At CES 2023, Samsung showcased a series of concept foldable devices that could make their way to market in the future. One of the designs presented was a combination fold and slide-out design branded the Samsung Flex Hybrid as presented in a clip from a CNET video below.  

The design shown at CES was more like a mini-tablet that folds and expands. Yet Samsung is also considering a simpler single display that slides out that could attract those who want a larger display at times when the content calls for it, but not want a foldable smartphone for its bulk of creased display.

Last Thursday, the U.S. Patent Office published a Samsung patent application simply titled "Electronic Device including Flexible Display" that covers a slide out form factor as noted in their patent FIG. 1 below.

Samsung's patent FIG. 13 above is a block diagram illustrating an electronic device including a deformation sensor module.  

Technically, the patent is about a smartphone that may include a flexible display. For example, the flexible display may be disposed in an electronic device while at least an area thereof is curved, foldable and/or rollable. A display area visually exposed to an outer surface of the electronic device may be expanded or contracted.

The electronic device may sense an expansion level of a flexible display by maintaining a relative location with a magnetic sensor or recognizing an eye of a user who gazes at the display.

A slide-out smartphone could include: a flexible display that is configured to be deformable to a first state in which an exposed amount of a display area of the flexible display has a first size, and a second state in which the exposed amount of the display area is expanded in a first direction to have a second size that is larger than the first size; a deformable member including a liquid-state electrode, the deformable member being configured to deform in a length direction of the deformable member based on the flexible display transitioning between the first state and the second state; a deformation sensing circuit configured to sense a resistance component of the liquid-state electrode, the resistance component corresponding to an exposure degree of the display area; a connector member electrically connecting the deformable member and the deformation sensing circuit; a rigid member coupled to the deformable member and in which a portion of the connector member is disposed; and a fixed structure contacting a partial area of the rigid member, the fixed structure being configured to press a portion of the deformable member, and configured to restrict movement of the rigid member in a second direction that is opposite to the first direction.

The liquid-state electrode may include: a first electrode area that extends in the second direction; a second electrode area disposed in parallel to the first electrode area, and extending in the second direction; and a third electrode area connecting the first electrode area and the second electrode area, and having a length in a third direction that is substantially perpendicular to the first direction.

For more details on this invention, review Samsung's patent numbered US 20230008612 A1.

While an iPhone with a Slide-Out (scrollable or rollable) display is not a priority with Apple, they do have a couple of patents on this should it become a trend the public wants. You could review two of Apple's patents on this here: 01 and 02.