JP2012181491A - Fixing device and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a heat-fixing process which can fix an image with desired glossiness using laser light.SOLUTION: A fixing device includes: a first laser light irradiation section 1 for irradiating an unfixed image TG with first laser light only for predetermined time tthat can fix an image; a second laser light irradiation section 2 for irradiating the unfixed image TG with second laser light for longer time tthan the irradiation time t; determination means 3 for determining glossiness required for the image of the unfixed image TG on a recording material 5; and control means 4 for controlling the first laser light irradiation section 1 and the second laser light irradiation section 2 based on the glossiness which has been determined by the determination means 3 so that at least irradiation energy of the second laser light irradiation section 2 is changed.

Description

  The present invention relates to a fixing device and an image forming apparatus using the same.

As conventional fixing devices, for example, those described in Patent Documents 1 and 2 are already known.
In Patent Document 1, a laser device is a semiconductor laser, a condensing optical system is a lens array having a lens unit corresponding to each semiconductor laser, and a laser beam emitted from the semiconductor laser is placed on a recording paper by the lens array. The light is condensed and thereby an unfixed toner image is fixed.
Patent Document 2 discloses that a plurality of laser beams are sequentially scanned in the main scanning direction with a first laser beam having a small output arranged on the downstream side in the sub-scanning direction and a second laser beam having a large output arranged on the upstream side. The toner image is heated stepwise by scanning the region where the first laser beam of the preceding line is scanned again with the second laser beam of the succeeding line. is there.

Japanese Patent No. 3016685 (Example, FIG. 1) JP 2008-89828 A (Best Mode for Carrying Out the Invention, FIG. 2)

  A technical problem to be solved by the present invention is to provide a fixing device that realizes a heat fixing process capable of fixing an image with a desired glossiness using a laser beam, and an image forming apparatus using the fixing device.

  According to the first aspect of the present invention, a first laser beam having a predetermined intensity can be heated and fixed on an unfixed image formed by a heat-fixable image forming material formed on a moving recording material. A first laser beam irradiation unit that irradiates for a long time and a second laser beam having a predetermined intensity are irradiated to the unfixed image for a longer time than the irradiation time of the first laser beam irradiation unit. A second laser beam irradiating unit, a determination unit that determines a gloss level required for an image of an unfixed image on the recording material, and at least a second laser based on the gloss level determined by the determination unit A fixing device comprising: control means for controlling the first laser light irradiation unit and the second laser light irradiation unit so as to change irradiation energy of the light irradiation unit.

According to a second aspect of the present invention, in the fixing device according to the first aspect, when the glossiness determined by the determination means is a low glossiness that is equal to or lower than a predetermined level, the control means When the laser beam irradiation operation is performed by the laser beam irradiation unit and the glossiness determined by the determination unit is higher than the low glossiness, the first laser beam irradiation unit and the second laser beam irradiation unit The fixing device is characterized in that the first laser light irradiation unit and the second laser light irradiation unit are controlled so as to perform the laser light irradiation operation by the laser light irradiation unit.
According to a third aspect of the present invention, in the fixing device according to the first or second aspect, the start position of the laser light irradiation region by the second laser light irradiation unit is a laser light irradiation region by the first laser light irradiation unit. The fixing device is located at least on the upstream side in the moving direction of the recording material compared to the starting position of the recording material.
According to a fourth aspect of the present invention, in the fixing device according to any one of the first to third aspects, the irradiation region of the laser beam by the first laser beam irradiation unit is irradiated with the second laser beam by the second laser beam irradiation unit. The fixing device is at least partially included in the region.
According to a fifth aspect of the present invention, in the fixing device according to any one of the first to fourth aspects, the determination unit can determine a high glossiness divided into a plurality of levels, and the control unit has a plurality of levels. In order to implement at least one or both of increasing the irradiation intensity of the laser beam by the second laser beam irradiation unit or extending the irradiation time of the laser beam as the gloss level is higher among the higher glossiness levels, The fixing device includes an adjustment unit that can variably adjust at least one or both of the irradiation intensity and the irradiation time of the laser beam from the second laser beam irradiation unit.
According to a sixth aspect of the present invention, in the fixing device according to any one of the first to fifth aspects, the determination unit can determine a low glossiness divided into a plurality of levels, and the control unit has a plurality of levels. Adjustment in which the irradiation intensity of the laser beam from the first laser beam irradiation unit can be variably adjusted so that the higher the glossiness is, the lower the glossiness is, the stronger the laser beam irradiation intensity is from the first laser beam irradiation unit. A fixing device having a section.
According to a seventh aspect of the present invention, in the fixing device according to any one of the first to sixth aspects, the determination unit can determine a high glossiness divided into a plurality of levels, and the control unit includes the determination unit When determining a gloss level belonging to a high level among a plurality of high gloss levels, a laser beam irradiation operation is performed by the first laser beam irradiation unit and the second laser beam irradiation unit. When determining the glossiness belonging to the low level among the high glossiness levels of the above, so as to perform the laser light irradiation operation by the second laser light irradiation unit without using the first laser light irradiation unit, A fixing device that controls the first laser light irradiation unit and the second laser light irradiation unit.

According to an eighth aspect of the present invention, in the fixing device according to any one of the first to seventh aspects, the determination unit includes an image information acquisition unit that acquires image information regarding an unfixed image on the recording material. In the fixing device, the glossiness required for the image of the unfixed image on the recording material is determined based on the image information acquired by the acquisition unit.
According to a ninth aspect of the present invention, in the fixing device according to the eighth aspect, the control unit has a higher gloss level than a predetermined level determined based on the image information acquired by the image information acquiring unit. For the image having the glossiness, the first laser light irradiation unit performs the laser light irradiation operation by the second laser light irradiation unit in addition to the laser light irradiation operation by the first laser light irradiation unit. A fixing device that controls a laser beam irradiation unit and the second laser beam irradiation unit.
According to a tenth aspect of the present invention, in the fixing device according to the ninth aspect, the control means has a higher gloss level obtained based on the image information acquired by the image information acquisition means than a predetermined level. For an image having a glossiness, at least one or both of increasing the laser beam irradiation intensity or increasing the laser beam irradiation time as the glossiness increases. The fixing device is characterized by carrying out the following.
According to an eleventh aspect of the present invention, in the fixing device according to the eighth aspect, the determination unit determines an image portion and a non-image portion based on the image information acquired by the image information acquisition unit, and And determining the glossiness obtained from the first laser irradiation unit and the image unit determined by the determination unit based on the glossiness determined by the determination unit. The second laser irradiation unit is controlled so that the non-image portion determined by the determination unit is irradiated with the laser beam by the first laser irradiation unit without using the second laser beam irradiation unit. And a fixing device that controls the first laser irradiation unit and the second laser irradiation unit.
According to a twelfth aspect of the present invention, in the fixing device according to the eleventh aspect, the control means determines in advance a glossiness required for the image portion determined based on the image information acquired by the image information acquisition means. For an image portion having a higher gloss level than the determined level, the higher the gloss level, the stronger the laser beam irradiation intensity by the second laser beam irradiation unit or the longer the laser beam irradiation time. The fixing device is characterized in that at least one or both of the above are performed.
According to a thirteenth aspect of the present invention, in the fixing device according to the eleventh or twelfth aspect, the control unit relates to the irradiation intensity of the laser beam by the first laser beam irradiation unit, and the irradiation intensity to the image portion and the non-image portion. The fixing device is characterized in that the first laser beam irradiation unit is controlled so as to be different from each other.
According to a fourteenth aspect of the present invention, in the fixing device according to the thirteenth aspect, the control device relates to the irradiation intensity of the laser beam by the first laser beam irradiation unit, and the irradiation intensity to the non-image part is larger than the image part. In the fixing device, the first laser beam irradiation unit is controlled to be weak.
According to a fifteenth aspect of the present invention, in the fixing device according to any one of the first to seventh aspects, the determination unit determines whether or not the recording material is of a type having a highly glossy surface portion. In the fixing device, the glossiness required for an image when the type has a glossy surface portion is determined as a glossiness higher than a predetermined level.
According to a sixteenth aspect of the present invention, there is provided a conveying means for conveying a recording material, an image forming means for forming an unfixed image by an image forming material capable of being heat-fixed on the recording material conveyed by the conveying means, and this image forming An image forming apparatus comprising: the fixing device according to claim 1 that heat-fixes the unfixed image formed by the means.

According to the first aspect of the present invention, it is possible to realize a heat fixing process capable of fixing an image with a desired glossiness using a laser beam.
According to the second aspect of the present invention, it is possible to realize a heat fixing process that can handle both an image that requires a high glossiness and an image that requires a low glossiness using a laser beam.
According to the third aspect of the present invention, even when high gloss is imparted to an image having a large amount of image forming material per unit area as compared with an aspect without this configuration, Roughness can be effectively prevented.
According to the fourth aspect of the present invention, the first laser beam and the second laser beam are used for an image that requires a high glossiness as compared with an aspect that does not have this configuration, and heat loss is small. A heat fixing process can be realized.
According to the invention which concerns on Claim 5, the glossiness of the image for which high glossiness is calculated | required can be changed.
According to the sixth aspect of the present invention, the glossiness of an image for which low glossiness is required can be changed.
According to the invention which concerns on Claim 7, compared with the aspect which does not have this structure, high glossiness is calculated | required only by devising the use combination of a 1st laser beam irradiation part and a 2nd laser beam irradiation part. The glossiness of the resulting image can be easily changed.
According to the eighth aspect of the invention, it is possible to determine the glossiness required for an image by grasping the image information of an unfixed image, as compared to an aspect without this configuration.
According to the ninth aspect of the present invention, the heat fixing process capable of fixing the image with a desired glossiness is realized by grasping the image information of the unfixed image, as compared with the aspect without this configuration. Can do.
According to the tenth aspect of the present invention, it is possible to easily change the glossiness of an image for which high glossiness is required by grasping the image information of the unfixed image, as compared with the aspect without this configuration. Can do.
According to the eleventh aspect of the present invention, as compared with the aspect without this configuration, the image portion and the non-image portion are discriminated by grasping the image information of the unfixed image, and the image portion has a desired glossiness. It is possible to realize a heat fixing process capable of fixing at a high degree, and to effectively avoid an unfixed state of an isolated image forming material in a non-image portion.
According to the twelfth aspect of the present invention, as compared with an aspect not having this configuration, it is possible to discriminate between an image portion and a non-image portion by grasping image information of an unfixed image, and high glossiness is required. A heat fixing process capable of fixing the image portion with a plurality of levels of glossiness can be realized, and an unfixed state of the isolated image forming material in the non-image portion can be effectively avoided.
According to the thirteenth aspect of the present invention, as compared with the aspect without this configuration, the unfixed state of the image forming material connected to the planar shape of the image portion and the isolated image forming material of the non-image portion is effectively avoided. be able to.
According to the fourteenth aspect of the present invention, the non-fixed state of the isolated image forming material in the non-image portion can be effectively avoided with less irradiation energy than in the aspect without this configuration.
According to the fifteenth aspect of the present invention, the glossiness required for the image is matched to the recording material by grasping the type of the recording material on which the unfixed image is formed, as compared with the aspect without this configuration. Can be determined.
According to the sixteenth aspect of the present invention, it is possible to easily construct an image forming apparatus including a fixing device capable of realizing a heat fixing process capable of fixing an image with a desired glossiness using a laser beam.

(A) is explanatory drawing which shows the outline | summary of embodiment of the fixing device with which this invention is applied, (b) is explanatory drawing which shows the outline | summary of embodiment of the image forming apparatus incorporating the fixing device of (a). is there. (A) is an explanatory view showing a heat fixing process for an image for which low glossiness is required by the fixing device shown in FIG. 1 (a), and (b) is a high glossiness required by the fixing device shown in FIG. 1 (a). It is explanatory drawing which shows the heat fixing process about an image. 1 is an explanatory diagram showing an overall configuration of Embodiment 1 of an image forming apparatus to which the present invention is applied. FIG. 2 is an explanatory diagram illustrating a fixing device used in Embodiment 1. (A) is explanatory drawing which shows the principal part of the fixing device which concerns on Embodiment 1, (b) is a 1st laser beam, the irradiation time of a 2nd laser beam, and the irradiation intensity seen from the toner typically It is explanatory drawing shown. (A) is the arrow view which looked at the 1st laser beam irradiation part from VI direction of FIG. 4, (b) is the arrow view which looked at the 2nd laser beam irradiation part from VI direction of FIG. It is explanatory drawing which shows the irradiation energy in the width direction of the recording material by a 1st light irradiation part and a 2nd light irradiation part. 4 is an explanatory diagram schematically showing a control system of the image forming apparatus used in Embodiment 1. FIG. It is a flowchart which shows the heat fixing control process of the fixing device by the control apparatus of FIG. (A) is explanatory drawing which shows the gloss mode with respect to the image type on coated paper and each image type, (b) is explanatory drawing which shows the gloss mode with respect to the image type on plain paper and each image type. (A) is an explanatory view schematically showing heat fixing processing in a low gloss mode for plain paper, (b) is an explanatory view schematically showing heat fixing processing in a high gloss mode for coated paper, and (c) is a coated paper. It is explanatory drawing which shows typically the heat fixing process of the low gloss mode with respect to this. FIG. 6 is an explanatory diagram illustrating a main part of a fixing device according to a second embodiment. It is explanatory drawing which shows the irradiation conditions of the 1st laser beam irradiation part used in Embodiment 2, and the 2nd laser beam irradiation part. (A) is explanatory drawing which shows the deformation | transformation form of the 2nd laser beam irradiation part of the fixing device based on Embodiment 2, (b) is the description which shows the operation | movement process of the 2nd laser beam irradiation part shown to (a). FIG. FIG. 10 is an explanatory diagram illustrating a main part of a fixing device according to a third embodiment. (A)-(c) is explanatory drawing which shows typically the heat fixing process of the fixing device of Embodiment 3. FIG. (A) is explanatory drawing which shows the principal part of the fixing device based on Embodiment 4, (b) (c) is explanatory drawing which shows the deformation | transformation form of the fixing device based on Embodiment 4. FIG. (A) is an explanatory view showing a main part of a fixing device according to Embodiment 5, and (b) is an explanatory view showing an example of an unfixed image on a recording material to be fixed. 10 is a flowchart showing a heat fixing control process by a control device in the fixing device according to the fifth embodiment. (A) is an explanatory view schematically showing a heat fixing process for an image area of an unfixed image on a recording material, and (b) is a heat fixing process for a non-image area of an unfixed image on a recording material. It is explanatory drawing shown typically. It is explanatory drawing which shows the relationship between the irradiation time of the laser beam by a 1st laser beam irradiation part, and irradiation energy regarding the fixing possible condition with respect to the surface image of an image part, and the isolated toner of a non-image part. (A) is explanatory drawing which shows typically the heat transfer state of the laser beam by the 1st laser beam irradiation part with respect to an isolated toner, (b) is the heat transfer state of the laser beam by the 1st laser beam irradiation part with respect to a surface image. It is explanatory drawing which shows this typically. FIG. 22 is an explanatory diagram showing an example in which the irradiation energy for isolated toner is larger than that of a surface image under the fixable condition shown in FIG. 21. FIG. 22 is an explanatory diagram showing an example in which the irradiation energy with respect to the isolated toner is smaller than that of the surface image under the fixable condition shown in FIG. 21. FIG. 7 is an explanatory diagram illustrating measurement results of changes in glossiness associated with recording material types and irradiation methods using the fixing device according to Example 1;

Outline of Embodiment As shown in FIG. 1B, the image forming apparatus according to the present embodiment includes a conveying unit 6 that conveys a recording material 5, and a recording material 5 that is conveyed by the conveying unit 6. The image forming means 7 for forming an unfixed image TG using an image forming material capable of being heat-fixed to the image forming apparatus 7 and a fixing device 8 for heating and fixing the unfixed image TG formed by the image forming means 7 are provided. .
Here, the recording material 5 is not limited to a continuous recording material that is continuous in the transport direction, and includes a recording material that has been cut at a predetermined size. A material having a smooth coat layer applied to the surface of the material or plain paper as a base material made of paper fibers may be appropriately selected.
In addition, the image forming means 7 includes a wide range of materials that produce an image on the recording material 5 using an image forming material (for example, toner) that can be heat-fixed. You can choose.
Further, in the present embodiment, as shown in FIG. 1A, the fixing device 8 determines in advance an unfixed image TG made of a heat-fixable image forming material formed on the moving recording material 5. A first laser beam irradiation unit 1 that irradiates a _first laser beam having a predetermined intensity for a predetermined heating and fixing time t _{1; and} a second laser beam having a predetermined intensity for the unfixed image TG. The second laser beam irradiation unit 2 that irradiates the laser beam of time t ₂ longer than the irradiation time t ₁ of the first laser beam irradiation unit 1 and the unfixed image TG on the recording material 5. The determination means 3 for determining the required glossiness and the first laser light irradiation so as to change the irradiation energy of at least the second laser light irradiation section 2 based on the glossiness determined by the determination means 3 Control means 4 for controlling the unit 1 and the second laser beam irradiation unit 2 , It is those with a.

In such technical means, the first laser light irradiation unit 1 and the second laser light irradiation unit 2 include a predetermined number of laser light sources 1a and 2a, and separate or integrated with the laser light sources 1a and 2a. And a condensing unit (for example, a condensing lens, etc.) 1b and 2b that condenses the laser light emitted from the laser light sources 1a and 2a in an irradiation region. These laser light irradiation units 1 and 2 may include other functional elements, and for example, a reflection member for reusing the light reflected by the irradiation region on the recording material 5 as a heat source is added. There are aspects.
Further, the intensity of the first laser beam by the first laser beam irradiation unit 1 needs to be at least an intensity capable of performing the heat fixing process in a predetermined heat fixing time.
Further, the second laser light irradiation unit 2 only needs to set the irradiation time t2 of the _second laser light longer than the irradiation time t1 of the _first laser light, and the intensity of the second laser light. May be set stronger than that of the first laser beam, or may be set equal or weaker.
However, even if the intensity of the first laser light is smaller than the intensity of the second laser light, the intensity of the first laser light having a short irradiation time is long in the irradiation region on the recording material 5. It can happen that it becomes larger than the laser beam.
Furthermore, the arrangement of the first laser light irradiation unit 1 and the second laser light irradiation unit 2 may be appropriately selected, and the arrangement of the first laser light irradiation region and the second laser light irradiation region is acceptable. The relationship may be arranged before and after a gap, but from the viewpoint of reducing the waste of heat fixing energy, the gaps are arranged adjacent to each other without gaps, or arranged so as to partially overlap. This embodiment is preferable.

The determination means 3 may be any means that determines the glossiness required for the image of the unfixed image TG, and may determine that the gloss is selected so as to be instructed according to the user's request. However, from the viewpoint of determining the glossiness suitable for each image, the glossiness is determined for each image area based on the image information of the unfixed image TG, or according to the type of the recording material 5. For example, it is preferable to determine that a high gloss level A is required in principle for a type having a highly glossy surface portion such as so-called coated paper.
Furthermore, as the control unit 4, the first laser beam irradiation unit 1 and the second laser beam irradiation unit 2 may be controlled according to the glossiness required for the image determined by the determination unit 3. In this control method, it is necessary to change at least the irradiation energy of the second laser light irradiation unit 2. Here, “changing the irradiation energy of the second laser light irradiation unit 2” is not limited to a mode in which the laser light having a predetermined irradiation intensity is turned on and off, and the irradiation intensity of the laser light is changed. Or a mode in which the irradiation time of the laser light is changed.

Next, typical aspects and preferred aspects of each component used in the present embodiment will be described.
First, as a typical aspect of the control means 4, when the glossiness determined by the determination means 3 is a low glossiness B equal to or lower than a predetermined level, the laser beam emitted from the first laser beam irradiation unit 1 is used. When the glossiness determined by the determination means 3 is higher than the low glossiness B, the first laser beam irradiation unit 1 and the second laser beam irradiation are performed. The aspect which controls the 1st laser beam irradiation part 1 and the 2nd laser beam irradiation part 2 so that the irradiation operation of the laser beam by the part 2 may be mentioned.
In this case, the control means 4 uses the first and second laser light irradiation units 1 to be used depending on whether the glossiness determined by the determination means 3 is high glossiness A or low glossiness B. , 2 may be used, and when low glossiness B is sufficient (printing on plain paper with a rough surface, monochrome monochrome image printing, highlight image printing with many isolated images, etc.) The laser beam irradiation operation by the first laser beam irradiation unit (short-time irradiation) 1 is performed. As shown in FIG. 2A, the laser beam irradiation operation by the first laser beam irradiation unit 1 (short-time irradiation). However, even if the minimum heat energy required for the heat fixing process is sufficient, the unfixed image TG is fixed by heating, and the surface portion becomes a rough surface mb that is not smooth. Obtained as a glossy fixed image TG (B).
On the other hand, when a high gloss level A is required (printing on a so-called coated paper having a high gloss on the surface, color image printing, etc.), as shown in FIG. The laser beam irradiation operation (short-time irradiation + long-time irradiation) by the second laser beam irradiation unit 2 is performed, and the image portion of the unfixed image TG is slowly melted over time to smooth the surface of the image portion. The surface ma may be used to obtain a highly glossy fixed image TG (A).
Moreover, as a preferable arrangement example of the first laser beam irradiation unit 1 and the second laser beam irradiation unit 2, the start position of the laser beam irradiation region by the second laser beam irradiation unit 2 is the first laser beam. Examples include those positioned at least upstream in the moving direction of the recording material 5 relative to the start position of the irradiation region of the laser beam by the irradiation unit 1. In this example, when both the first laser beam irradiation unit 1 and the second laser beam irradiation unit 2 are used, the irradiation with the second laser beam is started before the irradiation with the first laser beam. The In this case, if the amount of the image forming material per unit area is large and the first laser beam having a high intensity is irradiated for a short time, the surface of the image tends to be rough due to overheating. Such a tendency is not seen in the embodiment as in this example. If the amount of the image forming material per unit area is reduced using a small diameter image forming material, the first laser beam having a high intensity is irradiated for a short time before the second laser beam. However, the surface roughness of the image due to overheating as described above is not observed.
Further, when both the first and second laser beam irradiation units 1 and 2 are used, from the viewpoint of effectively suppressing heat loss, the laser beam irradiation region by the first laser beam irradiation unit 1 is used. Is preferably included in at least a part of the second laser light irradiation region by the second laser light irradiation unit 2.

The glossiness may be uniquely set in advance, but the glossiness may be adjusted as necessary.
For example, as a typical mode for adjusting the glossiness of a high gloss image, the determination means 3 can determine a high glossiness A divided into a plurality of levels, and the control means 4 can determine a high glossiness A of a plurality of levels. The higher the glossiness level, the higher the laser beam irradiation intensity by the second laser beam irradiation unit 2 or the longer the laser beam irradiation time, or both are implemented. Examples include an adjustment unit that can variably adjust at least one or both of the irradiation intensity and / or irradiation time of the laser beam by the laser beam irradiation unit 2. In this aspect, by adjusting at least one or both of the irradiation intensity and the irradiation time of the second laser light, the thermal energy applied to an image for which a high gloss level A is required is increased or decreased. As a result, the glossiness of the image increases or decreases. Here, examples of the adjustment unit that can variably adjust the irradiation time include an optical system that variably adjusts the irradiation range of the laser light, and an aspect that adjusts whether or not another laser light source is additionally used.
Furthermore, as another typical mode for adjusting the glossiness of a high gloss image, the determination unit 3 can determine a high gloss level A divided into a plurality of levels, and the control unit 4 includes a plurality of determination units 3. When the glossiness belonging to a high level is determined among the high glossiness A, the laser beam irradiation operation is performed by the first laser beam irradiation unit 1 and the second laser beam irradiation unit 2, and the determination unit 3 When determining the glossiness belonging to the lower level among the plurality of high glossiness levels A, the laser beam irradiation operation by the second laser beam irradiation unit 2 is performed without using the first laser beam irradiation unit 1. In addition, one that controls the first laser light irradiation unit 1 and the second laser light irradiation unit 2 can be mentioned. In this aspect, as the glossiness of the high gloss image, the thermal energy is sufficiently secured by using the first laser beam irradiation unit 1 and the second laser beam irradiation unit 2 at a high gloss level, and the glossiness is low. In the standard, the thermal energy is somewhat suppressed by using only the second laser beam irradiation unit 2 without using the first laser beam irradiation unit 1.
Further, as a typical mode for adjusting the glossiness of a low gloss image, the determination means 3 can determine a low glossiness B divided into a plurality of levels, and the control means 4 has a plurality of low glossiness levels. An adjustment unit capable of variably adjusting the irradiation intensity of the laser beam from the first laser beam irradiation unit 1 so that the higher the glossiness level of B is, the stronger the irradiation intensity of the laser beam from the first laser beam irradiation unit 1 is. The thing which has is mentioned. In this aspect, by adjusting the irradiation intensity of the first laser beam variably, the thermal energy applied to an image for which a low glossiness B is required increases or decreases, and accordingly, the glossiness of the image increases or decreases. To do. Here, since the irradiation time of the first laser light is originally short, the parameter for variably adjusting the first laser light is intended only for the irradiation intensity.

Further, as a typical aspect of the determination unit 3, there is an image information acquisition unit (not shown) that acquires image information related to the unfixed image TG on the recording material 5, and an image acquired by the image information acquisition unit. Examples include determining the glossiness required for the image of the unfixed image TG on the recording material 5 based on the information.
This is to determine the glossiness required for the image by paying attention to the image information of the unfixed image TG. For example, it is determined whether the image requires a high glossiness A or a low glossiness B, The glossiness required for the image is determined.
As a typical mode of the control unit 4 when using the determination unit 3 of such a mode, the glossiness obtained based on the image information acquired by the image information acquisition unit is higher than a predetermined level. For an image having a gloss level A, in addition to the laser beam irradiation operation by the first laser beam irradiation unit 1, the laser beam irradiation operation by the second laser beam irradiation unit 2 is performed. The laser beam irradiation unit 1 and the second laser beam irradiation unit 2 may be controlled.
In this case, as a preferable mode of the control means 4, for an image whose glossiness A obtained based on the image information acquired by the image information acquisition means is higher than a predetermined level, The aspect which implements at least any one or both of making the irradiation intensity | strength of the laser beam by the 2nd laser beam irradiation part 2 strong, or lengthening the irradiation time of a laser beam, so that glossiness is high is mentioned.
Furthermore, as a preferable aspect of this kind of determination means 3 and control means 4, the determination means 3 discriminates between an image part and a non-image part based on the image information acquired by the image information acquisition means, The controller 4 determines the glossiness obtained from the first laser irradiation based on the glossiness determined by the determining means 3 for the image portion determined by the determining means 3. The first laser irradiation unit 1 does not use the second laser light irradiation unit 2 for the non-image part determined by the determination unit 3 by controlling the unit 1 and the second laser irradiation unit 2. A device that controls the first laser irradiation unit 1 and the second laser irradiation unit 2 so as to perform the light irradiation operation is exemplified.
In this aspect, the image portion and the non-image portion are discriminated based on the image information of the unfixed image TG, the glossiness required for the image portion is determined, and the image portion is irradiated with laser light based on the glossiness Take control. On the other hand, with respect to the non-image portion, although there is essentially no image portion, there is a concern that a partially floating image forming material or the like adheres as an isolated image forming material. If this isolated image forming material is left unfixed, there is a possibility that the recording material may become dirty or the image may be disturbed. Therefore, it is preferable to fix this isolated image forming material. At this time, even if this isolated image forming material is irradiated with laser light at a low energy for a long time, it is not very effective. A method of irradiating with energy for a short time is adopted.
In this aspect, as a preferable aspect for the image portion of the control means 4, the required glossiness among the image portions determined based on the image information acquired by the image information acquisition means is higher than a predetermined level. For the image portion having the gloss level A, the higher the gloss level, the stronger the laser beam irradiation intensity by the second laser beam irradiation unit 2 or the longer the laser beam irradiation time or both. The mode which implements is mentioned.

Furthermore, as a preferable aspect for the non-image portion of the control means 4, the first laser light is applied so that the irradiation intensity of the image portion and the non-image portion is different with respect to the irradiation intensity of the laser light by the first laser light irradiation portion 1. The aspect which controls the irradiation part 1 is mentioned.
In this aspect, when the image part and the non-image part are irradiated with the laser light from the first laser light irradiation part 1, the irradiation energy condition for fixing the isolated image forming material of the non-image part, and the image part Usually, the irradiation energy condition for fixing the image forming material connected to the surface image is often different. At this time, it is preferable to select different irradiation intensities for the image portion and the non-image portion in accordance with each irradiation energy condition.
Here, as a more preferable aspect of the control device 4, as for the irradiation intensity of the laser beam by the first laser beam irradiation unit 1, the first laser beam is set so that the irradiation intensity for the non-image part is weaker than that of the image part. The aspect which controls the irradiation part 1 is mentioned.
When fixing an isolated image forming material in the non-image area, a method of setting the irradiation intensity strongly is adopted because the area exposed to the outside air is larger than in the case of an image forming material connected to the surface shape of the image area. There are many cases. However, when a short-time irradiation method with a shorter irradiation time is adopted, the irradiation energy for fixing the isolated image forming material can be made smaller than the image forming material connected to the surface, and the irradiation intensity can be reduced accordingly. It can be set weakly. This is because, when the irradiation energy is small, the amount of heat received by the isolated image forming material exceeds the amount of heat transmitted to the periphery, so that the image forming material reaches a low viscosity state at a high temperature and can be fixed. On the other hand, in the case of an image forming material connected in a planar shape, the weight of the image forming material per unit area, that is, the heat capacity, is large, so that a situation occurs in which fixing cannot be performed with irradiation energy that can be fixed with an isolated image forming material.
Further, as another representative aspect of the determination means 3, it is determined whether or not the recording material 5 is of a type having a high gloss surface portion, and the recording material 5 is of a type having a high gloss surface portion. In another aspect, the glossiness required for an image is determined as a glossiness A higher than a predetermined level.
This focuses on the type of the recording material 5 on which the unfixed image TG is formed and determines the glossiness required for the unfixed image TG. However, the present invention is not limited to this. Of course, it is possible to use a mode in which a method for determining glossiness according to type and a method for determining glossiness based on the above-described image information are appropriately combined.

Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings.
Embodiment 1
-Overall configuration-
FIG. 3 shows the overall configuration of the first embodiment of the image forming apparatus to which the present invention is applied.
In FIG. 1, an image forming apparatus 20 includes a conveying apparatus 30 that conveys a recording material 10 and an image forming apparatus that forms an unfixed image composed of a color image or a black image on the recording material 10 conveyed by the conveying apparatus 30. 21 and a fixing device 40 that heat-fixes an unfixed image formed by the image forming device 21.
In the present embodiment, the recording material 10 is a continuous recording paper wound around a core material or a continuous recording paper folded into a predetermined size.
-Conveying device-
Here, the conveyance device 30 is provided with a recording material supply device 31 that can be sequentially supplied with the recording material 10 loaded thereon, and the recording material supply device 31 is provided on the opposite side of the image forming device 21 and the fixing device 40. In addition, the recording material take-up device 32 that takes up the image-formed recording material 10 and the recording material 10 supplied from the recording material supply device 31 pass through the image forming device 21 and the fixing device 40 to the recording material take-up device 32. An appropriate number of transport members provided at appropriate intervals in the transport path are provided so as to be transportable along a predetermined transport path.
In this example, as the conveying member, an appropriate number of conveying rolls 33 to 37 are used in the conveying path, and the conveying roll 37 immediately before the recording material winding device 32 is used for conveying continuous recording paper as the recording material 10. The position of the recording material winding device 32 is adjusted so that the recording material winding device 32 is wound without tearing the continuous recording paper so that the continuous recording paper is not torn. ing.
Further, in this example, a conveyance belt 38 that conveys the recording material 10 along a predetermined linear locus is disposed at a portion facing the fixing device 40.

-Imaging device-
In the present embodiment, the image forming device 21 creates toner images of a plurality of color components (in this example, yellow (Y), magenta (M), cyan (C), and black (K)), and records them respectively. A plurality of image forming units 22 (specifically, 22Y, 22M, 22C, and 22K) to be transferred to the material 10 are provided. In this example, the black image forming unit 22K is disposed at the final stage, but the arrangement order of the image forming units 22 is not limited to the illustrated order, and may be appropriately selected.
In this example, the basic configuration of each image forming unit 22 employs an electrophotographic method. For example, a drum-shaped photoconductor having a photosensitive layer formed on the surface and capable of rotating in a predetermined direction. Around the photoconductor 23, and a charging device 24 such as a corotron for charging the photoconductor 23 in advance, and an electrostatic latent image with light on the photoconductor 23 charged by the charging device 24. A latent image writing device 25 such as a laser scanning device for writing an image, a developing device 26 for developing the electrostatic latent image written by the latent image writing device 25 with each color component toner, and the developing device 26 For example, a transfer device 27 such as a transfer roll to which a transfer bias is applied and a cleaning device 28 for cleaning residual toner on the photosensitive member 23 are sequentially arranged to transfer the developed toner image to the recording material 10. is there.
At this time, each image forming unit 22 sequentially forms unfixed toner images (unfixed images) on the recording material 10, and these unfixed images are transferred to the fixing device 40 located at the subsequent stage of the conveyance path. Moving.

-Fixing device-
In the present embodiment, as shown in FIGS. 4 and 5A, for example, the fixing device 40 includes a first laser light irradiation unit 41 that irradiates the _first laser light L1, and a second laser light. And a _second laser beam irradiation unit 42 for irradiating L2. The conveyor belt 38 is stretched between a pair of tension rolls 39a and 39b, for example.
Here, the first laser light irradiation unit 41 includes a laser light source 41 a having a predetermined irradiation intensity, and a condenser lens 41 b that focuses the laser light from the laser light source 41 a toward the recording material 10. Yes. Then, as shown in FIG. 6A, the laser light sources 41a are arranged in a line at a predetermined interval p along the width direction Y that intersects the conveyance direction X of the recording material 10 (see FIG. 4). Consists of a plurality of laser elements, and a condensing lens 41b is provided corresponding to each laser element.
In this example, the laser light source 41a emits a laser beam having a predetermined irradiation intensity with a predetermined irradiation width, and the condenser lens 41b is formed as shown in FIGS. With respect to the conveyance direction X (see FIG. 4) of the recording material 10, the irradiation region is narrowed down, specifically, with a short irradiation time t ₁ (for example, 0.5 to several ms) for the toner image on the recording material 10. The first laser light L ₁ is focused so that the irradiation intensity viewed from the toner image is W ₁ in the irradiation region R ₁ to be irradiated. That is, as shown in FIG. 5A, if the focal length of the condenser lens 41b of this example is f and the distance between the center plane position of the condenser lens 41b and the surface of the recording material 10 is h, the focal length f. A condensing lens 41b made of, for example, a convex lens that is slightly larger than h may be selected and arranged so as to ensure the irradiation region R ₁ (irradiation time t ₁ , irradiation intensity W ₁ ).
On the other hand, as shown in FIG. 6A, the condensing lens 41b overlaps the laser light from the laser light source 41a with that of the adjacent laser light source 41a in the width direction Y of the recording material 10. As shown in FIG. 7, a substantially uniform irradiation intensity W ₁ is secured in the width direction Y of the recording material 10.
In this example, the requirements (irradiation time t ₁ , irradiation intensity W ₁ ) of the irradiation region R ₁ of the first laser beam L ₁ are that the unfixed image TG on the recording material 10 is at least heat-fixed. It is selected to satisfy.

The second laser light irradiation unit 42 is disposed on the upstream side in the conveyance direction X of the recording material 10 with respect to the first laser light irradiation unit 41, and a laser light source 42a having a predetermined irradiation intensity; A condensing lens 42b that diffuses the laser light from the laser light source 42a toward the recording material 10 is provided. Similarly to the first laser light irradiation unit 41, the laser light sources 42a are arranged in a line at a predetermined interval p along the width direction Y of the recording material 10, as shown in FIG. 6B. The condensing lens 42b is provided corresponding to each laser element.
In this example, the laser light source 42a emits laser light having a predetermined irradiation intensity that is stronger than the irradiation intensity of the laser light source 41a of the first laser light irradiation unit 41, for example, with a predetermined irradiation width. The condensing lens 42b is sufficiently larger than the irradiation region R1 of the _first laser light irradiation unit 41 in the conveyance direction X of the recording material 10, as shown in FIGS. widely diffused irradiation region was, in particular irradiation intensity viewed from the toner image to the irradiation region R ₂ which is irradiated by a long irradiation time t ₂ with respect to the toner image _(e.g. 10 to number 10 ms) on the recording material 10 is W _{2 (in} this example W _{2 <W 1)} is obtained so as to diffuse the made such second laser beam L _2. That is, as shown in FIG. 5 (a), the focal length of the condensing lens 42b of this embodiment f _1, if the distance between the focal position and the recording material 10 surface of the condenser lens 42b and f _2, a focal length A condenser lens 42b made of a convex lens having a short focal length, for example, satisfying the relationship of f ₁ <f ₂ is selected and arranged so as to ensure the irradiation region R ₂ (irradiation time t ₂ , irradiation intensity W ₂ ). That's fine.
On the other hand, the condensing lens 42b is adjacent to the laser light from the laser light source 42a in the width direction Y of the recording material 10, as shown in FIG. is diffused to the extent that overlap each other and that of the laser light source 42a that, as shown in FIG. 7, so as to ensure a substantially uniform illumination intensity W ₂ with respect to the width direction Y of the recording medium 10.
Further, in the present embodiment, the non-illuminated region R ₀ between the irradiation region R ₂ of the irradiation region R ₁ and the second laser beam irradiation section 42 of the first laser beam irradiation unit 41 is present, heating From the viewpoint of suppressing heat loss due to the fixing process, it is preferable that the non-irradiation region R ₀ is as small as possible, and an embodiment in which the non-irradiation region R ₀ does not exist is preferable.
In this example, a convex lens is used as the condenser lens 42b. However, the present invention is not limited to this, and a concave lens or a combination of a concave lens and a convex lens may be used.

-Control system-
Next, a control system of the image forming apparatus used in this embodiment will be described with reference to FIG.
In the figure, reference numeral 50 denotes a control device for controlling the image forming device 21 and the fixing device 40, and reference numeral 61 denotes an image data input device for inputting image data to be imaged by the image forming device 21 to the control device 50. For example, a client machine connected to the image forming apparatus according to the present embodiment over a network, an image reading apparatus that reads image data recorded in various recording media, and the like can be given. Further, reference numeral 62 denotes a coated paper in which the recording material 10 has a coating layer such as a smooth coating layer on the surface, or no coating layer such as a coating layer on the surface and paper fibers are exposed on the surface. This is a recording material selection switch that selects plain paper as it is.
Then, based on the input signals from the image data input device 61 and the recording material selection switch 62, the control device 50 executes a control program related to the image forming control process and a control program related to the heat fixing process (see FIG. 10). A predetermined control signal is sent to the image device 21 and the fixing device 40. Reference numeral TG denotes an unfixed image formed on the recording material 10.

-Operation example of image forming apparatus-
Next, an operation example of the image forming apparatus according to the present embodiment will be described.
When an image forming mode of a color image (here, a full color image) or a black image is selected by an image forming mode selection switch (not shown), the control device 50 selects a color image forming mode. When all the image forming units 22 (22Y to 22K) of the image forming apparatus 21 are operated for image forming and the image forming control process is executed. On the other hand, when the image forming mode for the black image is selected, the image forming is performed. Only the black image forming unit 22 (22K) in the apparatus 21 may be operated for image formation to perform image formation control processing.
Further, the control device 50 executes the heat fixing control process according to the flowchart of FIG.
Specifically, the control device 50 determines whether or not the recording material 10 is coated paper based on an input signal from the recording material selection switch 62, and when the recording material 10 is coated paper, the high gloss mode is set. On the other hand, when the recording material 10 is plain paper, the low gloss mode is selected if conditions for not determining the image type (image type) are set in advance.
Here, when the high gloss mode is selected, the control device 50 performs the heat fixing process using both the first laser light irradiation unit 41 and the second laser light irradiation unit 42, When the gloss mode is selected, the heat fixing process is performed using the first laser beam irradiation unit 41.
Further, in the present embodiment, a method is employed in which the image type is not determined when the recording material 10 is plain paper, and the image type is determined when the image type recording material 10 is coated paper. .
That is, the control device 50 selects the high gloss mode in principle when the recording material 10 is coated paper, but further forms on the recording material 10 based on the image data input from the image data input device 61. The image type to be determined is determined, and whether or not there is a color image area is determined. If the color image area does not exist, the low gloss mode is selected. If the color image area exists, the image type is determined in advance. It is determined whether or not there is a highlight image (including an isolated image) or a black image area having a low image density, and a color image area TG (A) and a highlight image area TG (B) (or a black image) When the region (TG (C))) exists, as shown in FIG. 10A, the highlight image region TG (B) (or the black image region (TG (C)) is the low gloss mode LG, Color image area TG A) is determined to be the high gloss mode HG, and when the highlight image area TG (B) (or the black image area (TG (C)) does not exist, only the color image area TG (A) exists. As a result, the high gloss mode is determined for all areas.
As shown in FIG. 10B, when the recording material 10 is plain paper, the low gloss mode LG is selected no matter what kind of image type exists on the recording material 10.

Thus, when the heat fixing control process by the control device 50 is performed, the heat fixing process by the fixing device 40 as shown in FIG. 11 is performed.
First, as shown in FIG. 11A, when the recording material 10 is plain paper, the low gloss mode (first laser) is used regardless of the image type of the unfixed image TG on the recording material 10. Only the light irradiation unit 41 is used). For this reason, the fixed image that has been heat-fixed is held with low gloss, so that, for example, a black character image without glare is output as an easy-to-see image.
Further, as shown in FIG. 11B, the recording material 10 is coated paper, and the color image region TG (A) of the unfixed image is in the high gloss mode (the first laser light irradiation unit 41 and the first laser beam irradiation unit 41). 2 is used). For this reason, since the color image on the coated paper becomes highly glossy, a highly glossy color image that does not lose the gloss of the coated paper can be obtained.
In particular, in the present embodiment, the unfixed image TG on the recording material 10 is first irradiated with the second laser light from the second laser light irradiation unit 42 for a long time before the first laser light. Since the first laser beam from the irradiation unit 41 is irradiated for a short time, no matter whether a toner having a large diameter or a small diameter is used as the toner constituting the unfixed image TG, the toner is not fixed due to overheating. There is no concern that the surface of the image TG becomes rough.
Further, as shown in FIG. 11C, even if the recording material 10 is coated paper, the highlight image region TG (B) or the black image region TG (C) of the unfixed image is low gloss mode ( Only the first laser light irradiation unit 41 is used). For this reason, even in the color image region TG (A), the highlight image region TG (B) and the black image region TG (C) should not have high gloss and should be easy to see the image. Is obtained.
In this embodiment, the gloss mode determination method for the image type is not limited to the method shown in this embodiment, and even if a highlight image or a black image exists on the coated paper. The high gloss mode may be selected, or the high gloss mode may be selected as appropriate when a color image exists on plain paper.

Embodiment 2
FIG. 12 is an explanatory diagram showing an outline of the fixing device according to the second embodiment.
In the figure, the basic configuration of the fixing device 40 is substantially the same as that of the first embodiment, but the control method of the control device 50 is different from that of the first embodiment. Components similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted here. The same applies to the following embodiments.
In the present embodiment, the control device 50 has the high gloss mode HG divided into a plurality of grades (G ₁ , G ₂ , G ₃ , G _{4 in} this example). The irradiation intensity W ₁ from the laser light source 41 a of the laser light irradiation unit 41 is kept at a certain level (for example, grade D ₁ ), and the irradiation intensity W ₂ of the laser light source 42 a of the second laser light irradiation unit 42 is variably set. It is what I did.
Further, in the present embodiment, in the control device 50, the low gloss mode LG is divided into a plurality of grades (D ₁ and D _{2 in} this example), and based on these grades, the first laser light irradiation unit the irradiation intensity W ₁ from the laser light source 41a of 41 is obtained so as to variably set.
Here, regarding the laser light sources 41a and 42a (hereinafter referred to as the first laser light source 41a and the second laser light source 42a as necessary) of the first laser light irradiation unit 41 and the second laser light irradiation unit 42, When the relationship between irradiation energy and irradiation time was examined, the result shown in FIG. 13 was obtained. In addition, the vertical axis | shaft of FIG. 13 points out the irradiation energy based on the product of the irradiation intensity | strength of each laser light source 41a, 42a, and irradiation time, and the irradiation time of a horizontal axis is described with the logarithmic scale.
According to the figure, for example, regarding the irradiation condition of the first laser light source 41a, the minimum irradiation energy necessary for heating and fixing a black image is Lb, and the minimum irradiation energy necessary for heating and fixing a color image. Lc (Lc> Lb). Further, with respect to irradiation energy and irradiation time, a highlight image (here, in the region on the left side of the boundary line U that increases in a curved line in the region on the shorter irradiation time side, is here. Then, it was confirmed that fixing of a black character image with a printing rate of 5% is possible.
In addition, for the second laser light source 42a, it is understood that in the region where the irradiation time is long, the glossiness of high gloss (high gloss) changes as the irradiation energy increases and decreases at the same irradiation time. It was confirmed that the glossiness increased in order from G _{1 to} G _{4 as} it increased.
In the present embodiment, the high gloss mode is divided into a plurality of grades G _{1 to} G ₄ based on such characteristics, and the gloss level can be finely adjusted according to the type and image type of the recording material 10. .
In the present embodiment, for example, the low-gloss mode can also be switched by, for example, grades D ₁ and D ₂ that change the irradiation energy necessary for fixing between black images or color images as image types. It is.

◎ Deformation form 2-1
Figure 14 (a) (b) are those second irradiation energy by the laser light source 42a of the laser beam irradiation section 42 as a method for the variable, to change the irradiation time t ₂ by the laser light source 42a.
This holder 43 in the second condenser lens 42b of the laser beam irradiation unit 42 to lift the support at the lifting device 44, the condenser lens 42b is moved up and down, the reference position irradiation time t ₂ by the laser light source 42a and (FIG. 14 (a) position for obtaining the irradiation time t ₂ of the present embodiment) shorter irradiation time t ₂ that close to the recording material 10 than _', conversely, than the reference position be moved away from the recording material 10 And a long irradiation time t ₂ ″.
As a method for changing the irradiation energy by the laser light source 42a of the second laser light irradiation unit 42, both the irradiation intensity W ₂ and the irradiation time t ₂ by the laser light source 42a may be changed. Of course.

Embodiment 3
FIG. 15 is an explanatory diagram showing an outline of the fixing device according to the third embodiment.
In the figure, the basic configuration of the fixing device 40 is substantially the same as that of the first embodiment, but the control method of the control device 50 is different from that of the first embodiment.
In the present embodiment, the control device 50 divides the high gloss mode HG into a plurality of grades (G ₁ and G _{2 in} this example), and based on these grades, the first laser light irradiation unit 41 has maintaining the irradiation intensity W ₁ from the laser source 41a at a constant level, and, while maintaining the irradiation intensity W ₂ of the second laser light source 42a of the laser beam irradiation unit 42 at a constant level, varying the irradiation energy of the high gloss mode HG It is something that is set.
In the present embodiment, when the low gloss mode LG is selected, as shown in FIG. 16A, only the first laser light irradiation unit 41 is used to heat and fix the unfixed image TG.
Further, when high grade G ₂ glossiness of high gloss mode HG is selected, as shown in FIG. 16 (b), the first laser beam irradiation section 41 and the second laser beam irradiation section 42 Is used to heat and fix the unfixed image TG.
Further, if the lower grade G ₁ gloss of the high gloss mode HG is selected, as shown in FIG. 16 (c), using only the second laser beam irradiation unit 42, than Grade G ₁ The unfixed image TG is heated and fixed with the irradiation energy that suppresses the irradiation energy of the first laser beam irradiation unit 41.
According to this aspect, for the high gloss mode HG, by using the first laser light irradiation unit 41 and the second laser light irradiation unit 42 in combination, in particular, the irradiation energy of the second laser light source 42a is reduced. The glossiness in the high gloss mode can be variably adjusted without changing it.
Of course, the aspect of this embodiment and the aspect of Embodiment 2 may be used in combination.

Embodiment 4
FIG. 17A is an explanatory diagram showing an outline of the fixing device according to the fourth embodiment.
In the drawing, the irradiation region R ₁ by the first laser light irradiation unit 41 is included in the downstream side in the transport direction of the recording material 10 in the irradiation region R ₂ by the second laser light irradiation unit 42.
According to this aspect, when the high gloss mode HG is selected, the laser beams from the first laser beam irradiation unit 41 and the second laser beam irradiation unit 42 are not yet determined on the recording material 10 without a gap. Since the image TG is irradiated, it is preferable in that heat loss required for heat fixing can be suppressed.
Further, the layout example of the first laser light irradiation unit 41 and the second laser light irradiation unit 42 is not limited to the mode shown in FIG. 17A, but as shown in FIG. 17B. In addition, for example, the first laser beam irradiation unit 41 is arranged to be inclined by an angle θ with respect to the conveyance direction of the recording material 10, and the first laser beam irradiation unit 42 is in the vicinity of the center in the irradiation region R ₂ . It may be arranged so as to include the irradiation region R ₁ of the laser light irradiation unit 41.
Further, in each of Embodiments 1 to 4, the second laser light irradiation unit 42 is disposed upstream of the first laser light irradiation unit 41 in the conveyance direction X of the recording material 10. As shown in FIG. 17C, the second laser light irradiation unit 42 is disposed downstream of the first laser light irradiation unit 41 in the conveyance direction X of the recording material 10. May be. Is this case, as shown in FIG. 17 (c), adjacent without opening between the irradiation region R ₂ of the irradiation region R ₁ and the second laser beam irradiation section 42 of the first laser beam irradiation section 41 Alternatively, as shown in FIGS. 17 (a) and 17 (b), it is preferable to arrange both irradiation regions R ₁ and R ₂ so as to overlap at least partly or entirely.

Embodiment 5
FIG. 18A is an explanatory diagram showing an outline of the fixing device according to the fifth embodiment.
In the figure, the basic configuration of the fixing device is substantially the same as that of the first embodiment, but the control method of the control device 50 is different from that of the first embodiment.
In the present embodiment, as in the first embodiment, the control device 50 inputs image data to be imaged by the image creating device 21 through the image data input device 61, and based on this image data, the image unit / non- The image part discrimination process 51 is executed.
For example, as shown in FIG. 18B, the image portion / non-image portion discrimination processing 51 selects an image portion in which an image by a toner exists among the unfixed images TG formed on the recording material 10 as TG ₁ , Assuming that TG ₂ and non-image portions where no toner image exists are N _{1 to} N ₃ , the image data input from the image data input device 61 is read as shown in FIG. Thus, the image portions TG ₁ and TG ₂ and the non-image portions N _{1 to} N ₃ are discriminated.
Then, the control unit 50, as shown in FIG. 19, further perform the glossiness determination process 52 for the image portion, for example, the image portion TG ₁ is determined to require a high gloss if a color image area, While the high gloss mode HG is determined, for example, if the image portion TG ₂ is a highlight image or black image region, it is determined that the gloss level is low, and the low gloss mode LG is determined.
On the other hand, as shown in FIG. 19, the control device 50 determines the low gloss mode LG for the non-image portions N _{1 to} N ₃ .
Therefore, according to the present embodiment, for the image portions TG ₁ and TG _{2 of the} unfixed image TG on the recording material 10, when the high gloss mode HG is selected according to the determined gloss level. As shown by a solid line in FIG. 20A, an irradiation operation (short-time irradiation + long-time irradiation) by laser light using the first laser light irradiation unit 41 and the second laser light irradiation unit 42 is performed. When the low gloss mode LG is selected, as shown by a dotted line in FIG. 20A, an irradiation operation (short-time irradiation) with a laser beam using only the first laser beam irradiation unit 41 is performed. The image portions TG ₁ and TG ₂ are heat-fixed.
On the other hand, since the low gloss mode LG is selected for the non-image portions N _{1 to} N ₃ among the unfixed images TG on the recording material 10, as shown in FIG. The laser beam irradiation operation (short-time irradiation) using only the laser beam irradiation unit 41 is performed, and the isolated toner T ′ adhering to the non-image portions N _{1 to} N ₃ is heated and fixed.
In this example, the low-gloss mode LG for the image portions TG ₁ , TG ₂ and the non-image portions N _{1 to} N ₃ is an irradiation intensity that can fix the laser light from the first laser light irradiation unit 41 or If they are selected as having an irradiation time, both may be set to the same level or different levels.

<Fixable conditions for isolated toner in non-image area>
Now, when the irradiation time (ms) and the irradiation energy density (J / cm ² ) are changed for the laser beam from the first laser beam irradiation unit 41, the conditions under which the isolated toner in the non-image area can be fixed are examined. As shown in FIG. 21, it was confirmed that the isolated toner can be fixed in the region on the left side of the boundary E that increases in a curved line from the region with a short irradiation time to the region with a long irradiation time.
On the other hand, when the conditions under which the surface image formed by the toner group connected to the surface shape of the image portion can be fixed in the low gloss mode were examined, the surface in the region above the boundary S along the substantially constant irradiation energy regardless of the irradiation time. It was confirmed that the image can be fixed.
In FIG. 21, for example, in a region I surrounded by a dotted line having a laser beam irradiation time of, for example, about 1 ms or more by the first laser beam irradiation unit 41, the boundary line K where the isolated toner can be fixed is the boundary line where the surface image can be fixed Irradiation energy is higher than Q, and conversely, in the region II surrounded by the one-dot chain line whose laser beam irradiation time by the first laser beam irradiation unit 41 is shorter than about 1 ms, for example, the isolated toner can be fixed. The boundary line K has a lower irradiation energy than the boundary line Q where the surface image can be fixed.
As described above, it is presumed that the fixing conditions for the isolated toner and the surface image are different between the region I and the region II as follows.

As shown in FIG. 22A, since the isolated toner T ′ on the recording material 10 has a large area in contact with the outside air, for example, the heat quantity Q of the laser beam by the first laser light irradiation unit 41 works on the isolated toner T ′. in addition to the amount of heat Q _1, there is a quantity of heat ΔQ which is consumed in the surrounding atmosphere. That is, the relationship of Q≈Q ₁ + ΔQ is satisfied.
Here, when the short-time irradiation method (region I in FIG. 21) with a relatively long irradiation time is adopted as the laser light from the first laser light irradiation unit 41, the amount of heat ΔQ consumed by the surrounding outside air is since increasing the quantity of heat Q of the laser beam by the first laser beam irradiation unit 41 often require, that amount necessary to set a high irradiation energy W ₁₁ of the laser beam by the first laser beam irradiation section 41 It is.
On the other hand, when the short-time irradiation method (region II in FIG. 21) with a short irradiation time is adopted as the laser light from the first laser light irradiation unit 41, the irradiation energy W is larger than that in the case of the region II. _11, the amount of heat ΔQ consumed by the ambient air is reduced, and even if the irradiation energy W ₁₁ is low, the amount of heat Q ₁ received by the isolated toner T ′ exceeds the amount of heat ΔQ consumed by the ambient air. The toner reaches a low viscosity state at a high temperature and can be fixed.
On the other hand, as shown in FIG. 22B, when the surface laser beam TG on the recording material 10 is irradiated with the laser beam from the first laser beam irradiation unit 41, the first laser beam irradiation unit. the quantity Q of the laser beam by 41 in addition to the heat quantity Q ₁ acting on the toner present in the irradiated target area of the face image TG, there are heat Q ₂ to which is transmitted to the surroundings. That is, the relationship of Q≈Q ₁ + Q ₂ is satisfied.
Here, when the short-time irradiation method (region I in FIG. 21) having a relatively long irradiation time is adopted as the laser light by the first laser light irradiation unit 41, the laser by the first laser light irradiation unit 41 is used. since the heat quantity Q of light is directly or indirectly effective use for face image TG, the first irradiation energy W ₁₂ of the laser beam by the laser beam irradiation unit 41 irradiates the energy required for an isolated toner T ' sufficient at a lower level than the W _11.
On the other hand, when the short-time irradiation method (region II in FIG. 21) with a short irradiation time is adopted as the laser light from the first laser light irradiation unit 41, the irradiation energy W ₁₁ required for the isolated toner T ′. it is possible to set the lower, in the case of the surface image TG, since the heat capacity per unit area is large, may occur isolated toner T 'in a fixable irradiation energy W ₁₁ in impossible fixing case. Therefore, it is preferable as the irradiation energy W ₁₂ necessary to the plane image TG to select a higher level than the irradiation energy W ₁₁ required for an isolated toner T '.
Therefore, for example, as shown in FIG. 23, in the irradiation time condition of the region I in FIG. 21, when the conditions for fixing the laser beam by the first laser beam irradiation unit 41 for the isolated toner and the surface image are selected, the isolation is selected. A value higher than the irradiation energy for the surface image may be selected as the irradiation energy for the toner.
On the other hand, as shown in FIG. 24, for example, in the irradiation time condition of the region II in FIG. 21, when the conditions for fixing the laser beam by the first laser beam irradiation unit 41 to the isolated toner and the surface image are selected, A value lower than the irradiation energy for the surface image may be selected for the irradiation energy for the toner.

Further, in the present embodiment, for the heat fixing control processing of the fixing device by the control device 50, the image portion / non-image portion is determined based on the image data, and the glossiness determination processing is performed on the image portion. However, the glossiness determination processing for the image portion is not limited to this, and it is needless to say that the modes shown in Embodiments 1 to 4 may be selected as appropriate.
For example, as shown in the first embodiment, the type of recording material may be considered in advance when performing the glossiness determination process for the image portion.
Further, as shown in the second embodiment and the modified embodiment 2-1, a plurality of grades may be classified for the high gloss mode and the low gloss mode. At this time, the laser beam irradiation intensity may be made variable for the first laser beam irradiation unit 41, while the laser beam irradiation intensity may be made variable for the second laser beam irradiation unit 42. Alternatively, the irradiation time of the laser beam may be variable.
Furthermore, as shown in the third embodiment, when the high gloss mode is graded, both the first laser light irradiation unit 41 and the second laser light irradiation unit 42 are used for high gloss levels. For the low gloss level, only the second laser light irradiation unit 42 may be used.
In the aspect in which the low gloss mode is graded, the first laser light irradiation unit 41 may be used under the conditions corresponding to the low gloss level for the non-image portion.

Example 1
The fixing device according to the first embodiment is used as Example 1, and the recording material 10 is coated paper (in this example, OKTC + 027 paper manufactured by Fuji Xerox Co., Ltd.) and plain paper (J paper manufactured by Fuji Xerox Co., Ltd.). As a condition for the low gloss mode, the first laser light irradiation unit 41 is irradiated at 1 ms 0.8 J / cm ^{2. As} a condition for the high gloss mode, the first laser light irradiation unit 41 is 1 ms 0.8 J / cm ^2. + When the second laser light irradiation part 42 was irradiated at 24 ms 2.0 J / cm ² , the result shown in FIG. 25 was obtained. In this example, the heat fixing target is an image with a coverage of 100%.
According to FIG. 25, in the case of coated paper, the gloss level is increased by about 6 times in the low gloss mode and in the high gloss mode, whereas in the case of plain paper, the low gloss mode is set. In the high gloss mode, it is understood that the gloss level changes only about twice.
For this reason, when the recording material 10 is smooth glossy paper such as coated paper, it is understood that the method of the present application is extremely effective in the high gloss mode.

DESCRIPTION OF SYMBOLS 1 ... 1st laser beam irradiation part, 1a ... Laser light source, 1b ... Condensing part, 2 ... 2nd laser light irradiation part, 2a ... Laser light source, 2b ... Condensing part, 3 ... Determination means, 4 ... Control means, 5 ... recording material, 6 ... conveying means 7 ... imaging unit, 8 ... fixing device, a ... high gloss, B ... low gloss, TG ... unfixed image, t 1 _... of the first laser beam Irradiation time, t ₂ ... irradiation time of the second laser beam

Claims (16)

A first laser beam having a predetermined intensity is irradiated on a non-fixed image formed by a heat-fixable imaging material formed on a moving recording material for a predetermined heat-fixable time. A laser beam irradiation unit;
A second laser beam irradiation unit that irradiates the unfixed image with a second laser beam having a predetermined intensity for a time longer than the irradiation time of the first laser beam irradiation unit;
Determination means for determining a gloss level required for an image of an unfixed image on the recording material;
Control for controlling the first laser light irradiation unit and the second laser light irradiation unit so as to change the irradiation energy of at least the second laser light irradiation unit based on the glossiness determined by the determination means. Means,
A fixing device comprising: The fixing device according to claim 1.
The control means performs a laser light irradiation operation by the first laser light irradiation unit when the glossiness determined by the determination means is a low glossiness that is lower than a predetermined level, and When the glossiness determined in this way is higher than the low glossiness, the first laser beam irradiation unit and the second laser beam irradiation unit perform the laser beam irradiation operation so as to perform the first laser beam irradiation operation. A fixing device that controls the laser beam irradiation unit and the second laser beam irradiation unit. The fixing device according to claim 1 or 2,
The start position of the laser light irradiation area by the second laser light irradiation section is positioned at least upstream in the moving direction of the recording material as compared to the start position of the laser light irradiation area by the first laser light irradiation section. A fixing device characterized by the above. The fixing device according to any one of claims 1 to 3,
The fixing device according to claim 1, wherein the irradiation region of the laser beam by the first laser beam irradiation unit is at least partially included in the irradiation region of the second laser beam by the second laser beam irradiation unit. The fixing device according to any one of claims 1 to 4,
The determination means can determine a high glossiness divided into a plurality of levels,
The control means increases at least one of the plurality of high glossiness levels, that is, the higher the glossiness level, the stronger the laser beam irradiation intensity by the second laser beam irradiation unit or the longer the laser beam irradiation time. A fixing device comprising: an adjustment unit capable of variably adjusting at least one or both of the irradiation intensity and the irradiation time of the laser beam by the second laser beam irradiation unit so as to implement one or both. The fixing device according to any one of claims 1 to 5,
The determination means can determine a low glossiness divided into a plurality of levels,
The control means includes a laser beam emitted from the first laser beam irradiating unit so as to increase the intensity of laser beam emitted from the first laser beam irradiating unit as the gloss level is higher among a plurality of low gloss levels. A fixing device having an adjustment unit capable of variably adjusting the irradiation intensity of the light. The fixing device according to claim 1,
The determination means can determine a high glossiness divided into a plurality of levels,
When the determination means determines the glossiness belonging to a high level among a plurality of high glossiness levels, the control means irradiates laser light from the first laser light irradiation section and the second laser light irradiation section. When the determination means determines the glossiness belonging to a low level among a plurality of high glossiness levels, the laser by the second laser light irradiation unit is used without using the first laser light irradiation unit. A fixing device that controls the first laser light irradiation unit and the second laser light irradiation unit so as to perform a light irradiation operation. The fixing device according to any one of claims 1 to 7,
The determination unit includes an image information acquisition unit that acquires image information about an unfixed image on the recording material, and an image of the unfixed image on the recording material based on the image information acquired by the image information acquisition unit. A fixing device characterized by determining the glossiness required for the apparatus. The fixing device according to claim 8.
The control means applies the first laser beam irradiation to an image whose glossiness obtained based on the image information acquired by the image information acquisition means is higher than a predetermined level. Controlling the first laser light irradiation unit and the second laser light irradiation unit so as to perform the laser light irradiation operation by the second laser light irradiation unit in addition to the laser light irradiation operation by the unit. A fixing device characterized by the above. The fixing device according to claim 9.
The control means, for an image whose glossiness obtained based on the image information acquired by the image information acquisition means is higher than a predetermined level, the higher the glossiness, the higher the glossiness. A fixing device that performs at least one of or both of increasing the irradiation intensity of the laser beam by the second laser beam irradiation unit or extending the irradiation time of the laser beam. The fixing device according to claim 8.
The determination means determines an image part and a non-image part based on the image information acquired by the image information acquisition means, and determines a glossiness required for the image part.
The control unit controls the first laser irradiation unit and the second laser irradiation unit based on the glossiness determined by the determination unit for the image unit determined by the determination unit,
The first laser irradiation unit and the second laser irradiation unit perform the laser light irradiation operation by the first laser irradiation unit without using the second laser light irradiation unit for the non-image portion determined by the determination unit. The fixing device characterized by controlling the laser irradiation part of. The fixing device according to claim 11.
The control means is provided for an image part whose glossiness obtained is higher than a predetermined level among the image parts determined based on the image information acquired by the image information acquisition means. The fixing is characterized in that at least one or both of increasing the laser beam irradiation intensity by the second laser beam irradiation unit and / or extending the laser beam irradiation time as the glossiness increases is performed. apparatus. The fixing device according to claim 11 or 12,
The control means controls the first laser light irradiation unit so that the irradiation intensity with respect to the image part and the non-image part is different with respect to the irradiation intensity of the laser light by the first laser light irradiation part. Fixing device to do. The fixing device according to claim 13.
The control device controls the first laser light irradiation unit so that the irradiation intensity with respect to the non-image part is weaker than the image part with respect to the irradiation intensity of the laser light by the first laser light irradiation part. A fixing device characterized. The fixing device according to any one of claims 1 to 7,
The determination means determines whether or not the recording material is of a type having a highly glossy surface portion, and the glossiness required for the image when the recording material is of a type having a highly glossy surface portion can be determined in advance. The fixing device is characterized in that the glossiness is determined to be higher than the standard. Conveying means for conveying the recording material;
An image forming means for forming an unfixed image by an image forming material capable of being heat-fixed on a recording material conveyed by the conveying means;
The fixing device according to any one of claims 1 to 15, which heat-fixes the unfixed image formed by the image forming means.
An image forming apparatus comprising:

Images