Image sensor positioning apparatus and method

• US 9,602,810 B2
• Filed: 08/01/2013
• Issued: 03/21/2017
• Est. Priority Date: 08/06/2012
• Status: Active Grant

• Current Assignee: Axis AB (Canon Inc.)
• Original Assignee: Axis AB (Canon Inc.)
• Inventors: Sterngren, Fredrik
• Primary Examiner(s): AYNALEM, NATHNAEL B
• Application Number:
  US13/957,221
• Publication Number:
  US 20140036096A1
• Time in Patent Office: 1,328 Days
• Field of Search: 348/190, 356/237.2, 356/239.3, 356/508
• US Class Current: 1/1
• CPC Class Codes: H04N 17/002 for television cameras
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils

Abstract

A method is provided for positioning an image sensor having a light receiving plane within a camera and a system is provided for identifying the position of an image sensor. The method comprises projecting a first group of substantially parallel light beams representing a first predetermined pattern onto the light receiving plane of the image sensor at an angle of incidence, projecting a second group of substantially parallel light beams representing a second predetermined pattern onto the light receiving plane of the image sensor at an angle of incidence, registering positions on the light receiving plane of the image sensor where the light beams are detected by the image sensor, generating adjustment information based on the registered positions, indicating if the present position of the image sensor is an erroneous position or not, and adjusting the position of the image sensor based on the adjustment information.

Claims

1. A method for positioning an image sensor including a light receiving plane within a camera, the method comprising:

projecting a first group of collimated light beams representing a first predetermined pattern onto the light receiving plane of the image sensor at an angle of incidence α

₁ for the first group;

projecting a second group of collimated light beams representing a second predetermined pattern onto the light receiving plane of the image sensor at an angle of incidence α

₂ for the second group, wherein at least one of the predetermined patterns includes parallel lines having a length stretching from one edge of the effective surface of the image sensor to an opposite edge of the effective surface of the image sensor;

registering positions of the projected light beams on the light receiving plane of the image sensor;

generating adjustment information, based on the registered positions, indicating if the present position of the image sensor is an erroneous position or not; and

adjusting the position of the image sensor based on the adjustment information.

2. Method according to claim 1, wherein the first group of collimated light beams has a first direction of approach towards the light receiving plane of the image sensor, wherein the second group of collimated light beams has a second direction of approach towards the light receiving plane of the image sensor, and wherein the first and second directions are intersecting directions.

3. Method according to claim 1, wherein the first group of collimated light beams has a first direction of approach towards the light receiving plane of the image sensor, this first direction has a first component directed orthogonally towards the light receiving plane of the image sensor and a second component directed orthogonally to the first component, wherein the second group of collimated light beams has a second direction of approach towards the light receiving plane of the image sensor, this second direction has a first component directed orthogonally towards the light receiving plane of the image sensor and a second component directed orthogonally to the first component, and wherein the second component of the first direction and the second component of the second direction are oppositely directed.

4. Method according to claim 1, wherein the angles of incidence α

₁, α

₂ of the collimated light beams of the first group and the second group, respectively, are at least 30 degrees.

5. Method according to claim 1, wherein the angles of incidence α

₁, α

₂ of the collimated light beams of the first group and the second group, respectively, are at least 45 degrees.

6. Method according to claim 1, wherein the color of the light beams of the first group of collimated light beams differs from the color of the light beams of the second group of collimated light beams.

7. Method according to claim 6, wherein a difference in color between the colors of the two groups of collimated light beams corresponds to at least 25 nm difference in wavelength.

8. Method according to claim 1, wherein projecting of the first group of collimated light beams onto the light receiving plane of the image sensor is performed during a first time period, wherein projecting of the second group of collimated light beams onto the light receiving plane of the image sensor is performed during a second time period, and wherein the first time period includes at least one time period not included in the second time period.

9. Method according to claim 1, wherein the act of projecting a first and a second group of collimated light beams includes the act of collimating the light.

10. Method according to claim 1, further comprising determining a distance between the pattern projected using the first group of collimated light beams and the pattern projected using the second group of collimated light beams, and determining at least one erroneous state based on the distance between patterns.

11. Method according to claim 1, wherein the act of projecting a first group of collimated light beams includes sending collimated light beams into the camera at an angle being orthogonal to the light receiving plane of the image sensor, redirecting the collimated light beams, at a redirection surface, towards the light receiving plane of the image sensor at the angle of incidence α

₁, wherein the redirection of the light beams is not performed until the light beams have passed a lens mount of the camera.

12. A method for positioning an image sensor including a light receiving plane within a camera, the method comprising:

generating collimated light forming a plurality of predetermined patterns;

projecting a first plurality of collimated light beams representing a first predetermined pattern onto the light receiving plane of the image sensor at an angle of incidence α

₁ for the first predetermined pattern;

projecting a second plurality of collimated light beams representing a second predetermined pattern onto the light receiving plane of the image sensor at an angle of incidence α

₂ for the second predetermined pattern;

registering positions of the projected light beams on the light receiving plane of the image sensor;

generating adjustment information, based on the registered positions, indicating if the present position of the image sensor is an erroneous position or not; and

adjusting the position of the image sensor based on the adjustment information.