An image reading apparatus of the invention is designed to read an image on a manuscript. The manuscript may be located under or above the image reading apparatus. The image reading apparatus comprises a casing, a reading mechanism situated inside the casing, an actuating mechanism situated inside the casing for moving the reading mechanism, and a circuit mechanism for controlling the reading mechanism and the actuating mechanism. The casing has a reading window formed inside an upper or bottom portion of the casing. An image to be read is placed adjacent to the reading window, and the reading mechanism reads the image through the reading window. The circuit mechanism is provided with at least one circuit plate, which is located at one side of the casing above or below a moving area of the reading mechanism. Accordingly, the size of the image reading apparatus is minimized. A grip is integrally formed with the casing, and the circuit plate is retained inside the grip.

The invention relates to a method and to an arrangement for the synchronization of the image recording of monochrome recordings and color recordings with photosensitive line sensors. A line-scanning pattern is generated by a programmable counter arrangement, wherein the timer measures the phase position of the line-scanning pattern, generated by the counter arrangement, with the aid of the computer and the programmable counter arrangement at the point in time of the impinging of a pulse of the incremental transmitter, wherein the timer compares these with a coordinated calculated or tabulated reference value, and wherein the timer employs the thus obtained phase difference in order to influence a counter, preconnected to the line counter CT2, in its count volume (FIGS. 1 and 2). The timer splits the measurement lines of the image recording device into two or more scanning lines if the integration time of the photosensitive lines within the measurement line results in an exposure higher than the operating limit of the sensors.

A motion of a printed circuit board (1) is detected by an encoder (4) arranged aside a belt conveyer (2), and the encoder generates a detection signal (S3) which activates a timing signal generator unit (5) for generating an image pickup start timing signal which is fed to a time measuring unit (6) for measuring the image storing time which corresponds to the time interval of the image pickup start signal (S1). According to the image storing time, the image signal (S2) generated by the line CCD camera (3) is normalized by the normalizing calculation means (7), and thereafter, the mounting condition of the printed circuit board is judged by the image recognizing section (B) with the use of the image data (D) to thereby realize a simple and convenient mechanism at a low cost and at a high precision.

A motion of a printed circuit board (1) is detected by an encoder (4) arranged aside a belt conveyer (2), and the encoder generates a detection signal (S.sub.3) which activates a timing signal generator unit (5) for generating an image pickup start timing signal which is fed to a time measuring unit (6) for measuring the image storing time which corresponds to the time interval of the image pickup start signal (S1). According to the image storing time, the image signal (S2) generated by the line CCD camera (3) is normalized by the normalizing calculation means (7), and thereafter, the mounting condition of the printed circuit board is judged by the image recognizing section (B) with the use of the image data (D) to thereby realize a simple and convenient mechanism at a low cost and at a high precision.

An image scanner for reading an image data or an image scanning method using the same, wherein the image scanner includes a control circuit obtaining correction data to maintain normal continuity for the image data, by weighting or averaging a plurality of image data when a drive motor for a carrier including a reading head, is decelerating or accelerating, in the case when the reading restarts after the reading operation has been interrupted.