Apparatus and method for imaging lens alignment using a virtual test image

Method for aligning a lens module with respect to an image sensor, the method comprising the steps of:

• providing a holographic film including a test chart pattern;
• illuminating the holographic film with a light source to generate a virtual image of the test chart pattern;
• mounting the image sensor on an image sensor holder;
• mounting the lens module on a lens module holder between the holographic film and the image sensor such that the virtual image of the test chart pattern is viewable by the image sensor through the lens module;
• and
• with the image sensor, viewing the virtual image which is located at a virtual distance from the image sensor that is different from a physical position of the holographic film, whereby to align the lens module with respect to the image sensor.

Method for manufacturing a camera module, the method comprising the steps of:

• providing a holographic film including a test chart pattern;
• illuminating the holographic film with a light source to generate a virtual image of the test chart pattern;
• mounting an image sensor on an image sensor holder;
• mounting a lens module on a lens module holder between the holographic film and the image sensor such that the virtual image of the test chart pattern is viewable by the image sensor through the lens module;
• with the image sensor, viewing the virtual image which is located at a virtual distance from the image sensor that is different from a physical position of the holographic film, whereby to align the lens module with respect to the image sensor;
• and thereafter
• fixing the lens module and the image sensor to each other to form a camera module after the lens module and the image sensor have been aligned.