JPH0324360Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a color printer for a computer that prints a color image displayed on a computer display.

Recently, color printers using the inkjet method, thermal transfer method, and color ribbon method have been developed one after another, and the color printers of personal computers
It is now possible to make color copies of CRT screens as they are.

Conventionally, in order to output CRT images to this type of color printer, video information including colors written in V-RAM (video ram) on the computer side is sequentially transferred to buffer memory, and then transferred via the Centronics interface. It was being transferred to the color printer.

However, this method has the disadvantage that the above program must be created for each target computer, and that connection with the CRT image display program must be considered. Furthermore, depending on the computer, the V-RAM for CRT display may be divided into two screens, RAM for the text screen and RAM for the graphics screen, in which case it is very difficult to create a screen copy program. It was a hassle. Another drawback is that when the screen changes from moment to moment and the program cannot be interrupted, the necessary screen cannot be copied immediately.

The present invention provides a color printer for a computer that eliminates the above-mentioned conventional drawbacks, and is composed of a video signal input interface section for inputting video information including colors displayed on a computer display; , comprising a video memory section that stores the video information input through the video signal input interface section, and a printer control section that outputs the video information stored in the video memory section to the printer mechanism section. It is something.

Next, the present invention will be explained with reference to embodiments shown in the drawings.

FIG. 1 is a block diagram of computer peripheral connections using a color printer, which is an embodiment of the present invention.

1 is a computer, 2 is a video signal interface connector for CRT, 3 is a video signal cable for CRT, 4 is a CRT video signal interface connector, 5 is a CRT display device, 6 is a Centronics interface connector for printer, 7 is Centronics Interface
Cable, 8 is a Centronics interface connector attached to the printer, 13 is the printer, 10 is a video signal interface connector attached to the printer, 12 is an operation-related panel and printer mechanism related to printing out images. be.

9 is a video signal input interface section, and 11 is a video memory section for storing video information input from the interface section.

The computer 1 constantly outputs a video signal to the CRT display device 5 to produce one image at a cycle of approximately 60 images/second.

The printer of the present invention is characterized in that this video signal is taken in through a video signal interface connector 10 and a video signal input interface 9. That is, the video signal branched from the video signal output cable 3 to the CRT display device 5 enters the video signal input interface section 9 via the interface connector 10.

Next, the video information is stored in the video memory section 11 under the control of various circuits as will be described later. In the present invention, by inputting an image printout command, the image displayed on the CRT display device 5 can be printed out on the paper loaded in the printer 13 of the present invention.

FIG. 2 is a more detailed block diagram of the color printer according to the present invention. In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals.

The video signal input through the video signal interface connector 10 is first sent to the synchronization-related control device 2.
6 and enters the video signal synchronization selection gate 27. The synchronization-related control device 26 receives a synchronization signal among the display video signals, and generates a pixel sample signal in synchronization with both the synchronization signal and the command from the general control block 16.

The synchronization-related control device 26 is connected to the general control block 16.
When a video signal capture command is input from the synchronization-related control device 26, the video signal synchronization selection gate 27 is opened and the video signal is captured. General control block 16
Also issued is a command indicating the image range to be printed, which command passes through the synchronization control unit 26 to the image range generator 24. Based on the command, the image range generator 24 calculates the start and end points of the image range on the video signal (the first and last scan lines, and the start and end points of each scan line in between), and generates an image for that period of time. Open the range selection gate 25.

In this way, only the video signal of the image range to be printed is taken into the pixel extraction gate 23, and the pixel extraction gate 23 extracts video bright spot signals of three primary colors corresponding to the pixel position from the time array signal corresponding to the video. . This pixel extraction is performed in response to designation of the storage address of pixel data by the address control device 22. The extracted pixel signal is converted by the pixel data generator 21 into a data array that can be written into the memory, and is written into the video memory section 11 under the control of the storage controller 20.

When writing to the video memory section 11 is completed,
A write end command is sent from the address control device 22 to the image printer control device 22. When the image printer control device 22 receives this command, it combines the image data read out from the video memory section 11 with the printer mechanism control command etc. under the control of the general control block 16, and sends the image data via the switch 15. , and sent to the printer mechanism section 12. As a result, the printer mechanism section 12 prints the stored color image.

The switch 15 is for switching between the printer signal input from the Centronics interface connector 8 and the color image print signal from the video memory section 11. The operation panel 17 is used by the user of this color printer to input commands necessary for operation.
Commands from the operation panel 17 are sent to the general control block 1.
6, the general control block 16 issues necessary commands to each section. The general control block 16 is composed of a microcomputer, and is designed to perform the various processes described above.

FIG. 3 is a block diagram showing the simplest embodiment of the configuration of the operation panel 17 in FIG. 2.

30 is a start switch for instructing the printer to output a video signal; 31 is a switch indicating whether the image to be printed is monochrome or chrome;
A mode changeover switch 32 is used to notify the printer of the present invention of information as to whether the image is in color or not; 32 is an operating switch that converts video signal information for the printer and notifies the user that the printout operation is in progress; An indicator light 33 indicates whether the current operating mode is monochrome, color, or monochrome; 16 a general control block; 34 a second control block;
These lines represent the signal connections from the general control block 16 to the respective devices in the figure.

There are several types of video signals (signals adapted to operate CRT display devices) in the world, commonly known as NTSC signals, PAL signals,
Four types of signals, CECAM signal and RGB signal, have become mainstream, and the three types mentioned above excluding RGB signal are commonly called composite, and RBG signal is commonly called RGB.

Also, among the four formats mentioned above, the one that is used for monochrome, color, and color is the same format as the NTSC signal.
It is an RGB signal, and in Japan, the NTSC signal is called composite, and the RGB signal is called RGB.

There are two main types of video signals as described above. The composite signal consists of a horizontal synchronization signal, a vertical synchronization signal, a video signal, and a burst signal, which are mixed according to TV standards. In the RGB signal, a red video signal designated by R, a green video signal designated by G, a blue video signal designated by B, a vertical synchronization signal, and a horizontal synchronization signal are transmitted on separate signal lines.

Since these two types can be changed together, an example using an RGB signal type video signal will be described. The screen displayed on a CRT is composed of horizontal scanning lines and vertical scanning lines, and the period from the trailing edge of a horizontal sync signal to the leading edge of the next horizontal sync signal is the distance from the left edge of the raster in the horizontal direction. is linearly proportional to The same is true in the vertical direction; the distance from the trailing edge of a vertical sync signal to the leading edge of the next vertical sync signal is linearly proportional to the distance from the top edge to the bottom edge of the raster.

However, the value of images on a CRT display varies depending on the computer, but
smaller than that. Also, the resolution of the image is
The computer assigns numerical values such as 640, 320 in the horizontal direction and 400, 200, 100, etc. in the vertical direction.

The printer of the present invention may have means for self-synchronously generating this pixel signal, which is not transmitted within the RGB video signal. This generation is produced by a double heterodyne frequency conversion and a frequency/phase lock loop, and is determined by the mutual control of the synchronization control device 26 and the image range selection gating device 25.

In this way, the pixel extraction gate device 23 is synchronized with the video output clock in the computer.
Address control device 22, pixel data generation device 2
1. By using the storage control device 20, the same data arrangement as that on the V-RAM in the computer is reproduced on the image data storage device 18.

Using the reproduced image storage data, the image printer control device 19 selects complementary color 3 from RGB.
The pixel signals converted as primary color MCY (magenta, cyan, yellow) data and black data are combined with printer control commands in the same device and sent to switch 1.
5 to the printer.

These operations are performed throughout the storage device 18. The printer then prints out the same image as the CRT display screen. When the printout is completed, the image printer control device 19 issues a completion signal to the general control block 16, resets the switch 15, connects the signal from the Centronics interface connector 28 to the printer, and switches the control of the printer to the Centronics. - Hand over to interface.

Since the color printer according to the present invention has a configuration including a video signal input interface section and a video memory section as described above, no matter what model the computer side is, it can print the color image currently displayed on the CRT screen. This has the remarkable effect that it is possible to output the image directly to the color printer section, eliminating the need to have a color copy program for each model of personal computer, as was the case in the past.

By increasing the capacity of V-RAM, it is possible to store information equivalent to several CRT screens, which has the effect that the computer side can apparently work separately from the printer side. It is possible to arbitrarily set the number of copies.

Furthermore, if the printer has means for self-synchronously generating pixel signals that are not transmitted to the video signal, the resolution of the image on the CRT display can be set according to the computer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of computer peripheral connections using a color printer, which is an embodiment of the present invention. FIG. 2 is a block diagram of each internal mechanism for explaining the operation of a color printer including an interface section and a video memory section according to the present invention. FIG. 3 is a block diagram showing one embodiment of the configuration of the operation panel in FIG. 2.

Claims (1)

[Scope of utility model registration request] a video signal input interface section for inputting video information including colors displayed on a computer display; a video memory section for storing video information input through the video signal input interface section; and a video memory section for storing video information input through the video signal input interface section. 1. A color printer for a computer, comprising: a printer control section that outputs video information stored in the computer to a printer mechanism section.