Daisy Wheel Printing

How it works

Daisy wheel printing is an impact technology that produces fully formed characters rather than building them from dots. Its defining component is the daisy wheel: a flat disk of radiating spokes, or petals, whose spoked silhouette resembles a daisy flower. Each spoke is tipped with a single raised, complete glyph, and a wheel typically holds around 96 characters covering letters, numerals, and symbols. Early wheels were metal; molded plastic later became common.

The printing cycle has three basic steps:

• A servo motor rapidly rotates the wheel to bring the required character's petal into position in front of the paper.
• A solenoid-driven hammer strikes the back of that petal, flexing the spoke forward so the raised character presses an inked ribbon against the paper, transferring a crisp, solid impression.
• The wheel and print carriage advance to the next position; many machines printed bidirectionally, left-to-right and right-to-left, for speed.

Because each character is a single solid shape, the result is a continuous letterform that is identical every time it prints. This is the source of the term letter-quality, meaning output visually comparable to a good office typewriter. Changing the typeface or character set is done by physically swapping the daisy wheel, and changing the ink color by swapping the ribbon.

History

The spoked type-wheel concept predates electronic computing. Authoritative accounts cite much earlier type-wheel patents as antecedents, including one attributed to Arthur Irving Jacobs in 1889 for the Victor index typewriter, and one attributed to A. H. Reiber of Teletype Corporation in 1939. These predate commercial viability and are treated as forerunners rather than the modern product.

The modern, commercially successful daisy wheel printer was developed at Diablo Data Systems of Hayward, California, around 1970 to 1972. Primary credit is genuinely debated across authoritative sources. Wikipedia credits a Diablo effort led by Andrew Gabor, who received two patents for the invention, while other reputable secondary sources and Qume-related corporate history credit David S. Lee, who developed the mechanism at Diablo before leaving to found Qume. The most defensible statement is that the technology was created at Diablo in the early 1970s, with David S. Lee and Andrew Gabor being the two names consistently associated with it, and that sources disagree on who deserves primary credit. No single sole inventor should be asserted.

Xerox acquired Diablo Data Systems in 1972, the best-documented date; one summary renders the year as 1970, but the better-sourced date is 1972. After the acquisition, David S. Lee left and co-founded Qume Corporation in 1973 with Robert E. Schroeder. Qume went on to become a dominant maker of daisy wheel printers.

Evolution

Daisy wheel printing evolved from mechanical typing into a computer output technology and then faded as newer methods matured.

• Late 1800s to early 1900s: antecedent type-wheels established the spoked-wheel typing concept in mechanical typewriters and teleprinters.
• Early 1970s: Diablo produced the first commercially successful computer-driven daisy wheel print mechanism.
• Mid-1970s to early 1980s: Diablo and Qume products became the dominant letter-quality output for minicomputers, word processors, and office automation. The Diablo 630, sold from around 1980, set the standard, and Diablo's command set became a de facto industry standard that later printers emulated.
• Consumer convergence: the mechanism was folded into electronic typewriters and lower-cost personal letter-quality printers by established makers.
• Mid-to-late 1980s: daisy wheel printing was displaced by improving dot-matrix printers offering near-letter-quality, and then by laser and inkjet printers.

Advantages

The strengths of daisy wheel printing are documented qualitatively; no specific speed, resolution, or price figures are asserted here.

• Letter-quality output: fully formed, solid characters comparable to a good office typewriter. This was its central selling point against early dot-matrix printers, whose characters were visibly built from dots.
• Sharp, consistent letterforms suitable for professional business correspondence, legal documents, and other formal output.
• Faster than an electric typewriter: documented sources describe daisy wheel computer printers as running substantially faster than a typewriter such as the IBM Selectric, with the Diablo 630 described as roughly double a Selectric's speed.
• Interchangeable type elements: swapping the wheel changed the entire typeface, font, or character set, offering flexibility that a fixed typebar or typeball offered less readily.
• Impact capability: as an impact device it could print through multi-part carbon forms, a genuine advantage over non-impact printers.
• Bidirectional printing and proportional spacing on higher-end models such as the Diablo 630.

Disadvantages

The limitations are likewise stated qualitatively.

• Cannot print graphics or arbitrary images: output is limited to the fixed set of characters physically present on the mounted wheel, a decisive weakness once affordable graphics-capable printers arrived.
• Limited character set at any moment: printing a symbol not on the current wheel required stopping and swapping wheels.
• Noisy operation: as a hammer-strike impact device it was loud, and quieter competing technologies used this as a selling point.
• Less flexible than emerging laser and inkjet printers for mixed text-and-graphics work as those technologies matured.
• Mechanical wear: the moving wheel, hammer, and ribbon are consumable or wearing parts.

Modern use

Daisy wheel printing is effectively obsolete for mainstream use and has been since the late 1980s, superseded by laser and inkjet printing. The residual uses that persisted reflect its two intrinsic strengths, solid letter-quality characters and true impact printing.

Legacy electronic typewriters using daisy or thimble elements continued in some offices after the standalone printers themselves faded, and niche impact and carbon-copy form contexts historically favored impact devices, although dot-matrix impact printers largely fill that role today. There is no documented significant contemporary commercial market for new daisy wheel printers; today they are primarily of historical and collector interest.

Relationship to other technologies

Daisy wheel printing sits at the intersection of the typewriter and the computer printer.

• Typewriters: it is a direct descendant of typewriter typing. It competed with and improved upon the IBM Selectric typeball, or golf ball, mechanism, offering a swappable flat wheel and, in computer form, higher speed. Documented sources explicitly benchmark daisy wheel letter quality against the Selectric, described as the de facto quality standard of its time.
• Thimble printers: a closely related impact variant used a cup- or thimble-shaped molded element instead of a flat wheel. NEC's Spinwriter, introduced in 1977, is the best-known thimble-element device and is a related variant rather than a flat daisy wheel.
• Dot-matrix printers: the primary impact competitor, initially inferior in quality but far more flexible, since a single mechanism could produce graphics and any character. It eroded the daisy wheel market from below.
• Laser and inkjet printers: non-impact successors offering full graphics, quieter operation, and unlimited fonts, which ultimately displaced daisy wheel printers. Diablo's command set was so entrenched that even early laser printers offered Diablo emulation.

Relationship to manufacturers

Several companies shaped the daisy wheel era.

• Diablo Data Systems: originator of the commercial daisy wheel printer, acquired by Xerox in 1972.
• Xerox: owned Diablo and marketed daisy wheel printers as well as lower-cost typewriter versions.
• Qume Corporation: founded in 1973 by David S. Lee, formerly of Diablo, and Robert E. Schroeder; a major daisy wheel maker. Qume was acquired by ITT in 1978 and later by Wyse Technology.
• Established typewriter makers such as Brother Industries and Silver Seiko adapted to daisy wheel technology.
• Apple marketed an Apple-branded daisy wheel printer.
• DEC and Hewlett-Packard resold or relabeled the Diablo 630 under their own designations.

Related printer families

A handful of product lines are securely documented as daisy wheel or closely related devices. Some historical model designations circulate in secondary summaries but are not confirmed by the primary sources consulted here and are therefore omitted rather than presented as a definitive list.

• Diablo 630: the flagship daisy wheel printer, sold from around 1980, whose command language became the de facto industry standard emulated by later printers, including early laser printers.
• Qume CrystalPrint family: letter-quality products from Qume.
• Apple Daisy Wheel Printer: Apple's rebadged letter-quality printer.
• NEC Spinwriter: a thimble-element variant, related to but mechanically distinct from the flat daisy wheel.

Timeline

1. 1889

   Type-wheel antecedent: a daisy-type wheel patent attributed to Arthur Irving Jacobs for the Victor index typewriter.

2. 1939

   Antecedent patent attributed to A. H. Reiber of Teletype Corporation.

3. c. 1970–1972

   The daisy wheel computer printer is developed at Diablo Data Systems; primary credit between Andrew Gabor and David S. Lee is debated across sources.

4. 1972

   Xerox acquires Diablo Data Systems (best-documented date; one source renders 1970).

5. 1973

   Qume Corporation founded by David S. Lee and Robert E. Schroeder.

6. 1977

   NEC introduces the Spinwriter, a related thimble-element printer.

7. 1978

   ITT acquires Qume, reported at 164 million dollars.

8. c. 1980

   The Diablo 630 reaches the market; its command set becomes a de facto standard.

9. Mid-to-late 1980s

   Decline as dot-matrix, laser, and inkjet printers take over.