Camera unit and method for controlling an image sensor in a camera unit

1. A camera unit, comprising:

an image sensor including a photoelectric pixel matrix, a timing unit controlling said image sensor, 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 connection based on a series bus,

a control connection based on a series bus, and

a global-reset signal connection separate from the data connection and the control connection, configured to transmit a timed global-reset signal from the image sensor to the host module, and

the timing unit of the image sensor is configured, by means of a selected control command given by the host module, to initiate an imaging procedure and to create the timed global-reset signal at intervals and to send it also to the host module to indicate the start of imaging.

2. The camera unit according to claim 1 , in which the image sensor is configured to create and transmit viewfinder images at intervals and the host module includes means for controlling at least one imaging procedure operation independently, based on the timed global-reset signal.

3. 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.

4. The camera unit according to claim 3 , wherein the mechanical shutter together with its driver is connected directly to the image sensor, by means of the strobe-signal connections.

5. 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 means of a selected control command through a control bus by the host module;

creating a timed global-reset signal at intervals;

transmitting the timed global-reset signal from the image sensor to the host module;

controlling, by the host module, a timing of at least one operation relating to the imaging procedure based on the timed global-reset signal; and

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

6. The method according to claim 5 , wherein the host module controls a mechanical shutter.

7. The method according to claim 6 , wherein the driver of the mechanical shutter is configured 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 timed global-reset signal.

8. The method according to claim 5 , wherein the host module controls a flash.