Incremental printing of symbolic information – Thermal marking apparatus or processes – Preheating
Reexamination Certificate
1999-03-19
2001-10-02
Le, N. (Department: 2861)
Incremental printing of symbolic information
Thermal marking apparatus or processes
Preheating
Reexamination Certificate
active
06297841
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thermosensitive recording method and thermosensitive recording apparatus and in particular, to a thermosenstivie recording method and thermosensitive recording apparatus in which a recording condition is changed according to a temperature of a recording device.
2. Description of the Related Art
Conventionally, this type of photosensitive recording method and apparatus have been used for reducing a recording time while maintaining a sufficient print concentration such as a character and a symbol on a recording paper. Moreover, a technique utilizing a recording device temperature is disclosed, for example, in Japanese Patent Publication (unexamined) A-5-268436 and A-3-297687, in which a recording device temperature is automatically supplied to a register so that the register can be read when required, thus enabling to reduce the CPU load. Japanese Patent Publication (unexamined) A-62-193851, in which thermosensitive recording apparatus having sift resistor to control ON/OFF of drive device. Object of this related art is reduction of energy consumption.
FIG. 4
is a block diagram showing this conventional photosensitive recording apparatus that comprises: a recording device
42
for printing on a recording paper with a print energy generated when a voltage is applied; a temperature sensor
43
for detecting a temperature of the recording device
42
; a cutter for cutting the recording paper; a drive block
44
for feeding the recording paper; a position sensor for detecting a leading edge of the recording paper; and a recording controller
41
which operates as follows. That is, upon reception of a record start command, the record controller
41
checks the temperature shown by the temperature sensor
43
.
If the check result is equal to or above a predetermined temperature (for example, 25 degrees C.), the record controller
42
sets a predetermined normal speed (for example V=13 mm/sec) as the recording paper feed speed during a recording operation for printing on the recording paper, and a predetermined normal print energy as the print energy of the recording device
42
. For example, the normal print energy is such that when a printing is performed at the normal recording paper feed speed with the recording device
42
at a temperature of 25 degrees C., or above, it is possible to obtain a sufficient print concentration as a black ratio representing a ratio of a print area occupied by black.
Moreover, if the aforementioned check result is below 25 degrees C., in order to obtain a predetermined black ratio or above, the recording paper feed speed is set lower than the normal speed during a recording operation and the print energy of the recording device
42
is set to the normal print energy; or the recording paper feed speed is maintained at the normal speed and the print energy of the recording device
42
is set higher than the normal print energy.
Next, explanation will be given on the operation of the conventional photosensitive recording apparatus.
The record controller
41
, upon reception of a record start command, checks the temperature indicated by the temperature sensor
43
and stores the temperature value. Next, the record controller
41
performs a roll-back operation. That is, the recording paper which has been waiting with its leading edge at a wait position
47
is rolled back to a record start position
48
by a drive block
44
.
If the check result stored is equal to or above 25 degrees C., the record controller
41
causes the drive block
44
to feed the recording paper at a normal speed and supplies to a recording device
42
a printing pulse indicating a printing period (print energy generation period) from a print start to a print end. The printing device
42
is made to print on the printing paper with a normal print energy. In this case, the printing state is equal to or above a predetermined black ratio and brings about a sufficient print concentration.
Moreover, if the check result stored is below 25 degrees C., in order to obtain a print state of sufficient print concentration equal to or above the predetermined black ratio, the drive block
44
is operated so as to feed the recording paper at a lower speed than the normal speed while the recording device
42
prints on the printing paper with the normal print energy, or the drive block
44
is operated so as to feed the recording paper at the normal speed while the print pulse is supplied to the recording device
42
so as to print on the recording paper with a higher print energy than the normal print energy.
In the aforementioned thermosensitive recording apparatus, when the recording device temperature is below 25 degrees C., in order to obtain a print state equal to or above a predetermined black ratio, there is a necessity to slow down the print speed (recording paper feed speed) or increase the recording device print energy.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a thermosensitive recording method and apparatus capable of obtaining a sufficient print concentration of characters and symbols with a sufficient black ratio without lowering the print speed (recording paper feed speed) or increasing the recording device print energy in many circumstances even when the recording device temperature is below 25 degrees C.
In order to achieve the aforementioned object, in the thermosensitive recording method according to the present invention, a recording device is warmed up prior to a recording. That is, while a recording paper is rolled back at a predetermined feed speed prior to recording, a predetermined print energy is applied to the recording device to perform a pseudo-printing, i.e., a printing operation not causing a black point on the recording paper.
The thermosensitive recording apparatus according to the present invention comprises:
a recording device for printing on a recording paper with a predetermined print energy;
a temperature sensor for detecting a temperature of the recording device;
a drive block for feeding the recording paper; and
a recording controller which upon reception of a predetermined command, checks a temperature indicated by the temperature sensor so as to decide according to a result of the check whether to perform a warm up of the recording device while the recording paper is rolled up from a wait position to a recording start position, and to determine a feed speed of the recording paper and a print energy to be applied to the recording device during a printing.
Furthermore, the recording controller controls the apparatus as follows:
if the temperature of the recording device is equal to or above a first threshold, then the warm up is not performed, the feed speed of the recording paper is set to a first speed, and the print energy to be applied to the recording device is set to a first print energy;
if the temperature of the recording device is below the first threshold value and above or equal to a second threshold value, then the warm up is performed, the feed speed is set to the first speed, and the print energy is set to the first print energy; and
if the temperature of the recording device is below the second threshold value, then the warm up is performed, and the feed speed is set to a second speed lower than the first speed in combination with setting of the first print energy, or the feed speed is set to the first speed in combination with setting of a second print energy higher than the first print energy.
Moreover, in the thermosensitive recording apparatus according to the present invention, the warm up operation is performed by applying a predetermined third print energy to the recording device to perform a pseudo-printing without causing a black point on the recording paper while the recording paper is rolled back at a predetermined third speed.
REFERENCES:
patent: 0409201 (1991-01-01), None
patent: 54-53546 (1979-04-01), None
patent: 62-135382 (1987-06-01), None
patent: 62193851 (1987-08-01), None
patent: 6
Feggins K.
Le N.
NEC Corporation
Ostrolenk Faber Gerb & Soffen, LLP
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