JP2001264620A - Multipoint range-finding camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multipoint range-finding camera capable of performing range-finding in two areas even when subject luminance is largely different by alternately performing optimum storing operation in both areas, respectively. SOLUTION: In the case a lens is not driven, a CPU 7 judges the previous range-finding area and selects an area A when the previous range-finding area is an area B or this range-finding is the first one. Then, the CPU 7 stores and transfers it so as to perform range-finding arithmetic operation. Based on the range-finding results of the areas A and B, the area on a close range side is selected. In the case the lens is driven, the CPU 7 selects the selected area on the close range side again, and performs storing, transferring and range- finding arithmetic operation in the same manner, then selects the same area as the previous one because the lens is driven. Since optimum storing operation is alternately performed in plural areas, range-finding is performed in the area even when the subject luminance is largely different in the respective areas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-point distance measuring camera in which optical systems are arranged so that luminous fluxes of a plurality of object areas on a predetermined focal plane enter different areas of one or more distance measuring elements.

[0002]

2. Description of the Related Art In a multi-point distance measuring camera, for example, in order to reduce costs and reduce the size, a configuration may be adopted in which light beams at two distance measuring points are guided to one distance measuring element. In such a case,
If the subject luminances at the two distance measurement points are significantly different, the optimum accumulation operation cannot be performed simultaneously in both areas, and one of them may not be able to perform distance measurement.

[0003]

In such a case, a focusing operation is performed on an area where distance measurement can be performed.
There is a problem that there is a restriction in selecting an area for a plurality of areas. An object of the present invention is to provide a multi-point ranging camera capable of performing distance measurement in both areas even when subject brightness greatly differs by alternately performing an optimal accumulation operation in each of two areas. is there.

[0004]

In order to achieve the above object, a multi-point distance measuring camera according to the present invention comprises: a distance measuring element for detecting a defocus amount of a limited area in a predetermined focal plane; Control means for controlling accumulation / transfer of the distance measuring element, a conversion device for converting an electric signal corresponding to the contrast of the object obtained by using the distance measuring element and the control means into pixel digital data, A calculating device for calculating a defocus amount based on the obtained pixel digital data, and a lens drive control device for driving a lens by a predetermined amount based on the defocus amount obtained by the calculating device. In a multi-point distance-measuring camera having an optical system arranged so that a light beam of an object area is incident on different areas of one or more distance-measuring elements, a plurality of objects incident on the distance-measuring elements are provided. The defocus amount is detected in two or more of the plurality of distance measurement areas corresponding to the luminous flux of the body area, and a series of operations of accumulation, transfer, and calculation are performed for one distance measurement area. A control means is provided for performing a ranging operation by switching the ranging area to another ranging area for each series of operations. According to the present invention, in the above configuration, the information for detecting the defocus amount in the two or more areas and performing the accumulation control performed on one ranging area includes information for performing the previous ranging operation in the ranging area. Operation means for performing an operation based on the information at the time of occurrence. According to the present invention, in the above-described configuration, the information at the time of performing the last distance measurement operation includes an accumulation time and pixel digital data. According to the present invention, in the above configuration, when the lens is driven to the in-focus position based on the obtained defocus amount, the selecting means for selecting one of the plurality of ranging areas immediately before the driving is provided. Have
When the lens is driven, a series of distance measuring operations of accumulation, transfer, and calculation are performed for only one distance measuring area selected by the selecting means.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1A and 1B are diagrams showing an embodiment of a distance measuring unit of a multipoint distance measuring camera according to the present invention, wherein FIG. 1A shows an example of a finder display, and FIG. 1B shows a configuration of an optical system of a distance measuring element. is there. In this embodiment, distance measurement areas A and B are arranged near the center of the finder 1. The luminous flux in the area A5 passes through the lens 2a for distance measurement, and further passes through the lens 4a.
The light is separated into two subject images by ₁ and 4a ₂ and is incident on a light receiving section 3a of a distance measuring element (CCD line sensor) 3. On the other hand, the light flux regions B6 is through the lens 2b for distance measurement, further lens 4b _1, the 4b ₂ is separated into two object images incident on the light-receiving portion 3b of the distance measurement device (CCD line sensor) 3.

FIG. 2 is a block diagram showing an embodiment of the circuit of the multipoint distance measuring camera according to the present invention. Light incident on the light receiving section A3a corresponding to the area A5 and the light receiving section B3b corresponding to the area B6 of the distance measuring element 3 is accumulated / transferred under the control of the accumulation / transfer control section 10 and converted into digital data by the AD conversion section 9. Is done. The CPU 7 performs a distance measurement operation based on an area switching determination unit 7a that performs area switching determination, an area selection unit 7b that selects an area for driving a lens, and accumulated digital data, previous accumulation time, and data on the amplification of the amplifier. Has a function of a distance measurement arithmetic circuit 7C that performs the following. The areas A and B are alternately selected by the area switching determination unit 7a,
The data is accumulated and transferred by the transfer control unit 10. Then, distance calculation is performed by the distance measurement calculation circuit 7C. In this manner, the optimum accumulation / transfer and arithmetic processing are performed alternately for each area, and the area selection unit 7b selects which area to use for driving the lens immediately before driving the lens. In the selection, the closest side is selected from the distance measurement results of the areas A and B.

FIG. 3 is a diagram for explaining an example of subject brightness in areas A and B. This is a case where the subject brightnesses of the areas A and B are significantly different, and the area A has higher brightness. (A)
Has a proper distance measurement waveform by controlling the accumulation time and the amplification degree for the area A and has an appropriate distance measurement waveform. On the other hand, in the accumulation time and the amplification degree for the area A, the waveform level of the area B is small. It becomes impossible to measure the distance. (B) shows a case where the control of the accumulation time and the amplification degree is optimized for the region B, and the distance measurement waveform is appropriate. In the case of the region A control, the waveform is saturated and the distance measurement is performed. Become impossible.

FIG. 4 is a flowchart for explaining the basic operation of the areas A and B. First, accumulation / transfer is performed for the area A (step (hereinafter referred to as "S") 40).
1) A distance measurement calculation is performed (S402). Then, the next accumulation condition of the area A is calculated (S403). That is, the data of the next optimum storage time and amplification degree is calculated based on the stored data. Next, the area is switched to the area B, accumulation / transfer is performed on the area B, and distance measurement calculation is performed (S4).
04, S405). Then, as in the case of the area A, the next accumulation condition is calculated (S406). Less than,
The operation of alternately switching the areas A and B to perform accumulation / transfer and calculation is repeated.

FIG. 5 is a diagram for explaining an example of selection of an area when driving a lens. When the accumulation / transfer and the arithmetic processing are repeatedly performed while the areas A and B are alternately switched, the closest side is selected by looking at the arithmetic results of the areas A and B immediately before the lens driving. In this example, the area B is determined to be on the close side, and the lens driving is performed based on the calculation result of the area B. Thereafter, the distance measurement calculation is repeated for the area B.

FIG. 6 is a flowchart for explaining the switching and selection operation of the distance measurement areas. Camera CP
U7 determines whether the lens is being driven (S6).
01). If the area switching determination unit 7a determines that the lens is not being driven or that the lens is being driven for the first time, the area switching determination unit 7a determines whether this is the first time, or the previous ranging area is A or B. (S602). If it is determined that the distance measurement area is B for the first time or the previous time,
Transfer is performed (S603). The distance calculation circuit 7c calculates the area A
Is calculated (S604), and the next accumulation condition of the area A is calculated (S605). Then, at the time of driving the lens, the area selecting means 7b selects one of the areas A and B. An area on the closest side is selected from the distance measurement results of the areas A and B (S6).
10).

If it is determined in step S602 that the distance measurement area is A last time, accumulation / transfer according to area B is performed (S607). The distance measurement calculation circuit 7c performs the distance measurement calculation of the area B (S608), and calculates the next accumulation condition (accumulation time and amplification) of the area B (S609). Then, the area selecting means 7b selects one of the areas A and B. Area A
Then, the closest side is selected from the distance measurement results of B and B (S610). S
If the area switching determination unit 7a determines in 601 that the lens is being driven, the area selected in S610 is selected (S610).
606). If the area A is selected, S603 and S60
The process shifts to S610 via 4, S605. When the area B is selected, the process shifts to S610 via S607, S608, and S609. In S610, since the lens is being driven, the same area as the previous time is selected.

In the above embodiment, when the lens is driven,
Although the example in which the area on the closest side is prioritized as a criterion for selection by the area selecting means has been described, the area may be selected based on another selection criterion. For example, an area on which accumulation / transfer and calculation have been performed immediately before driving the lens may be selected.

[0013]

As described above, according to the present invention, the defocus amount is detected in two or more of the plurality of ranging areas corresponding to the luminous flux of the plurality of subject areas incident on the ranging element. Control means for performing a series of operations of accumulation / transfer / operation on one ranging area, and switching the ranging area to another ranging area for each series of operations to perform a ranging operation. Have. Therefore, there is an effect that distance measurement can be performed in each area even when the subject brightness in two or more areas is significantly different.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing an embodiment of a distance measuring unit of a multipoint distance measuring camera according to the present invention, wherein FIG.
FIG. 3 is a diagram showing a configuration of an optical system of a distance measuring element.

FIG. 2 is a block diagram showing an embodiment of a circuit of the multipoint distance measuring camera according to the present invention.

FIG. 3 is a diagram for explaining an example of subject brightness in areas A and B;

FIG. 4 is a flowchart for explaining a basic operation of areas A and B.

FIG. 5 is a diagram for explaining an example of selection of an area when driving a lens.

FIG. 6 is a flowchart for explaining switching and selection operations of a ranging area.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Finder 2a, 2b ... Lens 3 ... Distance measuring element 5 ... Area A 6 ... Area B 7 ... CPU 7a ... Area switching judgment part 7b ... Area selecting means 7c ... Distance measuring arithmetic circuit 8 ... Lens driving device 9 ... AD conversion Unit 10: Storage / transfer control unit

Claims (4)

[Claims] A distance measuring element for detecting a defocus amount of a limited area in a predetermined focal plane; a control means for controlling accumulation / transfer of the distance measuring element; and a distance measuring element and a control means. A conversion device for converting an electric signal corresponding to the contrast of the object obtained by using the conversion device into pixel digital data, a calculation device for calculating a defocus amount based on the pixel digital data converted by the conversion device, and the calculation device. A lens drive control device that drives the lens by a predetermined amount based on the obtained defocus amount so that light fluxes of a plurality of subject regions on the planned focal plane enter different regions of one or more distance measuring elements; In a multi-point distance measuring camera in which an optical system is arranged, two or more of a plurality of distance measuring areas corresponding to luminous fluxes of a plurality of object areas incident on the distance measuring element are deformed. Detects the amount of scum, performs a series of operations of accumulation, transfer, and operation on one ranging area, and switches the ranging area to another ranging area for each series of operations to perform ranging. A multi-point distance measuring camera comprising a control unit for performing 2. The information for detecting a defocus amount in the two or more areas and performing storage control for one ranging area includes information on a previous ranging operation performed in the ranging area. 2. A multi-point distance measuring camera according to claim 1, further comprising a calculating means for calculating based on said information. 3. The information at the time of performing the last ranging operation is as follows.
3. The multi-point distance measuring camera according to claim 2, wherein the camera is an accumulation time and pixel digital data. 4. When the lens is driven to an in-focus position based on the obtained defocus amount, there is provided a selecting means for selecting one of a plurality of ranging areas immediately before driving. 2. A multi-point distance measuring camera according to claim 1, wherein, when the lens is driven, a series of distance measuring operations of accumulation / transfer / operation are performed only for one distance measuring area selected by said selecting means. .