| 摘要 |
PURPOSE:To ensure that any density variation is always read accurately and also is corrected properly, if a medium for recording and recording parameters are changed by making variable a collimation value when the density pattern of a test pattern is read depending on a recording medium. CONSTITUTION:To correct the density variation of data recorded by a recording head 1001, a density variation reading device 1014 is provided which reads a test pattern formed on a media for recording 1002 by the recording head 1001. The density variation reading device 1014 consists of a light source 1062 which irradiates the surface of the medium with a light, a sensor 1073 which receives the reflected light, a collimation device 1077 which makes the collimated value of the reflected light which is installed in front of the sensor 1073 and any selected conversion circuit. A density variation correction circuit 1020 corrects drive parameters for the recording head based on a density variation which is read from the test pattern. A collimated value setting device 1101 makes variable the collimated value set by the collimation device 1077 depending upon the type of the medium for recording in which a test pattern is recorded and recording parameters. Thus it is possible to read or correct density variation correctly. |
