32 of the IC card 30.

To detect the position of the IC card 30 on the conveyance path 40, four sensors PD1, PD2, PD3, and PDi are provided along the conveyance path 40. The sensor PD1 is provided at a position on the near side of the conveyance path 40, and the position corresponds to the magnetic stripe 31 of the IC card 30. In the illustrated example, when considered along the conveyance direction of the IC card 30, the sensor PD1 is provided slightly on the far side of the position of the driving roller 51a. The sensor PD 3 is provided at a position on the far side of the conveyance path 40, and the position corresponds to the magnetic stripe 31 of the IC card 30. In the illustrated example, when considered along the conveyance direction of the IC card 30, the sensor PD3 is located approximately at the position of the driving roller 53a. The sensor PD2 is provided at a position approximately midway between the sensors PD1 and PD3. The magnetic head 46 is provided at such a position, and thus, it is not possible to provide the sensor PD2 at the position corresponding to a position of the magnetic stripe 31 of the IC card 30, and as a result, the sensor PD2 is provided at a position shifted toward a center in the width direction of the IC card 30. In the illustrated example, when considered along the conveyance direction of the IC card 30, the sensor PD2 is located approximately at the position of the driving roller 52a. The sensor PDi is provided slightly on the near side from the sensor PD2. Even such a position interferes with the magnetic head 46, and thus, the sensor PDi is provided at a position shifted toward the center in the width direction of the IC card 30 from the position corresponding to the magnetic stripe 31 of the IC card 30. When the position of the IC card 30 within the conveyance path 40, the position at which the communication terminal 32 is brought into electrical contact with the IC contact block 47, is defined as the communication position, the sensor PDi is disposed to detect the front end of the IC card 30 by the sensor PDi when the IC card 30 is at the communication position. A distance D between the sensor PDi and the sensor PD1 along the conveyance direction of the IC card 30 is shorter than a length L of the IC card 30, that is, a distance between the front end and the rear end of the IC card 30. The sensors PD1, PD2, PD3, and PDi are configured by an optical sensor capable of detecting the IC card 30 when a light path is blocked by the IC card 30.

Power transmission members that transmit a driving force of the motor 60 to the driving rollers 51a, 52a, and 53a include toothed belts 71 and 72. An output of the motor 60 is first transmitted to a large diameter gear portion 56b, which is a gear portion provided on a shaft body 56 supporting the driving roller 52a, via a gear 61 attached to a rotation shaft of the motor 60 and the toothed belt 71. The shaft body 56 is provided also with a small diameter gear portion 56a, which is a gear portion having a smaller diameter than the large diameter gear portion 56b, and the small diameter gear portion 56a rotates in conjunction with a rotation of the large diameter gear portion 56b. The shaft body 55 supporting the driving roller 51a and a shaft body 57 supporting the driving roller 53a are provided with gear portions 55a and 57a, respectively. The small diameter gear portion 56a of the shaft body 56 of the driving roller 52a and the gear portions 55a and 57a of the shaft bodies 55 and 57 of the driving roller 51a and the driving roller 53a are connected by the toothed belt 72, and rotate in conjunction with each other. Tensioners 74 and 75 of the toothed belt 72 are arranged before and after the driving roller 52a, and as a result, a constant tension is applied to the toothed belt 72. After all, in the card reader 10, the driving rollers 51a, 52a, and 53a are all driven by the single motor 60. Here, there are three sets of combination of the conveyance rollers, that is, the driving roller and the driven roller, provided in the card reader 10, however, the number of conveyance rollers is not limited to three sets, and there may be two sets or less or four sets or more. It is noted that the driven rollers 51b, 52b, and 53b on the bottom surface side of the conveyance path 40 are hidden by the driving rollers 51a, 52a, and 53a on the top surface side of the conveyance path 40, and thus, the driven rollers 51b, 52b, and 53b are not illustrated in FIG. 1B.

FIG. 2 is a block diagram illustrating a functional configuration of the card reader 10 serving as an electronic device. A control unit 20 that controls an overall operation of the card reader 10 is provided, and the control unit 20 is capable of communicating with the higher-level device 15 such as an ATM in which the card reader 10 is mounted. The control unit 20 is configured, for example, by a microcomputer or a microprocessor, and operates according to a software. The sensors PD1, PD2, PD3, and PDi, the magnetic head 46, and the IC contact block 47 are also connected to the control unit 20. Configuration is such that the IC contact block 47 is normally located above the conveyance path 40, but is pushed toward the conveyance path 40 side by a solenoid (not illustrated) controlled by the control unit 20, and is electrically contacted with the communication terminal 32 of the IC card 30 to perform a communication via the communication terminal 32. The motor 60 is provided with an encoder 62 connected to a rotation shaft of the motor 60, and a rotational position of the motor 60 can be detected by the encoder 62. The motor 60 is a direct current (DC) motor, and is controlled by the control unit 20 via a drive circuit 21. The control unit 20 outputs a position command and a current command (or a torque command) for the motor 60 to the drive circuit 21, and the drive circuit 21 drives the motor 60 by a servo control, based on the command from the control unit 20. For the servo control, rotational position information of the motor 60 is input from the encoder 62 to the drive circuit 21. The rotational position information of the motor 60 is also input to the control unit 20 from the encoder 62.

In such a card reader 10, the control unit 20 controls the drive of the motor 60 in response to the command from the higher-level device 15 to load and eject the IC card 30 into the card reader 10, and also reads and writes data from and to the card IC 30 located on the conveyance path 40. When the magnetic head 46 reads and writes data from and to the magnetic stripe 31 of the IC card 30