Abstract: In an autofocus image sensor, monitoring pixels are disposed adjacent to a pixel array over a length equal to that of the pixel array in each of a standard portion and a reference portion. Signals from the monitoring pixels of both of the standard portion and the reference portion are subjected to arithmetic operation to control accumulation of electric charges. Thus, an error in position detection is minimized.

Abstract: A focus detection device having a pair of light receiving sections (a first and second light receiving sections) which receive subject images observed from different view fields having parallax to accumulate charges is disclosed. The accumulation of the charges in the pair of light receiving sections is ended selectably based on an accumulation level of the charges at one light receiving section and an accumulation levels of the charges at both light receiving sections. Moreover/alternatively, the light receiving section has a plurality of light receiving units, and signals to end the accumulation of the charges at the respective light receiving units are sent to the first and second light receiving sections. In this case, a combination of the light receiving unit of the first light receiving section and the light receiving unit of the second light receiving section to which the signals are to be sent can be switched.

Abstract: There is disclosed a focus detection device having a light receiving section in which charges are generated and accumulated based on quantities of received lights and a charge accumulating section in which the charges accumulated in the light receiving section are transferred and accumulated. The focus detection device starts the accumulation of the charge in the light receiving section, when the charge accumulating section retains a reset state, and the device cancels the reset state of the charge accumulating section at a predetermined timing before the charges accumulated in the light receiving section are transferred to the accumulating section Moreover/alternatively, a focus detection device using a plurality of photo sensors is disclosed. A phase of a reading signal of a part of the photo sensors is different from that of a reading signal of another part.

Abstract: The present invention discloses a focus detection device capable of reading a plurality of focus detection outputs in parallel. As an exemplary structure, the focus detection device includes a focus detection sensor having a plurality of output terminals for outputting, in parallel, analog data corresponding to focus states of multiple points in the field of a viewfinder, a multiplexer for arranging and outputting, in chronological order, the analog data output in parallel from the plurality of output terminals of the focus detection sensor, and an A/D converter for converting, to digital data, the analog data arranged in chronological order through and output from the multiplexer.

Abstract: A variable resistance circuit and application circuits using the same capable of offsetting the variance in the manufacture of integrated circuit and the influence of ambient temperatures, including: a control circuit having a plurality of constant-current output terminals, with a constant current ratio of the output terminals varied by signals applied to a control terminal; an operational amplifier; a resistor; and a plurality of MOS transistors having the gates thereof connected in common; and one output terminal of the control circuit being connected to one end of the resistor and to an inverted input terminal of the operational amplifier and the other output terminal being connected to the drain of one MOS transistor connected at the gate thereof to an output terminal of the operational amplifier and being connected to a non-inverted input terminal of the operational amplifier; and the other end of said resistor and the source of said one MOS transistor being connected to a reference voltage terminal.

Abstract: A variable resistance circuit and application circuits using the same capable of offsetting the variance in the manufacture of integrated circuit and the influence of ambient temperatures, including: a control circuit having a plurality of constant-current output terminals, with a constant current ratio of the output terminals varied by signals applied to a control terminal; an operational amplifier; a resistor; and a plurality of MOS transistors having the gates thereof connected in common; and one output terminal of the control circuit being connected to one end of the resistor and to an inverted input terminal of the operational amplifier and the other output terminal being connected to the drain of one MOS transistor connected at the gate thereof to an output terminal of the operational amplifier and being connected to a non-inverted input terminal of the operational amplifier; and the other end of said resistor and the source of said one MOS transistor being connected to a reference voltage terminal.

Abstract: A period extracting section extracts a specific period in a dot code in an image signal corresponding to the dot code, and this specific period is supplied field by field to a maximum value detection section and a minimum value detection section via a detection gate. A threshold value detection section computes the binary threshold value from the detected field-by-field maximum value and minimum value, and holds it in a data holding section. A comparator compares the held threshold value with an image signal with the dot period emphasized by a signal processor to thereby binarize the image signal corresponding to the dot code.

Abstract: A period extracting section extracts a specific period in a dot code in an image signal corresponding to the dot code, and this specific period is supplied field by field to a maximum value detection section and a minimum value detection section via a detection gate. A threshold value detection section computes the binary threshold value from the detected field-by-field maximum value and minimum value, and holds it in a data holding section. A comparator compares the held threshold value with an image signal with the dot period emphasized by a signal processor to thereby binarize the image signal corresponding to the dot code.

Abstract: A period extracting section extracts a specific period in a dot code in an image signal corresponding to the dot code, and this specific period is supplied field by field to a maximum value detection section and a minimum value detection section via a detection gate. A threshold value detection section computes the binary threshold value from the detected field-by-field maximum value and minimum value, and holds it in a data holding section. A comparator compares the held threshold value with an image signal with the dot period emphasized by a signal processor to thereby binarize the image signal corresponding to the dot code.