Step

Sensor status

Status

saturated

Maximum

signal

Noise

level

Modulated light

amplitude

Ambient to

modulated light

Action

AMR

1

Saturation or bright ob-

ject within scene

yes

Repeat measurement with

decreased integration time and/or illumination

2

Saturation or bright ob-

ject within scene

no

above

Repeat measurement with

decreased integration time and/or illumination

4

No object detected

no

below

below

Repeat measurement with

increased integration time or illumination

3

Over-exposure or bright

object within scene

no

below

above

> 1'000 LSB

Repeat measurement with

decreased integration time or illumination

4

No object detected

no

below

above

<

50 LSB

Repeat measurement with

increased integration time or illumination

5

Too much ambient-light

no

below

above

50 LSB … 1'000 LSB

> 60 db (or > 70 dB)

Repeat measurement with

increased integration time or illumination

6

Object detected

no

below

above

Excellent: 100 … 1'000 LSB

Sufficient

50 … 100 LSB

< 60 db (or < 70 dB)

No action necessary

Table 7: Quality decision matrix (per pixel)

1.3.6. Ambient-light measurement (optical power-meter)

Instead of getting distance data, the epc610 chip can measure the ambient-light level per pixel. Features of this powerful function are:

■ Watching the ambient-light level during the distance measurement to prevent faulty conditions or to use the information for compensation

reasons.

■ Use the ecp610 as an optical power-meter e.g. for brightness control.

■ or in combination of both: e.g. everywhere where there is a presence or an absence of an object, the illumination needs to be controlled.

■ Grayscale imaging.

way:

t

INT-REF-DC

t

INT-DC

e.g.

E

nW

/cm

2

LSB

⋅

103

μ s

1.6

μ s

⋅1'000 LSB = 792μ W /cm

2

For the distance measurements, it is not necessary to do the ambient-light measurement all the time. Usually, the ambient-light conditions

are changing slowly. It makes sense to do it as a control, in order to have enough detection margin in the receiver electronics or if the qual-

ity is indicating a faulty measure.

Notes:

modulated light amplitude.

■ The ambient-light measurement is a metering functionality only, which can be used for distance correction or ambient-light reading. It is

completely independent of the chip internal ambient-light suppression function that eliminates DC light components from the measure -

ment signal (refer to chapter 1.3.4. Ambient-light suppression).

■ Take care that the ambient-light measurement follows the same procedure of Figure 13. This means that all 4 frames must be mandato-

rily read. The result is: 4 similar, time sequential, black& white pictures.

1.3.7. Temperature metering

Two on-chip temperature sensors at the opposite sides of the pixel field give back uncalibrated temperature readings. The readings of

each row also contain the two temperature values.

■ This allows the compensation of the signal drifts caused by changing thermal conditions in the light source and the sensor.

■ If the user does his own calibration (e.g. °C or F), he can use it as a temperature sensor too.

© 2014 ESPROS Photonics Corporation

Characteristics subject to change without notice

14 / 34

Datasheet epc610 - V1.7

www.espros.ch