JP2005313482A - Color thermal printer and method of color thermal printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a time period for optical fixing more by always carrying out the optical fixing by an adequate light quantity. <P>SOLUTION: This color thermal printer 2 comprises a use condition acquisition section 41 for acquiring a use condition of a fixing device 22, a use history acquisition section 44 for acquiring a use history of the fixing device 22, and a system controller 20 for setting beforehand a light quantity Ls of a fixing light in a sub-fixing process based on the use history so as not to increase a waste fixing time period nor cause insufficient fixing in the sub-fixing process. The system controller 20 sets the light quantity Ls according to at least one of a judgment result of a use condition judgment circuit 40 for judging whether or not the use condition is of cold start and a comparison result of a comparison circuit 43 for comparing the light quantity Ls set by the previous sub-fixing process with a minimum light quantity Lsmin of the fixing light in the previous sub-fixing process. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a heat-sensitive color developing layer for coloring at least cyan, magenta, and yellow is sequentially formed. The yellow and magenta heat-sensitive color developing layers are each provided with a color developing ability when irradiated with fixing light having a specific wavelength range. Using a color thermosensitive recording paper with a light-fixing property that eliminates light, and thermally transporting each thermosensitive coloring layer with a thermal head while transporting the color thermosensitive recording paper, the yellow and magenta thermosensitive coloring layers that have been thermally recorded In contrast, the present invention relates to a color thermal printer and a color thermal printing method in which fixing is performed by irradiating fixing light with a fixing device.

  2. Description of the Related Art Color thermal printers that print full-color prints using color thermal recording paper in which thermal color-developing layers that develop colors of cyan, magenta, and yellow are sequentially provided on a support are widely used. In this color thermal printer, thermal recording is performed on each thermal coloring layer with a thermal head in which a plurality of heating elements are arranged in a line while conveying the color thermal recording paper. In addition, after thermal recording on the yellow and magenta thermosensitive coloring layers, the color thermosensitive recording paper is irradiated with ultraviolet rays by a fixing device so that the previous thermosensitive coloring layer does not develop color during thermal recording on the next thermosensitive coloring layer. It has been fixed.

  In the above color thermal printer, for the purpose of shortening the photofixing time, during thermal recording on the magenta thermosensitive coloring layer, the fixing speed of the color thermosensitive recording paper is fixed and the magenta thermosensitive coloring layer is photofixed. Light is applied to the magenta thermosensitive coloring layer by dividing it into a main fixing process and a sub-fixing process that adjusts the conveyance speed of the color thermosensitive recording paper and performs light fixing on the magenta thermosensitive coloring layer before thermal recording on the cyan thermosensitive coloring layer. There is one that performs fixing (see Patent Document 1).

  In the color thermal printer described in Patent Document 1, in the main fixing step, light fixing and thermal recording are performed while conveying the color thermal recording paper in the direction of the fixing device, and in the sub fixing step, the main fixing step is performed. Light fixing is performed while conveying color thermal recording paper in the opposite direction. In addition, the minimum illuminance during the main fixing process is detected, and it is determined whether or not the sub-fixing process can be performed, and color heat sensitivity in the sub-fixing process is determined according to the initial illuminance in the sub-fixing process and the minimum illuminance. The recording paper transport speed is set.

JP 2000-177157 A

  By the way, with the downsizing and simplification of the device configuration, after feeding the color thermal recording paper until the rear end of the image recording area of the color thermal recording paper reaches the heating element array, the color thermal recording paper is reversed in the opposite direction. A color thermal printer has been devised in which thermal recording is performed while being conveyed, and then color thermal recording paper is conveyed in the direction of feeding again and optical fixing is performed.

  In the color thermal printer as described above, when the light fixing of the magenta thermal coloring layer is divided into the main fixing step and the sub-fixing step, the color thermal recording paper is used before the thermal recording on the cyan thermal coloring layer in the main fixing step. In the sub-fixing step, light fixing may be performed at a constant conveyance speed during thermal recording on the cyan thermosensitive coloring layer. In this case, in the main fixing process, the color thermal recording paper is conveyed in the first feeding direction while carrying out light fixing, and in the secondary fixing process, the color thermal recording paper is conveyed in the opposite direction to that in the main fixing process. Then, light fixing and thermal recording are performed.

  When the main fixing process and the sub-fixing process are performed in this way, as in the color thermal printer described in Patent Document 1, the sub-fixing process is performed according to the initial illuminance in the sub-fixing process and the minimum illuminance in the main fixing process. By setting the color thermal recording paper conveyance speed at, it becomes impossible to control the shortage in the main fixing process so as to make up for the shortage in the main fixing process. For this reason, it is necessary to predict the amount of fixing light in the sub-fixing step and adjust the conveyance speed of the color thermal recording paper in the main fixing step accordingly.

  In the color thermal printer as described above, conventionally, the light amount of the fixing light in the sub-fixing step is a uniform value, for example, the initial value of the light amount in the main fixing step (0 after the ultraviolet lamp as the light source of the fixing device starts to light). The conveyance speed of the color thermal recording paper in the main fixing step is set as 80% of the value after .5 seconds). However, as shown in FIG. 6, the light quantity characteristics of the ultraviolet lamp are affected by temperature (the initial light quantity at the start is low at low temperatures, the initial light quantity is high at high temperatures, but the light quantity decreases with time). If the light intensity of the fixing light in the fixing process is set to a uniform value, there will be a difference between the amount of light actually output from the ultraviolet lamp in the sub-fixing process, and there will be an increase in wasted fixing time or insufficient fixing in the sub-fixing process. There was a risk of becoming.

  The present invention has been made in view of the above problems, and can always perform light fixing with an appropriate light amount without increasing useless fixing time or insufficient fixing, and maintaining light fixing performance while maintaining light fixing performance. It is an object of the present invention to provide a color thermal printer and a color thermal printing method capable of further shortening the fixing time.

  In order to achieve the above-mentioned object, the present invention is provided with a heat-sensitive color developing layer for producing at least cyan, magenta, and yellow in order, and each of yellow and magenta heat-sensitive color developing layers has a fixing light having a specific wavelength range. Using color thermal recording paper with photofixability that loses its color development ability when irradiated with heat, thermal recording is performed on each thermal coloring layer with a thermal head while transporting this color thermal recording paper. A color thermal printer that performs light fixing on a used yellow and magenta thermosensitive coloring layer by irradiating the fixing light with a fixing device, wherein the fixing device performs the above-described heat recording on the cyan thermosensitive coloring layer. The main fixing process for fixing the magenta thermosensitive coloring layer by adjusting the conveying speed of the color thermosensitive recording paper, and the magenta sensitivity at the same conveying speed during thermal recording on the cyan thermosensitive coloring layer. It is divided into a sub-fixing step of performing light fixing on the color developing layer, performing light fixing on the magenta thermosensitive coloring layer, a use state acquiring unit for acquiring the use state of the fixing device, and a use history of the fixing device. Based on at least one of the usage history acquisition unit for acquiring, the usage state, and at least one of the usage history, an increase or fixing of useless fixing time in the sub-fixing step. In order not to be insufficient, the light amount Ls of the fixing light in the sub-fixing step is set in advance, and the integrated light amount ΔLs of the fixing light in the sub-fixing step is obtained and obtained from the set light amount Ls and the conveyance speed. By calculating the difference between the integrated light amount ΔLs and the total integrated light amount ΔLa necessary for fixing the magenta thermosensitive coloring layer, the integrated light amount ΔLm of the fixing light in the main fixing step is obtained. And a control means for adjusting the conveyance speed in the main fixing step according to the integrated light quantity ΔLm.

  The use state acquisition unit is configured to use a first temperature sensor that measures the temperature of the thermal head, a second temperature sensor that measures the temperature in the printer body, and measurement results of the first and second temperature sensors. The usage history determining unit includes an illuminance sensor that measures the amount of the fixing light, the light amount Ls set in the previous sub-fixing step, and the previous time. A storage unit that stores the minimum light amount Lsmin of the fixing light in the sub-fixing step; and a comparison unit that compares the light amount Ls stored in the storage unit with the minimum light amount Lsmin. It is preferable that the light quantity Ls is set according to at least one of the determination result of the use state determination unit and the comparison result of the comparison unit.

  In the present invention, a heat-sensitive color developing layer for coloring at least cyan, magenta, and yellow is sequentially formed. When the fixing light having a specific wavelength range is irradiated to the yellow and magenta heat-sensitive color developing layers, respectively. Using a color thermal recording paper with photofixability that loses its color development ability, thermal recording is performed on each thermal coloring layer with a thermal head while the color thermal recording paper is being transported. A color thermal printing method in which the fixing layer is irradiated with the fixing light to fix the color developing layer, and the color thermal recording paper conveyance speed is adjusted before thermal recording on the cyan thermal coloring layer. A main fixing process for performing light fixing on the magenta thermosensitive coloring layer, and a sub-fixing process for performing light fixing on the magenta thermosensitive coloring layer at a constant conveyance speed during thermal recording on the cyan thermosensitive coloring layer. And fixing the magenta thermosensitive coloring layer with the fixing device, and obtaining at least one of the usage state of the fixing device and the usage history of the fixing device, Based on at least one of the usage histories, the light amount Ls of the fixing light in the sub-fixing step is set in advance so as not to increase useless fixing time or insufficient fixing in the sub-fixing step. The integrated light amount ΔLs of the fixing light in the sub-fixing step is obtained from the set light amount Ls and the conveyance speed, and the difference between the obtained integrated light amount ΔLs and the total integrated light amount ΔLa necessary for fixing the magenta thermosensitive coloring layer is obtained. By obtaining the integrated light amount ΔLm of the fixing light in the main fixing step, the conveyance speed in the main fixing step is adjusted according to the integrated light amount ΔLm. And performing.

  The temperature in the thermal head and the printer main body is measured, the use state is determined based on the measurement results, the amount of the fixing light is measured, and the temperature set in the previous sub-fixing step is measured. The light amount Ls and the minimum light amount Lsmin of the fixing light in the previous sub-fixing step are stored, the stored light amount Ls and the minimum light amount Lsmin are compared, and the determination result of the use state, and the It is preferable that the light amount Ls is set according to at least one of the comparison results between the light amount Ls and the minimum light amount Lsmin.

  According to the color thermal printer and the color thermal printing method of the present invention, before the thermal recording on the cyan thermosensitive coloring layer, the main fixing step of adjusting the conveyance speed of the color thermosensitive recording paper and performing photofixing on the magenta thermosensitive coloring layer; In the thermal recording on the cyan thermosensitive coloring layer, the fixing speed is used to fix the magenta thermosensitive coloring layer to the magenta thermosensitive coloring layer at a constant conveyance speed. The status acquisition unit and the usage history acquisition unit acquire at least one of the usage status of the fixing device and the usage history of the fixing device, and based on at least one of the usage status and the usage history. Thus, the light amount Ls of the fixing light in the sub-fixing step is set in advance so that the fixing time is not increased or insufficiently fixed in the sub-fixing step. The fixing light integrated light amount ΔLs in the main fixing step is obtained by obtaining the integrated light amount ΔLs of the fixing light in the fixing process and taking the difference between the calculated integrated light amount ΔLs and the total integrated light amount ΔLa required for fixing the magenta thermosensitive coloring layer. In accordance with this integrated light quantity ΔLm, the control means adjusts the conveyance speed in the main fixing process, so that it is possible to always perform light fixing with an appropriate light quantity without increasing useless fixing time or insufficient fixing. In addition, it is possible to further shorten the light fixing time while maintaining the light fixing performance.

  In FIG. 1, a color thermal printer 2 to which the present invention is applied uses a long color thermal recording paper (hereinafter simply referred to as recording paper) 10 as a recording material. The recording paper 10 is set in the color thermal printer 2 in the form of a recording paper roll 11 wound in a roll shape.

  In FIG. 2, the recording paper 10 has a structure in which a cyan thermosensitive coloring layer 31, a magenta thermosensitive coloring layer 32, a yellow thermosensitive coloring layer 33, and a protective layer 34 are sequentially provided on a support 30 as is well known. ing. The yellow thermosensitive coloring layer 33 which is the uppermost layer has the highest thermal sensitivity and develops yellow with a small amount of heat energy. The cyan thermosensitive coloring layer 31 which is the lowermost layer has the lowest thermal sensitivity and develops cyan with large thermal energy.

  The yellow thermosensitive coloring layer 33 loses its coloring ability when irradiated with near ultraviolet rays of 420 nm. The magenta thermosensitive coloring layer 32 develops magenta with intermediate thermal energy between the yellow thermosensitive coloring layer 33 and the cyan thermosensitive coloring layer 31 and loses its coloring ability when irradiated with ultraviolet rays of 365 nm. For example, a recording paper having a four-layer structure provided with a black thermosensitive coloring layer may be used.

  In FIG. 1, a paper feed roller 13 rotated by a conveyance motor 12 is in contact with the outer peripheral surface of the recording paper roll 11. The carry motor 12 is a stepping motor and is driven by drive pulses input from the motor driver 14. When the paper feed roller 13 rotates counterclockwise in the figure, the recording paper roll 11 rotates clockwise in the figure, and the recording paper 10 is sent out from the recording paper roll 11. When the paper supply roller 13 rotates clockwise in the figure, the recording paper roll 11 rotates counterclockwise in the figure, and the recording paper 10 is rewound onto the recording paper roll 11.

  The recording paper 10 sent out from the recording paper roll 11 is sent into a conveyance path formed by a guide (not shown). In this transport path, a transport roller pair 15 is disposed that sandwiches and transports the recording paper 10. The conveyance roller pair 15 includes a capstan roller 15a rotated by the conveyance motor 12 and a pinch roller 15b pressed against the capstan roller 15a, and reciprocally conveys the recording paper 10 in the A direction and the B direction in the figure. .

  A thermal head 16 that records an image line by line in the width direction (main scanning direction) of the recording paper 10 on the recording paper 10 conveyed in the A direction on the downstream side of the conveyance roller pair 15 in the A direction, A platen roller 17 disposed on the opposite side across the transport path is provided so as to face the thermal head 16. A heating element array 19 in which a plurality of heating elements are arranged in a line is provided on the surface of the thermal head 16 facing the recording paper 10 of the head substrate 18. The heating element array 19 generates heat based on the drive data input from the system controller 20 to the head driver 21, and causes each of the thermosensitive coloring layers 31 to 33 of the recording paper 10 to color.

  The thermal head 16 is movable in a direction perpendicular to the conveyance path, and is biased in a direction in which it is pressed against the platen roller 17 by a spring (not shown). When the recording paper 10 is fed and discharged, the thermal head 16 is moved upward by a shift mechanism (not shown) composed of a cam, a solenoid, etc., and the holding of the recording paper 10 with the platen roller 17 is released. The The platen roller 17 is driven and rotated in accordance with the conveyance of the recording paper 10 to stabilize the contact state between the recording paper 10 and the heating element array 19.

  On the downstream side in the A direction of the thermal head 16, a fixing device 22 is disposed so as to face the recording surface of the recording paper 10. The fixing unit 22 emits near-ultraviolet light having an emission peak of 420 nm to fix the yellow thermosensitive coloring layer 33 and magenta fixing the magenta thermosensitive coloring layer 32 by emitting ultraviolet light having an emission peak of 365 nm. Fixing light source 22b, and a reflector 22c that reflects light from these light sources 22a and 22b toward the recording paper 10. Each of the light sources 22a and 22b includes an ultraviolet lamp and is driven by a lamp driver 23.

  A cutter 24 for cutting the recording paper 10 into a predetermined print size is disposed on the downstream side of the fixing device 22 in the A direction. Further, on the downstream side in the A direction of the cutter 24, a paper discharge port 25 for discharging the recording paper 10 on which an image has been recorded to the outside is provided.

  The system controller 20 controls lighting of the light sources 22 a and 22 b via the lamp driver 23. The yellow fixing light source 22 a is dimmed so that the fixing light does not affect the magenta thermosensitive coloring layer 32. Alternatively, the yellow fixing light source 22a emits full light, and the conveyance speed of the recording paper 10 is adjusted when the yellow thermosensitive coloring layer 33 is light-fixed. On the other hand, the magenta fixing light source 22b emits full light without performing dimming control.

  In the color thermal printer 2, after the recording paper 10 is sent out in the A direction until the rear end of the image recording area of the recording paper 10 reaches the heating element array 19, the yellow thermal coloring layer 33 is conveyed while conveying the recording paper 10 in the B direction. Then, the recording paper 10 was conveyed at high speed in the A direction until the rear end of the image recording area of the recording paper 10 reached the end of the fixing light source 22a for the fixing unit 22 on the cutter 24 side. After that, the yellow fixing light source 22a is turned on and the recording paper 10 is conveyed in the B direction at the same speed as the shutter mechanism (not shown) provided to prevent the next image recording area from being exposed to light. The yellow thermosensitive coloring layer 33 is photofixed.

  After the yellow thermosensitive coloring layer 33 is light-fixed, the yellow fixing light source 22a is turned off, and the recording paper 10 is conveyed at a high speed in the A direction until the rear end of the image recording area of the recording paper 10 reaches the heating element array 19. Thermal recording is performed on the magenta thermosensitive coloring layer 32 while conveying the recording paper 10 in the B direction again. Next, after the shutter mechanism is retracted from the magenta fixing light source 22b and moved just below the yellow fixing light source 22a, the magenta fixing light source 22b is turned on, the recording paper 10 is conveyed in the A direction, and the heat is Photofixing is performed on the recorded magenta thermosensitive coloring layer 32 (main fixing step).

  After the main fixing of the magenta thermosensitive coloring layer 32, thermal recording is performed on the cyan thermosensitive coloring layer 31 while conveying the recording paper 10 in the B direction again. At this time, the magenta fixing light source 22b is not turned off, and the light fixing to the magenta thermosensitive coloring layer 32 is continued (sub-fixing step). In this case as well, the shutter mechanism described above is located directly below the yellow fixing light source 22a, and does not hinder the light fixing to the magenta thermosensitive coloring layer 32 by the magenta fixing light source 22b.

  In the main fixing process, the system controller 20 adjusts the conveyance speed of the recording paper 10 by controlling the driving of the conveyance motor 12 via the motor driver 14. On the other hand, in the sub-fixing step, the recording speed of the recording paper 10 is made constant because thermal recording is performed on the cyan thermosensitive coloring layer 31.

  A first temperature sensor 26 for measuring the temperature of the thermal head 16 is embedded in the head substrate 18 of the thermal head 16. A second temperature sensor 27 for measuring the temperature in the color thermal printer 2 is disposed in the vicinity of the paper discharge port 25. Further, illuminance sensors 28a and 28b for measuring the amount of fixing light emitted from the light sources 22a and 22b are disposed above the reflectors 22c of the light sources 22a and 22b of the fixing device 22, respectively.

  As shown in FIG. 3, a use state determination circuit 40 is connected to the first and second temperature sensors 26 and 27. The use state determination circuit 40 determines the use state of the color thermal printer 2 based on the measurement results of the first and second temperature sensors 26 and 27. Specifically, the difference between the measurement result of the first temperature sensor 26 (temperature of the thermal head 16) and the measurement result of the second temperature sensor 27 (temperature in the color thermal printer 2) is calculated, and this difference is, for example, 5 If the measurement result of the second temperature sensor 27 is within normal temperature (25 ° C.) or less within the temperature range, it is determined that the use state is a cold start under an environment of normal temperature or less. The use state determination circuit 40 transmits the determination result to the system controller 20. The first and second temperature sensors 26 and 27 and the use state determination circuit 40 constitute a use state acquisition unit 41.

  A memory 42 is connected to the illuminance sensors 28a and 28b. Further, a comparison circuit 43 is connected to the memory 42. The memory 42 has an initial light amount value in the main fixing process (a value 0.5 seconds after the magenta light source 22b starts to light), and a light amount Ls (described later) set by the system controller 20 in the previous sub-fixing process. ), And the minimum light amount Lsmin of the fixing light in the previous sub-fixing step is stored. The comparison circuit 43 compares the light amount Ls stored in the memory 42 with the minimum light amount Lsmin. The comparison circuit 43 transmits this comparison result to the system controller 20. The illuminance sensors 28a and 28b, the memory 42, and the comparison circuit 43 constitute a usage history acquisition unit 44.

  The system controller 20 increases or fixes useless fixing time in the sub-fixing process based on at least one of the usage state and usage history acquired by the usage state acquisition unit 41 and the usage history acquisition unit 44. The light quantity Ls of the fixing light in the sub-fixing process is set in advance so as not to become insufficient. That is, when the use state determination circuit 40 of the use state acquisition unit 41 determines that the use state of the color thermal printer 2 is a cold start in an environment of room temperature or lower, the system controller 20 determines the fixing light in the sub-fixing step. The light amount Ls is set to an initial value (= 100%) of the light amount in the main fixing process. On the other hand, when it is determined that it is not a cold start, the light amount Ls is set to 80% of the initial value of the light amount in the main fixing step.

  The system controller 20 obtains the integrated light amount ΔLs of the fixing light in the sub-fixing step from the set light amount Ls and the conveyance speed (known) of the recording paper 10 in the sub-fixing step. Then, by taking the difference between the obtained integrated light amount ΔLs and the total integrated light amount ΔLa (known) necessary for fixing the magenta thermosensitive coloring layer 32, the integrated light amount ΔLm (= ΔLa−ΔLs) of the fixing light in the main fixing process is obtained. Ask.

  The system controller 20 adjusts the conveyance speed in the main fixing process according to the obtained integrated light quantity ΔLm. That is, when the calculated integrated light amount ΔLm is larger than the reference value, the conveyance speed of the recording paper 10 is delayed, and conversely, when it is small, the conveyance motor 12 is driven via the motor driver 14 so as to increase the conveyance speed. To control. Actually, a data table representing the relationship between the obtained integrated light amount ΔLm and the conveyance speed of the recording paper 10 is stored in advance, and the above adjustment is performed with reference to this data table.

  Further, when the comparison circuit 43 of the usage history acquisition unit 44 determines that the minimum light amount Lsmin of the fixing light in the previous sub-fixing step is larger than the light amount Ls set in the previous sub-fixing step, the system controller 20 The amount of light Ls set in the previous sub-fixing step is set to an extra 5% with respect to the amount of light divided by the initial value of the amount of light in the previous main fixing step, and the increased light amount ratio is set to the amount of light in the next main fixing step. Is multiplied by the initial value to obtain the light quantity Ls in the next sub-fixing step. On the other hand, when it is determined that the minimum light quantity Lsmin of the fixing light in the previous sub-fixing process is smaller than the light quantity Ls set in the previous sub-fixing process, the discount is set to 5% with respect to the light quantity ratio described above. By multiplying the discounted light amount ratio by the initial value of the light amount in the next main fixing step, the light amount Ls in the next sub-fixing step is obtained.

  Similarly to the case where the light quantity Ls is set based on the use state, the system controller 20 obtains the integrated light quantity ΔLm of the fixing light in the main fixing process, and adjusts the conveyance speed in the main fixing process according to the obtained integrated light quantity ΔLm. I do. In this case, the setting of the light amount Ls of the fixing light in the sub-fixing step is stored in the memory 42 with the light amount Ls set in the previous sub-fixing step and the minimum light amount Lsmin of the fixing light in the previous sub-fixing step. This is performed for the second and subsequent prints.

  Next, the operation of the color thermal printer 2 having the above configuration will be described. When the image recording start operation is executed, the feed roller 13 is rotated counterclockwise by the forward rotation of the transport motor 12, and the recording paper 10 is sent out from the recording paper roll 11 in the A direction. The leading edge of the recording paper 10 moves in the conveyance path, is nipped by the conveyance roller pair 15, and is further conveyed downstream in the A direction.

  When the rear end of the image recording area of the recording paper 10 reaches the heating element array 19, the rotation of the transport motor 12 is temporarily stopped. Next, the thermal head 16 is lowered by the shift mechanism, and the recording paper 10 is sandwiched between the platen roller 17. In this state, the conveyance motor 12 is driven in the reverse direction, and the yellow thermosensitive coloring layer of the recording paper 10 is generated by the heating element array 19 that generates heat based on the driving data input to the head driver 21 while the recording paper 10 is conveyed in the B direction. A yellow image is recorded at 33.

  When the recording of the yellow image is completed, the recording paper 10 is conveyed at high speed in the A direction until the rear end of the image recording area of the recording paper 10 reaches the end of the fixing light source 22a for the fixing device 22 on the cutter 24 side. Thereafter, the yellow fixing light source 22a is turned on. Then, while the recording paper 10 is conveyed in the B direction at the same speed as the shutter mechanism, the heat-recorded yellow thermosensitive coloring layer 33 is light-fixed. At this time, the thermal head 16 is raised by the shift mechanism, and the holding of the recording paper 10 by the platen roller 17 is released.

  After the yellow thermosensitive coloring layer 33 is light-fixed, the yellow fixing light source 22a is turned off, and the recording paper 10 is conveyed at high speed in the A direction until the rear end of the image recording area of the recording paper 10 reaches the heating element array 19. Next, the transport motor 12 is driven in reverse again, and thermal recording is performed on the magenta thermosensitive coloring layer 32 while the recording paper 10 is transported in the B direction. At this time, similarly to the yellow image recording, the thermal head 16 is lowered by the shift mechanism, and the recording paper 10 is held between the platen roller 17 and the thermal head 16.

  When the recording of the magenta image is completed, the shutter mechanism is retracted from the magenta fixing light source 22b and moved directly below the yellow fixing light source 22a, and then the magenta fixing light source 22b is turned on. Then, the transport motor 12 is driven to rotate in the normal direction again, and the recording paper 10 is transported in the A direction. As a main fixing step, the heat-recorded magenta thermosensitive coloring layer 32 is light-fixed. At this time, the drive of the conveyance motor 12 is controlled by the system controller 20 and the conveyance speed of the recording paper 10 is adjusted.

  After the main fixing of the magenta thermosensitive coloring layer 32, the conveyance motor 12 is driven again in the reverse direction, and thermal recording is performed on the cyan thermosensitive coloring layer 31 while the recording paper 10 is conveyed in the B direction. At this time, the magenta fixing light source 22b is not turned off, and the light fixing to the magenta thermosensitive coloring layer 32 is continued as a sub-fixing step. Further, the system controller 20 controls the driving of the transport motor 12 so that the transport speed of the recording paper 10 is kept constant. Furthermore, at this time, the shutter mechanism remains just below the yellow fixing light source 22a.

  After recording the cyan image and sub-fixing the magenta thermosensitive coloring layer 32, the recording paper 10 is conveyed in the A direction by the conveying roller pair 15, cut to a predetermined print size by the cutter 24, and then externally discharged from the paper discharge port 25. To be discharged.

  As shown in FIG. 4, when the first print after the color thermal printer 2 is turned on or after an image recording start instruction is made, the magenta fixing light source 22b is used at the start of the main fixing process. The initial value of the amount of fixing light emitted from the light is measured by the illuminance sensor 28 b and stored in the memory 42. Further, the temperature of the thermal head 16 and the temperature in the color thermal printer 2 are measured by the first and second temperature sensors 26 and 27. Based on the measurement results of the first and second temperature sensors 26 and 27, the use state determination circuit 40 determines whether or not the use state of the color thermal printer 2 is a cold start in an environment of room temperature or less. Determined.

  When the use state determination circuit 40 determines that the use state of the color thermal printer 2 is a cold start in an environment of room temperature or lower, the light amount Ls of the fixing light in the sub-fixing process is the initial value ( = 100%). On the other hand, when it is determined that it is not a cold start, the light amount Ls is set to 80% of the initial value of the light amount in the main fixing step.

  In the system controller 20, the integrated light amount ΔLs of fixing light in the sub-fixing step is obtained from the set light amount Ls and the conveyance speed of the recording paper 10 in the sub-fixing step. Then, the difference between the obtained integrated light amount ΔLs and the total integrated light amount ΔLa necessary for fixing the magenta thermosensitive coloring layer 32 is obtained, and the integrated light amount ΔLm of the fixing light in the main fixing step is obtained.

  Next, the conveyance speed in the main fixing process is adjusted with reference to a data table that represents the relationship between the obtained integrated light amount ΔLm and the conveyance speed of the recording paper 10. In the sub-fixing step, the minimum light amount Lsmin is measured by the illuminance sensor 28 and stored in the memory 42 together with the set light amount Ls.

  As shown in FIG. 5, when the second and subsequent prints are created, the light amount Ls set in the previous sub-fixing step stored in the memory 42 and the minimum light amount of fixing light in the previous sub-fixing step. Lsmin is read by the comparison circuit 43, and the comparison circuit 43 compares the light amount Ls with the minimum light amount Lsmin.

  When the comparison circuit 43 determines that the minimum light amount Lsmin of the fixing light in the previous sub-fixing step is larger than the light amount Ls set in the previous sub-fixing step, the light amount Ls set in the previous sub-fixing step. Is set to 5% over the light intensity ratio divided by the initial light intensity value in the previous main fixing process, and the next sub-fixing is performed by multiplying the increased light intensity ratio by the initial light intensity value in the next main fixing process. A light amount Ls in the process is obtained. On the other hand, when it is determined that the minimum light amount Lsmin of the fixing light in the previous sub-fixing step is smaller than the light amount Ls set in the previous sub-fixing step, the light amount Ls set in the previous sub-fixing step is changed to the previous light amount Ls. The light quantity ratio divided by the initial value of the light quantity in the main fixing process is set at 5% discount, and the light quantity ratio in the next sub-fixing process is set by multiplying the discounted light quantity ratio by the initial light quantity value in the next main fixing process. Ls is determined.

  In the system controller 20, the integrated light amount ΔLm of the fixing light in the main fixing step is obtained in the same manner as when the light amount Ls is set based on the use state, and the conveyance speed of the main fixing step is determined according to the obtained integrated light amount ΔLm. Adjustments are made. In the sub-fixing step, the minimum light amount Lsmin is measured by the illuminance sensor 28 and stored in the memory 42 together with the set light amount Ls. In the color thermal printer 2, the above process is repeatedly executed.

  As described above, the light amount Ls of the fixing light in the sub-fixing step is set based on the use state and the use history of the color thermal printer 2, and the integrated light amount ΔLm of the fixing light in the main fixing step is obtained based on this. Since the conveyance speed of the recording paper 10 in the main fixing process is adjusted, the actual light quantity is larger than the light quantity set at the cold start as in the conventional method in which the light quantity of the fixing light in the sub-fixing process is a uniform value. Therefore, there is no increase in useless fixing time, and in other cases, the actual light quantity is less than the light quantity set reversely, and fixing is not insufficient. Therefore, it is possible to always perform light fixing with an appropriate amount of light, and it is possible to shorten the light fixing time and thus the printing time while maintaining the light fixing performance.

  In the above embodiment, when creating the first print, the light amount Ls of the fixing light in the sub-fixing process is set based on the usage state, and when creating the second and subsequent prints, the usage history is recorded. Although the light quantity Ls is set based on this, the light quantity Ls may be set based on the use state even when the second and subsequent prints are created. Also, when creating the first print, the prescribed light amount Ls is set without referring to the use state, and when creating the second and subsequent prints, the light amount Ls is set based on the use history. May be. In other words, the light amount Ls in the sub-fixing process may be set based on at least one of the usage state and the usage history.

  In the above embodiment, the values used when setting the light quantity Ls (80% of the initial value of the light quantity in the main fixing process, 5% of the light quantity ratio, discount, etc.) are the specifications of the color thermal printer 2. It is possible to change appropriately according to.

1 is a schematic diagram illustrating a configuration of a color thermal printer to which the present invention is applied. It is a fragmentary sectional view which shows the structure of a color thermal recording paper. It is a block diagram which shows the structure of a use condition acquisition part and a use log | history acquisition part. It is a flowchart which shows the process sequence of the color thermal printer in the case of producing the 1st print. It is a flowchart which shows the process sequence of the color thermal printer in the case of producing the print after the 2nd sheet. It is a graph which shows the temperature dependence of the light quantity of an ultraviolet lamp.

Explanation of symbols

2 Color thermal printer 10 Color thermal recording paper (recording paper)
DESCRIPTION OF SYMBOLS 12 Conveyance motor 15 Conveyance roller pair 16 Thermal head 19 Heating element array 20 System controller 22 Fixing device 22a Fixing light source for yellow 22b Fixing light source for magenta 26, 27 First and second temperature sensors 28a, 28b Illuminance sensor 31 Cyan thermosensitive coloring layer 32 Magenta thermosensitive coloring layer 33 Yellow thermosensitive coloring layer 40 Usage state determination circuit 41 Usage state acquisition unit 42 Memory 43 Comparison circuit 44 Usage history acquisition unit

Claims (4)

A thermosensitive color-developing layer is formed in sequence at least in cyan, magenta, and yellow, and the yellow and magenta thermosensitive color-developing layers lose their color developing ability when irradiated with fixing light with their specific wavelength ranges. Using color thermal recording paper with fixing properties,
While transporting this color thermal recording paper, thermal recording is performed on each thermal coloring layer with a thermal head,
A color thermal printer that performs photofixing by irradiating the fixing light to a yellow and magenta thermosensitive coloring layer that has been thermally recorded by a fixing device,
The fixing device includes a main fixing step of adjusting the conveyance speed of the color thermosensitive recording paper and performing photofixing on the magenta thermosensitive coloring layer before thermal recording on the cyan thermosensitive coloring layer;
During the thermal recording on the cyan thermosensitive coloring layer, it is divided into a sub-fixing step in which the conveying speed is fixed and the magenta thermosensitive coloring layer is photofixed, and the magenta thermosensitive coloring layer is photofixed,
At least one of a usage state acquisition unit for acquiring a usage state of the fixing unit and a usage history acquisition unit for acquiring a usage history of the fixing unit;
Based on at least one of the use state and the use history, the light amount Ls of the fixing light in the sub-fixing step is prevented so that the useless fixing time is not increased or insufficiently fixed in the sub-fixing step. Set in advance,
From the set light amount Ls and the conveyance speed, an integrated light amount ΔLs of the fixing light in the sub-fixing step is obtained,
By calculating the difference between the obtained integrated light amount ΔLs and the total integrated light amount ΔLa required for fixing the magenta thermosensitive coloring layer, the integrated light amount ΔLm of the fixing light in the main fixing step is obtained.
A color thermal printer comprising: a control unit that adjusts the conveyance speed in the main fixing step in accordance with the integrated light amount ΔLm. The use state acquisition unit includes a first temperature sensor that measures the temperature of the thermal head, a second temperature sensor that measures the temperature in the printer body, and the measurement results of the first and second temperature sensors based on the measurement results of the first and second temperature sensors. A use state determining means for determining the use state;
The usage history acquisition unit stores an illuminance sensor that measures the light amount of the fixing light, the light amount Ls set in the previous sub-fixing step, and the minimum light amount Lsmin of the fixing light in the previous sub-fixing step. Means, and comparison means for comparing the light quantity Ls stored in the storage means with the minimum light quantity Lsmin,
The said control means sets the said light quantity Ls according to at least any one among the determination result of the said use state determination means, and the comparison result of the said comparison means, The said light quantity Ls is characterized by the above-mentioned. Color thermal printer. A thermosensitive color-development layer that colors at least cyan, magenta, and yellow is sequentially formed, and the yellow and magenta thermosensitive color-development layers lose their color development ability when irradiated with fixing light having specific wavelength ranges. Using color thermal recording paper with fixing properties,
While transporting this color thermal recording paper, thermal recording is performed on each thermal coloring layer with a thermal head,
A color thermal printing method in which the fixing is performed by irradiating the fixing light to the yellow and magenta thermosensitive coloring layer that has been thermally recorded,
A main fixing step of adjusting the conveyance speed of the color thermal recording paper and performing photofixing on the magenta thermal coloring layer before thermal recording on the cyan thermal coloring layer;
During thermal recording on the cyan thermosensitive coloring layer, the fixing speed is divided into a sub-fixing step in which the magenta thermosensitive coloring layer is photofixed at a constant conveyance speed, and the magenta thermosensitive coloring layer is photofixed by the fixing device.
Obtaining at least one of the usage state of the fixing device and the usage history of the fixing device;
Based on at least one of the usage state and the usage history, the light amount Ls of the fixing light in the sub-fixing step is prevented so that the useless fixing time is not increased or insufficiently fixed in the sub-fixing step. Set in advance,
From the set light amount Ls and the conveyance speed, an integrated light amount ΔLs of the fixing light in the sub-fixing step is obtained,
By calculating the difference between the obtained integrated light amount ΔLs and the total integrated light amount ΔLa required for fixing the magenta thermosensitive coloring layer, the integrated light amount ΔLm of the fixing light in the main fixing step is obtained.
A color thermal printing method, wherein the conveyance speed is adjusted in the main fixing step in accordance with the integrated light quantity ΔLm. Measure the temperature in the thermal head and the printer body, determine the use state based on these measurement results,
The light quantity of the fixing light is measured, the light quantity Ls set in the previous sub-fixing process, and the minimum light quantity Lsmin of the fixing light in the previous sub-fixing process are stored, and the stored light quantity Ls is stored. And the minimum light quantity Lsmin,
The light amount Ls is set according to at least one of the determination result of the use state and the comparison result between the light amount Ls and the minimum light amount Lsmin. Color thermal printing method.

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