JPH11312212A - Symbol reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the power consumption of a symbol illumination means and also to reduce the spaces which are occupied by the symbol illumination means and a target illumination means by setting the lighting periods of the symbol illumination means to the same duration as the exposure periods of the image-pickup devices. SOLUTION: The lighting periods of symbol illumination parts 32 and 34 are set to the same duration of the exposure periods of an area sensor 36 and a linear sensor 37 respectively. In such a constitution of a symbol reader, the parts 32 and 34 are turned off, and the exposure periods of the sensors 36 and 37 are also turned off in a period t1, when the beam spot LED 34 and 35 are turned on. Meanwhile, the parts 32 and 34 and the sensors 36 and 37 are turned on in a period t2, when the LED 34 and 35 are turned off. In other words, the parts 32 and 34 are illuminated only during the exposure periods of sensors 36 and 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an image sensor comprising a photoelectric conversion element which irradiates a symbol on a print medium with light and outputs an electric quantity corresponding to an amount of light received from the symbol. A symbol reading device.

[0002]

2. Description of the Related Art Handy type symbol information provided with an image sensor constituted by a photoelectric conversion element which irradiates a symbol on a print medium with light and outputs an electric quantity corresponding to an amount of light reflected from the symbol. An LED (light emitting diode) is used as a light source for illumination of the reader.

Such a light source irradiates a spot light as a target to a substantially central portion of a reading range of an image pickup means by a target illuminating means, and a handy type symbol information reading apparatus so that a symbol comes to a focal point of the image pickup means. The symbol is illuminated by symbol illuminating means for illuminating the symbol, and the reflected light is imaged by the imaging means.

[0004]

When reading a symbol with such a symbol information reading apparatus, operating the target turns off the target lighting means and turns on the symbol lighting means for lighting the symbol. When the symbol is turned on by the symbol lighting means, the light reflected from the symbol is incident on the image pickup means, and an image of the symbol is picked up.

After the symbol image is decoded, the target lighting means is turned on again.

However, there is a problem that power consumption increases because the illumination time for the symbol by the symbol illumination means is much longer than the exposure time of the imaging means.

Further, since the symbol illuminating means and the target illuminating means are respectively constituted by dedicated parts, there is a problem that the space occupied by the symbol illuminating means and the target illuminating means becomes large.

Further, when illumination from the target illumination means is incident on the image pickup means, there is a problem that the symbol image picked up by the image pickup means is affected.

The present invention has been made in view of the above points, and an object of the present invention is to irradiate a symbol on a print medium with light,
In a symbol reading device provided with an image sensor constituted by a photoelectric conversion element for outputting an electric quantity corresponding to an amount of light reflected from the symbol, power consumption of an illuminating means for illuminating the symbol is minimized, and a symbol illuminating means is provided. And minimize the space occupied by the target lighting means,
In addition, it is an object of the present invention to provide a symbol reading device in which illumination from a target illumination unit is incident on an imaging unit and does not affect a symbol image captured by the imaging unit.

[0010]

According to a first aspect of the present invention, there is provided a symbol reading device for irradiating a symbol on a print medium with light and outputting an amount of electricity corresponding to the amount of light received from the symbol. In a symbol reading device provided with imaging means constituted by: a symbol illuminating means for irradiating the symbol with light, a target illuminating means for irradiating a spot light as a target to a substantially central portion of a reading range of the imaging means, An illumination control unit for turning off the target illumination unit during the exposure period of the imaging unit and setting the illumination period of the illumination unit and the exposure period of the imaging unit to be the same. According to a second aspect of the present invention, there is provided a symbol reading device, comprising: an imaging unit configured to irradiate a symbol on a print medium with light and output a quantity of electricity corresponding to an amount of received light reflected from the symbol. The symbol reading device is characterized in that the symbol illuminating means for irradiating the symbol and the target illuminating means for irradiating spot light as a target to the center of the reading range of the imaging means are the same general illuminating means.

According to a third aspect of the present invention, there is provided a symbol reading device, wherein the general lighting means uses the general lighting means as a target lighting means, and uses the general lighting means as a symbol lighting means. Wherein the brightness is changed.

According to a fourth aspect of the present invention, there is provided a symbol reading device, comprising: a photoelectric conversion element configured to irradiate a symbol on a print medium with light and to output an electric quantity corresponding to an amount of light received from the symbol. In the symbol reading device comprising: a general lighting means using a part of the light of the symbol lighting means for irradiating the symbol as target lighting means for irradiating a spot light as a target to the center of the reading range of the imaging means; It is characterized by having.

According to a fifth aspect of the present invention, there is provided a symbol reading device according to the fourth aspect, wherein the general illuminating means uses the general illuminating means as a target illuminating means and uses the general illuminating means as a symbol illuminating means. Wherein the brightness is changed.

According to a sixth aspect of the present invention, there is provided a symbol reading device, comprising: a photoelectric conversion element configured to irradiate a symbol on a print medium with light and to output an electric quantity corresponding to an amount of light received from the symbol. A target illuminating means for irradiating a spot light to a substantially central portion of a reading range of the imaging means as a target, and a first polarized light disposed between the target illuminating means and the symbol. Means, and a second polarizing means disposed between the symbol and the imaging means, wherein the polarization direction of the first polarizing means and the polarization direction of the second polarizing means are orthogonal to each other. It is characterized by having.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an overview of two types of handy scanners to which the present invention is applied will be described.

FIG. 1 is a perspective view showing a hand-held touch type (contact type) code scanner 1 to which the present invention is applied.

An interface cable 3 is connected to the apparatus main body 2. This interface cable 3
The apparatus main body 2 is connected to an apparatus for processing code data such as a host computer (not shown). In addition to the communication through the interface cable 3, communication means such as wireless communication and infrared communication can be selected and used.

The body cases 2a, 2b of the apparatus main body 2
As shown in FIG. 2, the housing is made of a plastic material or the like, and has a hollow structure in which a vertically divided housing is integrally formed by fitting or screwing, and has a dustproof and drip-proof structure.

As shown in FIG. 3, a trigger switch 4 is provided on the side of the apparatus main body 2 so that an operator can instruct a reading timing when reading a code.
A display device (for example, LED = light emitting) for displaying the status such as reading completion or reading error by changing the display method (blinking cycle, lighting time, etc.) on the upper surface of the device.
diode) 5 is arranged.

The trigger switch 4 malfunctions (ON operation) even when the apparatus main body 2 falls down or falls down.
To avoid this, the portion of the side of the device main body 3 where the trigger switch 4 is arranged is formed in a concave shape and is housed inside the outer contour line of the device main body 3.

In the apparatus main body 2, a reading port 6 having an opening for reading is constituted by combining two kinds of materials, a hard material and a soft material. That is, as shown in FIG. 4, a hood (cone = cone-shaped member) 7 made of a soft material is attached near the reading port 6, and
Is composed of the body cases 2a and 2b made of a hard material. This is a structure for absorbing a shock caused by contact with a print medium to be read and preventing damage due to the shock.

The shape of the hood 7 is basically conical and has an opening having a small opening area at one end and an opening having a small opening area at the other end.
It is easily and detachably mounted.

As shown in FIG. 5A, by incorporating a lens 7a in the detachable hood 7, the reading magnification and the like can be arbitrarily changed.

The symbol (bar code, two-dimensional code) can be smoothly read by setting the shape of the opening end of the reading port 6 in contact with the print medium of the hood 7 to be the same as the reading range by an image reading sensor described later. Can be accommodated within range.

As shown in FIG. 5B, a rib 7 for correcting the strength is provided at a position (center position) corresponding to the hood 7.
By providing b, the center of the reading range can be easily visually identified. The hood 7 has the above-described function, and realizes an effect of preventing an image from running out.

As shown in FIG. 5 (c), the tip of the hood 7 which comes into contact with the print medium has an R corresponding to the center of the reading range.
By forming the concave portion 7c having a shape, even when reading a symbol printed on a cylindrical or spherical surface, rolling of a cylindrical or spherical print medium can be prevented, and stable reading can be realized.

When the hood 7 is made translucent, the reading state of the symbol to be read can be directly visually confirmed through the hood 7, so that the symbol is touched so as to enter the reading range (field of view) of the code scanner 1. The positioning operation of the expression code scanner 1 can be performed.

A portion of the body cases 2a and 2b opposite to the reading port 6 with respect to the trigger switch 4 is a grip portion which can be gripped by an operator with one hand so that the vicinity of the trigger switch 4 is narrowed, and a thumb and an index finger are used. To have an appropriate size to hold. Then, the width of the palm increases toward the direction of the little finger in the direction of the little finger, and the shape is such that a smooth projection is formed on the little finger portion.

This allows the trigger switch 4 to be operated naturally with the index finger when the grip portion is gripped by hand.

The angle formed by the central axis of the grip and the central axis of the reading port 6 is at least greater than 90 °.
It is formed so as to be 0 ° or less.

The positional relationship between the grip portion and the reading opening 6 (hood 7) is such that when the grip portion is gripped, the reading opening 6 (hood 7) is present on the extension of the arm. With such a shape, the operator can easily bring the reading port 6 into contact with the print medium-shaped symbol at an optimum angle, and the reading operation can be performed by a natural operation. The reading performance is improved and fatigue is reduced.

FIG. 6 is a cross-sectional side view showing a main part of the touch-type (contact type) code scanner 1, and FIG. 7 is a side cross-sectional view showing a configuration around the reading port 6 of the touch-type code scanner 1. It is.

The reading port 6 is a symbol interface for inputting an image of a symbol and is the location most affected by the external environment, and is a transparent acrylic resin plate or a glass plate for blocking obstructions such as dust. Is covered with a reading port cover 8 formed by the above.

The surface of the reading port cover 8 is reinforced in order to increase the durability against friction and impact. In particular, a glass plate is used as a material for preventing distortion of the read image due to the reading port cover 8, and a sapphire coating or a diamond coating is used for further strengthening the strength and hardness.

In order to illuminate the symbol on the print medium to be read, a plurality of LED illuminators 9-1 are provided inside the reading port 6 (inside the hood 7). Although not shown, -1 is composed of each LED and a diffusion lens formed of a light transmitting material such as a plastic material or a glass material that uniformly diffuses the light from each LED. There are two types of diffusion lenses, one in which the lens is formed of a material having light diffusion properties, and the other in which a transparent lens and a diffusion plate are combined.

Also, as shown in FIG.
-Reflective plate 10-1 that reflects and diffuses light emitted from -1
Can be provided on the inner wall of the reading port 6 or the inner wall of the hood 7, or the diffusion plate 10-2 can be provided on a straight optical path from the LED illumination unit 9-1 to the symbol to obtain uniform illumination for the symbol. Is effective.

The LED illuminating section 9-1 illuminates for a certain period of time or until the reading is completed by turning on (pressing) the trigger switch 4 for performing the reading operation.

Further, inside the reading port 6, a beam spot LED (target LED) is used as a spot light source.
9-2 is a position that does not interfere with the optical path from the LED illumination unit 9-1 to the symbol on the print medium and the optical path of the reflected light from the symbol to the image sensor described later. Are arranged symmetrically.

Each beam spot LED 9-2 irradiates a focused spot light, and as shown in FIG. 9, each spot light intersects at a preset read center axis (for example, at the center of the read range). (Overlap).
This makes it easy to guide the reading port 6 to the center of the symbol to be read accurately.

There is also a method of irradiating the boundary (corner, corner) of the reading range with the spot light without making the spot light overlap one point in order to clarify the reading range.

Since the target display by the spot light of the beam spot LEI) 9-2 is not necessary at the time of the actual reading operation, the OFF control is performed according to the trigger timing, and the light is turned off at the time of reading.

The reflected light of the symbol image light (symbol) incident from the reading port 6 is guided to the image sensor 11 housed in the apparatus main body 2 as described later, and the surface of the image sensor 11 Image.

The space from the reading port 6 to the image sensor 11 is an optical path of image light, and an optical path is formed by using an optical path changing component 12 such as a mirror or a prism depending on the shape of the apparatus main body 2. . For image formation, a lens block 13 composed of a lens, a diaphragm, and the like, and a filter block 1 for attenuating and removing unnecessary extraneous light are provided.
4 is disposed on the front surface of the image sensor 11 so that the image light is accurately focused on the surface of the image sensor 11. In this embodiment, the lens block 13 and the filter block 14 are formed as one block.

In the lens block 13, one lens or a combination of a plurality of lenses is selected according to the focal length and magnification, and a diaphragm mechanism or a diaphragm component is incorporated according to the amount of reflected light from the object to be read. In.

In order to minimize the image distortion caused by the lenses of the lens block 13, it is necessary to correct the image with a plurality of lenses or to employ an aspherical lens.

When a problem arises due to the occurrence of ghost due to reflection on the lens surface, a lens having a surface treated with an anti-reflection coating or the like is used.

Since the resolution of the image sensor 11 is fixed, the print size and the fineness (information density) of the symbol
In some cases, the reading process cannot be performed with sufficient accuracy. For this reason, a magnification conversion function is required to form an image on the image sensor 11 at a size suitable for reading processing in accordance with the fineness of the printing size of the symbol on the print medium.

It is not easy to change (adjust) the magnification of the lens in the lens block 13 disposed inside the apparatus main body 2. Therefore, the optical path from the reading port 6 to the image sensor 11 is fixed, and the reading port cover 7 to which the lens unit 7-1 for magnification conversion is attached to the reading port 6 as described above is attached to the apparatus. A magnification conversion function is realized by detachably replacing the main body 2.

When the structure and position of the lenses in the lens block 13 are configured to be easily adjusted (exchanged) from the outside of the apparatus main body 2, an arbitrary magnification (angle of view) can be changed depending on the design. It is possible to do.

The image sensor 11 uses an area sensor, and the single area sensor is used for both reading of a two-dimensional code and reading of a bar code.

As the area sensor, there are a method of two-dimensionally arranging the image sensors and reading an image on a surface, and a method of arranging the image sensors one-dimensionally (in a line) and reading as a line scan. .

By using a solid-state image pickup device as the image pickup device, it is possible to reduce the size and power consumption of the device, compared to an image pickup device such as a camera using an image pickup tube or the like which is not a solid-state image pickup device.
High reliability is obtained.

As the solid-state image pickup device, a CCD type, MOS
Type and CMD type. . The MOS type is characterized by low power consumption.

A circuit board 15 on which the circuit components of the reader are mounted is housed inside the grip portion. A cable attachment port for drawing out the interface cable 3 is provided at a rear portion inside the grip portion, and an internal circuit board and the interface cable 3 are connected.

The center of gravity of the code scanner 1 is located at a fulcrum for holding the code scanner which is directly touched by a hand. Gather near the support point.
By arranging in this manner, the operability and the effect of reducing fatigue can be obtained.

As shown in FIG. 10, the electric circuit is roughly divided into an image sensor unit 21, an image memory unit 22, and a CPU (central processing unit) unit 2.
3, an I / O unit 24 and a power supply unit 25. Even if each is mounted on an independent board,
Also, a plurality of units may be mixed and mounted on one board.

In order to reduce the size of the power supply unit 25,
Further, in order to facilitate the handling of the interface cable 3, and in particular to minimize the number of signal lines included in the interface cable 3 and secure its safety, the power supply unit 25 is connected to the interface cable 3. Is supplied to the low voltage D
C (DC current). The power supply unit 25
Converts the supplied low-voltage DC into a plurality of voltages required for the circuit operation and supplies the plurality of voltages to the respective circuits required for the units 21 to 24. In addition, low voltage AC
Although there is a method of supplying (alternating current), the interface cable 3 also has a signal line for other data communication, which may cause induced noise or induced voltage due to a magnetic field change of the AC current, which is not desirable. .

The formed image is converted into an electric signal by the image sensor 11. Here, the image sensor 11 is described as a CCD type.

The image sensor unit 21 includes the image sensor 11, a driver circuit for driving the image sensor 11, an amplifier circuit for amplifying a small output from the image sensor 11 with a good S / N ratio. 2 for quantizing the analog signal output from the amplifier circuit
It consists of a digitizing circuit.

As shown in FIG. 11, the output of the image sensor 11 has a shading phenomenon in which the level of the sensor output decreases at both ends of the signal (signal corresponding to the peripheral portion of the reading range) due to a decrease in optical light amount. Therefore, as shown in FIG. 12, a method of changing the reference value for quantization in the binarization circuit in accordance with the shading phenomenon is used as shading correction. There are other methods for shading correction, and the present invention is not limited to this shading correction method.

The output signal from the image sensor unit 21 is a binary signal obtained by binarizing an image and coordinates for specifying each pixel position are counted and output by a counter.

It is also effective to use the signal at the subsequent stage if the grayscale signal is output simultaneously with the binarized signal. However, the grayscale signal will be described here for simplicity. Is omitted.

The binary video signals “1” and “0” and the address coordinate value from the image sensor unit 21 are stored in the DMA (direct mem) of the image memory unit 22.
The image data is stored in a predetermined position of an image memory which is a main body of the image memory unit 22 through an or access circuit. Note that the binary video signal and the address coordinate value are
CPU unit 23 without passing through circuit A (not provided)
(CPU bus) and may be stored in a predetermined position of the image memory.

When a predetermined number (pixel number) of data constituting an image has been written, a write completion signal is output from the DMA circuit of the image memory unit 22.

When the write completion signal is output from the image memory unit 22, the CPU unit 23 sets the program memory (ROM = read only mem).
The CPU is driven based on the code decoding program stored in (ory) to decode (decode) a code value (code data) from the image data stored in the image memory.

A flash ROM is used as the program memory of the CPU unit 23. By doing so, it is possible to rewrite a program (for example, a code decoding program) via the interface cable 3 and the communication interface. By incorporating a program, optimal performance can be improved.

The decoded code value is transferred to an external device such as a host computer through the communication interface of the I / O unit 24. The communication interface is a general-purpose serial port such as RS-232C or C
A CMOS interface for transferring data at a MOS logic level, and a USB port or I
A communication interface that is considered to be the next standard such as EEE1394 is prepared. In addition, an infrared interface that does not use a cable is also practical. The communication protocol for data transfer is performed by the CPU, and the data format and the like can be freely set.

The I / O unit 24 has an I / O (input / output) that can be monitored and controlled.
Port is included. This I / O port has the L
ED illumination unit 9, the trigger switch 4, an external trigger input terminal for receiving an external trigger input, the display device 5, and a sound for informing the operator whether or not the reading process has been performed normally or the result thereof audibly. (Buzzer) is connected.

The read code type can be set by operating the trigger switch 4. . That is, FIG. 13 is a diagram showing a flow of a trigger interruption process performed by the CPU unit 23 when the trigger switch 4 is turned on. Operation), a reading process (analysis / decoding process) of a two-dimensional code (matrix code) is performed, and a barcode reading process (analysis / decoding) is performed for a long ON operation (continuous operation) in which the ON operation is continued for a preset time or longer. Processing).

The ON / OFF operation of the power supply is linked to the ON operation of the trigger switch 4 for controlling the reading operation. In other words, when the reading operation is in the OFF state, the power is also turned OFF to prevent wasteful power consumption during non-reading.

FIG. 14 is a perspective view showing a gun-type non-contact type code scanner 31, and FIG. 15 is a side sectional view showing a main part of the code scanner 31. The gun-type code scanner 31 is basically the same as the gun-type code scanner 31 except that it has two types of image sensors of an external shape, an area sensor and a linear sensor (line sensor), and has a configuration for non-contact reading. Specifically, since the touch-type code scanner 1 has the same configuration as the above-described touch-type code scanner 1, members having the same functions are denoted by the same reference numerals and description thereof will be omitted.

Inside the reading port 6 of the non-contact type code scanner 31 of the gun type, a linear illumination section 32 for a linear sensor described later and an area illumination section 33 for an area sensor described later are arranged. . These lighting units 3
Each of the reference numerals 2 and 33 includes an LED and a diffusion lens, similarly to the LED illumination unit 9 of the touch-type code scanner 1.

The read code type is set by the operation method of the trigger switch 4, and the driving of the illumination units 32 and 33 is controlled according to the read code type setting. That is, the trigger switch 4 is normally turned on and immediately turned off.
In the short ON operation, the area sensor illumination unit 33
Is driven to perform illumination, and O
In the long ON operation that continues N, the linear illumination unit 32
Is driven to perform illumination.

The illumination time of each of the illumination units 32 and 33 is determined by the L
As in the case of the ED illuminator 9, this is a fixed time or a time from when the trigger switch 4 is turned on until the reading is completed.

The spot light emitted from the beam spot LEDs 34 and 35 is, as shown in FIGS.
The irradiation ranges and directions of the spot lights are arranged so as to intersect (overlap) at a predetermined point (for example, the center of the reading range) at a predetermined focal length on the reading central axis.

The spot light irradiation angle is set so that it can be adjusted. By monitoring the spot light gathering state with an image sensor, it is possible to automatically check whether or not there is a symbol in the reading range. It has a configuration.

As described above, in this gun-type non-contact code scanner 31, in order to accurately read two-system symbols of a two-dimensional code and a bar code (one-dimensional code), each code is used. Optimum illumination is provided, and a target display using spot light is provided to match the symbol to the reading range.

Each of the illumination units 32 and 33 is driven by the operation of the trigger switch 4 to perform illumination. However, both can be driven to perform illumination without selection. . In such a case, the light emission wavelengths of the respective image sensors, which will be described later, are changed to BP so as not to affect each other's system.
If the optical filters such as F are made different, the above influence can be eliminated.

The image sensor has an area sensor 36 for reading a two-dimensional code, and a linear sensor (line sensor) 37 for reading a bar code (one-dimensional code).

These image sensors 36 and 37 are composed of solid-state image sensors like the image sensor 11 described above. The area sensor 36 is configured by arranging solid-state imaging devices in a matrix, and the linear sensor 37 is configured by arranging solid-state imaging devices in a line (one row). is there. It should be noted that a two-dimensional code can be read by providing an operation mechanism for sequentially operating the linear sensor 37 as well.

Incidentally, on the front of the area sensor 36,
An area optical mechanism 38 including a lens, an aperture, a filter, and the like for forming an image of reflected light from the symbol by the area sensor 36 is disposed.
On the front surface of the linear sensor 37, a linear optical mechanism 39 including a lens, an aperture, a filter, and the like for forming reflected light from a symbol (a bar code) into an image by the linear sensor 37.
Is arranged. A diffusion lens (cylindrical lens) 8a also serving as shading correction is provided at a position where the optical axis of the linear illumination section 32 of the reading port cover 8 passes.
Is arranged.

FIG. 18 shows a reading range 36 A of the area sensor 36 and a reading range 37 of the linear sensor 37.
FIG. Reading range 3 of the area sensor 36
6A is a region which extends in the vertical and horizontal directions so as to take in a two-dimensional code, and the reading range 37A of the linear sensor 37 extends only in one direction (lateral direction) so as to take in a barcode. Area. Generally, the extension (length) in one direction of the reading range 37A of the linear sensor 37 is equal to the reading range 36A of the area sensor 36.
Is larger than the spread in the longitudinal direction.

In the case of a reading device that can read a two-dimensional code and a one-dimensional code simultaneously, there are two methods for installing the image sensor unit.

The first method is a method in which only a unit including the area sensor 36 is used, and a two-dimensional code and a one-dimensional bar code are read by the same area sensor 36.

The second method is a method of selecting and using a unit consisting of the area sensor 36 and a unit consisting of the linear sensor 37 by a two-dimensional code and a one-dimensional bar code to be read, respectively.

In the first method, since the area sensor 36 has a smaller number of solid-state imaging devices arranged in one direction (one row or one column) than the linear sensor 37, when the area sensor 36 reads a bar code, , Barcode size and resolution will be limited. The minimum resolution and read size of the barcode that can be read are equivalent to a two-dimensional code.

In the second method, independent two-dimensional codes and bar codes (one-dimensional codes) can be used to obtain independent reading ranges and reading resolutions, and the large size currently used in the FA and distribution fields. Can be read by the linear sensor 37.

For example, 800 × 60
Using a 0 pixel CCD, 4096
Considering the case where a CCD of pixels is used, the resolution is set to O.D.
When reading a code at 25 mm / 4 pixels, the area sensor 36 has a width of 50 mm, and the linear sensor 37 has a width of 25 mm.
It can read symbols up to 6 mm wide. Therefore,
Linear sensor 3 for reading high resolution and wide barcodes
The use of 7 is more advantageous.

In general, a two-dimensional code is often printed at a high density and a bar code is printed at a low density in many cases. Therefore, a unit including an area sensor 36 and a unit including a linear sensor 37 are provided so that the resolution can be individually set. And are installed independently.

FIG. 19 is a block diagram showing a circuit configuration of a main part of the non-contact type code scanner 31 of the gun type. In terms of functional configuration, the touch-type code scanner 1 described above is used.
Although the block diagram is the same as that of the non-contact type code scanner 31, an actual circuit configuration will be described.

The area sensor unit 41 comprising the area sensor 36 additionally includes the area sensor 36
A drive circuit 42 (for an area sensor) that drives
A counter 43 (for an area sensor) that counts coordinate values based on the drive timing from the drive circuit 42
An amplification circuit 44 (for the area sensor) for amplifying the imaging signal from the area sensor 36, and a shading correction function, and convert the imaging signal amplified by the amplification circuit 44 into 0 or 1 digital data. And a binarizing circuit 45 (for an area sensor).

The linear sensor unit 46 including the linear sensor 37 additionally includes the area sensor 37.
A drive circuit 47 (for a linear sensor) that drives
A counter 48 (for a linear sensor) that counts coordinate values based on the drive timing from the drive circuit 47.
An amplification circuit 49 (for a linear sensor) for amplifying the imaging signal from the area sensor 37; and a shading correction function. The imaging signal amplified by the amplification circuit 49 is converted into a 0 or 1 digital imaging signal. (For a linear sensor).

The data selector 51 is connected to the area imaging data line from the binarization circuit 45 of the area sensor unit 41 and the coordinate data line from the counter 43, and to the binarization circuit of the linear sensor unit 46. 5
A linear imaging data line from 0 and a coordinate data line from the counter 48 are connected. This data selector 51
Is based on a selection signal generated by the CPU 52 constituting the control unit main body, one of a data line from the area sensor unit 41 and a data line from the linear sensor unit 46 is DMA (direct).
(memory access) 53 to the output data line.

The CPU 52 transmits a program memory 55, an image memory 56,
The MA 53 is connected to an I / O (input / output) port 57 and a communication interface 58. Note that the CPU 52 sends the data selector 5
1 is also output to the data selector 51 through the system bus 54.

The program memory 55 includes the CPU 52
And the like are stored.

The image memory 56 has a capacity for storing a plurality of image pickup data.
The imaging data of the unit selected by the data selector 51 is developed as image data in the image memory 56 without passing through the CPU 52 based on the coordinate data.

The I / O boat 57 has a target (beam spot LEDs 34 and 35), illumination (illumination unit 3).
2, 33), the trigger switch 4, external trigger input 5
9, a display 60 and a sounder (buzzer) 61 are connected to the assigned input / output ports.

The operation of the two-dimensional reader equipped with the two systems of the area sensor unit 41 and the linear sensor unit 46 is as follows.

The read code type is switched by the trigger switch 4
, An instruction by a command from the host computer, and automatic switching by analyzing the imaging data.

The determination of the read code type by these methods is performed by using the image data from the sensor unit that reads the determined code type as valid data, by using the data selector 51.
Can be used to control the effective data switching by instructing the connection of the output data from the sensor unit to the DMA, but memory buffers are provided in the area sensor unit 41 and the linear sensor unit 46, respectively.
By temporarily storing the image data before the data selector 51, the image data can be used to determine the order of inputting both image data to the image memory 56.

The selection signal of the data selector 41 is
2, the switching order and the like can be automatically set based on the past tendency by the learning function.

After the trigger input, the linear and area beam spot LEDs 3 indicating the code reading visual field and the reading focal position of the linear sensor 37 and the area sensor 36, respectively.
Lights 4 and 35 are turned off. After the illumination of the spot light is turned off, the imaging input of the linear sensor 37 is performed.
6 is input.

FIG. 20 is a diagram showing the drive timings of the illumination units 32 and 34 for the area and the linear, the beam spot LEDs 34 and 35 for the area and the linear, and the trigger switch 4.

The decoding algorithm realized by the program installed in the CPU 52 extracts the characteristics of the image, for example, after the end of the image pickup by the area sensor 36. This process is a process for checking whether a bar code or a two-dimensional code is present in the image.

When its existence is confirmed, decoding processing is performed to determine the success / failure of the reading. If the reading is successful, the result is displayed on the display unit 60 and transmitted and output through the communication interface 58, thus ending the processing. If unsuccessful, the cause of the failure is displayed on the display 60, the reading process is terminated, and the process returns to the trigger input waiting state.

FIG. 2 shows the first embodiment of the present invention.
This will be described with reference to FIG. In the first embodiment, the beam spot LEDs 34, 3 as target illuminating means are used.
5 and the timing of turning on / off the illuminating units 32 and 34 as symbol illuminating means, and the timing of exposing the area sensor 36 and the linear sensor 37 as image capturing means.

That is, the period a during which the illumination units 32 and 34 are turned on and the exposure period of the area sensor 36, the area sensor 36, and the linear sensor 37 are set to be the same.

In the period t1 during which the beam spot LEDs 34, 35 are turned on, the illumination units 32, 34 are turned off, and the exposure period of the area sensor 36 and the linear sensor 37 is turned off.

In the period t2 when the beam spot LEDs 34 and 35 are turned off, the illuminating units 32 and 34 are turned off.
Is turned on, and the exposure period of the area sensor 36 and the linear sensor 37 is turned on.

That is, the illumination units 32 and 34 for illuminating the symbols are turned on only during the exposure period of the area sensor 36 and the linear sensor 37.
4 can be reduced in power consumption.

In the exposure period of the area sensor 36 and the linear sensor 37, the beam spot LED 34,
35, so that the beam spot LE
The spot light emitted from D34, D35 is the area sensor 3
6 and the area sensor 36
In addition, it is possible to prevent the symbol image captured by the linear sensor 37 from being adversely affected.

Further, a second embodiment of the present invention will be described with reference to FIG. In FIG. 22, 61a
Is a first illumination unit whose illuminance can be changed, and 61d is a second illumination unit whose illuminance can be changed.

Both the first illuminating means 61a and the second illuminating means 61b have directivity, and are emitted from the first illuminating means 61a and the second illuminating means 61b at the focal length L of the imaging means. The first illuminating means 61a and the second illuminating means 61b are arranged such that the irradiation directions of the light are deviated to each other so that the spot lights intersect. The first lighting means 61a and the second lighting means 61
b constitutes the overall lighting means.

The first lighting means 61a and the second lighting means 6
1b, an imaging means 62 such as the area sensor 36.
Are arranged. A lens 63 is provided in front of the imaging means 62. Here, 64 is a symbol on the print medium.

First, the first illuminating means 61a and the second illuminating means 61b are set to illuminance suitable for the target. The first illuminating means 61a and the second illuminating means 61b thus changed to the illuminance suitable for the target constitute a target illuminating means.

The spot emitted from the first lighting means 61a and the second lighting means 61b on the symbol 64 while moving the distance between the symbol 64 and the d1 lighting means 61a and the second lighting means 61b. Look for locations where light intersects.

Next, the illuminance of the first illuminating means 61a and the second illuminating means 61b is changed to the optimum illuminance for illuminating the symbol 64. The first illuminating unit 61a and the second illuminating unit 61b whose illuminance is changed to an illumination suitable for illuminating the symbol as described above constitute a symbol illuminating unit.

The light emitted from the first illuminating means 61a and the second illuminating means 61b is reflected by the symbol 64, and is imaged as a symbol image by the imaging means 62 via the lens 63.

After that, the first illuminating means 61a and the second illuminating means 61b are returned to the illuminance suitable for the target.

As described above, in the second embodiment of the present invention, the target illuminating means and the symbol illuminating means are performed by the same unified illuminating means, so that a space for arranging the unified illuminating means is provided. Can be reduced.

Further, a third embodiment of the present invention will be described with reference to FIG. In FIG. 23, reference numeral 71 denotes a first lighting unit whose illuminance can be changed by selectively driving a plurality of LEDs. In the first lighting means 71, LEDs 71a to 71c are arranged in a vertical direction.

Further, the second lighting means 72 includes an LED.
72a to 72c are arranged in the vertical direction.

The LEs arranged on the first lighting means 71
D71a to 71c and the spotlights emitted from the LEDs 72a to 72c arranged in the second lighting means 72 are arranged such that the spotlights are biased toward each other. Each of the LEDs 71a to 71c and 72a to 72c has directivity, and the radiation direction of the light emitted from the LEDs 71b and 72b so that the spot lights emitted from the LEDs 71b and 72c intersect at the focal length L of the imaging unit. Is set in advance.

The first lighting means 71 and the second lighting means 72
An image pickup means 73 such as the area sensor 36 is provided between the two. A lens 74 is provided in front of the imaging means 73.
Are arranged. In addition, 75 is a symbol on the print medium.

Here, all the LEDs 71a to 71C, 72a to 72c of the first lighting means 71 and the second lighting means 72 are provided.
The symbol illuminating means is constituted by 72c, and the target illuminating means is constituted by the LEDs 71b and 72b which are part of the symbol illuminating means.

First, the LED 71b of the first lighting means 71
Then, only the LED 721b of the second lighting means 72 is turned on. Then, while moving the symbol 75 and the first lighting means 71 and the second lighting means 72, L
The position where the spot light emitted from the ED 71b and the LED 72b intersects is searched.

When this position is found, all the LEDs 71a to 71c and 72a to 72c arranged in the first lighting means 71 and the second lighting means 72 are turned on. Thus, by turning on all the LEDs, an illuminance suitable for illuminating the symbol 75 can be obtained. Then, the first lighting means 71 and the second lighting means 72
The light emitted from the lens 74 is reflected by the symbol 75 and
Is imaged as a symbol image by the imaging means 73 via the.

Thereafter, the first illuminating means 71 is
Only the LED b is lit, and only the LED 72b of the second illuminating means 72 is lit to return the illuminance to a level suitable for the target.

As described above, in the third embodiment of the present invention, the target illuminating means uses a part of the symbol illuminating means as the unified illuminating means, so that the unified illuminating means is arranged. Space can be reduced.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 24, 81a
Reference numerals 81b and 81b denote target illuminating means for irradiating a spot light as a target to a substantially central portion of a reading range of an imaging means described later. The target illuminating units 81a and 81b are composed of LEDs having directivity, and the target illuminating units 81a and 81b are arranged at the focal length L of the imaging unit.
The irradiation directions of the light emitted from the target illumination means 81a and 81b are arranged so as to be deviated to each other so that the spot lights emitted from 1b intersect.

Reference numeral denotes a symbol on a print medium. In FIG. 24, the symbol illuminating means for irradiating the symbol 82 is not shown.

The target illumination means 81a and the symbol 82
A polarizing plate 83 as a first polarizing unit having a vertical polarization direction is disposed between the target illumination unit 81a and the symbol 82, and a first polarizing plate having a vertical polarization direction is disposed between the target illumination unit 81a and the symbol 82. A polarizing plate 84 as polarizing means is provided.

An imaging means 85 such as the area sensor 36 is provided between the target illumination means 81a and 81b. A lens 86 is provided in front of the imaging unit 85. A polarizing plate 87 as a second polarizing means whose polarizing direction is orthogonal to the above-mentioned polarizing plates 83 and 84 is disposed in front of the lens 86.

As described above, since the polarizing plates 83, 84 and 87 are arranged, the spot light emitted from the target illumination means 81a and 81b is reflected by the symbols 82 after being polarized by the polarizing plates 83 and 84. However, since the reflected light is blocked by the polarizing plate 87 (the polarizing direction is orthogonal to the polarizing plates 83 and 84), the influence of the spot light emitted from the target lighting means 81a and 81b on the symbol image is reduced. be able to.

[0135]

According to the first aspect of the present invention, the lighting period of the symbol illuminating unit for illuminating the symbol is set to be the same as the exposure period of the imaging unit, so that the power consumption of the symbol illuminating unit is reduced. Can be. Furthermore, since the target illumination unit is turned off during the exposure period of the imaging unit, it is possible to prevent the spot light emitted from the target illumination unit from affecting the symbol image.

According to the second and third aspects of the present invention, the symbol illuminating means for illuminating the symbol and the target illuminating means for illuminating the central portion of the reading range of the imaging means with a spot light as a target are the same unified illuminating means. As a result, the space for disposing the unified lighting means can be reduced.

According to the fourth and fifth aspects of the present invention, a part of the symbol illuminating means for illuminating the symbol is used as the target illuminating means for illuminating the center of the reading range of the imaging means with the spot light as a target. Since the unified lighting means is arranged, the space for arranging the unified lighting means can be reduced. According to the sixth aspect of the invention, the spot light emitted from the target illumination means is polarized by the first polarization means and then reflected by the symbol, but the reflected light is reflected by the second polarization means (polarization direction). Is orthogonal to the first polarizing means), the influence of the spot light emitted from the target lighting means on the symbol image can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a handy type touch type code scanner common to the embodiments of the present invention.

FIG. 2 is a front sectional view showing a body case of the handy type touch code scanner.

FIG. 3 is a top view showing the handy type touch code scanner.

FIG. 4 is a perspective view showing the handy type touch code scanner main body and the hood.

FIG. 5 is a perspective view showing various hoods that can be attached to the handy type touch code scanner main body.

FIG. 6 is a side cross-sectional view showing a main configuration of the handy type touch code scanner.

FIG. 7 is a side sectional view showing a configuration around a reading port of the handy type touch code scanner.

FIG. 8 is a diagram showing a diffuse reflection plate and a diffusion plate of the handy type touch code scanner.

FIG. 9 is a perspective view showing an irradiation state of spot light on a symbol printed on a print medium of the handy type touch code scanner.

FIG. 10 is a block diagram showing a functional configuration of a main part of the handy type touch code scanner.

FIG. 11 is a view showing a shading phenomenon of the handy type touch type code scanner.

FIG. 12 is a view showing shading correction of the handy type touch code scanner.

FIG. 13 is a view showing the flow of a trigger interruption process performed by the handy type touch code scanner.

FIG. 14 is a perspective view showing a gun-type non-contact cord scanner common to the embodiments of the present invention.

FIG. 15 is a side cross-sectional view showing a main part configuration of the non-contact code scanner of the gun type.

FIG. 16 is a perspective view showing an irradiation state of spot light on a symbol printed on a print medium of the non-contact type code scanner of the same gun type.

FIG. 17 is a view for explaining the focal length of spot light of the non-contact type code scanner of the same gun type.

FIG. 18 shows a non-contact code scanner 2 of the same gun type.
The figure which shows the reading range corresponding to the kind of sensor.

FIG. 19 is a block diagram showing a main circuit configuration of the non-contact code scanner of the gun type.

FIG. 20 is a diagram showing drive timings of an area and linear illumination unit, area and linear beam spot LEDs, and a trigger switch of the non-contact type code scanner of the same gun type.

FIG. 21 is a timing chart for explaining the operation of the symbol reading device according to the first embodiment of the present invention.

FIG. 22 is a diagram showing a main configuration of a symbol reading device according to a second embodiment of the present invention.

FIG. 23 is a diagram illustrating a configuration of a main part of a symbol reading device according to a third embodiment of the present invention.

FIG. 24 is a diagram showing a main configuration of a symbol reading device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Touch-type code scanner, 4 ... Trigger switch, 6 ... Reading port, 7 ... Hood, 9-1 ... LED illumination part, 9-2, 34, 35 ... Beamsbot LED, 11 ... Image sensor, 23 ... CPU unit 31, a gun-type non-contact code scanner, 32, a linear lighting unit, 33, an area lighting unit, 36, an area sensor.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makoto Sugiyama 6-78, Minamicho, Mishima-shi, Shizuoka Pref.

Claims (6)

[Claims] 1. A symbol reading apparatus comprising: an image pickup unit configured to irradiate a symbol on a print medium with light and output an electric quantity corresponding to an amount of light received from the symbol and output the electric quantity. A symbol illuminating unit that irradiates the symbol with light; a target illuminating unit that irradiates a spot light as a target to a substantially central portion of a reading range of the imaging unit; and a target illumination unit that is turned off during an exposure period of the imaging unit. And a lighting control means for setting a lighting period of the lighting means and an exposure time of the imaging means to be the same. 2. A symbol reading apparatus comprising: an image pickup unit configured to irradiate a symbol on a print medium with light and output an amount of electricity corresponding to an amount of light reflected from the symbol, and A symbol reading device, wherein the symbol lighting means for irradiating the symbol and the target lighting means for irradiating a spot light as a target to the center of the reading range of the imaging means are the same general lighting means. 3. The general lighting means is characterized in that brightness is changed between a case where the general lighting means is used as a target lighting means and a case where the general lighting means is used as a symbol lighting means. The symbol reading device according to claim 2. 4. A symbol reading apparatus comprising: an image pickup unit configured to irradiate a symbol on a print medium with light and output a quantity of electricity corresponding to an amount of light received from the symbol, and A symbol comprising: a general illumination unit that uses a part of the symbol illumination unit that irradiates the symbol as a target illumination unit that irradiates a spot light as a target to a central portion of a reading range of the imaging unit. Reader. 5. The brightness of the general lighting means is changed between a case where the general lighting means is used as a target lighting means and a case where the general lighting means is used as a symbol lighting means. The symbol reading device according to claim 4. 6. A symbol reading device provided with an image pickup means comprising a photoelectric conversion element for irradiating a symbol on a print medium with light and outputting an electric quantity corresponding to an amount of light received from the symbol, Target illuminating means for irradiating a spot light as a target to a substantially central portion of a reading range of the imaging means; first polarizing means provided between the target illuminating means and the symbol; A second polarization means disposed between the first polarization means and the second polarization means, wherein the polarization direction of the first polarization means is orthogonal to the polarization direction of the second polarization means. Reader.