JPS60128314U - automatic focus adjustment device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional automatic focus adjustment device suitable for implementing the present invention, Fig. 2 is an explanatory diagram of the state of focus after the subject has moved from the in-focus state, and Figs. 3 and 4. Figure 1 is an explanatory diagram of the distance measuring device of the automatic focus adjustment device when measuring the distance of a subject with a contrast pattern, Figure 3 shows the in-focus state, and Figure 4 shows the goldfish signal, but it is in front of the focus. Fig. 5 is a configuration diagram of an embodiment of the light receiving element for an automatic focus adjustment device according to the present invention, and Fig. 6 is a projected light spot on the element surface during contrast pattern distance measurement in the light receiving element of Fig. 5. 7 is a block diagram of an electric circuit for operating the automatic focus adjustment device of the present invention, and FIG. 8 is a configuration diagram of another automatic focus adjustment device suitable for implementing the present invention. be. 2... Focusing photographing lens group, 3... Light projection lens, 4
...Light emitting element, 5... Light receiving lens, 6... Light receiving element, 6aiy 6 azt 6 blv 6 b2
``Divided area of light receiving element, 7...Signal processing circuit, 8
...Microcomputer, 9...Motor, 27...Warning L
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Claims (1)

[Scope of utility model registration request] It has a light projecting means for projecting a light beam toward a subject, and a light receiving means for forming an image of the reflected light from the subject on a light receiving element divided into two areas, and the output signals from the two areas are used to detect the subject. In an automatic focusing device configured to operate to focus on the light receiving element, the light receiving element is further divided into regions at a position away from the boundary line between the two regions by at least the radial length of a predetermined projected light spot diameter on the light receiving element. However, when the output signal is in focus, if there is an output above a certain level from an area outside this new boundary line, it means that a contrast pattern object that affects distance measurement accuracy is being measured. An automatic focus adjustment device that determines this and activates a warning device.