JP2003118884A - Method and device for aligning sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To align sheets to obtain an proper image. SOLUTION: The device is comprised of a first and second support stoppers for supporting sheets against gravity at a first non-alignment position. The device has another two alignment stoppers and a means for moving sheets from the first non-alignment position to the second alignment position. At the second alignment position, the linear edge of sheets abuts the two alignment stoppers and the first support stopper supports sheets while the second support stopper does not support sheets.

Description

Detailed Description of the Invention

[Field of Industrial Application] The present invention relates to a sheet (sh
and a device for aligning eets). In particular, the present invention is a thermal printer.
r-) thermal-sensitive sheet
s) a method and device for matching.

[0002]

BACKGROUND OF THE INVENTION Thermal imaging or thermography is a recording process in which an image is generated by the use of thermal energy.

Thermography has three measures (approa
ches) are known.

1. Direct thermal formation of a visible image pattern by image-wise heating of a recording material containing substances that alter color or optical density by chemical or physical processes.

2. An image-wise transfer of an ingredient necessary for a chemical or physical process that results in a change in color or optical density change,
Receptor element containing another component required for the chemical or physical process followed by uniform heating that results in the change in color or optical density.
The image type transfer to t) is performed.

3. Imagewise heated donor element (done
r element) to receptor element (receptor element)
Thermal dye transfer printing (Thermal transfer) in which the visible image pattern is formed by the transfer of the colorized type onto
dye transfer printing).

One type of thermographic material can be made photothermographic by incorporating a photosensitive agent, which is sensitive to light in the ultraviolet, visible or infrared range. , It can catalyzing or participating in thermographic processes that result in a change in color or optical density after exposure, for example by a laser.

A survey of direct thermal imaging methods has been published by The Focal Press-London and New York (The
Focal Press-London and New York) (1976
Year), Court eye. Jacobson-Ralphey. V. of the book "Imaging systems" by Kurt I. Jacobson-Ralph E. Jacobson
In Chapter II, "7.1 Thermographic (7.1 Thermogr
aphy) ”.

A conventional thermal printer that does not use a laser light source has a rotatable drum and a long thermal head that is spring biased toward the drum to ensure line contact with the thermal material. The heat sensitive material is passed between the head and the drum. The thermal head has a plurality of heating elements. The imagewise heating of the sheet is done on a line by line basis, the heating elements in a bead-like row running parallel to the axis of the drum. ) Geometrically placed along each other. Each of these elements can be energized by a heating pulse, the energy of the pulse being controlled according to the required density of the corresponding picture element. The sheet is advanced between the head and the drum by frictional contact with the drum behind it.

Patent application EP-A-0846565 discloses such a printer having a thermal head.

Images printed on such thermal printers are often used for diagnostic purposes, especially for medical diagnosis. Customarily such images for medical diagnosis are printed on a transparent support. Examples of such images are ecograms, sheet scans (CT sc
ans), and NMR images. These images are negative-type images, which means that their background is substantially black, meaning that the details of the image have less optical density. FIG. 1 shows two sheets 10 bearing an image printed by a thermal printer having a thermal head. The image range E is substantially black, and the margins A, B, C
And D is transparent. The image cannot be printed on the sheet up to the edge, otherwise the thermal sensitive layer of the sheet will clamp at the edge due to the pressure between the head and the drum. Squeezed because it stains the thermal head and the transport rollers.

These images are viewed on a light box for diagnostic purposes. On the light box, the image is such that the transparent margin B is outside the illumination range, while a black screen can be moved within the light box just like a curtain so that they are aligned with the margin C. Positioned to cover D. However, if the two sheets 10 are positioned alongside one another, as shown in FIG. 1, then a transparent area between the two image areas E remains.

Fluorographers are unfamiliar with such transparent areas that do not exist in conventional AgX X-ray images. Furthermore, a large transparent area has the effect of making it dazzling. FIG. 1 shows mammographic images. Mammography
aphy), it is customary to see on the lightbox images of the right and left breasts positioned relative to each other, as shown in FIG. 1 (reference numeral 15 in FIG. Outline). Both sheets 10 are pressed against each other so that there is no space left between them (for clarity, FIG.
Then, an empty space is shown between the sheets 10). Thus, a transparent area twice the margin A remains between the images. Until now, such mammographic images had no transparent margins, which means that they were produced, for example, by a conventional AgX apparatus or by a photothermographic printer. , Because the laser can expose the sheet to its edge.

It is advantageous to print such a mammographic image with a printer having a thermal head because it is less expensive than using an optical thermographic printer. However, when printed by a conventional printer with a thermal head, the transparent area between the two images is annoying on the lightbox.

[0015]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a thermal printer with a thermal head capable of printing a mammography image suitable for diagnosis on a light box. Is to provide.

A further object of the present invention is to provide a method which makes it possible to obtain a mammography image suitable for diagnosis on a light box by a thermal printer with a thermal head. SUMMARY OF THE INVENTION AND TERMINATION OF TERMS The above objects are realized by a thermal printer having a device as claimed in claim 1 and by a thermal printer performing the method as claimed in claim 3.

As shown in FIG. 1, a substantially straight edge 1
The sheet 10 with 1 is precisely aligned according to the invention. There, an image is printed on the sheet leaving a small margin A, for example 1.1 mm, between the image area E and the substantially straight edge 11. Such a small transparent area twice the margin A between the two image areas E is not annoying when viewed on a light box. Due to the fine alignment, the margin A has a nearly constant width, which results in soiling the thermal head as described above.
The image area E approaches the sheet edge 11 too close, there is no danger. One margin, margin A in FIG. 1, may have a smaller width and the other margin, margins B, C and D in FIG. 1, may have a larger width.

In the preferred embodiment of the invention shown in FIG. 2, the substantially straight edge 11 of the sheet 10 is substantially perpendicular to the drum axis 45 of the thermal printer.
Aligned with an endicular alignment axis 25. As shown in FIG. 1, the sheet 10 is about 254 mm.
It may be a substantially rectangular sheet having a standard dimension of 10 inches x 12 inches.
The image is then printed line-wise such that the image line is substantially perpendicular to edge 11, ie edge 1
Is substantially parallel to 2. Preferably, edge 12 is the short, about 254 mm (10 inch) seat edge and edge 11 is the long, about 304.8 mm (12 inch) seat edge. An advantage of this embodiment is that a shorter and therefore cheaper thermal head may be used than if the printed image lines were substantially parallel to the long sheet edge 11.

In the text, the "substantially straight edge" of a sheet is defined as follows. LS is the least squares fit of the edge.
squares fit of the edge). If for every point PT in the line segment S belonging to the edge, thus the total length of the line segment S is at least 80% of the length of the edge, and preferably at least 90% of the length of the edge, The distance d between PT and LS is d
<5 mm, preferably d <3 mm, more preferably d <
The edges are substantially straight if 1 mm and most preferably d <0.5 mm. The distance between the point PT and the least squares segment LS of the straight line in order to anticipate notches, which is quite customary in medical film sheets, is determined by some part of the edge (relative length 20% or 10%). ) Above may be larger.

If L1 * is a line parallel to L1 passing through an arbitrary point 0 taken as an origin and L2 * is a line parallel to L2 passing through 0, between L1 * and L2 * The first line L1 is "substantially parallel" to the second line L2 if the minimum angle α of α is <15 °, preferably α <10 °, more preferably α <5 °.
Is.

If L1 * is a line parallel to L1 passing through an arbitrary point 0 taken as the origin, L2 * is passing through 0.
The minimum angle β between L1 * and L2 * for a line parallel to 2
Is β> 75 °, preferably β> 80 °, more preferably β> 85 °, the first line L1 is the second line L2.
To "substantially perpendicular"
Is.

If it is a vertical line
A line is "substantially vertical (sub) if substantially parallel to e).
stantially vertical) ", and the vertical line has the same direction as gravity.

"Substantially horizo
ntal) "line is substantially perpendicular to the vertical line.

A sheet is "subtantially rectangular" if it has four substantially straight edges and, as noted above, if adjacent edges are substantially perpendicular to each other. "is there.

Further advantages and embodiments of the present invention will be apparent from the following description and drawings.

[0026]

2 shows a first embodiment of the device according to the invention. The sheet 10, which may be fed from the sheet tray in the thermal printer, has two supporting stops.
tops) 27 and 28. Now the sheet is
The first non-aligned positio shown in
n). To precisely align sheet 10, it is moved from this first unaligned position to a second aligned position (not shown), where substantially straight edge 11 of sheet 10 is two. Two alignment stops (alignment
stops) 21 and 22 contact. In the embodiment of FIG. 2, the sheet 10 contacts the alignment stops 21, 22 at points Q ₁ and Q ₂ in the second aligned position. These two points define an alignment axis 25. In the second aligned position, the sheet 10 is thus aligned with its alignment axis 25 at its substantially straight edge 11.

In order to obtain a precisely defined position of the aligned sheet 10, the two supporting stops 27, 28
Only one of which supports sheet 10 in its second aligned position. In the embodiment of FIG. 2, the sheet 10 is in its second aligned position the first and second alignment stops 21,
22 and the first support stop 27, but it does not contact the second support stop 28. Furthermore, the sheet 10 comes into contact with a contact element 34 which pushes the sheet 10 against the alignment stops 21,22. As shown in FIG. 2, the sheet 10 is substantially rectangular. Furthermore,
The alignment axis 25 is substantially vertical. The first support stop 27 is positioned higher than the second support stop 28, ie y ₂₇ > y ₂₈ , where y ₂₇ and y ₂₈ are the first alignment stop 27 and the second alignment stop 27, respectively. It is a coordinate with respect to the vertical axis y of the alignment stop portion 28. This way, sheet 1
When 0 contacts the alignment stops 21 and 22, it does not contact the second support stop 28.

In the preferred embodiment of the invention, the sheet 10
The first support stop 27 that supports the second support position 28 is closer to the alignment axis 25 than the second support stop 28, i.e., in FIG. 2, the distance d ₂₇ <d _28. Is.
In this way, if the second aligned position is d ₂₇ > d ₂₈
Is more stable than

FIG. 3 shows another embodiment of the present invention.
In contrast to the embodiment shown in FIG. 2, in the embodiment of FIG. 3, the support stops 27 and 28 each contact a different edge of the sheet 10 in its first unaligned position to cause the first stop to move. The support stop 27 contacts the edge 14, while the second support stop 28 contacts the edge 13.

The sheet 10 is moved by its moving means 30 to its second aligned position. An embodiment of the moving means 30 is shown diagrammatically in FIG. 2, which comprises an electromagnet 31, a resilient element 32 such as a spring, a lever 33 pivotable about a point P and a contact element 34 on the lever 33. To move the seat 10, the electromagnet 31 is energized and the lever 33 and the lever 3
3 and the contact element 34 on it in the direction of arrow R. The contact element 34 contacts the edge 13 of the sheet 10 and pushes the sheet 10 against the alignment stops 21 and 22. The lever 33 is used to increase the stroke of the electromagnet 31. The advantage of the elastic element 32 is that if the elastic element 32 is omitted, a given force is applied to the edge 13 without forcing the edge 13 to move beyond a fixed displacement. Forcing a fixed displacement causes the sheet 10 to deform by pressing the sheet 10 against the alignment stops 21 and 22. On the other hand, applying a force through the elastic element 32 causes the sheet 10 to move to the alignment stop 2
Gently press against 1 and 22. Moving means 3 shown in FIG.
Instead of 0, any other means of movement known in the art may be used.

Preferably, the sheet 10 is aligned with the stop 2 for alignment.
Before moving relative to 1 and 22, the seat 10 is given a slight touch. This touch means 30
May be given by The purpose of this touch is sheet 1
A good first unaligned position of 0 is obtained, because dropping the sheet 10 may, for example, cause it to be poorly supported by the support stops 27 and 28. . In the embodiment of FIG. 2, the touching action of the sheet is achieved by briefly energizing the electromagnet 31 shortly before the electromagnet 31 is energized to move the sheet. The complete cycle of touching and moving the seat 10 is quite short, for example less than 1 second.

In the preferred embodiment of the present invention, at least one of the alignment stops 21 and 22 is adjustable. Figure 2
In this embodiment, the alignment stop 21 is adjustable. Point Q ₁ is the contact point of the alignment stop 21 with the sheet 10 at its second aligned position. By rotating the alignment stop 21 about its pivot point 24, the contact point Q ₁ moves towards or away from the pivot point 24, which results in an arc 23 in which Q ₁ is located. This is because it is positioned eccentrically with respect to the pivot point 24.

In another embodiment of the invention, the first and second alignment stops 21 and 22 are aligned in their second alignment by the first and second alignment stops 21 and 22. Both parts of one element that contact the sheet 10 in the raised position.

The advantage of the device of the present invention is that it is simple and inexpensive and, most likely, allows for precise sheet alignment.

After aligning the sheets, an image may be printed on the sheets in a thermal printer having a thermal head. As shown in FIG. 2, the drum axis 45 of the thermal printer is preferably substantially perpendicular to the alignment axis 25. The printing operation proceeds as follows.
The aligned sheet is captured by a transport mechanism within the thermal printer-the transport system may include the thermal head and the drum. The displacement means are now switched off, that is, in the embodiment of FIG. 2, the electromagnet 31 is deenergized so that the contact element 34 is withdrawn from the seat 10. The image is printed in line while the sheet 10 is advanced between the thermal head and the drum. In the embodiment shown in FIG. 2, the image line is the sheet 10.
Substantially parallel to the edge 12 (after alignment). The image is printed with a small and almost constant margin adjacent the substantially straight edge 11. Preferably, the alignment axis 2 as shown in FIG. 2 where y represents the vertical axis.
5 is substantially vertical and the drum axis 45 is preferably substantially horizontal.

To calibrate the alignment device, special test images may be written, preferably at the factory during production of the thermal printer. Using the measurements of this test image, the alignment device is then adjusted, for example by adjusting the alignment stop 21 of FIG. In this way, the small margin of the sheet-that is, the margin A in Figure 1-will have an almost constant width. The position of the thermal head along its axis may be adjusted to set the size of the margin width (the axis of the thermal head being substantially parallel to the drum axis 45). .

Example The matching device shown in FIG. 2 has the following coordinates with respect to the axis y: y ₂₈ = 0; y ₂₇ = 0.2 mm; y ₂₄ = 41.6 mm; y ₂₂ = 206.6 mm; y ₃₄ = 131.1 mm Y ₄₅ = 295.4 mm; and the following distances: d ₂₇ = 42 mm; d ₂₈ = 214 mm; The sheet 10 is a heat-sensitive sheet: -with a support of poly (ethyleneterephtalate) having a thickness of 0.18 mm, -dimension 302.5 mm (length of edges 11 and 13) x 2
It has a 52 mm (length of edges 12 and 14) and a perpendicularity of less than 1.5 mm with respect to 300 mm.

The present invention discloses the following: A device for aligning the sheet 10, but in case the sheet has a substantially straight edge 11, the device comprising two aligning stops 21, 22, which define an aligning axis 25. , A first and second support stop 27, 28 for supporting the sheet against gravity at a first unaligned position of the sheet 10, and a second aligned position from the first unaligned position. Seat 10 to the open position
Moving means 30 for moving the sheet, the substantially straight edge 11 of the sheet 10 being in contact with the two alignment stops 21, 22 in the second aligned position. And the first and second support stops 27, 2
8 is the second support stop 2 in which the first support stop 27 supports the sheet at the second aligned position.
It is positioned to support the sheet without eight. The device, but from the alignment axis 25 to the first
A device in which the support stop 27 is positioned at a distance d ₂₇ shorter than the second support stop 28. A device which is positioned with respect to the vertical axis y at a height coordinate y ₂₇ where the first support stop 27 is larger than the second support stop 28. A device, but the two matching stops 21,2
A device in which at least one 21 of the two is adjustable. -A device, but said moving means 30 are elastic elements 32
With a device. A thermal printer having the above device. A thermal printer, further comprising a thermal head for line-wise printing an image on the sheet 10, and a drum for transporting the sheet 10 past the thermal head. And the drum has a drum axis 45 substantially perpendicular to the alignment axis 25. A method for aligning the sheets 10, which method comprises: a. Dropping the sheet 10 by gravity, b. Next, a step of supporting the seat 10 by the first and second support stop portions 27 and 28, and d. Next, a substantially straight edge 1 of the sheet 10
Moving 1 towards the two alignment stops 21, 22; e. Next, the first support stop portion 27 causes the seat 1 to move.
While supporting the sheet 10 without the second support stop 28 supporting 0, the substantially straight edge 11 of the sheet 10 is moved to the two alignment stops 21, 22.
And a step of moving relative to the method. -A method, the method further comprising c. A step of applying a touch to the sheet 10, the step c following the step b, and the step d.
Preceding the method. A method for printing an image on a sheet 10 in a thermal printer, the method being the step of aligning the sheet 10 as described above, wherein the sheet 10 contacts the sheet 10. Contacting means 3
4, the aligning step moved in step e, the step of catching the sheet 10 by a transport mechanism, the step of withdrawing the contact means 34 from the sheet 10, and the thermal head for writing an image on the sheet 10. Image-wise heating the method.

Those skilled in the art will appreciate that many variations and modifications can be made to the above disclosed embodiments which are not outside the scope of the present invention.

The features and aspects of the present invention are as follows.

1. A device for aligning a sheet (10), wherein the sheet (10) has a substantially straight edge (11), for two alignments defining an alignment axis (25). Stop (2
1, 22), and a first (27) and a second (28) support stop for supporting the sheet (10) against gravity at a first unaligned position of the sheet (10). -Moving means (30) for moving said sheet (10) from said first unaligned position to a second aligned position, said substantially straight line of said sheet (10) The edge (11) of said contacting said two alignment stops (21, 22) in said second aligned position,
And the second supporting stop (27, 28) does not have the second supporting stop (28) in which the first supporting stop (27) supports the sheet at the second aligned position. Device for aligning a sheet (10), characterized in that it is positioned to support said sheet.

2. A thermal printer having the device of the above item 1.

3. A method for aligning sheets (10) comprises: a. Dropping the sheet (10) by gravity, b. Next, the sheet (10) is first (27) and second.
(28) A process of supporting with a supporting stop, and d. Then moving the substantially straight edge (11) of the sheet (10) towards the two alignment stops (21, 22); e. Next, while the first support stop (27) supports the seat (10) without the second support stop (28) supporting the seat (10), the seat (10) is supported. Said substantially straight edge (11) of said 2
A step of moving relative to one alignment stop (21, 22).

The present invention will be described with reference to the following drawings, which are not intended to limit the invention thereto.

[Brief description of drawings]

FIG. 1 shows two mammography images.

FIG. 2 shows an example of a device of the invention.

FIG. 3 shows another embodiment of the device of the present invention.

[Explanation of symbols]

10 sheet 11, 12 edge 13, 14 edge 15 contour 21, 22 alignment stop 23 arc 24 point 25 alignment axis 27, 28 support stop 30 moving means 31 electromagnet 32 elastic element 33 lever 34 contact element 45 drum axis d ₂₇ , d ₂₈ Distance y Vertical axis y ₂₂ , y ₂₄ , y ₂₇ , y ₂₈ , y ₃₄ , y ₄₅ Coordinates A, B, C, D Margin E Image range P, Q ₁ , Q ₂ Point R Arrow

Continued front page    (72) Inventor Chris Bullindox             Belgium Bee 2640 Maltcell Septes             Trat 27 Agfa-Gewert Na             Murose Fuennaught Shyt F-term (reference) 2C058 AB15 AC06 AE02 AF33 GB13                       GB32 GB33                 3F102 AA11 AB01 BA02 BB02 DA02                 3F106 CA04 CA23 LA07 LB03

Claims (2)

[Claims] 1. A device for aligning a sheet (10), said sheet (10) having a substantially straight edge (11), wherein-defining an alignment axis (25). Two matching stops (2
1, 22), and a first (27) and a second (28) support stop for supporting the sheet (10) against gravity at a first unaligned position of the sheet (10). -Moving means (30) for moving said sheet (10) from said first unaligned position to a second aligned position, said substantially straight line of said sheet (10) The edge (11) of the first contacting stop (21, 22) for alignment at the second aligned position, the first and second support stops (27, 28) at the second alignment position. The first support stop (27) at the two aligned positions
The second support stop (28) for supporting the seat
Device for aligning a sheet (10), characterized in that it is positioned to support said sheet without. 2. A method for aligning sheets (10), comprising: a. Dropping the sheet (10) by gravity, b. Next, the sheet (10) is first (27) and second.
(28) A process of supporting with a supporting stop, and d. Then moving the substantially straight edge (11) of the sheet (10) towards the two alignment stops (21, 22); e. Next, while the first support stop (27) supports the seat (10) without the second support stop (28) supporting the seat (10), the seat (10) is supported. Said substantially straight edge (11) of said 2
A step of moving relative to one alignment stop (21, 22).