Abstract: A projection apparatus configured to project an image frame onto a projected plane is provided. The projection apparatus includes an image source, a projection lens, a time-of-flight ranging sensor (ToF ranging sensor), and a controller. The image source is configured to emit an image beam. The projection lens is configured to project the image beam onto the projected plane to form the image frame. The ToF ranging sensor is configured to measure a distance from the projected plane. The controller is configured to set a sampling range of the ToF ranging sensor and obtain a plurality sets of distance information of measured points on the projected plane by moving the sampling range of the ToF ranging sensor, and adjust a focal distance of the projection lens according to the sets of distance information through the controller. A projecting method is also provided.

Abstract: A control method for an optical device includes a detector detecting a current position of a lens, a processor calculating a distance between the current position and a target position, the processor determining whether the current position is within a predetermined range according to the distance, and the processor controlling a driving device to move the lens into an allowable range according to whether the current position is within the predetermined range. The predetermined range and the allowable range are corresponding to the target position.

Abstract: A control method for an optical device includes a detector detecting a current position of a lens, a processor calculating a distance between the current position and a target position, the processor determining whether the current position is within a predetermined range according to the distance, and the processor controlling a driving device to move the lens into an allowable range according to whether the current position is within the predetermined range. The predetermined range and the allowable range are corresponding to the target position.

Abstract: A printing method for printing an input image. Firstly, a halftone mask is generated. The input image is transformed into a halftone image through the halftone mask. The halftone image is then output for printing. The halftone mask is an array of N elements, and the following steps generate the halftone mask. An initial array of N elements is first provided. Thereafter, a first value is selectively assigned to an element in the initial array to generate a first array. The second to the Nth arrays are then recursively generated based on the first array in the following steps. A minimum energy element in an Ith array is first determined. An (I+1)th value is then assigned to the minimum energy element to generate an (I+1)th array, wherein I denotes 2 to N?1.

Abstract: The invention discloses an independent scanning apparatus and an independent scanning method. The independent scanning apparatus of the invention includes a casing, a sheet-feeding mechanism, a scanning device, a store module, and a processing module. The casing includes an inlet and an outlet. The sheet-feeding mechanism is disposed in the casing for transporting an object through the inlet and the outlet. The scanning device is disposed in the casing for scanning the object. The processing module is disposed in the casing and electrically connected to the sheet-feeding mechanism, the scanning device and the store module.

Abstract: A printing method for printing an input image. Firstly, a halftone mask is generated. The input image is transformed into a halftone image through the halftone mask. The halftone image is then output for printing. The halftone mask is an array of N elements, and the following steps generate the halftone mask. An initial array of N elements is first provided. Thereafter, a first value is selectively assigned to an element in the initial array to generate a first array. The second to the Nth arrays are then recursively generated based on the first array in the following steps. A minimum energy element in an Ith array is first determined. An (I+1)th value is then assigned to the minimum energy element to generate an (I+1)th array, wherein I denotes 2 to N?1.