Camera Unit and Method for Controlling an Image Sensor in a Camera Unit

• US 20090251584A1
• Filed: 12/07/2005
• Published: 10/08/2009
• Est. Priority Date: 12/07/2005
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Alakarhu, Juha
• Granted Patent: US 8,035,689 B2
• Time in Patent Office: Days
• US Class Current: 348/333.10
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 25/7795 Circuitry for generating timing or clock signals

Abstract

The invention relates to a camera unit, comprising an image sensor (10), a mechanical shutter (16), a host module (12), and connections between them, in particular a data and control connection (D1, C1) between the image sensor and the host unit. In the image sensor (10), there is a photoelectric pixel matrix (101), a timing unit controlling it, an electronic shutter (ERS), and a ‘global reset’ circuit for resetting the pixels simultaneously. The said data and control connection comprises: a data connection (D1) based on a series bus, a control connection (C1) based on a series bus, and a global-reset signal connection (G1, G2) separate from these. The invention also relates to a method for controlling an image sensor in a camera unit.

Claims

1. A camera unit, comprising:

an image sensor, including a photoelectric pixel matrix, a timing unit controlling it, an electronic shutter, and a ‘

global reset’

circuit for resetting the pixels simultaneously, and I/O means for transmitting image data and for receiving imaging commands,

a mechanical shutter,

a host module including corresponding I/O means for receiving image data and for transmitting imaging commands, and

a data and control connection between the image sensor and the host unit,

wherein said data and control connection comprises;

a data connections based on a series bus,

a control connection based on a series bus, and

a global-reset signal connection separate from these.

2. The camera unit according to claim 1, in which the image sensor is arranged to create and transmit viewfinder images at intervals, wherein the timing unit of the image sensor is arranged, by means of a selected control command given by the host module, to initiate an imaging procedure and to create a timed global-reset signal at intervals and to send it also to the host module to indicate the start of imaging and the host module includes means for controlling at least one imaging procedure operation independently, based on this timing signal.

3. The camera unit according to claim 1, in which the image sensor is arranged to create and transmit viewfinders images at intervals, characterized wherein the host module is arranged to transmit a global-reset signals to the image sensor, which is arranged to initiate from it the imaging procedure and the host module includes means for controlling the operation of at least one imaging procedure independently, based on this timing signal.

4. The camera unit according to claim 3, wherein the image sensor is arranged to create a broken frame from the packet currently being transmitted, if the global-reset signal coincides with a packet being transmitted.

5. The camera unit according to claim 1, wherein between the image sensor and host module there are strobe-signal connections, in order to control the mechanical shutter through the host module.

6. The camera unit according to claim 1, wherein the mechanical shutter together with its driver is connected directly to the image sensor, by means of the strobe-signal connections.

7. A method comprising:

creating viewfinder images by an image sensor of a camera unit equipped with an electronic rolling shutter at intervals at a reduced resolution;

transmitting the viewfinder images over a data bus to a host module;

transferring to an imaging state by suspending the viewfinder operation;

initiating the imaging procedure by transmitting a global-reset signal from the host module to the image sensor and by saving at least one image-sensor time delay relating to the global-reset signal in the host module;

controlling the imaging procedure independently from the host module, without receiving a control signal from the imaging sensor; and

resuming to the viewfinder operation, after the image data being read by the image sensor and being transmitted over the data bus to the host module.

8. The method according to claim 7, wherein the host module controls a mechanical shutter.

9. The method according to claim 7, wherein the host module controls a flash.

10. The method according to claim 8, characterized in wherein the driver of the mechanical shutter is arranged to be programmable and the host module programs the timing of the driver before imaging and operation is controlled in imaging directly by means of the global-reset signal.

11. A camera unit comprising an image sensor, a mechanical shutter, a host module, and connections between them, and in which the image sensor includes a timing unit for controlling the imaging procedure and the timing of the imaging procedure is adapted to the selected signal, the host module includes means for simulating the imaging procedure, in order to control independently the timing of the mechanical shutter and/or a flash.