JPH054448A - Recording device - Google Patents

Abstract

(57) [Abstract] [Object] A recording apparatus of the present invention aims to accurately erase an image. A recording apparatus according to the present invention corresponds to a calculation unit that calculates a ratio of recording information based on recording information recorded on a recording medium when recording a visible image on the recording medium, and a calculation result. An energy calculation unit that calculates the recording energy applied to the recording medium based on the weighting table, and the energy obtained by this energy calculation unit can be selectively applied to the recording medium based on the recording information recorded on the recording medium. The recording unit records a visual image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for recording and erasing a visible image on a recording medium on which recording and erasing of a visible image are repeated.

[0002]

2. Description of the Related Art Conventionally, in hard copy recording, an image is formed on a recording medium such as paper from the outside with a visual material such as ink or toner, or a recording layer is formed on a base material such as thermal recording paper. Was provided and a permanent image was recorded by forming a visible image on this recording layer.

However, with the construction of various network networks and the widespread use of facsimiles and copying machines, a rapid increase in the consumption of these recording materials causes problems of natural destruction such as deforestation and social problems such as garbage disposal. There is. In order to deal with these problems, it is strongly required to reduce the consumption of recording material such as reproduction of recording paper. For this task,
Attention has been focused on recording materials that can be repeatedly recorded / erased.

As a material having such characteristics, for example, as disclosed in JP-A-55-154198, a recording material capable of reversibly changing both transparent and opaque states depending on the temperature applied to the recording material. Is proposed. For example, in the case where the recording material is in a white turbid state at room temperature T ₁ , when the temperature is raised from T ₁ to a temperature T ₂ , the white turbid state is changed to a transparent state, and the temperature is room temperature T ₁
Even if it returns to, it keeps the transparent state. Then, the temperature of the recording material is raised from the normal temperature T ₁ to a temperature T higher than the temperature T _{2.
When the} temperature is raised to ₃ , the recording material changes from a transparent state to a cloudy state, and when the temperature is returned to room temperature T ₁ , the cloudy state is maintained as it is. This change can be repeatedly reproduced.

However, when repetitive recording is performed using a thermal head using such a recording material, it is also examined in "Proceedings of the 4th Non-Impact Printing Technology Symposium, 3-2, p57, 1987". Although the results have been reported, there is a phenomenon that the resolution is deteriorated due to the recording temperature of the thermal head during recording.

[0006]

However, the rewritable and rewritable material has a recording temperature range (about 100 to 16).
0 ° C. Temperature range is about 60 ℃ and erase temperature range (about 70-1)
00 ° C. The temperature range is about 30 ° C)
Generally, the erase temperature range is narrow. Therefore, when recording, it is relatively easy to control the temperature of the recording means, but when erasing, it is very difficult to control the temperature of the erasing means, so that the image cannot be erased accurately. There was a problem. Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a recording apparatus capable of accurately erasing an image.

[0007]

In the present invention, in order to solve the above-mentioned problems, recording energy for recording a visible image on a recording medium in which a visible image is recorded or erased in accordance with applied heat energy or a recording energy Recording means for recording a visible image on a recording medium by giving erasing energy for erasing a visual image; and a plurality of weighting tables composed of weighting information for recording energy or erasing energy given to the recording medium by the recording means. A calculating means for calculating the ratio of the recording information already recorded on the recording medium based on the recording information recorded on the recording medium by the recording means; The recording energy given to the recording medium by the recording means on the basis of the selecting means for selecting and the weighting table selected by the selecting means. An energy calculating means for calculating a formate and erase energy, characterized by comprising a control means for controlling the application of the recording medium by the recording means of the recording energy and erasing energy calculated by the energy calculating means.

[0008]

According to the recording apparatus of the present invention, when a visible image is recorded on a recording medium, a plurality of weighting tables for recording energy or erasing energy to be recorded are provided, and the ratio of the recording information based on the already recorded recording information. Is calculated, one weighting table is selected based on the calculation result, the recording energy and the erasing energy are calculated based on this weighting table, and the calculated energy is applied to the recording medium to record a visible image. I do.

[0009]

FIG. 1 shows a schematic structure of an embodiment of a recording apparatus of the present invention. The recording apparatus of the present invention includes a recording information storage memory 11 that stores recording information, a dot rate calculation unit 17 that calculates a dot rate based on the recording information stored in the recording information storage memory 11, and a weighting that stores weighting information. The weighting table selecting unit 21 that selects one weighting table from the weighting table 13 according to the output of the table 13 and the dot rate calculating unit 17, and the applied energy based on the weighting table 13 selected by the weighting table selecting unit 21. The applied energy calculation unit 15 for calculating,
An image based on the applied energy control unit 23 that controls the applied energy applied based on the recording information stored in the recording information storage memory 11, the information from the applied energy calculation unit 15, and the applied energy information from the applied energy control unit 23. Is composed of a recording unit 19 for recording. The recording information storage memory 11 stores image data to be recorded and data such as printing and non-printing areas. The weighting table 13 is used to obtain a microscopic heat storage correction amount in the vicinity of the pixel currently to be recorded in the recording unit 19. The applied energy calculation unit 15 calculates the energy to be applied to the recording unit 19 from the weighting table 13.

The dot rate calculation unit 17 sets a predetermined number of print data corresponding to the mark dots on which an image is recorded and a non-print data number corresponding to a space dot on which no image is recorded in the recording information data. The ratio of the number of correction data obtained by multiplying the coefficient to the predetermined number of record information data is calculated. The weighting table selection unit 21 selects one weighting table from a plurality of weighting tables.

In the applied energy control section 23, if the information to be recorded on the recording medium is a mark dot forming an image, the recording energy obtained by the applied energy calculation section 15 is the same as the recording energy, and if it is a space dot not forming an image. Erase energy is applied to the recording unit 19.

The recording unit 19 records and erases a visible image on a recording medium where recording and erasing of a visible image are repeated by the applied energy. In this embodiment, a line type thermal head is used for the recording section. Next, a recording method using the recording apparatus of the present invention will be described with reference to FIG.

The case where the character "L" is directly overwritten on the character "I" will be described below with reference to FIG. At present, the rewritable recording medium 1 has a structure shown in FIG.
As shown in (a), the character "I" is recorded. When overwriting recording of the character "L" on the rewritable recording medium 1 as shown in FIG.
As shown in (b), a part of the non-erased character "I" and a part of the recorded character "L" are mixed. In FIG. 2B, the heating resistor array 2 of the thermal head is in contact with the rewritable recording medium 1, and the arrangement of the heating resistors 2 is perpendicular to the recording direction in which the heating resistors 2 record. It is arranged. The heating resistors 2 are provided in a sufficient number to record the width of the rewritable recording medium 1 in the direction perpendicular to the recording direction. 3 is a part of the image "I" which has been already recorded, and 4 is a part of the image "L" which is currently being recorded. 5 is the erased image
Part of I ″, 6 is a re-recorded part. When recording on the rewritable recording medium 1, the recording medium 1 heats up the heating resistor 2 corresponding to the pixel of interest, which is a mark dot. Recording is performed by raising the temperature, and when erasing, recording is performed by raising the heating resistor 2 corresponding to the pixel of interest, which is a space dot, to a temperature at which the recording medium 1 rises to a transparent temperature range. Is done.

As described above, while the rewritable recording medium 1 is conveyed in the recording direction under the heating resistor array 2 of the fixed thermal head, the mark dot for forming an image has a recording temperature at a recording temperature and a space for not forming an image. By selectively heating the heating resistor 2 so that the dots reach the erasing temperature, a new image 4 is recorded and at the same time the old image 3 is recorded.
That is, so-called overwrite recording is realized. The recording layer of the rewritable recording medium used here becomes transparent at about 70 to 80 ° C, and the cloudiness is saturated at about 90 ° C or higher. The upper limit of the heating temperature is determined by the heat resistance of the protective layer or recording layer. The temperature of this recording medium 1 was about 130 ° C.

In the above description, the energization time to the heating resistor 2 is simply divided into two types in order to set the temperature of the recording layer to the cloudy temperature range or the erasing temperature range, but the heat generated by the actual thermal head is used. In recording, even if the energization time is the same depending on the heat storage of the thermal head, heat generation history, environment, etc.
It is known that the temperature profile of the heating resistor is not always the same. In this rewritable recording, it is important to give energy to the recording material so that the recording layer temperature becomes the cloudy temperature range or the transparent temperature range regardless of the heat storage, the heat generation history, the environment and the like. Therefore, by controlling the applied energy in consideration of these factors, the recording layer temperature can be raised to a predetermined temperature more accurately. Hereinafter, it will be described in detail that the above-described control of the applied energy in the recording apparatus of the present invention can be performed more accurately.

In FIG. 1, image data is read from the recording information storage memory 11, and the applied energy calculating unit 15 considers the microscopic heat accumulation near the target pixel from the read image data and the weighting table. , The applied energy amount of the pixel of interest is calculated. In parallel with this, the image data is also input to the dot rate calculation unit 17, the dot rate in the reference area is obtained by the method described later, and the value is output to the applied energy correction unit 21. The applied energy correction unit 21 corrects the value of the amount of energy calculated by the applied energy calculation unit 15 based on the dot rate calculated by the dot rate calculation unit 17. The applied energy control unit 23
The image data of the pixel of interest is received from the recording information storage memory 11, and if the pixel of interest is a mark dot, the recording energy obtained as described above, and if the pixel of interest is a space dot, the erase energy obtained similarly is recorded. Give to 19. Next, the correction of the energization time of the pixel of interest will be described.

A method of calculating the dot rate in the dot rate calculating section will be described with reference to FIGS. 3 (a) and 3 (b). Figure 3 (a)
In, a rectangular (solid line) area is a recording area, and a halftone dot area (W dots × N lines) therein is a reference area for dot rate calculation. In the case of the present embodiment, the number of dots in the main scanning direction of the reference area is equal to the total number of dots W in the main scanning direction of the recording area, 448 dots, and the number of lines N in the sub scanning direction is a value between 1 and 32 lines. , 24 lines. For example, the lines to be recorded are 1, 2, ..., i, ...
The reference area A is used between N−1 and N, and the reference area B is used when the recording lines are N + 1, N + 2, ..., 2N−1, 2N. FIG. 3B shows the relationship between the line to be recorded and the reference area. For example, if the size of the reference area is (W
(Dots × N lines), when recording the current i-line, reference is made to the shaded area past the i-line, and mark dots and space dots in the reference area are counted by multiplying by a predetermined coefficient shown below, Find the rate. The count value C _t = Σ (W _D) dot rate (with respect to the reference _{area) R D = C t / (} W × N) × 100 (%) W: number of the main scanning direction of the reference area dot N: the reference area sub Number of lines in the scanning direction W _D : Weight value W _D = 1 ... (Mark dot) W _D = k (0 <k <1) ... (Space dot) = 0.5

The weighting table selection section 21 selects a weighting table for heat storage control from the dot ratios in the reference area described above. In this embodiment, five types of weighting tables are set as follows and selected as follows. 0% ≤ dot rate <10% → (select table 1) 10% ≤ dot rate <25% → (select table 2) 25% ≤ dot rate <45% → (select table 3) 45% ≤ dot rate <70% → (select table 4) 70% ≤ dot rate ≤ 100% → (select table 5)

The applied energy calculator 15 uses the weighting table 13 to determine the applied energy amount of the pixel of interest. FIG. 4A shows image data corresponding to the weighting table, and FIG. 4B shows an example of the weighting table 13.
In this embodiment, a weighting table having a size of (3 dots × 3 dots) is used. For example, M: −0.3,
An element having S: -0.1 has a weight value of -0.3 when the image data corresponding to the element is a mark dot that forms an image, and a weight value of -0 when the image data is a space dot that does not form an image. . 1 is represented. The elements corresponding to the pixel of interest are M: 8 and S: 5,
This value corresponds to the basic energization time of the mark dot and the space dot, and the value obtained by adding the weight of each element to these values becomes the energization time before correction of this pixel of interest.

The control method used in the recording apparatus of the present invention will be referred to as "semi-macro control", and the case where the energization time is corrected by the semi-macro control will be described below with reference to FIG.

As described above, in the recording apparatus of the present invention, in order to drive the heating resistor of the thermal head not only for the mark dots but also for the space dots, as shown in FIG. Even in the case of recording such a print pattern, the temperature of the heating resistor rapidly rises, as in the case of all-mark recording in the conventional thermal head recording apparatus. The temperature increase rate is not constant, and the temperature increase rate is high in the range of the beginning of continuous energization, and the increase rate gradually decreases as the time increases.

The semi-macro control applied to the recording apparatus of the present invention is a recording apparatus which constantly heats a thermal head like the recording apparatus of the present invention and which causes a characteristic temperature change depending on time as shown in FIG. It works effectively.

[0023]

As described above, according to the recording apparatus of the present invention, it is possible to accurately erase an image.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a recording apparatus that is an embodiment of the present invention.

2A and 2B show an example of overwrite recording when the recording method of the present invention is used. FIG. 2A is the first recorded image, FIG. 2C is the rewritten image, and FIG. )
FIG. 6 is a diagram for explaining a state of overwrite recording.

3A and 3B are reference areas used in a dot rate calculation unit of the recording apparatus of the present invention, where FIG. 3A shows a relationship between a recording area and a reference area, and FIG. 3B shows a relationship between a recording line and a reference area. Is.

FIG. 4 shows an example of a weighting table used in the present invention, (a) shows image data corresponding to the weighting table, and (b) shows an example of the weighting table.

FIG. 5 is a diagram showing a time-temperature curve of a heating resistor of a thermal head.

[Explanation of symbols]

 11 Recording Information Storage Memory 13 Weighting Table 15 Applied Energy Calculation Section 17 Dot Rate Calculation Section 19 Recording Section 21 Weighting Table Selection Section 23 Applied Energy Control Section

Claims (1)

Claim: What is claimed is: 1. A recording energy for recording a visible image on a recording medium in which a visible image is recorded or erased according to the applied thermal energy or an erasing energy for erasing the visible image. Recording means for recording a visible image on a recording medium, a plurality of weighting tables constituted by weighting information for recording energy or erasing energy applied to the recording medium by the recording means, and the recording means for recording Calculating means for calculating the ratio of the recording information already recorded on the recording medium based on the recording information recorded on the medium;
Selecting means for selecting one weighting table from the plurality of weighting tables based on the calculation of the calculating means;
Energy calculating means for calculating the recording energy and the erasing energy applied to the recording medium by the recording means based on the weighting table selected by the selecting means, and the recording energy and the erasing energy calculated by the energy calculating means. And a control means for controlling application of the recording medium to the recording medium by the recording means.