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Kálmán Tihanyi: Charge Storage, and the Patents RCA Bought

By Infinite Creation · Profile

Patent drawing from the work of Kálmán Tihanyi.

At a Glance

Kálmán Tihanyi (1897-1947) patented the charge-storage principle underlying practical electronic camera tubes from 1926. Charge storage is the step that separates a camera tube that theoretically works from one that is sensitive enough to broadcast with. RCA purchased his patents. His 1926 application is on the UNESCO Memory of the World Register. How much of the iconoscope should be credited to him rather than to Zworykin's RCA team remains disputed.

Lived: 1897-1947, Hungary
Anchor year: 1926, the charge-storage patent application
Strand: overlooked, the principle is his, the famous tube is not

Career

The problem as it stood

Campbell-Swinton's 1908 architecture had a fatal weakness nobody had solved: if each picture element is only read as the scanning beam sweeps past, it collects light for a vanishingly small fraction of the frame. The resulting signal is far too weak. This is why early electronic camera tubes needed studio lighting so fierce it was unusable.

What he actually did

From 1926 Tihanyi filed patents describing a camera target that accumulates photoelectric charge continuously across the whole frame time, storing it until the beam arrives to read and reset it. He called the concept, in his own framing, the storage principle, and applied it in his Radioskop design.

How it worked

Each element of a mosaic target acts as a tiny capacitor charged by incident light. Because it integrates over the entire frame period rather than the instant of scanning, the signal is stronger by roughly the number of picture elements, a factor of tens of thousands. That single change is the difference between a camera tube that needs blinding light and one that can work in a television studio.

What it made possible

Charge storage is the operating principle of the iconoscope, the image orthicon, the vidicon and, in a different physical form, the CCD and CMOS sensors in every camera today. It is arguably the single most important idea in the history of electronic imaging, and it is not attached to a household name.

What happened to him

Tihanyi sold patent rights internationally, including to RCA, and later worked on television-guided systems in Britain and Italy. He returned to Hungary and died in 1947, largely unrecognised. His daughter and later historians reconstructed the record. UNESCO added his 1926 application to the Memory of the World Register in 2001.

Where the credit landed

Tihanyi patented the charge-storage principle underlying practical electronic camera tubes from 1926, and RCA purchased his patents. His 1926 application is on the UNESCO Memory of the World Register. How much of the iconoscope's design should be credited to him rather than to Zworykin's RCA team remains disputed. This is the assignment-and-purchase pattern in its purest form: the principle enters a corporation and the corporation's name goes on the product.

Known For

Charge storage, not scanning, is what made electronic cameras usable, and it is the least famous key idea in television.
Buying a patent is a legitimate transaction that also erases a name from the popular story.
Every digital camera sensor today still works on the storage principle.

Knowledge Base

What You'll Learn

If you only remember one piece of physics from television's invention, make it this one.

Why storage multiplies sensitivity

Consider a 40,000-element image scanned 25 times a second. Without storage, each element is connected to the output for 1/40,000th of a frame, so it uses 1/40,000th of the light falling on it. With storage, it integrates light for the entire frame and dumps the accumulated charge when read. The available signal rises by roughly the element count. No amount of amplifier design substitutes for that, because amplifying a signal also amplifies its noise.

Where This Fits

Charge storage made camera tubes practical at the capture end of the chain traced in A History of Broadcast Technology.

FAQ

Q: Did Tihanyi invent the iconoscope?
A: He patented the charge-storage principle the iconoscope depends on, from 1926, and RCA bought his patents. How much of the iconoscope's design should be credited to him rather than to Zworykin's RCA team remains disputed among historians.

Q: What is charge storage, in one sentence?
A: Letting each picture element accumulate light for the whole frame and reading the stored charge when the beam arrives, instead of using only the light arriving at the instant of scanning.

Sources

The 1926 application is held in an international register, which is the strongest available record of what he described and when. Checked 20 August 2026.

UNESCO Memory of the World, Kalman Tihanyi's 1926 Patent Application Radioskop. The register entry, inscribed in 2001. It records a 1926 Hungarian application for a fully electronic television transmitting and receiving system introducing the accumulation and storage of electrical charges across each scanning cycle, with French and British patents following in 1928.