KR100229109B1 - Focus control device and method with controlling light responsible time and distance measuring number - Google Patents

Abstract

According to the present invention, there is provided a display device comprising: brightness sensing means for sensing a brightness around a subject, storage means for storing a set brightness and a counting value corresponding to the brightness sensed by the brightness sensing means, and a signal output from the brightness sensing means; Control means for judging the level of luminance around the subject, receiving a corresponding number of measurement distances from the storage means according to the determined level of the luminance around the subject, and outputting a control signal to perform the measurement by the number of measurement distances; Distance measuring means for detecting the contrast of the subject by driving a corresponding number of times according to the driving signal output from the means, and auxiliary light emitting light emitting the auxiliary light according to the control signal output from the control means when the brightness around the subject is low brightness. Means comprising the means according to the level of luminance around the subject By adjusting the sensitivity of the ranger, it is possible to reduce the difference in the response speed of the ranger, which varies depending on the level of luminance around the subject, and to vary the number of ranges according to the level of luminance around the subject, so that the luminance around the subject is low or high. Without changing the focusing operation time significantly, it has the effect of improving the range performance.

Description

Focusing device and method for controlling luminance response time and frequency of measurement

The present invention relates to a focusing control device and a method for controlling the luminance response time and the number of measurements, and compares the set luminance and the measured luminance to perform the number of measurement corresponding to the comparison value, so that the total time required for measurement is independent of the surrounding luminance. The present invention relates to a focusing device and a method for controlling the luminance response time and the number of measurements so as not to change significantly.

In general, the focusing apparatus is divided into an active method and a passive method.

The active method is a method in which the camera itself emits infrared rays or ultrasonic waves, and then detects light or waves incident on the subject and measures distance to the subject.

In addition, the passive method is a method of determining the distance of a subject by using the contrast difference of the input subject by receiving light from the subject under natural illumination without a light emitting part emitting light.

The range sensor used in the passive method is a means for detecting light emitted from a subject under natural lighting, and includes a plurality of photo cells, and the photo cell is a photo diode.

1 is an exemplary view showing luminance response time characteristics of a sensor of a conventional passive type auto focusing control.

In the above, the range sensor has a large change in response time according to the luminance. That is, the ranging sensor has a fast response time for the input luminance when the luminance around the subject is high, and a slow response time for the input luminance when the luminance around the subject is low. Big.

When the response time of the ranging sensor is long, the user may feel bored when taking a picture. Therefore, conventionally, as shown in the accompanying FIG. 1, by setting a limit time A to reduce the change in the response time of the above-mentioned ranging sensor, the response time of the ranging sensor according to the ambient luminance of the subject is adjusted. Limited treatment

That is, as shown in (1) and (2) of FIG. 1, when the response time of the ranging sensor exceeds the reference time A because the ambient luminance of the object is low, the error process or the auxiliary light is emitted to emit the luminance. Or brighten the response sensitivity of the range sensor to increase the brightness of the subject. In addition, if the response time of the ranging sensor does not exceed the reference time (A) because of high brightness as in (3), (4) and (5), the measurement is performed several times to improve the ranging performance.

However, in the related art, it is necessary to determine whether the response time of the ranging sensor is longer or shorter than the reference time as described above to perform the next step. And, in order to reduce the deviation of the performance of the focusing device, the average value is taken by repeating the distance measurement. At this time, the difference between the measurement operation time when the low brightness and the high brightness is increased according to the number of repeated distance measurement.

Thus, there is a problem in that the variation in the ranging performance is large because the number of repetitions is not large in the related art.

Accordingly, the present invention is to solve the conventional problems, the luminance response time and the number of measurements to adjust the sensitivity of the ranging sensor according to the ambient luminance, and to compare the set luminance and the measured luminance to determine the number of measurements according to the comparison value It relates to a focusing device for controlling and a method thereof.

1 is an exemplary view showing a luminance response time characteristic of a sensor of a conventional passive type auto focus control,

2 is a block diagram of a focusing apparatus for controlling luminance response time and counting frequency according to an embodiment of the present invention;

3 is a flowchart illustrating an operation of the focusing apparatus for controlling the luminance response time and the number of measurements according to an embodiment of the present invention.

The present invention as a means for solving the above technical problem

Brightness sensing means for sensing brightness around a subject;

Storage means for storing a set luminance and a counting frequency value corresponding to the luminance sensed by the luminance sensing means;

The level of luminance around the subject is determined by using the signal output from the luminance sensing means, and a control signal is input so that the distance is measured as much as the number of distance measurement from the storage means according to the determined level of the brightness around the subject. Control means for outputting;

Ranging means for driving a corresponding number of times according to a drive signal output from the control means to detect contrast of the subject;

When the luminance around the subject is low luminance, it comprises an auxiliary light emitting means for emitting an auxiliary light according to the control signal output from the control means.

The present invention as another means for solving the above technical problem is

Determining luminance around a subject;

Comparing and determining the set luminance and the luminance around the determined subject;

Determining whether to set the sensing means for detecting the contrast of the subject with high sensitivity or low sensitivity by comparing the luminance around the subject with the set luminance;

Determining the level of the luminance obtained from the ranging means;

Determining the number of measurements according to the determined level of luminance;

Comprising a step of calculating the average value of the ranging signal according to the determined number of measurements is made to perform the focus adjustment according to the calculated average value.

By the above-described configuration, a person having ordinary skill in the art to which the present invention pertains will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a focusing apparatus for controlling luminance response time and counting frequency according to an embodiment of the present invention;

3 is a flowchart illustrating an operation of the focusing apparatus for controlling the luminance response time and the number of measurements according to an embodiment of the present invention.

As shown in FIG. 2, the focusing apparatus for controlling the luminance response time and the number of measurements according to the embodiment of the present invention

A release switch S1;

A luminance sensing unit (1) comprising a CdS (Gadsulfide Sulfide) cell, which is a photoelectric conversion element, and outputting a voltage having a corresponding magnitude according to the intensity of light around an input object;

EEPROM (Electirically Erasable and Programmable Read Only Memory) capable of writing or erasing information by an electrical means, and stores a set luminance to be compared with the luminance sensed by the luminance detector 1, and the luminance detector 1 Storage unit 2 storing first switching luminance and second switching luminance for determining a corresponding number of measurement distances according to the luminance detected by the < RTI ID = 0.0 >) and < / RTI >Wow;

The luminance around the subject is determined by receiving the signal output from the luminance sensing unit 1 according to the on operation signal of the release switch S1, and the luminance around the subject is received by receiving the set luminance signal from the storage unit 2. And a control unit (3) for comparing and determining a set luminance signal to obtain a counting number corresponding to the comparison value from the storage unit (2), and outputting a control signal to perform the counting as much as the counting number;

And a ranging sensor 41 configured to detect contrast occurring in the subject, and perform the sensing of the contrast of the subject according to a control signal output from the controller 3 by a corresponding number of measurement times. )Wow;

And an auxiliary light emitting part 5 for emitting auxiliary light in order to increase the brightness around the subject according to the driving signal output from the controller 3 determining that the peripheral brightness of the subject is low brightness.

As shown in FIG. 5, the focusing apparatus for controlling the luminance response time and the number of measurements according to the embodiment of the present invention

Detecting brightness of the release switch S1 and determining luminance around the subject (S100);

Reading set luminance stored in the storage unit 2 (S200);

Comparing the determined luminance around the subject with the set luminance (300);

If the peripheral luminance of the subject is lower than the set luminance, making the sensitivity of the ranger highly sensitive (410);

If the peripheral luminance of the subject is higher than the set luminance, making the sensitivity of the ranging unit 4 high sensitivity (420);

Comparing the surrounding luminance of the subject with the first switching luminance (500);

Comparing the surrounding brightness of the subject with the second switching brightness (S600);

If the peripheral luminance of the subject is greater than the second switching luminance, determining the first case (S710);

Determining that the second luminance is less than the second switching luminance and larger than the first switching luminance (S720);

If the peripheral luminance of the subject is less than the first switching luminance, determining the third case (S730);

Setting the number of times of surveying to eight in the first case (S810);

Setting the number of times of surveying to 4 in the second case (S820);

Emitting an auxiliary light in a third case (S830);

(S840) setting the number of times of surveying to be twice in the third case;

Comprising a step (S900) to adjust the focus by calculating the average range.

With reference to the accompanying Figures 2 and 3 will be described the operation of the focusing apparatus for controlling the luminance response time and the number of measurements according to an embodiment of the present invention.

When the user presses the release switch S1 to take a picture, the release switch S1 is turned on to output an on signal to the controller 3.

The controller 3 receives the on signal of the release switch S1 and receives a signal output from the luminance sensor 1 to measure the luminance around the subject.

The luminance sensing unit 1 includes a CdS cell, which is a photoelectric conversion element in which electromotive force is generated or an electrical resistance is generated according to the intensity of input light. As described above, the luminance detector 1 including the CdS cells detects the intensity of light around the subject and outputs a voltage signal having a corresponding magnitude to the controller 3.

The controller 3 receives a voltage signal output from the luminance detector 1 to determine the surrounding luminance of the subject. The control signal is output to the storage unit 2 to determine whether the determined peripheral luminance of the subject is greater than or less than the set luminance.

The storage unit 2 is an EEPROM capable of writing or erasing information by an electrical means. The storage unit 2 receives a control signal output from the control unit 3 and outputs a voltage signal corresponding to the stored set luminance to the control unit 3. .

The controller 3 receives a signal output from the storage unit 2 and determines the set luminance.

Then, the controller 3 compares the determined set luminance with the surrounding luminance of the subject, and determines that the surrounding luminance of the subject is higher than the set luminance when the surrounding luminance of the subject is higher than the set luminance. Outputs (S300)

The ranger 4 includes a range sensor 41 for detecting contrast occurring in a subject. The range detector 4 reduces the sensitivity of the range sensor 41 according to the control signal of the controller 3 (S410).

The controller 3 outputs a control signal to the ranging unit 4 when the luminance around the subject is less than the set luminance. The range detector 4 makes the sensitivity of the range sensor 41 highly sensitive according to a control signal output from the controller 3 (S420).

The controller 3 controls the ranger 4 to have a corresponding sensitivity according to the surrounding luminance of the subject, and then compares the storage unit 2 to compare the surrounding luminance of the subject with the first switching luminance and the second switching luminance. Outputs a control signal.

The storage unit 2 stores the first switching luminance and the second switching luminance, and outputs them to the controller 3 according to a control signal of the controller 3.

The controller 3 first compares the luminance around the subject with the first switching luminance. The first switching signal has a set luminance value which is not large (S500).

In the case where the ranging sensor 41 is low, the peripheral luminance of the subject is higher than the first switching signal. If the peripheral luminance of the subject is higher than the first switching luminance, the controller 3 compares the second switching luminance, which is a set large luminance value, with the subject surrounding luminance.

First, consider a case where the peripheral luminance of the subject is greater than the second switching luminance in the comparison between the peripheral luminance of the subject performed by the controller 3, the first switching luminance, and the second switching luminance.

The controller 3 determines that the first case where the peripheral luminance of the subject is very large. If it is determined that the control unit 3 is the first case, the control unit 3 outputs a control signal to the storage unit 2 (S710).

The storage unit 2 outputs to the control unit 3 a signal for the number of measurement times corresponding to the stored first case according to the control signal output from the control unit 3.

The ranging frequency corresponding to the first case is the response speed of the ranging sensor 41 for high brightness, that is, the total time required for the ranging by predicting the operating time, that is, the total response time for the luminance of the object of the ranging sensor 41. This is the number of times you set how many times the survey is possible.

The number of measurement times corresponding to the second and third cases described below is the number of measurement times already set by the same method as the number of measurement times corresponding to the first case.

The control unit 3 receives a signal for the number of surveying outputs from the storage unit 2, determines the number of surveying, and outputs a driving signal to the ranging unit 4 to perform the survey as many as the number of surveying. )

The ranging unit 4 is a state in which the sensitivity of the ranging sensor 41 configured by the control unit 3 is reduced, and according to the driving signal output from the control unit 3, the number of distances corresponding to the first case is determined. By driving, the contrast generated in the subject is sensed, and a signal of the detected contrast is output to the controller 3.

The controller 3 receives a signal about the contrast of the subject output from the ranger 4 and calculates the distance between the subject and the camera by the number of measurement times corresponding to the first case. The average of the values is calculated to get the distance between the subject and the camera.

Second, consider a case where the peripheral luminance of the subject is smaller than the first switching luminance in the comparison of the peripheral luminance, the first switching luminance, and the second switching luminance of the subject performed by the controller 3.

In the comparison, when the peripheral luminance of the subject is lower than the first switching luminance having low luminance, the controller 3 determines that the peripheral luminance of the subject is the third case having a very low luminance and controls the storage unit 2 with the low luminance. Output a signal (S730).

The storage unit 2 outputs the counting number corresponding to the third case to the control unit 3 again according to the control signal of the control unit 3.

The control unit 3 determines the number of measurement ranges corresponding to the third case using the signal output from the storage unit 3, outputs a driving signal to the auxiliary light emitting unit 5, and then drives the measurement unit 4. Outputs a signal (S830, S840)).

In the third case, since the luminance around the subject is low, that is, the luminance of natural light is low, the light is insufficient for the passive ranging and thus the contrast does not occur in the subject or the contrast is not detected by the light receiving element. .

As described above, the passive light is emitted to increase the peripheral luminance of the subject, thereby enabling passive ranging.

Therefore, when the auxiliary light emitting unit 5 emits the auxiliary light by the number of distances corresponding to the driving signal output from the control unit 3, the measuring unit 3 outputs a control signal output from the control unit 3. The contrast generated in the subject is detected, and a signal for the detected contrast is output to the controller 3.

The said measuring part 4 is the state adjusted by the said control part 3 with high sensitivity.

The controller 3 receives a signal about the contrast of the subject output from the ranger 4 and calculates the distance between the subject and the camera by the number of measurement times corresponding to the third case. The average of the values is calculated to get the distance between the subject and the camera.

Finally, consider a case where the peripheral luminance of the subject is greater than the second switching luminance and smaller than the first switching luminance in the comparison of the peripheral luminance, the first switching luminance, and the second switching luminance of the subject performed by the controller 3.

The controller 3 determines that the first luminance is neither large nor small. If it is determined that the control unit 3 is the second case, the control unit 3 outputs a control signal to the storage unit 2 (S720).

The storage unit 2 outputs to the control unit 3 a signal for the number of measurements corresponding to the second case stored according to the control signal output from the control unit 3.

The control unit 3 receives the signal for the number of surveying outputs from the storage unit 2, determines the number of surveying, and drives the surveying unit 4 to perform the survey as many as the number of surveying corresponding to the second case. Output a signal (S820).

The ranging unit 4 detects the contrast occurring in the subject by driving the measurement number corresponding to the second case according to the driving signal output from the controller 3, and outputs a signal for the detected contrast to the control unit 3. )

The controller 3 receives a signal about the contrast of the subject output from the ranger 4 and calculates the distance between the subject and the camera by the number of measurement times corresponding to the second case, The distance between the subject and the camera is obtained by calculating an average of the values (S900).

The number of times of measurement and the total distance of measurement, which vary according to the level of luminance around the subject as described above, are shown in Table 1 below.

Subject brightness 1 operating time Repeat operation time Total operating time V1> V4 60mS 8 480mS V3 <V1 <V4 120 mS 4 480mS V1 <V3 240mS 2 480mS

In Table 1, the one-time operation time is a response time with respect to the input luminance of the ranging sensor 41, and the total operation time is a value set with the overall response time with respect to the input luminance of the ranging sensor 41. to be.

According to the present invention, the sensitivity of the ranging sensor 41 of the ranging unit 4 is adjusted according to the level of the luminance around the subject, thereby reducing the response speed of the ranging sensor 41 that varies depending on the level of the surrounding luminance of the subject, By varying the number of measurement ranges according to the level of the surrounding luminance, the focusing operation time does not change significantly and the ranging performance is improved regardless of whether the luminance around the subject is low or high.

Claims (10)

Brightness sensing means for sensing brightness around a subject; Storage means for storing a set luminance and a counting frequency value corresponding to the luminance sensed by the luminance sensing means; The level of luminance around the subject is determined by using the signal output from the luminance sensing means, and a control signal is input so that the distance is measured as much as the number of distance measurement from the storage means according to the determined level of the brightness around the subject. Control means for outputting; Ranging means for detecting the contrast of the subject by driving a corresponding number of times according to the driving signal output from the control means; And an auxiliary light emitting means for emitting an auxiliary light according to a control signal output from the control means when the brightness around the subject is low brightness. The method of claim 1, wherein the storage means Focus control device that controls the luminance response time and the number of measurements, characterized by an EEPROM capable of writing or erasing information by electrical means. The method of claim 2, wherein the storage means A set luminance to be compared with a peripheral luminance of the subject to adjust the sensitivity of the ranging means, a first switching luminance of low luminance and a second switching luminance of high luminance, and a level of luminance around the subject for determining the level of the peripheral luminance of the subject; The focusing apparatus for controlling the luminance response time and the number of times of measurement, characterized in that the corresponding number of times of measurement is stored. The method according to claim 1, wherein the control means And a luminance response time and a number of measurement times, characterized in that the sensitivity of the measurement means is adjusted by comparing and determining the luminance around the subject with the set luminance of the storage means. The method according to claim 4, wherein the control means Controls the luminance response time and the number of measurement, characterized in that the distance between the subject and the camera is determined by calculating an average value by receiving a contrast signal generated in the object as many times as the number of luminance corresponding to the level of luminance around the object output from the measurement means. Focusing device. Determining luminance around a subject; Comparing and determining the set luminance and the luminance around the determined subject; Determining whether to set the sensing means for detecting the contrast of the subject with high sensitivity or low sensitivity by comparing the luminance around the subject with the set luminance; Determining what is the level of luminance obtained from the ranging sensor; Determining the number of measurements according to the determined level of luminance; A method for controlling the luminance response time and the number of times of measurement, including the step of calculating the average value of the range of signals according to the determined number of times of measurement and performing focus adjustment according to the calculated average value. The method according to claim 6, The step of determining whether to set the sensing means for detecting the contrast of the subject with high sensitivity or low sensitivity by comparing the luminance around the subject with the set luminance A method for adjusting the luminance response time and the number of measurements, characterized in that the measuring means is reduced when the surrounding luminance of the subject is greater than the set luminance, and the measuring means is sensitive when the surrounding luminance of the subject is smaller than the set luminance. The method according to claim 6, The determining of the level of the luminance obtained from the range sensor is And comparing the surrounding brightness and the second switching brightness of the subject, and comparing the surrounding brightness and the first switching brightness of the subject. The method according to claim 8, Determining how much the level of luminance obtained from the ranging means is The surrounding luminance of the subject is compared with the second switching luminance, and when the peripheral luminance of the subject is greater than the second switching luminance, the number of measurement is set as the first case, and again when the surrounding luminance of the subject is smaller than the second switching luminance. The luminance response characterized in that the number of measurement is set to the second case when the first switching luminance is larger than the first switching luminance, and the number of the measurement is set to the third case when the luminance around the subject is less than the first switching luminance. Focusing method to control time and counting. 10. The method of claim 9, wherein in the first case, the number of surveys is eight. In the second case, the number of surveys is four. In the third case, the focusing method of controlling the luminance response time and the number of distances is characterized in that the number of distances is twice.

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