JPH058505A - Recording medium processing device - Google Patents

Abstract

PURPOSE:To certainly perform recording and erasing of visual images on a recording medium that allows recording and erasing the visual images, by a method wherein recording energy (or erasing energy) is given to the recording medium twice or more corresponding to recording signals within a recording unit of recording information to record (or erase) the visual images. CONSTITUTION:A re-writable recorder has a thermal head 11 that gives a recording material recording and erasing energy, and an energizing time period arithmetic circuit 14 calculates the recording energy to mark dots corresponding to printing data, and the erasing energy to space dots corresponding to non- printing data. Recording material is carried by card a transfer device including a motor 15, and when the front edge is detected by a sensor 18 and a specified position reaches the position of a heating resister of the thermal head, printing or erasing action takes place. In this case, two or more recording signals are generated corresponding to recording information within recording unit of recording information, and recording (or erasing) energy is given to the recording material twice or more corresponding to the recording signals to record (or erase) visual images.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium processing apparatus for processing a recording medium on which a visible image is recorded and erased by heat.

[0002]

2. Description of the Related Art In conventional hard copy recording, an image is formed on a recording material such as paper from the outside with a developing material such as ink or toner, or in some sense, on a base material such as paper such as thermal recording paper. A recording layer is provided and a permanent image is recorded by forming a visible image on this recording layer. However, the rapid increase in the consumption of these recording materials with the construction of various network networks and the spread of facsimiles and copying machines causes problems of natural destruction such as deforestation and social problems such as garbage disposal. 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 problem, a recording material that can be repeatedly recorded and erased has attracted attention.

As a material having such characteristics, there has been proposed a recording material capable of reversibly converting both the transparent state and the cloudy state depending on the temperature applied to the recording material. This recording material has a temperature of T
_{When the} temperature is raised from ₁ to the temperature T ₂ , the cloudy state is changed to the transparent state, and the transparent state is maintained even when the temperature returns to the temperature T ₁ . Then, when the temperature of the recording material is raised from the temperature T ₁ to a temperature T ₃ exceeding the temperature T ₂ and then returned to the temperature T ₁ , the transparent state is changed to the cloudy state and the cloudy state is maintained as it is. This change can be repeatedly reproduced. A study on deterioration of resolution in repetitive recording when recording with a thermal head using such a recording material is reported (Proceedings of the 4th Non-Impact Printing Technology Symposium, 3-2, p57 (Showa 62).
Year)).

[0004]

[Problems to be Solved by the Invention] However, in the past,
When recording and erasing are repeatedly performed on a recording material that can be repeatedly recorded and erased, the recording density of the recorded image is lowered, and erasure leakage occurs, and accurate recording and erasing cannot be performed. was there.

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 medium processing apparatus capable of surely recording and erasing a recording medium.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides recording energy for recording a visible image so that a visible image is recorded and erase energy is eliminated. Generating means for generating record information for recording a visible image on a recording medium from which a visible image is erased by applying, and a recording unit of record information based on the record information generated by the generating means. Generating means for generating a plurality of recording signals, and recording means for recording a visible image by applying recording energy to the recording medium a plurality of times within a recording unit of recording information according to the recording signals generated by the generating means. Erasing means for applying erasing energy to the recording medium to erase the visible image recorded by the recording means.

[0007]

A recording medium processing apparatus of the present invention generates recording information for recording a visible image on a recording medium, and generates a plurality of recording signals in a recording unit of recording information based on the recording information. Recording energy is applied to a recording medium a plurality of times within a recording unit of recording information according to a recording signal to record a visible image, and erasing energy is applied to the recording medium to erase the visible image. ..

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the recording medium processing apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic structure of a rewritable recording apparatus using a thermal head thermal recording means as an energy applying means. Reference numeral 10 is a CPU for controlling the entire apparatus, 11 is a thermal head having a heating resistor for applying heat energy for recording and erasing to a recording material, and 12 is a thermal head drive circuit for controlling energization to the heating resistor. It constitutes the energy applying means 13. Reference numeral 14 is an energization time calculation circuit which is a calculation means for calculating the recording energy to the mark dot corresponding to the print data and the erase energy to the space dot corresponding to the non-print data. A motor as a drive source, 16 a drive circuit for the motor, 17 a conveyance motor control circuit for controlling the drive of the motor, 18 a sensor for detecting the position of the recording material, 19 a character generator,
20 is a RAM and 21 is a ROM. Recording is started when the recording material is conveyed, the leading end is detected by the sensor 18, and the predetermined position comes to the resistance heating element position of the thermal head 11. Print data to be recorded is generated under the control of the CPU 10. The print data is code data, and the code data is converted into bit data by the character generator 19 and stored in the RAM 20. After the code data is converted to bit data, R is issued by the print command from the CPU 10.
Bit data is sequentially read from the AM 20. The energization time of the read bit data is determined by the energization time calculation circuit 14. The thermal head drive circuit 12 operates according to the determined energization time, and the thermal head 11
The heating resistor is selectively heated to write a visible image on the display portion and erase an unnecessary visible image.

Next, the operation of forming and erasing an image on the recording material will be described with reference to FIGS. Reference numeral 25 is a recording material having a recording layer that reversibly exhibits two states, transparent and cloudy, depending on the history temperature.

The recording material 2 will now be described with reference to FIG.
5 will be described. The recording material 25 includes a colored layer 27 on one surface of a base material 26 and a recording layer 2 that reversibly changes between two states, a transparent state and a cloudy state, by heat energy applied.
It is obtained by sequentially stacking 8 and the protective layer 29. The visible image is formed by making the recording layer 28 transparent, and selectively making the recording layer 28 cloudy while the colored layer 27 is used as a background color, and the erasing is performed by making the cloudy image transparent. It The recording layer used here becomes transparent at about 60 ° C. to about 90 ° C., and the cloudiness becomes saturated at about 105 ° C. or higher. The upper limit of the heating temperature is determined by the heat resistance of the protective layer or recording layer.
This card was about 140 ° C.

Reference numeral 26 is a heating resistor array of the thermal head 11. Reference numeral 27 is an already written image, and 28 is an image currently being written. The heating resistor array 26 is provided in a one-to-one correspondence with one dot of the image, and a plurality of heating resistors are arranged in one line in a direction transverse to the traveling direction of the recording material 25 (shown by the arrow). Consists of. The heating resistors are provided in a sufficient number to record the width of the recording material 25 (transverse direction described above). A new image 28 is obtained by selectively heating the heating resistors of the heating resistor array 26 by the recording method according to the present invention while the card is conveyed in the direction of the arrow under the heating resistor array 26 of the fixed thermal head.
Is written at the same time that the previously recorded image 27 is erased, so-called overwrite recording is realized. The solid circles indicate the recording pixels, and the broken circles indicate the erased recording pixels.

Next, the recording and erasing operations will be described in detail with reference to FIG. In this embodiment, the energizing pulse for driving the heating resistor 26 of the thermal head is set to 2 within one dot forming cycle.
The energy for recording or erasing a visible image by being generated twice is applied twice in a dot formation period. 1 dot formation cycle is 4m
In the case of s, mark dot, the pulse energization time is 1 ms, in the case of space dot, the pulse energization time is 0.7 ms, and the thermal head drive voltage is 16V.

FIG. 4 shows the energizing pulse (upper stage) of the thermal head, the temperature of the heating resistor and the recording material (middle and lower stages) when recording / erasing image points (recording unit). Mark dots (recording) are shown on the left side and space dots (erasing) are shown on the right side. In this embodiment, as shown in the upper part of FIG. 4, two energizing pulses are provided within one dot forming time to record on the recording material 25. The energizing pulse to the mark dot or the space dot has the same voltage value and the energizing time is changed. 1 for mark dots
The second pulse raises the temperature of the heating resistor to a temperature at which the recording material can be recorded, that is, a temperature at which the recording material becomes cloudy. The recording material in contact with the heating resistor is heated to the clouding temperature by the heat energy flowing from the heating resistor. When the energization is turned off, the temperature of the heating resistor drops to a temperature that does not change the recording material. According to this, the temperature of the recording material also drops to around room temperature, but the portion to which heat is applied becomes cloudy. The second pulse is also energized for the same time as the first pulse. The temperature of the resistance heating element rises again. As for the temperature of the heating resistor, the highest temperature reaches a little higher than that at the time of the first energization because the heat is accumulated by the first pulse.
The recording material moves by the effective heating length (corresponding to the dot pitch of the visible image) of the heating resistor in the time of one dot forming cycle. Further, since the effective heating area of the heating resistor corresponds to the dot area forming the visible image, the recording material is stopped during the heating of the heating resistor in one dot formation cycle. In the recording material transport mode in which the recording material is transported while the heating resistor is heating, the minimum half of the area of the recording material in which the mark dots are formed is the first area. Heat is applied twice by the second heat generation and the second heat generation. Therefore, when the second heating resistor generates heat, the temperature rises from a state slightly warmer than the initial state. The second heating raises the temperature of the region of the recording material that contacts the heating resistor again to the clouding temperature. Therefore, half of the area of the formed mark dot undergoes whitening twice and the mark dot is formed. In the case of the space dot, the pulse energization time is shorter than that of the mark dot, and therefore the temperature of the heating resistor becomes the maximum temperature at which the cloudy image of the recording material is made transparent. Also in the case of space dots, half of the area of the space dots formed in the same manner as described for the formation of the mark dots is formed through the transparency twice.

As is clear from the above description, in the recording apparatus of the present invention, the energy capable of recording or erasing the visible image of the recording material by one application is recorded twice within one dot forming cycle. It is characterized in that it is applied to the material. The recording layer of the recording material used in this example reversibly exhibits both white turbidity and transparent state. As shown in the lower part of FIG.
There is a range of temperatures that indicate these two states. When the maximum temperature of the recording layer of the recording material reaches these temperature regions, it becomes cloudy or transparent. If the heating temperature of the heating resistor of the thermal head is controlled so that the maximum temperature of the recording material is close to the lower limit temperature of each state, damage due to heat on the surface of the recording layer of the recording material in contact with the heating resistor ( (Effect) is reduced and the repeated use life of the recording material can be extended. However, it is difficult to accurately control the temperature of the heating resistor, and temperature variations generally occur. Also,
The cloudy state and the transparent state do not change in a binary manner but have a transition region as shown in FIG. In this area, the density of dots is likely to change in an area in which a cloudy state and a transparent state are mixed. Therefore, for example, according to the conventional recording method of forming mark dots by applying recording energy once without multiplexing recording energy, a heating resistor is set so that the maximum temperature of the recording material is close to the lower limit temperature of each state. When driven, the density of the mark dots formed is not constant, and in some cases mark dots of extremely low density are formed. As described in the above embodiments, in the recording apparatus of the present invention, the energy for recording a visible image on the recording material or the energy for erasing the visible image is multiplexed to perform dot formation. Even if the heating resistor is driven so that the temperature becomes close to the lower limit temperature of each state, in the case of mark dot formation, dots of sufficient density are erased twice by the effect of erasing twice in the case of space dots. Even if there are mark dots, the erasure is completed completely.

Further, the present inventors investigated the relationship between the clouding temperature and the repeated use life of the cloudy image, and obtained the findings shown in FIG. An image density was measured by heating a recording medium which was transparent as an initial state with a heat roller rotating at a peripheral speed of 40 mm / s with a constant temperature, and the image density was measured. The heat roller temperatures are T _w1 and T _{w2 in the} white turbid saturation concentration region shown in FIG.
And T _w3 were used. As is clear from FIG. 6, the higher the clouding temperature, the greater the change in cloudy density with the increase in the number of repetitions. Therefore, it is desirable to record with the minimum energy to obtain the required concentration.

In the case of recording and erasing a visible image by heating a recording medium using a thermal head, the time for applying heat to the recording medium is extremely short (several ms or less) as compared with a heat roller, and Since it is necessary to raise the temperature of the recording layer of the recording medium to the same temperature in such a short time, the temperature of the heating resistor of the thermal head that contacts the surface of the recording medium becomes several hundreds of degrees. When a high-temperature heat source contacts for an extremely short time in this way, the closer to the contact side of the heat source (heating resistor), the higher the temperature, and the temperature gradient, in the thickness direction of the recording medium, as schematically shown in FIG. It is known that the temperature is steep, the temperature is lower and the temperature gradient becomes gentler as the distance increases. Therefore, since a temperature difference occurs in the recording layer, the temperature of the entire recording layer returns to room temperature after the heat supply from the heating resistor is completed, but the temperature reached by each recording portion is different. When performing cloudy recording, the temperature of each part of the recording layer may be set to be equal to or higher than the minimum clouding temperature as shown in FIG. 5, but the clouding temperature of each part of the recording layer is caused by the temperature gradient in the recording layer described above. Are different. When the clouding temperature is too high, the repeated life becomes short as shown in FIG. On the other hand, when the thickness of the cloudy region in the recording layer is thin, a sufficient cloudy density cannot be obtained. Therefore, it is desirable that the clouding temperature be as low as possible and that the temperature gradient in the recording layer be gentle.

Since the recording apparatus of the present invention multiplexes and applies heat to the recording material as described above, it is sufficient even if the temperature of the applied heat is low as compared with the case of the conventional non-multiplexed recording. In addition, since the temperature history of the recording medium by applying heat twice is almost the same, the maximum temperature of each portion of the recording layer is small, which is advantageous for the repeated life.

In the above description, it has been explained that the energizing time to the heating resistor for making it cloudy or transparent is constant. However, in the thermal head thermal recording means, it is generally known that the maximum attainable temperature of the heating resistor is not necessarily the same even if the energization time is the same due to the heat accumulation and heat generation history of the thermal head. It is important that the energy applying means of the rewritable recording apparatus applies energy to the recording material so that the temperature of the recording layer is in the opaque temperature range or the transparent temperature range. Therefore, the temperature of the recording layer can be more accurately raised to a predetermined temperature by controlling the applied energy in consideration of the heat storage and heat generation history of the thermal head. In this recording apparatus, the energization time calculation circuit 14 performs a calculation for correction.

Calculation of the energization time in the energization time calculation circuit 14 will be described with reference to FIGS. 8 and 9. In this embodiment, the heat storage and heat generation history of the thermal head is predicted from the print data around the mark dot or space dot of interest, which is developed in a bitmap, and the heating resistor is energized corresponding to the position of the mark dot or space dot of interest. You control the time. For example, in this embodiment, when the target data P is in the n line-i column as shown in FIG.
The data included in the matrix of the past two lines and the future one line in the i ± 1 column excluding is referred to. The data on the past line is referred to in order to calculate the thermal energy accumulated in the heating resistor corresponding to the attention data P, and the data on the future line is referred to not to give an excessive energization time. When calculating the energization time, the contribution ratio is weighted by the positional relationship from the data of interest,
The data of the (n-1) th line and the i-th column has the largest contribution rate, and the farther the position, the lower the contribution rate.

FIG. 9 schematically shows the structure of the energization time calculation circuit 14. The print data is supplied to the shift register 30. The shift register 30 converts serially input print data into parallel data, cuts out print data around the print data of interest according to the matrix size, and supplies the energization time calculation unit 31 and the mark / space determination unit 32. Supply to. The line buffer 33 stores print data for four lines of past, present, and future print data. The data newly supplied from the shift register 30 and the data in the line buffer 33 are stored in the data updating unit 34.
Is added to the stored data, the oldest data is removed to update the data, and then the data is written in the line buffer 33. The energization time calculation unit 31 determines the energization time to the heating resistor corresponding to the print data of interest based on the data supplied from the shift register 30 and the line buffer 33, and supplies the energization time data to the thermal head drive circuit 12. The energization time is determined in advance from the positional relationship between the mark data and the space data around the print data of interest, or the ratio of the mark data and space data around the print data of interest to the predicted heat storage energy of the heating resistor corresponding to the print data of interest. The relationship of the determined energization times is tabulated and determined by referring to the stored ROM.
The characteristic of the determination of the energization time in this recording apparatus is that the energization time is determined not only for the mark dots forming an image but also for the space dots not forming an image. Therefore, the energization time calculation unit 31 is provided with a mark dot table and a space dot table. The selection of the table is executed by the output of the mark / space determination unit. In this way, by correcting the energization time for different heat storage energy in each heating resistor, the temperature of the recording material recording layer is kept within the clouding temperature range for mark dots and for space dots regardless of the image pattern. It could be controlled within the clearing temperature range.

In the above embodiments, the example in which the thermal head recording means is used as the energy applying means has been described, but the energy is not limited to the thermal head recording means, and the energy capable of modulating the output energy without departing from the subject of the present invention. As the applying means, other energy applying means can be used depending on the recording layer material.

In the embodiment, the recording or erasing energy is increased or decreased by changing the energization time, but the number of energization pulses or the recording voltage may be changed without being limited to this.

Further, the constitution of the arithmetic means is not limited to the embodiment, and other constitutions or energy applying means and the temperature of the recording material recording layer are changed without departing from the subject of the present invention. Calculation means for factors can be used.

In the above embodiments, the cloudy state is used as an image, but the cloudy state may be used as an initial state and the transparent state may be used as an image. Further, the recording layer material to which the present invention can be applied is not limited to the material of the embodiment, such as a recording material using a leuco dye as a color source that gives a reversible color tone change only by controlling thermal energy, or light energy. It can also be applied to a recording material capable of reversible state conversion only by controlling.

According to the present invention, recording and erasing of a visible image can be stably and reliably performed. Further, the image can be rewritten without erasing the already formed image in advance. Further, the image can be rewritten regardless of the image pattern or the pattern position. Furthermore, it has become possible to downsize and simplify the device. Recording and erasing can be performed in pixel units on any part of the recording material. In addition, resource saving of recording materials and reduction of printing cost have become possible.

[0027]

As described above, according to the recording medium processing apparatus of the present invention, recording and erasing on the recording medium can be surely performed.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording medium processing apparatus using a thermal head thermal recording unit that is an embodiment of the present invention.

FIG. 2 is a diagram showing recording and erasing of a visible image by the recording medium processing device of the present invention.

FIG. 3 is a configuration diagram of a recording material used in the recording medium processing apparatus of the present invention.

FIG. 4 is a diagram for explaining a driving operation of a heating element of a thermal head.

FIG. 5 is a diagram for explaining transition temperature ranges of both a cloudy state and a transparent state.

FIG. 6 is a diagram showing a change in white turbidity concentration with repeated white turbidity.

FIG. 7 is a diagram schematically showing heat distribution in the thickness direction of a recording medium when heat is applied by a thermal head.

FIG. 8 is a diagram for explaining a method of calculating recording or erasing energy.

FIG. 9 is a diagram showing a configuration of an energization time calculation circuit of a thermal head thermal recording unit.

[Explanation of symbols]

13 thermal head thermal recording means, 14 energization time calculation circuit, 25 recording medium, 26 heating resistor array, 27 already image, 31 energization time calculation unit

Claims (1)

Claim: What is claimed is: 1. A visible image is recorded by applying recording energy for recording a visible image, and erase energy is applied to erase the visible image. Generating means for generating recording information for recording the visible image on a recording medium from which data is erased, and a plurality of recordings in a recording unit of the recording information based on the recording information generated by the generating means. Generating means for generating a signal, and recording for recording the visible image by applying the recording energy to the recording medium a plurality of times within a recording unit of the recording information according to the recording signal generated by the generating means An apparatus for processing a recording medium, comprising: a means and an erasing means for applying erasing energy to the recording medium to erase the visible image recorded by the recording means.