JP4480376B2 - Recording device - Google Patents

Description

  The present invention relates to a recording apparatus using a recording medium on which recording is performed by light exposure.

  Conventionally, a recording medium in which a surface of a thermosensitive coloring layer is coated with a light-to-heat conversion material is held by a recording medium holding unit, and the held recording medium is exposed with light emitted from a recording unit having a light source and a lens, 2. Description of the Related Art A recording apparatus is known that records information by coloring an exposed portion. Known recording medium holding means include an outer exposure drum, an inner exposure drum, a conveyor belt, a chain conveyor, a platen roller, and the like.

  In a recording apparatus having such a recording medium holding means and a recording means, light (recording light) exposed from the recording means is perpendicularly incident on a recording medium that travels while being held by the recording medium holding means. The recording means is arranged to avoid this. The reason for this is to prevent the reflected light from the recording medium of the recording light from returning to the recording means and adversely affecting the recording means. Therefore, the recording light from the recording means is exposed to the recording medium from a position inclined with respect to the normal direction of the peripheral surface of the recording medium. At this time, if the distance between the recording means and the recording medium varies, the recording position on the recording medium shifts according to the inclination.

  By the way, in a recording apparatus having a recording means having a light source and a lens, if the distance between the recording medium (or the photosensitive member) and the recording means varies, the focal position shifts and the recorded image quality deteriorates. Conventionally, in order to prevent the deviation of the focal position, the invention is such that the distance between the photosensitive member and the recording means is measured, and the recording means is moved so that the focal position becomes an appropriate position from the measurement result. It is known (see, for example, Patent Document 1).

JP 09-281383 A

  In the case where the recording medium is exposed to the recording light from the position inclined with respect to the normal direction of the circumferential surface of the recording medium, the distance between the recording means and the recording medium fluctuates, so the recording medium according to the inclination Even if the recording position is shifted, the value of the shift amount itself is small, so that there is no problem when recording is performed by a single recording means. However, when high-speed and high-precision recording is performed using a plurality of recording means, this is a problem that cannot be ignored.

  The invention disclosed in Patent Document 1 adjusts the focal position, and does not adjust the recording position deviation with respect to the recording medium.

  An object of the present invention includes a recording medium holding unit that holds a recording medium, and a plurality of recording units that are provided with a light source and a lens so as to be opposed to the recording medium. In the case of dividing and recording, even if the recording medium holding means is eccentric or the held recording medium is lifted from the recording medium holding means, the recording position deviation on the recording medium is not generated. Is to prevent.

The recording apparatus according to the first aspect of the present invention includes a rotatable cylindrical drum that holds a recording medium on which recording is performed by light exposure, a light source, and a lens, and proceeds while being held by the drum. A plurality of recording means arranged along the width direction of the recording medium orthogonal to the traveling direction of the medium, and exposing light onto the recording medium from a position inclined with respect to the normal direction of the peripheral surface of the recording medium; A distance detecting means provided for each recording means, for detecting a distance between the recording means and the recording medium held on the drum during one rotation of the drum; and comprising an adjusting means for adjusting the exposure start timing of said recording means according to a detection result, wherein the distance detecting means, a distance between the recording means and the recording medium at the time of rotation of the first rotation of the drum The obtained detection result is stored in the storage unit, and the driving is stopped when the drum rotates after the second round, and the adjusting means is stored in the storage unit during the second and subsequent rotations of the drum. The exposure start timing by the recording means is adjusted according to the detection result .

Therefore, recording on the recording medium can be performed by exposing the recording medium with a plurality of recording means arranged along the width direction of the recording medium held and moved by the recording medium holding means. At the time of recording, by using a plurality of recording means, the exposure width of each recording means is reduced, and the width for swinging the lens or the like is reduced so that light scans within the exposure width of each recording means. And high-speed and high-precision recording becomes possible. When the distance between the recording means and the recording medium fluctuates due to the eccentricity of the recording medium holding means or the lift of the held recording medium, the exposure start timing according to the detection result of the distance detecting means that detects the change in the distance As a result, the recording position shift on the recording medium is prevented. Also, if the data of the detection result from the distance detection means is only for one revolution of the drum, this is stored, so that the detection result at the first revolution of the drum is obtained for every revolution of the drum (second revolution). Since the driving time of the distance detecting means can be reduced by stopping the driving of the distance detecting means during the second and subsequent rotations of the drum, the signal processing can be simplified and the energy can be saved. Can do.

According to a second aspect of the present invention, in the recording apparatus according to the first aspect of the present invention, the recording apparatus further includes a storage unit that stores a function that defines a relationship between a detection result of the distance detection unit and an adjusted exposure start timing.

  Therefore, when the distance detection unit detects the distance between the recording unit and the recording medium, the exposure start timing is determined using a function stored in the storage unit according to the detection result. For this reason, recording with no recording position deviation can be performed by simple signal processing.

According to a third aspect of the present invention, in the recording apparatus according to the first or second aspect , the distance detecting means is provided on the same substrate as the recording means.

  Therefore, the distance between the recording means and the recording medium can be accurately detected with a simple configuration.

According to a fourth aspect of the present invention, in the recording apparatus according to any one of the first to third aspects, the distance detecting means is disposed in a non-contact manner with respect to the recording medium held on the drum .

  Therefore, it is possible to detect the distance between the recording means and the recording medium without causing noise or recording medium wear.

According to a fifth aspect of the present invention, in the recording apparatus according to any one of the first to fourth aspects, the plurality of recording units are parallel to the surface of the recording medium held on the drum and the recording medium advances. They are arranged in a row in a direction orthogonal to the direction.

Accordingly, the influence of the drum rotation unevenness acts on all the recording means in the same manner, so that the recording position deviation between the recording means is prevented.

According to a sixth aspect of the present invention, in the recording apparatus according to the fifth aspect , all the light from the recording means is incident on the recording medium held on the drum from the same direction.

  Accordingly, since the incident angles of the recording light from the recording units to the recording medium are substantially equal, the recording position shift between the recording units is reduced.

According to a seventh aspect of the present invention, in the recording apparatus according to the fifth or sixth aspect , the function defining the relationship between the detection result from the distance detection means and the adjusted exposure start timing is the same in all the recording means. is there.

  Therefore, the exposure start timing for a plurality of recording means can be determined by simple signal processing.

According to an eighth aspect of the present invention, in the recording apparatus according to any one of the first to fourth aspects, the plurality of recording means are parallel to the surface of the recording medium held by the drum and perpendicular to the traveling direction of the recording medium. Are arranged in a staggered pattern in two or more rows.

  Therefore, it is possible to further reduce the recording area of each recording unit, thereby preventing the occurrence of a recording position shift and performing higher speed recording.

According to a ninth aspect of the present invention, in the recording apparatus according to the eighth aspect , all the light from the recording means in the same row is incident on the recording medium held on the drum from the same direction.

  Accordingly, since the incident angles of the recording light from the recording medium means in the same row to the recording medium become substantially equal, the recording position shift between the recording means in the same row is reduced.

According to a tenth aspect of the present invention, in the recording apparatus according to the eighth or ninth aspect , the recording position on the recording medium held on the drum by the plurality of recording means arranged in a staggered manner in two or more rows is the recording position. They are arranged in a line in a direction orthogonal to the traveling direction of the medium.

  Therefore, the occurrence of the recording position deviation on the recording medium caused by arranging the recording means in two or more rows in a staggered manner is reduced.

According to an eleventh aspect of the present invention, in the recording apparatus according to any one of the eighth to tenth aspects, the function defining the relationship between the detection result from the distance detection means and the adjusted exposure start timing is within the same column. In the recording means.

  Therefore, the determination of the exposure start timing for a plurality of recording means in the same column can be performed by simple signal processing.

According to the first aspect of the present invention, when the distance between the recording means and the recording medium is fluctuated due to the eccentricity of the drum or the lift of the held recording medium, the detection of the distance detecting means that detects the change in the distance. The exposure start timing can be adjusted according to the result, and the recording position shift on the recording medium can be prevented. Also, if the data of the detection result from the distance detection means is only for one revolution of the drum, this is stored, so that the detection result at the first revolution of the drum is obtained for every revolution of the drum (second revolution). Since the driving time of the distance detecting means can be reduced by stopping the driving of the distance detecting means during the second and subsequent rotations of the drum, the signal processing can be simplified and the energy can be saved. Can do.

According to the second aspect of the present invention, it is possible to perform recording with no recording position deviation by simple signal processing.

According to the third aspect of the invention, the distance between the recording means and the recording medium can be accurately detected with a simple configuration.

According to the fourth aspect of the present invention, it is possible to detect the distance between the recording means and the recording medium without causing noise, wear of the recording medium, or the like.

According to the fifth aspect of the present invention, even when recording on a wide recording medium, it is possible to perform recording at high speed and without a recording position shift.

According to the sixth aspect of the present invention, it is possible to reduce the recording position deviation between the recording units.

According to the seventh aspect of the present invention, it is possible to determine the exposure start timing for a plurality of recording means by simple signal processing.

According to the eighth aspect of the present invention, it is possible to further reduce the recording area of each recording unit, prevent occurrence of a recording position shift, and perform higher speed recording.

According to the ninth aspect of the present invention, it is possible to reduce the recording position deviation between the recording units located in the same row.

According to the tenth aspect of the present invention, it is possible to reduce the occurrence of the recording position shift on the recording medium caused by arranging the recording means in two or more rows.

According to the eleventh aspect of the present invention, the determination of the exposure start timing for a plurality of recording means in the same row can be performed by simple signal processing.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing a recording apparatus, FIG. 2 is a side view thereof, FIG. 3 is an explanatory diagram of coloring / decoloring phenomenon of a recording medium, and FIG. 4 is a side view showing another example of a paper feeding apparatus provided in the recording apparatus. FIG. 5, FIG. 5 is a plan view showing details of the recording means, FIG. 6 is a side view for explaining the recording position shift caused by the eccentricity of the drum and the lifting of the recording medium, and FIG. 7 shows the arrangement of the distance detecting means and the recording means. FIG. 8 is a block diagram showing an outline of a circuit configuration for preventing a recording position shift, FIG. 9 is a flowchart for explaining adjustment of exposure start timing, and FIG. 10 is for explaining a function for defining exposure start timing. FIG.

  As shown in FIGS. 1 and 2, the recording apparatus P <b> 1 of the present embodiment includes a cylindrical drum 2 that is a recording medium holding unit for holding the recording medium 1, and a drive for driving the drum 2. A source 3, a recording medium supply unit 4 that supplies the recording medium 1, and a plurality of recording means 8 that are means for recording information on the recording medium 1 are provided. Each recording unit 8 includes a light source 5, a lens 6 for converging light emitted from the light source 5, and a substrate 7 on which the light source 5 and the lens 6 are mounted. As the drive source 3, a stepping motor or a servomotor is used because highly accurate position control is required for the rotational position of the drum 2.

  In this example, the recording medium supply unit 4 includes a supply shaft 9 that supports the recording medium 1 wound in a roll shape, a pair of conveyance rollers 10 that pulls out the recording medium 1 from the supply shaft 9, and a recording medium that has been drawn out. 1 has a recording medium sensor 11 whose on / off operation is switched when the leading edge of 1 is reached, and a cutter 12 which cuts the drawn recording medium 1 into a desired size. The cutter 12 cuts the recording medium 1 when driven by the rail-shaped guide 13 and driven. As the recording medium sensor 11, a reflection type or transmission type photo interrupter is generally used, or a detection method with a filler is often used.

  The recording medium supply unit 4 is configured as shown in FIGS. 1 and 2 because the recording medium 1 is often in the form of a roll. However, when the recording medium 1 having a specified size is used, the recording medium supply unit 4 Instead of 4, a recording medium supply unit 4a as shown in FIG. The recording medium supply unit 4a is configured to sequentially draw out the recording medium 1 of a specified size stacked on the recording medium tray 4b from the upper layer by the paper feeding roller 4c and deliver it to the conveying roller 10.

  A clamp (not shown) that holds the cut recording medium 1 wound around the outer periphery of the drum 2 is provided on the outer periphery of the drum 2. A drum gear 2 b is fixed to the rotation shaft 2 a of the drum 2, and the drum gear 2 b and a motor gear 3 a connected to the drive source 3 are engaged with each other.

  The recording medium 1 has a recording layer that produces heat-sensitive color, and is a medium on which information is recorded by being exposed to light such as laser light, and the recorded information can be optically read. Examples of the recording medium 1 include a write-once type such as Ricoh Co., Ltd., TF3100-S, and TF3101-F. Further, the recording medium 1 includes a rewritable format described in the following description.

The rewritable recording medium 1 described here can form a relatively colored state and a decolored state depending on the manner of heating and cooling after heating. This basic coloring / decoloring phenomenon will be described with reference to FIG. FIG. 3 shows the relationship between the color density (vertical axis) and the temperature (horizontal axis) of the composition (developer, color former) of the recording medium 1. When the temperature of the composition initially in the decolored state (A) is raised, color development occurs at the temperature T ₁ at which melting starts, and the molten color state (B) is obtained. When rapidly cooled from the melt color state (B), the color state can be lowered to room temperature and a solid color state (C) is obtained. Whether or not this color development state is obtained depends on the rate of temperature decrease from the molten state. In slow cooling, the color disappears in the process of temperature decrease, and the same color disappearance state (A) or rapid color development state (C ) A relatively low concentration state is formed. On the other hand, quenched coloring state (C) a decoloring happened again the temperature was raised gradually lower than the coloring temperature the temperature T ₂ (E from D), returns the beginning when the temperature decreases from here to the same decolored state (A). The actual color developing temperature and color erasing temperature vary depending on the combination of the developer and color former used, and can be selected according to the purpose. Further, the density of the melt coloring state and the coloring density when rapidly cooled are not necessarily the same and may be different.

  Therefore, when information is written on the rewritable recording medium 1, color recording is performed by heating to a temperature at which it is melted and mixed by a laser light source, a thermal head or the like and then rapidly cooling. In addition, there are two methods of erasing: a method of slowly cooling from a heated state and a method of heating to a temperature slightly lower than the coloring temperature. However, the two methods are the same in the sense that the developer and the color former are phase-separated, or at least one of the developer and the color developer is temporarily maintained at a temperature at which crystallization occurs. The reason for quenching when developing the color is to prevent the temperature from being maintained at the above phase separation or crystallization temperature. However, rapid cooling and slow cooling here are relative to one composition, and the boundary changes depending on the combination of the color former and the developer. Therefore, it is necessary to control the temperature according to the composition used. There is.

  As described above, the recording unit 8 includes the light source 5, the lens 6, and the substrate 7, and a plurality of the recording units 8 are arranged along the direction of the center line of the drum 2. As the light source 5, a light emitting diode or a laser diode is used, and a light source driving circuit 14 is connected (see FIG. 5). The lens 6 functions to converge the light emitted from the light source 5 and expose the recording medium 1 on the drum 2, and is connected to a swing mechanism 15 (see FIG. 5). The lens 6 is oscillated by driving the oscillating mechanism 15, and a predetermined recording area on the recording medium 1 which the recording means 8 is responsible for is scanned. “A” shown in FIG. 5 indicates the range of the recording area on the recording medium 1 which is handled by one recording means 8. The lens 6 is swung by the rocking mechanism 15 so that the light converged by the lens 6 is scanned in the recording area “a”.

  In the recording apparatus P1 of the present embodiment, since the main purpose is mainly to create a printing plate or a block, it is indispensable to realize high-density and high-precision recording, and , High speed recording must be realized. For this purpose, a method such as providing a plurality of recording means 8 is often used. By doing so, it is possible to easily cope with a wide recording medium 1. In that case, the recording position shift by the some recording means 8 becomes a problem.

  A variation in the distance between the recording unit 8 and the recording medium 1 can be cited as a factor that causes the recording position deviation. Generally, the recording light from the recording means 8 is exposed on the recording medium 1 from a position inclined with respect to the normal direction of the peripheral surface of the recording medium 1 which is wound around the drum 2 and travels. The reason for this is to prevent the reflected light from the recording medium 1 of the recording light from returning to the recording means 8 and adversely affecting the recording means 8. Therefore, if the distance between the recording means 8 and the recording medium 1 varies due to the eccentricity of the drum 2 or the floating of the recording medium 1, a recording position shift corresponding to the inclination of the recording light occurs. . With respect to this recording position deviation, when only one recording means 8 is used, although there is a recording position deviation, it does not seem to be a big problem because it does not visually recognize the deviation. When there are a plurality of recording means 8, there may be a problem of a misalignment amount at the boundary line of the portion of the image of each recording means 8. In order to solve these problems, the present embodiment has the following configuration.

  As shown in FIG. 7, a distance detection unit 16 is provided on the same substrate 7 as the recording unit 8, and the distance detection unit 16 can always detect the distance between the recording unit 8 and the recording medium 1. As a method of the distance detection means 16, a laser Doppler method, a CD optical pickup method, an ultrasonic method, etc. are generally used. What is common to both is that they are not in contact with the recording medium 1. By doing so, problems such as frictional noise and wear of the recording medium 1 can be avoided. Further, a method of detecting the distance using the reflected light from the recording medium 1 may be used. In that case, simplification and cost reduction of the apparatus can be realized.

  When the distance detecting unit 16 detects that the distance between the recording unit 8 and the recording medium 1 has changed, the exposure start timing of the recording unit 8 is set in order to correct the recording position shift that occurs according to the detected amount. It is necessary to correct.

  The distance detection means 16 is set so as to detect the distance of the portion slightly upstream from the position where the recording means 8 performs recording as viewed from the traveling direction of the recording medium 1. The distance is detected by the distance detector 16 where t is the distance between the portion of the recording medium 1 where the distance to the recording means 8 is detected and the portion where recording is performed, and v is the linear velocity of the recording medium 1. Thereafter, recording is performed at a portion where the distance from the recording means 8 is detected when the time t / v has elapsed. Therefore, the exposure start timing correction amount corresponding to the distance signal detected by the distance detection means 16 is calculated during the time t / v, and the timing corresponding to the correction amount is based on when the time t / v has elapsed. I try to record. By doing so, even when the distance between the recording means 8 and the recording medium 1 fluctuates, it becomes possible to detect in real time and always perform recording with no recording position deviation.

  FIG. 8 is a block diagram showing an outline of a circuit configuration for preventing a recording position shift. The distance detecting means 16 is connected to the adjusting means 17, and the light source driving circuit 14 is connected to the adjusting means 17. In the adjusting means 17, the adjustment time of the exposure start timing by the recording means 8 is calculated according to the detection result of the distance detecting means 16. A storage unit 18 that stores a function that defines the relationship between the detection result of the distance detection unit 16 and the exposure start timing to be adjusted is connected to the adjustment unit 17.

  FIG. 9 is a flowchart for explaining the adjustment of the exposure start timing. When a distance signal is input from the distance detection means 16 (step S1), a calculation based on a function stored in the storage unit 18 is performed based on the distance signal, and an exposure start timing correction amount δ is calculated ( Step S2). After the correction amount δ is calculated, the exposure is started after waiting for a predetermined time “t / v + δ” after the distance signal from the distance detection means 16 is input (step S3). .

FIG. 10 is an explanatory diagram of a function for obtaining the exposure start timing correction amount “δ”. The amount of change in distance detected by the distance detection means 16 is “p”, the inclination angle of the exposure light incident on the recording medium 1 from the recording means 8 with respect to the normal direction of the peripheral surface of the recording medium 1 is “θ”, and recording When the linear velocity of the medium 1 is “v”, the writing position shift amount “q” on the recording medium 1 is
It can be expressed as “q = p · tanθ”
Therefore, the exposure start timing correction amount “δ” is
“Δ = q / v = p / v · tan θ”.

Only one distance detecting means 16 may be provided, but two or more distance detecting means 16 may be provided. By providing two or more, even when the recording means 8 and the drum 2 are installed at an inclination, it is possible to detect it and perform a more accurate distance detection. That is, by providing at least two distance detecting means, it is possible to detect a change in the distance between the recording means and the recording medium with high accuracy, and to prevent a recording position shift on the recording medium.

  A second embodiment of the present invention will be described with reference to FIGS. Note that the same portions as those described in FIGS. 1 to 10 are denoted by the same reference numerals, and description thereof is also omitted. In the recording apparatus P2 of the present embodiment, one distance detecting means 16 is provided for each of the plurality of recording means 8 arranged along the axial direction of the drum 2.

As a result, the exposure start timing can be adjusted in each recording means 8. For example, as shown in an exaggerated manner in FIG. 11, the ratio of the surface shake of the drum 2 is in the recording area that each recording means 8 is responsible for. Even when the drums 2 are scattered and distorted, it is possible to accurately detect the distance in each recording area, and the exposure start timing can be adjusted in each recording means 8 according to the detection result. That is, the distance detecting means is provided for each recording means, so that the distance between the recording means and the recording medium in the recording area that each recording means is responsible for can be detected. The exposure start timing is adjusted for each recording means. For this reason, even if the installation and processing accuracy of the recording means and the recording medium holding means are low, the recording position shift on the recording medium is prevented.

  As shown in FIG. 12, the plurality of recording means 8 are arranged in a line in the axial direction of the drum 2. In this way, a plurality of recording means 8 can be used efficiently, high-speed recording is possible even on a wide recording medium 1, and the influence of uneven rotation of the drum 2 is exerted on all the recording means 8. Therefore, it is possible to prevent occurrence of recording position deviation between the recording means 8.

  Further, all the recording lights from the respective recording means 8 are directed in the same direction. By doing so, the incident angles of the recording light to the recording medium 1 are substantially equal for all the recording means 8, and therefore it is possible to reduce the recording position deviation between the recording means 8. Furthermore, since the function for correcting the exposure start timing of each recording means 8 depends on the incident angle θ of the recording light to the recording medium 1, all of these functions can be made the same with a simple setting. The exposure start timing can be corrected.

  Consider the case where the recording medium holding means is the drum 2. In this case, since the recording medium 1 is always in close contact with the surface of the drum 2, the variation in the distance between the recording means 8 and the recording medium 1 is reproduced for each rotation of the drum 2. Therefore, if the data of the detection result from the distance detection means 16 is only for one revolution of the drum 2, it can be applied to every revolution of the drum 2. Therefore, the distance detection means 16 detects the distance information for only one revolution of the drum 2, stores the detected data in a storage unit (not shown), and based on the data in the storage unit, the recording means 8 The exposure start timing can be corrected for each rotation of the drum 2.

  FIG. 13 is a flowchart for explaining adjustment of the exposure start timing at that time. When the distance signal is input from the distance detection means 16 during the first rotation of the drum 2 (step S11), the exposure start timing correction amount δ is calculated based on the distance signal (step S12), and the correction is performed. The exposure start timing is adjusted according to the amount (step S13). The input distance signal is stored in the storage unit (step S14). When the rotation of the drum 2 reaches the second turn, the driving of the distance detection unit 16 is stopped (step S15), and the correction amount of the exposure start timing is calculated based on the distance signal called from the storage unit (step S16). The exposure start timing is adjusted according to the correction amount (step S17).

By performing such processing, the driving time of the distance detecting means 16 can be reduced, and simplification of signal processing and energy saving can be realized. More specifically, the distance between the recording means and the recording medium during one rotation of the drum is detected, the detection result is stored in the storage unit, and the distance is not detected during subsequent rotations of the drum. The exposure start timing is adjusted according to the recorded detection result. Thereby, the recording position shift caused by the eccentricity of the drum is prevented. In addition, the operation time of the distance detecting means is shortened, and signal processing is simplified and energy is saved.

  A third embodiment of the present invention will be described with reference to FIGS. In the recording apparatus P3 of the present embodiment, a plurality of recording means 8 are arranged in two rows in parallel with the axial direction of the drum 2, and the recording means 8 are arranged in a staggered manner. By doing so, the recording width scanned by one recording means 8 may be half of the width of the recording means 8 itself, so that further high-speed recording on the wide recording medium 1 becomes possible. Needless to say, if the number of rows is increased to 3 rows and 4 rows, higher speed recording and higher image quality recording are possible.

  In this case, in the same row of the recording means 8, all the recording lights from the recording means 8 are directed in the same direction. By doing so, since the incident angles of the recording light to the recording medium 1 are substantially equal for all the recording means 8 in the same row of the recording means 8, it is possible to reduce the recording position deviation between the recording means 8. It becomes. Further, since the function for correcting the exposure start timing of each recording means 8 depends on the incident angle of the recording light to the recording medium 1, all the functions are made the same in the recording means 8 in the same column. This makes it possible to correct the exposure start timing with simple settings.

  As a matter of course, since the incident angle and the incident direction of the recording light from the recording unit 8 on the recording medium 1 are different in different columns of the recording unit 8, the exposure start timing is corrected in the different columns of the recording unit 8. The function to do is different.

  At this time, the recording positions on the drum 2 of the recording means 8 arranged in a plurality of rows are arranged in a row in the axial center direction of the drum 2 (direction orthogonal to the traveling direction of the recording medium 1). If it is not a single row, a recording position shift between different rows of the recording means 8 may occur due to the influence of uneven rotation of the drum 2 or the like. FIG. 17 shows a state where a recording position shift occurs between different columns of the recording means 8. A is an area recorded by the recording means 8 in the upper row, and B is an area recorded by the recording means 8 in the lower row. If this is in one line, the influence of the rotation unevenness of the drum 2 acts on all the recording means 8 in the same manner, so that it is possible to prevent the occurrence of recording position deviation between the recording means 8 in different rows. become.

1 is a plan view showing a recording apparatus according to a first embodiment of the present invention. It is the side view. FIG. 3 is an explanatory diagram of color development / decoloration phenomenon of a rewritable recording medium. It is a side view which shows the other example of a paper feeder. It is a top view which shows the detail of a recording means. FIG. 6 is a side view for explaining a recording position shift caused by the eccentricity of a drum or the floating of a recording medium. It is a side view which shows arrangement | positioning of a distance detection means and a recording means. It is a block diagram which shows the outline of the circuit structure for preventing a recording position shift. It is a flowchart explaining adjustment of exposure start timing. It is explanatory drawing about the function which prescribes | regulates an exposure start timing. It is a top view which shows the recording device of the 2nd Embodiment of this invention. FIG. It is a flowchart explaining adjustment of exposure start timing. It is a top view which shows the recording device of the 3rd Embodiment of this invention. It is the side view. It is a front view which shows the staggered arrangement | sequence state of a recording means. It is a top view which shows the mode of the recording position shift which may generate | occur | produce when a recording position is not one line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording medium 2 Recording medium holding means, drum 5 Light source 6 Lens 7 Board | substrate 8 Recording means 16 Distance detection means 17 Adjustment means 18 Storage part

Claims (11)

A rotatable cylindrical drum holding a recording medium on which recording is performed by light exposure;
A light source and a lens, arranged along the width direction of the recording medium perpendicular to the traveling direction of the recording medium traveling while being held by the drum , and inclined with respect to the normal direction of the peripheral surface of the recording medium A plurality of recording means for exposing light onto the recording medium from a predetermined position;
A distance detection unit that is provided for each of the recording units and detects a distance between the recording unit and the recording medium held by the drum during one rotation of the drum ;
Adjusting means for adjusting the exposure start timing by the recording means according to the detection result of the distance detecting means;
Equipped with,
The distance detecting means stores a detection result obtained by detecting a distance between the recording means and the recording medium during the first rotation of the drum in a storage unit, and is driven during the second and subsequent rotations of the drum. Is stopped,
The adjusting unit adjusts the exposure start timing by the recording unit according to the detection result stored in the storage unit during the second and subsequent rotations of the drum.
A recording apparatus. The recording apparatus according to claim 1, further comprising a storage unit that stores a function defining a relationship between a detection result of the distance detection unit and an adjusted exposure start timing . It said distance detecting means, the recording means and the same recording apparatus according to claim 1, wherein is provided on the substrate. The recording apparatus according to claim 1 , wherein the distance detection unit is disposed in a non-contact manner with respect to a recording medium held on the drum . 5. The plurality of recording units are arranged in a line in a direction parallel to the surface of the recording medium held on the drum and perpendicular to the traveling direction of the recording medium . Recording device. The recording apparatus according to claim 5 , wherein the light from the recording unit is incident on the recording medium held on the drum from the same direction . 7. A recording apparatus according to claim 5 , wherein the function defining the relationship between the detection result from the distance detection means and the adjusted exposure start timing is the same for all the recording means . The recording means of the double number of of claims 1 are staggered in two or more rows which is parallel to the direction perpendicular to the traveling direction of the recording medium on the surface of the recording medium held on the drum 4 The recording device according to any one of the above. The recording apparatus according to claim 8 , wherein the light from the recording means in the same row is incident on the recording medium held on the drum from the same direction . Recording position on the recording medium held on the drum by a plurality of said recording means which are staggered in two or more rows, the recording claim progression are arranged in a row in a direction perpendicular to the direction of the medium 8 or 9 The recording device described. 11. The recording apparatus according to claim 8 , wherein a function defining a relationship between a detection result from the distance detection unit and an adjusted exposure start timing is the same in the recording unit in the same column .

Images