A display device is disclosed. The display device includes a base display panel, a back cover supporting a rear portion of the base display panel, sliding frames sliding with respect to the back cover, a driving unit configured to drive the sliding frames to slide, and a rollable display panel being extendable in response to the sliding of the sliding frames. The rollable display panel can be extended as needed by a user when widescreen images are displayed.

A gear assembly includes a first gear and a second gear. The first gear rotates about a first axis, and includes a first plurality of teeth and a first surface extending circumferentially and carried by the first plurality of teeth. The first surface is electrically conductive. The second gear rotates about a second axis and is operably connected to the first gear. The second gear includes an electrically conductive element, a second plurality of teeth, and a second surface extending circumferentially and carried by the second plurality of teeth. The second surface is electrically nonconductive. The electrically conductive element includes a plurality of feelers with each feeler projecting radially outward and into a respective tooth of the second plurality of teeth.

A gear assembly includes a first gear and a second gear. The first gear rotates about a first axis, and includes a first plurality of teeth and a first surface extending circumferentially and carried by the first plurality of teeth. The first surface is electrically conductive. The second gear rotates about a second axis and is operably connected to the first gear. The second gear includes an electrically conductive element, a second plurality of teeth, and a second surface extending circumferentially and carried by the second plurality of teeth. The second surface is electrically nonconductive. The electrically conductive element includes a plurality of feelers with each feeler projecting radially outward and into a respective tooth of the second plurality of teeth.

The present embodiments relate to a worm wheel of a steering system speed reducer, and provide a worm wheel of a steering system speed reducer, and a manufacturing method therefor, the worm wheel comprising: an external toothed part having a ring shape, external gear teeth provided on the outer peripheral side thereof, insertion grooves provided on the inner peripheral side thereof, and coupling holes provided on the upper surface and/or the lower surface thereof; an internal toothed part, which has a ring shape, is inserted into the external toothed part, has insertion protrusions provided on the outer peripheral side thereof, and has coupling protrusions provided at locations corresponding to the coupling holes; a hub to which a steering shaft is coupled; and a boss part provided between the outer peripheral side of the hub and the inner peripheral side of the external toothed part.

The present embodiments relate to a worm wheel of a steering system speed reducer, and provide a worm wheel of a steering system speed reducer, and a manufacturing method therefor, the worm wheel comprising: an external toothed part having a ring shape, external gear teeth provided on the outer peripheral side thereof, insertion grooves provided on the inner peripheral side thereof, and coupling holes provided on the upper surface and/or the lower surface thereof; an internal toothed part, which has a ring shape, is inserted into the external toothed part, has insertion protrusions provided on the outer peripheral side thereof, and has coupling protrusions provided at locations corresponding to the coupling holes; a hub to which a steering shaft is coupled; and a boss part provided between the outer peripheral side of the hub and the inner peripheral side of the external toothed part.

According to a steering column for a vehicle according to the present embodiments, a wide convenient space can be secured for a driver in a teles-in state by increasing a teles-stroke while securing an installation space for the steering column, the installation of the steering column is spatially convenient despite the increased teles-stroke, and a teles operation can be quickly performed without increasing the output of a motor, and thus a convenient space can be quickly secured for a driver without degraded noise performance.

A differential gear mechanism in which when a plurality of contact lines between a gear tooth and a pinion tooth is defined on either a tooth surface of the gear tooth of a crown gear or a tooth surface of the pinion tooth of a pinion gear at a predetermined angle around an axis of the pinion gear, and the plurality of contact lines and a center line of a pinion tooth bottom surface of the pinion gear are projected onto a plane, including an axis of a pair of the crown gears, around the axis of the pinion gear, the center line of the pinion tooth bottom surface projected onto the plane includes an inclined line passing through a range between two of the contact lines which are selected from the plurality of contact lines projected onto the plane and by which a contact ratio is 1.0 or higher.

A differential gear mechanism in which when a plurality of contact lines between a gear tooth and a pinion tooth is defined on either a tooth surface of the gear tooth of a crown gear or a tooth surface of the pinion tooth of a pinion gear at a predetermined angle around an axis of the pinion gear, and the plurality of contact lines and a center line of a pinion tooth bottom surface of the pinion gear are projected onto a plane, including an axis of a pair of the crown gears, around the axis of the pinion gear, the center line of the pinion tooth bottom surface projected onto the plane includes an inclined line passing through a range between two of the contact lines which are selected from the plurality of contact lines projected onto the plane and by which a contact ratio is 1.0 or higher.

A gear is provided that has excellent continuous moldability for practical use, and both high slidability and high durability. The provided gear is a molded resin constructed of a resin composition comprising a thermoplastic resin (A) and cellulose nanofibers (B) with an average fiber diameter of 1000 nm or smaller, and having a number average molecular weight of the thermoplastic resin (A) in the range of 10,000 to 150,000, wherein a sliding surface of the gear with another gear teeth has an arithmetic mean surface roughness Sa of 3.0 .Math.m or lower.

A gear is provided that has excellent continuous moldability for practical use, and both high slidability and high durability. The provided gear is a molded resin constructed of a resin composition comprising a thermoplastic resin (A) and cellulose nanofibers (B) with an average fiber diameter of 1000 nm or smaller, and having a number average molecular weight of the thermoplastic resin (A) in the range of 10,000 to 150,000, wherein a sliding surface of the gear with another gear teeth has an arithmetic mean surface roughness Sa of 3.0 .Math.m or lower.