JP2002169633A - Device for discriminating presence/absence of unit mounting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to discriminate whether or not a unit is mounted without installing a discrimination line for discriminating between the presence and absence of the mounting. SOLUTION: This device has a presence-of-mounting-identifying circuit 15 to which logic signal lines 7, 9, 12 from the mounted unit 5 are connected, and a presence/absence-of-mounting-discriminating part 6 to which a signal from the presence-of-mounting-identifying circuit 15. The presence-of-mounting- identifying circuit detects the presence or absence of a signal in the logic signal line, and outputs a signal corresponding to the presence or absence of the signal to the presence/absence-of-mounting-discriminating part, which discriminates, depending on the signal from the presence-of-mounting-identifying circuit, between the presence and absence of the unit mounting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the mounting of a unit in an electronic apparatus having a plurality of detachable units.
The present invention relates to a mounting / non-mounting determination device of a unit for determining whether or not a unit is mounted.

[0002]

2. Description of the Related Art In an electronic device having a plurality of detachable units, a check operation must be performed for each unit when there is an unmounted unit or when the mounting state is incomplete. However, when the number of units was large, the operation was very troublesome and time-consuming. For this reason, recent electronic devices are provided with a function of determining the mounting state of each unit.

Referring to FIG. 5, a conventional unit mounting / non-mounting determination device will be described.

In FIG. 5, reference numeral 1 denotes an interface unit. An A unit 3 is detachably provided on the interface unit 1 via an A connector 2. The interface unit 1 has B connectors 4a,. Via the B unit 5a,
.., 5n are provided detachably.

[0005] The A unit 3 is provided with a mounting / non-mounting discriminating section 6, which has a function of discriminating whether the B units 5a, ..., 5n are mounted or not. I have. The logic signal line 9a of the A unit 3,
, 9n and the logic signal lines 7a,..., 7n (tentatively shown in the figure) provided in the interface section 1 are connected via the A connector 2, and the logic signal lines 7a and B The logic signal line 12a of the unit 5a is connected via the B connector 4a, and the logic signal line 7n and the logic signal line 12n are
They are connected via a connector 4n.

Further, the A unit 3 has discrimination lines 11a,.
, 11n are connected to the determination lines 8a,..., 8n provided in the interface unit 1 through the A connector 2, and the determination lines 8a The discrimination line 8n is connected to the discrimination line 13a provided in the B unit 5a via the discrimination line 13n provided in the B unit 5n.
Through a B connector 4n. .., 13n are grounded.

The discrimination of the B unit 5 by the mounting / non-mounting discriminating section 6 is performed as follows.

The case where the B unit 5a is mounted will be described.

When the B unit 5a is mounted, the determination line 11a is grounded via the determination line 8a and the determination line 13a. Therefore,
The determination line 11a becomes 0 potential (Low level).

Next, when the B unit 5a is not mounted, the B unit 5 side of the discrimination line 8a is not connected, and the potential of the discrimination line 8a is changed to the power supply potential (Hig).
h level).

Therefore, the mounting / non-mounting determination unit 6 can determine whether the B unit 5a is mounted or not mounted by detecting whether the potential of the determination line 11 is at a low level or a high level.

Thus, the mounting / non-mounting discrimination section 6 discriminates the discrimination lines 11a,.
By detecting the low level and the high level of each 11n, it is possible to determine whether all the B units 5a,..., 5n are mounted or not.

[0013]

In the above-described conventional unit mounting / non-mounting apparatus, one discriminating line is required for each B unit 5, and when the number of B units 5 increases, the discriminating line increases by the increase. Need to be increased. Therefore, the number of pins of the A connector 2 and the B connector 4 must be increased. If there is no room for the number of pins of the connector and it is impossible to increase the number of pins of the connector used for the determination line 8, the connector needs to be changed.

Particularly, when the number of pins of the connector cannot be increased in the case of the existing unit, when the connector has to be changed, the operation becomes very complicated, and furthermore, the cable between the units needs to be changed. There were problems such as a large change work.

The present invention has been made in view of the above circumstances, and does not require a line for determining whether the unit is mounted or not mounted.
Enables discrimination of non-mounting, reduces the number of lines provided on the unit, effectively uses connector pins, and mounts or unmounts the unit without changing the connector even when a unit is added. Is made possible.

[0016]

According to the present invention, there is provided a mounting / non-mounting identifying circuit connected to a logic signal line from a unit to be mounted, and a mounting / non-mounting determining unit to which a signal from the mounting / non-mounting identifying circuit is input. The mounting presence / absence discrimination circuit detects the presence / absence of a signal on the logic signal line and outputs a signal corresponding to the presence / absence of the signal to the mounting / non-mounting determination unit, The present invention relates to a unit mounting / non-mounting determination device for determining whether the unit is mounted / unmounted based on a signal from a mounting presence / absence identification circuit.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the same components as those shown in FIG. 5 are denoted by the same reference numerals.

In this embodiment, the interface unit 1
The A unit 3, the B units 5a,..., 5n are not provided with a determination line.

The interface unit 1 has logic signal lines 7a,..., 7n, the A unit 3 has logic signal lines 9a,.
5n are provided with logic signal lines 12a,..., 12n, respectively.
Each of the corresponding logic signal lines is connected via a B connector 4a,..., 4n in a state where the B units 5a,.

The A unit 3 is provided with a mounting / non-mounting discriminating section 6 and mounting presence / absence discriminating circuits 15a,..., 15n of a number equal to or greater than the number of mounted B units 5a,. .., 15n are connected to the mounting / non-mounting discrimination unit 6.

The presence / absence identification circuit 15a is connected to the logic signal line 9a, and the presence / absence identification circuit 15n is connected to the logic signal line 9n. Is connected.

Although one logic signal line 7 from the B unit 5 to the A unit 3 is shown in FIG.
A logic signal line 7 corresponding to the number of pins of the B connector 4 at the maximum is provided. Therefore, the mounting presence / absence discrimination circuit 15 is connected to an appropriate one of the logic signal lines from each B unit 5.

For example, when the B unit 5a is mounted, a high level or low level signal always flows through the logic signal line 9a. The mounting presence / absence discrimination circuit 15a detects a signal regardless of whether a high-level signal or a low-level signal flows, and outputs a detection signal indicating that there is a signal on the logic signal line 9 to the mounting / non-mounting determination unit 6. I do.

When the mounting / non-mounting discriminating section 6 receives a signal from the mounting / non-mounting identifying circuit 15a, it determines that the B unit 5a is mounted.

The mounting / non-mounting discrimination unit 6 monitors all B signals by monitoring the presence / absence of a signal from the mounting presence / absence discriminating circuits 15a,..., 15n corresponding to the logic signal lines 9a,. It is possible to determine whether or not the units 5a,..., 5n are mounted.

[0027]

Next, the mounting presence / absence discriminating circuits 15a,.
A specific example of 5n will be described. , 15n have the same configuration, and will be described with reference to FIG.

The mounting presence / absence discrimination circuit 15 uses an exclusive OR gate (EX-ORGATE, hereinafter referred to as an EX-OR gate) 20.

Pull-up resistor 2 for power supply line 21
2, a first diode 23, a second diode 24, a third diode 25, a fourth diode 26, and a pull-down resistor 27 are connected in series, and the pull-down resistor 27 is grounded.

The A input of the EX-OR gate 20 is connected between the pull-up resistor 22 and the first diode 23 (Y
B) of the EX-OR gate 20 is connected between the fourth diode 26 and the pull-down resistor 27 (point Z), and the logic signal line 9 is connected to the second diode 24 3 between diode 25 (X
Point).

Each of the diodes 23, 24, 25, 26
Have the same electrical characteristics, and the pull-up resistor 22,
The pull-down resistor 27 has the same resistance value. Actually, a logic IC in which these are configured, for example, CMOS
An IC is used.

Hereinafter, the operation will be described.

First, the input / output state of the EX-OR gate 20 will be described with reference to FIG.

When the signal levels of the A input section and the B input section of the EX-OR gate 20 are both High level and Low level, the output of the EX-OR gate 20 is Lo.
When one of the signal levels to the w level and the A input section and the B input section is Low level and the other is High level, the above EX is used.
-The output of the OR gate 20 becomes High level.

Further, when the CMOS IC is used, the low level detection voltage is 1.35 Vmax,
The high level detection voltage is 3.15 Vmin. Further, a voltage of 5 V is supplied to the mounting presence / absence discrimination circuit 15, and a voltage of 5 V is applied to the power supply line 21 to which the pull-up resistor 22 is connected. The power supply line 21 is 5
In the state of V, the voltage drop of one diode is 0.6
V.

When the B units 5a,..., 5n are mounted, the logic signal lines corresponding to the respective B units 5 become Hi.
A gh level or Low level signal always occurs. Therefore, the logic signal lines 9a,.
Either the h level signal or the low level signal is always input.

First, when a low level signal is input to the point X from the logic signal line 9, the point X becomes 0V (ground potential), and the point Z naturally becomes 0V. Since the voltage drop of the first diode 23 and the second diode 24 is 1.2V in total, the potential at the point Y is 1.2V. As described above, since the low-level detection voltage of the EX-OR gate 20 is 1.35 V max, a low-level signal is input to the A input unit and the B input unit.

Therefore, the EX-OR gate 20 outputs L
An ow level signal is output.

Next, when a High level signal is input to the point X from the logic signal line 9, the point X becomes 5V, and the point Y also becomes 5V. Accordingly, a high level signal is input to the A input section. Since the potential at the point Z is obtained by subtracting the voltage drop of the third diode 25 and the fourth diode 26 from the potential at the point X,
It becomes 3.8V. High level detection voltage is 3.15V
Therefore, a high level signal is input to the B input unit.

Therefore, also in this case, a low level signal is output from the EX-OR gate 20.

Further, when the B unit 5 is not mounted, no signal is inputted to the point X, so that the potential at the point X is supplied to the power supply line 2 by the pull-up resistor 22 and the pull-down resistor 27.
1 is divided into the middle point of 5V and the ground potential of 0V,
V. Therefore, the potential at the point Y becomes 3.7 V due to the addition of the forward voltage of the first diode 23 and the second diode 24. Since the high level detection voltage of the EX-OR gate 20 is 3.15 Vmin, H is input to the A input unit.
The high level signal is input.

On the other hand, the potential at the point Z is 1.3 V because it is a value obtained by subtracting the forward voltage of the third diode 25 and the fourth diode 26 from the potential at the point X. The low level detection voltage of the EX-OR gate 20 is 1.35 V max.
Therefore, a Low level signal is input to the B input unit.

The EX-OR gate 20 outputs a high level signal.

As described above, when the B unit 5 is mounted, a low level signal is output from the EX-OR gate 20. When the B unit 5 is not mounted, the EX-OR gate 20 outputs a low level signal. Outputs a High level signal.

When the signal input from the mounting presence / absence discriminating circuit 15 is a Low level signal, the mounting / non-mounting determining section 6 determines that the B unit 5 is mounted,
If the signal is a high level signal, it is determined that the B unit 5 is not mounted.

The above operation is summarized in FIG.

In the above embodiment, the high level signal, L
Although the mounting state can be determined by any of the low-level signals, for example, a high-level signal or a low-level signal is detected so as to detect only one of the high-level signal and the low-level signal.
When there is an h level signal, it may be determined that the B unit 5 is mounted. In this case, the time width to be detected is set, and when there is a High level signal at least once within the set time width, it is determined that the B unit 5 is mounted.

[0048]

As described above, according to the present invention, a mounting / non-mounting identifying circuit connected to a logic signal line from a unit to be mounted, and a mounting / non-mounting determination to which a signal from the mounting / non-mounting identifying circuit is input. The mounting / non-mounting determining circuit detects the presence / absence of a signal on the logic signal line and outputs a signal corresponding to the presence / absence of the signal to the mounting / non-mounting determining section, Determines whether the unit is mounted or not mounted on the basis of a signal from the mounting presence / absence circuit, so that an interface for detecting whether the unit is mounted or not mounted is not required. Therefore, a connector for an interface for detecting whether the unit is mounted or not mounted is provided. It has excellent effects such as an increase in the number of connector pins and a change in cables.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an example of a mounting presence / absence identifying circuit in the embodiment;

FIG. 3 is a truth table of an EX-OR gate used in the mounting presence / absence identifying circuit.

FIG. 4 is a table showing a correspondence between an input / output state of the EX-OR gate and a judgment of a mounted / unmounted determining unit.

FIG. 5 is a schematic view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Interface part 3 A unit 5 B unit 6 Mounting / non-mounting discrimination part 7 Logic signal line 9 Logic signal line 15 Mounting presence / absence discrimination circuit 20 EX-OR gate

Claims (1)

[Claims] 1. A mounting / non-mounting discriminating circuit for connecting to a logic signal line from a unit to be mounted, and a mounting / non-mounting discrimination unit to which a signal from the mounting / non-mounting identifying circuit is inputted. The circuit detects the presence / absence of a signal on the logic signal line and outputs a signal corresponding to the presence / absence of the signal to the mounting / non-mounting discriminating unit. A mounting / non-mounting determination device for determining whether the unit is mounted or not mounted based on the determination.