Abstract: In press molding, a shaft (metal mold 13) is moved by positional or torque control to cause upper and lower molds to reach a set position slightly before a position where the upper and lower molds are set in a final mold closed state. As soon as the upper and lower molds reaches the set position, the control is switched to torque control using a small force which does not deform a glass material to perform feedback control. For this reason, when the cooling process is started, the mobile shaft is moved by the same amount as a contraction amount of the shaft, the actual position of the shaft is moved. However, a tight contact state between the molds and the glass material is kept without changing the thickness of the glass material, and positional control and torque control can be apparently performed at once. Thereafter, when temperature reaches an almost glass transition point, final pressing is performed.

Abstract: A method of manufacturing an optical waveguide comprises a first step of laminating, on one major surface of a first glass material, a second glass material to a desired thickness, the second glass material having optical characteristics different from those of the first glass material, a second step of forming the second glass material to have a desired circuit pattern, and a third step of laminating a third glass material having optical characteristics similar to those of the first glass material on an entire surface of the first glass material on which the circuit pattern is formed by the second glass material. In at least one of the first and third steps, the glass material to be laminated is laminated by coupling.

Abstract: In press molding, a shaft (metal mold 13) is moved by positional or torque control to cause upper and lower molds to reach a set position slightly before a position where the upper and lower molds are set in a final mold closed state. As soon as the upper and lower molds reaches the set position, the control is switched to torque control using a small force which does not deform a glass material to perform feedback control. For this reason, when the cooling process is started, the mobile shaft is moved by the same amount as a contraction amount of the shaft, the actual position of the shaft is moved. However, a tight contact state between the molds and the glass material is kept without changing the thickness of the glass material, and positional control and torque control can be apparently performed at once. Thereafter, when temperature reaches an almost glass transition point, final pressing is performed.

Abstract: A method and apparatus are disclosed which place a glass blank on a lower mold arranged in an opposed relation to an upper mold, heat these molds and glass blank by an infrared lamp unit or high-frequency coil arranged around the molds and press-mold an optical glass element. In the method and apparatus, the infrared lamp unit or high-frequency coil is supported by a supporting mechanism such that it is movable along a direction in which the mold is moved. In cases where a relative position of the infrared lamp unit or high-frequency coil to the mold varies depending upon the shape and size of such molds or the shape and size of optical glass elements obtained, the infrared lamp or high-frequency coil is adjustably moved relative to the mold by a movable mechanism using a motor or air cylinder as an operation source. By using temperature sensors attached to both the molds, the temperatures of the upper and lower molds are controlled to a corresponding desired level.

Abstract: The apparatus for molding an optical glass element is made up of relatively movable upper and lower molds for press molding a glass blank, and a plurality of infrared ray lamps encircling the upper and lower molds, temperature measuring devices for measuring the temperatures of the upper and lower molds, and a controller responsive to the outputs of the temperature measuring devices for controlling electric inputs to the infrared ray lamps thereby maintaining the temperatures of the upper and lower molds at predetermined values.

Abstract: The apparatus for molding an optical glass element is made up of relatively movable upper and lower molds for press molding a glass blank, and a plurality of infrared ray lamps encircling the upper and lower molds, temperature measuring devices for measuring the temperatures of the upper and lower molds, and a controller responsive to the outputs of the temperature measuring devices for controlling electric inputs to the infrared ray lamps thereby maintaining the temperatures of the upper and lower molds at predetermined values.