Oceanus "OCW-SG1000ZE": Reaching new heights in solar-powered radio-controlled watches after 50 years in the watch industry

October 2024 marks the 50th anniversary of Casio's entry into the watch business, and six brands have released commemorative models to celebrate the occasion. One of these is the Oceanus OCW-SG1000ZE. This is more than just a commemorative piece; it's a new solar-powered radio-controlled watch that embodies the development approach deeply rooted in the company, Casio Computer Co., Ltd.

Casio Oceanus "OCW-SG1000ZE" created to commemorate the 50th anniversary of its watch business

　Casio Computer Co., Ltd. (hereafter referred to as Casio) released the Casiotron in November 1974. This model was the company's first wristwatch. 2024 marks the 50th anniversary of Casio's entry into the watch business. To mark this milestone, Casio is releasing several commemorative models. The first model was the reissued Casiotron, released in February, followed by the "Sky and Sea" in May and the "Zero to One" in October.

"Zero to One" is Toshio Kashio's development philosophy, and is characterized by its embodying the idea of ​​"creating one from zero," which is still deeply rooted in the company today. Toshio is one of the founding family who founded Casio together with his brother Tadao and younger brother Kazuo, and is known as an inventor, including the Casiotron. To evoke this philosophy as the "light of beginning," all models are clad in black and gold.

The six models released as "Zero to One" are Casiotron, G-SHOCK, Oceanus, Edifice, Pro Trek, and BABY-G. Of these, this article will take a closer look at the Oceanus "OCW-SG1000ZE."

　This model features a design that incorporates the black and gold theme colors of the "Zero to One" campaign, based on the previous Oceanus "S6000." Additionally, the date wheel (calendar disc), which was previously hidden from the dial except when viewed through a small date window, is now exposed, and the date wheel is now colored in a gradation color that changes from purple to blue. While these design features are what first catch your eye on this commemorative model, the real highlight is found beneath the dial. It uses the newly developed "Gallium Tough Solar."

　We interviewed Takayasu Sato and Akihiro Kuroba, who were involved in the planning and development of the OCW-SG1000ZE. From what they said, we learned that this is a completely new solar-powered radio-controlled watch that was only possible because it inherited the development philosophy of "creating something from nothing," which is deeply rooted in Casio, and because of its commitment to its customers.

We need to create something that gives a sense of evolution and surprise.

　Takayasu Sato is the leader of the product planning department. He has been working on Oceanus for about six years and is always involved in the planning and development of new products for the brand. He spoke to us about what kind of commemorative model he had in mind when he was planning this model.

"(The OCW-SG1000ZE) is a model commemorating the 50th anniversary of Casio's watch business, but 2024 also marks the 20th anniversary of the birth of the Oceanus. To mark this milestone, we have decided to produce a worldwide limited edition of 350 units. The mission of the Oceanus is to 'convey Casio's analog movement technological capabilities and commitment to its products.' That's why we decided to pursue 'being an Oceanus' to the fullest extent."

While the company believes in "being an Oceanus," it is also worth noting that the design and development was not limited to cosmetic changes to the previous model, but was based on the idea of ​​"creating something from nothing."

"Up until now, the Oceanus has been a driving force in the manufacturing technology and evolution of Casio's analog movements. So, at this milestone of its 50th anniversary, the Oceanus had to release something that evokes evolution and surprise. With this in mind, I decided to develop something new for the 350th commemorative model."

"Being an Oceanus," Casio's approach to development, and the watchmaking technology the company has cultivated over the years have all come together in Gallium Tough Solar.

Space or Casio? Newly developed Gallium Tough Solar

　The OCW-SG1000ZE is equipped with a new movement. The person in charge of developing this movement is Akihiro Kuroba of the Planning Department. He has been involved in the planning and development of Oceanus for eight years. However, he is not only in charge of the Oceanus, but also of movements for high-end lines such as the MR-G. So, what kind of solar cell is Gallium Tough Solar? Kuroba describes it as "a technology that lets you feel the universe on your watch."

"All OCEANUS models are equipped with Tough Solar (Casio's solar power generation system). One challenge with this mechanism is that the dial must be made of a material that allows light to pass through (to allow the solar cell to receive the light). This places restrictions on the colors and materials that can be used. Casio has overcome this restriction through its own unique designs that reduce power consumption, enabling it to generate power with less light and efficiently converting incoming light into electricity. By developing light-shielding, dispersion-type solar cells and in-dial solar, we have achieved high efficiency, which has made it possible to color the dial and reduce the area of ​​the solar cell. However, with the newly developed Gallium Tough Solar, we have succeeded in making the dial out of metal for the first time in an OCEANUS."

What is Gallium?

　Gallium is a semiconductor material, and the new movement is based on a gallium compound, specifically gallium indium phosphide. According to Kuroba, solar cells made from silicon are generally used, including solar panels for homes. This work, on the other hand, is a gallium compound. He said that solar cells made from this material are mainly used in the space industry.

"They are used as solar cells for JAXA (Japan Aerospace Exploration Agency). Sharp is the manufacturer of these solar cells for JAXA. Sharp is the only Japanese company whose solar cells have been certified by JAXA, and this time we asked Sharp to develop this gallium compound solar cell for wristwatches. Incidentally, Sharp's gallium compound solar cell was installed on the Small Landing Demonstration Vehicle (SLIM), which made Japan's first successful moon landing this year." "There was a lot of excitement within the company when SLIM successfully landed on the moon," Sato replied.

　The beauty of gallium is its high efficiency.

　First, they are suitable for miniaturization because they boast approximately 2 to 5 times the efficiency of silicon solar cells in the same area. Also, compared to silicon solar cells, gallium solar cells have superior power generation efficiency under high illumination such as on a sunny day, which increases the battery charging speed in such environments.

　However, because it is a rare metal, there is the drawback that manufacturing costs are high.

Development to specialize in watches

　What does Kuroba mean when he says "developed for wristwatches"?

"Rather than just using the satellite version as is, Casio made a number of requests. Specifically, we asked them to change the structure of the electrodes that extract power from the solar panel. Ordinary solar panels have electrodes on the light-receiving surface. However, in a wristwatch, the electrode terminals are on the back cover of the solar panel. This is because they need to be highly densely mounted and connected to a secondary battery. For this reason, we worked with Sharp to develop a structure that changes the orientation of the electrodes. Also, because satellites are in space, they generate power using sunlight. But wristwatches need to be able to be charged using fluorescent lights or other indoor light. That's why we worked with Sharp to select a gallium compound that can be used with indoor light."

　With the Gallium Tough Solar technology thus created, Kuroba spoke with the biggest smile of the entire interview, describing its value as "Space or Casio?"

"At present, I don't think there are many examples of gallium compounds being used in solar cells in consumer devices other than Casio. In other words, it's either space or Casio. It's romantic to wear space on your wrist."

Mass production is the key

　However, this is not the first time that a G-SHOCK has used Gallium Tough Solar. To commemorate the 35th anniversary of G-SHOCK in 2018, a limited edition of 35 pieces was released the following year, and to commemorate the 40th anniversary of G-SHOCK in 2023, only one piece was released, both of which were equipped with Gallium Tough Solar movements. Both of these models are crafted from 18K yellow gold.

　These two rare G-SHOCKs are special one-off models launched as part of a dream project. The newly produced OCW-SG1000ZE, on the other hand, will be produced in 350 units. While this number is small, the company's adoption of Gallium Tough Solar in the Oceanus was made possible by reviewing its quality control and production system in preparation for its first mass production.

Where can Gallium Tough Solar be used?

　Gallium Tough Solar's superior efficiency makes it easier to miniaturize and provide even higher performance than conventional Tough Solar watches. Now that a mass production system is in place, what benefits has this part brought to the Oceanus?

"How can we take advantage of the efficiency of Gallium Tough Solar? This was an area that was discussed extensively between the (movement) developers and the designers. In the end, we decided to eliminate the constraints of the dial. We developed a watch that 'reaches a new level of solar radio-controlled watches with an entirely new concept.'"

　In other words, the evolution of functionality has led to the evolution of design.

"With previous Tough Solar models, the solar cell was placed under the dial. However, by using Gallium Tough Solar, we were able to place the date wheel under the dial, with a crescent-shaped solar cell below that. The date wheel is also made of metal. It's stainless steel. Because Gallium Tough Solar is highly efficient, sufficient power can be generated just from the gap in the date display."

　Unlike ordinary date wheels, the date on the date wheel is skipped. This is to make the light-blocking area uniform. "The size of the gap between the first and second digits is different, so by skipping the date, we make the light reception uniform."

　Furthermore, Kuroba emphasized that the benefit of Gallium Tough Solar is not only that the dial is made of metal, but also that it creates a three-dimensional effect: "Because of its unique structure, it has a three-dimensional effect that is difficult to achieve with solar radio-controlled watches."

　Incidentally, the gaps in the dial also allow standard radio waves to pass through. If the watch were made of metal, the radio waves would also be reflected and would not reach the antenna. The antenna is reused from the previous model.

"Of course, it's not just the dial, but it's also compatible with mobile link functionality and is equipped with world time and stopwatch functions, so I think it's a new movement worthy of being called a flagship."

Creating a special "Oceanus-like" feel

　The adoption of gallium solar powers the OCW-SG1000ZE, further embodying the OCEANUS concept of "elegance." Together with this component, it is a model that exudes the OCEANUS feel while maintaining a special feel within the "Zero to One" framework.

　Mr. Sato had this to say about the exterior:

"Along with Gallium Tough Solar, the key features are the sapphire crystal bezel and the Oceanus Blue color. The exterior of this model is well-made and is aimed at the same category as high-end models like the S6000. Take, for example, this sapphire crystal bezel. The S7000's is round, but the S6000's has 24 facets, and the OCW-SG1000ZE's has 48 facets. If it were round, all you'd need to do is use a bit. But this is faceted. First, a large, thick block of round sapphire crystal is carved out, and then 12 facets are carved around it. Sapphire crystal is the second hardest crystal after diamond, so the process of carving these 12 facets is quite difficult. After the 12 facets are carved, another diagonal cut is made to create 12 more facets, and then another 24 facets are left on that surface, which is quite a time-consuming process. Even the slightest misalignment is noticeable, so the work is done very carefully."

　What surprised me was that, according to Mr. Sato, each facet of the sapphire crystal is polished three times. This model has 48 facets, so each facet is polished three times. This polishing process is the same as for the regular model, so it inevitably ends up being produced in small quantities.

"We outsource the sapphire crystal to a domestic manufacturer. We were fortunate to find a manufacturer that was willing to cooperate with our challenging proposals, and by building up experience together, we were able to develop the technical capabilities to produce a product like the OCW-SG1000ZE," says Sato.

　The case size is slightly larger than the S6000: the S6000's case is 42.5mm in diameter, while this model's is 43mm in diameter.

"The face is the most important part of this model. That's why we made it larger to make the face appear larger. The sapphire crystal is also different in cut and size (compared to previous models), and I think it's the most luxurious Oceanus ever made. The reason we used sapphire crystal is that when light hits the facets, it is diffused and reflects internally, creating a sparkle. It's interesting how the watch changes appearance in sunlight, coupled with the color of the vapor deposition. Sapphire crystal is also scratch-resistant, so another benefit to users is that it retains its beauty for a long time." (Mr. Sato)

　However, it must have been difficult to balance this Oceanus-like feel with the concept of "Zero to One."

"The theme colors for 'Zero to One' were black and gold. It was a promise made by all six brands (announced for the 50th anniversary). That's why we used black DLC coating on the titanium exterior. But we broke our promise and incorporated blue. It's Oceanus Blue, after all," said Sato with a grin. At first glance, it was hard to imagine anyone other than Hitachi using blue.

"This sapphire crystal bezel is colored with black vapor deposition. However, the inner vertical wall is also colored blue with blue sputtering. This double coloring achieves a color that is 'black yet polarized blue.' The dial is also a navy color that is close to black, and is midnight blue. The appearance of black actually changes depending on the color of the base. With a black base, it is a deep black. With a blue base, it becomes a tight black."

　The midnight blue dial is made of brass and is plated, but it is first made blue by dry plating with blue IP, and then a black coating is applied on top, which is a time-consuming process. Finally, it is smoothed out with a coating wrap. "It takes time and effort to get that little bit of blue."

Casio's development approach makes us look forward to the future

The OCW-SG1000ZE, developed with a "creating something from nothing" approach, has reached a new level of sole-source radio-controlled solar watches. The high-quality dial made possible by Gallium Tough Solar and the intricate details inherited from the Oceanus are sure to appeal to watch enthusiasts.

　Of course, this model will not be the end goal for Oceanus.

"When you think of Oceanus, you might imagine customers in their 30s or 40s. In fact, we have customers who are even older, and people who bought watches from this brand in the 2000s are now trading up to current models. That's why I think an important value of Oceanus is that it provides surprise and excitement to such Oceanus fans, those who empathize with the Oceanus worldview," said Sato, and there is no doubt that Oceanus will continue to show us "new horizons" that exceed our imagination.