Abstract: In an information transmitting device, a variable capacitor which is charged to have a predetermined voltage discharges through a predetermined resistor. Until the voltage becomes lower than a predetermined threshold voltage, the number of AC signals having a predetermined frequency is counted. Accordingly, first continuous amount information of a binary code corresponding to a writing pressure is obtained and is converted to a Gray code, which is regarded as second continuous amount information. A resonant circuit is opened or shorted in accordance with ‘0’ or ‘1’ in the second continuous amount information, so as to transmit the second continuous amount information.

Abstract: In an information transmitting device, a variable capacitor which is charged to have a predetermined voltage discharges through a predetermined resistor. Until the voltage becomes lower than a predetermined threshold voltage, the number of AC signals having a predetermined frequency is counted. Accordingly, first continuous amount information of a binary code corresponding to a writing pressure is obtained and is converted to a Gray code, which is regarded as second continuous amount information. A resonant circuit is opened or shorted in accordance with ‘0’ or ‘1’ in the second continuous amount information, so as to transmit the second continuous amount information.

Abstract: In an information transmitting device, a variable capacitor which is charged to have a predetermined voltage discharges through a predetermined resistor. Until the voltage becomes lower than a predetermined threshold voltage, the number of AC signals having a predetermined frequency is counted. Accordingly, first continuous amount information of a binary code corresponding to a writing pressure is obtained and is converted to a Gray code, which is regarded as second continuous amount information. A resonant circuit is opened or shorted in accordance with ‘0’ or ‘1’ in the second continuous amount information, so as to transmit the second continuous amount information.

Abstract: A position input device is provided in which signals are transmitted from a position indicator, and signals transmitted from the position indicator are received by a position detector device. According to certain embodiments, an electrical double-layer capacitor, a charging circuit which charges the electrical double-layer capacitor, and a power transmission unit which relays and supplies to the charging circuit power supplied from a power supply unit external to the position indicator, are provided in the position indicator. In other embodiments the position input device has a built-in power supply unit, transmitting units, and a control unit for switching the transmitting units between energized and de-energized states. Also provided are position input systems and computer systems including the position input device, and methods of operating the position input device and the systems.

Abstract: In an information transmitting device, a variable capacitor which is charged to have a predetermined voltage discharges through a predetermined resistor. Until the voltage becomes lower than a predetermined threshold voltage, the number of AC signals having a predetermined frequency is counted. Accordingly, first continuous amount information of a binary code corresponding to a writing pressure is obtained and is converted to a Gray code, which is regarded as second continuous amount information. A resonant circuit is opened or shorted in accordance with ‘0’ or ‘1’ in the second continuous amount information, so as to transmit the second continuous amount information.

Abstract: A position indicator includes a time-constant circuit having an element whose characteristic continuously varies in response to operation represented as a continuous quantity such as writing force, and capable of switching the variation range of time constant in response to the variation in characteristic of the element in at least two ways; and a discharging/charging device capable of discharging the time-constant circuit from a predetermined voltage to a voltage below a specified voltage, or charging the time-constant circuit from the predetermined voltage to a voltage exceeding the specified voltage. Using the time-constant circuit and discharging/charging device, the number of waves of AC signals at a specified frequency is counted from the discharge start time to the time when the voltage falls below the specified voltage, or from the charge start time to the time when the voltage exceeds the specified voltage, by switching the variation range of time constant.

Abstract: In an information transmitting device, a variable capacitor which is charged to have a predetermined voltage discharges through a predetermined resistor. Until the voltage becomes lower than a predetermined threshold voltage, the number of AC signals having a predetermined frequency is counted. Accordingly, first continuous amount information of a binary code corresponding to a writing pressure is obtained and is converted to a Gray code, which is regarded as second continuous amount information. A resonant circuit is opened or shorted in accordance with ‘0’ or ‘1’ in the second continuous amount information, so as to transmit the second continuous amount information.

Abstract: A position indicator includes a time-constant circuit having an element whose characteristic continuously varies in response to operation represented as a continuous quantity such as writing force, and capable of switching the variation range of time constant in response to the variation in characteristic of the element in at least two ways; and a discharging/charging device capable of discharging the time-constant circuit from a predetermined voltage to a voltage below a specified voltage, or charging the time-constant circuit from the predetermined voltage to a voltage exceeding the specified voltage. Using the time-constant circuit and discharging/charging device, the number of waves of AC signals at a specified frequency is counted from the discharge start time to the time when the voltage falls below the specified voltage, or from the charge start time to the time when the voltage exceeds the specified voltage, by switching the variation range of time constant.

Abstract: An optical system for variable inclination angle microscope tubes, in order to shorten properly the distance between the position of the eye point and focusing handle thereby to improve the operability, comprising a first optical element for bending at right angles the light path of the incident light, a second optical element for bending twice at right angles the light path of the incident light from the first optical element, a third optical element for bending twice at right angles the light path of the incident light from the second optical element and a fourth optical element arranged to bend at right angles the light path of the incident light from the third optical element and then direct it in the same direction as of the incident light upon the first optical element, the third optical element being mounted rotatably around the optical axis of the incident light upon it and the fourth optical element being so mounted as to be able to rotate by an angle twice as large as the angle of rotation of the th

Abstract: An optical system for retinal cameras wherein the distance between an eye to be inspected and an inspector is made short to improve the operatability and to make it easy to handle the eye to be inspected.

Abstract: An image forming lens system comprising a front lens group having a positive refractive power and consisting of a positive lens component and a negative lens component or consisting of a positive lens component and a cemented lens component consisting of a positive lens element and a negative lens element cemented with each other, and a rear lens group having a negative refractive power and being a single lens component or a cemented lens component consisting of a negative lens element and a positive lens element cemented with each other or consisting of a negative lens element and a positive lens element separated from each other. The entire lens system has a positive power and satisfies the conditions necessary for a microscopic objective and can relay an image without impairing the image performance of the objective.

Abstract: A compactly designable optical system for ophthalmological instruments comprising an illumination system so adapted as to illuminate a fundus with rays having passed through a ring slit and been focused on the cornea of an eyeball to be examined, and an observation/photographing system so adapted as to permit observing and photographing an image of said eyeball with a small reflector mirror arranged in said illumination system so as to be inclined with regard to the optical axis thereof and a relay lens for focusing the rays which are reflected by the fundus, passing through said objective lens and reflected by said small reflector mirror.

Abstract: The present invention relates to an ocular comprising a first lens component of a positive single or cemented lens, a second lens component of a positive single lens, a third lens component of a biconcave lens and a fourth lens component of a positive single lens. The ocular is constituted of a triplet type lens system comprising as a basis the second through fourth lens components and, in addition, the positive single or cemented lens.

Abstract: A compact zoom lens system with high zooming ratio for which the range of focal length is 16 to 192, i.e., the zooming ratio is 1:12, and aperture ratio is large and which comprises a focusing lens group having positive power, a variator lens group having negative power, a compensator lens group having negative power, an erector lens group having positive power and a master lens group.

Abstract: An enlarging lens system comprising a first lens component which is a positive meniscus lens, a second lens component which comprises a positive meniscus lens and negative meniscus lens, a third and fourth lens components which are respectively positive meniscus lenses, a fifth lens component which comprises a negative meniscus lens and positive meniscus lens, and a sixth lens component which is a positive meniscus lens. Said enlarging lens system is characterized in that thin lenses having weak refractive powers are used as the third and fourth lens components, the aperture ratio is large and aberrations are favorably corrected.

Abstract: A large-aperture enlarging lens system which comprises a first positive meniscus lens component, a second positive meniscus lens component, a third lens component consisting of two lens elements, a fourth lens component consisting of two lens elements and a fifth positive lens component, either one of said third and fourth lens components arranged on both sides of a stop having a convex lens on the side of said stop, and wherein aberrations are favorably corrected.

Abstract: A high magnification microscope objective having a very large numerical aperture which comprises a first positive lens component, a second positive lens component, a third cemented lens component having positive refractive power, a fourth positive lens component and a fifth cemented lens component, and wherein chromatic aberration, curvature of field, etc. are favorably corrected.

Abstract: An enlarging lens system comprising a front lens group which comprises a first, second, third and fourth lens components and a rear lens group which comprises a fifth, sixth and seventh lens components in which the first and second lens components are positive meniscus lenses, the third lens component is a positive meniscus lens consisting of a single lens or cemented doublet lens, the fourth lens component is a negative meniscus lens consisting of a single lens or cemented doublet lens, the fifth lens component is a negative meniscus lens consisting of a single lens or cemented doublet lens, and the sixth and seventh lens components are positive meniscus lenses, said enlarging lens system satisfying the following conditions. ##EQU1## Said enlarging lens system has the aperture ratio of F/3.5 and field angle of 50.degree. and is arranged so that at image of good quality can be obtained over the whole field.