1.  Field of the Invention
The present invention relates to a drive signal generating apparatus and a drawing apparatus. 
2.  Description of Related Art
In recent years, along with the popularization of information recording media such as an optical disk, drawing apparatuses that draw an image on the drawing surface of an optical disk have been widely used. 
Various specific methods are available to draw an image on an optical disk.  For example, there is a method of ejecting ink onto the label surface of an optical disk to draw an image thereon.  Additionally, there is a method of applying a laser beam onto the label surface of an optical disk to draw an image thereon.  In the latter case, a thermosensitive layer formed on the drawing surface of the optical disk is irradiated with the laser beam and altered, thereby drawing a desired image on the drawing surface of the optical disk. 
Japanese Unexamined Patent Application Publication No.  2003-203348 and Japanese Patent Translation Publication No.  2006-512718 each disclose a technique of applying a laser beam onto the thermosensitive surface of an optical disk by employment of an optical pickup section, thereby forming an image thereon.  Note that Japanese Unexamined Patent Application Publication No.  2003-187471 discloses a technique of correcting a drive waveform input to a stepping motor so as to realize traverse feeding with high accuracy. 
In the case of forming the desired image (picture images, characters, and the like) on the drawing surface of the optical disk, there is a strong demand for suppressing degradation in quality of an image to be finally drawn. 
For example, when the desired image is drawn on the drawing surface of the optical disk by the application of the laser beam, the optical pickup section is required to move stepwise with high accuracy.  However, the drawing surface of the optical disk has no mark indicating a position within the surface.  Accordingly, in order to suppress the degradation in quality of the image to be finally drawn, it is necessary to increase the feed accuracy of a feed mechanism for the optical pickup section.  Actually, however, there is a problem in that it is difficult to increase the feed accuracy of the feed mechanism itself of the optical pickup section due to various causes (for example, machining accuracy of a mechanical transmission mechanism, and variation in characteristics of a drive source). 
In order to solve the above-mentioned problem, an amount of arrangement deviation of the optical pickup section with respect to a target position may be measured in advance, and the optical pickup section or an objective lens may be moved under certain conditions depending on the measurement results, thereby drawing an image on the drawing surface of the optical disk.  In this case, data representing the amount of arrangement deviation of the optical pickup section may be stored in a non-volatile memory such as a flash memory according to the number of movements of the optical pickup section or the objective lens.  When an amount of data which represents the amount of arrangement deviation of the optical pickup section and which is stored in the non-volatile memory is increased, however, there is a problem in that available memory space of the non-volatile memory necessary for other processing becomes insufficient.