JP2005059422A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer that unerringly removes noise by means of a simple structure. <P>SOLUTION: A line memory 44 stores the gradation value of image data for one line to print. A head driving section 45 applies a voltage to heating elements 51a to 51n in accordance with the gradation value stored in the line memory 44. A negational sound data generation section 47 totals gradation values stored in the line memory 44 and estimates printing noise generated during printing by applying to LUT 48. Negational sound data, in which the phase of the printing noise estimated is reversed, is generated and outputted to a speaker control section 37 in synchronization with the application of a voltage to the heating elements 51a to 51n. Consequently, a noise negating sound is reproduced from the speaker 7 at the same time as the occurrence of printing noise by printing and removes the printing noise. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a printer having a print head that is driven in accordance with image data that determines gradation for each pixel, and that performs printing while relatively moving the print head and recording paper.

  There is known a color thermal printer that presses a thermal head against color thermal recording paper and records an image by heating. As is well known, the thermal head includes a heating element array in which heating elements are arranged in a line, and records an image in a line. Each heating element is driven according to the density of each pixel. An image for one screen is obtained by performing printing while relatively moving the thermal head and the color thermal recording paper.

  At the time of printing, printing noise is generated by driving each heating element. The print noise is intermittently generated according to the energization timing of the thermal head, and changes according to the print density, that is, the print energy generated by the heating element array. In order to remove such printing noise, use of an active type noise removing device (for example, see Patent Document 1 below) has been studied.

  The noise removing device described in Patent Document 1 collects generated noise with a microphone, and removes noise by generating a sound (canceling sound) in which the phase of the collected noise is inverted from a speaker. According to this noise removing device, it is possible to generate a canceling sound according to the noise collected in real time by the microphone, so that it is possible to effectively remove the printing noise that changes according to the printing density.

JP-A-6-230790

  However, in the apparatus described in Patent Document 1, in order to sample the generated noise and generate a canceling sound based on the sampled noise, in addition to the sampling microphone, the sampled analog audio signal is once converted into a digital signal. An A / D converter is required. For this reason, there existed a problem that component cost would increase.

  An object of the present invention is to provide a printer capable of performing active noise removal at low cost.

  In order to achieve the above object, a printer according to the present invention estimates a noise generated during printing based on image data, generates an audio signal having a phase opposite to the estimated noise, and the audio signal. And a speaker that actively removes noise by reproducing and outputting in synchronization with the timing of printing. The speaker may be used for audio reproduction of music and moving images.

  Since the printer according to the present invention estimates noise generated when printing image data based on the image data to be printed, it is not necessary to collect the generated noise. For this reason, since the apparatus can be simplified, the cost can be reduced and the apparatus can be downsized. In addition, it is possible to perform audio reproduction of music and moving images using a speaker that reproduces noise canceling sound.

  FIG. 1A is an external view of a color thermal printer embodying the present invention. FIG. 2B is an explanatory diagram showing the inside of the printer case. The color thermal printer 1 is provided with a printer case 3 that forms the outline thereof. A paper discharge port 3a is formed on the front surface of the printer case 3, and the sound generation unit 5a constituting the speaker 5 is exposed from both sides thereof. On the upper surface 2 of the printer case 3, an operation unit 6 on which a mode selection button, a music playback button, a print button, and the like are arranged, a memory in which a memory card 7 (see FIG. 2) storing image data and music data is loaded. A card slot 8 and a liquid crystal monitor 9 for performing various displays are provided.

  Inside the printer case 3 is set a recording paper roll 13 in which a long roll paper 11 (hereinafter referred to as recording paper) is wound in a roll form. A paper feed roller 15, a thermal head 17, a transport roller pair 19, and an optical fixing device 23 are provided in this order from the recording paper roll 13 side (upstream side).

  The color thermal printer 1 has a print mode and a music reproduction mode, and these modes can be switched by operating the operation unit 6. The color thermal printer 1 is used while switching between a print mode and a music reproduction mode. In the print mode, image data can be printed on the recording paper 11. The speaker 5 is used for reproducing cancellation sound data to be described later in the print mode, and is used for reproducing music data stored in the memory card 7 in the music reproduction mode.

  The speaker 5 is disposed in the vicinity of both sides of the recording paper 11 on the downstream side of the optical fixing unit 23. Since the optical fixing device 23 is formed wider than the recording paper 11, a dead space is generated on both sides of the recording paper 11 on the downstream side of the optical fixing device 23. However, in the color thermal printer 1, this dead space is generated. By arranging the speakers 5 in the space, the space is effectively utilized.

  As shown in FIG. 2, a CPU 31 is provided inside the color thermal printer 1. The CPU 31 is connected to each unit of the color thermal printer 1 and controls the operation of each unit based on an operation signal input from the operation unit 6. The CPU 31 outputs the music data stored in the memory card 7 to the speaker control unit 37 when the color thermal printer 1 is set in the sound reproduction mode, and stores it in the memory card 7 when set in the print mode. The processed image data is output to the print control unit 41.

  A speaker 5 is connected to the speaker control unit 37. The speaker control unit 37 incorporates a known amplifier circuit, amplifies the input audio signal, and outputs it to the D / A converter 38. The D / A converter 38 converts the digital audio data into analog audio data and outputs the analog audio data to the speaker 5. As a result, the audio data stored in the memory card 7 is reproduced from the speaker 5.

  The print controller 41 is provided with a frame memory 43, and image data output from the CPU 31 is stored in the frame memory 43. The print control unit 41 is connected with a paper feed roller 15, a conveyance roller pair 19, a thermal head 17, and an optical fixing device 23. The print control unit 41 drives these to print the image stored in the frame memory 43 on the recording paper 11.

  As is well known, the recording paper 11 has a heat-sensitive coloring layer of cyan, magenta, and yellow sequentially provided on a support. The yellow thermosensitive coloring layer, which is the uppermost layer, has the highest thermal sensitivity and develops yellow with a small amount of heat energy. The cyan thermosensitive coloring layer, which is the lowermost layer, has the lowest thermal sensitivity and develops cyan with large heat energy.

  The yellow thermosensitive coloring layer and the magenta thermosensitive coloring layer each have a light fixing property by light in a specific wavelength range, and the yellow thermosensitive coloring layer is blue-violet light having a peak wavelength of about 420 nm. When the yellow fixing light is irradiated, the coloring ability is lost. The magenta thermosensitive coloring layer loses its coloring ability when irradiated with magenta fixing light which is near ultraviolet light having a peak wavelength of around 365 nm.

  The paper feed roller 15 contacts and rotates the recording paper roll 13, pulls out the leading end of the recording paper 11 from the recording paper roll 13, and feeds it to the conveyance path. The conveying roller pair 19 nips the fed recording paper 11 and conveys it in the A direction from the upstream side to the downstream side and in the B direction from the downstream side to the upstream side. The transport roller pair 19 is driven by a transport motor (not shown) together with the paper feed roller 15. As the transport motor, for example, a pulse motor whose amount of rotation is determined according to the number of applied drive pulses is used. The print controller 41 controls the transport amount of the recording paper 11 in the A direction and the B direction by counting up and down the drive pulse.

  During the conveyance of the recording paper 11, thermal recording by the thermal head 17 and optical fixing by the optical fixing device 23 are performed. The optical fixing unit 23 includes a yellow fixing lamp 23y that emits yellow fixing light, a magenta fixing lamp 23m that emits magenta fixing light, and a reflector. The yellow fixing lamp 23y irradiates the yellow thermosensitive coloring layer on which the yellow image has been thermally recorded with the yellow fixing light to fix the yellow image. The magenta fixing lamp 23m irradiates the magenta thermosensitive coloring layer on which the magenta image has been recorded with the magenta fixing light to fix the light. The reflector reflects light emitted from the fixing lamps 23 y and 23 m for yellow and magenta toward the recording paper 11.

  The thermal head 17 heat-records each color image of yellow, magenta, and cyan by contacting the recording paper 11 and heating each thermosensitive coloring layer. A platen roller 18 that supports the recording paper 11 that receives pressure from the thermal head 17 from the back surface is provided at a position facing the thermal head 17. The recording paper 11 is thermally recorded with being sandwiched between the thermal head 17 and the platen roller 18. After thermal recording and optical fixing are performed, the recorded portion of the recording paper 11 is cut by a cutter (not shown) and discharged from the discharge outlet 3a.

  FIG. 3 shows an electrical configuration diagram of the thermal head 17 and the print control unit 41. The thermal head 17 is provided with a heating element array 51 in which a large number of heating elements 51 a to 51 n are arranged in the width direction of the recording paper 11. Resistive elements are used as the heating elements 51 a to 51 n, and generate thermal energy corresponding to the applied voltage and transmit it to the recording paper 11. Each of the heating elements 51 a to 51 n is connected to the print control unit 41. The print control unit 41 includes a frame memory 43, a line memory 44, a head drive unit 45, and a cancellation sound data generation unit 47.

  The frame memory 43 temporarily stores image data read from the memory card 7. One line of image data is read from the frame memory 43 and written to the line memory 44. The image data is a set of data for each pixel having color information for specifying a color and gradation values expressing the density of the color.

  The head drive unit 45 determines the drive voltage value of each of the heating elements 51a to 51n based on the image data for one line written in the line memory 44, and transmits the determined voltage to each of the heating elements 51a to 51n. Apply to. As a result, an image for one line is printed.

  Since printing noise is generated at the time of printing, a canceling sound data voice generation unit 47 is provided to remove this noise. The cancellation sound data generation unit 47 removes the printing noise based on the principle that the printing noise changes according to the gradation value of the image data to be printed.

  The canceling sound data generating unit 47 is provided with an LUT 48 for storing a noise data table. The noise data table includes a plurality of gradation values and predicted print noise data corresponding to the plurality of gradation values. Since the gradation value varies from pixel to pixel, for example, the sum of the gradation values of pixels for one line is used. Of course, an average value of pixels for one line may be used. Predictive print noise data corresponding to a plurality of gradation values is obtained based on print noise sampled in advance from an actual machine at the time of design. The predicted printing noise data and each gradation value are associated with each other and tabulated.

  The cancellation sound data generation unit 47 refers to the LUT 48 and extracts predicted print noise data corresponding to the total gradation value for one line written in the line memory 44. Then, by canceling the phase of the extracted predicted print noise data, cancel sound data for canceling the actually generated print noise is generated.

  This cancellation sound data is sent to the speaker control unit 37. The speaker control unit 37 drives the speaker 5 in synchronization with the print timing of the thermal head 17 based on the transmitted cancellation sound data. Thereby, the canceling sound is reproduced from the speaker 5. This canceling sound overlaps with the print noise, and the print noise is removed.

  When printing for one line by the thermal head 17 is completed, the conveyance roller pair 19 rotates and the recording paper 11 is conveyed for one line. The print control unit 41 generates canceling sound data corresponding to an image to be printed every time one line is printed. Thereafter, similarly, the second and subsequent prints and the canceling sound data are reproduced in synchronization with the prints.

  The operation of the present invention having the above configuration will be described below. When the user wants to view music with the color thermal printer 1, the user operates the mode selection button to match the music playback mode, inserts the memory card 7 storing the music data to be viewed into the memory card slot 8, and plays music. Press the play button. Thereby, music is reproduced from the speaker 5.

  On the other hand, when printing with the color thermal printer 1, the user sets the color thermal printer 1 in the print mode and inserts the memory card 7 storing the image data to be printed into the memory card slot 8. Then, the print button is pressed.

  When the print button is pressed, the image data stored in the memory card 7 is printed on the recording paper 11 line by line. Printing is performed from a yellow image. The print control unit 41 determines the voltage value to be applied to each of the heating elements 51a to 51n of the thermal head 17 based on the gradation value of the yellow image for one line. Thereafter, a voltage is applied simultaneously to each of the heating elements 51a to 51n, and a yellow image for one line is printed.

  At this time, the print control unit 41 estimates and removes printing noise generated during printing. The LUT 48 stores a noise data table in which a plurality of gradation values and predicted print noise data corresponding to the plurality of gradation values are associated with each other. Predictive print noise data is obtained from print noise sampled in advance by an actual machine. The print control unit 41 refers to the noise data table, and obtains predicted printing noise data based on the gradation value of the yellow image for one line to be printed.

  Then, the print control unit 41 generates canceling sound data that is a sound having an opposite phase to the obtained predicted printing noise data. This canceling sound data is reproduced from the speaker 5 in synchronism with the timing of voltage application to the heating elements 51a to 51n. As a result, the print noise generated during printing and the canceling sound data overlap each other and cancel each other, so that the print noise is removed.

  Similarly, yellow images from the second line are sequentially printed while removing printing noise. When the printing of the yellow image of all lines is completed, the yellow heat-sensitive coloring layer of the recording paper 11 is light-fixed by the light fixing unit 23. After light fixing of the yellow image, printing of the magenta image, light fixing of the magenta thermosensitive coloring layer, and printing of the cyan image are sequentially performed. When printing a magenta image and a cyan image, as in the case of printing a yellow image, print noise data is generated by estimating print noise for each line, and the cancel sound is synchronized with the print of this line. Printing noise is removed by reproducing the data.

  In this way, the printing noise sampled in advance is stored, and a canceling sound is generated and output based on the printing noise. Therefore, a noise sampling microphone or a sampled analog signal is converted into a digital signal. An A / D converter becomes unnecessary. Of course, the present invention requires a canceling sound data generation unit unlike the conventional one, which can be realized by rearranging the program of the data processor or the like. Components such as a microphone and an A / D converter are provided. Compared with the case of adding, the cost increase is small.

  In the above embodiment, a color thermal printer has been described as an example. However, the present invention is not limited to a color thermal printer, and is applied to, for example, an inkjet printer that prints an image by ejecting ink onto recording paper. It is also possible. FIG. 4 shows an ink jet printer embodying the present invention. In FIG. 4, the same members as those in the above-described embodiment are denoted by the same reference numerals.

  As is well known, the ink jet printer 100 includes a carriage 102 that reciprocates in the width direction of the recording paper 101. An ink cartridge 103 is detachably attached to the carriage 102. The ink cartridge 103 is provided with a head at a position facing the recording surface. The ink cartridge 103 includes, for example, tanks that store ink of four colors of yellow, magenta, cyan, and black, and a head is provided for each color. Printing is performed by ejecting ink from each head onto the recording paper 101 while the ink cartridge 103 reciprocates in the width direction of the recording paper 101.

  As with the color thermal printer described above, the inkjet printer 100 stores a predicted noise pattern for one line in the LUT for each gradation, and generates a noise pattern corresponding to the gradation of the line to be printed from the LUT. Read out and generate cancellation sound data. The canceling sound data is reproduced from the speaker 110 in synchronization with the print. Thereby, printing noise can be removed.

  In addition, an inkjet printer tends to have a larger dead space in the main body than a color thermal printer, so that it is more effective than a color thermal printer in terms of effective use of space. This is because, as shown in FIG. 4B, the head of the ink cartridge 103 must be moved to both ends of the recording paper 101, so that the ink cartridge 103 is retracted to the side of the recording paper 101. A evacuation space must be secured. For this reason, since the horizontal width of the main body is increased, a large dead space is generated before and after the evacuation space.

  As described above, even in a color thermal printer, the optical fixing device and the thermal head need to be slightly larger than the width of the recording paper. The dead space generated in the ink jet printer is larger than the space. Moreover, in recent inkjet printers, the number of ink colors has been increasing due to the demand for higher image quality, and accordingly, the size of the ink cartridge has become larger and the dead space tends to become larger. Since the speaker 110 is disposed in front of the evacuation space, the dead space can be effectively utilized.

  In addition to the printing noise described in the above-described embodiment, the noise generated during printing includes, for example, conveyance noise that occurs along with the conveyance of recording paper. In the present invention, it is also possible to remove this conveyance noise. That is, the carrier noise can be removed by obtaining the expected carrier noise in advance and outputting a canceling sound in which the phase of the predicted sound is inverted.

  The present invention can also be applied to a thermal transfer printer that uses an ink sheet in which an ink layer is provided and heats the back surface of the ink sheet with a thermal head to melt or soften the ink layer and transfer it to a recording paper. . Further, although a printer that prints a color image has been described as an example, it may be implemented in a monochrome printer that prints a monochrome image.

It is explanatory drawing showing the external appearance and internal structure of a color thermal printer. It is a block diagram of a color thermal printer. It is an electrical block diagram of a print control part and a thermal head. It is explanatory drawing showing an inkjet printer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color thermal printer 5 Speaker 6 Operation part 7 Memory card 8 Memory card slot 11 Recording paper 37 Speaker control part 41 Print control part 47 Canceling sound data generation part 48 Noise data table 100 Inkjet printer 101 Ink cartridge 105 Ink head

Claims (2)

In a printer that has a print head that is driven according to image data that determines the gradation for each pixel, and that performs printing while relatively moving the print head and recording paper,
Based on the image data, the noise generated during the printing is estimated, and an audio signal generation unit that generates an audio signal having a phase opposite to the estimated noise;
A printer comprising: a speaker that actively removes the noise by reproducing and outputting the audio signal in synchronization with the timing of printing.   The printer according to claim 1, wherein the speaker is also used for audio reproduction of music and moving images.

Images