JPH0275516U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a lens barrel having a magnetic encoder device according to the present invention, FIG. 2 is a block system diagram of a USM drive circuit in which the magnetic encoder device according to the present invention is used, and FIG. , a detailed electric circuit diagram of the magnetic encoder processing circuit in FIG. Figures 5A and 5B are layout diagrams of the magnetization patterns showing cases in which the magnetic pole distribution narrows smoothly from the center to the end of the movement, and B shows the case in which it narrows suddenly. Figures 6A, B, and C are diagrams showing the USM rotational speed corresponding to the magnetic patterns, and waveform diagrams showing pulse trains output from the M/M 63 in the USM drive circuit. If distributed at intervals, B has the magnetization pattern shown in FIG. 4A,
C is a waveform diagram corresponding to the magnetization pattern shown in FIG. 4B, FIG. 7 is a block system diagram showing an example of speed control using a conventional magnetic encoder device, and FIG. FIG. 9 is a circuit diagram of the magnetoresistive transducer that constitutes the element, FIG. 9 is a diagram of the magnetization pattern of the magnetic encoder device and its output waveform, and FIG. 10 is an explanation of the lens drive range in the lens barrel using the conventional magnetic encoder device. FIG. 4 is a layout diagram of main parts of a magnetization pattern and a cam groove. 3... Moving member, 7... Fixed member, 10... Magnetized pattern, 12... Magnetoresistive conversion element, 70...
...control circuit.

Claims (1)

[Claims for Utility Model Registration] A fixed member, a movable member that is moved relative to the fixed member by a drive source such as a motor, and a movable member that is moved relative to the fixed member on a surface of the movable member that faces the fixed member. A magnetized pattern magnetized along the movement locus of the member, a magnetoresistive conversion element provided at a position on the fixed member facing the magnetized pattern, and an output of this magnetoresistive conversion element to cause the movement. A control circuit that controls the moving speed of the member, and a magnetic encoder device comprising: a control circuit that controls a moving speed of the moving member, and a distance between the magnetic patterns facing the magnetoresistive converting element near the end of movement of the moving member at other positions; A magnetic encoder device characterized by being narrower than the above.