Optical disc image forming apparatus

Abstract

When an image is formed on an optical disc, a pickup is moved by a pitch S in the radial direction of the optical disc together with a slider supporting the pickup. An objective lens within the pickup is shifted by a predetermined shift amount L by an actuator to emit a laser beam. The temperature in the vicinity of the pickup is detected by a temperature sensor. If the detected temperature has increased as much as, or more than, a threshold ΔTth relative to the temperature prior to the beginning of the formation of an image, a movement setting unit sets the slider movement pitch S and the objective lens shift amount L to small values so as to reduce the maximum drive current applied to the actuator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an embodiment of an optical disc image forming apparatus according to the present invention;

FIG. 2 is a view describing the basic operation of a slider and an objective lens;

FIGS. 3A and 3B are views showing how a slider movement pitch and a lens shift amount are changed during temperature rise;

FIG. 4 is a graph showing the temperature increase around a pickup resulting from the change in the lens shift amount; and

FIG. 5 is a view showing a flowchart of the image forming process.

Claims

1. An optical disc image forming apparatus for forming a visible image associated with image data by irradiating an optical disc with a laser beam, the apparatus comprising: a spindle motor adapted to rotate the optical disc;a pickup having a laser beam source adapted to generate a laser beam for the image data, an objective lens adapted to irradiate the optical disc with a laser beam, and an actuator adapted to shift the objective lens in the radial direction of the optical disc;a stepping motor adapted to move a slider supporting the pickup in the radial direction of the optical disc;a temperature sensor adapted to detect temperature in the vicinity of the pickup; anda movement control unit adapted to control the operation of the stepping motor and the actuator;wherein the movement control unit changes a movement pitch of the slider and a shift amount of the objective lens in response to a temperature detected by the temperature sensor.

2. The optical disc image forming apparatus of claim 1, wherein the movement control unit changes the slider movement pitch and the objective lens shift amount in response to the detected temperature every time the slider is moved by the stepping motor.

3. The optical disc image forming apparatus of claim 1, wherein if the temperature detected by the temperature sensor has increased as much as, or more than, a threshold relative to the temperature prior to the beginning of the formation of an image, the movement control unit sets the slider movement pitch and the objective lens shift amount to small values.

4. The optical disc image forming apparatus of claim 3, wherein when setting the objective lens shift amount to a small value, the movement control unit reduces the maximum drive current applied to the actuator.

5. An optical disc image forming apparatus for forming a visible image associated with image data by irradiating an optical disc with a laser beam in accordance with image data, the apparatus comprising: a spindle motor adapted to rotate the optical disc;a pickup having a laser beam source adapted to generate a laser beam for the image data, an objective lens adapted to irradiate the optical disc with a laser beam, and an actuator adapted to shift the objective lens in the radial direction of the optical disc;a stepping motor adapted to move a slider supporting the pickup in the radial direction of the optical disc;a temperature sensor adapted to detect the temperature in the vicinity of the pickup; anda movement control unit adapted to control the operation of the stepping motor and the actuator;wherein the movement control unit reduces the maximum drive current applied to the actuator if the temperature detected by the temperature sensor is equal to or greater than a predetermined temperature.