JPH0211160Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image rotation compensation circuit for a phototypesetting machine, etc., which is equipped with a pattern scanning type character signal generator such as an image pickup tube or a monoscope tube.

FIG. 1 is a schematic diagram showing an embodiment of a phototypesetting machine in which, for example, an image pickup tube is used as a character signal generating section and a cathode ray display tube (hereinafter referred to as CRT) is used as a character reproducing section. A dial containing symbols, etc. (hereinafter referred to as characters), 2 is an image pickup tube, 3 is a CRT,
Reference numeral 4 denotes a sensitive material, which reproduces a character image projected onto the image pickup tube 2 by a light source 5 onto a CRT 3, and further projects the reproduced image onto the sensitive material 4 to create a printed matter.

However, in such a phototypesetting machine, if the character image is not projected at a predetermined position on the image pickup tube 2, or if the projected image is rotated, the position and orientation of the character reproduced on the CRT 3 will not be constant. Inconveniences arise in that characters printed on the photosensitive material 4 vary, and the print quality required for photographic prints cannot be met.

Conventionally, a position detection mark is applied to each character at a predetermined position. For example, as shown in FIG. There is a known configuration in which the amount of deviation from a predetermined position is detected by scanning only the character, and the deflection signal for character scanning is corrected based on the amount of deviation so that the desired location can be accurately scanned. In the conventional configuration, even if the positional deviation in the X and Y directions could be compensated for, it was impossible to compensate for the rotation of the character image. Therefore, in order to prevent the influence of image rotation, the dial manufacturing precision, optical system precision, or characteristics of the light source control circuit, which are the causes of the image rotation, must be maintained at a high level, which reduces the manufacturing adjustment time and This was a factor that hindered cost reduction.

The present invention was developed in view of the above points, and its features include a dial having a plurality of characters and a position detection mark added one-to-one to each character; an imaging means for capturing and scanning a desired character and a position detection mark on a board; a counter for counting the number of scanning lines based on the scanning line in which the mark was first detected in preliminary scanning of a raster area containing the position detection mark; first and second coincidence detection circuits that compare the counted value of the counter with two predetermined values n and n+α; first and second registers in which the distance from the scanning start point of each scanned line to the position detection mark position is set as a count value;
and a subtraction circuit that subtracts the value of the second register to obtain the difference c, and inputs the difference c obtained by the subtraction circuit and the value of α, and outputs a deflection signal to the imaging means by tan ⁻¹ (c /α) to compensate for the rotation of the character image on the surface of the imaging means.

The present invention will be explained in detail below using the drawings.

FIG. 3 is a diagram showing an example of the circuit configuration according to the present invention, in which 31 is a horizontal synchronizing signal for readout scanning of the image pickup tube, 32 is a character signal read out from the image pickup tube, 33 is a flip-flop, and 34 is a counter. ,
35 and 36 are registers in which predetermined values n and α are set; 37 is an addition circuit; 38 and 39 are coincidence detection circuits; 40 and 41 are registers that take in data in response to the outputs of AND gates 42 and 43; The delay circuit, 45 is a subtraction circuit, and 46 is a subtraction circuit.
X which is a deflection circuit of CRT47 and moves in response to pulses supplied from a circuit not shown in the figure.
The X and Y deflection signals 50 and 51 are outputted to the CRT 47 by the D/A converter outputs of the Y direction counters 48 and 49.

FIG. 4 shows the deflection system on the image pickup tube surface 52.
XY coordinates and a pair of character images 53 projected onto the tube surface 52 while being rotated by an angle θ with respect to the coordinate axes.
This is an explanatory diagram showing the relationship between the position detection mark 54 and the position detection mark 54, and 55 is a raster area for reading the position detection mark 54.

FIG. 5 shows the X and Y deflection signals 50, 5.
1, a timing chart of the horizontal synchronization signal 31 and the character signal 32.

In the present invention, the character image 5 projected on the tube surface 52
Before scanning 3, first scan the position detection mark 5.
4 scans are performed. This scanning scans the raster area 55 set in advance on the tube surface 52, and in the case shown, the scanning starts from point P and ends at point Q after passing through an arbitrary number of scanning lines. is set to .

During this raster scanning process, when the scanning line S ₀ reaches point R, one end of the mark 54 is read out, and a corresponding character signal 32 _-0 is generated.
The flip-flop 33 shown in FIG. 3 is set by the first output character signal in this way. Next, when moving from the scanning line S ₀ to the next scanning line S ₁ , the counter 34 increments to "1" by the horizontal synchronizing signal 31 _-1 , and thereafter the counter 34 increments to "1" for each horizontal synchronizing signal.
1" step at a time. Therefore, the value of the counter 34 is N when the Nth scan is performed from the scanning line _S0 . When the value of the counter 34 reaches n, the coincidence detection circuit 38 operates and outputs a signal to the AND gate 42. When the scanning line Sn reaches the point T in FIG. 4, the mark 54
A character signal 32 _- n is generated. This signal then passes through the AND gate 42 of FIG. 3 and operates the register 40, which takes in and stores the value of the X counter 48 at that time. The value thus stored in register 40 is equal to a of the X deflection signal 50 shown in FIG.
End T of mark 54 from scanning start point in Sn
The value corresponds to the distance to. Similarly, a value b corresponding to the distance from the scanning start point on the scanning line Sn+α to the end U of the mark 54 is set in the register 41. After the value b is set in this register 41, the subtraction circuit 45 operates after a predetermined time by the delay circuit 44 (b-a).
A value corresponding to =c is output. As is clear from FIG. 4, the ratio between the value c thus obtained and the set value α, that is, C/α, is the tangent of the rotation angle θ.

Incidentally, the following relational expression holds between the XY coordinate and the X'Y' coordinate obtained by rotating the XY coordinate by an angle θ. That is, x′=xcosθ−ysinθ y′=ycosθ+xsinθ And as mentioned earlier, in Fig. 4, tanθ=c/
Since α, x′=(αx−cy)/√ ² + ² y′=(αy+cx)/√ ² + ² .

FIG. 6 is a diagram showing an example of a coordinate rotation circuit for obtaining a deflection signal with compensation for the rotation angle θ based on the above relational expression, and 61 is a value obtained as described above by the circuit in FIG. a register, 62, in which c is set;
63 is a D/A converter, and 64 to 72 are arithmetic circuits.

As mentioned above, after scanning the position detection mark 54 in advance to obtain the desired value c, the deflection signals x and y for scanning the character image are inputted to the circuit shown in FIG. When the output signals x' and y' are applied as deflection signals to the image pickup tube, the rotation angle θ is compensated, and the desired character image 53 can be accurately scanned.

As described in detail above, the present invention has an image pickup tube readout circuit that scans a position detection mark in advance before scanning a character image. Each distance from the scanning start point to the mark position on the main scanning line is detected, and the difference c between the detected values and the set value α
The present invention provides an image rotation compensation circuit for a phototypesetting machine in which a predetermined range of a rotated character image is scanned by inputting the following into a coordinate rotation circuit, whereby the character image projected onto an image pickup tube is rotated. Since the desired signal can be generated accurately by using the predetermined section of the position detection mark even when the dial is in use, the manufacturing precision of the dial and the adjustment precision of the optical system can be relaxed, reducing work time and costs. It contributes to

Although the above explanation has been about a type in which desired characters are projected from a dial onto an image pickup tube, the present invention can be applied to any type of device in which the pattern scanning means is used as a character signal generating section. For example, it can be applied to a monoscope tube or a flying spot tube type. Further, the printing section is not limited to one using a CRT, but may be of any type as long as it reproduces characters by scanning according to character signals, such as an inject type. Furthermore, in the above explanation, the left end of the position detection mark 54 is detected and the register 40 is
and 41 have been described, but in short, it is sufficient to detect the mark position, and it is of course possible to detect the right end or center.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of a phototypesetting machine;
Figures 2 and 4 are explanatory diagrams of the character projection state on the image pickup tube, Figure 3 is a diagram showing an example of the circuit configuration of the present invention, Figure 5 is a timing chart of each signal, and Figure 6 is a deflection diagram. FIG. 3 is a diagram showing an example of a signal coordinate rotation circuit. 31...Horizontal synchronization signal, 32...Character signal, 3
4... Counter, 35, 36... 40, 41... Register, 38, 39... Coincidence detection circuit, 44...
Delay circuit, 45... Subtraction circuit, 46... Deflection circuit, 50... X deflection signal, 51... Y deflection signal,
52... Image pickup tube surface, 53... Character image, 54...
Position detection mark, 55... Raster area.

Claims (1)

[Scope of Claim for Utility Model Registration] A dial face having a plurality of characters and a position detection mark added on a one-to-one basis for each character, and an imaging means for imaging and scanning desired characters and position detection marks on the dial face. and a counter that counts the number of scanning lines based on the scanning line where the mark is first detected during preliminary scanning of the raster area containing the position detection mark, and the count value of the counter and two predetermined values n and first and second coincidence detection circuits that compare n+α, and according to the coincidence detection signals from each coincidence detection circuit, from the scanning start point of each scanning line specified by the detection signal to the position detection mark position. first and second registers in which the distance of is set as a count value, a subtraction circuit that subtracts the values of the first and second registers to obtain the difference c, and the difference c obtained by the subtraction circuit. The value of α is input, and the deflection signal for the imaging means is tan ⁻¹ (c/
1. An image rotation compensation circuit for a phototypesetting machine, comprising: a deflection signal coordinate rotation circuit that rotates the coordinates by α), and is configured to compensate for rotation of a character image on a surface of an imaging means.