JPH0911640A - Image recording method and apparatus - Google Patents

Abstract

PURPOSE: To simply discriminate whether a recording image is altered while keeping the simplicity of thermal recording by thermally recording a first image on a recording medium at first temp. and thermally recording a second image at second temp. CONSTITUTION: A second image (background image) 7 is recorded at higher temp. as compared with a first image (character image) 6. Therefore, the first image can not be recorded on the second image. When the second image 7 is recorded on the first already recorded image 6, the second image 7 become prefential at the overlapped part to omit a part of the first recorded image 6. Therefore, the presence of a postscript can be discriminated by the disturbance of the second image 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording method for heating and recording a character image and a background image on a multicolor thermosensitive recording medium which develops different colors by heating at different temperatures. The present invention relates to an image recording device.

[0002]

2. Description of the Related Art At present, thermal recording paper is used in various fields, for example, recording paper for word processors, recording paper for facsimile, transportation tickets, bar code labels, and the like.

The advantages of using heat-sensitive recording paper are that the configuration of the recording apparatus is simple, no replenishment is required other than paper, little maintenance is required, and running costs are low. On the contrary, there is a drawback that the security of the recorded image is low because it is not suitable for recording a color image and can be easily recorded by applying heat having a temperature higher than the coloring temperature.

[0004] As a method for improving the disadvantages of such heat-sensitive recording, a method for recording a color image is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-175055.
A thermal recording paper that changes its color depending on the amount of applied heat is used, and a heat generating unit equipped with a plurality of heat generating elements is provided to control the heat energy of each heat generating element independently. There is a printer.

However, there is no effective means for the security of recorded images, and heat-sensitive recording is used for tickets for transportation, but for commuter tickets used for a long time,
Generally, the melt transfer recording method is used. In the melt transfer recording method, the security of the recorded image is improved by increasing the robustness of the image, but there is no security effect for conscious additional recording.

Further, in general, when a color image is recorded, the ink ribbons of different colors are used and a plurality of colors are superposed and recorded. In this case, since ink ribbons of a plurality of colors are required in addition to the recording medium, maintenance work is increased.

[0007]

As described above, although heat-sensitive recording is easy to handle, there is a problem that the recorded image can be easily modified by applying heat above the coloring temperature, and the security function is very weak. .

Therefore, an object of the present invention is to provide an image recording method and an image recording apparatus with high security that can easily identify whether or not a recorded image has been modified while having the simplicity of thermal recording.

[0009]

The image recording method of the present invention is an image recording method for heating and recording an image on a recording medium that develops different colors by heating at different temperatures.
The first image is heat-recorded on the recording medium at a first temperature, and the second image is heat-recorded at a second temperature.

The image recording method of the present invention is an image recording method in which an image is heat-recorded on a recording medium that develops different colors by heating at different temperatures, and the first image is recorded on the recording medium. Is simultaneously heated and recorded at the first temperature, and at the same time, the second image is heated and recorded at the second temperature.

Further, the image recording method of the present invention is an image recording method in which an image is heat-recorded on a recording medium that develops different colors by heating at different temperatures, and a character image is first recorded on the recording medium. The recording is performed at a temperature of 1 and at the same time, the background image is heated and recorded at a second temperature higher than the first temperature.

Further, the image recording method of the present invention is an image recording method in which an image is heat-recorded on a recording medium that develops different colors by heating at different temperatures, and a character image is first recorded on the recording medium. While heat-recording at a temperature of 1, a background image is heat-recorded at a second temperature higher than the first temperature, and a character image to be heat-recorded at the first temperature and heat-recording at the second temperature. When the recording positions of the background image are the same, the character image to be heated and recorded at the first temperature is preferentially recorded.

The image recording method of the present invention is an image recording method for heating and recording an image on a recording medium that develops different colors by heating at different temperatures, wherein a character image is recorded on the recording medium. It is characterized in that the background image is heated and recorded at a second temperature higher than the first temperature at the same time as the heating and recording at a temperature of 1.

Further, the image recording method of the present invention is an image recording method in which an image is heat-recorded on a recording medium which develops different colors by heating at different temperatures, and a character image is first recorded on the recording medium. The heat recording is performed at a temperature of 1, and the contour image of the character image is heated and recorded at a second temperature higher than the first temperature.

Further, the image recording method of the present invention is applied to a recording medium which develops different colors by heating at different temperatures.
An image recording method for heat-recording an image using a thermal recording means, wherein a thermal head is used as the thermal recording means,
According to the image to be recorded, each heating element of the thermal head is independently controlled to have a first temperature or a second temperature higher than the first temperature.
By controlling the temperature of the recording medium, the character image is heated and recorded on the recording medium at the first temperature, and the background image is heated and recorded at the second temperature.

Further, the image recording method of the present invention is applied to a recording medium which develops different colors by heating at different temperatures.
An image recording method for heat-recording an image using a thermal recording means, wherein a thermal head is used as the thermal recording means,
According to the image to be recorded, each heating element of the thermal head is independently controlled to have a first temperature or a second temperature higher than the first temperature.
By controlling the temperature of the recording medium, the character image is heated and recorded on the recording medium at the first temperature, and at the same time, the background image is heated and recorded at the second temperature.

Further, the image recording apparatus of the present invention is an image recording apparatus for heating and recording an image on a recording medium which develops different colors by heating at different temperatures, and a conveying means for conveying the recording medium, Thermal recording means for heating and recording an image on the recording medium conveyed by the conveying means using a heating element, image storage means for respectively storing a character image and a background image to be recorded on the recording medium, and this image An image synthesizing unit for reading and synthesizing the character image and the background image stored in the storage unit, and a pixel to be recorded is cut out from the image synthesized by the image synthesizing unit. When the cut out pixel is a character image, The heating element of the thermal recording means is controlled to heat the recording medium to a first temperature, and when the cut-out pixel is the background image, the heating element of the thermal recording means is recorded. Higher than the body first temperature second
Control means for controlling heating to the above temperature.

[0018]

According to the present invention, since the second image (for example, the background image) is recorded at a higher temperature than the first image (for example, the character image), the first image from the top of the second image is recorded. Can not be recorded. In addition, the first recorded
When the second image is recorded so as to be superimposed on the image of, the second image has priority in the overlapped portion, and a part of the recorded first image is lost. Therefore, the presence or absence of additional recording can be easily identified by the disturbance of the second image. Therefore, it has high security and can be applied to, for example, a cash voucher or a prepaid card.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment will be described. FIG. 1 schematically shows the structure of a multicolor thermal recording medium used in this example. That is, the recording medium 1 is configured by laminating the second recording layer 3, the first recording layer 4, and the protective layer 5 on the base material 2 in this order. In the recording medium 1 of the present embodiment, the first recording layer 4 which is heated at the first temperature (low temperature side) to develop color is red, and the first recording layer 4 which is heated at the second temperature (high temperature side) is second color. The layer 3 shall be colored black.

The first recording layer 4 and the second recording layer 3 are composed of, for example, a heat-sensitive recording layer containing a leuco dye and a color developer as main components. As the leuco dye, for example, a leuco compound of a dye such as a triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, or indolinophthalide-based dye is preferable. As the developer, various electron-accepting compounds which cause the leuco dye to develop color upon contact, such as phenolic compounds, thiophenolic compounds, thiourea derivatives, organic acids and metal salts thereof are preferred.

FIG. 2 shows energy density characteristics when an image is recorded on the recording medium 1 used in this embodiment by using a thermal head (thermal recording means) having a heating element density of 8 elements / mm. The results of measurement using filters for measuring black are shown for both red and black. As is clear from this figure, the energy develops red from about 0.4 mj / dot, and the energy is about 0.
When it is 7 mj / dot or more, a black color starts to be generated, and a red color and a black color are mixed. Furthermore, when the energy is increased to about 1.0 mj / dot or more, the color becomes reddish black.

FIG. 3 shows an example of recording using the image recording method of this embodiment. In this example, it is assumed that the usage history of the user is recorded at any time, such as a prepaid card. On the recording medium 1, a character image 6 as a first image and a background image (background pattern) 7 as a second image are recorded. The character image 6 records the date of use, items, and the amount of money used, and the background image 7 records a horizontal stripe pattern.

To record as shown in FIG. 3, the image to be recorded is separated into a character image and a background image, and (1) only the character image is heated to a first temperature (low temperature). The first energy is applied to the thermal head to record only the character image.

(2) A second energy is applied to the thermal head so that only the background image is heated to the second temperature (high temperature), and the background image is overlaid and recorded. There is a first recording method. That is, the data are recorded in the relationship shown in Table 1 below.

[0025]

[Table 1]

At this time, if the character image corresponding to the first temperature has already been recorded, the character image is not overprinted at the second temperature. As a second recording method, a character image and a background image are combined to form a recorded image, and when the character image is recorded, energy is applied to the heating element of the thermal head so as to reach the first temperature. When a background image is recorded, energy is applied to the heating element of the thermal head so as to reach the second temperature, and by performing these simultaneously, the character image and the background image can be recorded in one pass. it can.

FIG. 4 shows a control flowchart for performing such simultaneous recording. First, the character image to be recorded and the background image stored in the image memory are read (S1). Next, the character image and the background image are combined (S2). This is done according to the rules shown in Table 2 below. In the table, “◯” indicates that the image information is valid, and “x” indicates that the image information is invalid. In the present embodiment, since the character image is preferentially recorded, when both are valid, such as character image = O and background image = O, recording information for character image recording is generated as a recording image.

[0028]

[Table 2]

Next, the pixels to be recorded, that is, the target pixels are cut out from the combined image (S3). If this pixel of interest is a character image, the energy E for heating to the first temperature
If the target pixel is the background image, the energy E2 for heating 1 to the second temperature is selectively and simultaneously applied to the heating elements of the thermal head (S4 to S6) to record 1. The image points of the character image and the background image are recorded on the medium 1 (S7). By performing these operations for all pixels (S8),
One recording operation is completed.

In this case, for example, a line type thermal head is used to perform the above-mentioned energy control for each heating element, so that a character image and a background image can be simultaneously recorded in one pass.

FIG. 5 shows a block diagram of an image recording apparatus for realizing the image recording method for simultaneously recording the character image and the background image described above. That is, a CPU (Central Processing Unit) 8 controls the entire apparatus. ROM (Read Only Memory) 9
A control program for operating the CPU 8 and the like are stored. RAM (random access memory) 1
0 is used as a work area of the CPU 8 and temporarily stores various setting data. Image memory 11
Stores an image to be recorded, and the inside thereof is divided into a character image storage area 11a and a background image storage area 11b.

The transport control unit 12 drives the drive motor of the transport unit 13 that transports the recording medium 1. The sensor 14 detects the conveyed recording medium 1, and the detection signal is used for conveying control of the recording medium 1. Recording control unit 1
Reference numeral 5 controls the timing relationship of the recording operation and cuts out the pixel of interest from the image.

The recording drive section 16 generates a control signal for controlling the drive of the thermal head (recording section) 17. The recording energy control unit 18 calculates the energy value applied to the thermal head 17, and controls the enable pulse of the thermal head 17 based on the calculated energy value.

In such a structure, when the recording operation is started, the CPU 8 first executes the control program stored in the ROM 9. That is, the CPU 8 operates the transport control unit 12 and drives the transport unit 13 to transport the recording medium 1 to the recording position.

Next, the CPU 8 reads out image data from the character image storage area 11a and the background image storage area 11b of the image memory 11, respectively, synthesizes the images, and temporarily stores them in the RAM 10. After that, the image data to be recorded is read from the RAM 10, and the recording control unit 15
Send to The recording control unit 15 cuts out a pixel of interest from the sent image data and sends the pixel of interest data to the recording drive unit 16 and the recording energy control unit 18.

The recording drive section 16 generates the signals (data transfer clock, recording data, latch pulse, enable pulse, etc.) necessary for driving the thermal head 17 as described above. The recording energy control unit 18 calculates the applied energy to the thermal head 17, and controls the enable pulse of the thermal head 17 based on the calculated energy. Various signals generated by the recording drive unit 16 are sent to the thermal head 17 for actual recording.

Next, with reference to FIG. 6 and FIG. 7, description will be made on the high security of the image when the image is recorded by the image recording method of the present embodiment. For example, consider the case of illegally rewriting the character "I" into "T". FIG.
FIG. 6A shows a character “I” recorded by using this image recording method, and FIG. 6B shows a character “T” by using this image recording method.
Is recorded. As mentioned above, the character image is the first
The background image is colored in red (shown by black solid in the figure) at the temperature (low temperature side), and the background image is colored in black (shown by wavy line in the figure) recorded at the second temperature (high temperature side).

When the characters are to be modified, a horizontal bar is recorded at the upper end of this "I" to make it "T", but FIG. 6 (c): When recorded at the first temperature or lower ... do not do.

FIG. 7A: When recorded at the first temperature ...
... Since the character image is recorded between the background images shown by the wavy lines, it is in a mottled state.

FIG. 7B: When recorded at the second temperature ...
... The horizontal bar of "T" is the background color, and the vertical bar of "T" is the character color. Not shown: When recording above the second temperature ... The recording layer is thermally destroyed and no color is developed. Therefore, it is not possible to rewrite, or the fact that it has been rewritten can be easily identified visually.

As described above, when recording is performed using this image recording method, it is difficult to additionally record in the same color as the character image, and therefore it is possible to additionally record only in the same color as the background image. However, as shown in FIGS. 7A and 7B, when a character image is recorded in a color different from the character color, it can be easily visually identified that the image has been rewritten.

Next, the second embodiment will be described. FIG. 8A shows the background image to be recorded at the second temperature in line with the outline of the character image. By doing so, it becomes impossible to add a part of the character image to modify the image.

FIG. 8B shows an ID number (personal identification number).
Is a character image, the rectangular area around the ID number is recorded as the background image at the second temperature. FIG.
A method of recording the background image at the second temperature according to the outline of the character image as in (a) will be described below. The recording medium 1 used here is the same as that described with reference to FIGS. 1 and 2.

FIG. 9 shows a control flow chart of the image recording method of this embodiment. Basically, it is similar to the flowchart shown in FIG. 4, and "reading of image information" in step S1.
Is divided into reading a character image and reading a contour image of the character image. The read character image and the contour image corresponding to the character image are combined to generate a recorded image, and thereafter, recording is performed by the same procedure as in the first embodiment.

FIG. 10 shows a block diagram of an image recording apparatus for realizing the image recording method of this embodiment. The configuration is basically the same as that shown in FIG. 5, but the image memory 11
Is a character image storage area 11a and a contour image storage area 11c
5 and that the character contour image generation unit 19 is added.

In the contour image storage area 11c, the coordinate values of the contours necessary to generate the contour images of the respective character images are stored. For example, when the character "A" is specified, the character "A" is designated. The coordinates of the image outline image are called.

The character contour image generator 19 generates a contour image of a character image. This creates a contour image for actual recording based on the coordinate values of the contour image read from the contour image storage area 11c in the image memory 11.

Next, the security of the image when the image is recorded by the image recording method of this embodiment will be described with reference to FIG. Similar to the case of the first embodiment described above, consider the case where the character "I" is illegally rewritten to "T". FIG. 11A shows the character "I" when this image recording method is used.
FIG. 11B shows that the character “T” is recorded using this image recording method. As described above, the character image is red (black solid in the figure) recorded at the first temperature (low temperature side), and the contour image of the character image is black (second figure) recorded at the second temperature (high temperature side). It is colored with a wavy line).

When a character is to be modified, a horizontal bar is recorded at the upper end of this "I" to make it "T". Fig. 11 (c): When recorded at the first temperature or lower ... do not do.

FIG. 11 (d): When recording at the first temperature ... Since the portion of the contour image shown by dots does not develop color, the horizontal bar of "T" is not connected.

FIG. 11E: When recorded at the second temperature ... The horizontal bar of "T" is the background color and "T"
The vertical bar of is the character color. Not shown: When recording above the second temperature ... The recording layer is thermally destroyed and no color is developed. Therefore, it is not possible to rewrite, or the fact that it has been rewritten can be easily identified visually.

Therefore, as shown in FIGS. 11 (a) and 11 (b), since the contour image of the character image is colored in a color different from that of the character image, it is possible to easily rewrite it visually by additionally writing. Can be identified.

As described above, by using this image recording method, it is possible to record an image with high security. Therefore, for example, it can be applied to a cash voucher or a prepaid card that requires high security, and can exert a remarkable effect.

[0054]

As described above in detail, according to the present invention, there is provided an image recording method and an image recording apparatus having high security that can easily identify whether or not a recorded image has been modified while having the simplicity of thermal recording. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a layer structure of a recording medium according to a first embodiment of the invention.

FIG. 2 is a diagram showing color development characteristics of a recording medium in a first embodiment by a thermal head.

FIG. 3 is a diagram showing an example of a recorded result in the first embodiment.

FIG. 4 is a control flowchart of an image recording method in the first embodiment.

FIG. 5 is a block diagram showing the configuration of an image recording apparatus for realizing the image recording method in the first embodiment.

FIG. 6 is a diagram for explaining the image security of the image recording method in the first embodiment.

FIG. 7 is a diagram for explaining the image security of the image recording method in the first embodiment.

FIG. 8 is a diagram showing an example of a recorded result in the second embodiment of the present invention.

FIG. 9 is a control flowchart of an image recording method in the second embodiment.

FIG. 10 is a block diagram showing the arrangement of an image recording apparatus for realizing the image recording method in the second embodiment.

FIG. 11 is a diagram illustrating image security of the image recording method according to the second embodiment.

[Explanation of symbols]

1 ... Recording medium, 2 ... Substrate, 3 ... Second recording layer, 4 ...
... first recording layer, 5 ... protective layer, 6 ... character image (first image), 7 ... background image (second image), 8 ... CP
U, 9 ... ROM, 10 ... RAM, 11 ... Image memory, 11a ... Character image storage area, 11b ... Background image storage area, 11c ... Contour image storage area, 12 ... Conveyance control section, 13 ...... Conveyor, 15 …… Record controller, 16 ・ ・ ・
Recording drive unit 17, thermal head (thermal recording means) 18, recording energy control unit 19, character outline image generation unit.

Claims (9)

[Claims] 1. An image recording method for recording an image on a recording medium which develops different colors by heating at different temperatures, wherein the first image is recorded on the recording medium by heating at a first temperature. And a second image is heated and recorded at a second temperature. 2. An image recording method for heating and recording an image on a recording medium that develops different colors by heating at different temperatures, wherein the first image is heated and recorded on the recording medium at a first temperature. At the same time, the second image is heated and recorded at the second temperature. 3. An image recording method for heating and recording an image on a recording medium which develops different colors by heating at different temperatures, wherein a character image is heated and recorded on the recording medium at a first temperature. An image recording method, wherein the background image is heated and recorded at a second temperature higher than the first temperature. 4. An image recording method for heating and recording an image on a recording medium which develops different colors by heating at different temperatures, wherein a character image is heated and recorded on the recording medium at a first temperature. , A background image is recorded by heating at a second temperature higher than the first temperature, and is recorded by heating at the first temperature and the second
When the respective recording positions of the background image to be heat-recorded at the temperature are the same, the character image to be heat-recorded at the first temperature is preferentially recorded. 5. An image recording method for heating and recording an image on a recording medium which develops different colors by heating at different temperatures, wherein a character image is heated and recorded on the recording medium at a first temperature. An image recording method, wherein the background image is heated and recorded at a second temperature higher than the first temperature. 6. An image recording method for heating and recording an image on a recording medium which develops different colors by heating at different temperatures, wherein a character image is heated and recorded on the recording medium at a first temperature. An image recording method, wherein the contour image of the character image is heated and recorded at a second temperature higher than the first temperature. 7. An image recording method for thermally recording an image on a recording medium which develops different colors by heating at different temperatures, wherein a thermal head is used as the thermal recording means. By controlling each heating element of the thermal head independently to a first temperature or a second temperature higher than the first temperature in accordance with the image to be recorded, the character image is recorded on the recording medium as the first image. The image recording method is characterized in that the background image is heated and recorded at the second temperature while the heat recording is performed at the above temperature. 8. An image recording method for thermally recording an image on a recording medium which develops different colors by heating at different temperatures, wherein the thermal recording means uses a thermal head. By controlling each heating element of the thermal head independently to a first temperature or a second temperature higher than the first temperature in accordance with the image to be recorded, the character image is recorded on the recording medium as the first image. The image recording method is characterized in that the background image is heated and recorded at the second temperature at the same time as the heat recording is performed at the temperature. 9. An image recording apparatus for heating and recording an image on a recording medium that develops different colors by heating at different temperatures, the conveying means conveying the recording medium, and the conveying means for conveying the recording medium. A thermal recording means for heating and recording an image on a recording medium using a heating element, an image storing means for respectively storing a character image and a background image to be recorded on the recording medium, and a character image stored in the image storing means. And an image synthesizing unit for reading and synthesizing the background image, and a pixel to be recorded is cut out from the image synthesized by the image synthesizing unit. When the cut out pixel is a character image, the heating element of the heat recording unit is The recording medium is controlled to be heated to the first temperature, and when the cut out pixel is the background image,
An image recording apparatus comprising: a control unit configured to control a heating element of the thermal recording unit to heat the recording medium to a second temperature higher than the first temperature.