JP2000312293A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print out image data whose resolution is not deteriorated from the resolution of original image data even when the resolution of image data sent from a printer controller section is higher than the resolution of image data processable by a printer engine. SOLUTION: The printer is provided with a clock generator that can generate a clock signal whose frequency is an integer multiple of a frequency of a clock signal used for normal print of a printer engine, a clock control section 22 that switches the frequency of the clock signal from the frequency for the normal print into a frequency that is an integer multiple of the frequency for the normal print, a density control signal 23 that applies density conversion to image data based on the timing of the clock signal with the frequency for the normal print and an integer multiple of the frequency for the normal print, and a memory control section 24 that controls processing of storing the image data density-converted based on the timing of the clock signal with the frequency for the normal print and an integer multiple of the frequency for the normal print to an image memory and processing of transmitting the data to a recording head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having a function of converting image data density.

[0002]

2. Description of the Related Art A conventional printer stores print data received from a host computer in an image memory, and prints the image data read from the image memory at a predetermined resolution by a printer engine and a recording head. I have. Further, in the conventional printer device, when the resolution of the received image data is different from the printable resolution, the host computer is notified that printing is not possible and the image data having the printable resolution is sent again. Needed. In order to solve such inconveniences, for example, Japanese Patent Laid-Open Publication No. Hei 5-96792 discloses that when printing low-resolution print data with a high-resolution printer, dot density is converted (resolution is converted). A printer device capable of printing a high-quality image by determining a scanning speed of a print head in accordance with image data whose resolution has been converted is shown. Also, Japanese Unexamined Patent Publication No. Hei 6-1131
Japanese Patent Application Laid-Open No. 21-213421 combines a process of converting the pixel density to enlarge and reduce in the main scanning direction and the sub-scanning direction with a process of performing enlargement and reduction in the seed scanning direction by changing a video clock in a printer interface. Accordingly, a printer device in which the enlargement / reduction processing when the image data is enlarged / reduced and printed is accelerated is shown. JP-A-5-96792 and JP-A-6-96792.
In the invention of JP-A-113121, a large amount of image memory and data conversion means are provided, the received image data is converted according to the resolution of the printer device, and then temporarily stored in the image memory. According to the printing.

[0003]

However, in a conventional printer device capable of printing by converting the resolution of image data, a large amount of image memory is required to print image data having a resolution different from that of the printer. Although it is necessary, and printing is enabled by the converted image data, the conversion has a problem that the printing dot configuration is changed and the resolution is lower than the resolution of the original image data. The present invention of claims 1 and 2
The present invention has been made in order to solve the conventional problems as described above, and the density of image data is converted by an engine controller, so that the resolution of image data that can be processed by the printer engine of the printer device is smaller than that of the printer controller. Even if the resolution of the image data transmitted from the printer unit is high, printing can be performed without degrading the resolution from the resolution of the original image data, and the image required for the resolution of the image data transmitted from the printer controller unit It is an object of the present invention to provide a printer device capable of printing even with an image memory having a smaller capacity than the memory capacity. The first and second aspects of the present invention are directed to a case where the resolution of the image data transmitted from the printer controller is higher than the resolution of the printer device. Even when the resolution is lower than the resolution of the apparatus, it is desired to print without deteriorating the resolution of the image data to be printed. According to the third aspect of the present invention, the resolution of the image data transmitted from the printer controller is made smaller than the resolution of the image data that can be processed by the printer engine of the printer by performing the density conversion of the image data by the engine controller. It is an object of the present invention to provide a printer capable of printing at a higher resolution than the resolution of the original image data even when the resolution is low.

[0004]

According to a first aspect of the present invention, there is provided a printer apparatus for controlling communication with a host apparatus and controlling the entire printer apparatus. An image memory for storing a print image, a recording head for printing on printing paper, a printer engine for performing a printing operation by operating at least the recording head, an engine controller for controlling the printer engine and the recording head, A printer device having a clock generator capable of generating a clock signal frequency that is an integral multiple of a clock signal frequency used during normal printing of the printer engine,
The engine controller unit communicates with the engine controller unit and the printer controller unit and controls the engine controller unit, and a clock signal used when transferring image data from the printer controller unit to the image memory. A clock control unit capable of switching the frequency from the frequency at the time of the normal printing to the frequency of the integral multiple, and, when transferring image data from the printer controller unit to the image memory, adapting the resolution of the transferred image data. A density conversion unit that performs density conversion of the image data based on the clock signal having the frequency at the time of the normal printing and the integer multiple of the frequency; Control of the process of transmitting the selected image data to the recording head A memory control unit that performs, based on the frequency and the integral multiple of the frequency of the clock signal at the time of normal printing, characterized in that it comprises a. The invention of claim 2 is
2. The printer device according to claim 1, wherein a storage capacity of the image memory is a capacity of a pixel corresponding to a clock signal having a frequency at the time of the normal printing, and the engine controller unit stores the density-converted image data. After storing in the image memory, the process of transmitting to the recording head based on the timing of the clock signal of the frequency of the normal printing is performed by the number of times corresponding to the integer value of the frequency obtained by multiplying the frequency of the normal printing by an integer. It is characterized in that it is implemented. According to a third aspect of the present invention, there is provided a printer device that controls communication with a host device and controls the entire printer device, an image memory that stores a print image, and performs printing on print paper. A clock signal used at the time of normal printing of the printer engine in a printer apparatus including a printhead, a printer engine that performs a printing operation by operating at least the printhead, and an engine controller that controls the printer engine and the printhead. A CPU that includes a clock generation device that can generate a clock signal frequency that is an integer fraction of the frequency, wherein the engine controller communicates with the engine controller and the printer controller and controls the engine controller; When,
A clock control unit that can switch the frequency of a clock signal used when transferring image data from the printer controller unit to the image memory from the frequency at the time of the normal printing to a frequency that is a fraction of the integer; and When transferring the image data to the memory, the density conversion of the image data is performed based on the clock signal of the frequency at the time of the normal printing and the frequency of the above-mentioned 1 / in accordance with the resolution of the transferred image data. The density conversion unit controls the process of storing the image data subjected to the density conversion in the image memory and the process of transmitting the image data stored in the image memory to the recording head by controlling the frequency at the time of the normal printing and the one-half of the integer. A memory control unit that performs the operation based on a clock signal of a frequency.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on illustrated embodiments. FIG. 1 is a block diagram showing a schematic overall configuration of a first embodiment of the printer device of the present invention. As shown in FIG. 1, the printer device 2 of the present embodiment
An interface (I / F) cable 3 is connected to a host computer 1 that outputs and processes image data.
Connected by Further, the printer device 2 includes a printer controller unit 11 which includes an engine controller unit 12 which will be described later and controls the overall operation of the printer device 2;
An engine controller unit 12 that controls the printer engine 14 to execute a printing operation, an image memory 13 that stores image data, a printer engine 14 that executes a printing operation, and a recording head 15 that prints an image on printing paper. Have. In the engine controller section 12,
A CPU 21 for controlling the engine controller 12 and communicating with the printer controller 11, a clock controller 22 for switching and controlling a video clock for transferring image data, and a density converter 23 for performing density conversion of image data And the density converted image data is stored in the image memory 13.
And a memory control unit 24 that controls transmission of image data from the image memory 13 to the recording head 15. Although not shown in FIG. 1, the clock generator used in this embodiment is a printer engine 14.
Is configured to be able to generate a clock signal frequency that is an integral multiple of the clock signal frequency used during normal printing.

In the printer device 2 of the present embodiment, for example, the printer engine 14 side has a maximum resolution of 6
It has a processing capacity only up to 00 dpi image data, and is transmitted from the host computer 1 to 1200 dpi (600 dpi 2
When the CPU 21 receives from the printer controller 11 a print command to transmit 1200 dpi image data from the printer controller 11,
The clock control unit 22 is controlled so as to transfer 00 dpi image data. The clock control unit 22 includes a CPU 21
, The video clock is switched for 1200 dpi. The printer controller 11 transmits the image data of 1200 dpi synchronized with the switched video clock to the engine controller 12. First, the density converter 23 of the engine controller 12
Only the odd-numbered data in the image data is held by using the video clock for 0 dpi, and the odd-numbered image data is transmitted to the memory control unit 24. Memory control unit 24
Stores the image data subjected to the density conversion (thinned out to 600 dpi) in the image memory 13 and stores the image data in the image memory 1 so as to be in time for the printing timing of the recording head 15.
3 sends 600 d of image data to the recording paper
pi image is formed. Next, the CPU 21 requests the printer controller 11 to retransmit the image data of the line on which the printing of the odd-numbered data has already been completed. The image data transmitted from the printer controller 11 is sent to the engine controller 12
This time, the density conversion unit 23 holds only the even-numbered image data, and transmits the even-numbered image data to the memory control unit 24. The memory control unit 24 stores the image data subjected to the density conversion (thinned out to 600 dpi) in the image memory 13 and transmits the image data from the image memory 13 so as to be in time for the print timing of the recording head 15. 600 dpi consisting only of even-numbered image data
Is formed. When forming an even-numbered 600 dpi image, the CPU 21 controls the print timing so that odd-numbered data in the 1200 dpi image starts printing from a position shifted by one dot.
pi image is formed.

FIG. 2 is an operation flowchart of the first embodiment. In the present embodiment, for example, it is assumed that the printer engine 14 can process only 600 dpi and 400 dpi image data. Step S1
In response to the print instruction from the host computer, the printer controller 11
, A print command (1200 dpi) is transmitted.
In step S2, the CP of the engine controller unit 12
U21 determines whether or not the image data has a resolution that can be processed by the printer engine 14 side.
(Step S2: Ye)
In step S3, the process proceeds to step S3. If the resolution cannot be processed by the printer engine 14 (step S2: N).
In step o), the process proceeds to step S4. In step S3, the printer engine 14 and the recording head 15 perform a normal printing operation. In step S4, the CPU 21 of the engine controller 12 causes the clock controller 22 to output 1200d.
Set pi image transfer. In step S5, the clock control unit 22 switches the video clock for 1200 dpi. In step S <b> 6, the printer controller 11 transmits the image data of 1200 dpi synchronized with the video clock to the engine controller 12.
In step S7, the density conversion unit 23 of the engine controller unit 12 holds the odd-numbered image data using a 600 dpi video clock having a frequency that is half the frequency of 1200 dpi, and converts the density of the image data into the memory control unit 24. Send In step S8, the memory control unit 2
4 stores the image data in the image memory 13. In step S9, the memory control unit 24 transmits the image data from the image memory 13 in time for the print timing of the recording head 15. In step S10, the recording head 1
Reference numeral 5 prints an odd number of image data at a scanning speed of 600 dpi. In step S11, the CPU 21 of the engine controller 12 requests the printer controller 11 to retransmit the image data of the line for which the printing of the odd-numbered data has been completed. In step S12, the printer controller section 11 transmits 1200 dpi image data synchronized with the video clock. In step S13, the engine controller 12
The density conversion unit 23 holds the even-numbered image data by a 600 dpi video clock having a frequency that is half the frequency of 1200 dpi, and transmits the density-converted image data to the memory control unit 24. In step S14, the memory control unit 24 stores the image data in the image memory 13.
In step S15, the memory control unit 24
The image data is transmitted from the image memory 13 in time for the printing timing of No. 5. In step S16, the recording head 15 performs even-numbered printing of image data at a scanning speed of 600 dpi. When forming an even-numbered 600 dpi image, the CPU 2 executes printing so that odd-numbered data in the 1200 dpi image starts printing from a position shifted by one dot.
1 controls the printing timing.

FIGS. 3 and 4 are diagrams showing the timing of density conversion by the video clock according to the first embodiment. FIG.
Is a timing chart in the case of holding the odd-numbered image data of 1200 dpi. Hereinafter, the operation will be described based on the timing chart of FIG. 3 and FIG. (1) The transfer request signal CRDY is asserted from the printer controller 11 in synchronization with the video clock VCLKO for 1200 dpi. (2) The engine controller 12 detects assertion of the CRDY signal and asserts the transfer permission signal ERDY. (3) The printer controller unit 11 transmits 1200 dpi image data VDATA (1200 dpi) after a certain number of clocks from the assertion of the ERDY signal. (4) Density converter 23 of engine controller 12
After counting the dummy clock set in the CPU 21, VDATA (1200 dpi) is
(1200 dpi). (5) Furthermore, the density conversion unit 23 converts VD (1200 dpi) into VCLK1 at VCLK1, which is half the frequency of VCLKO.
Density conversion is performed by holding D (600 dpi). (6) When the predetermined valid image data has been received, the engine controller 12 negates the ERDY signal. (7) Upon detecting negation of the ERDY signal, the printer controller 11 negates the CRDY signal. FIG. 4 is a timing chart when an even-numbered 1200 dpi image data is held. The operation of holding the even-numbered data in FIG. 4 may be basically the same as the operation of holding the odd-numbered data in FIG. 3, but the timing of holding the image data held in the image memory is changed to the odd-numbered data and the even-numbered data. ERDY under the control of the CPU 21 of the engine controller 12
By adjusting the signal assert timing and the number of dummy clocks used in the density converter 23, only the odd-numbered image data or only the even-numbered image data can be held in the image memory 13 by changing the holding timing. Like that. By configuring and operating as described above, the printer device 2 of the printer engine 14 having a resolution of 600 dpi has a resolution of 1200 dpi.
When the image data of i is received, an image of 1200 dpi can be formed. That is, when printing 1200 dpi image data with a 600 dpi printer device, the 600
Double the clock frequency for dpi (= 1200/600
Double) the clock frequency, print the odd-numbered data of the image data received at twice the frequency first, and then print the even-numbered data of the image data received again at the double frequency. By doing so, it is possible to print image data having a resolution twice as high as the resolution that can be printed by the printer device without deteriorating the resolution.

Here, for example, in order to print image data of triple resolution according to the present embodiment, the first image data of every third image data is firstly converted by using a triple clock frequency. Print, then print the second image data of every third image data, and finally print the third image data of every third image data Good. In this manner, image data having a resolution that is an integral multiple of the resolution that can be printed by the printer device can be printed without deteriorating the resolution. Also,
For example, in order to form an image of 1200 dpi, the capacity of the image memory 13 for pixels of 1200 dpi is normally required. Since printing is performed in batches, printing with a resolution of 1200 dpi can be executed with the capacity of the image memory 13 necessary for forming a half 600 dpi image. FIG. 5 shows a second embodiment of the present invention.
6 is an operation flowchart of the embodiment. The components of the second embodiment are the same as those of the first embodiment, but the operation of each component in the printer device 2 is changed. Next, in the printer device 2 of the second embodiment, FIG.
6 and the density conversion of the image data in the engine controller 12 as shown in FIG. 6, the resolution of the image data transmitted from the printer controller Even when the resolution is lower than the resolution, an image having a higher resolution than the original image data can be printed. In the present embodiment, the CPU 21 that controls the engine controller 12 and communicates with the printer controller 11 is provided by the CPU 21.
When receiving a print command from the CPU 1, the CPU 21 sets image transfer to the clock control unit 22. For example, when the printer engine 14 has a processing capability only up to 400 dpi image data as the lowest resolution, and the CPU 21 receives a command that the printer controller 11 transmits 200 dpi image data to the engine controller 12, the CPU 21 200 for the control unit 22
Make settings for dpi image transfer. The clock control unit 22
The video clock is set to 200 according to the setting by the CPU 21.
Switch for dpi. Printer controller 11
Transmits 200 dpi image data synchronized with the video clock. The density conversion section 23 of the engine controller section 12 uses a video clock for 400 dpi to output 20
The image data of 0 dpi is held twice for each pixel and transmitted to the memory control unit 24 as image data of 400 dpi.
The memory control unit 24 stores the image data subjected to the density conversion (expanded to 400 dpi) in the image memory 13 and transmits the image data from the image memory 13 in time for the print timing of the recording head 15. In this manner, a high-resolution 400 dpi image can be printed from the original 200 dpi image data.

FIG. 5 is an operation flowchart of the second embodiment. In the present embodiment, for example, it is assumed that the printer engine 14 can process only 600 dpi and 400 dpi image data. Step S2
In FIG. 1, the printer controller 11 responds to a print instruction from the host computer, and the engine controller 1
2 is sent a print command (200 dpi).
In step S22, C of the engine controller unit 12
The PU 21 determines whether or not the image data has a resolution that can be processed by the printer engine 14 side.
4 (step S22:
If yes, the process proceeds to step S23, and if the resolution cannot be processed by the printer engine 14 (step S2).
2: No), the process proceeds to step S24. Step S23
Then, the printer engine 14 and the recording head 15 perform a normal printing operation. In step S24, the CPU 21 of the engine controller 12
The user sets 200 dpi image transfer. Step S25
Then, the clock control unit 22 sets the video clock to 200
Switch for dpi. In step S26, the printer controller unit 11 outputs the 20
The image data of 0 dpi is transmitted to the engine controller 12. In step S27, the density conversion unit 23 of the engine controller unit 12 holds each pixel of the image data twice by using a video clock for 400 dpi at twice the frequency for 200 dpi, and converts the density of the image data to the memory control unit 24. Send data. In step S28,
The memory control unit 24 stores the image data in the image memory 13. In step S29, the memory control unit 24 transmits image data from the image memory 13 in time for the print timing of the recording head 15. In step S30, the recording head 15 prints image data at a scanning speed of 400 dpi.

FIG. 6 is a timing chart showing the timing of density conversion by the video clock according to the second embodiment, in which 200 dpi image data is held twice for each pixel. Hereinafter, the operation will be described based on the timing chart of FIG. 6 and FIG. (1) The transfer request signal CRDY is asserted from the printer controller 11 in synchronization with the video clock VCLKO for 200 dpi. (2) The engine controller 12 detects assertion of the CRDY signal and asserts the transfer permission signal ERDY. (3) The printer controller 11 transmits 200 dpi image data VDATA (200 dpi) after a certain number of clocks from the assertion of the ERDY signal. (4) Density converter 23 of engine controller 12
After counting the dummy clock set in the CPU 21, VDATA (200 dpi) is
D (200 dpi). (5) Further, the density conversion unit 23 converts VD (200 dpi) into VD with VCLK1 which is twice the frequency of VCLK0.
(400 dpi) to perform density conversion. (6) When the predetermined valid image data has been received, the engine controller 12 negates the ERDY signal. (7) Upon detecting negation of the ERDY signal, the printer controller 11 negates the CRDY signal.

With the above-described configuration and operation, for example, in the printer device 2 of the printer engine 14 having a resolution of 400 dpi or more,
When image data of dpi is received, an image of 400 dpi can be formed. That is, when image data of 200 dpi is printed by a printer of 400 dpi, 400 image data used in normal printing by the printer is used.
The clock frequency for dpi is 1/2 times (= 200/40
(0x) clock frequency, and prints the image data received at a half frequency thereof while holding each pixel of the image data twice by using a 400 dpi video clock. Image data having a resolution that is 倍 of the resolution that can be printed by the printer can be printed with an improved resolution. here,
For example, in order to print image data having a 1/3 resolution according to the present embodiment, printing is performed such that each pixel of the image data is held and printed three times using a 1/3 clock frequency. do it. In this way, it is possible to print image data having a resolution that is a fraction of the resolution that can be printed by the printer device while improving the resolution.

[0013]

As described above, according to the first and second aspects of the present invention, the resolution of the image data that can be processed by the printer engine of the printer device is improved by performing the density conversion of the image data by the engine controller. Even if the resolution of the image data transmitted from the printer controller is high, printing can be performed without deteriorating the resolution from the resolution of the original image data, and the resolution required for the image data transmitted from the printer controller is required. Even if the image memory has a smaller capacity than the capacity of the image memory, printing can be performed, and a high-resolution image can be formed. Therefore, manufacturing cost when manufacturing the printer device can be reduced.
According to the third aspect of the present invention, the resolution of the image data transmitted from the printer controller is made smaller than the resolution of the image data that can be processed by the printer engine of the printer device by performing the density conversion of the image data by the engine controller. Even if it is low, printing can be performed at a resolution higher than the resolution of the original image data.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic overall configuration of a first embodiment of a printer device of the present invention.

FIG. 2 is an operation flowchart of the first embodiment.

FIG. 3 is a timing chart when an odd-numbered 1200 dpi image data according to the first embodiment is held.

FIG. 4 is a timing chart in the case of holding an even-numbered 1200 dpi image data according to the first embodiment.

FIG. 5 is an operation flowchart of the second embodiment.

FIG. 6 is a timing chart when 200 dpi image data according to the second embodiment is held twice for each pixel.

[Explanation of symbols]

1. Host computer, 2. Printer device,
3 ... I / F cable, 11 ... Printer controller, 12 ... Engine controller, 13 ...
・ Image memory, 14 ・ ・ ・ Printer engine, 15 ・ ・
-Recording head, 21 ... CPU, 22 ... clock control unit, 23 ... density conversion unit, 24 ... memory control unit

Claims (3)

[Claims] A printer controller for controlling communication with a host device and controlling the entire printer device; an image memory for storing a print image; a recording head for printing on print paper; In a printer device having a printer engine that performs a printing operation by operating a recording head, and an engine controller that controls the printer engine and the recording head, a clock that is an integral multiple of a clock signal frequency used during normal printing by the printer engine A clock generation device capable of generating a signal frequency, wherein the engine controller communicates with the engine controller and the printer controller, and controls the engine controller. Image de A clock control unit that can switch the frequency of the clock signal used when transferring the data from the frequency during the normal printing to the integer multiple of the frequency, when transferring image data from the printer controller unit to the image memory, A density conversion unit that performs density conversion of the image data based on a clock signal of the frequency at the time of the normal printing and the frequency of the integer multiple in accordance with the resolution of the image data to be transferred, and converts the density-converted image data. A memory control unit that controls the process of storing the image data and the process of transmitting the image data stored in the image memory to the recording head based on the clock signal of the normal printing frequency and the integer multiple of the frequency. A printer device comprising: 2. A storage capacity of the image memory is a capacity of a pixel corresponding to a clock signal of a frequency at the time of the normal printing, and the engine controller stores density-converted image data in the image memory. The process of transmitting to the recording head later based on the timing of the clock signal of the normal printing frequency is performed a number of times corresponding to the integer value of the frequency obtained by multiplying the normal printing frequency by an integer. 2. The printer device according to claim 1, wherein: 3. A printer controller for controlling communication with a host device and controlling the entire printer device, an image memory for storing a print image, a recording head for printing on print paper, and In a printer device having a printer engine that performs a printing operation by operating a recording head, and an engine controller that controls the printer engine and the recording head, the printer engine includes: A clock generation device capable of generating a clock signal frequency of the above, wherein the engine controller communicates with the engine controller and the printer controller and controls the engine controller. Image in image memory A clock control unit capable of switching a frequency of a clock signal used for transferring data from the frequency at the time of the normal printing to a frequency that is a fraction of the integer, and a method of transferring image data from a printer controller to an image memory. A density conversion unit that performs density conversion of the image data based on a clock signal having a frequency at the time of the normal printing and a frequency that is a fraction of the integer, adapted to a resolution of the image data to be transferred; The process of storing the image data stored in the image memory and the process of transmitting the image data stored in the image memory to the recording head are controlled based on the normal printing frequency and the clock signal having a frequency that is a fraction of the integer. A printer device comprising: a memory control unit.