JPS5984963U - automatic focus device - Google Patents

Abstract

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

Description

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of the photographing optical system. FIG. 2 is a front view of the image pickup tube. FIG. 3 is a block diagram of the control circuit. FIG. 4 is a block diagram of the sensitivity switching circuit. Figure 5'' is a waveform diagram of the vertical blanking signal. FIG. 6 is a diagram showing the scanning state in the sensor section of the image pickup tube after switching the focus detection speed using a waveform diagram of a vertical blanking signal. Figure 7, Figure 8,
FIG. 9 is a timing chart diagram of signal waveforms of each circuit for explaining the operating state of the sensitivity switching circuit. FIG. 10 is an explanatory diagram for explaining the relationship between the vertical synchronizing signal of the synchronizing signal generating circuit and the output signal of the frequency dividing circuit. Figure 11- is
FIG. 7 is a diagram showing a scanning state in a sensor unit and a waveform diagram of a vertical blanking signal in another configuration example of a sensitivity switching circuit. FIG. 12 is a diagram showing the configuration of the output waveform of the frequency dividing circuit in the case shown in FIG. 11. DESCRIPTION OF SYMBOLS 1... Image pickup tube, 3... Imaging lens system, 6... Video screen, 9... Movable lens group, 10... Pulse smoke (image forming and lens driving means), 11...・Output pinion (
imaging lens driving means), 12... rack (imaging lens driving means), 13... beam splitter (spectroscopic means)
, 16...Sensor lens group, 18...Sensor section (
Focus (detection means), 19... Pulse motor (sensor lens drive means), 20... Output pinion (sensor lens drive means), 21... Rack (sensor lens drive means), 28... Counter circuit (sensor lens position detection means), 30... counter circuit (imaging lens position detection means), 34... focus detection circuit (focus detection means), 36... comparison circuit (focus i movement direction determining means).

Claims (1)

[Scope of Claim for Utility Model Registration] An imaging lens that forms an image of photographic light from an object to be photographed onto a video screen of the photocathode of an image pickup tube, and the imaging lens is positioned at a close distance to the object to be photographed on its front axis. an imaging lens driving means that reciprocates between a focus position and an infinity focus position; and - detects focus on a photocathode other than the image screen of the image pickup tube by splitting a part of the photographing light. a spectroscopic means for guiding the light for use; a sensor lens for detecting a good focus, which is provided so as to be reciprocally movable between the spectrometer and the image pickup tube; A sensor lens driving means that reciprocates to the focal position; 1. 2) Focus detection means for detecting focus by forming an image of the focus detection light on a photocathode and outputting a focus detection signal; and based on the focus detection signal. sensor lens position detection means for detecting the position of the sensor lens and outputting the sensor lens position detection signal; and imaging lens position detection means for detecting the position of the imaging lens and outputting the imaging lens position detection signal. means for detecting a moving direction amount of the imaging lens based on the sensor lens position detection signal and the imaging lens position detection signal, and outputting the detection signal so that the imaging lens driving means is driven. An automatic focusing device comprising: a focusing movement direction amount determining means; and an automatic focusing device.