Apparatus and method for finding optimal zooming speed

Patent metadata

Field	Value
Publication number	US-9503651-B2
Application number	US-201514805933-A
Country	US
Kind code	B2
Filing date	Jul 22, 2015
Priority date	Sep 30, 2014
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

An optimal zooming speed determining device includes: a storage to store a zooming speed at each position of a zoom lens; a tracking implementer to calculate a position of the zoom lens changed in a unit time at a zooming speed at each position of the zoom lens; a moving time calculator to calculate a difference between a position of a focus lens corresponding to a position of the zoom lens before the position of the zoom lens is changed and a position of the focus lens corresponding to the changed position of the zoom lens, and calculate a focus moving time by dividing the difference between positions of the focus lens by a highest moving speed of the focus lens; and a zooming speed determiner to reduce the zooming speed at each position of the zoom lens, if the focus moving time is greater than the unit time.

First claim

What is claimed is:

1. An optimal zooming speed determining device comprising:
a storage configured to store a zooming speed at each position of a zoom lens;
a tracking implementer configured to calculate a position of the zoom lens changed in a unit time at a zooming speed at the each position of the zoom lens;
a moving time calculator configured to calculate a difference between a position of a focus lens corresponding to a position of the zoom lens before the position of the zoom lens is changed and a position of the focus lens corresponding to the changed position of the zoom lens, and calculate a focus moving time by dividing the difference between positions of the focus lens by a highest moving speed of the focus lens from among a plurality of preset moving speeds of the focus lens; and
a zooming speed determiner configured to reduce the zooming speed at the each position of the zoom lens stored in the storage, if the focus moving time is greater than the unit time.

2. The optimal zooming speed determining device of claim 1 , wherein the zooming speed at the each position of the zoom lens is calculated from locus data regarding a distance between an object and a zoom lens system comprising the zoom lens and the focus lens.

3. The optimal zooming speed determining device of claim 2 , wherein the locus data comprises:
locus data corresponding to a case at which the object is located at an infinite distance from the zoom lens system;
and locus data corresponding to a case at which the object is a minimum object distance (MOD) distance from the zoom lens system,
and wherein the MOD distance is a smallest distance with guaranteed resolving power.

4. The optimal zooming speed determining device of claim 1 , wherein the zooming speed determiner is configured to reduce the zooming speed at the each position of the zoom lens by changing a position of the zoom lens corresponding to each zooming speed.

5. The optimal zooming speed determining device of claim 1 , wherein, at the storage, the position of the zoom lens corresponds to a section of the zoom lens comprising a plurality of positions of the zoom lens, and
wherein the zooming speed determiner is configured to change positions of the zoom lens corresponding to respective zooming speeds.

6. The optimal zooming speed determining device of claim 5 , wherein the zooming speed determiner is configured to sequentially change a plurality of sections of the zoom lens corresponding to the respective zooming speeds from a section of the zoom lens corresponding to a lowest zooming speed to a section of the zoom lens corresponding to a highest zooming speed,
wherein each of the sections of the zoom lens comprises a plurality of positions of the zoom lens, and
wherein the lowest and highest zooming speeds are selected from among a plurality of zooming speeds at respective positions of the zoom lens stored in the storage.

7. The optimal zooming speed determining device of claim 1 , wherein the zooming speed determiner is configured to cumulatively change a plurality of sections of the zoom lens corresponding to respective zooming speeds by a pre-set margin value from a section of the zoom lens corresponding to a lowest zooming speed to a section of the zoom lens corresponding to a highest zooming speed,
wherein each of the sections of the zoom lens comprises a plurality of positions of the zoom lens, and
wherein the lowest and highest zooming speeds are selected from among a plurality of zooming speeds at respective positions of the zoom lens stored in the storage.

8. The optimal zooming speed determining device of claim 7 , wherein the zooming speed determiner is configured to cumulatively change the plurality of sections of the zoom lens corresponding to the respective zooming speeds by the margin value from a section of the zoom lens corresponding to the lowest zooming speed to a section of the zoom lens corresponding to a reference zooming speed,
wherein the reference zooming speed is a zooming speed that is lower than the highest zooming speed, and
wherein the lowest and highest zooming speeds are selected from among a plurality of zooming speeds at respective positions of the zoom lens stored in the storage.

9. The optimal zooming speed determining device of claim 8 , wherein the reference zooming speed is a zooming speed corresponding to a position of the zoom lens at which a change of a range of the focus lens is greater than a pre-set value, and
wherein the range of the focus lens is a range to move the focus lens as the zoom lens moves.

10. The optimal zooming speed determining device of claim 7 , wherein the zooming speed determiner is configured to cumulatively change the plurality of sections of the zoom lens corresponding to the respective zooming speeds by a pre-set inverse margin value from a section of the zoom lens corresponding to a speed higher than the reference zooming speed to a section of the zoom lens corresponding to the highest zooming speed.

11. A method of determining an optimal zooming speed, the method comprising:
storing a zooming speed at each position of a zoom lens;
calculating a position of the zoom lens changed in a unit time at a zooming speed at the each the position of the zoom lens;
calculating a difference between a position of a focus lens corresponding to a position of the zoom lens before the position of the zoom lens is changed and a position of the focus lens corresponding to the changed position of the zoom lens, and calculating a focus moving time by dividing the difference between positions of the focus lens by a highest moving speed of the focus lens from among a plurality of preset moving speeds of the focus lens; and
reducing the zooming speed at the each position of the zoom lens, if the focus moving time is greater than the unit time.

12. The method of claim 11 , wherein the zooming speed at the each position of the zoom lens is calculated from locus data regarding a distance between an object and a zoom lens system comprising the zoom lens and the focus lens.

13. The method of claim 12 , wherein the locus data comprises:
locus data corresponding to a case at which the object is located at an infinite distance from the zoom lens system; and
locus data corresponding to a case at which the object is a MOD distance from the zoom lens system, and
wherein the MOD distance is a smallest distance with guaranteed resolving power.

14. The method of claim 11 , wherein the zooming speed at the each position of the zoom lens is reduced by changing a position of the zoom lens corresponding to each zooming speed.

15. The method of claim 11 , wherein the position of the zoom lens corresponds to a section of the zoom lens comprising a plurality of positions of the zoom lens, and
wherein the method further comprises changing positions of the zoom lens corresponding to respective zooming speeds.

16. The method of claim 15 , further comprising sequentially changing a plurality of sections of the zoom lens corresponding to the respective zooming speeds from a section of the zoom lens corresponding to a lowest zooming speed to a section of the zoom lens corresponding to a highest zooming speed,
wherein each of the sections of the zoom lens comprises a plurality of positions of the zoom lens, and
wherein the lowest and highest zooming speeds are selected from among a plurality of zooming speeds at respective positions of the zoom lens stored in the storage.

17. The method of claim 11 , further comprising cumulatively changing a plurality of sections of the zoom lens correspon

Assignees

• Hanwha Techwin Co Ltd
• Hanwha Techwin Co Ltd

Inventors

• Kim Daebong
• Kwon Youngsang
• Noh Joohye

Classifications

• G03B2205/0046

  Movement of one or more optical elements for zooming · CPC title

• G02B7/09

  adapted for automatic focusing or varying magnification · CPC title

• G02B15/00

  Optical objectives with means for varying the magnification (anamorphotic objectives G02B13/08) · CPC title

• G02B7/282

  Autofocusing of zoom lenses · CPC title

• H04N23/69 Primary

  Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming · CPC title