JPH0548461B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image information reading device that improves the reading speed of image information without changing the scanning speed of a laser beam.

It can also be applied to reading images on general originals (as recording media), but in this case, a stimulable phosphor that stores radiation image information is scanned with excitation light to emit light, and the emitted light is focused. 2. Description of the Related Art A radiation image information reading device is known that collects light with a photoconductive material and guides it to a photodetector to obtain an image signal, and this radiation image reading device will be described. In this type of reading device, an excitation light beam of approximately constant intensity is deflected by an optical deflector such as a rotating polygon mirror or a galvano mirror, and is irradiated with X-rays in an imagewise manner onto the surface of a stimulable phosphor on which information has been formed. is scanned in the main scanning direction and irradiated with a laser beam to read image information emitted (for example, stimulated luminescence). In order to increase the reading speed, it is necessary to increase the deflection speed of the deflector, but since there is a limit to that speed, it has been difficult to increase the reading speed that much.

The present invention has been made in view of the above points, and aims to increase the reading speed of radiographic image information by forming a plurality of scanning lines for each deflection scan while maintaining the deflection speed of the deflector as before. This is what I did.

The present invention will be explained below based on the drawings.

FIG. 1 is a schematic diagram of an embodiment of an image reading device according to the present invention, and lenses and the like provided at various locations on the optical path are omitted. 1 and 2 are laser beams L ₁ ,
a laser oscillator that generates L ₂ ; 3 and 4 are optical modulators that modulate the laser beams L ₁ and L ₂ , respectively; 5;
6 is a slit through which only the modulated laser beam passes; 7 and 8 are the modulated laser beams L′ ₁ ,
It is a mirror that reflects L′ ₂ and irradiates it onto a deflector 9 as two slightly shifted beams, and the deflector 9 directs the two beams onto a stimulable phosphor plate 10 that moves in the direction of the white arrow. Deflection scans in the X direction at .
As the deflector 9, a galvanometer mirror or a rotating polygon mirror that rotates at a constant period as shown by the arrow is widely used for scanning.

FIG. 2A is a schematic enlarged view of the irradiation state of a plurality of scanning beams in order to explain the present invention in an easy-to-understand manner. The figure shows the relationship between the laser beam (the beam spot is indicated by a circle in the figure) and the scanning line; the laser beam _L1 scans on the n line, and the laser beam scans on the n+1 line
L ₂ scans. When a laser beam is scanned over the phosphor plate 10 to excite the phosphor to emit light, the amount of light emitted by the n line D _o is shown in Figure 2B, and the amount of light emitted by the n+1 line D _o+1 is shown in the figure C. In this case, the total amount of light emitted will be as shown in D of the same figure. Returning to FIG. 1 again, the emitted light from the phosphor plate 10 is guided by a light condensing conductor 11 to a photodetector 12 where it is photoelectrically detected. In this case, the optical modulators 3 and 4 are turned on and off alternately to turn the laser beams L ₁ and L ₂ on and off, and in synchronization with the turning on timing, the two laser beams in the signal processing circuit 13 are turned on and off.
two sampling apertures A, B (not shown)
Open and close as shown in Figure 2 E and F. As a result, the signal processing circuit 13 obtains a signal as shown in FIG. 2G as an n-line image signal, and a signal as shown in FIG. 2H as an n+1-line image signal. The subsequent image signal processing is no different from the previous processing.

FIG. 3 shows an example of the signal processing circuit 13, in which the image signal output from the photodetector 12 is converted to a voltage level by the current-voltage converter 13a, sampled and held by the clock _CL1 in the sampling and hold circuit 13b, and then The D converter 13c converts the signal into a timing digital signal of the clock _CL2 , and the necessary processing is performed by the electronic computer 13d.

In this way, image information of a plurality of scanning lines obtained from one photodetector 12 is transmitted to the signal processing circuit 1.
3, the data is read cyclically in a time-division manner.
That is, for example, it is possible to use a complex configuration in which multiple scanning lines are irradiated with light beams of different wavelengths, and each scanning line is provided with a plurality of photodetectors that detect only light beams of specific wavelengths. First, image information of multiple scanning lines can be read simultaneously with a simple configuration.

The above embodiment is an example in which two laser beams are used to excite and emit two lines of pixels in one scan, but as shown in FIG. 4, three lines (n, n+1, n+2 lines) in one scan. The pixels may be arranged in a straight line, or the pixels may be arranged in an equilateral triangular arrangement as shown in FIG. 5, and a plurality of different lines may be time-divisionally scanned for high-speed reading. In this way, the reading speed is further improved.

In FIG. 6, unlike the embodiment shown in FIG. 1, the laser beam L generated from one laser oscillator is time-divided into a plurality of laser beams having different deflection angles by a deflection dividing means 15 such as an acousto-optic element. The divided beams are divided into beams, each divided beam is scanned by a deflector 16 over a plurality of different lines on a stimulable phosphor plate 17, and the emitted light is sent to a photodetector 19 by a condensing conductor 18.
to conduct photoelectric conversion. The image signal output from the photoelectric converter 19 is amplified by an amplifier 20 and then subjected to image processing by an image processing circuit 21.

Although the above embodiment has been exemplified with respect to a reading device for radiation image information stored on a stimulable phosphor plate, the present invention can also be applied to an ordinary document reading device, and the reading speed can be improved.

As explained above, the present invention provides an image information reading device that scans an image information recording medium by deflecting a light beam with an optical deflector and obtains an image signal based on the emitted light or reflected light from the recording medium. A light beam generating means for generating a plurality of light beams is provided, the plurality of light beams from the light beam generating means are made incident on the optical deflector, and when the deflector is moved by one scanning angle, the light beams are projected onto the recording medium. Since a plurality of scanning lines are formed, the reading speed can be improved without changing the scanning speed of the light beam, and high-speed reading becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of an image information reading device according to the present invention, and FIGS. Time chart, FIG. 3 shows one embodiment of the signal processing circuit used in the image information reading device shown in FIG. 1, FIGS. 4 and 5 show other examples of the scanning mode of the laser beam, and FIG. FIG. 3 is a schematic diagram of another embodiment of the image information reading device according to the present invention. 1, 2... Laser oscillator, 3, 4... Optical modulator, 5, 6... Slit, 7, 8... Mirror,
9, 16...Deflector, 10...Storage phosphor plate,
11, 18...Light collecting conductor, 12, 17...Photodetector, 13...Signal processing circuit, 13a...Current voltage converter, 13b...Sampling hold circuit, 13c...A/D converter , 13d...electronic computer, 15...deflection dividing means, 19...photoelectric converter, 20...amplifier, 21...image processing circuit.

Claims (1)

[Scope of Claims] 1. A light beam generating means for generating a plurality of light beams, and an image recording system in which the plurality of light beams emitted from the light beam generating means are incident, and an image is recorded by deflecting each light beam. an optical deflector that forms a plurality of scanning lines at different positions on the medium; a light modulator that turns on and off the plurality of light beams from the light beam generating means in a time-sharing manner; a moving means that moves in a direction substantially perpendicular to the image recording medium; a photodetector that converts light from the image recording medium into an electrical signal; Image information comprising: a light condensing conductor that guides light to the photodetector; and a signal processing means that reads an image signal from the photodetector in synchronization with turning on and off of the light beam. reading device. 2. A light beam generating means for generating one light beam, a deflection splitting means for time-sharingly dividing the light beam emitted from the light beam generating means into a plurality of beams having different deflection angles, an optical deflector that deflects each incident light beam to form a plurality of scanning lines at mutually different positions on an image recording medium on which an image is recorded; and moving the image recording medium in a direction substantially perpendicular to the scanning line. a photodetector that converts light from the image recording medium into an electrical signal; and a light-converging surface extending along the scanning line, the light incident on the light-converging surface is transmitted to the photodetector. An image information reading device comprising: a light condensing conductor that guides the light beam; and a signal processing means that reads an image signal from the photodetector in synchronization with time division of the light beam.