JPH0412435U - - Google Patents

Description

[Brief explanation of the drawing]

1 to 4 relate to an embodiment of the present invention, in which FIG. 1 is a block diagram showing the schematic configuration of a photosensitive material detection device, FIG. 2 is an operation waveform diagram of each part of the device, and FIG. An explanatory diagram of the main parts of an automatic developing machine in which a sonic switch is installed, and FIG. 4 is a schematic diagram of the configuration of an ultrasonic transmitting/receiving element. 1c...Film guide (background object), F...Photosensitive material, 10...Ultrasonic switch, 11...Ultrasonic transmitting/receiving element, {16...Spatial detection distance setting circuit, _G1 ...AND gate} Pulse signal extraction section, 17... Output section, 17a, 17b... Latch circuit.

Claims (1)

[Claims for Utility Model Registration] A photosensitive material detection device that detects the presence or absence of a photosensitive material being conveyed along a film guide using a reflection type ultrasonic switch, wherein the ultrasonic switch irradiates ultrasonic waves. A spatial detection signal having a pulse width within a range that includes the point in time when the reflected wave from the photosensitive material is received, but does not include the point in time when the reflected wave from the background object of the photosensitive material is received, is used as a logic gate. By controlling the
a pulse signal extraction unit that extracts a pulse signal based on the reflected wave from the photosensitive material from among the pulse signals obtained by receiving the reflected wave; and a pulse signal extraction unit that indicates the presence or absence of the photosensitive material based on the extracted pulse signal. A photosensitive material detection device comprising: an output section that outputs a detection signal;