaches correct.

And the present invention is not limited to these preferred embodiments, can make various modifications and distortion and does not depart from the scope of the present invention.

Claims (2)

1. picture pick-up device comprises:

First detector, it produces and the corresponding first information of contrast state that uses the photographic images that imaging apparatus produced;

Second detector, it receives from the light of subject to detect and corresponding second information of distance to subject;

The focusing controller, it uses the control of focusing of the described first information and described second information; And

The aperture controller, its control is used to regulate the aperture of the light quantity that enters described imaging apparatus,

Wherein, when according to described aperture controller the variation of the state of a control of described aperture not being changed about the information of the light-receiving state of described second detector, described focusing controller uses the described first information and does not use the control of focusing of described second information.

2. the focus control method of a picture pick-up device comprises:

Obtain and use the step of the corresponding first information of contrast state of the photographic images that imaging apparatus produces;

Use reception from the detector acquisition of the light of subject and the step of corresponding second information of distance that arrives subject;

The focusing controlled step, it uses the control of focusing of the described first information and described second information; And

The aperture controlled step, its control is used to regulate the aperture of the light quantity that enters described imaging apparatus,

Wherein, described focusing controlled step comprises: when according to described aperture controlled step the variation of the state of a control of described aperture not being changed about the information of the light-receiving state of described detector, use the described first information and do not use the control of focusing of described second information.

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