The invention describes a laser printing system (100) for illuminating an object (70) in a working plane (80). The object (70) moves relative to a print head (50) of the laser printing system (100). The print head (50) comprises a total number of laser modules (150), each laser module (150) comprises at least one laser array (110) of lasers (115). At least two of the laser modules (150) share an electrical power supply (20). The laser printing system (100) further comprises a controller (10) being adapted such that at maximum processing speed of the print head (50) only a predefined number of laser modules (150) can be driven at nominal electrical power, wherein the predefined number of laser modules (150) is smaller than the total number of laser modules. The invention further relates to a corresponding method of laser printing. The laser printing system and the method allow designing the laser printing system for, for example, only 20% of the total power which would be required to drive all lasers at nominal electrical power while having only slightly reduced processing speed.

The invention describes a laser printing system (100) for illuminating an object (70) in a working plane (80). The object (70) moves relative to a print head (50) of the laser printing system (100). The print head (50) comprises a total number of laser modules (150), each laser module (150) comprises at least one laser array (110) of lasers (115). At least two of the laser modules (150) share an electrical power supply (20). The laser printing system (100) further comprises a controller (10) being adapted such that at maximum processing speed of the print head (50) only a predefined number of laser modules (150) can be driven at nominal electrical power, wherein the predefined number of laser modules (150) is smaller than the total number of laser modules. The invention further relates to a corresponding method of laser printing. The laser printing system and the method allow designing the laser printing system for, for example, only 20% of the total power which would be required to drive all lasers at nominal electrical power while having only slightly reduced processing speed.

Method of controlling a laser marking matrix system, the matrix system comprising an NM matrix of lasers to produce the laser marking, the method comprising the sequential transformation of at least two images to be marked into a series of marking commands according to an NM matrix of dots, which comprises the following phases: division of a first image into a fixed portion and a variable portion, transformation of the fixed portion into a fixed matrix and the variable portion into a variable matrix, combination of said fixed and variable matrices, laser marking of the first image, processing of a second image, obtaining a new variable matrix which is added to the previous fixed matrix, producing a complete new matrix, laser marking of the second image.

A pulse signal is detected from an encoder signal of a rotary encoder. The detected pulse signal is used as a signal for controlling a light exposure timing of a line type light exposure head and is used for detecting a transport speed of an instant film. The light exposure head sequentially performs light exposure for a line image on the transported instant film in synchronization with each pulse signal detected from the encoder signal, and a density correction unit corrects an amount of light emission of the light exposure head depending on the transport speed of the instant film.

A light emitting device includes: a base that extends in one direction and that is formed of a metal block; plural light emitters that are disposed on a front surface side of the base so as to be displaced from each other in the one direction and in each of which plural light sources that are arranged in the one direction are supported by a support that extends in the one direction; and a protective member that is provided at an end portion of the base in a direction intersecting the one direction, that is disposed on a lateral side of the plural light emitters so as to extend in the one direction, and that protects the plural light emitters from outside.

There are provided a light irradiation device and a light irradiation system which are capable of correcting changes in optical power output. A light irradiation device includes: a substrate having an upper surface provided with a first recess and a second recess; a light-emitting element located in the first recess, the light-emitting element emitting ultraviolet light; and a detecting element located in the second recess, the detecting element being capable of detecting ultraviolet light.

There are provided a light irradiation device and a light irradiation system which are capable of correcting changes in optical power output. A light irradiation device includes: a substrate having an upper surface provided with a first recess and a second recess; a light-emitting element located in the first recess, the light-emitting element emitting ultraviolet light; and a detecting element located in the second recess, the detecting element being capable of detecting ultraviolet light.

A drive apparatus includes a light emitting device, a light receiving device configured to receive light emitted by the light emitting device, a comparison circuit configured to compare a light quantity of light detected by the light receiving device with a target value indicating a light quantity of light to be emitted by the light emitting device and generate a control signal corresponding to a comparison result, and a drive circuit configured to supply a drive signal corresponding to the control signal to the light emitting device. The drive circuit includes a gain changing switch configured to change, in accordance with the target value, a gain of the drive circuit.

A drive apparatus includes a light emitting device, a light receiving device configured to receive light emitted by the light emitting device, a comparison circuit configured to compare a light quantity of light detected by the light receiving device with a target value indicating a light quantity of light to be emitted by the light emitting device and generate a control signal corresponding to a comparison result, and a drive circuit configured to supply a drive signal corresponding to the control signal to the light emitting device. The drive circuit includes a gain changing switch configured to change, in accordance with the target value, a gain of the drive circuit.

An optical writing device includes: a light emitting substrate on which light emitting device groups obtained by grouping light emitting devices is arranged; a lens array including image forming lenses condensing light emitted from the light emitting devices on an image carrier; a first base material including the lens array; and a second base material including the light emitting substrate or the lens array, wherein the first and/or second base materials, each of which includes a joint formed in a joint part with the other member, is a transparent body, the joint includes a metal layer, an intermediate layer providing a peak of total transmissivity of the joint in a first wavelength band, and a marker for alignment, the first and second base materials are joined via the metal layer, and the light emitting devices emit light of a wavelength band out of the first wavelength band.