JP2008143002A - Non-contact optical writing device - Google Patents

Abstract

An object of the present invention is to improve the quality of recording without erasing a part of the recording of a line already recorded at low cost.
A light shielding member is provided downstream of a main scanning position Q of a semiconductor laser beam R output from a laser light source 1 such as a semiconductor laser in a conveyance direction of a thermal recording medium 3, and from a current main scanning position Q. In addition, the semiconductor laser beam R is shielded from light in the region g at least at the intermediate temperature downstream in the transport direction b of the thermal recording medium 3.
[Selection] Figure 2

Description

  The present invention relates to a non-contact optical writing apparatus that performs non-contact information recording on a rewritable thermosensitive recording medium that enables non-contact thermal recording and thermal erasure without directly contacting a heating device such as a thermal head. About.

  There are heat-sensitive recording media such as a heat-sensitive recording method using a leuco dye-based or diazo compound-based heat-sensitive material, and a reversible heat-sensitive recording paper that can repeat color development and decoloring at a specific temperature. The heat-sensitive recording paper is heated and developed using a heating device such as a line-shaped thermal head in which a plurality of heating element elements are arranged. As a recording method for such a thermal recording paper, a method in which a recording head such as a thermal head is brought into direct contact is the mainstream.

As an information recording technique using such heat-sensitive recording paper, there is, for example, Patent Document 1. This patent document 1 relates to an initialization method, a rewriting method, and an apparatus for obtaining a good recorded image having no afterimage (color unevenness) when rewriting an image on a reversible thermosensitive recording medium. Disclosed is an operation for uniformizing the recording layer by heating the entire surface or recording area of the reversible thermosensitive recording medium, which develops or decolors depending on the speed, to a coloring temperature by a thermal head to develop a color.
In such a recording method using a thermal head, there is a risk of damaging the protective layer of the thermal recording paper in order to bring the thermal head into contact with the thermal recording paper. For this reason, the number of retries for recording information on the thermal recording paper may not reach the number of retries originally expected.

  Under such circumstances, a method for recording information in a non-contact manner on a thermal recording medium using a laser light source has been proposed. As a recording method using a laser light source, for example, there are the following two methods. FIG. 6 shows the first recording method. This first recording method is used in, for example, a laser printer. A semiconductor laser beam R output from a laser light source 1 such as a semiconductor laser is irradiated onto the polygon mirror 2, and the semiconductor laser beam R is scanned in the main scanning direction a of the thermal recording medium 3 by the rotation of the polygon mirror 2. At this time, since the thermal recording medium 3 is conveyed in the sub-scanning direction b, information is recorded on the two-dimensional surface of the recording surface of the thermal recording medium 3.

  FIG. 7 shows a second recording method. In this second recording method, a line light source 4 in which laser light sources such as a plurality of semiconductor lasers are arranged in a line is arranged along the main scanning direction a above the thermal recording medium 3 and output from the line light source 4. A plurality of semiconductor laser beams are irradiated onto the recording surface of the thermal recording medium 3. At this time, since the thermal recording medium 3 is conveyed in the sub-scanning direction b, information is recorded on the two-dimensional surface of the recording surface of the thermal recording medium 3.

The reversible thermosensitive recording medium 3 is a rewritable and reversible medium that repeats color development and decoloring by heating control at a specific temperature to enable thermal recording and thermal erasure. FIG. 8 shows the coloring and erasing characteristics of the thermal recording medium 3. For example, when the melting point of 180 ° C. or higher is applied, the heat-sensitive recording medium 3 is in a state where the dye and developer present in the print layer are melted, and the dye and developer are mixed by rapid cooling from this state. Crystallizes as it is and develops color. On the other hand, when the thermal recording medium 3 is slowly cooled, the dye and the developer are crystallized, so that the colored state cannot be maintained and the erased state is obtained. Further, the heat-sensitive recording medium 3 is a temperature range in which the dye and the developer are gradually separated and crystallized by heating for a certain time which is not more than the melting point of the dye and the developer, for example, about 130 ° C. There is also about -170 degreeC. As described above, the thermal recording medium 3 performs printing and erasing by strictly controlling the temperature and time.
JP 2001-341429 A

However, when the semiconductor laser beam R is scanned in the main scanning direction a of the thermal recording medium 3 by the polygon mirror 2 or the like as in the first recording method, the recording surface of the thermal recording medium 3 is, for example, as shown in FIG. By recording the current line, a part of the previously recorded previous line is deleted. That is, on the thermal recording medium 3, for example, the semiconductor laser beam R is scanned in the main scanning direction “a”, and a plurality of lines Ln are recorded by conveying the thermal recording medium 3 in the sub-scanning direction “b”. For example, after the first line L ₁ recording is performed, 2 when recording the line L _2, the erase area will already erased a part of a recording of the recorded previous line is the first line L ₁ e ₁ is produced. Similarly, after the second line L ₂ recording is performed, 3 when the recording of line L _3, will already erased part of recorded before the line is a second line L ₂ recorded erase area _{e 2} occurs.

The erasing areas e _{1 to} en ₁ are thus generated because the profile of the semiconductor laser beam R output from the laser light source 1 such as a semiconductor laser forms a Gaussian distribution as shown in FIG. It is. For example, the light emission central portion of the laser light source 1 has a large amount of light and can easily heat the thermal recording medium 3. On the other hand, the light emitting end of the laser light source 1 has a small amount of light and is difficult to heat the thermal recording medium 3. When recording is performed by scanning the semiconductor laser beam R output from the laser light source 1 on the thermal recording medium 3, normal recording is performed by the central portion of the Gaussian distribution in the semiconductor laser beam R during the recording of the first line L _1. Record is obtained.

However, when the second line L ₂ recording, the first line L ₁ recording is already in the colored state, that is, the recording completion. Therefore, when the second line L ₂ recorded as shown in FIG. 11, the end portion of the Gaussian distribution is irradiated to a portion of one of the line L ₁ recording of the semiconductor laser beam R, already colored state i.e. in a recording completion a part of a first line L ₁ recording the erased state, thereby erasing the recorded. Similarly, when in the third line L ₃ and subsequent recording, thereby erasing the part of the previous line L ₂ records.
On the other hand, since the second recording method uses the line light source 4 in which a plurality of laser light sources are arranged in a line, the cost becomes high.

  An object of the present invention is to provide an inexpensive non-contact optical writing apparatus capable of improving the quality of recording without erasing a part of the recording of the already recorded line.

  The present invention transports at least a rewritable thermal recording medium enabling thermal recording, and scans a laser beam in a direction perpendicular to the transport direction on the thermal recording medium to record information on the thermal recording medium. In the optical writing device, provided at the downstream side of the scanning direction of the laser beam in the transport direction, of the irradiation region of the laser beam scanned on the thermal recording medium, the region where the thermal recording medium is in an erased state is irradiated. This is a non-contact optical writing device including a light blocking member that blocks a part of a laser beam.

  According to the present invention, it is possible to provide an inexpensive non-contact optical writing apparatus capable of improving the quality of recording without erasing a part of the recording of the already recorded line.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 1 shows a configuration diagram of a non-contact optical writing apparatus. A light shielding member 10 is provided above the recording surface of the thermal recording medium 3. The light shielding member 10 is provided downstream of the main scanning position of the semiconductor laser beam R output from the laser light source 1 such as a semiconductor laser in the transport direction of the thermal recording medium 3. The light shielding member 10 is disposed at a height position slightly above the recording surface of the thermal recording medium 3. The height interval between the light shielding member 10 and the recording surface of the thermal recording medium 3 is such that the semiconductor laser beam R is diffracted when the main scan is performed and does not enter the gap between the light shielding member 10 and the recording surface of the thermal recording medium 3. Set to degree. The light shielding member 10 is formed in a plate shape having a linear edge 11 along the main scanning direction a of the semiconductor laser beam R.

  As shown in FIG. 2, the light-shielding member 10 is irradiated on the recording surface of the thermal recording medium 3 to an area where the thermal recording medium 3 is at least erased, among the irradiation areas of the semiconductor laser beam R that is currently main scanned. A part of the semiconductor laser beam is shielded from light. That is, the semiconductor laser beam R has a laser power with a Gaussian distribution. Thus, when the semiconductor laser beam R is irradiated onto the recording surface of the thermal recording medium 3, the laser power is greatly developed on the recording surface of the thermal recording medium 3 at the center of the semiconductor laser beam R as shown in FIG. A region f having a high temperature (for example, a melting point of 180 ° C.), a region g having a medium temperature (for example, about 130 ° C. to 170 ° C.) in the erased state in the outer ring of the region f, and an outer ring of the region g As a result, a region h having a medium temperature or less without change is generated on the recording surface of the thermal recording medium 3. Note that FIG. 2 shows a region f where the color development state becomes high temperature by irradiation with the semiconductor laser beam R by a solid line, and a region g where the erased state becomes medium temperature is shown by a dotted line.

  Therefore, the light shielding member 10 applies a part of the semiconductor laser beam R at the current main scan position Q of the semiconductor laser beam R, i.e., the semiconductor laser beam R in the region g in the erased state of the semiconductor laser beam R. Shield from light. That is, the light-shielding member 10 has the semiconductor laser beam R in the region g that is at the intermediate temperature downstream in the transport direction b of the thermal recording medium 3 from the current main scan position Q of the semiconductor laser beam R, that is, the thermal recording medium 3. The semiconductor laser beam R on the area E side already recorded on the recording surface is shielded. Actually, the light shielding member 10 shields the semiconductor laser beam R in the region g where the temperature is intermediate and the region h where the temperature is lower than the intermediate temperature.

Next, a recording operation by the apparatus configured as described above will be described.
A laser light source 1 such as a semiconductor laser outputs a semiconductor laser beam R. This semiconductor laser beam R is applied to the polygon mirror 2. The polygon mirror 2 rotates and scans the semiconductor laser beam R in the main scanning direction a of the thermal recording medium 3. Since the thermal recording medium 3 is transported in the sub-scanning direction b at a constant transport speed, for example, information is recorded on the two-dimensional surface of the recording surface of the thermal recording medium 3.

  Here, when the semiconductor laser beam R is scanned in the main scanning direction a of the thermal recording medium 3, the light shielding member 10 is downstream of the main scanning position of the semiconductor laser beam R in the transport direction of the thermal recording medium 3, that is, thermal sensitivity. It is provided on the recording surface of the recording medium 3 on the side of the area E that has already been recorded. Specifically, the linear edge portion 11 of the light shielding member 10 is located downstream of the current main scan position Q in the transport direction b of the thermal recording medium 3 and has a high color temperature (for example, a melting point of 180 ° C.). It is arranged on the boundary between the region f that becomes and the region g that becomes an intermediate temperature (for example, about 130 ° C. to 170 ° C.). As a result, the light shielding member 10 is already on the recording surface of the semiconductor laser beam R in the region g where the intermediate temperature is lower than the current main scan position Q in the conveyance direction b of the thermal recording medium 3, that is, the recording surface of the thermal recording medium 3. The semiconductor laser beam R on the recorded region E side is shielded. Actually, the light shielding member 10 shields the semiconductor laser beam R in the region g where the temperature is intermediate and the region h where the temperature is lower than the intermediate temperature. A region g that is an intermediate temperature on the downstream side in the transport direction b of the thermal recording medium 3 and an area h that is equal to or lower than the intermediate temperature are regions E that have already been recorded on the recording surface of the thermal recording medium 3.

  At this time, since the light shielding member 10 is disposed at a height position slightly above the recording surface of the thermal recording medium 3, the semiconductor laser beam R during main scanning is diffracted and the light shielding member 10 and the thermal recording medium 3 are diffracted. Does not enter the gap between the recording surface of

  However, the region E that has already been recorded on the recording surface of the thermal recording medium 3 is not irradiated with the semiconductor laser beam R in the region g of the semiconductor laser beam R that has an intermediate temperature in the erased state, and has already been recorded. A part of the line record is not erased.

  As described above, according to the first embodiment, the light shielding member 10 is located downstream of the main scanning position Q of the semiconductor laser beam R output from the laser light source 1 such as a semiconductor laser in the transport direction of the thermal recording medium 3. , And shields the semiconductor laser beam R in the region g at least at the intermediate temperature downstream in the transport direction b of the thermal recording medium 3 from the current main scan position Q. As a result, the region E that has already been recorded on the recording surface of the thermal recording medium 3 is irradiated with the semiconductor laser beam R in the region g of the semiconductor laser beam R that is at an intermediate temperature (for example, about 130 ° C. to 170 ° C.). This eliminates the possibility that a part of the recording of the already recorded line is erased, thereby improving the recording quality. In addition, since only the plate-shaped light shielding member 10 is provided, the cost is low.

Next, a second embodiment of the present invention will be described with reference to the drawings. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 4 shows a configuration diagram of the non-contact optical writing apparatus. A laser sensor 20 is provided at one end of the linear edge 11 of the light shielding member 10. The laser sensor 20 detects the semiconductor laser beam R that is main-scanned by the polygon mirror 2 and outputs a laser detection signal corresponding to the amount of light received by the semiconductor laser beam R. Needless to say, the polygon mirror 2 performs main scanning with the semiconductor laser beam R up to the position where the laser sensor 20 is disposed.

The sensor output monitor 21 receives the laser detection signal output from the laser sensor 20, and monitors and outputs the amount of light received by the semiconductor laser beam R received by the laser sensor 20.
The mask sheet position adjusting mechanism 22 moves the light shielding member 10 upstream and downstream in the conveyance direction of the thermal recording medium 3 in the direction of arrow c along the conveyance speed of the thermal recording medium 3, that is, the sub-scanning direction b of the semiconductor laser beam R. It is possible to move in each direction with the side D. The mask sheet position adjusting mechanism 22 moves the light shielding member 10 by driving a driving unit 23 such as a motor.

  The position control unit 24 receives the received light amount of the semiconductor laser beam R received by the laser sensor 20 from the sensor output monitor 21, determines whether or not the received light amount is within a preset reference received light amount, If it is within the amount of received light, the current position of the light shielding member 10 is maintained. Here, the reference amount of light received is the semiconductor laser beam R corresponding to the region g where the temperature when the semiconductor laser beam R is irradiated onto the recording surface of the thermal recording medium 3 becomes an intermediate temperature and the region h where the temperature is less than the intermediate temperature. Is the amount of light received. Accordingly, when the light shielding member 10 is shifted to the upstream side U in the conveyance direction of the thermal recording medium 3, the laser sensor 20 receives the region f of the semiconductor laser beam R that is in a high color development state. Exceeds the reference received light amount. On the other hand, when the light shielding member 10 is shifted to the downstream side D in the conveyance direction of the thermal recording medium 3, the laser sensor 20 receives a large amount of the region h below the intermediate temperature in the semiconductor laser beam R. Below received light level.

  However, if the received light amount of the semiconductor laser beam R received by the laser sensor 20 exceeds the reference received light amount, the position control unit 24 is shifted to the upstream U in the transport direction of the thermal recording medium 3. Then, a control signal for moving the light shielding member 10 to the downstream side D in the conveyance direction of the thermal recording medium 3 is sent to the drive unit 23. Further, the position control unit 24 detects that the light shielding member 10 is shifted to the downstream side D in the conveyance direction of the thermal recording medium 3 when the light reception amount of the semiconductor laser beam R received by the laser sensor 20 falls below the reference light reception amount. Then, a control signal for moving the light shielding member 10 to the upstream side U in the conveyance direction of the thermal recording medium 3 is sent to the drive unit 23.

Next, a recording operation by the apparatus configured as described above will be described.
As in the first embodiment, the semiconductor laser beam R output from the laser light source 1 such as a semiconductor laser is scanned in the main scanning direction a of the thermal recording medium 3 by the polygon mirror 2 and is also scanned by the light shielding member 10. The semiconductor laser beam R on the area E side that has already been recorded on the recording surface of the thermal recording medium 3 is shielded and irradiated onto the recording surface of the thermal recording medium 3, and information is recorded on the two-dimensional surface of the recording surface of the thermal recording medium 3. Is recorded.

  At this time, the laser sensor 20 detects the semiconductor laser beam R main-scanned by the polygon mirror 2 and outputs a laser detection signal corresponding to the amount of light received by the semiconductor laser beam R. The sensor output monitor 21 receives the laser detection signal output from the laser sensor 20, and monitors and outputs the amount of light received by the semiconductor laser beam R received by the laser sensor 20.

  The position control unit 24 receives the received light amount of the semiconductor laser beam R received by the laser sensor 20 from the sensor output monitor 21, and determines whether or not this received light amount is within a preset reference received light amount. If the result of this determination is that it is within the reference amount of received light, the position control unit 24 maintains the current position of the light shielding member 10.

  On the other hand, if the received light amount of the semiconductor laser beam R received by the laser sensor 20 exceeds the reference received light amount, the light shielding member 10 is shifted to the upstream U in the transport direction. A control signal for moving the thermal recording medium 3 to the downstream side D in the transport direction is sent to the drive unit 23. Thereby, the light shielding member 10 is moved by the mask sheet position adjusting mechanism 22 to the downstream side D in the conveyance direction of the thermal recording medium 3 in the arrow c direction. The received light amount of the semiconductor laser beam R received by the laser sensor 20 by the movement of the light shielding member 10 falls within the reference received light amount. Then, the received light amount of the semiconductor laser beam R received by the laser sensor 20 falls within a preset reference received light amount, and the position control unit 24 maintains the position of the light shielding member 10.

  If the amount of light received by the semiconductor laser beam R received by the laser sensor 20 is less than the reference amount of light received, the light shielding member 10 is shifted to the downstream side D in the transport direction of the thermal recording medium 3, so that the position controller 24 is Then, a control signal for moving the light shielding member 10 to the upstream side U in the transport direction is sent to the drive unit 23. Thereby, the light shielding member 10 is moved by the mask sheet position adjusting mechanism 22 to the upstream U in the conveyance direction of the thermal recording medium 3 in the arrow c. The received light amount of the semiconductor laser beam R received by the laser sensor 20 by the movement of the light shielding member 10 falls within the reference received light amount. Then, the received light amount of the semiconductor laser beam R received by the laser sensor 20 falls within a preset reference received light amount, and the position control unit 24 maintains the position of the light shielding member 10.

  As a result, the position of the light shielding member 10 is controlled to a position where the received light amount of the semiconductor laser beam R received by the laser sensor 20 from the sensor output monitor 21 is within a preset reference received light amount. However, the region E that has already been recorded on the recording surface of the thermal recording medium 3 is not irradiated with the semiconductor laser beam R in the region g of the semiconductor laser beam R that has an intermediate temperature in the erased state, and has already been recorded. A part of the line record is not erased.

  As described above, according to the second embodiment, the laser sensor 20 is provided at one end of the linear edge portion 11 of the light shielding member 10 and the semiconductor laser beam R received by the laser sensor 20 is received. The light shielding member 10 is controlled to move to the upstream U or downstream D in the transport direction of the thermal recording medium 3 according to the amount. As a result, the light shielding member 10 is not displaced to the upstream U or downstream D in the transport direction of the thermal recording medium 3, and the thermal recording is performed without erasing a part of the recorded line. The reliability of information recording on the two-dimensional surface of the recording surface of the recording medium 3 can be improved.

  Further, the laser sensor 20, the sensor output monitor 21, the mask sheet position adjusting mechanism 22, the drive unit 23, and the position control unit 24 can be integrated to separately constitute a position adjusting device for the light shielding member. Such a light-shielding member position adjusting device is used, for example, in the manufacturing process of the present device, and the position g of the light-shielding member 10 is at least the intermediate temperature downstream of the current main scan position Q in the transport direction b of the thermal recording medium 3. The semiconductor laser beam R can be adjusted and fixed at a light shielding position, and then the apparatus can be shipped.

Moreover, it is also possible to incorporate such a light-shielding member position adjusting device into this device, for example. If incorporated in this apparatus, for example, the position of the light shielding member 10 is periodically shielded from the semiconductor laser beam R in the region g at least at the intermediate temperature downstream of the current main scan position Q in the transport direction b of the thermal recording medium 3. It can be adjusted to the position.
Furthermore, the laser power of the semiconductor laser beam R output from the laser light source 1 such as a semiconductor laser decreases with time, and the Gaussian distribution changes accordingly. The size of the region g and the region h below the intermediate temperature changes. Even if the region g that reaches the intermediate temperature changes as described above, the semiconductor laser in the region g that reaches at least the intermediate temperature downstream of the current main scan position Q in the transport direction b from the current main scan position Q according to the change. The light shielding member 10 can be adjusted to a position where the beam R is shielded.
The adjustment of the position of the light shielding member 10 is not limited to being performed automatically using the mask sheet position adjusting mechanism 22, and may be performed manually by an operator using a micrometer, for example.

Next, a third embodiment of the present invention will be described with reference to the drawings. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 5 shows a configuration diagram of the non-contact optical writing apparatus. The transport speed sensor 30 is provided in the transport mechanism, detects the transport speed of the thermal recording medium 3 in the sub-scan direction b, and outputs a transport speed detection signal.
The tilt mechanism 31 varies the tilt angle α with respect to the scanning direction a of the light shielding member 10.
The tilt angle control unit 32 receives the transport speed detection signal output from the transport speed sensor 30 and controls the tilt angle α of the light shielding member 10 with respect to the scanning direction a by the tilt mechanism 31 according to the transport speed of the thermal recording medium 3. The control signal to be sent is sent to the tilt mechanism 31. That is, when the conveyance speed of the thermal recording medium 3 in the sub-scanning direction b is increased, when the semiconductor laser beam R is scanned in the main scanning direction a, the semiconductor to be main scanned on the recording surface of the actual thermal recording medium 3. The locus of the laser beam R has an inclination angle α corresponding to the conveyance speed of the thermal recording medium 3 with respect to the main scanning direction a.

  With such a configuration, as in the first embodiment, the semiconductor laser beam R output from the laser light source 1 such as a semiconductor laser is scanned in the main scanning direction a of the thermal recording medium 3 to perform thermal recording. While recording information on the recording surface of the medium 3, the transport speed sensor 30 is provided in the transport mechanism, detects the transport speed of the thermal recording medium 3 in the sub-scan direction b, and outputs a transport speed detection signal. The tilt angle control unit 32 receives the transport speed detection signal output from the transport speed sensor 30 and receives a control signal for controlling the tilt angle α of the light shielding member 10 with respect to the scanning direction a according to the transport speed of the thermal recording medium 3. It is sent to the tilt mechanism 31. The tilt mechanism 31 receives a control signal from the tilt angle control unit 32 and varies the tilt angle α of the light shielding member 10 with respect to the scanning direction a. The inclination angle α is largely controlled as the conveyance speed of the thermal recording medium 3 increases.

  As described above, according to the third embodiment, since the inclination angle α of the light shielding member 10 with respect to the scanning direction a is controlled in accordance with the conveyance speed of the thermal recording medium 3, the conveyance speed of the thermal recording medium 3 is increased. Even if the locus of the semiconductor laser beam R to be main scanned on the recording surface of the actual thermosensitive recording medium 3 has an inclination angle α with respect to the main scanning direction a, the light shielding member 10 is scanned according to the inclination angle α. The inclination angle α with respect to the direction a can be controlled, and the reliability of information recording on the two-dimensional surface of the recording surface of the thermal recording medium 3 is improved without erasing a part of the recording of the already recorded line. it can.

  In the present embodiment, the inclination angle α of the light shielding member 10 with respect to the scanning direction a is controlled according to the conveyance speed of the thermal recording medium 3. However, if the conveyance speed of the thermal recording medium 3 is set to be constant in advance. The light shielding member 10 may be fixedly arranged at an inclination angle α corresponding to the transport speed. In this case, the conveyance speed sensor 30, the tilt mechanism 31, and the tilt angle control unit 32 need not be provided.

Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.
The laser sensor 20 is provided at one end of the linear edge 11 in the light shielding member 10, but is not limited thereto, and may be provided at both ends of the linear edge 11. When the respective laser sensors 20 are provided at both ends of the linear edge portion 11, the position of the light shielding member 10 is set so that the received light amounts detected by the laser sensors 20 are both within a preset reference received light amount. To control.

  Further, the second embodiment shown in FIG. 4 and the third embodiment shown in FIG. 5 are combined, and the light shielding member 10 is subjected to thermal recording in accordance with the amount of light received by the semiconductor laser beam R received by the laser sensor 20. The movement angle of the light shielding member 10 with respect to the scanning direction a may be controlled according to the conveyance speed of the thermal recording medium 3 by controlling the movement to the upstream U or downstream D in the conveyance direction of the medium 3.

The block diagram which shows 1st Embodiment of the non-contact optical writing apparatus which concerns on this invention. The schematic diagram which shows the semiconductor laser beam light-shielded by the light-shielding member in the same apparatus. The figure which shows the area | region which shields the semiconductor laser beam in the same apparatus. The block diagram which shows 2nd Embodiment of the non-contact optical writing apparatus which concerns on this invention. The block diagram which shows 3rd Embodiment of the non-contact optical writing apparatus which concerns on this invention. The figure which shows the 1st recording method to the thermosensitive recording medium using the conventional laser light source. The figure which shows the 2nd recording method to the thermosensitive recording medium using the conventional laser light source. The figure which shows the recording / erasing characteristic of a thermosensitive recording medium. The figure which shows the erasure | elimination area which arises in a thermosensitive recording medium conventionally. The figure which shows the Gaussian distribution of a semiconductor laser beam. The figure which shows the relationship between the Gaussian distribution in the laser beam by the scan of each line, and the part of an erased state.

Explanation of symbols

  1: Laser light source such as semiconductor laser, 2: Polygon mirror, 3: Thermal recording medium, 10: Light shielding member, 11: Linear edge, 20: Laser sensor, 21: Sensor output monitor, 22: Mask sheet position adjustment Mechanism: 23: driving unit, 24: position control unit, 30: transport speed sensor, 31: tilting mechanism, 32: tilting angle control unit.

Claims (8)

Non-contact light that transports at least a rewritable thermal recording medium that enables thermal recording and records information on the thermal recording medium by scanning a laser beam in a direction perpendicular to the transport direction on the thermal recording medium In the writing device,
The laser beam is provided on the downstream side of the scanning direction with respect to the scanning position of the laser beam, and at least the region where the thermal recording medium is erased is irradiated among the irradiation regions of the laser beam scanned on the thermal recording medium. A non-contact optical writing apparatus comprising a light shielding member for shielding a part of the laser beam.   The non-contact optical writing apparatus according to claim 1, wherein the light shielding member is disposed slightly above the thermal recording medium.   2. The non-contact optical writing apparatus according to claim 1, wherein the light shielding member is formed in a plate shape having a linear edge along the scanning direction of the laser beam.   2. The light shielding member shields the part of the laser beam having a laser power at which the temperature when irradiated to the thermal recording medium is an erasing temperature and a temperature equal to or lower than the erasing temperature. The non-contact optical writing device described.   The non-contact optical writing apparatus according to claim 1, wherein the light shielding member is provided to be inclined with respect to the scanning direction of the laser beam according to a conveyance speed of the thermal recording medium. At least one laser sensor provided on the light shielding member and detecting the scanned laser beam;
A position adjusting mechanism for moving the light shielding member in the transport direction;
A part of the laser beam irradiated to an area where the thermal recording medium is erased by controlling the movement of the light shielding member in the transport direction by the position adjusting mechanism based on a detection signal output from the laser sensor A position control unit for adjusting the light shielding member to a position for shielding light;
The non-contact optical writing apparatus according to claim 1, comprising: The light shielding member is formed in a plate shape having a linear edge along the scanning direction of the laser beam,
The non-contact optical writing device according to claim 6, wherein the laser sensor is provided at one or both ends of the linear edge of the light shielding member. An inclination mechanism for inclining the light shielding member with respect to the scanning direction;
A conveyance speed sensor for detecting a conveyance speed of the thermal recording medium;
An inclination angle control unit that controls an inclination angle of the light shielding member by the inclination mechanism with respect to the scan direction in accordance with the conveyance speed detected by the conveyance speed sensor;
The non-contact optical writing apparatus according to claim 1, comprising:

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