JPH04329060A - Portable picture reader - Google Patents

Abstract

PURPOSE:To attain variable setting of a production period of a subscanning synchronizing signal by selecting a detection signal with a different period generated from plural moving detection means as the subscanning synchronizing signal. CONSTITUTION:Two encoder disks 61, 62 driven around a shaft 38 are used and each of them is provided with a photo interrupter 63, 64 detecting a slit. In this case, the interval of slits of the disk 61 is decided so that 8 slits of the encoder disk 61 are detected as to movement of a scanner by 1mm. Moreover, the slit interval of the other encoder disk 62 is set twice the slit interval of the encoder disk 61 and four slits are detected by movement of a scanner by 1mm. Then synchronizing signals generated by the two encoders 61, 62 and the photo interrupters 63, 64 are selected or synthesized to generate various subscanning synchronizing signals. That is, any of the detection signals is used as the subscanning synchronizing signal and selected and outputted in response to an external selection command signal.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable image reading device that reads an image of a document by moving the main body of the device, and more particularly to a portable image reading device that reads images in the sub-scanning direction when manually driven by an operator. .

0002

[Prior Art] In recent years, portable image reading devices (handy scanners) have been commercialized that can easily read images from documents in order to incorporate images such as illustrations into documents created using word processors, personal computers, etc. ing.

A handy scanner generally has a shape as shown in FIG. 18, and a one-dimensional line sensor is usually used as a reading sensor. In such a handy scanner, movement in the sub-scanning direction is carried out by holding the housing 20 of the handy scanner shown in FIG. Move it in the direction of the arrow. The operator also traces the document image to read it in the sub-scanning direction using the handy scanner.

The speed of movement in the sub-scanning direction varies depending on the operator who performs the reading, and the speed during movement may also not be constant. Therefore, such a handy scanner is equipped with a scanner that comes in close contact with the document 39, as shown in FIG. An encoder plate 31 and an encoder plate 3 having evenly cut slits rotate according to the rotation of a guide roller 30 that rotates.
A photo interrupter 32 is provided to detect one slit.

In the figure, 33, 34, and 35 are gears that are fitted into each other as shown in the figure, and are connected to main shafts 36, 37, and 38, respectively.
Rotate around.

As clearly shown in FIG. 19, the guide roller 30
The main shaft of is the shaft 36, and the main shaft of the encoder plate 31 is the shaft 38, so the gear 33 rotates according to the rotation of the guide roller 30, the gear 35 rotates via the gear 34, and the encoder plate 31 rotates.

In this case, for example, if the handy scanner has a resolution of 8 pels (outputs data of 8 dots per 1 mm width), the slit of the encoder plate 31 will be scanned 8 times by the photo interrupter 32 when the scanner moves 1 mm. The slits are cut so that slit detection is performed.

[0008] The external device inputting the detection signal and the image signal is controlled so that one line of data from the line sensor 25 immediately after the slit detection is made valid data. The line sensor 25 is set so that an image of the document 39 illuminated by the light source 22 is formed through the mirror 23 and the lens 24 .

[0009] The CCD line sensor 25 is located at a distance of 1 m above the original.
Since the position is set so that m corresponds to 8 pixels on the line sensor, reading can be performed with a resolution of 8 pels in both main scanning and sub-scanning.

One of the additional functions required of such a handy scanner is a variable magnification function. In other words, it has the function of reducing or enlarging a desired original image and storing the data or printing it out.

[0011] Although this variable magnification function can be provided on the host side such as a word processor to which the handy scanner is connected,
Since this function is unnecessary for users who have scanners that do not have a variable magnification function, it is common practice to provide this function on the scanner side and accept data using the same interface format on the host side no matter which scanner is connected. It's being targeted.

0012

However, in such a handy scanner, assuming that high-magnification image reading is required, the slit spacing of the encoder plate described above must be made small. For example, 150
If a magnification ratio of % is required, the slit interval on the encoder plate is 100/150 = 2/3 when reading a 100% image.
However, if the diameter of the encoder plate is small, it is technically difficult to cut slits at a fine pitch. Further, even if the slit is cut, the width of the encoder plate blocking light from the photointerrupter becomes narrower, so the light receiving section of the photointerrupter cannot be completely blocked, and the photointerrupter may no longer generate pulses.

[0013] For this reason, the diameter of the encoder plate is reduced to 100%.
One possible method is to make the slit interval 100% the same as when reading an image by increasing 3/2 = 1.5 times when reading an image, but the outer size of the housing that houses the encoder plate becomes larger, and the handheld scanner aims to be smaller and lighter. It is not suitable for

Furthermore, it is possible to obtain a desired pulse output by changing the gear ratio as shown in FIG. , encoder plate 3
1 has a diameter of about 15 mm to 20 mm. The magnification ratio is 1
If it is 00%, the gear ratio of gear 33 and gear 35 is approximately 2:
1, the diameter of gear 35 is at most 7.
It will only be about mm. In order to realize a handy scanner with a magnification ratio of 150%, the diameter of the gear 35 is calculated to be 5 mm or less, and it is technically difficult to create such a gear.

Alternatively, it is possible to increase the diameter of the gear 33 by 1.5 times, but inevitably the diameter of the guide roller 30 also becomes approximately 1.5 times, which is still unsuitable for a handheld scanner that aims to be smaller and lighter. You can say that.

SUMMARY OF THE INVENTION In view of the above-mentioned points, an object of the present invention is to provide a portable image reading device that can generate various sub-scanning synchronization signals using a conventional encoder board. do.

[0017]

[Means for Solving the Problems] In order to achieve such an object, a first aspect of the present invention provides a movement detecting means provided in a moving means for moving the apparatus main body by self-propelled or manual means. In a portable image reading device that detects a fixed amount of movement of the main body and generates a sub-scanning synchronization signal based on the detection signal, a plurality of movement detection means having different generation cycles of the detection signal are provided, and the plurality of movement detection means are provided. It is characterized by comprising a control means for selectively outputting one of the detection signals of the means as the sub-scanning synchronization signal in response to an external selection instruction signal.

A second aspect of the present invention is to detect a fixed amount of movement of the device body in a movement detecting means provided in a moving means for moving the device body by self-propelled or manual movement,
In a portable image reading device that generates a sub-scanning synchronization signal based on the detection signal, a plurality of movement detection means having different generation cycles of the detection signal are provided, and the detection signals of the plurality of movement detection means are combined. The present invention is characterized by comprising a signal processing means for creating a sub-scanning synchronization signal.

A third aspect of the present invention is to detect a fixed amount of movement of the device main body in a movement detection means provided in a moving means for moving the device main body by self-propelled or manual movement,
In a portable image reading device that generates a sub-scanning synchronization signal based on the detection signal, a plurality of the movement detection means having different generation cycles of the detection signals are provided, and a second signal is provided to synthesize the detection signals of the plurality of movement detection means. processing means, any one of the detection signals of the plurality of movement detection means and the signal synthesized by the second signal processing means as the sub-scanning synchronization signal in response to an external selection instruction signal; The present invention is characterized by comprising a second control means for selectively outputting.

[0020] A fourth aspect of the present invention is to detect a fixed amount of movement of the apparatus main body in a movement detection means provided in a moving means for moving the apparatus main body by itself or manually,
In a portable image reading device that generates a sub-scanning synchronization signal based on the detection signal, a plurality of the movement detection means having different generation cycles of the detection signals are provided, and a second signal is provided to synthesize the detection signals of the plurality of movement detection means. a processing means, a second movement detection means that generates a second detection signal having the same generation cycle and a different phase as the detection signal of a specific movement detection means among the plurality of movement detection means, and the specific movement detection means. and a third signal processing means for synthesizing the detection signal of the plurality of movement detection means and the second detection signal of the second movement detection means, the detection signal of the plurality of movement detection means, the signal synthesized by the second signal processing means and the third signal processing means. The present invention is characterized by comprising third control means for selectively outputting one of the signals synthesized by the signal processing means as the sub-scanning synchronization signal in response to an external selection instruction signal.

A fifth aspect of the present invention is a third control means for configurably setting the reading timing of the image signal in the main scanning direction in correspondence with the selection instruction signal in the first, third, and fourth aspects. It is characterized by further comprising the following.

[0022]

In the first embodiment of the present invention, the generation cycle of the sub-scanning synchronizing signal is variably set by selecting detection signals having different cycles generated by a plurality of movement detecting means as the sub-scanning synchronizing signal.

In the second embodiment of the present invention, a sub-scanning synchronization signal with a shorter period than the conventional one can be created by combining a plurality of detection signals with different periods, and the conventional movement detecting means can be used as is. .

In a third embodiment of the present invention, the generation period of the sub-scanning synchronizing signal is variably set by using each detection signal of the movement detecting means or a combined signal as the sub-scanning synchronizing signal.

A fourth aspect of the present invention is to provide a (second) movement detection means for generating a (second) detection signal out of phase with respect to the detection signal of a specific movement detection means, and to By combining the sub-scanning synchronization signals, the types of cycles of the sub-scanning synchronization signals are diversified.

In the fifth embodiment of the present invention, images for reduction and enlargement can be obtained by making the image reading timing in the main scanning direction variable in accordance with the generation cycle of the sub-scanning synchronizing signal.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an embodiment of the present invention will be described in detail below with reference to the drawings.

The mechanical structure of the handy scanner embodying the present invention is similar to the structure shown in FIG. 19 described above. Therefore, the differences between the present invention and the conventional example will be explained.

Gear 35, shaft 38 and two encoder plates 6
FIG. 2 is a simplified external view showing the positional relationship between photointerrupters 1 and 62 and two photointerrupters 63 and 64.

In this embodiment, as shown in FIG. 2, there are two encoder plates rotating about the shaft 38, each of which is provided with photointerrupters 63 and 64 for detecting slits. The slit spacing of the encoder plate 61 is set so that eight slits are detected per 1 mm of movement of the scanner. In other words, it is equivalent to an encoder plate used in a handy scanner with a resolution of 8 pels. The slit interval on one encoder plate 62 is set to twice the slit interval on the other encoder plate 61. That is, the setting is such that four slits are detected per 1 mm of movement of the scanner.

FIG. 3 shows the circuit configuration of a handy scanner embodying the present invention.

In FIG. 3, 25 is a CCD run sensor;
402 is an analog amplifier, and 403 is an A/D converter that converts an analog signal into a digital signal. 404
shows a sample hold circuit that samples and holds the digital signal output from the A/D converter 403 at the timing of an externally input clock.

405 is a binarization circuit, 406 is a sub-scanning synchronization signal generation circuit for generating a sub-scanning synchronization signal for the handy scanner, and 407 is a pulse generator for generating the operation clock necessary to operate each electric block. .

Regarding the handy scanner having the above configuration, the operation of each block will first be explained when reading 8 pels.

[0035] The CCD 2 is set so that the number of sensor pixels corresponding to 1 mm on the original is 8 pixels (8 pels).
The analog image signal outputted from 5 is amplified by an analog amplifier 402, and converted to an 8-bit digital signal by an A/D converter 403.

The digital image signal read in 8 pels is sampled by a sample hold circuit 404, and the data is held until the next sample is performed. The sample timing is determined by the pulse generator 407.
Determined by the sample clock S-CLK output from the. The output timing of the sample clock S-CLK is changed depending on the desired reading magnification ratio.

The image data sampled by the sample and hold circuit 404 is input to a binarization circuit 405, and after various image processing is performed, it is compared with preset 8-bit slice level data and binarized. being done,
Data synchronization signal S-S as 1-bit image data VD
It is output to an external device (not shown) together with YNC. Signal VD
The output states of various S-SNYCs are shown in FIGS. 4 to 6. As can be seen from FIGS. 4 to 6, VD is controlled to change at the rise of S-SYNC.

Next, the sub-scanning synchronization signal generation circuit 406 according to the present invention will be explained.

FIG. 1 shows an electrical block configuration of sub-scanning synchronization signal generation circuit 406.

In the figure, 63 and 64 are the first photointerrupter and the second photointerrupter in FIG. 2, respectively. 13 and 14 are TTL level conversion circuits that convert the output signal of the photointerrupter into a control signal level. Reference numeral 15 denotes a gate circuit, which is composed of AND gates 16 and 17 and an XOR gate 18. A truth table of AND gates 15, 16 and XOR gate 17 is shown in FIG.

FIG. 8 shows the output waveforms of the photointerrupters 63 and 64 and the output waveforms of the TTL level conversion circuits 13 and 14 when the encoder plates 61 and 62 are rotating at a constant speed.

First, the circuit operation for 100% image reading will be explained.

The sampling clock SCLK shown in FIG. 9 is used as the sampling clock for input data in the main scanning direction when reading at 100%.

For this reason, the sample hold circuit 4 in FIG.
Since data sampling in 04 is performed for each pixel in the main scanning direction, the image data output from the sample hold circuit 404 is 8 pel image data. That is, a scanner with a resolution of 8 pels in standard reading corresponds to 100% image reading.

In order to synthesize the sub-scanning synchronizing signal for 100% image reading, the selection signal SEL1 input to the AND gate 16 in FIG. 1 is set to bit "1", and the AND gate 17
The selection signal SEL2 inputted to the input terminal is set to bit "0". At this time, according to the truth table of FIG. 7, the sub-scanning synchronization signal F-SYNC output from the XOR gate 18 is TT
Regardless of the output state of the L level conversion circuit 14, the output of the TTL level conversion circuit 13 is output as is.

As a result, a sub-scanning synchronization signal adapted to the 100% magnification ratio is also output to the external device in the sub-scanning direction at the same time as the image signal. An external device (not shown) detects the rising edge of the sub-scanning synchronization signal and controls the data of one line of the CCD line sensor 25 immediately after that to be valid.

Next, a case will be described in which 150% image reading is performed.

When performing 150% image reading, FIG.
The output timing of the sample clock S-CLK generated from the pulse generator 407 is switched to the timing shown in FIG. This sample clock S-CLK
As shown in FIG. 10, the sample and hold circuit 404 samples the digital data output from the A/D converter 403 three times for every two outputs. Therefore, 150% variable magnification image reading is performed in the main scanning direction. Image data VD and data synchronization signal S-SY at this time
The output state of the NC is shown in FIG.

Next, the operation of generating the sub-scanning synchronizing signal during 150% reading will be explained.

In this case, the selection signal SEL1 input to the AND gate 16 in FIG. 1 is set to bit "1", and the selection signal SEL2 input to the AND gate 17 is set to bit "1".
According to the truth table of FIG.
The output signal F-SYNC of No. 8 is as shown in FIG.

That is, the XOR gate 18 within a certain period of time
The number of output pulses is 1.5 times that of 100% image reading. As a result, the sub-scanning synchronization signal F-SYNC corresponding to the 150% magnification ratio is output to an external device (not shown) simultaneously with the image data VD, etc. (see FIG. 3).

Finally, a case will be described in which 50% image reading is performed.

In this case, the pulse generator 40 of FIG.
The output timing of the sample clock S-CLK generated from 7 is switched to the timing shown in FIG. As shown in FIG. 11, the sample hold circuit 404
The digital data output from the converter 403 is
Sample once per output. Therefore, 50 in the main scanning direction
% variable magnification image reading will be performed.

FIG. 6 shows the output states of the image data VD and data synchronization signal S-SYNC at this time.

Next, the operation of generating the sub-scanning synchronizing signal during 50% reading will be explained.

In this case, the selection signal SEL1 input to the AND gate 16 in FIG. 1 is set to bit "0", and the selection signal SEL2 input to the AND gate 17 is set to bit "1".
At this time, according to the truth table of FIG. 7, the sub-scanning synchronization signal F-SYNC output from the XOR gate 18 is
The output of the TTL level conversion circuit 14 is output as is. As a result, in the sub-scanning direction, a sub-scanning synchronization signal adapted to a magnification of 50% is output from the sub-scanning synchronization signal generation circuit 406 of FIG. 3 to an external device simultaneously with the image signal.

The data synchronization signal S-SYNC, the magnified image data VD, the sub-scanning synchronization signal F-SYNC according to the magnification ratio, etc. output in this way are output as the data synchronization signal S-SYNC in an external device (not shown). Image data VD is taken in according to SYNC, valid data is selected according to the timing of sub-scanning synchronization signal F-SYNC, and the image is reproduced by an image output device such as a printer or stored in a memory such as a hard disk.

As explained above, in this embodiment, two sets of slit detection sections each consisting of an encoder plate and a photointerrupter are set, and a gate circuit is used to selectively output or combine signals generated from the slit detection sections. Equipped with. As a result, even if an encoder plate having slits cut at a coarse pitch is used, it is possible to read an image with high magnification processing.

In addition to this embodiment, the following examples can be given.

1) In this embodiment, a configuration in which two sets of sub-scanning movement amount detecting means (encoder plates 61 and 62) are installed has been described, but a sub-scanning movement amount detecting means (encoder plates 61 and 62) is installed. The scanning movement amount detection means is 3
Can also be used in pairs.

In this case, the slit position of the new encoder plate is set to an intermediate position between the slit positions of the encoder plate 61. Furthermore, by configuring the sub-scanning synchronization signal generation circuit as shown in FIG. 13, 200% enlarged reading is possible. The circuit configuration of FIG. 13 and the procedure for 200% enlarged reading will be described below.

In FIG. 13, the same members as those described above are designated by the same numbers. 100 and 101 are a newly provided photointerrupter and a TTL level conversion circuit, respectively. 102 is a selector, and a selection signal SE
One or two of the three input sub-scanning synchronization signals are selected by the logic of L1 and SEL2.

The photointerrupter 100 detects a slit in an encoder plate (not shown) having the same shape as the encoder plate 61 in FIG. 2, but has the same period and phase as shown in FIG. The slit position is set so that the output is shifted. The output of the TTL level conversion circuit 101 with respect to the output of the photointerrupter 100 is also shown in FIG.

When performing 200% image reading, FIG.
The output timing of the sample clock S-CLK generated from the pulse generator 407 is switched to the timing shown in FIG. That is, the sample hold circuit 404 is connected to the A/D converter 403 as shown in FIG.
The digital data output from is sampled twice for each output. Therefore, 200% variable magnification image reading is performed in the main scanning direction. Next, a procedure for generating a sub-scanning synchronizing signal during 200% reading will be explained.

In this case, the selection signal SEL1 input to the selector 102 in FIG. 13 is set to bit "0", and the selection signal SEL2
Set the bit to “0”. This selection signal selector 1
The signal selected by 02 is the TTL level conversion circuit 1.
3 and the output signal of the TTL level conversion circuit 101. X
Sub-scanning synchronization signal F-SY output from OR gate 18
According to the truth table of FIG. 7, the NC has an output waveform shown in FIG. 16. That is, in the sub-scanning direction, a sub-scanning synchronization signal adapted to a magnification of 200% is output to the external device simultaneously with the image signal.

Of course, the sub-scanning synchronizing signal generating circuit having the circuit configuration of FIG. 13 is also capable of variable magnification reading of 50%, 100%, and 150%, similar to the sub-scanning synchronizing signal generating circuit having the circuit configuration of FIG. FIG. 17 shows the correspondence between the scaling factors selected depending on the bit states of the selection signals SEL1 and SEL2.

[0067]

[Effects of the Invention] As explained above, according to the present invention,
Since a single synchronization signal generator can generate a sub-scanning synchronization signal with a larger number of output pulses than in the past, which generates the sub-scanning synchronization signal by itself, the reading resolution can be improved without using particularly large parts. It is possible to construct a hand-driven handheld scanner that is variable and can read at variable magnification.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of a sub-scanning synchronization signal generation circuit according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the main structure of the movement detection means according to the embodiment of the present invention.

FIG. 3 is a block diagram showing a circuit configuration of an embodiment of the present invention.

FIG. 4 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 5 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 6 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing the relationship between input signals and output signals of the gate circuit in FIG. 1;

FIG. 8 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 9 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 10 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 11 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 12 is a waveform diagram showing signal generation timing in the embodiment of the present invention.

FIG. 13 is a block diagram showing a circuit configuration of another embodiment of the present invention.

FIG. 14 is a waveform diagram showing signal generation timing in another embodiment of the present invention.

FIG. 15 is a waveform diagram showing signal generation timing in another embodiment of the present invention.

FIG. 16 is a waveform diagram showing signal generation timing in another embodiment of the present invention.

FIG. 17 is an explanatory diagram showing the relationship between the bit contents of the selection signal and the scaling factor in another embodiment of the present invention.

FIG. 18 is a perspective view showing the appearance of a conventional example.

FIG. 19 is a sectional view showing a main side sectional structure of a conventional example.

[Explanation of symbols]

13, 14 TTL level conversion circuit 15 Gate circuit 16-17 AND gate 18 XOR gate 20 Housing 25 CCD line sensor 30 Guide roller 31 Encoder board 32 Photo interrupter 33, 34, 35 gear 36, 37, 38 axis 39 Manuscript 61, 62 Encoder board 63, 64 Photo interrupter 402 Analog amplifier 403 A/D converter 404 Sample hold circuit 405 Binarization circuit 406 Sub-scanning synchronization signal generation circuit 407 Pulse generator

Claims (5)

[Claims] Claim 1: A mobile phone, in which a movement detecting means provided in a moving means for moving the device main body by self-propelled or manual means detects a certain amount of movement of the device main body, and generates a sub-scanning synchronization signal based on the detection signal. In the type image reading device, a plurality of the movement detection means having different generation cycles of the detection signals are provided, and one of the detection signals of the plurality of movement detection means is selected as the sub-scanning synchronization signal from the outside. 1. A portable image reading device comprising: a control means for selectively outputting an output according to an instruction signal. [Claim 2] A mobile device in which a movement detecting means provided on a moving means for moving the device main body by self-propelled or manual means detects a certain amount of movement of the device main body, and generates a sub-scanning synchronization signal based on the detection signal. In the type image reading device, a plurality of the movement detection means having different generation cycles of the detection signals are provided, and a signal processing means creates the sub-scanning synchronization signal by combining the detection signals of the plurality of movement detection means. A portable image reading device characterized by: 3. A mobile device in which a movement detecting means provided in a moving means for moving the device main body either self-propelled or manually detects a certain amount of movement of the device main body, and generates a sub-scanning synchronization signal based on the detection signal. In the type image reading device, a plurality of the movement detection means having different generation cycles of the detection signals are provided, a second signal processing means for synthesizing the detection signals of the plurality of movement detection means, and a detection of the plurality of movement detection means. and a second control means for selectively outputting any one of the signal and the signal synthesized by the second signal processing means as the sub-scanning synchronization signal in response to an external selection instruction signal. A portable image reading device characterized by: 4. A mobile device in which a movement detecting means provided on a moving means for moving the device main body by self-propelled or manual means detects a certain amount of movement of the device main body, and generates a sub-scanning synchronization signal based on the detection signal. In the type image reading device, a plurality of the movement detection means having different generation cycles of the detection signals are provided, a second signal processing means for synthesizing the detection signals of the plurality of movement detection means, and a second signal processing means among the plurality of movement detection means. a second movement detection means that generates a second detection signal having the same generation period and a different phase from the detection signal of the specific movement detection means;
a third signal processing means for synthesizing the second detection signals of the movement detection means; a signal synthesized by the detection signals of the plurality of movement detection means, a signal synthesized by the second signal processing means, and a signal synthesized by the third signal processing means; A portable image reading device comprising: third control means for selectively outputting one of the signals as the sub-scanning synchronization signal in response to an external selection instruction signal. 5. The image forming apparatus according to claim 1, further comprising third control means for configurably setting the reading timing of the image signal in the main scanning direction in response to the selection instruction signal.
The portable image reading device according to claim 3 or 4.