Abstract: The present application discloses a focal length adjustment method, device, apparatus and computer readable storage medium for AR glasses, the method includes: receiving a focal length adjustment command, and displaying a preset circle with a preset reference radius through a display module; capturing a first image of the preset circle in an eye of a wearer of the AR glasses through the camera to obtain a first captured image, and determining a first imaging radius of the preset circle in the first image according to the first captured image; determining target diopter of the eye of the wearer according to the preset reference radius and the first imaging radius; and determining a target deflecting angle of the display module according to the target diopter, and adjusting the display module according to the target deflecting angle.

Abstract: Implementations of this specification provide query optimization methods, apparatuses, and systems for secure multi-party databases. In an implementation, a method includes: receiving a current query associated with a plurality of target database of a multi-party database system, generating a plurality of execution plans for the current query, determining, for each execution plan, a respective cost computation formula of a plurality of cost computation values for computing an execution cost of jointly executing the execution plan by the plurality of target databases, receiving a secure computation result from each of a plurality of query engines corresponding to the plurality of target databases, and determining an optimal execution plan having a lowest cost value in the plurality of cost computation formulas based on the secure computation result.

Abstract: The present disclosure provides a display substrate, a preparing method thereof, and a display device. The display substrate includes: a base substrate including a spacing region; a plurality of light-emitting device groups on the base substrate, any two adjacent light-emitting device groups of the plurality of light-emitting device groups being spaced apart from each other by the spacing region; and a light-shielding layer on the base substrate. The light-shielding layer covers the plurality of light-emitting device groups and fills the spacing region, a first portion of the light-shielding layer covering the plurality of light-emitting device groups has a first thickness, a second portion of the light-shielding layer filling the spacing region has a second thickness, the first thickness is less than the second thickness.

Abstract: A display calibration method for a head-mounted device is disclosed in the present disclosure. The method comprises: controlling a camera to take a first eye image when a user wears the head-mounted device; determining a human eye gazing position according to the first eye image, wherein the human eye gazing position is a position of a human eye gazing point on the head-mounted device; retrieving a preset gazing position of the head-mounted device and calculating positional deviation information of the preset gazing position compared to the human eye gazing position; and adjusting a screen display position of the head-mounted device according to the positional deviation information.

Abstract: The present disclosure provides a display baseplate and a display apparatus. The display baseplate includes a substrate, light emitter groups on the substrate, a light-adjusting structure on the substrate, and a diffusion structure on the substrate. The light emitter groups include light emitters. Chambers are disposed in the light-adjusting structure, and one light emitter group is located in one chamber; the orthographic projections of the chambers in which the light emitter groups are located on the substrate have basically same area; the light-adjusting structure is configured to converge light emitted by the light emitters to increase an amount of light of positive view angle of the display baseplate. The diffusion structure is at least partially located at a side of the light emitters away from the substrate, and configured to diffuse the light emitted by the light emitters.

Abstract: The present application discloses a focal length adjustment method, device, apparatus and computer readable storage medium for AR glasses, the method includes: receiving a focal length adjustment command, and displaying a preset circle with a preset reference radius through a display module; capturing a first image of the preset circle in an eye of a wearer of the AR glasses through the camera to obtain a first captured image, and determining a first imaging radius of the preset circle in the first image according to the first captured image; determining target diopter of the eye of the wearer according to the preset reference radius and the first imaging radius; and determining a target deflecting angle of the display module according to the target diopter, and adjusting the display module according to the target deflecting angle.