Ideas for making an image sensor

[AdrianMachin]

I know it may sound ridiculous, but I've always thought of making a simple homemade image sensor. Is it possible to make a primitive image sensor using many photocells or other electronics parts? or it's IMPOSSIBLE AT ALL?

I'd like to know if there are DIY methods for making an image sensor.

 

[Drakkith]

Sounds feasible. You could place an array of photocells near the focal point of a lens system and read out the voltage on each cell. It just won't give you a very good image.

 

[tech99]

I know it may sound ridiculous, but I've always thought of making a simple homemade image sensor. Is it possible to make a primitive image sensor using many photocells or other electronics parts? or it's IMPOSSIBLE AT ALL?

I'd like to know if there are DIY methods for making an image sensor.

I have done it using a mechanical scanning device and using a photo transistor or a photo multiplier as the pick up device. This produced a 32 line picture at 12.5 fps which I could view mechanically or by digital conversion to 625 line analogue system.
If you use individual photo cells in a grid, there is a huge problem with the quantity of devices required and the method of switching.
These issues were being looked at in the 19th Century when the challenge of devising a practical TV system arose, and Paul Nipkov suggested scanning as a means of avoiding thousands of photo cells.

 

[AdrianMachin]

I have done it using a mechanical scanning device and using a photo transistor or a photo multiplier as the pick up device. This produced a 32 line picture at 12.5 fps which I could view mechanically or by digital conversion to 625 line analogue system.
If you use individual photo cells in a grid, there is a huge problem with the quantity of devices required and the method of switching.
These issues were being looked at in the 19th Century when the challenge of devising a practical TV system arose, and Paul Nipkov suggested scanning as a means of avoiding thousands of photo cells.

Thanks. How about the optical part? Is there any projects or videos on this?

 

[256bits]

Thanks. How about the optical part? Is there any projects or videos on this?

Early mechanical television
http://www.earlytelevision.org/mechanical.html
http://www.earlytelevision.org/mechanical_tv.html

that should give you some ideas.

 

[AdrianMachin]

Early mechanical television
http://www.earlytelevision.org/mechanical.html
http://www.earlytelevision.org/mechanical_tv.html

that should give you some ideas.

Thanks. The attached image (Copyright Lee Krystek, 2002) cleared it more. But I have another question, how can I project an image from a normal lit environment on the disk bright enough? I have experienced with magnifiers and I could only project an image from a window lit from sunlight.

 

[256bits]

Thanks. The attached image (Copyright Lee Krystek, 2002) cleared it more. But I have another question, how can I project an image from a normal lit environment on the disk bright enough? I have experienced with magnifiers and I could only project an image from a window lit from sunlight.

Good question/ If one goes back in history they also had that same problem, hence the bright lights, and sweaty look of actors with makeup.
Makes me wonder now if the makeup was not there to cover up "blemishes" ( High Definition ) , but to give a more reflective surface to the skin of a person.

 

[tech99]

Thanks. The attached image (Copyright Lee Krystek, 2002) cleared it more. But I have another question, how can I project an image from a normal lit environment on the disk bright enough? I have experienced with magnifiers and I could only project an image from a window lit from sunlight.

In practice, a big lens is required, and the photo detector must be in a dark box and may require a condenser lens in front of the detector. If the disc is say, 50cm diameter, with 32 holes, then sufficient pick up for ordinary lights can be obtained by using a photo multiplier tube type 931. Results have also been obtained with photo transistors and photo voltaic solar cells, sometimes using discs of about 25cm. Another website of interest is nbtv.org.
The disc can also be used for simultaneous display, using some white LEDs with a diffuser panel.

 

[CWatters]

Good question/ If one goes back in history they also had that same problem, hence the bright lights, and sweaty look of actors with makeup.
Makes me wonder now if the makeup was not there to cover up "blemishes" ( High Definition ) , but to give a more reflective surface to the skin of a person.

A bit off topic but my father was a radio engineer involved in the early days of Television. The early black and white cameras had a strange response to colour so the actors had to wear strange coloured makeup including blues and blacks to "look right" on a B&W TV...