Introduction

The sensor is a back-illuminated rolling shutter, i.e. the image is acquired through the back side without any obstacles like wiring or circuits. Therefore, a wider range of light is collected on the photo-diode.

Feature	Description
Manufacturer	Sony
Sensor name	IMX178
Max. frames per second	60
Device Structure	CMOS image sensor
SNR_max [dB]^1/	41.6
DNR (normal / HDR) [dB]^1/	71.6 / -
Image size	1/1.8
Number of effective pixels	3096 (H) x 2080 (V)
Unit cell size	2.4µm (H) x 2.4µm (V)
ADC resolution / output	12 bit → 8/10/(12)

¹ Measured accord. to EMVA1288 with gray scale version of the camera

Shutter modes

The sensor offers several shutter modes:

rolling shutter (mvShutterMode = "mvRollingShutter"),
rolling shutter flash (mvShutterMode = "mvRollingShutterFlash"), and
global reset release shutter (mvShutterMode = "mvGlobalReset").

With the rolling shutter the lines are exposed for the same duration, but at a slightly different point in time.

The exposure time which is set corresponds to the exposure time of each line.
The exposure signal corresponds to the exposure of the first line.

Note: Moving objects together with a rolling shutter can cause a smear in moving objects.

With the rolling shutter flash

The exposure time which is set corresponds to the time where all lines are exposed simultaneously.
The exposure signal corresponds to the time where the last line starts until the first line ends.

The global reset release shutter starts the exposure of all rows simultaneously and the reset to each row is released simultaneously, too. However, the readout of the lines is equal to the readout of the rolling shutter: line by line:

Note: This means, the bottom lines of the sensor will be exposed to light longer! For this reason, this mode will only make sense, if there is no extraneous light and the flash duration is shorter or equal to the exposure time.

Spectral Sensitivity

Figure 1: Spectral sensitivity BVS CA-SF2-0064ZG

Figure 2: Spectral sensitivity BVS CA-SF2-0064ZC

Timings

Name	Value
InternalLineLength	420 (10 bit) / 495 (12 bit)
VerticalBlankLines	31
SensorInClock	54 MHz
NumberOfLVDS	8

Free running mode

In free running mode, the sensor reaches its maximum frame rate. This is done by overlapping erase, exposure and readout phase. The sensor timing in free running mode is fixed, so there is no control when to start an acquisition. This mode is used with trigger mode Continuous.

To calculate the maximum frames per second (FPS_max) in free running mode you will need following formula:

                   InternalLineLength          ImageHeight + VerticalBlankLines 
FrameTime =  ------------------------------ * ----------------------------------
                     SensorInClock                        1000

If exposure time is lower than frame time:

                 1
FPS_max =  ------------
            FrameTime

If exposure time is greater than frame time:

                 1
FPS_max =  --------------
            ExposureTime

Connection

Frame rate calculator

Note: The calculator returns the max. frame rate supported by the sensor. Please keep in mind that it will depend on the interface and the used image format if this frame rate can be transferred.

Note: The exposure time step width is limited to the sensor's row time of 9.44 us and therefore
- auto exposure with very low exposure times will perform with relatively large increments and
- exposure mode = TriggerWidth (if available) will perform with a jitter corresponding to the row time.

The following trigger modes are available:

Setting (GenICam)	Mode / Setting (obsolete "Device Specific")	Description
`"TriggerSelector = FrameStart"` `"TriggerMode = Off"`	Continuous	Free running, no external trigger signal needed.
`"TriggerSelector = FrameStart"` `"TriggerMode = On"` `"TriggerSource = Software"` `"ExposureMode = Timed"` To trigger one frame execute the TriggerSoftware@i command then.	OnDemand	Image acquisition triggered by command (software trigger).
`"TriggerSelector = AcquisitionActive"` `"TriggerMode = On"` `"TriggerSource = <desired Line>"` `"TriggerActivation = LevelLow"` `"ExposureMode = Timed"`	OnLowLevel	Start an exposure of a frame as long as the trigger input is below the trigger threshold. (No FrameTrigger!)
`"TriggerSelector = AcquisitionActive"` `"TriggerMode = On"` `"TriggerSource = <desired Line>"` `"TriggerActivation = LevelHigh"` `"ExposureMode = Timed"`	OnHighLevel	Start an exposure of a frame as long as the trigger input is above the trigger threshold. (No FrameTrigger!)
`"TriggerSelector = FrameStart"` `"TriggerMode = On"` `"TriggerSource = <desired Line>"` `"TriggerActivation = FallingEdge"` `"ExposureMode = Timed"`	OnFallingEdge	Each falling edge of trigger signal acquires one image.
`"TriggerSelector = FrameStart"` `"TriggerMode = On"` `"TriggerSource = <desired Line>"` `"TriggerActivation = RisingEdge"` `"ExposureMode = Timed"`	OnRisingEdge	Each rising edge of trigger signal acquires one image.
`"TriggerSelector = FrameStart"` `"TriggerMode = On"` `"TriggerSource = <desired Line>"` `"TriggerActivation = AnyEdge"` `"ExposureMode = Timed"`	OnAnyEdge	Start the exposure of a frame when the trigger input level changes from high to low or from low to high.

Device Feature And Property List

Frame rate calculator
Mode:	Overlapping exposure and readout
Product:	BVS CA-SF
Output image bit depth:	8 bit 12 bit 16 bit
Pixel clock:	54 MHz
Image width:	pixels
Image height:	pixels
Exposure time:	us
Device throughput:	Device Sensor Throughput Device Link Throughput
Link speed:	USB 2.0 USB 3.0

Frame rate (max):	1/s
	ExposureTime > FrameTime → FPS = 1 / ExposureTime