Abstract: The objective of the present invention is to provide a contact lens solution that is safer to eyes such that it has little or no effects on eye tissue and has the versatility that makes the solution applicable to a wide range of contact lenses, while exhibiting desirable anti-Acanthamoeba activity. The objective is achieved by the anti-Acanthamoeba contact lens solution containing a cationic polymer having an average molecular weight in a range of 150,000 to 1,600,000 and having in its molecule a diallyldimethylammonium chloride unit and an inorganic salt.

Abstract: The objective of the present invention is to provide a contact lens solution that is safer to eyes such that it has little or no effects on eye tissue and has the versatility that makes the solution applicable to a wide range of contact lenses, while exhibiting desirable anti-Acanthamoeba activity. The objective is achieved by the anti-Acanthamoeba contact lens solution containing a cationic polymer having an average molecular weight in a range of 150,000 to 1,600,000 and having in its molecule a diallyldimethylammonium chloride unit and an inorganic salt.

Abstract: A digital-to-analog converting circuit includes first and second potential terminals, an output node, first and second resistors, first and second switches and a control circuit. The first resistors are connected in series between a first node and the output node through first connecting points. Each of the first switches is connected between the first potential terminal and one of the first connecting points and the first node. The second resistors are connected in series between a second node and the output node through second connecting points. Each of the second switches is connected between the second potential terminal and one of the second connecting points and the second node. The control circuit controls the first and second switches.

Abstract: A start signal (STA) at “H” causes a current to flow through a constant-current portion (10) and control voltages to be produced at nodes (N1, N2) for biasing of a reference voltage portion (20) and an output portion (30), respectively. This allows a predetermined current to flow through the reference voltage portion (20), and a reference voltage (VRF) to be output at a node (N4). With the start signal (STA) at “L”, only a constant-voltage device (22) provides a reference voltage (VRF1), whereas the start signal (STA) at “H” causes the constant-voltage devices (22,23) to be connected in parallel to provide a reference voltage (VRF2). The reference voltage (VRF) is amplified at an output portion having a differential amplifier arranged in the voltage follower connection to output an internal voltage (VOUT) corresponding to the reference voltage (VRF).

Abstract: A digital-to-analog converting circuit includes first and second potential terminals, an output node, first and second resisters, first and second switches and control circuit. The first resisters are connected in series between a first node and the output node through first connecting points. Each of the first switches is connected between the first potential terminal and one of the first connecting points and the first node. The second resisters are connected in series between a second node and the output node through second connecting points. Each of the second switches is connected between the second potential terminal and one of the second connecting points and the second node. The control circuit controls the first and second switches.

Abstract: A start signal (STA) at “H” causes a current to flow through a constant-current portion (10) and control voltages to be produced at nodes (N1, N2) for biasing of a reference voltage portion (20) and an output portion (30), respectively. This allows a predetermined current to flow through the reference voltage portion (20), and a reference voltage (VRF) to be output at a node (N4). With the start signal (STA) at “L”, only a constant-voltage device (22) provides a reference voltage (VRF1), whereas the start signal (STA) at “H” causes the constant-voltage devices (22,23) to be connected in parallel to provide a reference voltage (VRF2). The reference voltage (VRF) is amplified at an output portion having a differential amplifier arranged in the voltage follower connection to output an internal voltage (VOUT) corresponding to the reference voltage (VRF).