SAN JOSE, Calif. – Apple Inc. (Nasdaq: AAPL) alleged that Samsung Electronics Co. changed the design of its smartphone icons to resemble those on the iPhone, supporting its claim with an internal Samsung document presented to a jury in California.

At its multibillion-dollar patent trial in federal court in San Jose on Wednesday, Apple displayed excerpts of a 2010 internal Samsung report in which the South Korean company did a side-by-side comparison of its icon designs next to those of the iPhone. The report recommended that Samsung alter icons that weren’t as user-friendly as those on Apple’s devices.

Susan Kare, a former Apple graphics designer paid $80,000 to be an expert witness, said the icons for the companies’ current competing products – both are square with round edges and displayed on the device in rows of four – are “confusingly similar.” Kare also told the jury that she mistook a Samsung smartphone for an iPhone while visiting the office of Apple’s lawyers.

“I would usually think of myself as someone who is pretty granular in looking at graphics and I mistook one for the other,” Kare said. “In addition to my formal analysis, I had the experience of being confused.”

Apple and Samsung are the world’s largest makers of the high-end handheld devices that blend the functionality of a phone and a computer. The trial is the first before a U.S. jury in a battle being waged on four continents for dominance in a smartphone market valued by Bloomberg Industries at $219.1 billion. Each company is trying to convince jurors that its rival infringed patents covering designs and technology.

2010 Report

One slide from Samsung’s March 2010 “Relative Evaluation Report” shown to Kare compares applications on the iPhone with those on a Samsung GT-i9000 smartphone. The report concludes that the iPhone interface has “instant recognizability due to highly intuitive icon usage,” whereas the Samsung interface has “difficult differentiation due to icons that are duplicative or are intuitively deficient.”

The “Directions for Improvement” in the report are: “Change replicate icons and select and use highly intuitive icons,” and shorten long application names, according to the document.

Apple is using Kare’s testimony to advance its claims that Samsung phones infringe the software design of the iPhone. The company started making that argument last week with witness Scott Forstall, the company’s senior vice president in charge of iPhone and iPad software, and continued this week with testimony from another paid expert witness, industrial designer Peter Bressler.

$2.5 Billion

Apple seeks $2.5 billion for its claims that Samsung infringed patents. Samsung, based in Suwon, South Korea, countersued and will present claims that Apple is infringing two patents covering mobile-technology standards and three utility patents. Apple, based in Cupertino, California, also wants to make permanent a preliminary ban it won on U.S. sales of a Samsung tablet, and extend the ban to Samsung smartphones.

When Kare was shown at least 10 Samsung phones in court, she said the application screens on all of them are “substantially similar overall” to that described in Apple’s patent.

“The similarities I saw were the regular grid, the rows of four icons, the colorful mix of icons that are square with rounded corners,” she said.

In addition to patent infringement, Apple contends that Samsung’s copying of the look of the iPhone and iPad has diluted the values of its iconic brands. To prove infringement of the trademarked look, Apple must prove that consumers are confused as to which company makes the phone or tablet computer.

Kare is at least the second Apple witness to testify about customer confusion. Bressler told the jury Aug. 6 about data in a report showing that the most common reason some Best Buy Co. customers return Samsung’s Galaxy Tab 10.1 tablet computer is because they thought they had bought the iPad 2.

Cross-Examination

During cross-examination, Samsung’s attorney, Charles K. Verhoeven, highlighted differences between the companies’ devices. He showed Kare a Samsung phone and asked her to walk him through the steps required to arrive at the application screen she was asked to analyze. When he turned the device on, “Samsung” illuminated. After it was electronically unlocked, Verhoeven demonstrated, through Kare, that a customer had to navigate the phone’s home screen to get to the application screen.

“Wouldn’t you agree that by the time the consumer turns on the phone, and goes through the steps we looked at, seeing the Samsung sign prominently for several seconds,” Verhoeven asked, “that the consumer knows it’s a Samsung phone?”

“I’m not an expert in consumer behavior, and that kind of user experience,” Kare replied. “I’m really focused on graphic user interface, so I’m not sure I’m qualified to answer that.”

Kare, now at Susan Kare User Interface Graphics in San Francisco, has done images for Facebook Inc. and Microsoft Corp., according to her website.

The trial is scheduled to resume Aug. 10.

The case is Apple Inc. v. Samsung Electronics Co. Ltd., 11- cv-01846, U.S. District Court, Northern District of California (San Jose).