HP Designjet H35000 and H45000 Printer Series - UV Bulb Expectations (5400)

Introduction

Many customers have questions about the bulbs for the UV-curing lamps on the HP Designjet H35000/H45000

Printer series (ColorSpan 5400uv Series). This document deﬁ nes the factors that contribute to bulb wear and what to

expect from your UV system.

Terminology

The UV lamp system consists of these parts:

Lamp Housings

The two ventilated boxes on the left and right sides of the carriage. Each lamp housing is conceptually equivalent

to a light ﬁ xture in your home or ofﬁ ce: it is a reasonably permanent hardware item. The lamp housing is directly

connected to the electrical current and contains the necessary components to light up a UV bulb (see below). The

housing also has a self-contained cooling apparatus.

UV Bulb

The actual “light bulb” that emits visible and UV light energy. Just like a light bulb in any ﬁ xture in your home or

ofﬁ ce, the UV bulb is a consumable item and will eventually need to be replaced. Bulb life is a major topic of the

remainder of this document.

The photographs below show each of these items.

Lamp Housing on Carriage

Lamp removed and inverted,

showing bulb and reﬂ ector

Bulb Removed from Lamp

Housing

Bulb Life

Bulb life is deﬁ ned as the period in which the bulb will emit enough ultraviolet (UV) light energy to cure the ink within

the available exposure time.

For the ﬁ rst 200-300 hours of on-time, the energy emitted by the bulbs is constant. After that the energy emission

begins to decline. Between 300-500 hours of use, the decline is sufﬁ cient so that most bulbs no longer emit enough

energy to cure output in the fastest printmodes with the lamp at its lowest power setting. If you are not printing in the

faster modes, the number of hours before this occurs may be higher; but see the “Additional Notes on Bulb Life” sec-

tion (below) for important details. Whenever this point is reached, there are two options to extend the life of the bulb:

1. Increase power from low to medium, and then from medium to high. Increasing the power setting causes the

bulb to emit more UV energy. Heat output will increase as well, so see the section below about power settings

and heat generation.