Optical unit and imaging apparatus

• US 9,488,846 B2
• Filed: 08/12/2014
• Issued: 11/08/2016
• Est. Priority Date: 09/05/2013
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Hayashi, Tsuneo
• Primary Examiner(s): Chang, Audrey Y
• Application Number:
  US14/457,836
• Publication Number:
  US 20150062699A1
• Time in Patent Office: 819 Days
• Field of Search: 359/465, 348 45- 50, 348/57, 348/58, 396/324, 356/364
• US Class Current: 1/1
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: H04N 13/337 using polarisation multiplexing

Abstract

An optical unit includes a condensing lens which condenses light from an object; a pupil splitting polarization separation element which separately outputs two linearly polarized light beams of which polarizing directions are different from the condensed light using a left eye polarization separation region and a right eye polarization separation region which are formed by having a pupil splitting line which is orthogonal to an optical axis as a border; a polarizing direction conversion element which converts polarizing directions of the two linearly polarized light beams which are output from the pupil splitting polarization separation element; and a rotation driving unit which rotates the pupil splitting polarization separation element and the polarizing direction conversion element in an optical axis rotational direction.

Claims

1. An optical unit for providing two orthogonally polarized light beams, comprising:

a condensing lens which condenses light from an object;

a pupil splitting polarization separation element having a left eye polarization separation region and a right eye polarization separation region that are divided by a pupil splitting line which is orthogonal to an optical axis, wherein the left eye polarization separation region and the right eye polarization separation region output two respective linearly polarized light beams with orthogonal polarization directions;

a polarizing direction conversion element comprising a half-wave plate for converting the polarization directions of the two linearly polarized light beams output from the pupil splitting polarization separation element; and

a rotation driving unit which rotates the pupil splitting polarization separation element and the polarizing direction conversion element in an optical axis rotational direction with the rotation angle of the polarizing direction conversion element being half of the rotation angle of the pupil splitting polarization separation element to generate the two orthogonally polarized light beams to have different axis angles, wherein the rotation angle of the polarizing direction conversion element is the same as the angle of the crystal axis of the polarizing direction conversion element.

2. The optical unit according to claim 1,

wherein the left eye polarization separation region and the right eye polarization separation region in the pupil splitting polarization separation element are formed using a polarizer, and a transmission axis in the left eye polarization separation region is orthogonal to a transmission axis in the right eye polarization separation region.

3. An imaging apparatus comprising:

an optical unit for providing two orthogonally polarized light beams which includes

a condensing lens which condenses light from an object,

a pupil splitting polarization separation element having a left eye polarization separation region and a right eye polarization separation region that are divided by a pupil splitting line which is orthogonal to an optical axis, wherein the left eye polarization separation region and the right eye polarization separation region output two respective linearly polarized light beams with orthogonal polarization directions,

a polarizing direction conversion element comprising a half-wave plate for converting the polarization directions of the two linearly polarized light beams output from the pupil splitting polarization separation element, and

a rotation driving unit which rotates the pupil splitting polarization separation element and the polarizing direction conversion element in an optical axis rotational direction with the rotation angle of the polarizing direction conversion element being half of the rotation angle of the pupil splitting polarization separation element to generate the two orthogonally polarized light beams to have different axis angles, wherein the rotation angle of the polarizing direction conversion element is the same as the angle of the crystal axis of the polarizing direction conversion element; and

an image obtaining unit configured to obtain a left eye image and a right eye image by individually receiving the two linearly polarized light beams of which polarizing directions are converted by the polarizing direction conversion element.

4. The imaging apparatus according to claim 3, further comprising:

an image rotation processing unit which rotates the left eye image and the right eye image.

5. The imaging apparatus according to claim 3,

wherein the image obtaining unit obtains the left eye image and the right eye image by individually receiving the two linearly polarized light beams using an imaging element in which two polarizing plates of which directions of transmission axes are different from each other are formed on a light receiving face.

6. The imaging apparatus according to claim 3,

wherein the image obtaining unit includes a polarization beam splitter which disperses the two linearly polarized light beams, and two imaging elements which receive one of the two linearly polarized light beams which are dispersed by the polarization beam splitter, respectively.

7. The imaging apparatus of claim 3,

wherein the rotation driving unit is configured to rotate the polarizing direction conversion element and the pupil splitting polarization elements such that the polarizing directions of the two linearly polarized light beams incident on the imaging element remain the same when the pupil splitting polarization element rotates, without rotating the imaging element in the optical axis rotation direction.