JPH0263098A - Image display method for cad - Google Patents

Abstract

PURPOSE:To realize a partial moving image at a low scanning frequency by projecting the still image plane of a still image display device and the moving image plane of a moving image display device on a screen one over the other. CONSTITUTION:The display device 5 is scanned at the low frequency so as to display the still image. Either a raster scan or vector scan is employed for the scanning system for the still image. In general, a cursor display of CAD is made with simple vector constitution like a cross mark. In this case, many planes can be rewritten by the vector scan in one second even at the low scanning frequency and the moving image can be realized on the display device 6. A drawing on the screen of the display device 5, i.e. still image and a cursor on the screen of the display 6, i.e. moving image are displayed on the same plane of the screen 13 one over the other. Consequently, the moving image is realized on a part of the screen at the low scanning frequency and the best display system for CAD is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image display method used in CAD, that is, a computer-aided drafting system.

[Conventional technology]

In the past, high scanning frequency control has been performed using a storage tube in video display in which complex video graphics are displayed on the screen of a display device.

[Problem that the invention seeks to solve]

The use of a high scanning frequency CRT (display device) for displaying moving images requires expensive hardware including a controller to operate it, and maintenance is also extremely difficult. In order for the display device to make the video visible to the human eye, 1.
A fairly high scanning frequency is required to achieve such speed in a display device with a large number of zero pixels, which requires rewriting 24 screens per second.

On the other hand, a display device using an element that stores an input image, such as a known light valve, can practically display still images even at a low scanning frequency.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display method that realizes a partial moving image at a low scanning frequency on a display device having a plurality of scanning systems.

In the present invention, at least one of the plurality of scanning systems must perform vector scanning, and this scanning system is used for moving images. The scanning system other than the moving image scanning system may be either raster scanning or vector scanning.

For example, when this method is used for a CAD user display, a cursor is displayed in a moving image scanning system, and a drawing is displayed in another scanning system. At this time, since the drawing display screen does not need to be a moving image, it is scanned at a low scanning frequency. On the other hand, since the cursor display must be moved in response to the operator's operations, it must be displayed as a moving image. If the cursor display has a simple vector configuration such as a cross mark, vector scanning allows a large number of images to be rewritten per second even at a low scanning frequency, making it possible to create moving images.

The present invention eliminates the above defects based on this idea.
The purpose of this invention is to provide an image display method for AD.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for displaying drawing data and a moving image consisting of a simple vector structure such as a cursor on a screen, in which one drawing data is used as a still image on a display device. The video data consisting of a relatively simple vector structure is displayed on another display device by vector scanning at a low scanning frequency, and the still screen of the still image display device and the video display device are The video screen is superimposed on the screen and projected.

〔Example〕

The structure of the present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

Reference numeral 1 denotes a processor, which writes data corresponding to drawing display into the image memory 2.

This data is read out by the raster scan converter circuit 3 and sent to the still image display device at a low scanning frequency.
(CRT) 5 screen.

The processor 1 also provides vector data for cursor display to the vector scan converter circuit 4. This vector data is a video display device (CRT) 6
displayed on the screen. Display images of the still image display device 7 and the video display device 6 are displayed using a light valve 7.
8 is input.

This light valve 7.8 constitutes a device that converts an input image into a clear image and irradiates it to the output side.
．． The configuration and principle of the device No. 8 are disclosed in detail in US Pat. No. 3,723,651, US Pat. 11 is a light source;
This light is input and reflected to a light valve 7.8 via a half mirror 10 and a beam splitter (polarizing prism) 9, and the images of the display devices 5 and 6 are enlarged and projected onto a screen 13 by a projection lens 12. be.

In the above configuration, the display device 5 is scanned at a low scanning frequency in order to display a still image. The still image scanning system may be either raster scanning or vector scanning. C
The cursor display in AD is generally a simple vector configuration such as a cross mark, and in this case, vector scanning allows a large number of images to be rewritten per second even at a low scanning frequency, and the display device 6 It is possible to realize the video. A drawing, ie, a still image, on the screen of the display device 5 and a cursor, ie, a moving image, on the screen of the display device 6 are displayed superimposed on the same plane of the screen 13.

〔effect〕

As described above, the present invention has the advantage that it is possible to realize a moving image on a screen using a low scanning frequency, and is most suitable as a CAD display method.

[Brief explanation of the drawing]

The figure is an explanatory diagram showing a preferred embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Processor, 2... Image memory, 3... Raster scan converter circuit, 4... Vector scan converter circuit, 5... Display device, 6...
Display device, 7... Light valve, 8... Light valve, 9... Polarizing beam splitter, 10...
・Half mirror 111...Light source, 12...Projection lens, 13...Screen

Claims (1)

[Claims] (1) In a method of displaying drawing data and a moving image consisting of a simple vector configuration such as a cursor on the screen,
Drawing data is displayed as a still image on a display device at a low scanning frequency, moving image data consisting of a relatively simple vector configuration is displayed on another display device by vector scanning at a low scanning frequency, and the display device for still images is A CAD image display method characterized in that a still screen and a video screen of a video display device are projected onto a screen in an overlapping manner.