Abstract: Provided is an angle detection apparatus making it possible to reduce the labor of manufacturing while also suppressing bulkiness. The angle detection apparatus includes a first rotating body (120), a second rotating body (122), a first transmission mechanism (111) that causes the second rotating body (122) to rotate by reducing a speed of a rotation of the first rotating body (120), a first angle detector (Ds) that detects a rotational angle of the first rotating body (120), another second angle detector (Dm) that detects a rotational angle of the second rotating body (122), and a processor (40) that specifies a number of revolutions (Rs) of the first rotating body (120).

Abstract: An absolute encoder preferable in being made compact is provided. The absolute encoder includes a worm gear, a permanent magnet (19) provided on a top end side of the worm gear, and magnetic sensors. In the permanent magnet (19), a given first polar portion (N) among first polar portions each having a first polarity and a given second polar portion (S) among second polar portions each having a second polarity different from the first polarity are formed adjacent to each other, when viewed from an end surface of the permanent magnet (19) in an axial direction thereof. A given first polar portion (N) and a given second polar portion (S) are formed to be adjacent in a radial direction, with a radial middle portion of the permanent magnet (19) that is a boundary. A given first polar portion (N) and a given second polar portion (S) are formed to be adjacent in an axial direction, with an axial middle portion of the permanent magnet (19) that is a boundary.

Abstract: Provided is an angle detection apparatus making it possible to reduce the labor of manufacturing while also suppressing bulkiness. The angle detection apparatus includes a first rotating body (120), a second rotating body (122), a first transmission mechanism (111) that causes the second rotating body (122) to rotate by reducing a speed of a rotation of the first rotating body (120), a first angle detector (Ds) that detects a rotational angle of the first rotating body (120), another second angle detector (Dm) that detects a rotational angle of the second rotating body (122), and a processor (40) that specifies a number of revolutions (Rs) of the first rotating body (120).

Abstract: A simply structured apparatus according to the present invention corrects an overdrive power level. A main controller allows an overdrive power generator to set an overdrive power current to zero, allows a base power controller to control a base power current with the target value of a base power monitor level set to a desired overdrive power level. When the base power monitor level has reached the target value, the main controller allows said overdrive power generator to increase the overdrive power current until a base power control signal monitored by a base power control signal monitor reaches a value corresponding to a desired base power level.

Abstract: A simply structured apparatus according to the present invention corrects an overdrive power level. A main controller allows an overdrive power generator to set an overdrive power current to zero, allows a base power controller to control a base power current with the target value of a base power monitor level set to a desired overdrive power level. When the base power monitor level has reached the target value, the main controller allows said overdrive power generator to increase the overdrive power current until a base power control signal monitored by a base power control signal monitor reaches a value corresponding to a desired base power level.

Abstract: The delay time of a variable delay circuit is set to a desired value by: sequentially applying a plurality of clocks of different frequencies to a variable delay circuit; finding, for each clock, the amount of change in delay time with respect to change in a delay time selection signal, which is a signal for setting the delay time of the variable delay circuit; finding a linear coefficient of the characteristic of the delay time of the variable delay circuit with respect to the delay time selection signal from the difference in the amounts of change with respect to the difference in clock frequencies; finding an amount of offset with respect to the delay time selection signal that pertains to the variable delay circuit from the amounts of change and frequencies of the clocks; and finding the delay time selection signal from the linear coefficient and the difference between the desired delay time and the offset amount.

Abstract: An optical disk apparatus having an optical head for reading and writing signals on an optical disk and a signal processing unit for performing predetermined signal processing on the signals is disclosed. The apparatus includes a first controller, a second controller, a detector, and an adjuster. The first controller controls the optical head to write a predetermined signal on a predetermined area of the optical disk with various levels of recording power of the optical head. The second controller reproduces the predetermined signal written on the predetermined area of the optical disk. The detector attempts to detect a predetermined signal pattern having a predetermined period from the reproduced signal with different slice levels. The adjuster determines a resolution of the reproduced signal in accordance with a slice level with which the signal pattern can be detected and automatically adjusts the recording power of the optical head based on the determined resolution.