Founder Doug Cavanaugh, left, jokes with his mother, Ruby, in front of his Tustin branch on Tuesday. Thirty years ago, Cavanaugh opened his first Ruby's Diner, named after his mother, at Balboa Pier in Newport Beach. (KEVIN CHANG / December 4, 2012)

Doug Cavanaugh had to disobey his mother to make her a household name.

The founder of Ruby's Diner, which will celebrate its 30th anniversary this weekend, got the idea for his restaurant chain when he jogged past a dilapidated building on the Balboa Pier. He envisioned a 1940s-style diner similar to the ones his mother, Ruby Cavanaugh, frequented as a child, and he realized that her first name would look perfect on a sign.

The only problem: She wasn't keen on it.

"We were originally going to call it the Balboa Diner, but that didn't have a lot of longevity to it," Doug said Tuesday afternoon at a booth inside the Ruby's in Tustin. "So we decided I was going to call it Ruby's Diner, and I asked Mom for her permission, and she immediately said, 'Absolutely not.'

"So, like any good son, I completely ignored her and did it. And so, on opening day, I had her walking out and I gave everybody the high sign, flipped on the neon sign where it said 'Ruby's.' She immediately began to pummel me. She got over it very quickly when she realized she was the star of the show."

Ruby, sitting next to him in the booth, added that she really hadn't been that offended.

"It was quite a thrill, really it was," she said. "It was cute."

Over the last three decades, that thrill hasn't subsided for Ruby, who often visits the restaurant's locations and gets besieged for autographs by children after they realize who she is. Usually, they hand her crayons, which the restaurant provides for young guests, and she responds by drawing a caricature of herself along with a signature.

Friday, she may be in demand more than ever, as Ruby's commemorates three decades with a private party on the Balboa Pier. Before that, the general public is invited to enjoy menu items at their original Reagan-era prices: $2.15 for a RubyBurger, $1 for fries and $1.60 for a milkshake.

"It's going to be a very fast-and-furious day of flying burgers out the window," said Doug, who grew up in Tustin and ran a restaurant on Nantucket Island before launching Ruby's.

The discount will be offered until the Balboa restaurant closes at 4 p.m. for the private celebration; other Southern California locations, excluding Shake Shacks or airport restaurants, will stay open until regular closing hours. The chain, which has 38 locations nationwide, operates throughout Orange County, including on the Seal Beach and Huntington Beach piers.

Those locations by the sea, according to Doug, complement the restaurant's theme of leaving modernity behind.

"The really neat thing for us is that it allows people to escape back to our era," he said. "As you're walking down that pier, the years pass by and you're surrounded by classic 1940s and '50s Americana."

michael.miller@latimes.com

Twitter: @MichaelMillerHB

If You Go

What: 30th anniversary celebration of Ruby's Diner

Where: Balboa Pier, off East Balboa Boulevard across from the Balboa Pavilion, Newport Beach

When: 7 a.m. to 4 p.m. Friday; other Southern California locations (excluding Shake Shack and airports), 7 a.m. to closing

Cost: Free to attend; menu items offered at original 1982 prices

Information: (949) 675-7829 or http://www.rubys.com

Did You Know?

In honor of Ruby's Diner's 30th anniversary, here are some fun facts about the restaurant:

*The red and white color scheme inside the restaurant was inspired by Ruby Cavanaugh's first name. She joked that if her name were Pearl, the interior would have been entirely white.

*The real-life Ruby also served as the model for the drawing of the waitress on the restaurant's menu — it was based on a photo of her in her high school drill team uniform.

*The restaurant's original menu was tiny — just hamburgers and hot dogs for entrees, plus a handful of sides and sweet treats. It's expanded since then to include breakfast, veggie burgers and more.

*Founder Doug Cavanaugh says the chain's management discourages servers from addressing groups of customers as "guys," which he considers too informal. He prefers "folks."