Patent Description:
A technique has been provided in which an image is formed on a thermal medium having a color development layer that develops a color through heat. In such a technique, a photothermal conversion layer formed in a vicinity of the color development layer is irradiated with a laser beam to heat the color development layer. A device (laser recording device) for forming an image on a thermal medium sets irradiation parameters such as a wavelength or an intensity of a laser beam to be applied based on medium parameters such as a photothermal conversion efficiency of the photothermal conversion layer.

Conventionally, a laser recording device requires an input of medium parameters for each thermal medium through an operation by a user or the like.

<CIT> discloses a recording medium including a base material; a first color developing layer that is laminated on the base material, and absorbs light having a given wavelength to develop a color; a photothermal conversion layer that is laminated closer to an incident side of the light than the first color developing layer, transmits visible light, and absorbs the light for photothermal conversion; and a second color developing layer that is laminated closer to the incident side of the light than the first color developing layer, transmits visible light and the light, and develops a color by heat converted by the photothermal conversion layer.

<CIT> discloses a thermal color forming type card product that has a printing data recording part having the printing data related to the heat-printing condition of the thermal color forming layer recorded thereon and a reader/writer has a printing data reading part and a printing condition adjusting part adjusting the heat-printing condition of the thermal color forming layer on the basis of the printing data read by the reading part.

To solve the problem described above, a laser recording device is provided in which medium parameters can be acquired efficiently.

According to one embodiment, a laser recording device has the features of claim <NUM>.

A recording system according to the embodiment prints an image on a thermal medium. The recording system irradiates the thermal medium with a laser beam to thereby heat the thermal medium. The recording system controls a position, intensity, etc. of the laser beam to be applied to print an image on the thermal medium.

<FIG> illustrates a configuration example of a recording system <NUM> according to the embodiment. As shown in <FIG>, the recording system <NUM> includes a thermal medium <NUM>, a laser recording device <NUM>, etc..

The thermal medium <NUM> is a medium on which an image is printed through a laser beam. Here, the thermal medium <NUM> is formed into a card shape. For example, the thermal medium <NUM> is used as identification. For example, the thermal medium <NUM> is used as identification such as a driver's license, an individual number card, or an insurance card. The thermal medium <NUM> may be used as a credit card or a cash card. The application of the thermal medium <NUM> is not limited to a specific configuration. The thermal medium <NUM> will be described in detail later.

The laser recording device <NUM> irradiates the thermal medium <NUM> with a laser beam to print an image. The thermal medium <NUM> is inserted into the laser recording device <NUM> from the outside. The laser recording device <NUM> applies a laser beam to print a predetermined image on the inserted thermal medium <NUM>. The laser recording device <NUM> discharges, to the outside, the thermal medium <NUM> on which the predetermined image is printed. The laser recording device <NUM> will be described in detail later.

Next, the thermal medium <NUM> will be described.

<FIG> shows a surface of the thermal medium <NUM> on which the image is formed by the laser recording device <NUM>.

As shown in <FIG>, the thermal medium <NUM> includes a full-color image forming area ARC in which a full-color image such as an identification photograph is recorded, and a monochrome image forming area ARM in which specific information such as ID information, a name, and an issue date is recorded in monochrome.

The thermal medium <NUM> further includes a storage mechanism <NUM>. The storage mechanism <NUM> will be described in detail later.

<FIG> is a cross-sectional view of a configuration example of the thermal medium <NUM>. <FIG> is an explanatory diagram of a thickness and a thermal conductivity ratio of the thermal medium <NUM>.

The thermal medium <NUM> is a medium in which at least one color development layer that develops a color by heat and a protective layer that protects color development of the at least one color development layer are laminated. The color development layer has light transmission properties before color development.

As a specific example, the thermal medium <NUM> has a structure in which, as shown in <FIG>, an adhesive layer <NUM>, a photothermal conversion layer <NUM>, a high-temperature thermal Y color development layer 14Y, an intermediate layer <NUM>, a medium-temperature thermal M color development layer <NUM>, an intermediate layer <NUM>, a low-temperature thermal C color development layer 14C, a light-absorption color development layer <NUM>, an adhesive layer <NUM>, and a protective functional layer <NUM> are laminated in order on a base material <NUM>. The light-absorption color development layer <NUM> is provided as a black color development layer. The high-temperature thermal Y color development layer 14Y, the medium-temperature thermal M color development layer <NUM>, the low-temperature thermal C color development layer 14C, and the light-absorption color development layer <NUM> constitute a color development layer group <NUM>. The protective functional layer <NUM> forms a front surface (surface on which an image is formed). The base material <NUM> forms a back surface.

The thermal medium <NUM> may include a configuration as needed in addition to the configuration shown in <FIG>, or a specific configuration may be excluded from the thermal medium <NUM>.

The high-temperature thermal Y color development layer 14Y, the medium-temperature thermal M color development layer <NUM>, and the low-temperature thermal C color development layer 14C function as color development layers that develop yellow, magenta, and cyan, respectively.

The intermediate layers <NUM> and <NUM> each function as a heat insulating layer that adjusts the amount of heat transfer and reduces heat transfer.

The base material <NUM> holds the adhesive layer <NUM>, the photothermal conversion layer <NUM>, the high-temperature thermal Y color development layer 14Y, the intermediate layer <NUM>, the medium-temperature thermal M color development layer <NUM>, the intermediate layer <NUM>, the low-temperature thermal C color development layer 14C, the light-absorption color development layer <NUM>, the adhesive layer <NUM>, and the protective functional layer <NUM>.

The thickness of the base material <NUM> is set to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The photothermal conversion layer <NUM> absorbs recording light (recording laser light) of a given wavelength to perform photothermal conversion. The photothermal conversion layer <NUM> generates heat for causing at least any one of the high-temperature thermal Y color development layer 14Y, the medium-temperature thermal M color development layer <NUM>, or the low-temperature thermal C color development layer 14C to develop a color.

The thickness of the photothermal conversion layer <NUM> is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The adhesive layer <NUM> is a layer that holds the base material <NUM> and the photothermal conversion layer <NUM> while bonding them.

The thickness of the adhesive layer <NUM> is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The high-temperature thermal Y color development layer 14Y (first color development layer) is a layer containing a temperature-indicating material as a thermal material that develops yellow (first color) if its own temperature becomes equal to or higher than a first threshold temperature T1.

The thickness of the high-temperature thermal Y color development layer 14Y is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The medium-temperature thermal M color development layer <NUM> (second color development layer) is a layer containing a temperature-indicating material as a thermal material that develops magenta (second color) if its own temperature becomes equal to or higher than a second threshold temperature T2 (< T1).

The thickness of the medium-temperature thermal M color development layer <NUM> is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The low-temperature thermal C color development layer 14C (third color development layer) is a layer containing a temperature-indicating material as a thermal material that develops cyan (third color) if its own temperature becomes equal to or higher than a third threshold temperature T3 (< T2 < T1).

The thickness of the low-temperature thermal C color development layer 14C is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The intermediate layer <NUM> is a layer that provides a thermal barrier at the time of color development of the high-temperature thermal Y color development layer 14Y and reduces heat transfer from the low-temperature thermal C color development layer 14C side to the medium-temperature thermal M color development layer <NUM> and the low-temperature thermal C color development layer 14C.

The thickness of the intermediate layer <NUM> is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The intermediate layer <NUM> is a layer that provides a thermal barrier at the time of color development of the medium-temperature thermal M color development layer <NUM> and reduces heat transfer from the medium-temperature thermal M color development layer <NUM> side to the low-temperature thermal C color development layer 14C.

The light-absorption color development layer <NUM> is a layer including pigment particles and developing a color irreversibly by the pigment particles absorbing and carbonizing recording light.

The thickness of the light-absorption color development layer <NUM> is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

The adhesive layer <NUM> is a layer that holds the light-absorption color development layer <NUM> and the protective functional layer <NUM> while bonding them.

The protective functional layer <NUM> protects the adhesive layer <NUM>, the light-absorption color development layer <NUM>, the low-temperature thermal C color development layer 14C, the intermediate layer <NUM>, the medium-temperature thermal M color development layer <NUM>, the intermediate layer <NUM>, the high-temperature thermal Y color development layer 14Y, the photothermal conversion layer <NUM>, and the adhesive layer <NUM>. The protective functional layer <NUM> is a layer used for arrangement of anti-counterfeit items such as a hologram, a lenticular lens, a microarray lens, or an ultraviolet excitation type fluorescent ink, insertion of an internal protection item such as an ultraviolet cut layer, or both of these functions.

The protective functional layer <NUM> is preferably colorless and transparent since there is a need to visually check the color development of the color development layer group <NUM> formed under the protective functional layer <NUM>.

The thickness of the protective functional layer <NUM> is set to <NUM> to <NUM>, and the thermal conductivity ratio thereof is set to <NUM> to <NUM> W/m/K, for example.

Next, light absorption characteristics of the photothermal conversion layer <NUM> will be described.

<FIG> is an explanatory diagram of an example of the light absorption characteristics of the photothermal conversion layer <NUM>.

In <FIG>, the horizontal axis represents the wavelength of light. The vertical axis represents the absorption ratio of light (photothermal conversion efficiency). As shown in <FIG>, the photothermal conversion layer <NUM> has absorption characteristics having a peak at a wavelength λ (for example, λ = <NUM>) belonging to near infrared rays.

Meanwhile, the base material <NUM>, the adhesive layer <NUM>, the high-temperature thermal Y color development layer 14Y, the intermediate layer <NUM>, the medium-temperature thermal M color development layer <NUM>, the intermediate layer <NUM>, the low-temperature thermal C color development layer 14C, the adhesive layer <NUM>, and the protective functional layer <NUM> are each formed of a material that transmits light having a wavelength λ belonging to near infrared rays (near infrared light). This is because light having a wavelength λ that can be absorbed by the light-absorption color development layer <NUM> or the photothermal conversion layer <NUM> (near infrared light) is made to reach these layers. At least a part of the base material <NUM> may be formed of a material that transmits near infrared light.

Thus, if near infrared light having a wavelength λ (for example, λ = <NUM>) is incident from the base material <NUM> side, the incident near infrared light is transmitted through the respective layers in order from the base material <NUM> to the adhesive layer <NUM>, and is mostly absorbed by the photothermal conversion layer <NUM>. The incident near infrared light is photo-thermally converted by the photothermal conversion layer <NUM> to heat the high-temperature thermal Y color development layer 14Y, the medium-temperature thermal M color development layer <NUM>, or the low-temperature thermal C color development layer 14C to develop a color.

On the other hand, if recording light is incident from the protective functional layer <NUM> side, the incident recording light is transmitted through the respective layers in order from the protective functional layer <NUM> to the adhesive layer <NUM>, and is mostly absorbed by the light-absorption color development layer <NUM>. The incident recording light heats the light-absorption color development layer <NUM> to develop a color.

In the example of the thermal medium <NUM>, the high-temperature thermal Y color development layer 14Y and the photothermal conversion layer <NUM> are laminated as independent layers. As another example, by mixing a photothermal conversion material into the high-temperature thermal Y color development layer 14Y, the high-temperature thermal Y color development layer 14Y may serve as the photothermal conversion layer.

The photothermal conversion layer <NUM> and the light-absorption color development layer <NUM> may have different light absorption characteristics. For example, the photothermal conversion layer <NUM> may have absorption characteristics having a peak at a predetermined wavelength λ (for example, λ = <NUM>). The light-absorption color development layer <NUM> may have absorption characteristics having a peak at a different wavelength λ (for example, λ = <NUM>).

In this case, the laser irradiation mechanism <NUM> may irradiate the photothermal conversion layer <NUM> and the light-absorption color development layer <NUM> with recording laser light having different wavelengths from the protective functional layer <NUM> side. The light-absorption color development layer <NUM> is made of a material that transmits recording laser light (light having the same wavelength as that of the recording laser light) to the photothermal conversion layer <NUM>. The base material <NUM> may not have transmission properties.

The laser irradiation mechanism <NUM> may irradiate the photothermal conversion layer <NUM> and the light-absorption color development layer <NUM> with recording laser light having different wavelengths from the base material <NUM> side. The photothermal conversion layer <NUM> is made of a material that transmits recording laser light (light having the same wavelength as that of the recording laser light) to the light-absorption color development layer <NUM>. The protective functional layer <NUM> may not have transmission properties.

Next, the storage mechanism <NUM> will be described.

The storage mechanism <NUM> stores information related to parameters (medium parameters) of the thermal medium <NUM>. Here, the storage mechanism <NUM> stores medium parameters.

A medium parameter is used for the laser recording device <NUM> to apply the recording laser light. That is, the medium parameter is used for the laser recording device <NUM> to determine a wavelength or intensity, etc. of the recording laser light.

The medium parameter includes a photothermal conversion efficiency of the photothermal conversion layer <NUM> at a predetermined wavelength. The medium parameter may indicate a photothermal conversion efficiency of the photothermal conversion layer <NUM> at a plurality of wavelengths. The medium parameter may include a parameter with which the laser recording device <NUM> can calculate the photothermal conversion efficiency of the photothermal conversion layer <NUM>.

The medium parameter may include an intensity of the recording laser light. For example, the medium parameter may include a pulse width, period, or duty ratio, etc. output by the laser recording device <NUM> for applying the recording laser light.

The medium parameter may include a distance from the front or back surface of the thermal medium <NUM> to the photothermal conversion layer <NUM> or the light-absorption color development layer <NUM>.

The configuration of the medium parameter is not limited to a specific configuration.

The storage mechanism <NUM> stores the medium parameter in a state of being readable by the laser recording device <NUM>.

For example, the storage mechanism <NUM> is a code obtained by encoding the medium parameter according to a predetermined algorithm. In this case, the storage mechanism <NUM> is printed on the front or back surface of the thermal medium <NUM>. For example, the storage mechanism <NUM> is a bar code or a twodimensional code (for example, a QR code (registered trademark)).

The storage mechanism <NUM> may be a character string, a numerical value, a symbol, or a combination thereof indicating the medium parameter. In this case, the storage mechanism <NUM> is printed on the front or back surface of the thermal medium <NUM>.

The storage mechanism <NUM> may be an IC chip that stores the medium parameter. In this case, the storage mechanism <NUM> includes a communication unit for communicating with the laser recording device <NUM> in a wireless or wired manner, a control unit for transmitting the medium parameter to the laser recording device <NUM> through the communication unit, etc. The storage mechanism <NUM> may be formed inside the protective functional layer <NUM>, etc. The storage mechanism <NUM> may be formed in the protective functional layer <NUM>, etc. so that the communication unit is exposed to the outside.

The storage mechanism <NUM> may also be a magnetic stripe encoded with the medium parameter.

Note that the configuration of the storage mechanism <NUM> is not limited to a specific configuration.

Next, the laser recording device <NUM> will be described.

<FIG> shows a configuration example of the laser recording device <NUM>. As shown in <FIG>, the laser recording device <NUM> includes a processor <NUM>, a memory <NUM>, a conveyance mechanism <NUM>, a reading mechanism <NUM>, a position detection mechanism <NUM>, a height detection mechanism <NUM>, a laser irradiation mechanism <NUM>, an irradiation position control mechanism <NUM>, a camera <NUM>, a communication unit <NUM>, etc. The processor <NUM>, the memory <NUM>, the conveyance mechanism <NUM>, the reading mechanism <NUM>, the position detection mechanism <NUM>, the height detection mechanism <NUM>, the laser irradiation mechanism <NUM>, the irradiation position control mechanism <NUM>, the camera <NUM>, and the communication unit <NUM> are connected to each other via a data bus or an interface, etc..

The laser recording device <NUM> may include a configuration as needed in addition to the configuration shown in <FIG>, or a specific configuration may be excluded from the laser recording device <NUM>.

The processor <NUM> controls the entire operation of the laser recording device <NUM>. For example, the processor <NUM> controls the laser irradiation mechanism <NUM>, etc. to irradiate the thermal medium <NUM> with the recording laser light.

For example, the processor <NUM> includes a CPU, etc. The processor <NUM> may include an application specific integrated circuit (ASIC), etc. The processor <NUM> may include a field programmable gate array (FPGA), etc..

The memory <NUM> stores various types of data. For example, the memory <NUM> functions as a ROM, RAM, and NVM.

For example, the memory <NUM> stores a control program, control data, etc. The control program and the control data are incorporated in advance according to the specifications of the laser recording device <NUM>. For example, the control program is a program, etc. supporting functions realized by the laser recording device <NUM>.

The memory <NUM> temporarily stores data, etc. being processed by the processor <NUM>. The memory <NUM> may store data necessary for executing the application program, an execution result of the application program, etc..

The conveyance mechanism <NUM> feeds the thermal medium <NUM> under the control of the processor <NUM>. The conveyance mechanism <NUM> receives an insertion of the thermal medium <NUM> from the outside. The conveyance mechanism <NUM> conveys the inserted thermal medium <NUM> to each unit of the laser recording device <NUM>. The conveyance mechanism <NUM> discharges the thermal medium <NUM> to the outside.

For example, the conveyance mechanism <NUM> includes a guide rail, a conveyance roller, etc..

The reading mechanism <NUM> reads the medium parameter from the storage mechanism <NUM> of the thermal medium <NUM>. The reading mechanism <NUM> transmits the read medium parameter to the processor <NUM>. The reading mechanism <NUM> has a configuration corresponding to the configuration of the storage mechanism <NUM>.

For example, if the storage mechanism <NUM> is a code, the reading mechanism <NUM> includes a camera that captures an image of the storage mechanism <NUM>, a processor that decodes the captured code to acquire a medium parameter, etc..

If the storage mechanism <NUM> is a character string, etc., the reading mechanism <NUM> includes a camera that captures an image of the storage mechanism <NUM>, a processor that recognizes characters such as the captured character string to acquire a medium parameter, etc..

If the storage mechanism <NUM> is an IC chip, the reading mechanism <NUM> includes a reader that transmits and receives data to and from the IC chip, etc..

If the storage mechanism <NUM> is a magnetic stripe, the reading mechanism <NUM> includes a magnetic head that reads the magnetic stripe, etc..

Note that the reading mechanism <NUM> may include a mechanism corresponding to each configuration of the storage mechanism <NUM>. The configuration of the reading mechanism <NUM> is not limited to a specific configuration.

The position detection mechanism <NUM> detects a position of the thermal medium <NUM> when the laser irradiation mechanism <NUM> applies the recording laser light. The position detection mechanism <NUM> transmits the detected position to the processor <NUM>. For example, the position detection mechanism <NUM> detects the position of the end portion of the thermal medium <NUM>. For example, the position detection mechanism <NUM> includes a detection plate that detects contact with the end portion, a camera that captures an image of the thermal medium <NUM> or a laser scanner, etc. The configuration of the position detection mechanism <NUM> is not limited to a specific configuration.

The height detection mechanism <NUM> detects a height of the thermal medium <NUM> (a distance in the thickness direction of the thermal medium <NUM>) when the laser irradiation mechanism <NUM> applies the recording laser light. The height detection mechanism <NUM> transmits the detected height to the processor <NUM>.

For example, the height detection mechanism <NUM> acquires heights at three points of the thermal medium <NUM> using a laser beam, etc. The height detection mechanism <NUM> specifies a plane including a surface of the thermal medium <NUM> from the acquired heights at the three points. The height detection mechanism <NUM> acquires a height at each point of the thermal medium <NUM> based on the specified plane.

The laser irradiation mechanism <NUM> irradiates the thermal medium <NUM> with recording laser light under the control of the processor <NUM>. The laser irradiation mechanism <NUM> sets a wavelength of the recording laser light under the control of the processor <NUM>. The laser irradiation mechanism <NUM> sets an intensity and irradiation timing of the recording laser light under the control of the processor <NUM>.

For example, the laser irradiation mechanism <NUM> includes an irradiation unit (for example, a laser diode) that outputs recording laser light, a lens that diffuses or converges the recording laser light output by the irradiation unit, etc..

The irradiation position control mechanism <NUM> controls a position of the thermal medium <NUM> to be irradiated with the recording laser light under the control of the processor <NUM>.

For example, the irradiation position control mechanism <NUM> controls a traveling direction of the recording laser light radiated by the laser irradiation mechanism <NUM>. For example, the irradiation position control mechanism <NUM> includes a galvanometer mirror or a polygon mirror, etc..

The irradiation position control mechanism <NUM> may control the position of the thermal medium <NUM>. For example, the irradiation position control mechanism <NUM> includes a stage that movably supports the thermal medium <NUM>, etc..

The irradiation position control mechanism <NUM> may control both the traveling direction of the recording laser light and the position of the thermal medium <NUM>.

The camera <NUM> captures an image of the thermal medium <NUM> under the control of the processor <NUM>. The camera <NUM> transmits the captured image to the processor <NUM>. The camera <NUM> is installed so as to capture an image of the thermal medium <NUM> from the upper side to the lower side.

The communication unit <NUM> is an interface for transmitting and receiving data to and from an external device. For example, the communication unit <NUM> supports a local area network (LAN) connection. For example, the communication unit <NUM> may support universal serial bus (USB) connection.

Next, functions realized by the laser recording device <NUM> will be described. The functions realized by the processor <NUM> are realized by the processor <NUM> executing a program stored in the internal memory or the memory <NUM>, etc..

First, the processor <NUM> has a function of acquiring data (recording data) for generating an image (print image) to be printed on the thermal medium <NUM>.

For example, the recording data may include image information such as a face photograph, and specific information such as ID information, a name, and an issue date. For example, the recording data is data related to identification such as a driver's license, an individual number card, or an insurance card. The recording data is data related to a credit card or a cash card, etc..

For example, the processor <NUM> acquires the recording data from the external device via the communication unit <NUM>. The processor <NUM> may acquire the recording data based on an operator's operation. The method by which the processor <NUM> acquires the recording data is not limited to a specific method.

Next, the processor <NUM> has a function of acquiring, by using the reading mechanism <NUM>, the medium parameter from the storage mechanism <NUM> of the thermal medium <NUM>.

The processor <NUM> feeds, by using the conveyance mechanism <NUM>, the thermal medium <NUM>. The processor <NUM> conveys, by using the conveyance mechanism <NUM>, the thermal medium <NUM> to a position where the reading mechanism <NUM> can read the storage mechanism <NUM>. Upon conveying the thermal medium <NUM> to this position, the processor <NUM> acquires, by using the reading mechanism <NUM>, the medium parameter from the storage mechanism <NUM> of the thermal medium <NUM>.

The processor <NUM> has a function of determining whether an image can be printed on the thermal medium <NUM> based on the acquired medium parameter.

For example, the processor <NUM> specifies a wavelength of recording laser light for printing an image on the thermal medium <NUM> based on the medium parameter. For example, the processor <NUM> specifies, as a wavelength of the recording laser light, a wavelength at which the photothermal conversion efficiency exceeds a predetermined threshold value.

The processor <NUM> determines whether the laser irradiation mechanism <NUM> can apply light having the specified wavelength. Upon determining that the laser irradiation mechanism <NUM> can apply light having the specified wavelength, the processor <NUM> determines that an image can be printed on the thermal medium <NUM>. Upon determining that the laser irradiation mechanism <NUM> cannot apply light having the specified wavelength, the processor <NUM> determines that an image cannot be printed on the thermal medium <NUM>.

Upon determining that an image cannot be printed on the thermal medium <NUM>, the processor <NUM> outputs an error. In this case, the processor <NUM> may discharge the thermal medium <NUM> to the outside using the conveyance mechanism <NUM>.

As for the method of determining by the processor <NUM> whether an image can be printed on the thermal medium <NUM> based on the acquired medium parameter, the method is not limited to a specific method.

The processor <NUM> has a function of setting a calibration area in the thermal medium <NUM>.

The calibration area is an area in which a color chart is printed to perform color calibration.

The processor <NUM> applies the recording data to a predetermined format to generate a print image.

The processor <NUM> conveys, using the conveyance mechanism <NUM>, the thermal medium <NUM> to a position where the laser irradiation mechanism <NUM> can apply the recording laser light. Upon conveying the thermal medium <NUM> to the position, the processor <NUM> specifies the position of the thermal medium <NUM> using the position detection mechanism <NUM>.

The processor <NUM> specifies a position (recording position) to be irradiated with the recording laser light based on the generated print image and the position of the thermal medium <NUM>.

Upon specifying the recording position, the processor <NUM> specifies, as a calibration area, an area where black is to be developed (an area where the color of the light-absorption color development layer <NUM> is developed) based on the recording position. For example, the processor <NUM> specifies, as a calibration area, an area having a rectangular shape of a predetermined size and in which black is to be developed.

The processor <NUM> has a function of performing color calibration by printing a color chart in the calibration area.

Upon setting the calibration area, the processor <NUM> acquires a height of the thermal medium <NUM> using the height detection mechanism <NUM>. Upon acquiring the height, the processor <NUM> sets various parameters (irradiation parameters) for the laser irradiation mechanism <NUM> based on the medium parameter, the height, etc..

The processor <NUM> sets a wavelength of the recording laser light as an irradiation parameter for the laser irradiation mechanism <NUM> based on the photothermal conversion efficiency, etc. included in the medium parameter. For example, the processor <NUM> sets, as a wavelength of the recording laser light, a wavelength at which the photothermal conversion efficiency exceeds a predetermined threshold value.

The processor <NUM> sets a focal distance of the recording laser light as an irradiation parameter for the laser irradiation mechanism <NUM> based on the height of the thermal medium <NUM>, etc. That is, the processor <NUM> sets a focal distance of the recording laser light so that the recording laser light is focused on the photothermal conversion layer <NUM> or the light-absorption color development layer <NUM>.

If the medium parameter includes a distance from the front or back surface of the thermal medium <NUM> to the photothermal conversion layer <NUM> or the light-absorption color development layer <NUM>, the processor <NUM> may set a focal point of the recording laser light based on the distance. The memory <NUM> may store in advance a distance from the front or back surface of the thermal medium <NUM> to the photothermal conversion layer <NUM> or the light-absorption color development layer <NUM>.

The processor <NUM> sets a focal depth of the recording laser light as an irradiation parameter for the laser irradiation mechanism <NUM> based on the height of the thermal medium <NUM>, etc. For example, the processor <NUM> calculates a flatness of the thermal medium <NUM> from the height of each part of the thermal medium <NUM>. Based on the calculated flatness, etc., the processor <NUM> sets a focal depth of the recording laser light so that the recording laser light is focused on the photothermal conversion layer <NUM>.

The content to be set for the laser irradiation mechanism <NUM> by the processor <NUM> is not limited to a specific configuration.

Upon setting the irradiation parameter for the laser irradiation mechanism <NUM>, the processor <NUM> prints a color chart in the calibration area using the laser irradiation mechanism <NUM>. That is, the processor <NUM> irradiates, using the laser irradiation mechanism <NUM>, the photothermal conversion layer <NUM> with the recording laser light.

The processor <NUM> irradiates the photothermal conversion layer <NUM> with the recording laser light so that the color development layer to develop a color is heated to a temperature at which a color is developed. For example, if yellow is to be developed, the processor <NUM> irradiates, using the laser irradiation mechanism <NUM>, the photothermal conversion layer <NUM> with the recording laser light so that the temperature of the high-temperature thermal Y color development layer 14Y is equal to or higher than the first threshold temperature T1. In this case, the processor <NUM> controls the irradiation time, intensity, etc., and applies the recording laser light so that the temperature of the medium-temperature thermal M color development layer <NUM> does not become equal to or higher than the second threshold temperature T2, and the temperature of the low-temperature thermal C color development layer 14C does not become equal to or higher than the third threshold temperature T3.

If magenta is to be developed, the processor <NUM> irradiates, using the laser irradiation mechanism <NUM>, the photothermal conversion layer <NUM> with the recording laser light so that the temperature of the medium-temperature thermal M color development layer <NUM> is equal to or higher than the second threshold temperature T2. In this case, the processor <NUM> controls the irradiation time, intensity, etc., and applies the recording laser light so that the temperature of the high-temperature thermal Y color development layer 14Y does not become equal to or higher than the first threshold temperature T1, and the temperature of the low-temperature thermal C color development layer 14C does not become equal to or higher than the third threshold temperature T3.

If cyan is to be developed, the processor <NUM> irradiates, using the laser irradiation mechanism <NUM>, the photothermal conversion layer <NUM> with the recording laser light so that the temperature of the low-temperature thermal C color development layer 14C is equal to or higher than the third threshold temperature T3. In this case, the processor <NUM> controls the irradiation time, intensity, etc., and applies the recording laser light so that the temperature of the high-temperature thermal Y color development layer 14Y does not become equal to or higher than the first threshold temperature T1, and the temperature of the medium-temperature thermal M color development layer <NUM> does not become equal to or higher than the second threshold temperature T2.

The processor <NUM> prints, using the irradiation position control mechanism <NUM> to control the irradiation position of the recording laser light, the color chart in the calibration area.

<FIG> shows an example of a color chart <NUM> to be printed by the processor <NUM>. The color chart <NUM> is an image obtained by printing yellow, magenta, and cyan at a plurality of densities.

As shown in <FIG>, the color chart <NUM> includes a pattern 41Y, a pattern <NUM>, and a pattern 41C.

The pattern 41Y is an image obtained by printing yellow at a plurality of densities. Here, the pattern 41Y is a set of images printed at four densities. In the pattern 41Y, the density decreases in order from the left image.

The pattern <NUM> is an image obtained by printing magenta at a plurality of densities. Similarly, the pattern <NUM> is a set of images printed at four densities. In the pattern <NUM>, the density decreases in order from the left image.

The pattern 41C is an image obtained by printing cyan at a plurality of densities. Similarly, the pattern 41C is a set of images printed at four densities. In the pattern 41C, the density decreases in order from the left image.

Note that the configuration of the color chart <NUM> is not limited to a specific configuration.

Upon printing the color chart in the calibration area, the processor <NUM> captures, using the camera <NUM>, an image of the calibration area on which the color chart is printed.

Upon capturing an image of the calibration area, the processor <NUM> performs calibration based on the captured image. For example, the processor <NUM> acquires a density of a color chart included in the captured image. If a predetermined color has a density differing from a desired density, the processor <NUM> corrects the irradiation parameter of the laser irradiation mechanism <NUM> so that the predetermined color has a desired density. The processor <NUM> may correct the irradiation parameter based on the temperature inside the laser irradiation mechanism <NUM>.

After correcting the setting of the laser irradiation mechanism <NUM>, the processor <NUM> may set another calibration area to print a color chart in the calibration area. The processor <NUM> may capture an image of the calibration area using the camera <NUM> to perform calibration again.

The processor <NUM> also has a function of printing a print image on the thermal medium <NUM>.

The processor <NUM> sets, using the irradiation position control mechanism <NUM>, the irradiation position based on the print image on the thermal medium <NUM>. Upon setting the irradiation position, the processor <NUM> irradiates the irradiation position with the recording laser light using the laser irradiation mechanism <NUM>. As a result, as described above, the photothermal conversion layer <NUM> at the irradiated position is heated, and the color development layer group <NUM> develops a color.

If yellow, magenta, or cyan is to be developed, the processor <NUM> irradiates the photothermal conversion layer <NUM> with the recording laser light from the base material <NUM> side. If black is to be developed, the processor <NUM> may irradiate the light-absorption color development layer <NUM> with the recording laser light from the protective functional layer <NUM> side.

The processor <NUM> applies the recording laser light in the same manner at each irradiation position based on the print image to print the print image on the thermal medium <NUM>.

Upon completion of printing, the processor <NUM> discharges the thermal medium <NUM> to the outside using the conveyance mechanism <NUM>. The processor <NUM> may put the thermal medium <NUM> on which the print image is printed into a predetermined container, etc..

Next, an operation example of the laser recording device <NUM> will be described.

<FIG> is a flowchart for explaining an operation example of the laser recording device <NUM>.

First, the processor <NUM> of the laser recording device <NUM> acquires recording data (S11). Upon acquiring the recording data, the processor <NUM> feeds the thermal medium <NUM> using the conveyance mechanism <NUM> (S12).

Upon feeding the thermal medium <NUM>, the processor <NUM> acquires a medium parameter from the storage mechanism <NUM> of the thermal medium <NUM> using the reading mechanism <NUM> (S13). Upon acquiring the medium parameter, the processor <NUM> determines whether an image can be printed on the thermal medium <NUM> based on the medium parameter (S14).

Upon determining that an image can be printed on the thermal medium <NUM> (S14, YES), the processor <NUM> acquires a position of the thermal medium <NUM> using the position detection mechanism <NUM> (S15). Upon acquiring the position of the thermal medium <NUM>, the processor <NUM> specifies a recording position based on the print image based on the recording data, the position of the thermal medium <NUM>, etc. (S16).

Upon specifying the recording position, the processor <NUM> sets a calibration area based on the recording position (S17). Upon setting the calibration area, the processor <NUM> acquires a height of the thermal medium <NUM> using the height detection mechanism <NUM> (S18).

Upon acquiring the height of the thermal medium <NUM>, the processor <NUM> sets an irradiation parameter for the laser irradiation mechanism <NUM> (S19). Upon setting the irradiation parameter for the laser irradiation mechanism <NUM>, the processor <NUM> prints a color chart in the calibration area (S20).

Upon printing the color chart, the processor <NUM> captures, using the camera <NUM>, an image including the calibration area (S21). Upon capturing the image, the processor <NUM> performs calibration based on the captured image, etc. (S22).

Upon performing calibration, the processor <NUM> prints an image based on the recording data on the thermal medium <NUM> using the laser irradiation mechanism <NUM> and the irradiation position control mechanism <NUM> (S23). Upon printing the image based on the recording data on the thermal medium <NUM>, the processor <NUM> deletes the recording data (S24).

Upon determining that the image cannot be printed on the thermal medium <NUM> (S14, NO) or deleting the recording data (S24), the processor <NUM> discharges the thermal medium <NUM> (S25).

Upon discharging the thermal medium <NUM>, the processor <NUM> terminates the operation.

The processor <NUM> may acquire the recording data upon determining that printing is possible on the thermal medium <NUM>.

The processor <NUM> may repeat S20 to S22 a plurality of times. In this case, the processor <NUM> may reset the calibration area to another area.

The reading mechanism <NUM>, the position detection mechanism <NUM>, and the camera <NUM> may be integrally configured. For example, the reading mechanism <NUM>, the position detection mechanism <NUM>, and the camera <NUM> may be configured by one camera.

The storage mechanism <NUM> may be a wireless tag such as radio frequency identification (RFID). In this case, the storage mechanism <NUM> stores an ID associated with the medium parameter. The storage mechanism <NUM> transmits the ID to the laser recording device <NUM>. The storage mechanism <NUM> is formed inside the protective functional layer <NUM>, or the like. The processor <NUM> acquires the ID from the wireless tag using the reading mechanism <NUM> that transmits and receives data to and from the wireless tag. The processor <NUM> acquires a medium parameter corresponding to the ID from the memory <NUM> or an external device.

Next, a modification of the thermal medium <NUM> will be described. Here, the thermal medium does not have the light-absorption color development layer <NUM>.

<FIG> is a cross-sectional view of a configuration example of a thermal medium <NUM>' that does not have the light-absorption color development layer <NUM>. In <FIG>, the thermal medium <NUM>' has a structure in which the low-temperature thermal C color development layer 14C, the intermediate layer <NUM>, the medium-temperature thermal M color development layer <NUM>, the intermediate layer <NUM>, the high-temperature thermal Y color development layer 14Y, the photothermal conversion layer <NUM>, the adhesive layer <NUM>, and the protective functional layer <NUM> are laminated in order on the base material <NUM>. In this case, the laser irradiation mechanism <NUM> applies the recording laser light from the protective functional layer <NUM>.

<FIG> is a cross-sectional view of another configuration example of a thermal medium <NUM>" that does not have the light-absorption color development layer <NUM>. In <FIG>, the thermal medium <NUM>" has a structure in which the adhesive layer <NUM>, the photothermal conversion layer <NUM>, the high-temperature thermal Y color development layer 14Y, the intermediate layer <NUM>, the medium-temperature thermal M color development layer <NUM>, the intermediate layer <NUM>, the low-temperature thermal C color development layer 14C, and the protective functional layer <NUM> are laminated in order on the base material <NUM>. In this case, the laser irradiation mechanism <NUM> irradiates the recording laser light from the protective functional layer <NUM>.

Even in the configuration examples shown in <FIG>, the base material <NUM> may not be transparent to visible light or near-infrared light.

The recording system configured as described above acquires a medium parameter from a thermal medium. The recording system sets an irradiation parameter related to laser light applied to the thermal medium based on the medium parameter. The recording system irradiates the thermal medium with laser light according to the set irradiation parameter to print an image on the thermal medium.

Claim 1:
A laser recording device (<NUM>), comprising:
a conveyance mechanism (<NUM>) configured to feed a thermal medium (<NUM>), the thermal medium (<NUM>) comprising: a photothermal conversion layer (<NUM>) that converts an applied laser beam into heat; a color development layer (14Y, <NUM>, 14C, <NUM>) that develops a color by the heat converted by the photothermal conversion layer (<NUM>); and characterised in that the laser recording device further comprises a storage mechanism that stores information related to a medium parameter including a photothermal conversion efficiency of the photothermal conversion layer (<NUM>);
a laser irradiation mechanism (<NUM>) configured to irradiate the thermal medium (<NUM>) with a laser beam;
a reading mechanism (<NUM>) configured to read the medium parameter;
a processor (<NUM>) configured to set an irradiation parameter related to laser beam irradiation based on the medium parameter, and irradiate the thermal medium (<NUM>) with the laser beam using the laser irradiation mechanism (<NUM>) in accordance with the set irradiation parameter; and
a camera (<NUM>) configured to capture an image of the thermal medium (<NUM>),
the processor (<NUM>) being configured to:
print a chart (<NUM>) on the thermal medium (<NUM>) using the laser irradiation mechanism (<NUM>);
capture an image including the chart (<NUM>) using the camera (<NUM>); and
correct the irradiation parameter using the image.