JPH0469470B2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a film image reading device, and more specifically, a high resolution mode in which the reading pitch is close to a preset laser beam diameter, and a high resolution mode in which the reading pitch is set to a value close to a preset laser beam diameter. The present invention relates to a film image reading device having a normal mode set to be larger than the diameter.

(Prior Art) A so-called film image reading device is known that reads image information recorded on a radiation film or a film on which various images are recorded (hereinafter simply referred to as a film). This type of device includes a drum reading type that fixes image information on photosensitive paper wrapped around a drum, and one that converts image information recorded on film into an analog electrical signal via an optical system such as a laser and lens. However, there is a digital image processing method that samples this data and then converts it into digital data using an A/D converter and performs various image processing.
Among these film image reading devices, multiple resolution modes (e.g. high resolution mode and normal mode)
The only existing device equipped with this is a drum reading system. However, this drum reading method has disadvantages such as slow reading time and poor operability when loading and unloading the film.

(Object of the Invention) The present invention has been made in view of the above points, and its object is to provide a film image processing method using a digital image processing method that has reading modes with a plurality of resolutions and can be read at high speed. To realize a reading device that does not carelessly select a high resolution mode regardless of the capacity of the installed memory.

(Structure of the Invention) The present invention achieves this object by converting image information recorded on a film into an electrical signal through an optical system, sample-holding the analog electrical signal, and then converting it into digital data using an A/D converter. In a film image reading device that performs various image processing by converting the analog image signal into a plurality of images, the first frequency switching means changes the rotational speed of a motor for conveying the film in the winding direction to a plurality of high and low levels; A second frequency switching means that switches between high and low levels in synchronization with the switching of the first frequency switching means, and a signal output that outputs a signal corresponding to the capacity of the memory installed to store image information. and the first and second frequency switching means receives the output signal of the signal output means and prohibits selection of a high resolution mode in which the amount of data to be loaded into the memory exceeds the capacity of the memory. The present invention is characterized by comprising a selection mode regulating means for controlling the means.

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

FIG. 1 is a block diagram showing an embodiment of the present invention, and shows an example of an image reading apparatus for a radiation film recorded with radiation. In the figure, 1 is a laser, 2 is a polygon mirror rotating at a constant speed, and 3 is a laser.
is a first motor that drives the polygon mirror,
The polygon mirror 2 is fixed to the rotating shaft of the motor 3. Reference numeral 4 designates an f/θ lens that receives reflected light from the polygon mirror 2, 5 a radiation film on which image information is recorded, and 6 a second motor that conveys the film 5 in the winding direction (Y direction). As the motor 6, for example, a DC motor with a built-in encoder is used. The light passing through the f/θ lens 4 is
The film 5 is scanned in the X direction (main scanning direction) in the figure, and the second motor 6 transports the film 5 in the Y direction (sub scanning direction) in the figure. 7 is a PLL circuit (Phase Locked Loop circuit) that supplies driving power to the second motor 6 to rotate the motor 6 at a predetermined speed, and the input frequency of the PLL circuit 7 can be set in two high and low levels by the changeover switch SW _1. It is now possible to switch to That is, when the frequency of 2f ₁ is selected, a high-speed pulse is input to the PLL circuit 7, and when the frequency of f ₁ is selected, a low-speed pulse is input to the PLL circuit 7, and the encoder signal (consisting of a pulse train) output from the encoder in the motor 6 is The driving power of the motor 6 is controlled so that the frequency signal (frequency signal) has the same frequency as the input pulse.

An optical fiber 8 is disposed on the opposite side of the film 5 from the f/theta lens 4 and in the main scanning direction, and receives the laser light transmitted through the film 5;
Reference numeral 9 denotes an information converter (such as a photomultiplier tube) that converts the optical signal sent from the optical fiber 8 into an image information signal. The image information recorded on the film is superimposed on the light transmitted through the film 5. Therefore, the information converter 9 extracts only the image information and converts it into an electrical signal. 10 is a logarithmic converter that converts the information signal output of the information converter 9 into a condensed signal;
Reference numeral 11 denotes a sample and hold circuit that samples and holds the output of the logarithmic converter 10 at regular intervals. The sampling frequency of the sample-and-hold circuit 11 can be switched between high and low levels by a changeover switch _SW2 . That is, when the frequency _fA is selected, a low frequency pulse is applied to the sample hold circuit 11, and when the frequency _2fA is selected, a high frequency pulse is applied to the sample hold circuit 11. and the switch SW ₂ and the above-mentioned switch
SW ₁ is designed to be linked, 2f ₁ and f _A , f ₁ and
2f _A are used in pairs. 12 is an A/D converter that converts the hold output of the sample and hold circuit 11 into digital data; 13 is a memory that sequentially stores the output of the A/D converter 12;
14 is a CPU that controls the A/D converter 12 and memory 13 and performs various calculations.

The operation of the device configured in this way is as follows.

When the first motor 3 rotates at a low speed, the motor 3
The polygon mirror 2, whose rotating shaft is fixed to the polygon mirror 2, similarly rotates at a constant speed. As a result, the laser beam emitted from the laser 1 is scanned in the main scanning direction (X direction) of the film 5, and repeats reciprocating motion in the X direction. On the other hand, the second motor 6 moves the film 5
Since the film 5 is conveyed at a constant speed in the sub-scanning direction (Y direction), the laser beam always scans regions at different positions on the film 5 in the X direction. At this time, the transmitted light received by the optical fiber 8 disposed on the back side of the film 5 is a superimposed image of the image recorded on the film 5. The image information superimposed on this transmitted light is transmitted to the information converter 9, where only the image information is extracted and converted into an electrical signal. The image information signal converted here is converted into a signal corresponding to the logarithm of the input in the subsequent logarithmic converter 10. The reason why the logarithmic converter 10 is used in this way is to convert the input image signal into an analog density signal.

Subsequently, the output of the logarithmic converter 10 is sampled and held at regular intervals by a sample and hold circuit 11. The held image signal is
The data is converted into digital data by the A/D converter 12 and sequentially stored in the memory 13. The CPU 14 controls the operation of the A/D converter 12 and controls the storage of data in the memory 13.

In the device of the present invention, both the PLL circuit 7 and the sample hold circuit 11 are provided with frequency switching means for switching the frequency into two levels, high and low. By switching these two frequency switching means in synchronization, it is possible to operate in either the normal mode or the high resolution mode. First, the frequency switching means on the PLL circuit 7 side will be explained. When the changeover switch SW ₁ is connected to the 2f ₁ (high frequency) side, the motor 6 rotates at a high speed and the film 5 is transported at a high speed, and the normal mode is set. On the other hand, the changeover switch
When SW ₁ is connected to the f ₁ (low frequency) side, the motor rotates at a low speed, the film transport speed is slowed down, and a high resolution mode is entered. As mentioned above, in normal mode, the reading pitch is set larger than the laser beam diameter.
In the high resolution mode, the reading pitch is set to a value close to the laser beam diameter. Next, the frequency switching means on the sample and hold circuit 11 side will be explained. When changeover switch SW ₂ is connected to the f _A (low frequency) side, the sampling period slows down and the mode becomes normal mode, and when changeover switch SW ₂ is connected to the 2f _A (high frequency) side, the sampling period slows down and the mode becomes normal mode. Enters resolution mode. Therefore, if the first changeover switch _SW1 and the second changeover switch _SW2 are synchronized and switched at the same time, that is, if switch _SW1 is connected to the _2F1 side, switch _SW2 will be connected to the _fA side. If switch SW ₁ is connected to f ₁ side, switch SW ₂ will be connected to 2 f _A side (high resolution mode), then normal mode will be activated. You can switch between high-resolution and high-resolution modes. These modes can be switched not only by a changeover switch attached to the device as shown in the figure, but also by a command signal from a host computer connected online. Furthermore, the frequencies f ₁ , 2f ₁ , f _A , and 2f _A described above may be generated by an internal device with a generating circuit, or may be input from the outside.

Incidentally, there may be cases where the selected mode and the internal state of the device, for example, the capacity of the built-in memory, do not match. For example, if the built-in memory is for normal mode even though high-resolution mode is selected, there will be an absolute shortage of memory capacity, resulting in the inconvenience of not being able to store all image information. occurs. Therefore, if the internal state of the device and the selected mode do not match,
It is necessary to provide a function that prioritizes the internal state of the device. FIG. 2 is a diagram showing a configuration in which an identification function is added to a printed board (memory board) on which a memory is mounted to achieve this purpose. In the figure, 20, 30
It is assumed that both are compatible memory boards, and the memory board 30 has a capacity four times that of the memory board 20.

A conductive pattern surrounding the memory board 20
Connect _P1 so that it has a potential of 5V and the conductive pattern _P2 surrounding the memory board 30 to a potential of 0V, and connect these patterns to the leftmost terminals of the connector connection parts 21 and 31, respectively. Keep it connected. All other terminals of the connector connection parts 21 and 31 are made compatible. When these memory boards are mounted in such a configuration, an "H" level signal (in the case of the memory board 20) or an "L" level signal (in the case of the memory board 30) is output from the leftmost terminal. ) is output, so
By detecting this signal, the internal state of the device can be known. In other words, when the "H" signal is output, it means that a normal memory board is being used, and conversely, when the "L" signal is output, it means that a memory board with four times the capacity is being used. .
Note that the other terminals of the memory boards 20 and 30 are made compatible and can be used interchangeably. Further, the detection terminal is not necessarily limited to the left end of the connector connection portion, and may be located at any position.

FIG. 3 is a diagram showing an embodiment of a circuit that uses this detection signal to give priority to the internal state of the device. In the figure, D ₁ is a signal output from the memory board mentioned above to detect the internal state of the device (hereinafter referred to as a detection signal), and D ₂ is an external selection signal indicating normal mode or high resolution mode, which is the same as mentioned above. This is the switching signal for the switching switches SW ₁ and SW ₂ . When the detection signal _D1 is "H", the internal state indicates that a normal capacity memory is installed, and when it is "L", it indicates that a quadruple capacity memory is installed. Further, when the switching signal _D2 is "H", it indicates the normal mode, and when it is "L", it indicates the high resolution mode. The D ₁ signal enters one input of OR gate 41 and inverter 42 , and the D ₂ signal enters one input of AND gate 43 . The output of inverter 42 enters the other input of AND gate 43, which in turn enters the other input of OR gate 41. The output of the OR gate 41 is a (normal/high resolution) selection signal _E1 , and the output of the inverter 42 is a high resolution mode selectable signal.
Functions as _E2 . These E ₁ or E ₂ signals are
It is read by the CPU 14 (see FIG. 1).
When E ₁ is "H", it indicates the normal mode, when it is "L", it indicates the high resolution mode, and when E ₂ is "H", it indicates that the high resolution mode can be selected.
The operation of the circuit configured in this way will be explained.

When D ₁ is “H” and D ₂ is also “H”, the (normal/high resolution) selection signal E ₁ becomes “H” and the normal mode is switched.
The high resolution selectable signal _E2 becomes "L", indicating that the high resolution mode cannot be selected. Next, if D ₁ is “L” and D ₂ is also “L”, the (normal/high resolution) selection signal E ₁ “L”
High resolution mode, high resolution selectable signal E ₂
becomes "H", indicating that high resolution mode can be selected. There is no problem if the selection signal from the outside and the internal detection signal match as described above. The problem occurs when the internal detection signal _D1 indicates the normal mode even though the external switching signal _D2 selects the high resolution mode. In this case, D ₁ is “H”, D ₂
becomes "L", the (normal/high resolution) selection signal E ₁ becomes "H", indicating high resolution mode, but the high resolution selection signal E ₂ becomes "L", indicating high resolution mode. Informs you that selection is not possible. Therefore, the CPU 14 sets the mode to normal mode. That is, the changeover switch SW ₁ ,
Switch SW ₂ to normal mode at the same time. In this way, settings can be made according to the internal state of the device.

In the above description, the rotational speed of the motor for transporting the film and the sampling frequency are simultaneously switched between two high and low levels. However, the following methods may also be used.

(1) Set the film transport speed and sampling frequency according to the conditions of the high-resolution mode, and select the high-resolution mode and the normal mode by thinning out and reading each line in the case of the normal mode.

(2) Set the sampling frequency according to the conditions of high resolution mode, set the film transport speed to two types, high resolution and normal, and select the normal transport speed for normal mode. Read by thinning out each pixel.

(3) Set the transport speed according to the conditions of high-resolution mode, set the sampling frequency to two types: high-resolution and normal, and set the sampling frequency for normal in normal mode, and set the sampling frequency for 1 line. Every pixel is thinned out and all pixels are read.

(Effects of the Invention) As described in detail above, according to the present invention, there is provided a first frequency switching means for switching the rotational speed of the motor for transporting the film in the winding direction into two high and low levels, and a first frequency switching means for sampling an analog image signal. It is equipped with a second frequency switching means for switching the sampling frequency into two high and low steps, and by switching these to the low speed side or the high speed side at the same time, the normal mode and the high resolution mode (this is not limited to one type. By increasing the number of switches of the second switching means, two or more high resolution modes can be selected. Therefore, according to the present invention, high-speed reading is possible, and a mode in which a desired film region can be read with high resolution can be selected, providing a high degree of flexibility in image diagnosis. Also, since it is not a drum type, it has excellent film handling properties. Furthermore, if a high-resolution mode cannot be selected due to the installed memory capacity, the selection of that resolution mode is automatically prohibited, making it impossible to carelessly select a high-resolution mode without regard to the memory capacity. Therefore, it is possible to realize a device with excellent operability.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a configuration diagram of a memory board used in the device of the present invention.
FIG. 3 is a circuit diagram showing an embodiment of a circuit that gives priority to the internal state of the device. 1...Laser, 2...Polygon mirror, 3,6
...Motor, 4...F/θ lens, 5...Radiation film, 7...PLL circuit, 8...Optical fiber,
9... Information converter, 10... Logarithmic converter, 11...
...Sample hold circuit, 12...A/D converter, 13...Memory, 14...CPU, 20,3
0... Memory board, 21, 31... Connector connection section, 41... OR gate, 42... Inverter, 43... AND gate, SW ₁ , SW ₂ ... Changeover switch, P ₁ , P ₂ ... Conductive pattern .

Claims (1)

[Claims] 1. In a film image reading device that converts image information recorded on a film into an electrical signal via an optical system, samples and holds the analog electrical signal, and then converts it into digital data using an A/D converter and performs various image processing. , a first frequency switching means for switching the rotational speed of a motor for conveying the film in the winding direction to a plurality of high and low levels;
a second frequency switching means for switching between high and low levels in synchronization with the switching of the frequency switching means; and a signal outputting means for outputting a signal according to the capacity of the memory installed to store the image information. , receiving the output signal of the signal outputting means, the first and second frequency switching means are configured to prohibit selection of a high resolution mode in which the amount of data to be loaded into the memory exceeds the capacity of the memory; A film image reading device comprising a selection mode regulating means for controlling.