US 9900569

Patent Summary: US 9,900,569

A concise summary of US Patent 9,900,569, including details of ongoing litigation.

Title: Projection-type image display device

Assignee: Maxell, Ltd.

Inventors: Eriko Nagata, Shinji Onodera, Satomi Morishita, Naoya Oka, Masaaki Iwanaga

Filing Date: July 4, 2014

Issue Date: February 20, 2018

Abstract:
This projection-type image display device is provided with: a lamp drive unit that drives a lamp; a lamp voltage detection unit that detects a lamp interelectrode voltage (hereinafter referred to as a lamp voltage); an image correction unit that corrects image qualities of image signals to be supplied to an image display element; and a control unit that controls a correction quantity of the image correction unit on the basis of the lamp voltage detected by means of the lamp voltage detection unit. Consequently, deterioration of visibility of a projection image can be suitably suppressed.

Plain-Language Overview of Independent Claims:

This patent has one independent claim.

Claim 1: This claim describes a projection-type image display device that uses a discharge lamp as its light source. The core of the invention is a system designed to counteract the natural dimming of the lamp as it ages. It does this by:

1. Detecting the lamp's voltage: A "lamp voltage detection unit" measures the voltage between the lamp's electrodes.
2. Tracking usage time: A "lighting period managing unit" keeps a record of the total time the lamp has been used.
3. Correcting the image: An "image correction processing unit" adjusts the quality of the image signal (e.g., brightness, contrast) before it's sent to the image display element (like an LCD panel).
4. Controlling the correction: A "control unit" is the brain of the operation. It takes the lamp's voltage and its total usage time and uses this information to determine how much the image needs to be corrected to compensate for the lamp's reduced brightness. This ensures that the projected image's visibility is maintained over the life of the lamp.

In essence, the device automatically adjusts the image to make it look better as the lamp gets older and dimmer, using the lamp's voltage and usage history as indicators of its deteriorating performance.

Litigation Status:

As of the current date, US Patent 9,900,569 is the subject of ongoing litigation. Maxell, Ltd. has asserted this patent in a lawsuit against CORETRONIC CORP. and Optoma Corp. in the U.S. District Court for the Eastern District of Texas (Case 5:24-cv-00088). The case involves allegations of patent infringement. Court documents indicate that the court has denied the defendants' motion to dismiss the complaint.