# How Printers Manage Power States and Sleep Timers

> A method for printers to intelligently decide whether to reset their sleep timer based on the type of network activity they encounter.

- **Patent:** US RE48925
- **Original title:** USRE48925E1 - Information processing apparatus, method for controlling power state shift and clearing or not clearing a shift time measured
- **Owner:** Canon Inc
- **Granted:** 2022
- **Status:** Active
- **Times cited:** 0
- **Field:** consumer_electronics, mechanical, energy

## What it does

This patent describes a power management system for printers that operate across four distinct power states. The system uses a timer to track how long the device has been in a low-power state (the third state) before it should shut down completely (the fourth state). The clever part is how it treats the timer when the printer wakes up partially: if the printer wakes up for a major task, like printing a document, it resets the timer. However, if it wakes up for a minor network inquiry that it cannot fully process, it keeps the original timer running, ensuring the printer still shuts down on schedule.

## What it does NOT cover

- Does not cover power management systems that only use two or three power states.
- Does not cover devices that reset their sleep timer regardless of the type of network packet received.
- Does not cover power state transitions that are triggered by physical buttons rather than network events.

## The clever bit

The system distinguishes between 'meaningful' wake-up events and 'inconsequential' network pings, choosing to reset the sleep timer only for the former.

## Real-world examples

1. Canon office laser printers
2. Network-connected multifunction office copiers

## Why it matters

In large office environments, printers are often left on 24/7. This patent helps balance the need for energy efficiency (shutting down when idle) with the need for availability (waking up for actual print jobs). By ignoring 'noise' or minor network pings, the device avoids unnecessary energy consumption while remaining ready for actual work.

## Frequently asked questions

### What does How Printers Manage Power States and Sleep Timers cover?

A method for printers to intelligently decide whether to reset their sleep timer based on the type of network activity they encounter.

### Who owns patent US RE48925?

Canon Inc owns this patent, granted in 2022.

### When does this patent expire?

This patent is expected to expire on February 8, 2042, when the invention enters the public domain.

### What problem does this patent solve?

In large office environments, printers are often left on 24/7. This patent helps balance the need for energy efficiency (shutting down when idle) with the need for availability (waking up for actual print jobs). By ignoring 'noise' or minor network pings, the device avoids unnecessary energy consumption while remaining ready for actual work.

### What does this patent NOT cover?

Does not cover power management systems that only use two or three power states.

**Full plain-English explainer:** https://patentbrief.org/patent/us/RE48925/wrist-worn-activity-tracker

**Original patent:** https://patents.google.com/patent/USRE48925

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._