IMAGE SENSOR POSITIONING APPARATUS AND METHOD

• US 20140036096A1
• Filed: 08/01/2013
• Published: 02/06/2014
• Est. Priority Date: 08/06/2012
• Status: Active Grant

• Current Assignee: Axis AB (Canon Inc.)
• Original Assignee: Axis AB (Canon Inc.)
• Inventors: STERNGREN, Fredrik
• Granted Patent: US 9,602,810 B2
• Time in Patent Office: Days
• US Class Current: 348/188
• 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 substantially parallel 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 substantially parallel 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;

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 substantially parallel light beams has a first direction of approach towards the light receiving plane of the image sensor, wherein the second group of substantially parallel 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 substantially parallel 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 substantially 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 substantially parallel 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 substantially 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 substantially parallel 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 substantially parallel 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 substantially parallel light beams differs from the color of the light beams of the second group of substantially parallel light beams.

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

8. Method according to claim 1, wherein projecting of the first group of substantially parallel 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 substantially parallel 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 substantially parallel light beams includes the act of collimating the light.

10. Method according to claim 1, wherein at least one of the predetermined patterns includes parallel lines having a length stretching substantially from one edge of the effective surface of the image sensor to an opposite edge of the effective surface of the image sensor.

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

12. Method according to claim 1, wherein the act of projecting a first group of substantially parallel light beams includes sending substantially parallel light beams into the camera at an angle being substantially orthogonal to the light receiving plane of the image sensor, redirecting the substantially parallel 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.

13. A measuring system for measuring a position of an image sensor in a camera, the system comprising:

a first light source arranged to emit towards the image sensor a first group of substantially parallel light beams representing a first predetermined pattern;

a second light source arranged to emit towards the image sensor a second group of substantially parallel light beams representing a second predetermined pattern; and

an input configured to receive image data captured by the image sensor;

wherein the first light source and the second light source are directed to make the light beams from a respective light source intersect the light beams from the other light source.

14. Measuring system according to claim 13, wherein the first light source comprises a light emitting device, a light collimator and a pattern generator.

15. Measuring system according to claim 13, wherein the first light source comprises a light director arranged to redirect light beams from a light emitting device into a direction intersecting the light beams from the second light source.