JPS60109376A - Radiant ray picture reader - Google Patents

Abstract

PURPOSE:To accelerate data transfer by using at least two units of picture memory for data transfer alternately. CONSTITUTION:When a data transfer possible signal is received from an external device side, a control circuit 25 transmits a control signal to a driving system 21, a reading system 22 and changeover switches SW1 and SW2, and starts a reading operation at a prescribed speed. The read-out data are outputted from the reading system 22, and stored in a picture memory M1 through the changeover switch SW1. Since the picture memory M1 is filled after one-line picture information is read out, the control circuit 25 switches the changeover switch SW1 from the picture memory M1 side to the picture memory M2 side. At the same time, the changeover switch SW2 is switched and connected to the picture memory M1 side.

Description

Detailed Description of the Invention (Technical Field) The present invention irradiates an information recording medium with a laser beam through an optical system and moves the information recording medium in the main scanning direction, and (1) transports the information recording medium in the sub-scanning direction. The present invention relates to a radiation image nail reading device which obtains reflected light or transmitted light from the information recording medium and photoelectrically converts it to obtain image information.

(Prior Art) A radiation image reading device is known that converts image information recorded on an information recording medium such as a radiation film into an electrical signal using an optical system, and then extracts the electrical signal as image information. Specific examples of such devices include photostimulable phosphor readers and film readers. In this type of device, a laser beam is focused on an information recording medium using an optical system and is scanned over the information recording medium in the main scanning direction, while the information recording medium itself is conveyed in the winding direction (sub-scanning direction). It is configured to read all recorded information recorded on the information recording medium. That is, an information recording medium is irradiated with a laser beam, and the reflected light (in Suimei III!!, stimulated luminescence light is included in the reflected light) or transmitted light is converted into an electrical signal by a photoelectric conversion element, and an image is generated. It obtains electrical signals according to information.

By the way, this type of radiation image reading device may be connected to a computer as an input/output terminal to perform data processing. In such a case, the data transfer rate changes depending on the amount of operation of the terminal or the exclusive time of the computer. This Iζ
To ensure data transfer for all cases, set the data transfer rate to the rate corresponding to the slowest case, or set the Ic capacity to the memory (e.g. In the case of 2000x2000x8 bit data, it is necessary to take a method such as having 4 megabytes) and transferring it all at once after reading is completed. As in the former case, if you use the slowest data transfer rate,
It takes a huge amount of time to read a single image, and the computer is occupied for a long time, reducing the overall efficiency of the system. On the other hand, as in the latter case, in a system with a large capacity memory, the device itself becomes large and the cost, including the reliability of the memory itself, becomes extremely high.

In addition, in this type of device, if the reading operation is stopped midway, when a phosphor plate is used as the information reading medium, the laser beam scans the same place, or when a film is used as the information recording medium, There is an inconvenience that light enters a photoelectric conversion element such as a photomultiplier (hereinafter referred to as photomultiplier 11111-) even during non-reading. That is, when the laser beam scans the same location on the phosphor plate J°, the information about the scanning position is lost and the phosphor plate 1 of the laser beam
Due to the diffusion in the area, information in adjacent areas of the scanning lines is also lost. Therefore, if you output an image with a reading operation in which sub-scanning is stopped midway, the image will have horizontal streaks.1. On the other hand, in the following film reader, the reading light is applied to the photocolumn etc. even when not reading, shortening the life of the photocolumn etc. Furthermore, in the case of the conventional device, the conveyance speed to the phosphor plate 1 is constant regardless of the reading location, and the conveyance to the reading position is the same as the reading speed, so the overall reading time is reduced. It takes a lot of time.

(Objective of the Invention) The present invention has been made in view of the above points, and its object is to enable high-speed data transfer even when data is transferred by connecting to a computer, and to stop sub-scanning midway through the data transfer. Even in such a case, an object of the present invention is to realize a radiation image reading device that can start the reading operation from the next reading position without error when restarting the reading operation.

(Groove Bottom of the Invention) The present invention achieves the above object by moving and irradiating the information recording medium in the main scanning direction with Rayleigh light through an optical system, and at the same time moving the information recording medium in the sub-scanning direction. In a radiation image reading device that is relatively conveyed to obtain reflected light or transmitted light of the information recording medium and photoelectrically converts the light to obtain image information, a means for converting laser light into ΔnA;
At least two lines of image data that store image data, the flow of data into and from the image memory, the conveyance speed of the information recording medium in the sub-scanning direction, and the speed of the laser beam. This is characterized by the fact that it cooperates with a control circuit that controls the words A) and the like.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram showing an example of the configuration of a drive/reading system used in the reading device of the present invention. In the figure, 1 is an information recording medium such as a fluorescent plate or film, 2 is a laser, 3 is a polygon mirror that moves the laser beam in the main scanning direction (X direction in the figure), and 4 is a polygon mirror that moves the polygon mirror 3 in a certain direction. 5 is a polygon mirror 3 that rotates at a constant speed.
A mirror 6 that receives the reflected light is a step rotor that rotates the information recording medium 1 in the sub-scanning direction (Y direction in the figure). The step motor 6 and a plurality of rollers 7 on which the information recording medium 1 is placed constitute a conveyance machine. Reference numeral 8 denotes an optical fiber that condenses the reflected light from the information recording medium 1 and guides it to the ゛°C photoelectric conversion element.

As the photoelectric conversion element 9, for example, a photomultiplier is used. 10 is an amplifier circuit such as a logarithmic converter that amplifies the output of the photoelectric conversion element 9, and 11 is an A/D converter that converts the output of the amplifier circuit 10 into digital image data.

In the LC device configured in this manner, the output light of the laser 2 is waved by the polygon mirror 3 and is irradiated onto the phosphor surface or film surface of the information recording medium 1 to perform main scanning. In the case of a phosphor reader, a condensing system such as an optical fiber 8 is used to direct only the light emitted from the information recording medium (phosphor plate) 1 to the photoelectric conversion cable 9 at λ9. On the other hand, in the case of a film reader, the film 1 is irradiated with Ray light, and the transmitted or reflected light is guided to the photoelectric conversion cable 9 using a condensing system such as an optical fiber 8. . Sub-scanning in the Y direction is carried out using the step motor 6 of the front J. No. 21 is an explanatory diagram of another configuration example of the drive/reading system used in the reading 11 apparatus of the present invention. The phase jl with FIG. 1 is that in FIG. 1, reflected light from the information recording medium 1 is used as the Okawa light to the photoelectric conversion element 9, but in FIG. 2, transmitted light is used instead of reflected light. The rest of the configuration is exactly the same as in FIG.

Next, Figures 1 and 2 show the J drive/reading system and I (
A reading device (an embodiment of the present invention) will be described. FIG. 3 is an electrical configuration diagram showing one embodiment of the control system in the apparatus of the present invention. In the figure, 21 is a drive system that moves the laser beam in the main scanning direction and conveys the information recording medium 1 (see FIG. 1) in the sub-scanning direction, and 22 also moves the image information recorded on the information recording medium 1. This is a reading system that optically reads and outputs. Both the drive system 21 and the reading system 22 are simplified representations of the 4M component elements indicated by J3 in FIGS. 1 and 2. M1 and M2 are image memories each storing one line of image data in the main scanning direction of the information recording medium 1, and output data from the reading system 22 is sequentially stored therein. S W 1 is the image memory M1. S W 2 is a selector switch for selecting one of the image memory outputs, 23
24 is an interface for sending the contents of the image memories M1 and M2 to an external device such as a computer, 24 is an interface for taking command signals from the external device into the internal control system, and 25 is an interface for outputting command signals from the interface 24. This is a control circuit that provides control signals to the receiving drive system 21 and the reading system 22, and also controls switching of the changeover switches swr and sW2. .

The operation of the embodiment configured as described above will be explained as follows.

When receiving a reading start signal from an external device, this reading Cnn
The signal is sent to the control circuit 25 via the signal doubler interface 24. When the control circuit 25 receives the reading start signal, it sends a sub-scanning control signal to the drive system 21, and the control circuit 25 sends a sub-scanning control signal to the drive system 21, and moves the normal reading unit J to the reading start position. '1 is transported. The operation of changing the setting of the information recording medium 1 to the first position has nothing to do with reading information, so it is better to do it as fast as possible for the overall '7 High Speed Reading J1
ν will be 1. Next, upon receiving a data transfer enable signal from the external device side, the control circuit 25 sends a control signal to the drive system 21, reading system 22, and changeover switches SW+ and SW2, and reads the reading operation at a predetermined speed. Jru.

The read data is output from the reading system 22, passed through the changeover switch S W +, and stored in the image menu Ml.

When one line of image information is read, the image is 1g! Since the memory M1 becomes full, the control circuit 25 switches the selector switch S.
Switch W + from the image memory M1 side to the image memory M2 side. At the same time, the changeover switch SW2 is also switched and connected to the image memory Mi side. In this state, the image information of the next line is read and stored in the image memory M2.

During this time, Memory M! The 181Pi-C image data is transferred to an external device via the interface 23. When image memory M2 is full, selector switch S
W+ and SW2 are switched to the opposite side at the same time,
The data of the next line is stored in the image display Ml again,
The contents of the image memory M2 are sequentially transferred to an external device. In this way, efficient data transfer can be achieved by alternately using the two image memories M+ and tv12 for loading and reading.

If the data transfer goes smoothly, the data will be transferred to the end by repeating these operations. By the way, during a reading operation, a transfer prohibition signal may be sent from an external device. At this time, the control circuit 25 stops the data transfer from the image memory during data transfer at the time when this transfer disable signal is detected. However, the reading operation does not stop until the reading of that line is completed. The reason is,
This is because if you avoid stopping the reading operation in the middle of the line, it will be difficult to perform accurate positioning when reading resumes. Therefore, that line () performs a reading operation μ, stores the data in the image media, and then sets the radar 2 to A off and drives the drive system 2.
Stop 1 11 Prohibits sub-scanning from proceeding to the next step. In this state, a data transfer enable signal is received from the external device. When a data transfer enable signal is sent, the laser is turned on and sub-scanning is started. still,
When restarting sub-scanning, it is necessary to synchronize in the main-scanning direction. This is because there is a possibility that the storage turns on in the middle of one line. By adopting the above configuration, it is possible to use the maximum possible data transfer rate, and it is also possible to save on image consumption. This image memory requires at least 2 lines (1 line x 2), and in practice, about 20 lines (10 lines x 2) is sufficient. This is to avoid irradiating the light body plate with unnecessary laser light. The following methods are available for this purpose.

(1) A method of increasing the extinction ratio by using two stages of Pl-back optical modulation elements (hereinafter referred to as AOM). Each of the 〇M and 〇M turns on at the same time, and either one or both can also serve as a light stabilizing function. According to one stage AOM, the extinction ratio is 1/
Although it is small at around 1000, light may leak and change the image. For this reason, two stages of 80M are used.

(2) A method using one stage of AOM and one stage of mechanical shaft 11. If the reading speed can be made slow enough, that is, if the operating time of the mechanical shutter is long enough to catch up, the extinction ratio can be made very large using this method.

(3) A method of using one stage of AOM, moving the AOM to A and simultaneously performing sub-scanning in the opposite direction so that the main-scanning line becomes the line that has already been read. Using this method,
Even if light leaks, it has no effect.

By using the above method, information on locations that have not yet been read will not be lost.

It should be noted that, although the above description has mainly been given with reference to a phosphor reader as an example, it can be similarly applied to a film league. 1[1shi, in this case +f 2 is covered with -4 to prevent more than necessary light from entering the photocathode of the photomultiple.

<Effects of the Invention> As explained above, according to the present invention, data transfer l
The data transfer rate can be increased by 4-4 by using at least two image-recording devices for each signal.

In addition, the control circuit can control the loading and unloading of data into the memory, the conveyance speed in the sub-scanning direction, and the ∆ turn-off of the storage, so even if sub-scanning is stopped mid-way, there is no need to worry.
i? Circle the reading without 5.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the structure of a drive/reading system used in the reading device of the present invention, FIG. 2 is an explanatory diagram showing another example of the drive/reading system, and FIG. FIG. 2 is an electrical configuration diagram showing an example of a G-Fu control system. 1... Information recording medium 2... Laser 3... Polygon mirror 4... Motor 5... Mirror 6... Step motor 7... Roller 8... Optical fiber 9... Photoelectric conversion Element 10...Amplification circuit 11...
Δ/D converter 21... Drive system 22... Reading system 23.24... Interface 25... Control circuit Ml, M2... Image memory SV
V+, SW2...Switching Switch Special J1 Applicant Roku Konishi Photography Co., Ltd. 1st Generation Patent Attorney Fuji Osamu Ijima

Claims (5)

[Claims] (1) A laser beam is moved in the main scanning direction to the information recording medium through an optical system to illuminate the information recording medium, and the information recording medium is relatively conveyed in the sub-scanning direction, so that the reflected light of the information recording medium or A radiation image reading device that obtains transmitted light and photoelectrically converts it to obtain image information, which includes a means for turning off laser light, at least two lines of image memory for storing image data, and an image memory for storing image data. A radiographic image characterized by comprising a control circuit that controls the input of data and the readout of data from the memory, the conveyance speed of the information recording medium in the sub-scanning direction, the on/off of the laser beam, etc. reading device. (2) The radiation image reading device according to claim 1, characterized in that two high-acoustic optical modulation elements are used as means for turning on and off the laser beam. (3) The 131-ray image according to claim 1, characterized in that the means for turning on and off the laser beam is τ, one acousto-optic modulation element, and a mechanical shutter. reading device. (4) The radiation image reading device according to claim 1, 2, or 3, characterized in that the conveying mechanism is configured such that the sub-scanning direction is reversible. Device. (5) The radiation image reading apparatus according to claim 1, 2, or 3, wherein the transport mechanism is configured such that Jg2 degrees of sub-scanning is variable.