JP3074502B2 - Camera ranging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera distance measuring apparatus, and more particularly to a camera distance measuring apparatus provided with distance measuring means for outputting center distance data and left and right peripheral distance data.

[0002]

2. Description of the Related Art A conventional camera distance measuring apparatus is disclosed in Japanese Unexamined Patent Publication No. 1-259-1990, in which when a center is located farther than a predetermined value, a left and right peripheral part is measured.
Japanese Patent Application Laid-Open No. 2-2725 discloses a method for controlling the extension of a photographing lens based on the measurement result at the center when the measurement results at the left and right peripheral portions are close to each other.
No. 26 is disclosed in a camera distance measuring device.

In order to improve the distance measurement accuracy and reliability of a camera distance measuring device, for example, in an active AF camera, a method of brightening a light projecting lens and a light receiving lens in order to improve the distance measuring accuracy on a long distance side. There is a method of extending the distance measurement time, using an average value of the distance measurement data of a plurality of times, a method of increasing the current supplied to the light emitting element, and the like. There is a difficulty in increasing the size. In addition, a method of extending the distance measurement time and using an average value of a plurality of distance measurement data results in a loss of shutter change due to an increase in the distance measurement time, impairs a camera's quick shooting performance, and causes an error in a moving subject. There are disadvantages such as easy ranging. In addition, the method of increasing the current flowing through the light emitting element has a drawback that the battery life is shortened due to an increase in current consumption. Further, the distance measuring means that outputs the center distance data and the left and right peripheral distance data has a drawback in that if there is an obstacle around the image frame, the distance is erroneously measured and a clear image cannot be captured.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the conventional camera distance measuring apparatus. By providing peripheral distance data determining means for determining whether or not the distance is within the range of the reference distance data and the far-side reference distance data, the distance measurement time can be shortened, the quick shooting performance can be improved, and the current supplied to the light emitting element can be increased. It is an object of the present invention to provide a camera distance measuring device capable of capturing clear images by reducing the number of times, prolonging the battery life, and optimizing a hollowing out prevention function that is hardly affected by short-range obstacles.

[0005]

According to the present invention, there is provided a distance measuring means for measuring a distance to an object and outputting center distance data and left and right peripheral distance data, and a central part outputted from the distance measuring means. A central distance data comparing means for comparing the distance data with the predetermined central reference distance data; and left and right peripheral distance data output from the distance measuring means, wherein the predetermined near-side reference distance data and the far-side distance data are used. A lens based on peripheral drive data generated according to the comparison and determination by the peripheral distance data determining means and the central distance data comparing means and the peripheral distance data determining means for determining whether or not the distance is within the range of the reference distance data; And a control means for controlling the feeding amount.

[0006]

The distance to the subject is measured by the distance measuring means, and the center distance data and the left and right peripheral distance data are output. The distance to the object at the center measured by the center distance data comparing means is compared with the center reference distance data. Further, the peripheral distance data determining means determines whether or not the measured left and right peripheral distance data are within a predetermined range of the near-side reference distance data and the far-side reference distance data. The control means controls the amount of extension of the lens based on the lens drive data generated in accordance with the comparison and determination by the central distance data comparing means and the peripheral distance data determining means.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a camera distance measuring apparatus according to the present invention.

As shown in FIG. 1, a distance measuring device for a camera according to the present invention has a light emitting diode 2 for projecting light from a light projecting lens 2a to a subject, and a light receiving lens 3a for reflecting light reflected by the subject.
Light-receiving element 3 for receiving light through the light-emitting diode 2 for distance measurement
The right peripheral reflected light f _R , the central reflected light f _C , and the left peripheral reflected light f _L are input from the AFIC 1 to which the light receiving element 3 is connected, and the central peripheral distance data CD, the right peripheral distance data RD, distance data analyzing circuit outputs a left peripheral distance data LD 4, the central portion reference distance central reference distance data generator 5 for generating data D _2, the near-side reference distance data generator for generating a near-side reference distance data D ₁ 6, the far-side reference distance data D ₃ far side reference distance data generator 7 for generating a central portion distance data CD outputted from the distance data analysis circuit 4
Central distance data comparison circuit 8, the right periphery distance data RD is near side reference distance data D for comparing the central reference distance data D ₂ output from the central reference distance data generator 5 and
Determining right periphery whether in the range of ₁ and the far-side reference distance data D ₃ distance data judging circuit 9, reference near the left periphery distance data LD side distance data D ₁ and the far-side reference distance data D _{Between the} left peripheral distance data determining circuit 10, the central peripheral distance data comparing circuit 8, the right peripheral distance data determining circuit 9, and the left peripheral distance data determining circuit 10 for determining whether or not they are within the range of _3. Drive data register 11, CPU 20, CPU 2 for transmitting / receiving accumulated drive data DD
The lens drive IC 13 extends the lens 15 of the lens barrel 14 under the control of 0.

The control side of the CPU 20 is connected to the AFIC 1 and the distance data analyzing circuit 4, and the central distance data comparing circuit 8, the right peripheral distance data determining circuit 9, the left peripheral distance data determining circuit 10, and the drive data register 11 The CPU 20 is connected to the CPU 20 through control lines C _{1 to} C ₄ , and each wiring logic is advanced in the sequence shown in FIG. Then, the center distance data CD output from the distance data analysis circuit 4 is stored in the drive data register 11. Now, the accumulated center distance data C
Comparing the D and the center reference distance data D _2, the central portion distance data CD is transmitted to the CPU20 exits the drive data DD of if within a central reference distance data D _2. CP
U20 extends the lens 15 of the lens barrel 14 with the input drive data DD, that is, the center distance data CD.

The center distance data CD and the center reference distance data D ₂ stored in the above are compared, and the center distance data C ₂ is compared.
D it is determined whether the time central larger reference distance data D ₂ is in there is far-side reference distance data D ₃ and the right periphery distance data RD in the range of near-side reference distance data D _1,
Then, the drive data DD, that is, the center distance data CD and the right peripheral distance data RD are compared. When the right peripheral distance data RD is smaller than the drive data DD, the right peripheral distance data RD is stored in the drive data register 11, and the same comparison is performed as when the left peripheral distance data LD is used. In the left peripheral distance data LD, the right peripheral distance data R within the range of the drive data DD (far-side reference distance data D ₃ and near-side reference distance data D ₁ ).
D or the central part distance data CD smaller than the central part reference distance data D ₂ ), the left peripheral part distance data LD is stored in the drive data register 11. Data DD
Of (far side reference distance data D ₃ and near-side reference distance in the range of the data D ₁ right periphery distance data RD or central reference distance data D ₂ is smaller than the central portion distance data CD is stored) The minimum left peripheral distance data LD, the right peripheral distance data RD, and the central distance data CD are drive data DD.

Here, the near-side reference distance data D ₁ is 2 m,
6m central portion reference distance data D _2, the far-side reference distance data D ₃ and 8m, right periphery reflected light f _R, central reflected light f _C,
The distance to the subject that reflects the left peripheral reflected light f _L is shown in FIG.
As shown in the figure, if they are 5m, 9m and 4m respectively,
The minimum left peripheral distance data LD is stored in the drive data register 11 and the 4 m drive data DD is stored in the CPU 2.
Sent to 0. As shown in FIG. 4, to shoot a left peripheral portion PL of the photographing frame W _1, when there is an obstacle such as a window on the right peripheral portion PR, the subject example building central PC.

[0012]

By implementing the algorithm based on the wiring logic under the control of the CPU, it is possible to shorten the distance measurement time, improve the quick shooting performance, reduce the current supplied to the light emitting element, extend the life of the battery, and shorten the distance. There is an effect that the clearing prevention function, which is hardly affected by obstacles, is optimized and a clear image can be captured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a camera distance measuring apparatus according to the present invention.

FIG. 2 is a flowchart showing an embodiment of an algorithm based on wiring logic of the camera distance measuring apparatus of the present invention.

FIG. 3 is a configuration diagram showing a range of reference distance data of the camera ranging device of the present invention.

FIG. 4 is a configuration diagram of a photographing frame of the camera ranging device of the present invention.

[Explanation of symbols]

8 ... Central distance data comparing circuit (central distance data comparing means) 9 ... Right peripheral distance data determining circuit (peripheral distance data determining means) 10 ... Left peripheral distance data determining circuit (peripheral) Unit distance data determination means) 20 CPU (control means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-259313 (JP, A) JP-A-2-272526 (JP, A) JP-A-63-291043 (JP, A) JP-A-62-1987 255911 (JP, A) JP-A-2-282234 (JP, A) JP-A-63-266434 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 7/32 G01C 3 / 06 G03B 13/36

Claims (1)

(57) [Claims] 1. A distance measuring means for measuring a distance to a subject and outputting center distance data and left and right peripheral distance data, and a center distance data outputted from said distance measuring means and predetermined. A central distance data comparing means for comparing the central reference distance data, and the left output from the distance measuring means,
Peripheral distance data determining means for determining whether the right peripheral distance data is within a predetermined range of near-side reference distance data and far-side reference distance data, the central distance data comparing means, and the periphery Control means for controlling a lens extension amount based on lens drive data generated in accordance with the comparison and determination by the unit distance data determining means.