Introduction to Printer Binary Printing, Adjustable Binary Printing, and Grayscale Printing

From the perspective of droplet size generation, there are three different printing modes:

• Binary Printing

Also known as “Native” printing.

Each pixel contains 1 bit of data (1 bpp).

Each pixel is either 0 or 1 droplet, and all nozzles of the printhead eject droplets of the same size each time they fire.

• Adjustable Binary Printing

Also known as “Binary Multi-Pulse”.

Each pixel contains 1 bit of data (1 bpp), and the pixel value is 0 or 1.

Multiple droplets are fired and coalesce into a single droplet on the substrate to produce the desired droplet size.

This printing mode allows users of single-pass printers to adjust ink laydown without changing the printhead type.

• Grayscale Printing

Also known as “Multi-Bits”.

Each pixel contains 2 bits (2 bpp) or 3 bits (3 bpp) of data.

By controlling each nozzle to eject a specific number of droplets that combine into one, each pixel can be printed with different droplet sizes.

In grayscale mode, each nozzle can produce small, medium, or large droplets within each firing cycle based on image requirements.

 Binary vs. Grayscale: Key Differences

* In binary printing, each nozzle can only produce one fixed droplet size, and the resulting pixel is simply inked or not inked.

* In grayscale printing, the system can produce variable droplet sizes, offering major advantages:

  * Sharper, more readable text

  * Cleaner edges

  * Better color matching using less ink

  * High-quality output without sacrificing productivity in single-pass systems

 How Droplets Are Generated

Droplets are formed by applying precise, non-resonant, time-controlled waveforms with variable amplitude to the piezoelectric elements.

 Waveform Requirements in Different Printing Modes

 1. Binary Printing

The printhead requires a single optimized trapezoidal pulse to generate the designed native droplet size.

 2. Adjustable Binary Printing

The printhead uses a sequence of increasing-amplitude trapezoidal pulses to generate droplets approximately 1.5–3× the native size.

In this mode:

* Each nozzle can only fire ON or OFF.

* All pulses in the waveform must be used.

* The system cannot select droplet size per pixel, since firing is binary.

A multi-pulse amplifier is required for this printing mode.

 3. Grayscale Printing

In each firing cycle, the system can instruct each nozzle to eject:

* a small droplet

* a medium droplet

* a large droplet

Droplet size selection is based on the grayscale value of each pixel.

This mode requires:

* a multi-pulse amplifier, and

* multi-bit data encoding/decoding capability