Abstract: When information is received specifying a desired product and a desired light source type, e.g. a type of a light source used in an environment in which the product, if purchased, would actually be used, a server device provides a color reproducing correction process for original image data obtained by shooting the desired product. Specifically, component data corresponding to a color of the light source at shooting and that corresponding to a color of the light source of the desired type are used to correct original image data to attain image data obtained when the product is shot under the desired light source type. The data obtained by the correction is transmitted to a consumer terminal and displayed on a screen. The consumer confirms the displayed image, and if satisfied with e.g. how the product would present color, the process moves on to an on-line transaction process for product purchasing.

Abstract: When information is received specifying a desired product and a desired light source type, e.g. a type of a light source used in an environment in which the product, if purchased, would actually be used, a server device provides a color reproducing correction process for original image data obtained by shooting the desired product. Specifically, component data corresponding to a color of the light source at shooting and that corresponding to a color of the light source of the desired type are used to correct original image data to attain image data obtained when the product is shot under the desired light source type. The data obtained by the correction is transmitted to a consumer terminal and displayed on a screen. The consumer confirms the displayed image, and if satisfied with e.g. how the product would present color, the process moves on to an on-line transaction process for product purchasing.

Abstract: At the input sides of matched first and second differential amplifiers 11 and 12, first and second input buffers 21 and 22, and third and fourth input buffers 23 and 24 are respectively connected. In input transistors Q5 and Q8 in the first and second input buffers 21 and 22, emitter currents corresponding to the collector currents of differential transistors Q3 and Q4 of the second differential amplifier 12 flow by using current mirror circuits. Changes of base-emitter voltage of the PNP transistors Q5 and Q8, and changes of base-emitter voltage of NPN transistors Q1 and Q2 cancel each other, and an output voltage improved in linearity is obtained between a negative phase output terminal 33 and a positive phase output terminal 34.

Abstract: A multiplier circuit including a first voltage supply for supplying a first voltage; a second voltage supply for supplying a second voltage; and a control section having a first terminal through which an input current flows, a second terminal through which a current equal to or a constant multiple of the input current at the first terminal flows, the first voltage being supplied to the second terminal, a third terminal through which an output current flows, and a fourth terminal through which a current equal to or a constant multiple of the output current at the third terminal. The second voltage is applied to the fourth terminal. The control section controls the output current so that a logarithm of a ratio of an absolute value of the output current to an absolute value of the input current is in proportion to a difference between the first voltage and the second voltage.

Abstract: An apparatus for driving a semiconductor laser device wherein the optical output of the laser device is maintained at a predetermined level by a feedback control. The apparatus includes at least two D/A converters. One of the D/A converters is used for conducting a coarse adjustment of the optical output level, and another of the D/A converters is used for conducting a fine adjustment of the optical output level.