Prism apparatus and camera apparatus including the same

Patent metadata

Field	Value
Publication number	US-12216293-B2
Application number	US-201917292335-A
Country	US
Kind code	B2
Filing date	Nov 8, 2019
Priority date	Nov 9, 2018
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

The present disclosure relates to a prism apparatus, and a camera apparatus including the same. The prism apparatus according to an embodiment of the present disclosure may include: a prism configured to reflect input light toward a first reflected direction; a first actuator configured to change an angle of the prism about a first rotation axis to change the first reflected direction based on a first control signal; a lens configured to output the light reflected by the prism toward a second reflected direction; and a second actuator configured to change an angle of the lens about a second rotation axis to change the second reflected direction based on a second control signal. Accordingly, it is possible to implement the optical image stabilization (OIS) for the prism.

First claim

What is claimed is:

1. A prism apparatus comprising:
a prism configured to reflect input light toward a first reflected direction;
a first actuator configured to change an angle of the prism about a first rotation axis to change the first reflected direction based on a first control signal;
a lens configured to output the light reflected by the prism toward a second reflected direction; and
a second actuator configured to change an angle of the lens about a second rotation axis to change the second reflected direction based on a second control signal,
wherein in response to a movement causing rotation of the prism about the first rotation axis by a first angle and rotation of the lens about the second rotation axis by a second angle, the first actuator is configured to rotate the prism in a third direction opposite the first reflected direction by a third angle in response to the first control signal, and the second actuator is configured to rotate the lens in a fourth direction opposite the second reflected direction by a fourth angle in response to the second control signal.

2. The prism apparatus of claim 1 , further comprising a frame in which the lens is mounted,
wherein the second actuator comprises a first driving device and a second driving device connected to both ends of the frame, and changes the second reflected direction by moving at least one of the first driving device and the second driving device.

3. The prism apparatus of claim 1 , wherein the lens comprises a liquid lens, and
wherein by applying an electrical signal to the liquid lens, the second actuator changes a curvature of the liquid lens.

4. The prism apparatus of claim 1 , wherein the first rotation axis of the prism is perpendicular to the second rotation axis of the lens.

5. The prism apparatus of claim 1 , further comprising:
a first hall sensor configured to sense an angle change of the prism based on a first magnetic field; and
a second hall sensor configured to sense an angle change of the lens based on a second magnetic field.

6. The prism apparatus of claim 1 , wherein the first actuator comprises a first drive magnet and a first drive coil.

7. The prism apparatus of claim 6 , further comprising:
a prism holder configured to secure the prism;
a first yoke coupled to a rear of the prism holder;
the first drive magnet coupled to a rear of the first yoke;
a first coil holder including a plurality of protrusions protruding toward the prism holder, each of the plurality of protrusions having an opening, and the openings of the plurality of protrusions defining the first rotation axis,
wherein the first drive coil is disposed between the first coil holder and the first yoke, and
wherein the prism holder includes a plurality of bosses configured to engage with the openings of the plurality of protrusions to allow rotation of the prism about the first rotation axis.

8. The prism apparatus of claim 1 , wherein the second actuator comprises a second drive magnet.

9. The prism apparatus of claim 1 , wherein a refractive index of the prism is 1.7 or greater.

10. The prism apparatus of claim 3 , wherein the second actuator comprises:
a lens driver configured to apply the electrical signal to the liquid lens; and
a sensor device configured to sense a curvature of the liquid lens formed based on the electrical signal.

11. The prism apparatus of claim 10 , wherein the sensor device is configured to sense a size of an area or the change in the area, of a boundary region between an insulator on an electrode in the liquid lens and an electroconductive aqueous solution.

12. The prism apparatus of claim 11 , wherein in response to the size of the area or the change in the area, of the boundary region between the insulator on the electrode in the liquid lens and the electroconductive aqueous solution, the sensor device is configured to sense capacitance formed by the electroconductive aqueous solution and the electrode.

13. The prism apparatus of claim 11 , wherein the second actuator further comprises:
a plurality of conductive lines provided for delivering a plurality of electrical signals, output from the lens driver, to the liquid lens; and
a switching element disposed between any one of the plurality of conductive lines and the sensor device.

14. The prism apparatus of claim 10 , wherein the second actuator further comprises a processor configured to calculate a curvature of the liquid lens based on a capacitance sensed by the sensor device, and to output a pulse width modulation signal to the lens driver based on the calculated curvature and a target curvature.

15. The prism apparatus of claim 14 , wherein in response to the calculated curvature being less than the target curvature, the processor increases a duty cycle of the pulse width modulation signal.

16. A camera apparatus comprising:
a gyro sensor configured to sense a movement of the camera apparatus;
a prism apparatus configured to direct input light;
a lens apparatus comprising a plurality of lenses configured to be adjusted to achieve variable focus; and
an image sensor configured to generate an image signal based on the input light,
wherein the prism apparatus comprises:
a prism configured to reflect the input light toward a first reflected direction;
a first actuator configured to change an angle of the prism about a first rotation axis to change the first reflected direction based on a first control signal;
a lens configured to output the light reflected by the prism toward a second reflected direction; and
a second actuator configured to change an angle of the lens about a second rotation axis to change the second reflected direction based on a second control signal,

wherein in response to a movement causing rotation of the prism about the first rotation axis by a first angle and rotation of the lens about the second rotation axis by a second angle, the first actuator is configured to rotate the prism in a third direction opposite the first reflected direction by a third angle in response to the first control signal, and the second actuator is configured to rotate the lens in a fourth direction opposite the second reflected direction by a fourth angle in response to the second control signal.

17. The camera apparatus of claim 16 , wherein the image sensor receives light corresponding to an object being photographed from the prism apparatus while the image sensor is positioned perpendicularly to the object being photographed.

18. The camera apparatus of claim 16 , wherein one or more of the plurality of lenses are moved along an axis for achieving variable focus, and the axis is perpendicular to a direction of the input light which is input into the prism apparatus.

Assignees

• Lg Electronics Inc

Inventors

• Kang Hyungjoo
• Kim Kwanhyung
• Lee Dongryeol
• Hong Samnyol

Classifications

• G02B7/1805

  for prisms (G02B7/181 takes precedence) · CPC title

• G02B3/14

  of variable focal length · CPC title

• G02B27/646 Primary

  compensating for small deviations, e.g. due to vibration or shake (movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68) · CPC title

• G02B7/04

  with mechanism for focusing or varying magnification · CPC title

• G02B5/06 Primary

  Fluid-filled or evacuated prisms · CPC title