JPS6277968U - - Google Patents

Description

[Brief explanation of the drawing]

1 to 5 relate to an embodiment of the present invention,
Figure 1 is an overall circuit block diagram, Figure 2 is a schematic explanatory diagram of the display pattern in the electronic viewfinder,
FIG. 3 is a circuit diagram of the main parts of the vertical comparison circuit and the vertical expansion circuit, FIG. 4 is a circuit diagram of the main parts of the display signal multiplexing circuit, and FIG. 5 is a circuit diagram of the main parts of the preset circuit and the vertical and horizontal registers. Further, FIG. 6 is an explanatory diagram of a sampling area in a conventional example, and FIG. 7 is a diagram of the relationship between lens position and focus value. 40...Selection control circuit, 50...Detection circuit.

Claims (1)

[Scope of utility model registration request] A vertical counter that uses the vertical synchronization signal as a reset input and counts the frequency-divided output of the horizontal synchronization signal, a vertical register that stores the vertical position of the sampling area, and a vertical comparison that detects coincidence between the outputs of the vertical counter and the vertical register. A circuit, a horizontal counter that receives a horizontal synchronization signal as a reset input and counts the multiplied output of the horizontal synchronization signal, a horizontal register that stores the horizontal position of a sampling area, and detects coincidence between each output of the horizontal counter and the horizontal register. a horizontal comparison circuit, a reference sampling pulse generation circuit which uses the AND output of the outputs of the two comparison circuits as a reference sampling pulse, a sampling area selection circuit which sets arbitrary values in the vertical and horizontal registers, and an output of the vertical comparison circuit. a horizontal expansion circuit that expands the output of the horizontal comparison circuit; an expansion sampling pulse generation circuit that uses the logical AND output of both expansion circuits as an expansion sampling pulse; and the reference sampling pulse or the expansion circuit. A sampling circuit that samples high-frequency components in a video signal using a sampling pulse, a focus control circuit that rotates a focus ring so that the sampling output is maximized, and selectively selects the reference sampling pulse and the extended sampling pulse. and a sampling pulse selection circuit for supplying the sampling pulse to the sampling circuit, the circuit includes a detection circuit for detecting a change in the output of the sampling area selection circuit; A sampling area changing circuit comprising a selection control circuit that causes the sampling pulse selection circuit that had selected a pulse to select the reference sampling pulse for a certain period of time and then selects the extended sampling area again.