Single Air Pump Inkjet Printer Pressure Control

Solution Overview

Problem

Inkjet printers with high-density nozzles for high-resolution printing face challenges in generating necessary pressures for ink circulation, leading to increased printer size and cost due to separate air pumps for positive and negative pressure tanks, and limited design flexibility in air systems.

Innovation Solution

A single air pump is used to generate pressures in both tanks by controlling air opening valves to maintain set pressures, allowing the air systems to operate independently of their respective capacities, thus avoiding the need for matching air capacities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single air pump is used to generate pressures in both tanks, then the size and cost of the printer are reduced, but the design flexibility of air systems is limited due to equal air capacities requirement

Engineering Contradiction:

Improvenumber of air pumpsVSAvoiddesign flexibility of air systems

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the air pump operable in two distinct modes: a first operation mode for generating positive pressure in the positive pressure tank, and a second operation mode for generating negative pressure in the negative pressure tank. This dynamic switching capability allows a single air pump to perform functions that traditionally required two separate pumps, thereby reducing device complexity while maintaining design flexibility through controller-managed mode transitions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The air pump is designed with multi-functionality to serve dual purposes: it can generate both positive pressure (when operating in the first operation mode) and negative pressure (when operating in the second operation mode). This universal capability eliminates the need for separate positive and negative pressure generating devices, reducing the overall number of components while the controller ensures appropriate mode selection to maintain system adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Stress or pressure

If the positive pressure tank is disposed at a position higher than the inkjet head to generate hydraulic head pressure, then the needed pressure is generated, but the printer size increases

Engineering Contradiction:

Improvehydraulic head pressureVSAvoiddifference in height between tanks

Core Design Contradiction:

Stress or pressureVSLength of stationary object

Solution Approach 1:

The patent replaces the mechanical gravitational system (hydraulic head pressure requiring height difference) with a pneumatic system (air pump generating pressure directly). The air pump can generate the required positive pressure in the positive pressure tank without needing to be positioned at a higher elevation, thereby eliminating the need for large vertical space while maintaining the necessary pressure differential for ink circulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The air pump performs preliminary action by pre-generating the required positive pressure in the positive pressure tank before ink circulation begins. This eliminates the need to rely on gravitational potential energy from height difference, allowing the system to achieve the necessary pressure conditions through direct pneumatic pressurization rather than mechanical positioning.

Inventive Principle:

Principle #10Preliminary action

3Stress or pressure

If separate air pumps are provided for positive and negative pressure tanks to generate needed pressures, then the setting pressures are generated, but the size and cost of the printer increase

Engineering Contradiction:

Improvepressure generation capabilityVSAvoidnumber of air pumps

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

The air pump is designed with multi-functionality to serve dual purposes: it can generate both positive pressure (when operating in the first operation mode) and negative pressure (when operating in the second operation mode). This universal capability eliminates the need for separate positive and negative pressure generating devices, reducing the overall number of components while the controller ensures appropriate mode selection to maintain system adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent applies dynamics by making the air pump operable in two distinct modes: a first operation mode for generating positive pressure in the positive pressure tank, and a second operation mode for generating negative pressure in the negative pressure tank. This dynamic switching capability allows a single air pump to perform functions that traditionally required two separate pumps, thereby reducing device complexity while maintaining design flexibility through controller-managed mode transitions.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables the generation of setting pressures in both tanks using a single air pump while maintaining design flexibility, reducing the size and cost of the printer.

Implementation Method 1

circulates ink and generates a negative pressure appropriate for ejection of ink in a nozzle, by using a hydraulic head pressure (positive pressure) caused by the difference in height between the positive pressure tank and the inkjet head, and by using a negative pressure generated in the negative pressure tank by the air pump

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

a single air pump sucks air from the negative pressure tank and delivers air to the positive pressure tank, thereby generating a positive pressure in the positive pressure tank as well as a negative pressure in the negative pressure tank

Methodology Applied

Scientific EffectPositive pressure generation: Pressurisation

Implementation Method 3

a single air pump sucks air from the negative pressure tank and delivers air to the positive pressure tank, thereby generating a positive pressure in the positive pressure tank as well as a negative pressure in the negative pressure tank

Methodology Applied

Scientific EffectNegative pressure generation: Depressurisation

Data Source

PatentUS9340031B2Ink circulation type inkjet printer

Publication Date: 2016.05.17 RISO KAGAKU CORP

AI summary

A controller, upon a pressure of one tank of a positive pressure tank and a negative pressure tank reaching a setting pressure of the one tank prior to a pressure of the other tank reaching a setting pressure of the other tank after driving an air pump, sets an air opening valve opening time at each unit time according to a difference between the pressure of the one tank and the pressure of the other tank, and repeatedly drives one of a positive-pressure-side air opening valve and a negative-pressure-side air opening valve corresponding to the one tank to switch to and hold an air open state of the one tank for the set air opening valve opening time within the unit time, until the pressure of the other tank reaches the setting pressure of the other tank.