Device for obtaining the image and/or spectra of electron energy loss
View Patent ↗The inventive device for obtaining the electron energy loss image and/or spectra includes an image sensor, a control for at least two deflectors for alternately exposing at least two photosensitive parts of the image sensor, sensor reading means for generating the representative signal of an image captured by each photosensitive part of the image sensor, means for synchronizing the deflector and the reading means for successively controlling the exposition of the photosensitive part and the reading of the other photosensitive part for each photosensitive part and means for combining the two image parts in such a way that a spectrum is formed.
1. A device for acquiring images or electron energy loss spectra, said device comprising:
an image sensor;
control means for controlling at least two deflectors configured to expose, in alternation, at least two photosensitive portions of the image sensor;
reading means for reading the sensor, which means are configured to generate a signal representative of an image sensed by each photosensitive portion of the image sensor;
synchronization means for synchronizing the deflectors and the reading means, which synchronization means are configured to cause, for each photosensitive portion in succession, firstly said photosensitive portion to be exposed and secondly another, different photosensitive portion to be read; and
combination means for combining two image portions so as to form a spectrum.
2. A device according to claim 1 , wherein the synchronization means are adapted to cause different exposure times to be applied for different successive exposure time intervals.
3. A device according to claim 1 , wherein the synchronization means are configured to and take into account that reading speeds at which the different photosensitive zones are read are different.
4. A device according to claim 3 , wherein the reading means are adapted configured to perform, firstly line-by-line reading of each photosensitive portion and secondly accumulation of electrical charges from photosites of each photosensitive portion prior to reading.
5. A device according to claim 1 , further comprising summing means configured to sum values of the signals corresponding to different lines of a portion read line-by-line.
6. A device according to claim 1 , wherein the image sensor further comprises, for at least one photosensitive portion, at least two portions whose reading means are independent.
7. A device according to claim 1 , wherein the device further comprises two deflectors configured to shift the image in both directions of the image sensor.
8. A device according to claim 1 , further comprising a fast blanking deflector configured to shift the spectrum out of the detector during positioning of each other deflector serving to expose, in alternation, at least two photosensitive portions of the image sensor.
9. A device according to claim 1 , wherein the deflector that acts on the spectrum in an energy dispersive direction is an electrostatic type, a variation in potential being obtained by an electronic switch switches over instantly from a high reference voltage to ground.
10. A device according to claim 1 , wherein the deflectors are configured to shift the image in both directions of the image sensor.
11. A device according to claim 1 , wherein at least one of the deflectors is of a magnetic type.
12. A device according to claim 1 , wherein the device further comprises optical transfer means comprising at least one lens.
13. A device according to claim 1 , wherein the device further comprises a spectrometer configured to form an electron energy loss spectrum at the surface of the image sensor.
14. A device according to claim 1 , wherein the reading means of the sensor are configured to apply different gains to signals coming from the two photosensitive portions of the image sensor.